diff options
| author | Russ Weight <russell.h.weight@intel.com> | 2022-04-22 00:22:00 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-04-26 13:34:28 +0300 |
| commit | 97730bbb242cde22b7140acd202ffd88823886c9 (patch) | |
| tree | b09e50663744488f3b91ed37a764837a06355bb2 /Documentation/ABI | |
| parent | e0c11a8b985137aebf4bcd07cd957b80ac23924d (diff) | |
| download | linux-97730bbb242cde22b7140acd202ffd88823886c9.tar.xz | |
firmware_loader: Add firmware-upload support
Extend the firmware subsystem to support a persistent sysfs interface that
userspace may use to initiate a firmware update. For example, FPGA based
PCIe cards load firmware and FPGA images from local FLASH when the card
boots. The images in FLASH may be updated with new images provided by the
user at his/her convenience.
A device driver may call firmware_upload_register() to expose persistent
"loading" and "data" sysfs files. These files are used in the same way as
the fallback sysfs "loading" and "data" files. When 0 is written to
"loading" to complete the write of firmware data, the data is transferred
to the lower-level driver using pre-registered call-back functions. The
data transfer is done in the context of a kernel worker thread.
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Reviewed-by: Tianfei zhang <tianfei.zhang@intel.com>
Tested-by: Matthew Gerlach <matthew.gerlach@linux.intel.com>
Signed-off-by: Russ Weight <russell.h.weight@intel.com>
Link: https://lore.kernel.org/r/20220421212204.36052-5-russell.h.weight@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'Documentation/ABI')
| -rw-r--r-- | Documentation/ABI/testing/sysfs-class-firmware | 32 |
1 files changed, 32 insertions, 0 deletions
diff --git a/Documentation/ABI/testing/sysfs-class-firmware b/Documentation/ABI/testing/sysfs-class-firmware new file mode 100644 index 000000000000..18336c23b70d --- /dev/null +++ b/Documentation/ABI/testing/sysfs-class-firmware @@ -0,0 +1,32 @@ +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/.../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/.../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. |