diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-firmware | 77 | ||||
| -rw-r--r-- | Documentation/ABI/testing/sysfs-devices-physical_location | 42 | ||||
| -rw-r--r-- | Documentation/admin-guide/kernel-parameters.txt | 11 | ||||
| -rw-r--r-- | Documentation/driver-api/firmware/fw_upload.rst | 126 | ||||
| -rw-r--r-- | Documentation/driver-api/firmware/index.rst | 1 |
5 files changed, 254 insertions, 3 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-firmware b/Documentation/ABI/testing/sysfs-class-firmware new file mode 100644 index 000000000000..978d3d500400 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-firmware @@ -0,0 +1,77 @@ +What: /sys/class/firmware/.../data +Date: July 2022 +KernelVersion: 5.19 +Contact: Russ Weight <russell.h.weight@intel.com> +Description: The data sysfs file is used for firmware-fallback and for + firmware uploads. Cat a firmware image to this sysfs file + after you echo 1 to the loading sysfs file. When the firmware + image write is complete, echo 0 to the loading sysfs file. This + sequence will signal the completion of the firmware write and + signal the lower-level driver that the firmware data is + available. + +What: /sys/class/firmware/.../cancel +Date: July 2022 +KernelVersion: 5.19 +Contact: Russ Weight <russell.h.weight@intel.com> +Description: Write-only. For firmware uploads, write a "1" to this file to + request that the transfer of firmware data to the lower-level + device be canceled. This request will be rejected (EBUSY) if + the update cannot be canceled (e.g. a FLASH write is in + progress) or (ENODEV) if there is no firmware update in progress. + +What: /sys/class/firmware/.../error +Date: July 2022 +KernelVersion: 5.19 +Contact: Russ Weight <russell.h.weight@intel.com> +Description: Read-only. Returns a string describing a failed firmware + upload. This string will be in the form of <STATUS>:<ERROR>, + where <STATUS> will be one of the status strings described + for the status sysfs file and <ERROR> will be one of the + following: "hw-error", "timeout", "user-abort", "device-busy", + "invalid-file-size", "read-write-error", "flash-wearout". The + error sysfs file is only meaningful when the current firmware + upload status is "idle". If this file is read while a firmware + transfer is in progress, then the read will fail with EBUSY. + +What: /sys/class/firmware/.../loading +Date: July 2022 +KernelVersion: 5.19 +Contact: Russ Weight <russell.h.weight@intel.com> +Description: The loading sysfs file is used for both firmware-fallback and + for firmware uploads. Echo 1 onto the loading file to indicate + you are writing a firmware file to the data sysfs node. Echo + -1 onto this file to abort the data write or echo 0 onto this + file to indicate that the write is complete. For firmware + uploads, the zero value also triggers the transfer of the + firmware data to the lower-level device driver. + +What: /sys/class/firmware/.../remaining_size +Date: July 2022 +KernelVersion: 5.19 +Contact: Russ Weight <russell.h.weight@intel.com> +Description: Read-only. For firmware upload, this file contains the size + of the firmware data that remains to be transferred to the + lower-level device driver. The size value is initialized to + the full size of the firmware image that was previously + written to the data sysfs file. This value is periodically + updated during the "transferring" phase of the firmware + upload. + Format: "%u". + +What: /sys/class/firmware/.../status +Date: July 2022 +KernelVersion: 5.19 +Contact: Russ Weight <russell.h.weight@intel.com> +Description: Read-only. Returns a string describing the current status of + a firmware upload. The string will be one of the following: + idle, "receiving", "preparing", "transferring", "programming". + +What: /sys/class/firmware/.../timeout +Date: July 2022 +KernelVersion: 5.19 +Contact: Russ Weight <russell.h.weight@intel.com> +Description: This file supports the timeout mechanism for firmware + fallback. This file has no affect on firmware uploads. For + more information on timeouts please see the documentation + for firmware fallback. diff --git a/Documentation/ABI/testing/sysfs-devices-physical_location b/Documentation/ABI/testing/sysfs-devices-physical_location new file mode 100644 index 000000000000..202324b87083 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-devices-physical_location @@ -0,0 +1,42 @@ +What: /sys/devices/.../physical_location +Date: March 2022 +Contact: Won Chung <wonchung@google.com> +Description: + This directory contains information on physical location of + the device connection point with respect to the system's + housing. + +What: /sys/devices/.../physical_location/panel +Date: March 2022 +Contact: Won Chung <wonchung@google.com> +Description: + Describes which panel surface of the system’s housing the + device connection point resides on. + +What: /sys/devices/.../physical_location/vertical_position +Date: March 2022 +Contact: Won Chung <wonchung@google.com> +Description: + Describes vertical position of the device connection point on + the panel surface. + +What: /sys/devices/.../physical_location/horizontal_position +Date: March 2022 +Contact: Won Chung <wonchung@google.com> +Description: + Describes horizontal position of the device connection point on + the panel surface. + +What: /sys/devices/.../physical_location/dock +Date: March 2022 +Contact: Won Chung <wonchung@google.com> +Description: + "Yes" if the device connection point resides in a docking + station or a port replicator. "No" otherwise. + +What: /sys/devices/.../physical_location/lid +Date: March 2022 +Contact: Won Chung <wonchung@google.com> +Description: + "Yes" if the device connection point resides on the lid of + laptop system. "No" otherwise. diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt index 710b52d87bdd..8090130b544b 100644 --- a/Documentation/admin-guide/kernel-parameters.txt +++ b/Documentation/admin-guide/kernel-parameters.txt @@ -979,8 +979,10 @@ [KNL] Debugging option to set a timeout in seconds for deferred probe to give up waiting on dependencies to probe. Only specific dependencies (subsystems or - drivers) that have opted in will be ignored. A timeout of 0 - will timeout at the end of initcalls. This option will also + drivers) that have opted in will be ignored. A timeout + of 0 will timeout at the end of initcalls. If the time + out hasn't expired, it'll be restarted by each + successful driver registration. This option will also dump out devices still on the deferred probe list after retrying. @@ -1101,7 +1103,10 @@ driver later using sysfs. driver_async_probe= [KNL] - List of driver names to be probed asynchronously. + List of driver names to be probed asynchronously. * + matches with all driver names. If * is specified, the + rest of the listed driver names are those that will NOT + match the *. Format: <driver_name1>,<driver_name2>... drm.edid_firmware=[<connector>:]<file>[,[<connector>:]<file>] diff --git a/Documentation/driver-api/firmware/fw_upload.rst b/Documentation/driver-api/firmware/fw_upload.rst new file mode 100644 index 000000000000..76922591e446 --- /dev/null +++ b/Documentation/driver-api/firmware/fw_upload.rst @@ -0,0 +1,126 @@ +.. SPDX-License-Identifier: GPL-2.0 + +=================== +Firmware Upload API +=================== + +A device driver that registers with the firmware loader will expose +persistent sysfs nodes to enable users to initiate firmware updates for +that device. It is the responsibility of the device driver and/or the +device itself to perform any validation on the data received. Firmware +upload uses the same *loading* and *data* sysfs files described in the +documentation for firmware fallback. It also adds additional sysfs files +to provide status on the transfer of the firmware image to the device. + +Register for firmware upload +============================ + +A device driver registers for firmware upload by calling +firmware_upload_register(). Among the parameter list is a name to +identify the device under /sys/class/firmware. A user may initiate a +firmware upload by echoing a 1 to the *loading* sysfs file for the target +device. Next, the user writes the firmware image to the *data* sysfs +file. After writing the firmware data, the user echos 0 to the *loading* +sysfs file to signal completion. Echoing 0 to *loading* also triggers the +transfer of the firmware to the lower-lever device driver in the context +of a kernel worker thread. + +To use the firmware upload API, write a driver that implements a set of +ops. The probe function calls firmware_upload_register() and the remove +function calls firmware_upload_unregister() such as:: + + static const struct fw_upload_ops m10bmc_ops = { + .prepare = m10bmc_sec_prepare, + .write = m10bmc_sec_write, + .poll_complete = m10bmc_sec_poll_complete, + .cancel = m10bmc_sec_cancel, + .cleanup = m10bmc_sec_cleanup, + }; + + static int m10bmc_sec_probe(struct platform_device *pdev) + { + const char *fw_name, *truncate; + struct m10bmc_sec *sec; + struct fw_upload *fwl; + unsigned int len; + + sec = devm_kzalloc(&pdev->dev, sizeof(*sec), GFP_KERNEL); + if (!sec) + return -ENOMEM; + + sec->dev = &pdev->dev; + sec->m10bmc = dev_get_drvdata(pdev->dev.parent); + dev_set_drvdata(&pdev->dev, sec); + + fw_name = dev_name(sec->dev); + truncate = strstr(fw_name, ".auto"); + len = (truncate) ? truncate - fw_name : strlen(fw_name); + sec->fw_name = kmemdup_nul(fw_name, len, GFP_KERNEL); + + fwl = firmware_upload_register(sec->dev, sec->fw_name, &m10bmc_ops, sec); + if (IS_ERR(fwl)) { + dev_err(sec->dev, "Firmware Upload driver failed to start\n"); + kfree(sec->fw_name); + return PTR_ERR(fwl); + } + + sec->fwl = fwl; + return 0; + } + + static int m10bmc_sec_remove(struct platform_device *pdev) + { + struct m10bmc_sec *sec = dev_get_drvdata(&pdev->dev); + + firmware_upload_unregister(sec->fwl); + kfree(sec->fw_name); + return 0; + } + +firmware_upload_register +------------------------ +.. kernel-doc:: drivers/base/firmware_loader/sysfs_upload.c + :identifiers: firmware_upload_register + +firmware_upload_unregister +-------------------------- +.. kernel-doc:: drivers/base/firmware_loader/sysfs_upload.c + :identifiers: firmware_upload_unregister + +Firmware Upload Ops +------------------- +.. kernel-doc:: include/linux/firmware.h + :identifiers: fw_upload_ops + +Firmware Upload Progress Codes +------------------------------ +The following progress codes are used internally by the firmware loader. +Corresponding strings are reported through the status sysfs node that +is described below and are documented in the ABI documentation. + +.. kernel-doc:: drivers/base/firmware_loader/sysfs_upload.h + :identifiers: fw_upload_prog + +Firmware Upload Error Codes +--------------------------- +The following error codes may be returned by the driver ops in case of +failure: + +.. kernel-doc:: include/linux/firmware.h + :identifiers: fw_upload_err + +Sysfs Attributes +================ + +In addition to the *loading* and *data* sysfs files, there are additional +sysfs files to monitor the status of the data transfer to the target +device and to determine the final pass/fail status of the transfer. +Depending on the device and the size of the firmware image, a firmware +update could take milliseconds or minutes. + +The additional sysfs files are: + +* status - provides an indication of the progress of a firmware update +* error - provides error information for a failed firmware update +* remaining_size - tracks the data transfer portion of an update +* cancel - echo 1 to this file to cancel the update diff --git a/Documentation/driver-api/firmware/index.rst b/Documentation/driver-api/firmware/index.rst index 57415d657173..9d2c19dc8e36 100644 --- a/Documentation/driver-api/firmware/index.rst +++ b/Documentation/driver-api/firmware/index.rst @@ -8,6 +8,7 @@ Linux Firmware API core efi/index request_firmware + fw_upload other_interfaces .. only:: subproject and html |