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Subject: Re: [PATCH V7 2/2] soc: qcom: aoss: Add debugfs entry
To:     Bjorn Andersson <bjorn.andersson@linaro.org>
Cc:     swboyd@chromium.org, clew@codeaurora.org, sibis@codeaurora.org,
        linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-remoteproc@vger.kernel.org, Andy Gross <agross@kernel.org>
References: <1630323451-7160-1-git-send-email-deesin@codeaurora.org>
 <1630323451-7160-3-git-send-email-deesin@codeaurora.org>
 <YS1nSP8kziOPaDld@yoga>
From:   Deepak Kumar Singh <deesin@codeaurora.org>
Message-ID: <6b1c4368-72e2-79e4-37c5-d333bb6bec5d@codeaurora.org>
Date:   Tue, 31 Aug 2021 20:03:42 +0530
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On 8/31/2021 4:48 AM, Bjorn Andersson wrote:
> On Mon 30 Aug 06:37 CDT 2021, Deepak Kumar Singh wrote:
>
>> Some user space clients may require to change power states of various
>> parts of hardware. Add a debugfs node for qmp so messages can be sent
>> to aoss from user space.
>>
> I think this could be a useful tool while testing and developing client
> drivers or perhaps during bringup of new platforms.
>
> But your new commit message doesn't sound right, given that debugfs
> isn't mounted in your production builds.
>
> Regards,
> Bjorn
Updated commit message in V8.
>
>> Signed-off-by: Chris Lew <clew@codeaurora.org>
>> Signed-off-by: Deepak Kumar Singh <deesin@codeaurora.org>
>> ---
>>   drivers/soc/qcom/qcom_aoss.c | 32 ++++++++++++++++++++++++++++++++
>>   1 file changed, 32 insertions(+)
>>
>> diff --git a/drivers/soc/qcom/qcom_aoss.c b/drivers/soc/qcom/qcom_aoss.c
>> index bf0a6280..4cd8670 100644
>> --- a/drivers/soc/qcom/qcom_aoss.c
>> +++ b/drivers/soc/qcom/qcom_aoss.c
>> @@ -4,6 +4,7 @@
>>    */
>>   #include <dt-bindings/power/qcom-aoss-qmp.h>
>>   #include <linux/clk-provider.h>
>> +#include <linux/debugfs.h>
>>   #include <linux/interrupt.h>
>>   #include <linux/io.h>
>>   #include <linux/mailbox_client.h>
>> @@ -86,6 +87,7 @@ struct qmp {
>>   	struct clk_hw qdss_clk;
>>   	struct genpd_onecell_data pd_data;
>>   	struct qmp_cooling_device *cooling_devs;
>> +	struct dentry *debugfs_file;
>>   };
>>   
>>   struct qmp_pd {
>> @@ -566,6 +568,31 @@ void qmp_put(struct qmp *qmp)
>>   }
>>   EXPORT_SYMBOL(qmp_put);
>>   
>> +static ssize_t aoss_dbg_write(struct file *file, const char __user *userstr,
>> +			      size_t len, loff_t *pos)
>> +{
>> +	struct qmp *qmp = file->private_data;
>> +	char buf[QMP_MSG_LEN] = {};
>> +	int ret;
>> +
>> +	if (!len || len >= QMP_MSG_LEN)
>> +		return -EINVAL;
>> +
>> +	ret  = copy_from_user(buf, userstr, len);
>> +	if (ret) {
>> +		return -EFAULT;
>> +	}
>> +
>> +	ret = qmp_send(qmp, buf, QMP_MSG_LEN);
>> +
>> +	return ret ? ret : len;
>> +}
>> +
>> +static const struct file_operations aoss_dbg_fops = {
>> +	.open = simple_open,
>> +	.write = aoss_dbg_write,
>> +};
>> +
>>   static int qmp_probe(struct platform_device *pdev)
>>   {
>>   	struct resource *res;
>> @@ -620,6 +647,9 @@ static int qmp_probe(struct platform_device *pdev)
>>   
>>   	platform_set_drvdata(pdev, qmp);
>>   
>> +	qmp->debugfs_file = debugfs_create_file("aoss_send_message", 0220, NULL,
>> +						qmp, &aoss_dbg_fops);
>> +
>>   	return 0;
>>   
>>   err_remove_qdss_clk:
>> @@ -636,6 +666,8 @@ static int qmp_remove(struct platform_device *pdev)
>>   {
>>   	struct qmp *qmp = platform_get_drvdata(pdev);
>>   
>> +	debugfs_remove(qmp->debugfs_file);
>> +
>>   	qmp_qdss_clk_remove(qmp);
>>   	qmp_pd_remove(qmp);
>>   	qmp_cooling_devices_remove(qmp);
>> -- 
>> The Qualcomm Innovation Center, Inc. is a member of the Code Aurora Forum,
>> a Linux Foundation Collaborative Project
>>