diff options
Diffstat (limited to 'drivers/platform/surface/aggregator/ssh_request_layer.h')
-rw-r--r-- | drivers/platform/surface/aggregator/ssh_request_layer.h | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/platform/surface/aggregator/ssh_request_layer.h b/drivers/platform/surface/aggregator/ssh_request_layer.h new file mode 100644 index 000000000000..cb35815858d1 --- /dev/null +++ b/drivers/platform/surface/aggregator/ssh_request_layer.h @@ -0,0 +1,143 @@ +/* SPDX-License-Identifier: GPL-2.0+ */ +/* + * SSH request transport layer. + * + * Copyright (C) 2019-2020 Maximilian Luz <luzmaximilian@gmail.com> + */ + +#ifndef _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H +#define _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H + +#include <linux/atomic.h> +#include <linux/ktime.h> +#include <linux/list.h> +#include <linux/spinlock.h> +#include <linux/workqueue.h> + +#include <linux/surface_aggregator/serial_hub.h> +#include <linux/surface_aggregator/controller.h> + +#include "ssh_packet_layer.h" + +/** + * enum ssh_rtl_state_flags - State-flags for &struct ssh_rtl. + * + * @SSH_RTL_SF_SHUTDOWN_BIT: + * Indicates that the request transport layer has been shut down or is + * being shut down and should not accept any new requests. + */ +enum ssh_rtl_state_flags { + SSH_RTL_SF_SHUTDOWN_BIT, +}; + +/** + * struct ssh_rtl_ops - Callback operations for request transport layer. + * @handle_event: Function called when a SSH event has been received. The + * specified function takes the request layer, received command + * struct, and corresponding payload as arguments. If the event + * has no payload, the payload span is empty (not %NULL). + */ +struct ssh_rtl_ops { + void (*handle_event)(struct ssh_rtl *rtl, const struct ssh_command *cmd, + const struct ssam_span *data); +}; + +/** + * struct ssh_rtl - SSH request transport layer. + * @ptl: Underlying packet transport layer. + * @state: State(-flags) of the transport layer. + * @queue: Request submission queue. + * @queue.lock: Lock for modifying the request submission queue. + * @queue.head: List-head of the request submission queue. + * @pending: Set/list of pending requests. + * @pending.lock: Lock for modifying the request set. + * @pending.head: List-head of the pending set/list. + * @pending.count: Number of currently pending requests. + * @tx: Transmitter subsystem. + * @tx.work: Transmitter work item. + * @rtx_timeout: Retransmission timeout subsystem. + * @rtx_timeout.lock: Lock for modifying the retransmission timeout reaper. + * @rtx_timeout.timeout: Timeout interval for retransmission. + * @rtx_timeout.expires: Time specifying when the reaper work is next scheduled. + * @rtx_timeout.reaper: Work performing timeout checks and subsequent actions. + * @ops: Request layer operations. + */ +struct ssh_rtl { + struct ssh_ptl ptl; + unsigned long state; + + struct { + spinlock_t lock; + struct list_head head; + } queue; + + struct { + spinlock_t lock; + struct list_head head; + atomic_t count; + } pending; + + struct { + struct work_struct work; + } tx; + + struct { + spinlock_t lock; + ktime_t timeout; + ktime_t expires; + struct delayed_work reaper; + } rtx_timeout; + + struct ssh_rtl_ops ops; +}; + +#define rtl_dbg(r, fmt, ...) ptl_dbg(&(r)->ptl, fmt, ##__VA_ARGS__) +#define rtl_info(p, fmt, ...) ptl_info(&(p)->ptl, fmt, ##__VA_ARGS__) +#define rtl_warn(r, fmt, ...) ptl_warn(&(r)->ptl, fmt, ##__VA_ARGS__) +#define rtl_err(r, fmt, ...) ptl_err(&(r)->ptl, fmt, ##__VA_ARGS__) +#define rtl_dbg_cond(r, fmt, ...) __ssam_prcond(rtl_dbg, r, fmt, ##__VA_ARGS__) + +#define to_ssh_rtl(ptr, member) \ + container_of(ptr, struct ssh_rtl, member) + +/** + * ssh_rtl_get_device() - Get device associated with request transport layer. + * @rtl: The request transport layer. + * + * Return: Returns the device on which the given request transport layer + * builds upon. + */ +static inline struct device *ssh_rtl_get_device(struct ssh_rtl *rtl) +{ + return ssh_ptl_get_device(&rtl->ptl); +} + +/** + * ssh_request_rtl() - Get request transport layer associated with request. + * @rqst: The request to get the request transport layer reference for. + * + * Return: Returns the &struct ssh_rtl associated with the given SSH request. + */ +static inline struct ssh_rtl *ssh_request_rtl(struct ssh_request *rqst) +{ + struct ssh_ptl *ptl; + + ptl = READ_ONCE(rqst->packet.ptl); + return likely(ptl) ? to_ssh_rtl(ptl, ptl) : NULL; +} + +int ssh_rtl_submit(struct ssh_rtl *rtl, struct ssh_request *rqst); +bool ssh_rtl_cancel(struct ssh_request *rqst, bool pending); + +int ssh_rtl_init(struct ssh_rtl *rtl, struct serdev_device *serdev, + const struct ssh_rtl_ops *ops); + +int ssh_rtl_start(struct ssh_rtl *rtl); +int ssh_rtl_flush(struct ssh_rtl *rtl, unsigned long timeout); +void ssh_rtl_shutdown(struct ssh_rtl *rtl); +void ssh_rtl_destroy(struct ssh_rtl *rtl); + +int ssh_request_init(struct ssh_request *rqst, enum ssam_request_flags flags, + const struct ssh_request_ops *ops); + +#endif /* _SURFACE_AGGREGATOR_SSH_REQUEST_LAYER_H */ |