On Tue, Apr 23, 2024 at 06:33:35PM +0800, Qiang Yu wrote:
> Add sysfs entry to allow users of MHI bus force device to enter EDL.
> Considering that the way to enter EDL mode varies from device to device and
> some devices even do not support EDL. Hence, add a callback edl_trigger in
> mhi controller as part of the sysfs entry to be invoked and MHI core will
> only create EDL sysfs entry for mhi controller that provides edl_trigger
> callback. All of the process a specific device required to enter EDL mode
> can be placed in this callback.
>
> Signed-off-by: Qiang Yu <quic_qianyu@xxxxxxxxxxx>
One nitpick below. But I'll fix it while applying.
Reviewed-by: Manivannan Sadhasivam <manivannan.sadhasivam@xxxxxxxxxx>
> ---
> Documentation/ABI/stable/sysfs-bus-mhi | 13 +++++++++++++
> drivers/bus/mhi/host/init.c | 33 +++++++++++++++++++++++++++++++++
> include/linux/mhi.h | 2 ++
> 3 files changed, 48 insertions(+)
>
> diff --git a/Documentation/ABI/stable/sysfs-bus-mhi b/Documentation/ABI/stable/sysfs-bus-mhi
> index 1a47f9e..b44f467 100644
> --- a/Documentation/ABI/stable/sysfs-bus-mhi
> +++ b/Documentation/ABI/stable/sysfs-bus-mhi
> @@ -29,3 +29,16 @@ Description: Initiates a SoC reset on the MHI controller. A SoC reset is
> 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: 6.9
6.9 is done, now we are working for 6.10 (feature wise).
- Mani
> +Contact: mhi@xxxxxxxxxxxxxxx
> +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.
> diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
> index 44f9349..7104c18 100644
> --- a/drivers/bus/mhi/host/init.c
> +++ b/drivers/bus/mhi/host/init.c
> @@ -127,6 +127,30 @@ static ssize_t soc_reset_store(struct device *dev,
> }
> static DEVICE_ATTR_WO(soc_reset);
>
> +static ssize_t trigger_edl_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct mhi_device *mhi_dev = to_mhi_device(dev);
> + struct mhi_controller *mhi_cntrl = mhi_dev->mhi_cntrl;
> + unsigned long val;
> + int ret;
> +
> + ret = kstrtoul(buf, 10, &val);
> + if (ret < 0)
> + return ret;
> +
> + if (!val)
> + return -EINVAL;
> +
> + ret = mhi_cntrl->edl_trigger(mhi_cntrl);
> + if (ret)
> + return ret;
> +
> + return count;
> +}
> +static DEVICE_ATTR_WO(trigger_edl);
> +
> static struct attribute *mhi_dev_attrs[] = {
> &dev_attr_serial_number.attr,
> &dev_attr_oem_pk_hash.attr,
> @@ -1018,6 +1042,12 @@ int mhi_register_controller(struct mhi_controller *mhi_cntrl,
> if (ret)
> goto err_release_dev;
>
> + if (mhi_cntrl->edl_trigger) {
> + ret = sysfs_create_file(&mhi_dev->dev.kobj, &dev_attr_trigger_edl.attr);
> + if (ret)
> + goto err_release_dev;
> + }
> +
> mhi_cntrl->mhi_dev = mhi_dev;
>
> mhi_create_debugfs(mhi_cntrl);
> @@ -1051,6 +1081,9 @@ void mhi_unregister_controller(struct mhi_controller *mhi_cntrl)
> mhi_deinit_free_irq(mhi_cntrl);
> mhi_destroy_debugfs(mhi_cntrl);
>
> + if (mhi_cntrl->edl_trigger)
> + sysfs_remove_file(&mhi_dev->dev.kobj, &dev_attr_trigger_edl.attr);
> +
> destroy_workqueue(mhi_cntrl->hiprio_wq);
> kfree(mhi_cntrl->mhi_cmd);
> kfree(mhi_cntrl->mhi_event);
> diff --git a/include/linux/mhi.h b/include/linux/mhi.h
> index cde01e1..d968e1a 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -353,6 +353,7 @@ struct mhi_controller_config {
> * @read_reg: Read a MHI register via the physical link (required)
> * @write_reg: Write a MHI register via the physical link (required)
> * @reset: Controller specific reset function (optional)
> + * @edl_trigger: CB function to trigger EDL mode (optional)
> * @buffer_len: Bounce buffer length
> * @index: Index of the MHI controller instance
> * @bounce_buf: Use of bounce buffer
> @@ -435,6 +436,7 @@ struct mhi_controller {
> void (*write_reg)(struct mhi_controller *mhi_cntrl, void __iomem *addr,
> u32 val);
> void (*reset)(struct mhi_controller *mhi_cntrl);
> + int (*edl_trigger)(struct mhi_controller *mhi_cntrl);
>
> size_t buffer_len;
> int index;
> --
> 2.7.4
>
>
--
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