linux/Documentation/ABI/stable/sysfs-bus-mhi
Qiang Yu 17553ba8e1 bus: mhi: host: Add sysfs entry to force device to enter EDL
Add sysfs entry to allow users of MHI bus to force device to enter EDL
(Emergency Download) mode to download the device firmware. Since there is
no guarantee that all the devices will support EDL mode, the sysfs entry
is kept as an optional one and will appear only for the supported devices.

Controllers supporting the EDL mode are expected to provide edl_trigger()
callback that puts the device into EDL mode.

Signed-off-by: Qiang Yu <quic_qianyu@quicinc.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
Link: https://lore.kernel.org/r/1713928915-18229-2-git-send-email-quic_qianyu@quicinc.com
[mani: fixed the kernel version and reworded the commit message]
Signed-off-by: Manivannan Sadhasivam <manivannan.sadhasivam@linaro.org>
2024-04-25 20:16:42 +05:30

45 lines
2.1 KiB
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What: /sys/bus/mhi/devices/.../serialnumber
Date: Sept 2020
KernelVersion: 5.10
Contact: mhi@lists.linux.dev
Description: The file holds the serial number of the client device obtained
using a BHI (Boot Host Interface) register read after at least
one attempt to power up the device has been done. If read
without having the device power on at least once, the file will
read all 0's.
Users: Any userspace application or clients interested in device info.
What: /sys/bus/mhi/devices/.../oem_pk_hash
Date: Sept 2020
KernelVersion: 5.10
Contact: mhi@lists.linux.dev
Description: The file holds the OEM PK Hash value of the endpoint device
obtained using a BHI (Boot Host Interface) register read after
at least one attempt to power up the device has been done. If
read without having the device power on at least once, the file
will read all 0's.
Users: Any userspace application or clients interested in device info.
What: /sys/bus/mhi/devices/.../soc_reset
Date: April 2022
KernelVersion: 5.19
Contact: mhi@lists.linux.dev
Description: Initiates a SoC reset on the MHI controller. A SoC reset is
a reset of last resort, and will require a complete re-init.
This can be useful as a method of recovery if the device is
non-responsive, or as a means of loading new firmware as a
system administration task.
What: /sys/bus/mhi/devices/.../trigger_edl
Date: April 2024
KernelVersion: 6.10
Contact: mhi@lists.linux.dev
Description: Writing a non-zero value to this file will force devices to
enter EDL (Emergency Download) mode. This entry only exists for
devices capable of entering the EDL mode using the standard EDL
triggering mechanism defined in the MHI spec v1.2. Once in EDL
mode, the flash programmer image can be downloaded to the
device to enter the flash programmer execution environment.
This can be useful if user wants to use QDL (Qualcomm Download,
which is used to download firmware over EDL) to update firmware.