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Documentation: hid: intel-ish-hid: add section for firmware loading 

Add a section to describe the ISH firmware loading process for Lunar Lake
and later generations.

Signed-off-by: Qianru Huang <qianru.huang@intel.com>
Signed-off-by: Zhang Lixu <lixu.zhang@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.com>
This commit is contained in:
Qianru Huang 2024-05-06 09:30:37 +08:00 committed by Jiri Kosina
parent 806a4c35d7
commit f7ae3091a9
1 changed files with 65 additions and 0 deletions
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65
Documentation/hid/intel-ish-hid.rst
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@ -339,6 +339,71 @@ End to End HID transport Sequence Diagram
| | | |
ISH Firmware Loading from Host Flow
-----------------------------------
Starting from the Lunar Lake generation, the ISH firmware has been divided into two components for better space optimization and increased flexibility. These components include a bootloader that is integrated into the BIOS, and a main firmware that is stored within the operating system's file system.
The process works as follows:
- Initially, the ISHTP driver sends a command, HOST_START_REQ_CMD, to the ISH bootloader. In response, the bootloader sends back a HOST_START_RES_CMD. This response includes the ISHTP_SUPPORT_CAP_LOADER bit. Subsequently, the ISHTP driver checks if this bit is set. If it is, the firmware loading process from the host begins.
- During this process, the ISHTP driver first invokes the request_firmware() function, followed by sending a LOADER_CMD_XFER_QUERY command. Upon receiving a response from the bootloader, the ISHTP driver sends a LOADER_CMD_XFER_FRAGMENT command. After receiving another response, the ISHTP driver sends a LOADER_CMD_START command. The bootloader responds and then proceeds to the Main Firmware.
- After the process concludes, the ISHTP driver calls the release_firmware() function.
For more detailed information, please refer to the flow descriptions provided below:
::
+---------------+ +-----------------+
| ISHTP Driver | | ISH Bootloader |
+---------------+ +-----------------+
| |
|~~~Send HOST_START_REQ_CMD~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
| |
|<--Send HOST_START_RES_CMD(Includes ISHTP_SUPPORT_CAP_LOADER bit)----|
| |
****************************************************************************************
* if ISHTP_SUPPORT_CAP_LOADER bit is set *
****************************************************************************************
| |
|~~~start loading firmware from host process~~~+ |
| | |
|<---------------------------------------------+ |
| |
--------------------------- |
| Call request_firmware() | |
--------------------------- |
| |
|~~~Send LOADER_CMD_XFER_QUERY~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
| |
|<--Send response-----------------------------------------------------|
| |
|~~~Send LOADER_CMD_XFER_FRAGMENT~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
| |
|<--Send response-----------------------------------------------------|
| |
|~~~Send LOADER_CMD_START~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~>|
| |
|<--Send response-----------------------------------------------------|
| |
| |~~~Jump to Main Firmware~~~+
| | |
| |<--------------------------+
| |
--------------------------- |
| Call release_firmware() | |
--------------------------- |
| |
****************************************************************************************
* end if *
****************************************************************************************
| |
+---------------+ +-----------------+
| ISHTP Driver | | ISH Bootloader |
+---------------+ +-----------------+
ISH Debugging
-------------