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Message-ID: <ff04d11a-f5b5-6561-ef32-f85ccfe14f21@quicinc.com>
Date: Thu, 11 Apr 2024 08:41:29 -0600
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Subject: Re: [PATCH v2 1/2] bus: mhi: host: Add sysfs entry to force device to
 enter EDL
Content-Language: en-US
To: Qiang Yu <quic_qianyu@quicinc.com>, <mani@kernel.org>
CC: <mhi@lists.linux.dev>, <linux-arm-msm@vger.kernel.org>,
        <linux-kernel@vger.kernel.org>, <quic_cang@quicinc.com>,
        <quic_mrana@quicinc.com>
References: <1712805329-46158-1-git-send-email-quic_qianyu@quicinc.com>
 <1712805329-46158-2-git-send-email-quic_qianyu@quicinc.com>
From: Jeffrey Hugo <quic_jhugo@quicinc.com>
In-Reply-To: <1712805329-46158-2-git-send-email-quic_qianyu@quicinc.com>
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On 4/10/2024 9:15 PM, 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@quicinc.com>
> ---
>   drivers/bus/mhi/host/init.c | 35 +++++++++++++++++++++++++++++++++++
>   include/linux/mhi.h         |  1 +

No update to Documentation/ABI/stable/sysfs-bus-mhi ?

>   2 files changed, 36 insertions(+)
> 
> diff --git a/drivers/bus/mhi/host/init.c b/drivers/bus/mhi/host/init.c
> index 44f9349..333ac94 100644
> --- a/drivers/bus/mhi/host/init.c
> +++ b/drivers/bus/mhi/host/init.c
> @@ -127,6 +127,32 @@ static ssize_t soc_reset_store(struct device *dev,
>   }
>   static DEVICE_ATTR_WO(soc_reset);
>   
> +static ssize_t force_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) {
> +		dev_err(dev, "Could not parse string: %d\n", ret);
> +		return ret;
> +	}
> +
> +	if (!val)
> +		return count;
> +
> +	ret = mhi_cntrl->edl_trigger(mhi_cntrl);
> +	if (ret)
> +		return ret;
> +
> +	return count;
> +}
> +static DEVICE_ATTR_WO(force_edl);
> +
>   static struct attribute *mhi_dev_attrs[] = {
>   	&dev_attr_serial_number.attr,
>   	&dev_attr_oem_pk_hash.attr,
> @@ -1018,6 +1044,12 @@ 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_force_edl.attr);
> +		if (ret)
> +			goto err_release_dev;
> +	}
> +
>   	mhi_cntrl->mhi_dev = mhi_dev;
>   
>   	mhi_create_debugfs(mhi_cntrl);
> @@ -1051,6 +1083,9 @@ 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_force_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..8db56d7 100644
> --- a/include/linux/mhi.h
> +++ b/include/linux/mhi.h
> @@ -435,6 +435,7 @@ 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);

No update to the documentation for this struct?