From c167b9c7e3d6131b4a4865c112a3dbc86d2e997d Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Mon, 21 Dec 2020 19:39:51 +0100 Subject: platform/surface: Add Surface Aggregator subsystem Add Surface System Aggregator Module core and Surface Serial Hub driver, required for the embedded controller found on Microsoft Surface devices. The Surface System Aggregator Module (SSAM, SAM or Surface Aggregator) is an embedded controller (EC) found on 4th and later generation Microsoft Surface devices, with the exception of the Surface Go series. This EC provides various functionality, depending on the device in question. This can include battery status and thermal reporting (5th and later generations), but also HID keyboard (6th+) and touchpad input (7th+) on Surface Laptop and Surface Book 3 series devices. This patch provides the basic necessities for communication with the SAM EC on 5th and later generation devices. On these devices, the EC provides an interface that acts as serial device, called the Surface Serial Hub (SSH). 4th generation devices, on which the EC interface is provided via an HID-over-I2C device, are not supported by this patch. Specifically, this patch adds a driver for the SSH device (device HID MSHW0084 in ACPI), as well as a controller structure and associated API. This represents the functional core of the Surface Aggregator kernel subsystem, introduced with this patch, and will be expanded upon in subsequent commits. The SSH driver acts as the main attachment point for this subsystem and sets-up and manages the controller structure. The controller in turn provides a basic communication interface, allowing to send requests from host to EC and receiving the corresponding responses, as well as managing and receiving events, sent from EC to host. It is structured into multiple layers, with the top layer presenting the API used by other kernel drivers and the lower layers modeled after the serial protocol used for communication. Said other drivers are then responsible for providing the (Surface model specific) functionality accessible through the EC (e.g. battery status reporting, thermal information, ...) via said controller structure and API, and will be added in future commits. Signed-off-by: Maximilian Luz Link: https://lore.kernel.org/r/20201221183959.1186143-2-luzmaximilian@gmail.com Signed-off-by: Hans de Goede --- include/linux/surface_aggregator/controller.h | 824 ++++++++++++++++++++++++++ include/linux/surface_aggregator/serial_hub.h | 672 +++++++++++++++++++++ 2 files changed, 1496 insertions(+) create mode 100644 include/linux/surface_aggregator/controller.h create mode 100644 include/linux/surface_aggregator/serial_hub.h (limited to 'include') diff --git a/include/linux/surface_aggregator/controller.h b/include/linux/surface_aggregator/controller.h new file mode 100644 index 000000000000..f4b1ba887384 --- /dev/null +++ b/include/linux/surface_aggregator/controller.h @@ -0,0 +1,824 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Surface System Aggregator Module (SSAM) controller interface. + * + * Main communication interface for the SSAM EC. Provides a controller + * managing access and communication to and from the SSAM EC, as well as main + * communication structures and definitions. + * + * Copyright (C) 2019-2020 Maximilian Luz + */ + +#ifndef _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H +#define _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H + +#include +#include +#include + +#include + + +/* -- Main data types and definitions --------------------------------------- */ + +/** + * enum ssam_event_flags - Flags for enabling/disabling SAM events + * @SSAM_EVENT_SEQUENCED: The event will be sent via a sequenced data frame. + */ +enum ssam_event_flags { + SSAM_EVENT_SEQUENCED = BIT(0), +}; + +/** + * struct ssam_event - SAM event sent from the EC to the host. + * @target_category: Target category of the event source. See &enum ssam_ssh_tc. + * @target_id: Target ID of the event source. + * @command_id: Command ID of the event. + * @instance_id: Instance ID of the event source. + * @length: Length of the event payload in bytes. + * @data: Event payload data. + */ +struct ssam_event { + u8 target_category; + u8 target_id; + u8 command_id; + u8 instance_id; + u16 length; + u8 data[]; +}; + +/** + * enum ssam_request_flags - Flags for SAM requests. + * + * @SSAM_REQUEST_HAS_RESPONSE: + * Specifies that the request expects a response. If not set, the request + * will be directly completed after its underlying packet has been + * transmitted. If set, the request transport system waits for a response + * of the request. + * + * @SSAM_REQUEST_UNSEQUENCED: + * Specifies that the request should be transmitted via an unsequenced + * packet. If set, the request must not have a response, meaning that this + * flag and the %SSAM_REQUEST_HAS_RESPONSE flag are mutually exclusive. + */ +enum ssam_request_flags { + SSAM_REQUEST_HAS_RESPONSE = BIT(0), + SSAM_REQUEST_UNSEQUENCED = BIT(1), +}; + +/** + * struct ssam_request - SAM request description. + * @target_category: Category of the request's target. See &enum ssam_ssh_tc. + * @target_id: ID of the request's target. + * @command_id: Command ID of the request. + * @instance_id: Instance ID of the request's target. + * @flags: Flags for the request. See &enum ssam_request_flags. + * @length: Length of the request payload in bytes. + * @payload: Request payload data. + * + * This struct fully describes a SAM request with payload. It is intended to + * help set up the actual transport struct, e.g. &struct ssam_request_sync, + * and specifically its raw message data via ssam_request_write_data(). + */ +struct ssam_request { + u8 target_category; + u8 target_id; + u8 command_id; + u8 instance_id; + u16 flags; + u16 length; + const u8 *payload; +}; + +/** + * struct ssam_response - Response buffer for SAM request. + * @capacity: Capacity of the buffer, in bytes. + * @length: Length of the actual data stored in the memory pointed to by + * @pointer, in bytes. Set by the transport system. + * @pointer: Pointer to the buffer's memory, storing the response payload data. + */ +struct ssam_response { + size_t capacity; + size_t length; + u8 *pointer; +}; + +struct ssam_controller; + +struct ssam_controller *ssam_get_controller(void); +struct ssam_controller *ssam_client_bind(struct device *client); +int ssam_client_link(struct ssam_controller *ctrl, struct device *client); + +struct device *ssam_controller_device(struct ssam_controller *c); + +struct ssam_controller *ssam_controller_get(struct ssam_controller *c); +void ssam_controller_put(struct ssam_controller *c); + +void ssam_controller_statelock(struct ssam_controller *c); +void ssam_controller_stateunlock(struct ssam_controller *c); + +ssize_t ssam_request_write_data(struct ssam_span *buf, + struct ssam_controller *ctrl, + const struct ssam_request *spec); + + +/* -- Synchronous request interface. ---------------------------------------- */ + +/** + * struct ssam_request_sync - Synchronous SAM request struct. + * @base: Underlying SSH request. + * @comp: Completion used to signal full completion of the request. After the + * request has been submitted, this struct may only be modified or + * deallocated after the completion has been signaled. + * request has been submitted, + * @resp: Buffer to store the response. + * @status: Status of the request, set after the base request has been + * completed or has failed. + */ +struct ssam_request_sync { + struct ssh_request base; + struct completion comp; + struct ssam_response *resp; + int status; +}; + +int ssam_request_sync_alloc(size_t payload_len, gfp_t flags, + struct ssam_request_sync **rqst, + struct ssam_span *buffer); + +void ssam_request_sync_free(struct ssam_request_sync *rqst); + +int ssam_request_sync_init(struct ssam_request_sync *rqst, + enum ssam_request_flags flags); + +/** + * ssam_request_sync_set_data - Set message data of a synchronous request. + * @rqst: The request. + * @ptr: Pointer to the request message data. + * @len: Length of the request message data. + * + * Set the request message data of a synchronous request. The provided buffer + * needs to live until the request has been completed. + */ +static inline void ssam_request_sync_set_data(struct ssam_request_sync *rqst, + u8 *ptr, size_t len) +{ + ssh_request_set_data(&rqst->base, ptr, len); +} + +/** + * ssam_request_sync_set_resp - Set response buffer of a synchronous request. + * @rqst: The request. + * @resp: The response buffer. + * + * Sets the response buffer of a synchronous request. This buffer will store + * the response of the request after it has been completed. May be %NULL if no + * response is expected. + */ +static inline void ssam_request_sync_set_resp(struct ssam_request_sync *rqst, + struct ssam_response *resp) +{ + rqst->resp = resp; +} + +int ssam_request_sync_submit(struct ssam_controller *ctrl, + struct ssam_request_sync *rqst); + +/** + * ssam_request_sync_wait - Wait for completion of a synchronous request. + * @rqst: The request to wait for. + * + * Wait for completion and release of a synchronous request. After this + * function terminates, the request is guaranteed to have left the transport + * system. After successful submission of a request, this function must be + * called before accessing the response of the request, freeing the request, + * or freeing any of the buffers associated with the request. + * + * This function must not be called if the request has not been submitted yet + * and may lead to a deadlock/infinite wait if a subsequent request submission + * fails in that case, due to the completion never triggering. + * + * Return: Returns the status of the given request, which is set on completion + * of the packet. This value is zero on success and negative on failure. + */ +static inline int ssam_request_sync_wait(struct ssam_request_sync *rqst) +{ + wait_for_completion(&rqst->comp); + return rqst->status; +} + +int ssam_request_sync(struct ssam_controller *ctrl, + const struct ssam_request *spec, + struct ssam_response *rsp); + +int ssam_request_sync_with_buffer(struct ssam_controller *ctrl, + const struct ssam_request *spec, + struct ssam_response *rsp, + struct ssam_span *buf); + +/** + * ssam_request_sync_onstack - Execute a synchronous request on the stack. + * @ctrl: The controller via which the request is submitted. + * @rqst: The request specification. + * @rsp: The response buffer. + * @payload_len: The (maximum) request payload length. + * + * Allocates a synchronous request with specified payload length on the stack, + * fully initializes it via the provided request specification, submits it, + * and finally waits for its completion before returning its status. This + * helper macro essentially allocates the request message buffer on the stack + * and then calls ssam_request_sync_with_buffer(). + * + * Note: The @payload_len parameter specifies the maximum payload length, used + * for buffer allocation. The actual payload length may be smaller. + * + * Return: Returns the status of the request or any failure during setup, i.e. + * zero on success and a negative value on failure. + */ +#define ssam_request_sync_onstack(ctrl, rqst, rsp, payload_len) \ + ({ \ + u8 __data[SSH_COMMAND_MESSAGE_LENGTH(payload_len)]; \ + struct ssam_span __buf = { &__data[0], ARRAY_SIZE(__data) }; \ + \ + ssam_request_sync_with_buffer(ctrl, rqst, rsp, &__buf); \ + }) + +/** + * __ssam_retry - Retry request in case of I/O errors or timeouts. + * @request: The request function to execute. Must return an integer. + * @n: Number of tries. + * @args: Arguments for the request function. + * + * Executes the given request function, i.e. calls @request. In case the + * request returns %-EREMOTEIO (indicates I/O error) or %-ETIMEDOUT (request + * or underlying packet timed out), @request will be re-executed again, up to + * @n times in total. + * + * Return: Returns the return value of the last execution of @request. + */ +#define __ssam_retry(request, n, args...) \ + ({ \ + int __i, __s = 0; \ + \ + for (__i = (n); __i > 0; __i--) { \ + __s = request(args); \ + if (__s != -ETIMEDOUT && __s != -EREMOTEIO) \ + break; \ + } \ + __s; \ + }) + +/** + * ssam_retry - Retry request in case of I/O errors or timeouts up to three + * times in total. + * @request: The request function to execute. Must return an integer. + * @args: Arguments for the request function. + * + * Executes the given request function, i.e. calls @request. In case the + * request returns %-EREMOTEIO (indicates I/O error) or -%ETIMEDOUT (request + * or underlying packet timed out), @request will be re-executed again, up to + * three times in total. + * + * See __ssam_retry() for a more generic macro for this purpose. + * + * Return: Returns the return value of the last execution of @request. + */ +#define ssam_retry(request, args...) \ + __ssam_retry(request, 3, args) + +/** + * struct ssam_request_spec - Blue-print specification of SAM request. + * @target_category: Category of the request's target. See &enum ssam_ssh_tc. + * @target_id: ID of the request's target. + * @command_id: Command ID of the request. + * @instance_id: Instance ID of the request's target. + * @flags: Flags for the request. See &enum ssam_request_flags. + * + * Blue-print specification for a SAM request. This struct describes the + * unique static parameters of a request (i.e. type) without specifying any of + * its instance-specific data (e.g. payload). It is intended to be used as base + * for defining simple request functions via the + * ``SSAM_DEFINE_SYNC_REQUEST_x()`` family of macros. + */ +struct ssam_request_spec { + u8 target_category; + u8 target_id; + u8 command_id; + u8 instance_id; + u8 flags; +}; + +/** + * struct ssam_request_spec_md - Blue-print specification for multi-device SAM + * request. + * @target_category: Category of the request's target. See &enum ssam_ssh_tc. + * @command_id: Command ID of the request. + * @flags: Flags for the request. See &enum ssam_request_flags. + * + * Blue-print specification for a multi-device SAM request, i.e. a request + * that is applicable to multiple device instances, described by their + * individual target and instance IDs. This struct describes the unique static + * parameters of a request (i.e. type) without specifying any of its + * instance-specific data (e.g. payload) and without specifying any of its + * device specific IDs (i.e. target and instance ID). It is intended to be + * used as base for defining simple multi-device request functions via the + * ``SSAM_DEFINE_SYNC_REQUEST_MD_x()`` and ``SSAM_DEFINE_SYNC_REQUEST_CL_x()`` + * families of macros. + */ +struct ssam_request_spec_md { + u8 target_category; + u8 command_id; + u8 flags; +}; + +/** + * SSAM_DEFINE_SYNC_REQUEST_N() - Define synchronous SAM request function + * with neither argument nor return value. + * @name: Name of the generated function. + * @spec: Specification (&struct ssam_request_spec) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request having neither argument nor return value. The + * generated function takes care of setting up the request struct and buffer + * allocation, as well as execution of the request itself, returning once the + * request has been fully completed. The required transport buffer will be + * allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_controller + * *ctrl)``, returning the status of the request, which is zero on success and + * negative on failure. The ``ctrl`` parameter is the controller via which the + * request is being sent. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_N(name, spec...) \ + int name(struct ssam_controller *ctrl) \ + { \ + struct ssam_request_spec s = (struct ssam_request_spec)spec; \ + struct ssam_request rqst; \ + \ + rqst.target_category = s.target_category; \ + rqst.target_id = s.target_id; \ + rqst.command_id = s.command_id; \ + rqst.instance_id = s.instance_id; \ + rqst.flags = s.flags; \ + rqst.length = 0; \ + rqst.payload = NULL; \ + \ + return ssam_request_sync_onstack(ctrl, &rqst, NULL, 0); \ + } + +/** + * SSAM_DEFINE_SYNC_REQUEST_W() - Define synchronous SAM request function with + * argument. + * @name: Name of the generated function. + * @atype: Type of the request's argument. + * @spec: Specification (&struct ssam_request_spec) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request taking an argument of type @atype and having no + * return value. The generated function takes care of setting up the request + * struct, buffer allocation, as well as execution of the request itself, + * returning once the request has been fully completed. The required transport + * buffer will be allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_controller + * *ctrl, const atype *arg)``, returning the status of the request, which is + * zero on success and negative on failure. The ``ctrl`` parameter is the + * controller via which the request is sent. The request argument is specified + * via the ``arg`` pointer. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_W(name, atype, spec...) \ + int name(struct ssam_controller *ctrl, const atype *arg) \ + { \ + struct ssam_request_spec s = (struct ssam_request_spec)spec; \ + struct ssam_request rqst; \ + \ + rqst.target_category = s.target_category; \ + rqst.target_id = s.target_id; \ + rqst.command_id = s.command_id; \ + rqst.instance_id = s.instance_id; \ + rqst.flags = s.flags; \ + rqst.length = sizeof(atype); \ + rqst.payload = (u8 *)arg; \ + \ + return ssam_request_sync_onstack(ctrl, &rqst, NULL, \ + sizeof(atype)); \ + } + +/** + * SSAM_DEFINE_SYNC_REQUEST_R() - Define synchronous SAM request function with + * return value. + * @name: Name of the generated function. + * @rtype: Type of the request's return value. + * @spec: Specification (&struct ssam_request_spec) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request taking no argument but having a return value of + * type @rtype. The generated function takes care of setting up the request + * and response structs, buffer allocation, as well as execution of the + * request itself, returning once the request has been fully completed. The + * required transport buffer will be allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_controller + * *ctrl, rtype *ret)``, returning the status of the request, which is zero on + * success and negative on failure. The ``ctrl`` parameter is the controller + * via which the request is sent. The request's return value is written to the + * memory pointed to by the ``ret`` parameter. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_R(name, rtype, spec...) \ + int name(struct ssam_controller *ctrl, rtype *ret) \ + { \ + struct ssam_request_spec s = (struct ssam_request_spec)spec; \ + struct ssam_request rqst; \ + struct ssam_response rsp; \ + int status; \ + \ + rqst.target_category = s.target_category; \ + rqst.target_id = s.target_id; \ + rqst.command_id = s.command_id; \ + rqst.instance_id = s.instance_id; \ + rqst.flags = s.flags | SSAM_REQUEST_HAS_RESPONSE; \ + rqst.length = 0; \ + rqst.payload = NULL; \ + \ + rsp.capacity = sizeof(rtype); \ + rsp.length = 0; \ + rsp.pointer = (u8 *)ret; \ + \ + status = ssam_request_sync_onstack(ctrl, &rqst, &rsp, 0); \ + if (status) \ + return status; \ + \ + if (rsp.length != sizeof(rtype)) { \ + struct device *dev = ssam_controller_device(ctrl); \ + dev_err(dev, \ + "rqst: invalid response length, expected %zu, got %zu (tc: %#04x, cid: %#04x)", \ + sizeof(rtype), rsp.length, rqst.target_category,\ + rqst.command_id); \ + return -EIO; \ + } \ + \ + return 0; \ + } + +/** + * SSAM_DEFINE_SYNC_REQUEST_MD_N() - Define synchronous multi-device SAM + * request function with neither argument nor return value. + * @name: Name of the generated function. + * @spec: Specification (&struct ssam_request_spec_md) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request having neither argument nor return value. Device + * specifying parameters are not hard-coded, but instead must be provided to + * the function. The generated function takes care of setting up the request + * struct, buffer allocation, as well as execution of the request itself, + * returning once the request has been fully completed. The required transport + * buffer will be allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_controller + * *ctrl, u8 tid, u8 iid)``, returning the status of the request, which is + * zero on success and negative on failure. The ``ctrl`` parameter is the + * controller via which the request is sent, ``tid`` the target ID for the + * request, and ``iid`` the instance ID. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_MD_N(name, spec...) \ + int name(struct ssam_controller *ctrl, u8 tid, u8 iid) \ + { \ + struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \ + struct ssam_request rqst; \ + \ + rqst.target_category = s.target_category; \ + rqst.target_id = tid; \ + rqst.command_id = s.command_id; \ + rqst.instance_id = iid; \ + rqst.flags = s.flags; \ + rqst.length = 0; \ + rqst.payload = NULL; \ + \ + return ssam_request_sync_onstack(ctrl, &rqst, NULL, 0); \ + } + +/** + * SSAM_DEFINE_SYNC_REQUEST_MD_W() - Define synchronous multi-device SAM + * request function with argument. + * @name: Name of the generated function. + * @atype: Type of the request's argument. + * @spec: Specification (&struct ssam_request_spec_md) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request taking an argument of type @atype and having no + * return value. Device specifying parameters are not hard-coded, but instead + * must be provided to the function. The generated function takes care of + * setting up the request struct, buffer allocation, as well as execution of + * the request itself, returning once the request has been fully completed. + * The required transport buffer will be allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_controller + * *ctrl, u8 tid, u8 iid, const atype *arg)``, returning the status of the + * request, which is zero on success and negative on failure. The ``ctrl`` + * parameter is the controller via which the request is sent, ``tid`` the + * target ID for the request, and ``iid`` the instance ID. The request argument + * is specified via the ``arg`` pointer. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_MD_W(name, atype, spec...) \ + int name(struct ssam_controller *ctrl, u8 tid, u8 iid, const atype *arg)\ + { \ + struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \ + struct ssam_request rqst; \ + \ + rqst.target_category = s.target_category; \ + rqst.target_id = tid; \ + rqst.command_id = s.command_id; \ + rqst.instance_id = iid; \ + rqst.flags = s.flags; \ + rqst.length = sizeof(atype); \ + rqst.payload = (u8 *)arg; \ + \ + return ssam_request_sync_onstack(ctrl, &rqst, NULL, \ + sizeof(atype)); \ + } + +/** + * SSAM_DEFINE_SYNC_REQUEST_MD_R() - Define synchronous multi-device SAM + * request function with return value. + * @name: Name of the generated function. + * @rtype: Type of the request's return value. + * @spec: Specification (&struct ssam_request_spec_md) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request taking no argument but having a return value of + * type @rtype. Device specifying parameters are not hard-coded, but instead + * must be provided to the function. The generated function takes care of + * setting up the request and response structs, buffer allocation, as well as + * execution of the request itself, returning once the request has been fully + * completed. The required transport buffer will be allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_controller + * *ctrl, u8 tid, u8 iid, rtype *ret)``, returning the status of the request, + * which is zero on success and negative on failure. The ``ctrl`` parameter is + * the controller via which the request is sent, ``tid`` the target ID for the + * request, and ``iid`` the instance ID. The request's return value is written + * to the memory pointed to by the ``ret`` parameter. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_MD_R(name, rtype, spec...) \ + int name(struct ssam_controller *ctrl, u8 tid, u8 iid, rtype *ret) \ + { \ + struct ssam_request_spec_md s = (struct ssam_request_spec_md)spec; \ + struct ssam_request rqst; \ + struct ssam_response rsp; \ + int status; \ + \ + rqst.target_category = s.target_category; \ + rqst.target_id = tid; \ + rqst.command_id = s.command_id; \ + rqst.instance_id = iid; \ + rqst.flags = s.flags | SSAM_REQUEST_HAS_RESPONSE; \ + rqst.length = 0; \ + rqst.payload = NULL; \ + \ + rsp.capacity = sizeof(rtype); \ + rsp.length = 0; \ + rsp.pointer = (u8 *)ret; \ + \ + status = ssam_request_sync_onstack(ctrl, &rqst, &rsp, 0); \ + if (status) \ + return status; \ + \ + if (rsp.length != sizeof(rtype)) { \ + struct device *dev = ssam_controller_device(ctrl); \ + dev_err(dev, \ + "rqst: invalid response length, expected %zu, got %zu (tc: %#04x, cid: %#04x)", \ + sizeof(rtype), rsp.length, rqst.target_category,\ + rqst.command_id); \ + return -EIO; \ + } \ + \ + return 0; \ + } + + +/* -- Event notifier/callbacks. --------------------------------------------- */ + +#define SSAM_NOTIF_STATE_SHIFT 2 +#define SSAM_NOTIF_STATE_MASK ((1 << SSAM_NOTIF_STATE_SHIFT) - 1) + +/** + * enum ssam_notif_flags - Flags used in return values from SSAM notifier + * callback functions. + * + * @SSAM_NOTIF_HANDLED: + * Indicates that the notification has been handled. This flag should be + * set by the handler if the handler can act/has acted upon the event + * provided to it. This flag should not be set if the handler is not a + * primary handler intended for the provided event. + * + * If this flag has not been set by any handler after the notifier chain + * has been traversed, a warning will be emitted, stating that the event + * has not been handled. + * + * @SSAM_NOTIF_STOP: + * Indicates that the notifier traversal should stop. If this flag is + * returned from a notifier callback, notifier chain traversal will + * immediately stop and any remaining notifiers will not be called. This + * flag is automatically set when ssam_notifier_from_errno() is called + * with a negative error value. + */ +enum ssam_notif_flags { + SSAM_NOTIF_HANDLED = BIT(0), + SSAM_NOTIF_STOP = BIT(1), +}; + +struct ssam_event_notifier; + +typedef u32 (*ssam_notifier_fn_t)(struct ssam_event_notifier *nf, + const struct ssam_event *event); + +/** + * struct ssam_notifier_block - Base notifier block for SSAM event + * notifications. + * @node: The node for the list of notifiers. + * @fn: The callback function of this notifier. This function takes the + * respective notifier block and event as input and should return + * a notifier value, which can either be obtained from the flags + * provided in &enum ssam_notif_flags, converted from a standard + * error value via ssam_notifier_from_errno(), or a combination of + * both (e.g. ``ssam_notifier_from_errno(e) | SSAM_NOTIF_HANDLED``). + * @priority: Priority value determining the order in which notifier callbacks + * will be called. A higher value means higher priority, i.e. the + * associated callback will be executed earlier than other (lower + * priority) callbacks. + */ +struct ssam_notifier_block { + struct list_head node; + ssam_notifier_fn_t fn; + int priority; +}; + +/** + * ssam_notifier_from_errno() - Convert standard error value to notifier + * return code. + * @err: The error code to convert, must be negative (in case of failure) or + * zero (in case of success). + * + * Return: Returns the notifier return value obtained by converting the + * specified @err value. In case @err is negative, the %SSAM_NOTIF_STOP flag + * will be set, causing notifier call chain traversal to abort. + */ +static inline u32 ssam_notifier_from_errno(int err) +{ + if (WARN_ON(err > 0) || err == 0) + return 0; + else + return ((-err) << SSAM_NOTIF_STATE_SHIFT) | SSAM_NOTIF_STOP; +} + +/** + * ssam_notifier_to_errno() - Convert notifier return code to standard error + * value. + * @ret: The notifier return value to convert. + * + * Return: Returns the negative error value encoded in @ret or zero if @ret + * indicates success. + */ +static inline int ssam_notifier_to_errno(u32 ret) +{ + return -(ret >> SSAM_NOTIF_STATE_SHIFT); +} + + +/* -- Event/notification registry. ------------------------------------------ */ + +/** + * struct ssam_event_registry - Registry specification used for enabling events. + * @target_category: Target category for the event registry requests. + * @target_id: Target ID for the event registry requests. + * @cid_enable: Command ID for the event-enable request. + * @cid_disable: Command ID for the event-disable request. + * + * This struct describes a SAM event registry via the minimal collection of + * SAM IDs specifying the requests to use for enabling and disabling an event. + * The individual event to be enabled/disabled itself is specified via &struct + * ssam_event_id. + */ +struct ssam_event_registry { + u8 target_category; + u8 target_id; + u8 cid_enable; + u8 cid_disable; +}; + +/** + * struct ssam_event_id - Unique event ID used for enabling events. + * @target_category: Target category of the event source. + * @instance: Instance ID of the event source. + * + * This struct specifies the event to be enabled/disabled via an externally + * provided registry. It does not specify the registry to be used itself, this + * is done via &struct ssam_event_registry. + */ +struct ssam_event_id { + u8 target_category; + u8 instance; +}; + +/** + * enum ssam_event_mask - Flags specifying how events are matched to notifiers. + * + * @SSAM_EVENT_MASK_NONE: + * Run the callback for any event with matching target category. Do not + * do any additional filtering. + * + * @SSAM_EVENT_MASK_TARGET: + * In addition to filtering by target category, only execute the notifier + * callback for events with a target ID matching to the one of the + * registry used for enabling/disabling the event. + * + * @SSAM_EVENT_MASK_INSTANCE: + * In addition to filtering by target category, only execute the notifier + * callback for events with an instance ID matching to the instance ID + * used when enabling the event. + * + * @SSAM_EVENT_MASK_STRICT: + * Do all the filtering above. + */ +enum ssam_event_mask { + SSAM_EVENT_MASK_TARGET = BIT(0), + SSAM_EVENT_MASK_INSTANCE = BIT(1), + + SSAM_EVENT_MASK_NONE = 0, + SSAM_EVENT_MASK_STRICT = + SSAM_EVENT_MASK_TARGET + | SSAM_EVENT_MASK_INSTANCE, +}; + +/** + * SSAM_EVENT_REGISTRY() - Define a new event registry. + * @tc: Target category for the event registry requests. + * @tid: Target ID for the event registry requests. + * @cid_en: Command ID for the event-enable request. + * @cid_dis: Command ID for the event-disable request. + * + * Return: Returns the &struct ssam_event_registry specified by the given + * parameters. + */ +#define SSAM_EVENT_REGISTRY(tc, tid, cid_en, cid_dis) \ + ((struct ssam_event_registry) { \ + .target_category = (tc), \ + .target_id = (tid), \ + .cid_enable = (cid_en), \ + .cid_disable = (cid_dis), \ + }) + +#define SSAM_EVENT_REGISTRY_SAM \ + SSAM_EVENT_REGISTRY(SSAM_SSH_TC_SAM, 0x01, 0x0b, 0x0c) + +#define SSAM_EVENT_REGISTRY_KIP \ + SSAM_EVENT_REGISTRY(SSAM_SSH_TC_KIP, 0x02, 0x27, 0x28) + +#define SSAM_EVENT_REGISTRY_REG \ + SSAM_EVENT_REGISTRY(SSAM_SSH_TC_REG, 0x02, 0x01, 0x02) + +/** + * struct ssam_event_notifier - Notifier block for SSAM events. + * @base: The base notifier block with callback function and priority. + * @event: The event for which this block will receive notifications. + * @event.reg: Registry via which the event will be enabled/disabled. + * @event.id: ID specifying the event. + * @event.mask: Flags determining how events are matched to the notifier. + * @event.flags: Flags used for enabling the event. + */ +struct ssam_event_notifier { + struct ssam_notifier_block base; + + struct { + struct ssam_event_registry reg; + struct ssam_event_id id; + enum ssam_event_mask mask; + u8 flags; + } event; +}; + +int ssam_notifier_register(struct ssam_controller *ctrl, + struct ssam_event_notifier *n); + +int ssam_notifier_unregister(struct ssam_controller *ctrl, + struct ssam_event_notifier *n); + +#endif /* _LINUX_SURFACE_AGGREGATOR_CONTROLLER_H */ diff --git a/include/linux/surface_aggregator/serial_hub.h b/include/linux/surface_aggregator/serial_hub.h new file mode 100644 index 000000000000..64276fbfa1d5 --- /dev/null +++ b/include/linux/surface_aggregator/serial_hub.h @@ -0,0 +1,672 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Surface Serial Hub (SSH) protocol and communication interface. + * + * Lower-level communication layers and SSH protocol definitions for the + * Surface System Aggregator Module (SSAM). Provides the interface for basic + * packet- and request-based communication with the SSAM EC via SSH. + * + * Copyright (C) 2019-2020 Maximilian Luz + */ + +#ifndef _LINUX_SURFACE_AGGREGATOR_SERIAL_HUB_H +#define _LINUX_SURFACE_AGGREGATOR_SERIAL_HUB_H + +#include +#include +#include +#include +#include + + +/* -- Data structures for SAM-over-SSH communication. ----------------------- */ + +/** + * enum ssh_frame_type - Frame types for SSH frames. + * + * @SSH_FRAME_TYPE_DATA_SEQ: + * Indicates a data frame, followed by a payload with the length specified + * in the ``struct ssh_frame.len`` field. This frame is sequenced, meaning + * that an ACK is required. + * + * @SSH_FRAME_TYPE_DATA_NSQ: + * Same as %SSH_FRAME_TYPE_DATA_SEQ, but unsequenced, meaning that the + * message does not have to be ACKed. + * + * @SSH_FRAME_TYPE_ACK: + * Indicates an ACK message. + * + * @SSH_FRAME_TYPE_NAK: + * Indicates an error response for previously sent frame. In general, this + * means that the frame and/or payload is malformed, e.g. a CRC is wrong. + * For command-type payloads, this can also mean that the command is + * invalid. + */ +enum ssh_frame_type { + SSH_FRAME_TYPE_DATA_SEQ = 0x80, + SSH_FRAME_TYPE_DATA_NSQ = 0x00, + SSH_FRAME_TYPE_ACK = 0x40, + SSH_FRAME_TYPE_NAK = 0x04, +}; + +/** + * struct ssh_frame - SSH communication frame. + * @type: The type of the frame. See &enum ssh_frame_type. + * @len: The length of the frame payload directly following the CRC for this + * frame. Does not include the final CRC for that payload. + * @seq: The sequence number for this message/exchange. + */ +struct ssh_frame { + u8 type; + __le16 len; + u8 seq; +} __packed; + +static_assert(sizeof(struct ssh_frame) == 4); + +/* + * SSH_FRAME_MAX_PAYLOAD_SIZE - Maximum SSH frame payload length in bytes. + * + * This is the physical maximum length of the protocol. Implementations may + * set a more constrained limit. + */ +#define SSH_FRAME_MAX_PAYLOAD_SIZE U16_MAX + +/** + * enum ssh_payload_type - Type indicator for the SSH payload. + * @SSH_PLD_TYPE_CMD: The payload is a command structure with optional command + * payload. + */ +enum ssh_payload_type { + SSH_PLD_TYPE_CMD = 0x80, +}; + +/** + * struct ssh_command - Payload of a command-type frame. + * @type: The type of the payload. See &enum ssh_payload_type. Should be + * SSH_PLD_TYPE_CMD for this struct. + * @tc: Command target category. + * @tid_out: Output target ID. Should be zero if this an incoming (EC to host) + * message. + * @tid_in: Input target ID. Should be zero if this is an outgoing (host to + * EC) message. + * @iid: Instance ID. + * @rqid: Request ID. Used to match requests with responses and differentiate + * between responses and events. + * @cid: Command ID. + */ +struct ssh_command { + u8 type; + u8 tc; + u8 tid_out; + u8 tid_in; + u8 iid; + __le16 rqid; + u8 cid; +} __packed; + +static_assert(sizeof(struct ssh_command) == 8); + +/* + * SSH_COMMAND_MAX_PAYLOAD_SIZE - Maximum SSH command payload length in bytes. + * + * This is the physical maximum length of the protocol. Implementations may + * set a more constrained limit. + */ +#define SSH_COMMAND_MAX_PAYLOAD_SIZE \ + (SSH_FRAME_MAX_PAYLOAD_SIZE - sizeof(struct ssh_command)) + +/* + * SSH_MSG_LEN_BASE - Base-length of a SSH message. + * + * This is the minimum number of bytes required to form a message. The actual + * message length is SSH_MSG_LEN_BASE plus the length of the frame payload. + */ +#define SSH_MSG_LEN_BASE (sizeof(struct ssh_frame) + 3ull * sizeof(u16)) + +/* + * SSH_MSG_LEN_CTRL - Length of a SSH control message. + * + * This is the length of a SSH control message, which is equal to a SSH + * message without any payload. + */ +#define SSH_MSG_LEN_CTRL SSH_MSG_LEN_BASE + +/** + * SSH_MESSAGE_LENGTH() - Compute length of SSH message. + * @payload_size: Length of the payload inside the SSH frame. + * + * Return: Returns the length of a SSH message with payload of specified size. + */ +#define SSH_MESSAGE_LENGTH(payload_size) (SSH_MSG_LEN_BASE + (payload_size)) + +/** + * SSH_COMMAND_MESSAGE_LENGTH() - Compute length of SSH command message. + * @payload_size: Length of the command payload. + * + * Return: Returns the length of a SSH command message with command payload of + * specified size. + */ +#define SSH_COMMAND_MESSAGE_LENGTH(payload_size) \ + SSH_MESSAGE_LENGTH(sizeof(struct ssh_command) + (payload_size)) + +/** + * SSH_MSGOFFSET_FRAME() - Compute offset in SSH message to specified field in + * frame. + * @field: The field for which the offset should be computed. + * + * Return: Returns the offset of the specified &struct ssh_frame field in the + * raw SSH message data as. Takes SYN bytes (u16) preceding the frame into + * account. + */ +#define SSH_MSGOFFSET_FRAME(field) \ + (sizeof(u16) + offsetof(struct ssh_frame, field)) + +/** + * SSH_MSGOFFSET_COMMAND() - Compute offset in SSH message to specified field + * in command. + * @field: The field for which the offset should be computed. + * + * Return: Returns the offset of the specified &struct ssh_command field in + * the raw SSH message data. Takes SYN bytes (u16) preceding the frame and the + * frame CRC (u16) between frame and command into account. + */ +#define SSH_MSGOFFSET_COMMAND(field) \ + (2ull * sizeof(u16) + sizeof(struct ssh_frame) \ + + offsetof(struct ssh_command, field)) + +/* + * SSH_MSG_SYN - SSH message synchronization (SYN) bytes as u16. + */ +#define SSH_MSG_SYN ((u16)0x55aa) + +/** + * ssh_crc() - Compute CRC for SSH messages. + * @buf: The pointer pointing to the data for which the CRC should be computed. + * @len: The length of the data for which the CRC should be computed. + * + * Return: Returns the CRC computed on the provided data, as used for SSH + * messages. + */ +static inline u16 ssh_crc(const u8 *buf, size_t len) +{ + return crc_ccitt_false(0xffff, buf, len); +} + +/* + * SSH_NUM_EVENTS - The number of reserved event IDs. + * + * The number of reserved event IDs, used for registering an SSH event + * handler. Valid event IDs are numbers below or equal to this value, with + * exception of zero, which is not an event ID. Thus, this is also the + * absolute maximum number of event handlers that can be registered. + */ +#define SSH_NUM_EVENTS 34 + +/* + * SSH_NUM_TARGETS - The number of communication targets used in the protocol. + */ +#define SSH_NUM_TARGETS 2 + +/** + * ssh_rqid_next_valid() - Return the next valid request ID. + * @rqid: The current request ID. + * + * Return: Returns the next valid request ID, following the current request ID + * provided to this function. This function skips any request IDs reserved for + * events. + */ +static inline u16 ssh_rqid_next_valid(u16 rqid) +{ + return rqid > 0 ? rqid + 1u : rqid + SSH_NUM_EVENTS + 1u; +} + +/** + * ssh_rqid_to_event() - Convert request ID to its corresponding event ID. + * @rqid: The request ID to convert. + */ +static inline u16 ssh_rqid_to_event(u16 rqid) +{ + return rqid - 1u; +} + +/** + * ssh_rqid_is_event() - Check if given request ID is a valid event ID. + * @rqid: The request ID to check. + */ +static inline bool ssh_rqid_is_event(u16 rqid) +{ + return ssh_rqid_to_event(rqid) < SSH_NUM_EVENTS; +} + +/** + * ssh_tc_to_rqid() - Convert target category to its corresponding request ID. + * @tc: The target category to convert. + */ +static inline u16 ssh_tc_to_rqid(u8 tc) +{ + return tc; +} + +/** + * ssh_tid_to_index() - Convert target ID to its corresponding target index. + * @tid: The target ID to convert. + */ +static inline u8 ssh_tid_to_index(u8 tid) +{ + return tid - 1u; +} + +/** + * ssh_tid_is_valid() - Check if target ID is valid/supported. + * @tid: The target ID to check. + */ +static inline bool ssh_tid_is_valid(u8 tid) +{ + return ssh_tid_to_index(tid) < SSH_NUM_TARGETS; +} + +/** + * struct ssam_span - Reference to a buffer region. + * @ptr: Pointer to the buffer region. + * @len: Length of the buffer region. + * + * A reference to a (non-owned) buffer segment, consisting of pointer and + * length. Use of this struct indicates non-owned data, i.e. data of which the + * life-time is managed (i.e. it is allocated/freed) via another pointer. + */ +struct ssam_span { + u8 *ptr; + size_t len; +}; + +/* + * Known SSH/EC target categories. + * + * List of currently known target category values; "Known" as in we know they + * exist and are valid on at least some device/model. Detailed functionality + * or the full category name is only known for some of these categories and + * is detailed in the respective comment below. + * + * These values and abbreviations have been extracted from strings inside the + * Windows driver. + */ +enum ssam_ssh_tc { + /* Category 0x00 is invalid for EC use. */ + SSAM_SSH_TC_SAM = 0x01, /* Generic system functionality, real-time clock. */ + SSAM_SSH_TC_BAT = 0x02, /* Battery/power subsystem. */ + SSAM_SSH_TC_TMP = 0x03, /* Thermal subsystem. */ + SSAM_SSH_TC_PMC = 0x04, + SSAM_SSH_TC_FAN = 0x05, + SSAM_SSH_TC_PoM = 0x06, + SSAM_SSH_TC_DBG = 0x07, + SSAM_SSH_TC_KBD = 0x08, /* Legacy keyboard (Laptop 1/2). */ + SSAM_SSH_TC_FWU = 0x09, + SSAM_SSH_TC_UNI = 0x0a, + SSAM_SSH_TC_LPC = 0x0b, + SSAM_SSH_TC_TCL = 0x0c, + SSAM_SSH_TC_SFL = 0x0d, + SSAM_SSH_TC_KIP = 0x0e, + SSAM_SSH_TC_EXT = 0x0f, + SSAM_SSH_TC_BLD = 0x10, + SSAM_SSH_TC_BAS = 0x11, /* Detachment system (Surface Book 2/3). */ + SSAM_SSH_TC_SEN = 0x12, + SSAM_SSH_TC_SRQ = 0x13, + SSAM_SSH_TC_MCU = 0x14, + SSAM_SSH_TC_HID = 0x15, /* Generic HID input subsystem. */ + SSAM_SSH_TC_TCH = 0x16, + SSAM_SSH_TC_BKL = 0x17, + SSAM_SSH_TC_TAM = 0x18, + SSAM_SSH_TC_ACC = 0x19, + SSAM_SSH_TC_UFI = 0x1a, + SSAM_SSH_TC_USC = 0x1b, + SSAM_SSH_TC_PEN = 0x1c, + SSAM_SSH_TC_VID = 0x1d, + SSAM_SSH_TC_AUD = 0x1e, + SSAM_SSH_TC_SMC = 0x1f, + SSAM_SSH_TC_KPD = 0x20, + SSAM_SSH_TC_REG = 0x21, /* Extended event registry. */ +}; + + +/* -- Packet transport layer (ptl). ----------------------------------------- */ + +/** + * enum ssh_packet_base_priority - Base priorities for &struct ssh_packet. + * @SSH_PACKET_PRIORITY_FLUSH: Base priority for flush packets. + * @SSH_PACKET_PRIORITY_DATA: Base priority for normal data packets. + * @SSH_PACKET_PRIORITY_NAK: Base priority for NAK packets. + * @SSH_PACKET_PRIORITY_ACK: Base priority for ACK packets. + */ +enum ssh_packet_base_priority { + SSH_PACKET_PRIORITY_FLUSH = 0, /* same as DATA to sequence flush */ + SSH_PACKET_PRIORITY_DATA = 0, + SSH_PACKET_PRIORITY_NAK = 1, + SSH_PACKET_PRIORITY_ACK = 2, +}; + +/* + * Same as SSH_PACKET_PRIORITY() below, only with actual values. + */ +#define __SSH_PACKET_PRIORITY(base, try) \ + (((base) << 4) | ((try) & 0x0f)) + +/** + * SSH_PACKET_PRIORITY() - Compute packet priority from base priority and + * number of tries. + * @base: The base priority as suffix of &enum ssh_packet_base_priority, e.g. + * ``FLUSH``, ``DATA``, ``ACK``, or ``NAK``. + * @try: The number of tries (must be less than 16). + * + * Compute the combined packet priority. The combined priority is dominated by + * the base priority, whereas the number of (re-)tries decides the precedence + * of packets with the same base priority, giving higher priority to packets + * that already have more tries. + * + * Return: Returns the computed priority as value fitting inside a &u8. A + * higher number means a higher priority. + */ +#define SSH_PACKET_PRIORITY(base, try) \ + __SSH_PACKET_PRIORITY(SSH_PACKET_PRIORITY_##base, (try)) + +/** + * ssh_packet_priority_get_try() - Get number of tries from packet priority. + * @priority: The packet priority. + * + * Return: Returns the number of tries encoded in the specified packet + * priority. + */ +static inline u8 ssh_packet_priority_get_try(u8 priority) +{ + return priority & 0x0f; +} + +/** + * ssh_packet_priority_get_base - Get base priority from packet priority. + * @priority: The packet priority. + * + * Return: Returns the base priority encoded in the given packet priority. + */ +static inline u8 ssh_packet_priority_get_base(u8 priority) +{ + return (priority & 0xf0) >> 4; +} + +enum ssh_packet_flags { + /* state flags */ + SSH_PACKET_SF_LOCKED_BIT, + SSH_PACKET_SF_QUEUED_BIT, + SSH_PACKET_SF_PENDING_BIT, + SSH_PACKET_SF_TRANSMITTING_BIT, + SSH_PACKET_SF_TRANSMITTED_BIT, + SSH_PACKET_SF_ACKED_BIT, + SSH_PACKET_SF_CANCELED_BIT, + SSH_PACKET_SF_COMPLETED_BIT, + + /* type flags */ + SSH_PACKET_TY_FLUSH_BIT, + SSH_PACKET_TY_SEQUENCED_BIT, + SSH_PACKET_TY_BLOCKING_BIT, + + /* mask for state flags */ + SSH_PACKET_FLAGS_SF_MASK = + BIT(SSH_PACKET_SF_LOCKED_BIT) + | BIT(SSH_PACKET_SF_QUEUED_BIT) + | BIT(SSH_PACKET_SF_PENDING_BIT) + | BIT(SSH_PACKET_SF_TRANSMITTING_BIT) + | BIT(SSH_PACKET_SF_TRANSMITTED_BIT) + | BIT(SSH_PACKET_SF_ACKED_BIT) + | BIT(SSH_PACKET_SF_CANCELED_BIT) + | BIT(SSH_PACKET_SF_COMPLETED_BIT), + + /* mask for type flags */ + SSH_PACKET_FLAGS_TY_MASK = + BIT(SSH_PACKET_TY_FLUSH_BIT) + | BIT(SSH_PACKET_TY_SEQUENCED_BIT) + | BIT(SSH_PACKET_TY_BLOCKING_BIT), +}; + +struct ssh_ptl; +struct ssh_packet; + +/** + * struct ssh_packet_ops - Callback operations for a SSH packet. + * @release: Function called when the packet reference count reaches zero. + * This callback must be relied upon to ensure that the packet has + * left the transport system(s). + * @complete: Function called when the packet is completed, either with + * success or failure. In case of failure, the reason for the + * failure is indicated by the value of the provided status code + * argument. This value will be zero in case of success. Note that + * a call to this callback does not guarantee that the packet is + * not in use by the transport system any more. + */ +struct ssh_packet_ops { + void (*release)(struct ssh_packet *p); + void (*complete)(struct ssh_packet *p, int status); +}; + +/** + * struct ssh_packet - SSH transport packet. + * @ptl: Pointer to the packet transport layer. May be %NULL if the packet + * (or enclosing request) has not been submitted yet. + * @refcnt: Reference count of the packet. + * @priority: Priority of the packet. Must be computed via + * SSH_PACKET_PRIORITY(). Must only be accessed while holding the + * queue lock after first submission. + * @data: Raw message data. + * @data.len: Length of the raw message data. + * @data.ptr: Pointer to the raw message data buffer. + * @state: State and type flags describing current packet state (dynamic) + * and type (static). See &enum ssh_packet_flags for possible + * options. + * @timestamp: Timestamp specifying when the latest transmission of a + * currently pending packet has been started. May be %KTIME_MAX + * before or in-between transmission attempts. Used for the packet + * timeout implementation. Must only be accessed while holding the + * pending lock after first submission. + * @queue_node: The list node for the packet queue. + * @pending_node: The list node for the set of pending packets. + * @ops: Packet operations. + */ +struct ssh_packet { + struct ssh_ptl *ptl; + struct kref refcnt; + + u8 priority; + + struct { + size_t len; + u8 *ptr; + } data; + + unsigned long state; + ktime_t timestamp; + + struct list_head queue_node; + struct list_head pending_node; + + const struct ssh_packet_ops *ops; +}; + +struct ssh_packet *ssh_packet_get(struct ssh_packet *p); +void ssh_packet_put(struct ssh_packet *p); + +/** + * ssh_packet_set_data() - Set raw message data of packet. + * @p: The packet for which the message data should be set. + * @ptr: Pointer to the memory holding the message data. + * @len: Length of the message data. + * + * Sets the raw message data buffer of the packet to the provided memory. The + * memory is not copied. Instead, the caller is responsible for management + * (i.e. allocation and deallocation) of the memory. The caller must ensure + * that the provided memory is valid and contains a valid SSH message, + * starting from the time of submission of the packet until the ``release`` + * callback has been called. During this time, the memory may not be altered + * in any way. + */ +static inline void ssh_packet_set_data(struct ssh_packet *p, u8 *ptr, size_t len) +{ + p->data.ptr = ptr; + p->data.len = len; +} + + +/* -- Request transport layer (rtl). ---------------------------------------- */ + +enum ssh_request_flags { + /* state flags */ + SSH_REQUEST_SF_LOCKED_BIT, + SSH_REQUEST_SF_QUEUED_BIT, + SSH_REQUEST_SF_PENDING_BIT, + SSH_REQUEST_SF_TRANSMITTING_BIT, + SSH_REQUEST_SF_TRANSMITTED_BIT, + SSH_REQUEST_SF_RSPRCVD_BIT, + SSH_REQUEST_SF_CANCELED_BIT, + SSH_REQUEST_SF_COMPLETED_BIT, + + /* type flags */ + SSH_REQUEST_TY_FLUSH_BIT, + SSH_REQUEST_TY_HAS_RESPONSE_BIT, + + /* mask for state flags */ + SSH_REQUEST_FLAGS_SF_MASK = + BIT(SSH_REQUEST_SF_LOCKED_BIT) + | BIT(SSH_REQUEST_SF_QUEUED_BIT) + | BIT(SSH_REQUEST_SF_PENDING_BIT) + | BIT(SSH_REQUEST_SF_TRANSMITTING_BIT) + | BIT(SSH_REQUEST_SF_TRANSMITTED_BIT) + | BIT(SSH_REQUEST_SF_RSPRCVD_BIT) + | BIT(SSH_REQUEST_SF_CANCELED_BIT) + | BIT(SSH_REQUEST_SF_COMPLETED_BIT), + + /* mask for type flags */ + SSH_REQUEST_FLAGS_TY_MASK = + BIT(SSH_REQUEST_TY_FLUSH_BIT) + | BIT(SSH_REQUEST_TY_HAS_RESPONSE_BIT), +}; + +struct ssh_rtl; +struct ssh_request; + +/** + * struct ssh_request_ops - Callback operations for a SSH request. + * @release: Function called when the request's reference count reaches zero. + * This callback must be relied upon to ensure that the request has + * left the transport systems (both, packet an request systems). + * @complete: Function called when the request is completed, either with + * success or failure. The command data for the request response + * is provided via the &struct ssh_command parameter (``cmd``), + * the command payload of the request response via the &struct + * ssh_span parameter (``data``). + * + * If the request does not have any response or has not been + * completed with success, both ``cmd`` and ``data`` parameters will + * be NULL. If the request response does not have any command + * payload, the ``data`` span will be an empty (zero-length) span. + * + * In case of failure, the reason for the failure is indicated by + * the value of the provided status code argument (``status``). This + * value will be zero in case of success and a regular errno + * otherwise. + * + * Note that a call to this callback does not guarantee that the + * request is not in use by the transport systems any more. + */ +struct ssh_request_ops { + void (*release)(struct ssh_request *rqst); + void (*complete)(struct ssh_request *rqst, + const struct ssh_command *cmd, + const struct ssam_span *data, int status); +}; + +/** + * struct ssh_request - SSH transport request. + * @packet: The underlying SSH transport packet. + * @node: List node for the request queue and pending set. + * @state: State and type flags describing current request state (dynamic) + * and type (static). See &enum ssh_request_flags for possible + * options. + * @timestamp: Timestamp specifying when we start waiting on the response of + * the request. This is set once the underlying packet has been + * completed and may be %KTIME_MAX before that, or when the request + * does not expect a response. Used for the request timeout + * implementation. + * @ops: Request Operations. + */ +struct ssh_request { + struct ssh_packet packet; + struct list_head node; + + unsigned long state; + ktime_t timestamp; + + const struct ssh_request_ops *ops; +}; + +/** + * to_ssh_request() - Cast a SSH packet to its enclosing SSH request. + * @p: The packet to cast. + * + * Casts the given &struct ssh_packet to its enclosing &struct ssh_request. + * The caller is responsible for making sure that the packet is actually + * wrapped in a &struct ssh_request. + * + * Return: Returns the &struct ssh_request wrapping the provided packet. + */ +static inline struct ssh_request *to_ssh_request(struct ssh_packet *p) +{ + return container_of(p, struct ssh_request, packet); +} + +/** + * ssh_request_get() - Increment reference count of request. + * @r: The request to increment the reference count of. + * + * Increments the reference count of the given request by incrementing the + * reference count of the underlying &struct ssh_packet, enclosed in it. + * + * See also ssh_request_put(), ssh_packet_get(). + * + * Return: Returns the request provided as input. + */ +static inline struct ssh_request *ssh_request_get(struct ssh_request *r) +{ + return r ? to_ssh_request(ssh_packet_get(&r->packet)) : NULL; +} + +/** + * ssh_request_put() - Decrement reference count of request. + * @r: The request to decrement the reference count of. + * + * Decrements the reference count of the given request by decrementing the + * reference count of the underlying &struct ssh_packet, enclosed in it. If + * the reference count reaches zero, the ``release`` callback specified in the + * request's &struct ssh_request_ops, i.e. ``r->ops->release``, will be + * called. + * + * See also ssh_request_get(), ssh_packet_put(). + */ +static inline void ssh_request_put(struct ssh_request *r) +{ + if (r) + ssh_packet_put(&r->packet); +} + +/** + * ssh_request_set_data() - Set raw message data of request. + * @r: The request for which the message data should be set. + * @ptr: Pointer to the memory holding the message data. + * @len: Length of the message data. + * + * Sets the raw message data buffer of the underlying packet to the specified + * buffer. Does not copy the actual message data, just sets the buffer pointer + * and length. Refer to ssh_packet_set_data() for more details. + */ +static inline void ssh_request_set_data(struct ssh_request *r, u8 *ptr, size_t len) +{ + ssh_packet_set_data(&r->packet, ptr, len); +} + +#endif /* _LINUX_SURFACE_AGGREGATOR_SERIAL_HUB_H */ -- cgit v1.2.3 From eb0e90a82098d4a48308abb87d2087578a83987f Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Mon, 21 Dec 2020 19:39:56 +0100 Subject: platform/surface: aggregator: Add dedicated bus and device type The Surface Aggregator EC provides varying functionality, depending on the Surface device. To manage this functionality, we use dedicated client devices for each subsystem or virtual device of the EC. While some of these clients are described as standard devices in ACPI and the corresponding client drivers can be implemented as platform drivers in the kernel (making use of the controller API already present), many devices, especially on newer Surface models, cannot be found there. To simplify management of these devices, we introduce a new bus and client device type for the Surface Aggregator subsystem. The new device type takes care of managing the controller reference, essentially guaranteeing its validity for as long as the client device exists, thus alleviating the need to manually establish device links for that purpose in the client driver (as has to be done with the platform devices). Signed-off-by: Maximilian Luz Reviewed-by: Hans de Goede Link: https://lore.kernel.org/r/20201221183959.1186143-7-luzmaximilian@gmail.com Signed-off-by: Hans de Goede --- drivers/platform/surface/aggregator/Kconfig | 12 + drivers/platform/surface/aggregator/Makefile | 4 + drivers/platform/surface/aggregator/bus.c | 415 ++++++++++++++++++++++++++ drivers/platform/surface/aggregator/bus.h | 27 ++ drivers/platform/surface/aggregator/core.c | 12 + include/linux/mod_devicetable.h | 18 ++ include/linux/surface_aggregator/device.h | 423 +++++++++++++++++++++++++++ scripts/mod/devicetable-offsets.c | 8 + scripts/mod/file2alias.c | 23 ++ 9 files changed, 942 insertions(+) create mode 100644 drivers/platform/surface/aggregator/bus.c create mode 100644 drivers/platform/surface/aggregator/bus.h create mode 100644 include/linux/surface_aggregator/device.h (limited to 'include') diff --git a/drivers/platform/surface/aggregator/Kconfig b/drivers/platform/surface/aggregator/Kconfig index e417bac67088..3aaeea9f0433 100644 --- a/drivers/platform/surface/aggregator/Kconfig +++ b/drivers/platform/surface/aggregator/Kconfig @@ -41,6 +41,18 @@ menuconfig SURFACE_AGGREGATOR module, y if you want to build it into the kernel and n if you don't want it at all. +config SURFACE_AGGREGATOR_BUS + bool "Surface System Aggregator Module Bus" + depends on SURFACE_AGGREGATOR + default y + help + Expands the Surface System Aggregator Module (SSAM) core driver by + providing a dedicated bus and client-device type. + + This bus and device type are intended to provide and simplify support + for non-platform and non-ACPI SSAM devices, i.e. SSAM devices that are + not auto-detectable via the conventional means (e.g. ACPI). + config SURFACE_AGGREGATOR_ERROR_INJECTION bool "Surface System Aggregator Module Error Injection Capabilities" depends on SURFACE_AGGREGATOR diff --git a/drivers/platform/surface/aggregator/Makefile b/drivers/platform/surface/aggregator/Makefile index b8b24c8ec310..c112e2c7112b 100644 --- a/drivers/platform/surface/aggregator/Makefile +++ b/drivers/platform/surface/aggregator/Makefile @@ -11,3 +11,7 @@ surface_aggregator-objs += ssh_parser.o surface_aggregator-objs += ssh_packet_layer.o surface_aggregator-objs += ssh_request_layer.o surface_aggregator-objs += controller.o + +ifeq ($(CONFIG_SURFACE_AGGREGATOR_BUS),y) +surface_aggregator-objs += bus.o +endif diff --git a/drivers/platform/surface/aggregator/bus.c b/drivers/platform/surface/aggregator/bus.c new file mode 100644 index 000000000000..a9b660af0917 --- /dev/null +++ b/drivers/platform/surface/aggregator/bus.c @@ -0,0 +1,415 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Surface System Aggregator Module bus and device integration. + * + * Copyright (C) 2019-2020 Maximilian Luz + */ + +#include +#include + +#include +#include + +#include "bus.h" +#include "controller.h" + +static ssize_t modalias_show(struct device *dev, struct device_attribute *attr, + char *buf) +{ + struct ssam_device *sdev = to_ssam_device(dev); + + return sysfs_emit(buf, "ssam:d%02Xc%02Xt%02Xi%02Xf%02X\n", + sdev->uid.domain, sdev->uid.category, sdev->uid.target, + sdev->uid.instance, sdev->uid.function); +} +static DEVICE_ATTR_RO(modalias); + +static struct attribute *ssam_device_attrs[] = { + &dev_attr_modalias.attr, + NULL, +}; +ATTRIBUTE_GROUPS(ssam_device); + +static int ssam_device_uevent(struct device *dev, struct kobj_uevent_env *env) +{ + struct ssam_device *sdev = to_ssam_device(dev); + + return add_uevent_var(env, "MODALIAS=ssam:d%02Xc%02Xt%02Xi%02Xf%02X", + sdev->uid.domain, sdev->uid.category, + sdev->uid.target, sdev->uid.instance, + sdev->uid.function); +} + +static void ssam_device_release(struct device *dev) +{ + struct ssam_device *sdev = to_ssam_device(dev); + + ssam_controller_put(sdev->ctrl); + kfree(sdev); +} + +const struct device_type ssam_device_type = { + .name = "surface_aggregator_device", + .groups = ssam_device_groups, + .uevent = ssam_device_uevent, + .release = ssam_device_release, +}; +EXPORT_SYMBOL_GPL(ssam_device_type); + +/** + * ssam_device_alloc() - Allocate and initialize a SSAM client device. + * @ctrl: The controller under which the device should be added. + * @uid: The UID of the device to be added. + * + * Allocates and initializes a new client device. The parent of the device + * will be set to the controller device and the name will be set based on the + * UID. Note that the device still has to be added via ssam_device_add(). + * Refer to that function for more details. + * + * Return: Returns the newly allocated and initialized SSAM client device, or + * %NULL if it could not be allocated. + */ +struct ssam_device *ssam_device_alloc(struct ssam_controller *ctrl, + struct ssam_device_uid uid) +{ + struct ssam_device *sdev; + + sdev = kzalloc(sizeof(*sdev), GFP_KERNEL); + if (!sdev) + return NULL; + + device_initialize(&sdev->dev); + sdev->dev.bus = &ssam_bus_type; + sdev->dev.type = &ssam_device_type; + sdev->dev.parent = ssam_controller_device(ctrl); + sdev->ctrl = ssam_controller_get(ctrl); + sdev->uid = uid; + + dev_set_name(&sdev->dev, "%02x:%02x:%02x:%02x:%02x", + sdev->uid.domain, sdev->uid.category, sdev->uid.target, + sdev->uid.instance, sdev->uid.function); + + return sdev; +} +EXPORT_SYMBOL_GPL(ssam_device_alloc); + +/** + * ssam_device_add() - Add a SSAM client device. + * @sdev: The SSAM client device to be added. + * + * Added client devices must be guaranteed to always have a valid and active + * controller. Thus, this function will fail with %-ENODEV if the controller + * of the device has not been initialized yet, has been suspended, or has been + * shut down. + * + * The caller of this function should ensure that the corresponding call to + * ssam_device_remove() is issued before the controller is shut down. If the + * added device is a direct child of the controller device (default), it will + * be automatically removed when the controller is shut down. + * + * By default, the controller device will become the parent of the newly + * created client device. The parent may be changed before ssam_device_add is + * called, but care must be taken that a) the correct suspend/resume ordering + * is guaranteed and b) the client device does not outlive the controller, + * i.e. that the device is removed before the controller is being shut down. + * In case these guarantees have to be manually enforced, please refer to the + * ssam_client_link() and ssam_client_bind() functions, which are intended to + * set up device-links for this purpose. + * + * Return: Returns zero on success, a negative error code on failure. + */ +int ssam_device_add(struct ssam_device *sdev) +{ + int status; + + /* + * Ensure that we can only add new devices to a controller if it has + * been started and is not going away soon. This works in combination + * with ssam_controller_remove_clients to ensure driver presence for the + * controller device, i.e. it ensures that the controller (sdev->ctrl) + * is always valid and can be used for requests as long as the client + * device we add here is registered as child under it. This essentially + * guarantees that the client driver can always expect the preconditions + * for functions like ssam_request_sync (controller has to be started + * and is not suspended) to hold and thus does not have to check for + * them. + * + * Note that for this to work, the controller has to be a parent device. + * If it is not a direct parent, care has to be taken that the device is + * removed via ssam_device_remove(), as device_unregister does not + * remove child devices recursively. + */ + ssam_controller_statelock(sdev->ctrl); + + if (sdev->ctrl->state != SSAM_CONTROLLER_STARTED) { + ssam_controller_stateunlock(sdev->ctrl); + return -ENODEV; + } + + status = device_add(&sdev->dev); + + ssam_controller_stateunlock(sdev->ctrl); + return status; +} +EXPORT_SYMBOL_GPL(ssam_device_add); + +/** + * ssam_device_remove() - Remove a SSAM client device. + * @sdev: The device to remove. + * + * Removes and unregisters the provided SSAM client device. + */ +void ssam_device_remove(struct ssam_device *sdev) +{ + device_unregister(&sdev->dev); +} +EXPORT_SYMBOL_GPL(ssam_device_remove); + +/** + * ssam_device_id_compatible() - Check if a device ID matches a UID. + * @id: The device ID as potential match. + * @uid: The device UID matching against. + * + * Check if the given ID is a match for the given UID, i.e. if a device with + * the provided UID is compatible to the given ID following the match rules + * described in its &ssam_device_id.match_flags member. + * + * Return: Returns %true if the given UID is compatible to the match rule + * described by the given ID, %false otherwise. + */ +static bool ssam_device_id_compatible(const struct ssam_device_id *id, + struct ssam_device_uid uid) +{ + if (id->domain != uid.domain || id->category != uid.category) + return false; + + if ((id->match_flags & SSAM_MATCH_TARGET) && id->target != uid.target) + return false; + + if ((id->match_flags & SSAM_MATCH_INSTANCE) && id->instance != uid.instance) + return false; + + if ((id->match_flags & SSAM_MATCH_FUNCTION) && id->function != uid.function) + return false; + + return true; +} + +/** + * ssam_device_id_is_null() - Check if a device ID is null. + * @id: The device ID to check. + * + * Check if a given device ID is null, i.e. all zeros. Used to check for the + * end of ``MODULE_DEVICE_TABLE(ssam, ...)`` or similar lists. + * + * Return: Returns %true if the given ID represents a null ID, %false + * otherwise. + */ +static bool ssam_device_id_is_null(const struct ssam_device_id *id) +{ + return id->match_flags == 0 && + id->domain == 0 && + id->category == 0 && + id->target == 0 && + id->instance == 0 && + id->function == 0 && + id->driver_data == 0; +} + +/** + * ssam_device_id_match() - Find the matching ID table entry for the given UID. + * @table: The table to search in. + * @uid: The UID to matched against the individual table entries. + * + * Find the first match for the provided device UID in the provided ID table + * and return it. Returns %NULL if no match could be found. + */ +const struct ssam_device_id *ssam_device_id_match(const struct ssam_device_id *table, + const struct ssam_device_uid uid) +{ + const struct ssam_device_id *id; + + for (id = table; !ssam_device_id_is_null(id); ++id) + if (ssam_device_id_compatible(id, uid)) + return id; + + return NULL; +} +EXPORT_SYMBOL_GPL(ssam_device_id_match); + +/** + * ssam_device_get_match() - Find and return the ID matching the device in the + * ID table of the bound driver. + * @dev: The device for which to get the matching ID table entry. + * + * Find the fist match for the UID of the device in the ID table of the + * currently bound driver and return it. Returns %NULL if the device does not + * have a driver bound to it, the driver does not have match_table (i.e. it is + * %NULL), or there is no match in the driver's match_table. + * + * This function essentially calls ssam_device_id_match() with the ID table of + * the bound device driver and the UID of the device. + * + * Return: Returns the first match for the UID of the device in the device + * driver's match table, or %NULL if no such match could be found. + */ +const struct ssam_device_id *ssam_device_get_match(const struct ssam_device *dev) +{ + const struct ssam_device_driver *sdrv; + + sdrv = to_ssam_device_driver(dev->dev.driver); + if (!sdrv) + return NULL; + + if (!sdrv->match_table) + return NULL; + + return ssam_device_id_match(sdrv->match_table, dev->uid); +} +EXPORT_SYMBOL_GPL(ssam_device_get_match); + +/** + * ssam_device_get_match_data() - Find the ID matching the device in the + * ID table of the bound driver and return its ``driver_data`` member. + * @dev: The device for which to get the match data. + * + * Find the fist match for the UID of the device in the ID table of the + * corresponding driver and return its driver_data. Returns %NULL if the + * device does not have a driver bound to it, the driver does not have + * match_table (i.e. it is %NULL), there is no match in the driver's + * match_table, or the match does not have any driver_data. + * + * This function essentially calls ssam_device_get_match() and, if any match + * could be found, returns its ``struct ssam_device_id.driver_data`` member. + * + * Return: Returns the driver data associated with the first match for the UID + * of the device in the device driver's match table, or %NULL if no such match + * could be found. + */ +const void *ssam_device_get_match_data(const struct ssam_device *dev) +{ + const struct ssam_device_id *id; + + id = ssam_device_get_match(dev); + if (!id) + return NULL; + + return (const void *)id->driver_data; +} +EXPORT_SYMBOL_GPL(ssam_device_get_match_data); + +static int ssam_bus_match(struct device *dev, struct device_driver *drv) +{ + struct ssam_device_driver *sdrv = to_ssam_device_driver(drv); + struct ssam_device *sdev = to_ssam_device(dev); + + if (!is_ssam_device(dev)) + return 0; + + return !!ssam_device_id_match(sdrv->match_table, sdev->uid); +} + +static int ssam_bus_probe(struct device *dev) +{ + return to_ssam_device_driver(dev->driver) + ->probe(to_ssam_device(dev)); +} + +static int ssam_bus_remove(struct device *dev) +{ + struct ssam_device_driver *sdrv = to_ssam_device_driver(dev->driver); + + if (sdrv->remove) + sdrv->remove(to_ssam_device(dev)); + + return 0; +} + +struct bus_type ssam_bus_type = { + .name = "surface_aggregator", + .match = ssam_bus_match, + .probe = ssam_bus_probe, + .remove = ssam_bus_remove, +}; +EXPORT_SYMBOL_GPL(ssam_bus_type); + +/** + * __ssam_device_driver_register() - Register a SSAM client device driver. + * @sdrv: The driver to register. + * @owner: The module owning the provided driver. + * + * Please refer to the ssam_device_driver_register() macro for the normal way + * to register a driver from inside its owning module. + */ +int __ssam_device_driver_register(struct ssam_device_driver *sdrv, + struct module *owner) +{ + sdrv->driver.owner = owner; + sdrv->driver.bus = &ssam_bus_type; + + /* force drivers to async probe so I/O is possible in probe */ + sdrv->driver.probe_type = PROBE_PREFER_ASYNCHRONOUS; + + return driver_register(&sdrv->driver); +} +EXPORT_SYMBOL_GPL(__ssam_device_driver_register); + +/** + * ssam_device_driver_unregister - Unregister a SSAM device driver. + * @sdrv: The driver to unregister. + */ +void ssam_device_driver_unregister(struct ssam_device_driver *sdrv) +{ + driver_unregister(&sdrv->driver); +} +EXPORT_SYMBOL_GPL(ssam_device_driver_unregister); + +static int ssam_remove_device(struct device *dev, void *_data) +{ + struct ssam_device *sdev = to_ssam_device(dev); + + if (is_ssam_device(dev)) + ssam_device_remove(sdev); + + return 0; +} + +/** + * ssam_controller_remove_clients() - Remove SSAM client devices registered as + * direct children under the given controller. + * @ctrl: The controller to remove all direct clients for. + * + * Remove all SSAM client devices registered as direct children under the + * given controller. Note that this only accounts for direct children of the + * controller device. This does not take care of any client devices where the + * parent device has been manually set before calling ssam_device_add. Refer + * to ssam_device_add()/ssam_device_remove() for more details on those cases. + * + * To avoid new devices being added in parallel to this call, the main + * controller lock (not statelock) must be held during this (and if + * necessary, any subsequent deinitialization) call. + */ +void ssam_controller_remove_clients(struct ssam_controller *ctrl) +{ + struct device *dev; + + dev = ssam_controller_device(ctrl); + device_for_each_child_reverse(dev, NULL, ssam_remove_device); +} + +/** + * ssam_bus_register() - Register and set-up the SSAM client device bus. + */ +int ssam_bus_register(void) +{ + return bus_register(&ssam_bus_type); +} + +/** + * ssam_bus_unregister() - Unregister the SSAM client device bus. + */ +void ssam_bus_unregister(void) +{ + return bus_unregister(&ssam_bus_type); +} diff --git a/drivers/platform/surface/aggregator/bus.h b/drivers/platform/surface/aggregator/bus.h new file mode 100644 index 000000000000..7712baaed6a5 --- /dev/null +++ b/drivers/platform/surface/aggregator/bus.h @@ -0,0 +1,27 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Surface System Aggregator Module bus and device integration. + * + * Copyright (C) 2019-2020 Maximilian Luz + */ + +#ifndef _SURFACE_AGGREGATOR_BUS_H +#define _SURFACE_AGGREGATOR_BUS_H + +#include + +#ifdef CONFIG_SURFACE_AGGREGATOR_BUS + +void ssam_controller_remove_clients(struct ssam_controller *ctrl); + +int ssam_bus_register(void); +void ssam_bus_unregister(void); + +#else /* CONFIG_SURFACE_AGGREGATOR_BUS */ + +static inline void ssam_controller_remove_clients(struct ssam_controller *ctrl) {} +static inline int ssam_bus_register(void) { return 0; } +static inline void ssam_bus_unregister(void) {} + +#endif /* CONFIG_SURFACE_AGGREGATOR_BUS */ +#endif /* _SURFACE_AGGREGATOR_BUS_H */ diff --git a/drivers/platform/surface/aggregator/core.c b/drivers/platform/surface/aggregator/core.c index b6a9dea53592..8dc2c267bcd6 100644 --- a/drivers/platform/surface/aggregator/core.c +++ b/drivers/platform/surface/aggregator/core.c @@ -22,6 +22,8 @@ #include #include + +#include "bus.h" #include "controller.h" #define CREATE_TRACE_POINTS @@ -739,6 +741,9 @@ static void ssam_serial_hub_remove(struct serdev_device *serdev) sysfs_remove_group(&serdev->dev.kobj, &ssam_sam_group); ssam_controller_lock(ctrl); + /* Remove all client devices. */ + ssam_controller_remove_clients(ctrl); + /* Act as if suspending to silence events. */ status = ssam_ctrl_notif_display_off(ctrl); if (status) { @@ -791,6 +796,10 @@ static int __init ssam_core_init(void) { int status; + status = ssam_bus_register(); + if (status) + goto err_bus; + status = ssh_ctrl_packet_cache_init(); if (status) goto err_cpkg; @@ -810,6 +819,8 @@ err_register: err_evitem: ssh_ctrl_packet_cache_destroy(); err_cpkg: + ssam_bus_unregister(); +err_bus: return status; } module_init(ssam_core_init); @@ -819,6 +830,7 @@ static void __exit ssam_core_exit(void) serdev_device_driver_unregister(&ssam_serial_hub); ssam_event_item_cache_destroy(); ssh_ctrl_packet_cache_destroy(); + ssam_bus_unregister(); } module_exit(ssam_core_exit); diff --git a/include/linux/mod_devicetable.h b/include/linux/mod_devicetable.h index c425290b21e2..935060955152 100644 --- a/include/linux/mod_devicetable.h +++ b/include/linux/mod_devicetable.h @@ -846,4 +846,22 @@ struct auxiliary_device_id { kernel_ulong_t driver_data; }; +/* Surface System Aggregator Module */ + +#define SSAM_MATCH_TARGET 0x1 +#define SSAM_MATCH_INSTANCE 0x2 +#define SSAM_MATCH_FUNCTION 0x4 + +struct ssam_device_id { + __u8 match_flags; + + __u8 domain; + __u8 category; + __u8 target; + __u8 instance; + __u8 function; + + kernel_ulong_t driver_data; +}; + #endif /* LINUX_MOD_DEVICETABLE_H */ diff --git a/include/linux/surface_aggregator/device.h b/include/linux/surface_aggregator/device.h new file mode 100644 index 000000000000..02f3e06c0a60 --- /dev/null +++ b/include/linux/surface_aggregator/device.h @@ -0,0 +1,423 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Surface System Aggregator Module (SSAM) bus and client-device subsystem. + * + * Main interface for the surface-aggregator bus, surface-aggregator client + * devices, and respective drivers building on top of the SSAM controller. + * Provides support for non-platform/non-ACPI SSAM clients via dedicated + * subsystem. + * + * Copyright (C) 2019-2020 Maximilian Luz + */ + +#ifndef _LINUX_SURFACE_AGGREGATOR_DEVICE_H +#define _LINUX_SURFACE_AGGREGATOR_DEVICE_H + +#include +#include +#include + +#include + + +/* -- Surface System Aggregator Module bus. --------------------------------- */ + +/** + * enum ssam_device_domain - SAM device domain. + * @SSAM_DOMAIN_VIRTUAL: Virtual device. + * @SSAM_DOMAIN_SERIALHUB: Physical device connected via Surface Serial Hub. + */ +enum ssam_device_domain { + SSAM_DOMAIN_VIRTUAL = 0x00, + SSAM_DOMAIN_SERIALHUB = 0x01, +}; + +/** + * enum ssam_virtual_tc - Target categories for the virtual SAM domain. + * @SSAM_VIRTUAL_TC_HUB: Device hub category. + */ +enum ssam_virtual_tc { + SSAM_VIRTUAL_TC_HUB = 0x00, +}; + +/** + * struct ssam_device_uid - Unique identifier for SSAM device. + * @domain: Domain of the device. + * @category: Target category of the device. + * @target: Target ID of the device. + * @instance: Instance ID of the device. + * @function: Sub-function of the device. This field can be used to split a + * single SAM device into multiple virtual subdevices to separate + * different functionality of that device and allow one driver per + * such functionality. + */ +struct ssam_device_uid { + u8 domain; + u8 category; + u8 target; + u8 instance; + u8 function; +}; + +/* + * Special values for device matching. + * + * These values are intended to be used with SSAM_DEVICE(), SSAM_VDEV(), and + * SSAM_SDEV() exclusively. Specifically, they are used to initialize the + * match_flags member of the device ID structure. Do not use them directly + * with struct ssam_device_id or struct ssam_device_uid. + */ +#define SSAM_ANY_TID 0xffff +#define SSAM_ANY_IID 0xffff +#define SSAM_ANY_FUN 0xffff + +/** + * SSAM_DEVICE() - Initialize a &struct ssam_device_id with the given + * parameters. + * @d: Domain of the device. + * @cat: Target category of the device. + * @tid: Target ID of the device. + * @iid: Instance ID of the device. + * @fun: Sub-function of the device. + * + * Initializes a &struct ssam_device_id with the given parameters. See &struct + * ssam_device_uid for details regarding the parameters. The special values + * %SSAM_ANY_TID, %SSAM_ANY_IID, and %SSAM_ANY_FUN can be used to specify that + * matching should ignore target ID, instance ID, and/or sub-function, + * respectively. This macro initializes the ``match_flags`` field based on the + * given parameters. + * + * Note: The parameters @d and @cat must be valid &u8 values, the parameters + * @tid, @iid, and @fun must be either valid &u8 values or %SSAM_ANY_TID, + * %SSAM_ANY_IID, or %SSAM_ANY_FUN, respectively. Other non-&u8 values are not + * allowed. + */ +#define SSAM_DEVICE(d, cat, tid, iid, fun) \ + .match_flags = (((tid) != SSAM_ANY_TID) ? SSAM_MATCH_TARGET : 0) \ + | (((iid) != SSAM_ANY_IID) ? SSAM_MATCH_INSTANCE : 0) \ + | (((fun) != SSAM_ANY_FUN) ? SSAM_MATCH_FUNCTION : 0), \ + .domain = d, \ + .category = cat, \ + .target = ((tid) != SSAM_ANY_TID) ? (tid) : 0, \ + .instance = ((iid) != SSAM_ANY_IID) ? (iid) : 0, \ + .function = ((fun) != SSAM_ANY_FUN) ? (fun) : 0 \ + +/** + * SSAM_VDEV() - Initialize a &struct ssam_device_id as virtual device with + * the given parameters. + * @cat: Target category of the device. + * @tid: Target ID of the device. + * @iid: Instance ID of the device. + * @fun: Sub-function of the device. + * + * Initializes a &struct ssam_device_id with the given parameters in the + * virtual domain. See &struct ssam_device_uid for details regarding the + * parameters. The special values %SSAM_ANY_TID, %SSAM_ANY_IID, and + * %SSAM_ANY_FUN can be used to specify that matching should ignore target ID, + * instance ID, and/or sub-function, respectively. This macro initializes the + * ``match_flags`` field based on the given parameters. + * + * Note: The parameter @cat must be a valid &u8 value, the parameters @tid, + * @iid, and @fun must be either valid &u8 values or %SSAM_ANY_TID, + * %SSAM_ANY_IID, or %SSAM_ANY_FUN, respectively. Other non-&u8 values are not + * allowed. + */ +#define SSAM_VDEV(cat, tid, iid, fun) \ + SSAM_DEVICE(SSAM_DOMAIN_VIRTUAL, SSAM_VIRTUAL_TC_##cat, tid, iid, fun) + +/** + * SSAM_SDEV() - Initialize a &struct ssam_device_id as physical SSH device + * with the given parameters. + * @cat: Target category of the device. + * @tid: Target ID of the device. + * @iid: Instance ID of the device. + * @fun: Sub-function of the device. + * + * Initializes a &struct ssam_device_id with the given parameters in the SSH + * domain. See &struct ssam_device_uid for details regarding the parameters. + * The special values %SSAM_ANY_TID, %SSAM_ANY_IID, and %SSAM_ANY_FUN can be + * used to specify that matching should ignore target ID, instance ID, and/or + * sub-function, respectively. This macro initializes the ``match_flags`` + * field based on the given parameters. + * + * Note: The parameter @cat must be a valid &u8 value, the parameters @tid, + * @iid, and @fun must be either valid &u8 values or %SSAM_ANY_TID, + * %SSAM_ANY_IID, or %SSAM_ANY_FUN, respectively. Other non-&u8 values are not + * allowed. + */ +#define SSAM_SDEV(cat, tid, iid, fun) \ + SSAM_DEVICE(SSAM_DOMAIN_SERIALHUB, SSAM_SSH_TC_##cat, tid, iid, fun) + +/** + * struct ssam_device - SSAM client device. + * @dev: Driver model representation of the device. + * @ctrl: SSAM controller managing this device. + * @uid: UID identifying the device. + */ +struct ssam_device { + struct device dev; + struct ssam_controller *ctrl; + + struct ssam_device_uid uid; +}; + +/** + * struct ssam_device_driver - SSAM client device driver. + * @driver: Base driver model structure. + * @match_table: Match table specifying which devices the driver should bind to. + * @probe: Called when the driver is being bound to a device. + * @remove: Called when the driver is being unbound from the device. + */ +struct ssam_device_driver { + struct device_driver driver; + + const struct ssam_device_id *match_table; + + int (*probe)(struct ssam_device *sdev); + void (*remove)(struct ssam_device *sdev); +}; + +extern struct bus_type ssam_bus_type; +extern const struct device_type ssam_device_type; + +/** + * is_ssam_device() - Check if the given device is a SSAM client device. + * @d: The device to test the type of. + * + * Return: Returns %true if the specified device is of type &struct + * ssam_device, i.e. the device type points to %ssam_device_type, and %false + * otherwise. + */ +static inline bool is_ssam_device(struct device *d) +{ + return d->type == &ssam_device_type; +} + +/** + * to_ssam_device() - Casts the given device to a SSAM client device. + * @d: The device to cast. + * + * Casts the given &struct device to a &struct ssam_device. The caller has to + * ensure that the given device is actually enclosed in a &struct ssam_device, + * e.g. by calling is_ssam_device(). + * + * Return: Returns a pointer to the &struct ssam_device wrapping the given + * device @d. + */ +static inline struct ssam_device *to_ssam_device(struct device *d) +{ + return container_of(d, struct ssam_device, dev); +} + +/** + * to_ssam_device_driver() - Casts the given device driver to a SSAM client + * device driver. + * @d: The driver to cast. + * + * Casts the given &struct device_driver to a &struct ssam_device_driver. The + * caller has to ensure that the given driver is actually enclosed in a + * &struct ssam_device_driver. + * + * Return: Returns the pointer to the &struct ssam_device_driver wrapping the + * given device driver @d. + */ +static inline +struct ssam_device_driver *to_ssam_device_driver(struct device_driver *d) +{ + return container_of(d, struct ssam_device_driver, driver); +} + +const struct ssam_device_id *ssam_device_id_match(const struct ssam_device_id *table, + const struct ssam_device_uid uid); + +const struct ssam_device_id *ssam_device_get_match(const struct ssam_device *dev); + +const void *ssam_device_get_match_data(const struct ssam_device *dev); + +struct ssam_device *ssam_device_alloc(struct ssam_controller *ctrl, + struct ssam_device_uid uid); + +int ssam_device_add(struct ssam_device *sdev); +void ssam_device_remove(struct ssam_device *sdev); + +/** + * ssam_device_get() - Increment reference count of SSAM client device. + * @sdev: The device to increment the reference count of. + * + * Increments the reference count of the given SSAM client device by + * incrementing the reference count of the enclosed &struct device via + * get_device(). + * + * See ssam_device_put() for the counter-part of this function. + * + * Return: Returns the device provided as input. + */ +static inline struct ssam_device *ssam_device_get(struct ssam_device *sdev) +{ + return sdev ? to_ssam_device(get_device(&sdev->dev)) : NULL; +} + +/** + * ssam_device_put() - Decrement reference count of SSAM client device. + * @sdev: The device to decrement the reference count of. + * + * Decrements the reference count of the given SSAM client device by + * decrementing the reference count of the enclosed &struct device via + * put_device(). + * + * See ssam_device_get() for the counter-part of this function. + */ +static inline void ssam_device_put(struct ssam_device *sdev) +{ + if (sdev) + put_device(&sdev->dev); +} + +/** + * ssam_device_get_drvdata() - Get driver-data of SSAM client device. + * @sdev: The device to get the driver-data from. + * + * Return: Returns the driver-data of the given device, previously set via + * ssam_device_set_drvdata(). + */ +static inline void *ssam_device_get_drvdata(struct ssam_device *sdev) +{ + return dev_get_drvdata(&sdev->dev); +} + +/** + * ssam_device_set_drvdata() - Set driver-data of SSAM client device. + * @sdev: The device to set the driver-data of. + * @data: The data to set the device's driver-data pointer to. + */ +static inline void ssam_device_set_drvdata(struct ssam_device *sdev, void *data) +{ + dev_set_drvdata(&sdev->dev, data); +} + +int __ssam_device_driver_register(struct ssam_device_driver *d, struct module *o); +void ssam_device_driver_unregister(struct ssam_device_driver *d); + +/** + * ssam_device_driver_register() - Register a SSAM client device driver. + * @drv: The driver to register. + */ +#define ssam_device_driver_register(drv) \ + __ssam_device_driver_register(drv, THIS_MODULE) + +/** + * module_ssam_device_driver() - Helper macro for SSAM device driver + * registration. + * @drv: The driver managed by this module. + * + * Helper macro to register a SSAM device driver via module_init() and + * module_exit(). This macro may only be used once per module and replaces the + * aforementioned definitions. + */ +#define module_ssam_device_driver(drv) \ + module_driver(drv, ssam_device_driver_register, \ + ssam_device_driver_unregister) + + +/* -- Helpers for client-device requests. ----------------------------------- */ + +/** + * SSAM_DEFINE_SYNC_REQUEST_CL_N() - Define synchronous client-device SAM + * request function with neither argument nor return value. + * @name: Name of the generated function. + * @spec: Specification (&struct ssam_request_spec_md) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request having neither argument nor return value. Device + * specifying parameters are not hard-coded, but instead are provided via the + * client device, specifically its UID, supplied when calling this function. + * The generated function takes care of setting up the request struct, buffer + * allocation, as well as execution of the request itself, returning once the + * request has been fully completed. The required transport buffer will be + * allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_device *sdev)``, + * returning the status of the request, which is zero on success and negative + * on failure. The ``sdev`` parameter specifies both the target device of the + * request and by association the controller via which the request is sent. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_CL_N(name, spec...) \ + SSAM_DEFINE_SYNC_REQUEST_MD_N(__raw_##name, spec) \ + int name(struct ssam_device *sdev) \ + { \ + return __raw_##name(sdev->ctrl, sdev->uid.target, \ + sdev->uid.instance); \ + } + +/** + * SSAM_DEFINE_SYNC_REQUEST_CL_W() - Define synchronous client-device SAM + * request function with argument. + * @name: Name of the generated function. + * @atype: Type of the request's argument. + * @spec: Specification (&struct ssam_request_spec_md) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request taking an argument of type @atype and having no + * return value. Device specifying parameters are not hard-coded, but instead + * are provided via the client device, specifically its UID, supplied when + * calling this function. The generated function takes care of setting up the + * request struct, buffer allocation, as well as execution of the request + * itself, returning once the request has been fully completed. The required + * transport buffer will be allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_device *sdev, + * const atype *arg)``, returning the status of the request, which is zero on + * success and negative on failure. The ``sdev`` parameter specifies both the + * target device of the request and by association the controller via which + * the request is sent. The request's argument is specified via the ``arg`` + * pointer. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_CL_W(name, atype, spec...) \ + SSAM_DEFINE_SYNC_REQUEST_MD_W(__raw_##name, atype, spec) \ + int name(struct ssam_device *sdev, const atype *arg) \ + { \ + return __raw_##name(sdev->ctrl, sdev->uid.target, \ + sdev->uid.instance, arg); \ + } + +/** + * SSAM_DEFINE_SYNC_REQUEST_CL_R() - Define synchronous client-device SAM + * request function with return value. + * @name: Name of the generated function. + * @rtype: Type of the request's return value. + * @spec: Specification (&struct ssam_request_spec_md) defining the request. + * + * Defines a function executing the synchronous SAM request specified by + * @spec, with the request taking no argument but having a return value of + * type @rtype. Device specifying parameters are not hard-coded, but instead + * are provided via the client device, specifically its UID, supplied when + * calling this function. The generated function takes care of setting up the + * request struct, buffer allocation, as well as execution of the request + * itself, returning once the request has been fully completed. The required + * transport buffer will be allocated on the stack. + * + * The generated function is defined as ``int name(struct ssam_device *sdev, + * rtype *ret)``, returning the status of the request, which is zero on + * success and negative on failure. The ``sdev`` parameter specifies both the + * target device of the request and by association the controller via which + * the request is sent. The request's return value is written to the memory + * pointed to by the ``ret`` parameter. + * + * Refer to ssam_request_sync_onstack() for more details on the behavior of + * the generated function. + */ +#define SSAM_DEFINE_SYNC_REQUEST_CL_R(name, rtype, spec...) \ + SSAM_DEFINE_SYNC_REQUEST_MD_R(__raw_##name, rtype, spec) \ + int name(struct ssam_device *sdev, rtype *ret) \ + { \ + return __raw_##name(sdev->ctrl, sdev->uid.target, \ + sdev->uid.instance, ret); \ + } + +#endif /* _LINUX_SURFACE_AGGREGATOR_DEVICE_H */ diff --git a/scripts/mod/devicetable-offsets.c b/scripts/mod/devicetable-offsets.c index e377f52dbfa3..f078eeb0a961 100644 --- a/scripts/mod/devicetable-offsets.c +++ b/scripts/mod/devicetable-offsets.c @@ -246,5 +246,13 @@ int main(void) DEVID(auxiliary_device_id); DEVID_FIELD(auxiliary_device_id, name); + DEVID(ssam_device_id); + DEVID_FIELD(ssam_device_id, match_flags); + DEVID_FIELD(ssam_device_id, domain); + DEVID_FIELD(ssam_device_id, category); + DEVID_FIELD(ssam_device_id, target); + DEVID_FIELD(ssam_device_id, instance); + DEVID_FIELD(ssam_device_id, function); + return 0; } diff --git a/scripts/mod/file2alias.c b/scripts/mod/file2alias.c index fb4827027536..d21d2871387b 100644 --- a/scripts/mod/file2alias.c +++ b/scripts/mod/file2alias.c @@ -1375,6 +1375,28 @@ static int do_auxiliary_entry(const char *filename, void *symval, char *alias) return 1; } +/* + * Looks like: ssam:dNcNtNiNfN + * + * N is exactly 2 digits, where each is an upper-case hex digit. + */ +static int do_ssam_entry(const char *filename, void *symval, char *alias) +{ + DEF_FIELD(symval, ssam_device_id, match_flags); + DEF_FIELD(symval, ssam_device_id, domain); + DEF_FIELD(symval, ssam_device_id, category); + DEF_FIELD(symval, ssam_device_id, target); + DEF_FIELD(symval, ssam_device_id, instance); + DEF_FIELD(symval, ssam_device_id, function); + + sprintf(alias, "ssam:d%02Xc%02X", domain, category); + ADD(alias, "t", match_flags & SSAM_MATCH_TARGET, target); + ADD(alias, "i", match_flags & SSAM_MATCH_INSTANCE, instance); + ADD(alias, "f", match_flags & SSAM_MATCH_FUNCTION, function); + + return 1; +} + /* Does namelen bytes of name exactly match the symbol? */ static bool sym_is(const char *name, unsigned namelen, const char *symbol) { @@ -1450,6 +1472,7 @@ static const struct devtable devtable[] = { {"wmi", SIZE_wmi_device_id, do_wmi_entry}, {"mhi", SIZE_mhi_device_id, do_mhi_entry}, {"auxiliary", SIZE_auxiliary_device_id, do_auxiliary_entry}, + {"ssam", SIZE_ssam_device_id, do_ssam_entry}, }; /* Create MODULE_ALIAS() statements. -- cgit v1.2.3 From 178f6ab77e617c984d6520b92e747075a12676ff Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Mon, 21 Dec 2020 19:39:58 +0100 Subject: platform/surface: Add Surface Aggregator user-space interface Add a misc-device providing user-space access to the Surface Aggregator EC, mainly intended for debugging, testing, and reverse-engineering. This interface gives user-space applications the ability to send requests to the EC and receive the corresponding responses. The device-file is managed by a pseudo platform-device and corresponding driver to avoid dependence on the dedicated bus, allowing it to be loaded in a minimal configuration. A python library and scripts to access this device can be found at [1]. [1]: https://github.com/linux-surface/surface-aggregator-module/tree/master/scripts/ssam Signed-off-by: Maximilian Luz Link: https://lore.kernel.org/r/20201221183959.1186143-9-luzmaximilian@gmail.com Signed-off-by: Hans de Goede --- .../driver-api/surface_aggregator/clients/cdev.rst | 87 ++++++ .../surface_aggregator/clients/index.rst | 12 +- Documentation/userspace-api/ioctl/ioctl-number.rst | 2 + MAINTAINERS | 2 + drivers/platform/surface/Kconfig | 17 ++ drivers/platform/surface/Makefile | 1 + drivers/platform/surface/surface_aggregator_cdev.c | 303 +++++++++++++++++++++ include/uapi/linux/surface_aggregator/cdev.h | 78 ++++++ 8 files changed, 501 insertions(+), 1 deletion(-) create mode 100644 Documentation/driver-api/surface_aggregator/clients/cdev.rst create mode 100644 drivers/platform/surface/surface_aggregator_cdev.c create mode 100644 include/uapi/linux/surface_aggregator/cdev.h (limited to 'include') diff --git a/Documentation/driver-api/surface_aggregator/clients/cdev.rst b/Documentation/driver-api/surface_aggregator/clients/cdev.rst new file mode 100644 index 000000000000..248c1372d879 --- /dev/null +++ b/Documentation/driver-api/surface_aggregator/clients/cdev.rst @@ -0,0 +1,87 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +.. |u8| replace:: :c:type:`u8 ` +.. |u16| replace:: :c:type:`u16 ` +.. |ssam_cdev_request| replace:: :c:type:`struct ssam_cdev_request ` +.. |ssam_cdev_request_flags| replace:: :c:type:`enum ssam_cdev_request_flags ` + +============================== +User-Space EC Interface (cdev) +============================== + +The ``surface_aggregator_cdev`` module provides a misc-device for the SSAM +controller to allow for a (more or less) direct connection from user-space to +the SAM EC. It is intended to be used for development and debugging, and +therefore should not be used or relied upon in any other way. Note that this +module is not loaded automatically, but instead must be loaded manually. + +The provided interface is accessible through the ``/dev/surface/aggregator`` +device-file. All functionality of this interface is provided via IOCTLs. +These IOCTLs and their respective input/output parameter structs are defined in +``include/uapi/linux/surface_aggregator/cdev.h``. + +A small python library and scripts for accessing this interface can be found +at https://github.com/linux-surface/surface-aggregator-module/tree/master/scripts/ssam. + + +Controller IOCTLs +================= + +The following IOCTLs are provided: + +.. flat-table:: Controller IOCTLs + :widths: 1 1 1 1 4 + :header-rows: 1 + + * - Type + - Number + - Direction + - Name + - Description + + * - ``0xA5`` + - ``1`` + - ``WR`` + - ``REQUEST`` + - Perform synchronous SAM request. + + +``REQUEST`` +----------- + +Defined as ``_IOWR(0xA5, 1, struct ssam_cdev_request)``. + +Executes a synchronous SAM request. The request specification is passed in +as argument of type |ssam_cdev_request|, which is then written to/modified +by the IOCTL to return status and result of the request. + +Request payload data must be allocated separately and is passed in via the +``payload.data`` and ``payload.length`` members. If a response is required, +the response buffer must be allocated by the caller and passed in via the +``response.data`` member. The ``response.length`` member must be set to the +capacity of this buffer, or if no response is required, zero. Upon +completion of the request, the call will write the response to the response +buffer (if its capacity allows it) and overwrite the length field with the +actual size of the response, in bytes. + +Additionally, if the request has a response, this must be indicated via the +request flags, as is done with in-kernel requests. Request flags can be set +via the ``flags`` member and the values correspond to the values found in +|ssam_cdev_request_flags|. + +Finally, the status of the request itself is returned in the ``status`` +member (a negative errno value indicating failure). Note that failure +indication of the IOCTL is separated from failure indication of the request: +The IOCTL returns a negative status code if anything failed during setup of +the request (``-EFAULT``) or if the provided argument or any of its fields +are invalid (``-EINVAL``). In this case, the status value of the request +argument may be set, providing more detail on what went wrong (e.g. +``-ENOMEM`` for out-of-memory), but this value may also be zero. The IOCTL +will return with a zero status code in case the request has been set up, +submitted, and completed (i.e. handed back to user-space) successfully from +inside the IOCTL, but the request ``status`` member may still be negative in +case the actual execution of the request failed after it has been submitted. + +A full definition of the argument struct is provided below: + +.. kernel-doc:: include/uapi/linux/surface_aggregator/cdev.h diff --git a/Documentation/driver-api/surface_aggregator/clients/index.rst b/Documentation/driver-api/surface_aggregator/clients/index.rst index 31e026d96102..ab260ec82cfb 100644 --- a/Documentation/driver-api/surface_aggregator/clients/index.rst +++ b/Documentation/driver-api/surface_aggregator/clients/index.rst @@ -7,4 +7,14 @@ Client Driver Documentation This is the documentation for client drivers themselves. Refer to :doc:`../client` for documentation on how to write client drivers. -.. Place documentation for individual client drivers here. +.. toctree:: + :maxdepth: 1 + + cdev + +.. only:: subproject and html + + Indices + ======= + + * :ref:`genindex` diff --git a/Documentation/userspace-api/ioctl/ioctl-number.rst b/Documentation/userspace-api/ioctl/ioctl-number.rst index a4c75a28c839..b5231d7f9200 100644 --- a/Documentation/userspace-api/ioctl/ioctl-number.rst +++ b/Documentation/userspace-api/ioctl/ioctl-number.rst @@ -324,6 +324,8 @@ Code Seq# Include File Comments 0xA3 90-9F linux/dtlk.h 0xA4 00-1F uapi/linux/tee.h Generic TEE subsystem 0xA4 00-1F uapi/asm/sgx.h +0xA5 01 linux/surface_aggregator/cdev.h Microsoft Surface Platform System Aggregator + 0xAA 00-3F linux/uapi/linux/userfaultfd.h 0xAB 00-1F linux/nbd.h 0xAC 00-1F linux/raw.h diff --git a/MAINTAINERS b/MAINTAINERS index 41f082551942..9bd55c842898 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11820,7 +11820,9 @@ W: https://github.com/linux-surface/surface-aggregator-module C: irc://chat.freenode.net/##linux-surface F: Documentation/driver-api/surface_aggregator/ F: drivers/platform/surface/aggregator/ +F: drivers/platform/surface/surface_aggregator_cdev.c F: include/linux/surface_aggregator/ +F: include/uapi/linux/surface_aggregator/ MICROTEK X6 SCANNER M: Oliver Neukum diff --git a/drivers/platform/surface/Kconfig b/drivers/platform/surface/Kconfig index 2916a47b130e..988b2de6b500 100644 --- a/drivers/platform/surface/Kconfig +++ b/drivers/platform/surface/Kconfig @@ -41,6 +41,23 @@ config SURFACE_3_POWER_OPREGION This driver provides support for ACPI operation region of the Surface 3 battery platform driver. +config SURFACE_AGGREGATOR_CDEV + tristate "Surface System Aggregator Module User-Space Interface" + depends on SURFACE_AGGREGATOR + help + Provides a misc-device interface to the Surface System Aggregator + Module (SSAM) controller. + + This option provides a module (called surface_aggregator_cdev), that, + when loaded, will add a client device (and its respective driver) to + the SSAM controller. Said client device manages a misc-device + interface (/dev/surface/aggregator), which can be used by user-space + tools to directly communicate with the SSAM EC by sending requests and + receiving the corresponding responses. + + The provided interface is intended for debugging and development only, + and should not be used otherwise. + config SURFACE_GPE tristate "Surface GPE/Lid Support Driver" depends on DMI diff --git a/drivers/platform/surface/Makefile b/drivers/platform/surface/Makefile index 034134fe0264..161f0ad05795 100644 --- a/drivers/platform/surface/Makefile +++ b/drivers/platform/surface/Makefile @@ -8,5 +8,6 @@ obj-$(CONFIG_SURFACE3_WMI) += surface3-wmi.o obj-$(CONFIG_SURFACE_3_BUTTON) += surface3_button.o obj-$(CONFIG_SURFACE_3_POWER_OPREGION) += surface3_power.o obj-$(CONFIG_SURFACE_AGGREGATOR) += aggregator/ +obj-$(CONFIG_SURFACE_AGGREGATOR_CDEV) += surface_aggregator_cdev.o obj-$(CONFIG_SURFACE_GPE) += surface_gpe.o obj-$(CONFIG_SURFACE_PRO3_BUTTON) += surfacepro3_button.o diff --git a/drivers/platform/surface/surface_aggregator_cdev.c b/drivers/platform/surface/surface_aggregator_cdev.c new file mode 100644 index 000000000000..340d15b148b9 --- /dev/null +++ b/drivers/platform/surface/surface_aggregator_cdev.c @@ -0,0 +1,303 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Provides user-space access to the SSAM EC via the /dev/surface/aggregator + * misc device. Intended for debugging and development. + * + * Copyright (C) 2020 Maximilian Luz + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +#define SSAM_CDEV_DEVICE_NAME "surface_aggregator_cdev" + +struct ssam_cdev { + struct kref kref; + struct rw_semaphore lock; + struct ssam_controller *ctrl; + struct miscdevice mdev; +}; + +static void __ssam_cdev_release(struct kref *kref) +{ + kfree(container_of(kref, struct ssam_cdev, kref)); +} + +static struct ssam_cdev *ssam_cdev_get(struct ssam_cdev *cdev) +{ + if (cdev) + kref_get(&cdev->kref); + + return cdev; +} + +static void ssam_cdev_put(struct ssam_cdev *cdev) +{ + if (cdev) + kref_put(&cdev->kref, __ssam_cdev_release); +} + +static int ssam_cdev_device_open(struct inode *inode, struct file *filp) +{ + struct miscdevice *mdev = filp->private_data; + struct ssam_cdev *cdev = container_of(mdev, struct ssam_cdev, mdev); + + filp->private_data = ssam_cdev_get(cdev); + return stream_open(inode, filp); +} + +static int ssam_cdev_device_release(struct inode *inode, struct file *filp) +{ + ssam_cdev_put(filp->private_data); + return 0; +} + +static long ssam_cdev_request(struct ssam_cdev *cdev, unsigned long arg) +{ + struct ssam_cdev_request __user *r; + struct ssam_cdev_request rqst; + struct ssam_request spec; + struct ssam_response rsp; + const void __user *plddata; + void __user *rspdata; + int status = 0, ret = 0, tmp; + + r = (struct ssam_cdev_request __user *)arg; + ret = copy_struct_from_user(&rqst, sizeof(rqst), r, sizeof(*r)); + if (ret) + goto out; + + plddata = u64_to_user_ptr(rqst.payload.data); + rspdata = u64_to_user_ptr(rqst.response.data); + + /* Setup basic request fields. */ + spec.target_category = rqst.target_category; + spec.target_id = rqst.target_id; + spec.command_id = rqst.command_id; + spec.instance_id = rqst.instance_id; + spec.flags = 0; + spec.length = rqst.payload.length; + spec.payload = NULL; + + if (rqst.flags & SSAM_CDEV_REQUEST_HAS_RESPONSE) + spec.flags |= SSAM_REQUEST_HAS_RESPONSE; + + if (rqst.flags & SSAM_CDEV_REQUEST_UNSEQUENCED) + spec.flags |= SSAM_REQUEST_UNSEQUENCED; + + rsp.capacity = rqst.response.length; + rsp.length = 0; + rsp.pointer = NULL; + + /* Get request payload from user-space. */ + if (spec.length) { + if (!plddata) { + ret = -EINVAL; + goto out; + } + + spec.payload = kzalloc(spec.length, GFP_KERNEL); + if (!spec.payload) { + ret = -ENOMEM; + goto out; + } + + if (copy_from_user((void *)spec.payload, plddata, spec.length)) { + ret = -EFAULT; + goto out; + } + } + + /* Allocate response buffer. */ + if (rsp.capacity) { + if (!rspdata) { + ret = -EINVAL; + goto out; + } + + rsp.pointer = kzalloc(rsp.capacity, GFP_KERNEL); + if (!rsp.pointer) { + ret = -ENOMEM; + goto out; + } + } + + /* Perform request. */ + status = ssam_request_sync(cdev->ctrl, &spec, &rsp); + if (status) + goto out; + + /* Copy response to user-space. */ + if (rsp.length && copy_to_user(rspdata, rsp.pointer, rsp.length)) + ret = -EFAULT; + +out: + /* Always try to set response-length and status. */ + tmp = put_user(rsp.length, &r->response.length); + if (tmp) + ret = tmp; + + tmp = put_user(status, &r->status); + if (tmp) + ret = tmp; + + /* Cleanup. */ + kfree(spec.payload); + kfree(rsp.pointer); + + return ret; +} + +static long __ssam_cdev_device_ioctl(struct ssam_cdev *cdev, unsigned int cmd, + unsigned long arg) +{ + switch (cmd) { + case SSAM_CDEV_REQUEST: + return ssam_cdev_request(cdev, arg); + + default: + return -ENOTTY; + } +} + +static long ssam_cdev_device_ioctl(struct file *file, unsigned int cmd, + unsigned long arg) +{ + struct ssam_cdev *cdev = file->private_data; + long status; + + /* Ensure that controller is valid for as long as we need it. */ + if (down_read_killable(&cdev->lock)) + return -ERESTARTSYS; + + if (!cdev->ctrl) { + up_read(&cdev->lock); + return -ENODEV; + } + + status = __ssam_cdev_device_ioctl(cdev, cmd, arg); + + up_read(&cdev->lock); + return status; +} + +static const struct file_operations ssam_controller_fops = { + .owner = THIS_MODULE, + .open = ssam_cdev_device_open, + .release = ssam_cdev_device_release, + .unlocked_ioctl = ssam_cdev_device_ioctl, + .compat_ioctl = ssam_cdev_device_ioctl, + .llseek = noop_llseek, +}; + +static int ssam_dbg_device_probe(struct platform_device *pdev) +{ + struct ssam_controller *ctrl; + struct ssam_cdev *cdev; + int status; + + ctrl = ssam_client_bind(&pdev->dev); + if (IS_ERR(ctrl)) + return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl); + + cdev = kzalloc(sizeof(*cdev), GFP_KERNEL); + if (!cdev) + return -ENOMEM; + + kref_init(&cdev->kref); + init_rwsem(&cdev->lock); + cdev->ctrl = ctrl; + + cdev->mdev.parent = &pdev->dev; + cdev->mdev.minor = MISC_DYNAMIC_MINOR; + cdev->mdev.name = "surface_aggregator"; + cdev->mdev.nodename = "surface/aggregator"; + cdev->mdev.fops = &ssam_controller_fops; + + status = misc_register(&cdev->mdev); + if (status) { + kfree(cdev); + return status; + } + + platform_set_drvdata(pdev, cdev); + return 0; +} + +static int ssam_dbg_device_remove(struct platform_device *pdev) +{ + struct ssam_cdev *cdev = platform_get_drvdata(pdev); + + misc_deregister(&cdev->mdev); + + /* + * The controller is only guaranteed to be valid for as long as the + * driver is bound. Remove controller so that any lingering open files + * cannot access it any more after we're gone. + */ + down_write(&cdev->lock); + cdev->ctrl = NULL; + up_write(&cdev->lock); + + ssam_cdev_put(cdev); + return 0; +} + +static struct platform_device *ssam_cdev_device; + +static struct platform_driver ssam_cdev_driver = { + .probe = ssam_dbg_device_probe, + .remove = ssam_dbg_device_remove, + .driver = { + .name = SSAM_CDEV_DEVICE_NAME, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; + +static int __init ssam_debug_init(void) +{ + int status; + + ssam_cdev_device = platform_device_alloc(SSAM_CDEV_DEVICE_NAME, + PLATFORM_DEVID_NONE); + if (!ssam_cdev_device) + return -ENOMEM; + + status = platform_device_add(ssam_cdev_device); + if (status) + goto err_device; + + status = platform_driver_register(&ssam_cdev_driver); + if (status) + goto err_driver; + + return 0; + +err_driver: + platform_device_del(ssam_cdev_device); +err_device: + platform_device_put(ssam_cdev_device); + return status; +} +module_init(ssam_debug_init); + +static void __exit ssam_debug_exit(void) +{ + platform_driver_unregister(&ssam_cdev_driver); + platform_device_unregister(ssam_cdev_device); +} +module_exit(ssam_debug_exit); + +MODULE_AUTHOR("Maximilian Luz "); +MODULE_DESCRIPTION("User-space interface for Surface System Aggregator Module"); +MODULE_LICENSE("GPL"); diff --git a/include/uapi/linux/surface_aggregator/cdev.h b/include/uapi/linux/surface_aggregator/cdev.h new file mode 100644 index 000000000000..fbcce04abfe9 --- /dev/null +++ b/include/uapi/linux/surface_aggregator/cdev.h @@ -0,0 +1,78 @@ +/* SPDX-License-Identifier: GPL-2.0+ WITH Linux-syscall-note */ +/* + * Surface System Aggregator Module (SSAM) user-space EC interface. + * + * Definitions, structs, and IOCTLs for the /dev/surface/aggregator misc + * device. This device provides direct user-space access to the SSAM EC. + * Intended for debugging and development. + * + * Copyright (C) 2020 Maximilian Luz + */ + +#ifndef _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H +#define _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H + +#include +#include + +/** + * enum ssam_cdev_request_flags - Request flags for SSAM cdev request IOCTL. + * + * @SSAM_CDEV_REQUEST_HAS_RESPONSE: + * Specifies that the request expects a response. If not set, the request + * will be directly completed after its underlying packet has been + * transmitted. If set, the request transport system waits for a response + * of the request. + * + * @SSAM_CDEV_REQUEST_UNSEQUENCED: + * Specifies that the request should be transmitted via an unsequenced + * packet. If set, the request must not have a response, meaning that this + * flag and the %SSAM_CDEV_REQUEST_HAS_RESPONSE flag are mutually + * exclusive. + */ +enum ssam_cdev_request_flags { + SSAM_CDEV_REQUEST_HAS_RESPONSE = 0x01, + SSAM_CDEV_REQUEST_UNSEQUENCED = 0x02, +}; + +/** + * struct ssam_cdev_request - Controller request IOCTL argument. + * @target_category: Target category of the SAM request. + * @target_id: Target ID of the SAM request. + * @command_id: Command ID of the SAM request. + * @instance_id: Instance ID of the SAM request. + * @flags: Request flags (see &enum ssam_cdev_request_flags). + * @status: Request status (output). + * @payload: Request payload (input data). + * @payload.data: Pointer to request payload data. + * @payload.length: Length of request payload data (in bytes). + * @response: Request response (output data). + * @response.data: Pointer to response buffer. + * @response.length: On input: Capacity of response buffer (in bytes). + * On output: Length of request response (number of bytes + * in the buffer that are actually used). + */ +struct ssam_cdev_request { + __u8 target_category; + __u8 target_id; + __u8 command_id; + __u8 instance_id; + __u16 flags; + __s16 status; + + struct { + __u64 data; + __u16 length; + __u8 __pad[6]; + } payload; + + struct { + __u64 data; + __u16 length; + __u8 __pad[6]; + } response; +} __attribute__((__packed__)); + +#define SSAM_CDEV_REQUEST _IOWR(0xA5, 1, struct ssam_cdev_request) + +#endif /* _UAPI_LINUX_SURFACE_AGGREGATOR_CDEV_H */ -- cgit v1.2.3 From fc00bc8ac1dada4085f9308f85f2d6359da0faa8 Mon Sep 17 00:00:00 2001 From: Maximilian Luz Date: Mon, 21 Dec 2020 19:39:59 +0100 Subject: platform/surface: Add Surface ACPI Notify driver The Surface ACPI Notify (SAN) device provides an ACPI interface to the Surface Aggregator EC, specifically the Surface Serial Hub interface. This interface allows EC requests to be made from ACPI code and can convert a subset of EC events back to ACPI notifications. Specifically, this interface provides a GenericSerialBus operation region ACPI code can execute a request by writing the request command data and payload to this operation region and reading back the corresponding response via a write-then-read operation. Furthermore, this interface provides a _DSM method to be called when certain events from the EC have been received, essentially turning them into ACPI notifications. The driver provided in this commit essentially takes care of translating the request data written to the operation region, executing the request, waiting for it to finish, and finally writing and translating back the response (if the request has one). Furthermore, this driver takes care of enabling the events handled via ACPI _DSM calls. Lastly, this driver also exposes an interface providing discrete GPU (dGPU) power-on notifications on the Surface Book 2, which are also received via the operation region interface (but not handled by the SAN driver directly), making them accessible to other drivers (such as a dGPU hot-plug driver that may be added later on). On 5th and 6th generation Surface devices (Surface Pro 5/2017, Pro 6, Book 2, Laptop 1 and 2), the SAN interface provides full battery and thermal subsystem access, as well as other EC based functionality. On those models, battery and thermal sensor devices are implemented as standard ACPI devices of that type, however, forward ACPI calls to the corresponding Surface Aggregator EC request via the SAN interface and receive corresponding notifications (e.g. battery information change) from it. This interface is therefore required to provide said functionality on those devices. Signed-off-by: Maximilian Luz Reviewed-by: Hans de Goede Link: https://lore.kernel.org/r/20201221183959.1186143-10-luzmaximilian@gmail.com Signed-off-by: Hans de Goede --- .../surface_aggregator/clients/index.rst | 1 + .../driver-api/surface_aggregator/clients/san.rst | 44 + MAINTAINERS | 2 + drivers/platform/surface/Kconfig | 19 + drivers/platform/surface/Makefile | 1 + drivers/platform/surface/surface_acpi_notify.c | 886 +++++++++++++++++++++ include/linux/surface_acpi_notify.h | 39 + 7 files changed, 992 insertions(+) create mode 100644 Documentation/driver-api/surface_aggregator/clients/san.rst create mode 100644 drivers/platform/surface/surface_acpi_notify.c create mode 100644 include/linux/surface_acpi_notify.h (limited to 'include') diff --git a/Documentation/driver-api/surface_aggregator/clients/index.rst b/Documentation/driver-api/surface_aggregator/clients/index.rst index ab260ec82cfb..3ccabce23271 100644 --- a/Documentation/driver-api/surface_aggregator/clients/index.rst +++ b/Documentation/driver-api/surface_aggregator/clients/index.rst @@ -11,6 +11,7 @@ This is the documentation for client drivers themselves. Refer to :maxdepth: 1 cdev + san .. only:: subproject and html diff --git a/Documentation/driver-api/surface_aggregator/clients/san.rst b/Documentation/driver-api/surface_aggregator/clients/san.rst new file mode 100644 index 000000000000..38c2580e7758 --- /dev/null +++ b/Documentation/driver-api/surface_aggregator/clients/san.rst @@ -0,0 +1,44 @@ +.. SPDX-License-Identifier: GPL-2.0+ + +.. |san_client_link| replace:: :c:func:`san_client_link` +.. |san_dgpu_notifier_register| replace:: :c:func:`san_dgpu_notifier_register` +.. |san_dgpu_notifier_unregister| replace:: :c:func:`san_dgpu_notifier_unregister` + +=================== +Surface ACPI Notify +=================== + +The Surface ACPI Notify (SAN) device provides the bridge between ACPI and +SAM controller. Specifically, ACPI code can execute requests and handle +battery and thermal events via this interface. In addition to this, events +relating to the discrete GPU (dGPU) of the Surface Book 2 can be sent from +ACPI code (note: the Surface Book 3 uses a different method for this). The +only currently known event sent via this interface is a dGPU power-on +notification. While this driver handles the former part internally, it only +relays the dGPU events to any other driver interested via its public API and +does not handle them. + +The public interface of this driver is split into two parts: Client +registration and notifier-block registration. + +A client to the SAN interface can be linked as consumer to the SAN device +via |san_client_link|. This can be used to ensure that the a client +receiving dGPU events does not miss any events due to the SAN interface not +being set up as this forces the client driver to unbind once the SAN driver +is unbound. + +Notifier-blocks can be registered by any device for as long as the module is +loaded, regardless of being linked as client or not. Registration is done +with |san_dgpu_notifier_register|. If the notifier is not needed any more, it +should be unregistered via |san_dgpu_notifier_unregister|. + +Consult the API documentation below for more details. + + +API Documentation +================= + +.. kernel-doc:: include/linux/surface_acpi_notify.h + +.. kernel-doc:: drivers/platform/surface/surface_acpi_notify.c + :export: diff --git a/MAINTAINERS b/MAINTAINERS index 9bd55c842898..cf250c1365b0 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -11820,7 +11820,9 @@ W: https://github.com/linux-surface/surface-aggregator-module C: irc://chat.freenode.net/##linux-surface F: Documentation/driver-api/surface_aggregator/ F: drivers/platform/surface/aggregator/ +F: drivers/platform/surface/surface_acpi_notify.c F: drivers/platform/surface/surface_aggregator_cdev.c +F: include/linux/surface_acpi_notify.h F: include/linux/surface_aggregator/ F: include/uapi/linux/surface_aggregator/ diff --git a/drivers/platform/surface/Kconfig b/drivers/platform/surface/Kconfig index 988b2de6b500..83b0a4c7b352 100644 --- a/drivers/platform/surface/Kconfig +++ b/drivers/platform/surface/Kconfig @@ -41,6 +41,25 @@ config SURFACE_3_POWER_OPREGION This driver provides support for ACPI operation region of the Surface 3 battery platform driver. +config SURFACE_ACPI_NOTIFY + tristate "Surface ACPI Notify Driver" + depends on SURFACE_AGGREGATOR + help + Surface ACPI Notify (SAN) driver for Microsoft Surface devices. + + This driver provides support for the ACPI interface (called SAN) of + the Surface System Aggregator Module (SSAM) EC. This interface is used + on 5th- and 6th-generation Microsoft Surface devices (including + Surface Pro 5 and 6, Surface Book 2, Surface Laptops 1 and 2, and in + reduced functionality on the Surface Laptop 3) to execute SSAM + requests directly from ACPI code, as well as receive SSAM events and + turn them into ACPI notifications. It essentially acts as a + translation layer between the SSAM controller and ACPI. + + Specifically, this driver may be needed for battery status reporting, + thermal sensor access, and real-time clock information, depending on + the Surface device in question. + config SURFACE_AGGREGATOR_CDEV tristate "Surface System Aggregator Module User-Space Interface" depends on SURFACE_AGGREGATOR diff --git a/drivers/platform/surface/Makefile b/drivers/platform/surface/Makefile index 161f0ad05795..3eb971006877 100644 --- a/drivers/platform/surface/Makefile +++ b/drivers/platform/surface/Makefile @@ -7,6 +7,7 @@ obj-$(CONFIG_SURFACE3_WMI) += surface3-wmi.o obj-$(CONFIG_SURFACE_3_BUTTON) += surface3_button.o obj-$(CONFIG_SURFACE_3_POWER_OPREGION) += surface3_power.o +obj-$(CONFIG_SURFACE_ACPI_NOTIFY) += surface_acpi_notify.o obj-$(CONFIG_SURFACE_AGGREGATOR) += aggregator/ obj-$(CONFIG_SURFACE_AGGREGATOR_CDEV) += surface_aggregator_cdev.o obj-$(CONFIG_SURFACE_GPE) += surface_gpe.o diff --git a/drivers/platform/surface/surface_acpi_notify.c b/drivers/platform/surface/surface_acpi_notify.c new file mode 100644 index 000000000000..8cd67a669c86 --- /dev/null +++ b/drivers/platform/surface/surface_acpi_notify.c @@ -0,0 +1,886 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for the Surface ACPI Notify (SAN) interface/shim. + * + * Translates communication from ACPI to Surface System Aggregator Module + * (SSAM/SAM) requests and back, specifically SAM-over-SSH. Translates SSAM + * events back to ACPI notifications. Allows handling of discrete GPU + * notifications sent from ACPI via the SAN interface by providing them to any + * registered external driver. + * + * Copyright (C) 2019-2020 Maximilian Luz + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include +#include + +struct san_data { + struct device *dev; + struct ssam_controller *ctrl; + + struct acpi_connection_info info; + + struct ssam_event_notifier nf_bat; + struct ssam_event_notifier nf_tmp; +}; + +#define to_san_data(ptr, member) \ + container_of(ptr, struct san_data, member) + + +/* -- dGPU notifier interface. ---------------------------------------------- */ + +struct san_rqsg_if { + struct rw_semaphore lock; + struct device *dev; + struct blocking_notifier_head nh; +}; + +static struct san_rqsg_if san_rqsg_if = { + .lock = __RWSEM_INITIALIZER(san_rqsg_if.lock), + .dev = NULL, + .nh = BLOCKING_NOTIFIER_INIT(san_rqsg_if.nh), +}; + +static int san_set_rqsg_interface_device(struct device *dev) +{ + int status = 0; + + down_write(&san_rqsg_if.lock); + if (!san_rqsg_if.dev && dev) + san_rqsg_if.dev = dev; + else + status = -EBUSY; + up_write(&san_rqsg_if.lock); + + return status; +} + +/** + * san_client_link() - Link client as consumer to SAN device. + * @client: The client to link. + * + * Sets up a device link between the provided client device as consumer and + * the SAN device as provider. This function can be used to ensure that the + * SAN interface has been set up and will be set up for as long as the driver + * of the client device is bound. This guarantees that, during that time, all + * dGPU events will be received by any registered notifier. + * + * The link will be automatically removed once the client device's driver is + * unbound. + * + * Return: Returns zero on success, %-ENXIO if the SAN interface has not been + * set up yet, and %-ENOMEM if device link creation failed. + */ +int san_client_link(struct device *client) +{ + const u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_CONSUMER; + struct device_link *link; + + down_read(&san_rqsg_if.lock); + + if (!san_rqsg_if.dev) { + up_read(&san_rqsg_if.lock); + return -ENXIO; + } + + link = device_link_add(client, san_rqsg_if.dev, flags); + if (!link) { + up_read(&san_rqsg_if.lock); + return -ENOMEM; + } + + if (READ_ONCE(link->status) == DL_STATE_SUPPLIER_UNBIND) { + up_read(&san_rqsg_if.lock); + return -ENXIO; + } + + up_read(&san_rqsg_if.lock); + return 0; +} +EXPORT_SYMBOL_GPL(san_client_link); + +/** + * san_dgpu_notifier_register() - Register a SAN dGPU notifier. + * @nb: The notifier-block to register. + * + * Registers a SAN dGPU notifier, receiving any new SAN dGPU events sent from + * ACPI. The registered notifier will be called with &struct san_dgpu_event + * as notifier data and the command ID of that event as notifier action. + */ +int san_dgpu_notifier_register(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&san_rqsg_if.nh, nb); +} +EXPORT_SYMBOL_GPL(san_dgpu_notifier_register); + +/** + * san_dgpu_notifier_unregister() - Unregister a SAN dGPU notifier. + * @nb: The notifier-block to unregister. + */ +int san_dgpu_notifier_unregister(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&san_rqsg_if.nh, nb); +} +EXPORT_SYMBOL_GPL(san_dgpu_notifier_unregister); + +static int san_dgpu_notifier_call(struct san_dgpu_event *evt) +{ + int ret; + + ret = blocking_notifier_call_chain(&san_rqsg_if.nh, evt->command, evt); + return notifier_to_errno(ret); +} + + +/* -- ACPI _DSM event relay. ------------------------------------------------ */ + +#define SAN_DSM_REVISION 0 + +/* 93b666c5-70c6-469f-a215-3d487c91ab3c */ +static const guid_t SAN_DSM_UUID = + GUID_INIT(0x93b666c5, 0x70c6, 0x469f, 0xa2, 0x15, 0x3d, + 0x48, 0x7c, 0x91, 0xab, 0x3c); + +enum san_dsm_event_fn { + SAN_DSM_EVENT_FN_BAT1_STAT = 0x03, + SAN_DSM_EVENT_FN_BAT1_INFO = 0x04, + SAN_DSM_EVENT_FN_ADP1_STAT = 0x05, + SAN_DSM_EVENT_FN_ADP1_INFO = 0x06, + SAN_DSM_EVENT_FN_BAT2_STAT = 0x07, + SAN_DSM_EVENT_FN_BAT2_INFO = 0x08, + SAN_DSM_EVENT_FN_THERMAL = 0x09, + SAN_DSM_EVENT_FN_DPTF = 0x0a, +}; + +enum sam_event_cid_bat { + SAM_EVENT_CID_BAT_BIX = 0x15, + SAM_EVENT_CID_BAT_BST = 0x16, + SAM_EVENT_CID_BAT_ADP = 0x17, + SAM_EVENT_CID_BAT_PROT = 0x18, + SAM_EVENT_CID_BAT_DPTF = 0x4f, +}; + +enum sam_event_cid_tmp { + SAM_EVENT_CID_TMP_TRIP = 0x0b, +}; + +struct san_event_work { + struct delayed_work work; + struct device *dev; + struct ssam_event event; /* must be last */ +}; + +static int san_acpi_notify_event(struct device *dev, u64 func, + union acpi_object *param) +{ + acpi_handle san = ACPI_HANDLE(dev); + union acpi_object *obj; + int status = 0; + + if (!acpi_check_dsm(san, &SAN_DSM_UUID, SAN_DSM_REVISION, 1 << func)) + return 0; + + dev_dbg(dev, "notify event %#04llx\n", func); + + obj = acpi_evaluate_dsm_typed(san, &SAN_DSM_UUID, SAN_DSM_REVISION, + func, param, ACPI_TYPE_BUFFER); + if (!obj) + return -EFAULT; + + if (obj->buffer.length != 1 || obj->buffer.pointer[0] != 0) { + dev_err(dev, "got unexpected result from _DSM\n"); + status = -EPROTO; + } + + ACPI_FREE(obj); + return status; +} + +static int san_evt_bat_adp(struct device *dev, const struct ssam_event *event) +{ + int status; + + status = san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_ADP1_STAT, NULL); + if (status) + return status; + + /* + * Ensure that the battery states get updated correctly. When the + * battery is fully charged and an adapter is plugged in, it sometimes + * is not updated correctly, instead showing it as charging. + * Explicitly trigger battery updates to fix this. + */ + + status = san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_BAT1_STAT, NULL); + if (status) + return status; + + return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_BAT2_STAT, NULL); +} + +static int san_evt_bat_bix(struct device *dev, const struct ssam_event *event) +{ + enum san_dsm_event_fn fn; + + if (event->instance_id == 0x02) + fn = SAN_DSM_EVENT_FN_BAT2_INFO; + else + fn = SAN_DSM_EVENT_FN_BAT1_INFO; + + return san_acpi_notify_event(dev, fn, NULL); +} + +static int san_evt_bat_bst(struct device *dev, const struct ssam_event *event) +{ + enum san_dsm_event_fn fn; + + if (event->instance_id == 0x02) + fn = SAN_DSM_EVENT_FN_BAT2_STAT; + else + fn = SAN_DSM_EVENT_FN_BAT1_STAT; + + return san_acpi_notify_event(dev, fn, NULL); +} + +static int san_evt_bat_dptf(struct device *dev, const struct ssam_event *event) +{ + union acpi_object payload; + + /* + * The Surface ACPI expects a buffer and not a package. It specifically + * checks for ObjectType (Arg3) == 0x03. This will cause a warning in + * acpica/nsarguments.c, but that warning can be safely ignored. + */ + payload.type = ACPI_TYPE_BUFFER; + payload.buffer.length = event->length; + payload.buffer.pointer = (u8 *)&event->data[0]; + + return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_DPTF, &payload); +} + +static unsigned long san_evt_bat_delay(u8 cid) +{ + switch (cid) { + case SAM_EVENT_CID_BAT_ADP: + /* + * Wait for battery state to update before signaling adapter + * change. + */ + return msecs_to_jiffies(5000); + + case SAM_EVENT_CID_BAT_BST: + /* Ensure we do not miss anything important due to caching. */ + return msecs_to_jiffies(2000); + + default: + return 0; + } +} + +static bool san_evt_bat(const struct ssam_event *event, struct device *dev) +{ + int status; + + switch (event->command_id) { + case SAM_EVENT_CID_BAT_BIX: + status = san_evt_bat_bix(dev, event); + break; + + case SAM_EVENT_CID_BAT_BST: + status = san_evt_bat_bst(dev, event); + break; + + case SAM_EVENT_CID_BAT_ADP: + status = san_evt_bat_adp(dev, event); + break; + + case SAM_EVENT_CID_BAT_PROT: + /* + * TODO: Implement support for battery protection status change + * event. + */ + return true; + + case SAM_EVENT_CID_BAT_DPTF: + status = san_evt_bat_dptf(dev, event); + break; + + default: + return false; + } + + if (status) { + dev_err(dev, "error handling power event (cid = %#04x)\n", + event->command_id); + } + + return true; +} + +static void san_evt_bat_workfn(struct work_struct *work) +{ + struct san_event_work *ev; + + ev = container_of(work, struct san_event_work, work.work); + san_evt_bat(&ev->event, ev->dev); + kfree(ev); +} + +static u32 san_evt_bat_nf(struct ssam_event_notifier *nf, + const struct ssam_event *event) +{ + struct san_data *d = to_san_data(nf, nf_bat); + struct san_event_work *work; + unsigned long delay = san_evt_bat_delay(event->command_id); + + if (delay == 0) + return san_evt_bat(event, d->dev) ? SSAM_NOTIF_HANDLED : 0; + + work = kzalloc(sizeof(*work) + event->length, GFP_KERNEL); + if (!work) + return ssam_notifier_from_errno(-ENOMEM); + + INIT_DELAYED_WORK(&work->work, san_evt_bat_workfn); + work->dev = d->dev; + + memcpy(&work->event, event, sizeof(struct ssam_event) + event->length); + + schedule_delayed_work(&work->work, delay); + return SSAM_NOTIF_HANDLED; +} + +static int san_evt_tmp_trip(struct device *dev, const struct ssam_event *event) +{ + union acpi_object param; + + /* + * The Surface ACPI expects an integer and not a package. This will + * cause a warning in acpica/nsarguments.c, but that warning can be + * safely ignored. + */ + param.type = ACPI_TYPE_INTEGER; + param.integer.value = event->instance_id; + + return san_acpi_notify_event(dev, SAN_DSM_EVENT_FN_THERMAL, ¶m); +} + +static bool san_evt_tmp(const struct ssam_event *event, struct device *dev) +{ + int status; + + switch (event->command_id) { + case SAM_EVENT_CID_TMP_TRIP: + status = san_evt_tmp_trip(dev, event); + break; + + default: + return false; + } + + if (status) { + dev_err(dev, "error handling thermal event (cid = %#04x)\n", + event->command_id); + } + + return true; +} + +static u32 san_evt_tmp_nf(struct ssam_event_notifier *nf, + const struct ssam_event *event) +{ + struct san_data *d = to_san_data(nf, nf_tmp); + + return san_evt_tmp(event, d->dev) ? SSAM_NOTIF_HANDLED : 0; +} + + +/* -- ACPI GSB OperationRegion handler -------------------------------------- */ + +struct gsb_data_in { + u8 cv; +} __packed; + +struct gsb_data_rqsx { + u8 cv; /* Command value (san_gsb_request_cv). */ + u8 tc; /* Target category. */ + u8 tid; /* Target ID. */ + u8 iid; /* Instance ID. */ + u8 snc; /* Expect-response-flag. */ + u8 cid; /* Command ID. */ + u16 cdl; /* Payload length. */ + u8 pld[]; /* Payload. */ +} __packed; + +struct gsb_data_etwl { + u8 cv; /* Command value (should be 0x02). */ + u8 etw3; /* Unknown. */ + u8 etw4; /* Unknown. */ + u8 msg[]; /* Error message (ASCIIZ). */ +} __packed; + +struct gsb_data_out { + u8 status; /* _SSH communication status. */ + u8 len; /* _SSH payload length. */ + u8 pld[]; /* _SSH payload. */ +} __packed; + +union gsb_buffer_data { + struct gsb_data_in in; /* Common input. */ + struct gsb_data_rqsx rqsx; /* RQSX input. */ + struct gsb_data_etwl etwl; /* ETWL input. */ + struct gsb_data_out out; /* Output. */ +}; + +struct gsb_buffer { + u8 status; /* GSB AttribRawProcess status. */ + u8 len; /* GSB AttribRawProcess length. */ + union gsb_buffer_data data; +} __packed; + +#define SAN_GSB_MAX_RQSX_PAYLOAD (U8_MAX - 2 - sizeof(struct gsb_data_rqsx)) +#define SAN_GSB_MAX_RESPONSE (U8_MAX - 2 - sizeof(struct gsb_data_out)) + +#define SAN_GSB_COMMAND 0 + +enum san_gsb_request_cv { + SAN_GSB_REQUEST_CV_RQST = 0x01, + SAN_GSB_REQUEST_CV_ETWL = 0x02, + SAN_GSB_REQUEST_CV_RQSG = 0x03, +}; + +#define SAN_REQUEST_NUM_TRIES 5 + +static acpi_status san_etwl(struct san_data *d, struct gsb_buffer *b) +{ + struct gsb_data_etwl *etwl = &b->data.etwl; + + if (b->len < sizeof(struct gsb_data_etwl)) { + dev_err(d->dev, "invalid ETWL package (len = %d)\n", b->len); + return AE_OK; + } + + dev_err(d->dev, "ETWL(%#04x, %#04x): %.*s\n", etwl->etw3, etwl->etw4, + (unsigned int)(b->len - sizeof(struct gsb_data_etwl)), + (char *)etwl->msg); + + /* Indicate success. */ + b->status = 0x00; + b->len = 0x00; + + return AE_OK; +} + +static +struct gsb_data_rqsx *san_validate_rqsx(struct device *dev, const char *type, + struct gsb_buffer *b) +{ + struct gsb_data_rqsx *rqsx = &b->data.rqsx; + + if (b->len < sizeof(struct gsb_data_rqsx)) { + dev_err(dev, "invalid %s package (len = %d)\n", type, b->len); + return NULL; + } + + if (get_unaligned(&rqsx->cdl) != b->len - sizeof(struct gsb_data_rqsx)) { + dev_err(dev, "bogus %s package (len = %d, cdl = %d)\n", + type, b->len, get_unaligned(&rqsx->cdl)); + return NULL; + } + + if (get_unaligned(&rqsx->cdl) > SAN_GSB_MAX_RQSX_PAYLOAD) { + dev_err(dev, "payload for %s package too large (cdl = %d)\n", + type, get_unaligned(&rqsx->cdl)); + return NULL; + } + + return rqsx; +} + +static void gsb_rqsx_response_error(struct gsb_buffer *gsb, int status) +{ + gsb->status = 0x00; + gsb->len = 0x02; + gsb->data.out.status = (u8)(-status); + gsb->data.out.len = 0x00; +} + +static void gsb_rqsx_response_success(struct gsb_buffer *gsb, u8 *ptr, size_t len) +{ + gsb->status = 0x00; + gsb->len = len + 2; + gsb->data.out.status = 0x00; + gsb->data.out.len = len; + + if (len) + memcpy(&gsb->data.out.pld[0], ptr, len); +} + +static acpi_status san_rqst_fixup_suspended(struct san_data *d, + struct ssam_request *rqst, + struct gsb_buffer *gsb) +{ + if (rqst->target_category == SSAM_SSH_TC_BAS && rqst->command_id == 0x0D) { + u8 base_state = 1; + + /* Base state quirk: + * The base state may be queried from ACPI when the EC is still + * suspended. In this case it will return '-EPERM'. This query + * will only be triggered from the ACPI lid GPE interrupt, thus + * we are either in laptop or studio mode (base status 0x01 or + * 0x02). Furthermore, we will only get here if the device (and + * EC) have been suspended. + * + * We now assume that the device is in laptop mode (0x01). This + * has the drawback that it will wake the device when unfolding + * it in studio mode, but it also allows us to avoid actively + * waiting for the EC to wake up, which may incur a notable + * delay. + */ + + dev_dbg(d->dev, "rqst: fixup: base-state quirk\n"); + + gsb_rqsx_response_success(gsb, &base_state, sizeof(base_state)); + return AE_OK; + } + + gsb_rqsx_response_error(gsb, -ENXIO); + return AE_OK; +} + +static acpi_status san_rqst(struct san_data *d, struct gsb_buffer *buffer) +{ + u8 rspbuf[SAN_GSB_MAX_RESPONSE]; + struct gsb_data_rqsx *gsb_rqst; + struct ssam_request rqst; + struct ssam_response rsp; + int status = 0; + + gsb_rqst = san_validate_rqsx(d->dev, "RQST", buffer); + if (!gsb_rqst) + return AE_OK; + + rqst.target_category = gsb_rqst->tc; + rqst.target_id = gsb_rqst->tid; + rqst.command_id = gsb_rqst->cid; + rqst.instance_id = gsb_rqst->iid; + rqst.flags = gsb_rqst->snc ? SSAM_REQUEST_HAS_RESPONSE : 0; + rqst.length = get_unaligned(&gsb_rqst->cdl); + rqst.payload = &gsb_rqst->pld[0]; + + rsp.capacity = ARRAY_SIZE(rspbuf); + rsp.length = 0; + rsp.pointer = &rspbuf[0]; + + /* Handle suspended device. */ + if (d->dev->power.is_suspended) { + dev_warn(d->dev, "rqst: device is suspended, not executing\n"); + return san_rqst_fixup_suspended(d, &rqst, buffer); + } + + status = __ssam_retry(ssam_request_sync_onstack, SAN_REQUEST_NUM_TRIES, + d->ctrl, &rqst, &rsp, SAN_GSB_MAX_RQSX_PAYLOAD); + + if (!status) { + gsb_rqsx_response_success(buffer, rsp.pointer, rsp.length); + } else { + dev_err(d->dev, "rqst: failed with error %d\n", status); + gsb_rqsx_response_error(buffer, status); + } + + return AE_OK; +} + +static acpi_status san_rqsg(struct san_data *d, struct gsb_buffer *buffer) +{ + struct gsb_data_rqsx *gsb_rqsg; + struct san_dgpu_event evt; + int status; + + gsb_rqsg = san_validate_rqsx(d->dev, "RQSG", buffer); + if (!gsb_rqsg) + return AE_OK; + + evt.category = gsb_rqsg->tc; + evt.target = gsb_rqsg->tid; + evt.command = gsb_rqsg->cid; + evt.instance = gsb_rqsg->iid; + evt.length = get_unaligned(&gsb_rqsg->cdl); + evt.payload = &gsb_rqsg->pld[0]; + + status = san_dgpu_notifier_call(&evt); + if (!status) { + gsb_rqsx_response_success(buffer, NULL, 0); + } else { + dev_err(d->dev, "rqsg: failed with error %d\n", status); + gsb_rqsx_response_error(buffer, status); + } + + return AE_OK; +} + +static acpi_status san_opreg_handler(u32 function, acpi_physical_address command, + u32 bits, u64 *value64, void *opreg_context, + void *region_context) +{ + struct san_data *d = to_san_data(opreg_context, info); + struct gsb_buffer *buffer = (struct gsb_buffer *)value64; + int accessor_type = (function & 0xFFFF0000) >> 16; + + if (command != SAN_GSB_COMMAND) { + dev_warn(d->dev, "unsupported command: %#04llx\n", command); + return AE_OK; + } + + if (accessor_type != ACPI_GSB_ACCESS_ATTRIB_RAW_PROCESS) { + dev_err(d->dev, "invalid access type: %#04x\n", accessor_type); + return AE_OK; + } + + /* Buffer must have at least contain the command-value. */ + if (buffer->len == 0) { + dev_err(d->dev, "request-package too small\n"); + return AE_OK; + } + + switch (buffer->data.in.cv) { + case SAN_GSB_REQUEST_CV_RQST: + return san_rqst(d, buffer); + + case SAN_GSB_REQUEST_CV_ETWL: + return san_etwl(d, buffer); + + case SAN_GSB_REQUEST_CV_RQSG: + return san_rqsg(d, buffer); + + default: + dev_warn(d->dev, "unsupported SAN0 request (cv: %#04x)\n", + buffer->data.in.cv); + return AE_OK; + } +} + + +/* -- Driver setup. --------------------------------------------------------- */ + +static int san_events_register(struct platform_device *pdev) +{ + struct san_data *d = platform_get_drvdata(pdev); + int status; + + d->nf_bat.base.priority = 1; + d->nf_bat.base.fn = san_evt_bat_nf; + d->nf_bat.event.reg = SSAM_EVENT_REGISTRY_SAM; + d->nf_bat.event.id.target_category = SSAM_SSH_TC_BAT; + d->nf_bat.event.id.instance = 0; + d->nf_bat.event.mask = SSAM_EVENT_MASK_TARGET; + d->nf_bat.event.flags = SSAM_EVENT_SEQUENCED; + + d->nf_tmp.base.priority = 1; + d->nf_tmp.base.fn = san_evt_tmp_nf; + d->nf_tmp.event.reg = SSAM_EVENT_REGISTRY_SAM; + d->nf_tmp.event.id.target_category = SSAM_SSH_TC_TMP; + d->nf_tmp.event.id.instance = 0; + d->nf_tmp.event.mask = SSAM_EVENT_MASK_TARGET; + d->nf_tmp.event.flags = SSAM_EVENT_SEQUENCED; + + status = ssam_notifier_register(d->ctrl, &d->nf_bat); + if (status) + return status; + + status = ssam_notifier_register(d->ctrl, &d->nf_tmp); + if (status) + ssam_notifier_unregister(d->ctrl, &d->nf_bat); + + return status; +} + +static void san_events_unregister(struct platform_device *pdev) +{ + struct san_data *d = platform_get_drvdata(pdev); + + ssam_notifier_unregister(d->ctrl, &d->nf_bat); + ssam_notifier_unregister(d->ctrl, &d->nf_tmp); +} + +#define san_consumer_printk(level, dev, handle, fmt, ...) \ +do { \ + char *path = ""; \ + struct acpi_buffer buffer = { \ + .length = ACPI_ALLOCATE_BUFFER, \ + .pointer = NULL, \ + }; \ + \ + if (ACPI_SUCCESS(acpi_get_name(handle, ACPI_FULL_PATHNAME, &buffer))) \ + path = buffer.pointer; \ + \ + dev_##level(dev, "[%s]: " fmt, path, ##__VA_ARGS__); \ + kfree(buffer.pointer); \ +} while (0) + +#define san_consumer_dbg(dev, handle, fmt, ...) \ + san_consumer_printk(dbg, dev, handle, fmt, ##__VA_ARGS__) + +#define san_consumer_warn(dev, handle, fmt, ...) \ + san_consumer_printk(warn, dev, handle, fmt, ##__VA_ARGS__) + +static bool is_san_consumer(struct platform_device *pdev, acpi_handle handle) +{ + struct acpi_handle_list dep_devices; + acpi_handle supplier = ACPI_HANDLE(&pdev->dev); + acpi_status status; + int i; + + if (!acpi_has_method(handle, "_DEP")) + return false; + + status = acpi_evaluate_reference(handle, "_DEP", NULL, &dep_devices); + if (ACPI_FAILURE(status)) { + san_consumer_dbg(&pdev->dev, handle, "failed to evaluate _DEP\n"); + return false; + } + + for (i = 0; i < dep_devices.count; i++) { + if (dep_devices.handles[i] == supplier) + return true; + } + + return false; +} + +static acpi_status san_consumer_setup(acpi_handle handle, u32 lvl, + void *context, void **rv) +{ + const u32 flags = DL_FLAG_PM_RUNTIME | DL_FLAG_AUTOREMOVE_SUPPLIER; + struct platform_device *pdev = context; + struct acpi_device *adev; + struct device_link *link; + + if (!is_san_consumer(pdev, handle)) + return AE_OK; + + /* Ignore ACPI devices that are not present. */ + if (acpi_bus_get_device(handle, &adev) != 0) + return AE_OK; + + san_consumer_dbg(&pdev->dev, handle, "creating device link\n"); + + /* Try to set up device links, ignore but log errors. */ + link = device_link_add(&adev->dev, &pdev->dev, flags); + if (!link) { + san_consumer_warn(&pdev->dev, handle, "failed to create device link\n"); + return AE_OK; + } + + return AE_OK; +} + +static int san_consumer_links_setup(struct platform_device *pdev) +{ + acpi_status status; + + status = acpi_walk_namespace(ACPI_TYPE_DEVICE, ACPI_ROOT_OBJECT, + ACPI_UINT32_MAX, san_consumer_setup, NULL, + pdev, NULL); + + return status ? -EFAULT : 0; +} + +static int san_probe(struct platform_device *pdev) +{ + acpi_handle san = ACPI_HANDLE(&pdev->dev); + struct ssam_controller *ctrl; + struct san_data *data; + acpi_status astatus; + int status; + + ctrl = ssam_client_bind(&pdev->dev); + if (IS_ERR(ctrl)) + return PTR_ERR(ctrl) == -ENODEV ? -EPROBE_DEFER : PTR_ERR(ctrl); + + status = san_consumer_links_setup(pdev); + if (status) + return status; + + data = devm_kzalloc(&pdev->dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + data->dev = &pdev->dev; + data->ctrl = ctrl; + + platform_set_drvdata(pdev, data); + + astatus = acpi_install_address_space_handler(san, ACPI_ADR_SPACE_GSBUS, + &san_opreg_handler, NULL, + &data->info); + if (ACPI_FAILURE(astatus)) + return -ENXIO; + + status = san_events_register(pdev); + if (status) + goto err_enable_events; + + status = san_set_rqsg_interface_device(&pdev->dev); + if (status) + goto err_install_dev; + + acpi_walk_dep_device_list(san); + return 0; + +err_install_dev: + san_events_unregister(pdev); +err_enable_events: + acpi_remove_address_space_handler(san, ACPI_ADR_SPACE_GSBUS, + &san_opreg_handler); + return status; +} + +static int san_remove(struct platform_device *pdev) +{ + acpi_handle san = ACPI_HANDLE(&pdev->dev); + + san_set_rqsg_interface_device(NULL); + acpi_remove_address_space_handler(san, ACPI_ADR_SPACE_GSBUS, + &san_opreg_handler); + san_events_unregister(pdev); + + /* + * We have unregistered our event sources. Now we need to ensure that + * all delayed works they may have spawned are run to completion. + */ + flush_scheduled_work(); + + return 0; +} + +static const struct acpi_device_id san_match[] = { + { "MSHW0091" }, + { }, +}; +MODULE_DEVICE_TABLE(acpi, san_match); + +static struct platform_driver surface_acpi_notify = { + .probe = san_probe, + .remove = san_remove, + .driver = { + .name = "surface_acpi_notify", + .acpi_match_table = san_match, + .probe_type = PROBE_PREFER_ASYNCHRONOUS, + }, +}; +module_platform_driver(surface_acpi_notify); + +MODULE_AUTHOR("Maximilian Luz "); +MODULE_DESCRIPTION("Surface ACPI Notify driver for Surface System Aggregator Module"); +MODULE_LICENSE("GPL"); diff --git a/include/linux/surface_acpi_notify.h b/include/linux/surface_acpi_notify.h new file mode 100644 index 000000000000..8e3e86c7d78c --- /dev/null +++ b/include/linux/surface_acpi_notify.h @@ -0,0 +1,39 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * Interface for Surface ACPI Notify (SAN) driver. + * + * Provides access to discrete GPU notifications sent from ACPI via the SAN + * driver, which are not handled by this driver directly. + * + * Copyright (C) 2019-2020 Maximilian Luz + */ + +#ifndef _LINUX_SURFACE_ACPI_NOTIFY_H +#define _LINUX_SURFACE_ACPI_NOTIFY_H + +#include +#include + +/** + * struct san_dgpu_event - Discrete GPU ACPI event. + * @category: Category of the event. + * @target: Target ID of the event source. + * @command: Command ID of the event. + * @instance: Instance ID of the event source. + * @length: Length of the event's payload data (in bytes). + * @payload: Pointer to the event's payload data. + */ +struct san_dgpu_event { + u8 category; + u8 target; + u8 command; + u8 instance; + u16 length; + u8 *payload; +}; + +int san_client_link(struct device *client); +int san_dgpu_notifier_register(struct notifier_block *nb); +int san_dgpu_notifier_unregister(struct notifier_block *nb); + +#endif /* _LINUX_SURFACE_ACPI_NOTIFY_H */ -- cgit v1.2.3 From 0627cc334d408953c0ff9ef8731325c2d02572ed Mon Sep 17 00:00:00 2001 From: Yue Zou Date: Mon, 18 Jan 2021 01:01:37 +0000 Subject: sony-laptop: Remove unneeded semicolon Remove a superfluous semicolon after function definition. Signed-off-by: Yue Zou Link: https://lore.kernel.org/r/20210118010137.214378-1-zouyue3@huawei.com Signed-off-by: Hans de Goede --- include/linux/sony-laptop.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'include') diff --git a/include/linux/sony-laptop.h b/include/linux/sony-laptop.h index 374d0fdb0743..1e3c92feea6e 100644 --- a/include/linux/sony-laptop.h +++ b/include/linux/sony-laptop.h @@ -31,7 +31,7 @@ #if IS_ENABLED(CONFIG_SONY_LAPTOP) int sony_pic_camera_command(int command, u8 value); #else -static inline int sony_pic_camera_command(int command, u8 value) { return 0; }; +static inline int sony_pic_camera_command(int command, u8 value) { return 0; } #endif #endif /* __KERNEL__ */ -- cgit v1.2.3