Re: [PATCH V7 2/2] soc: qcom: aoss: Add debugfs entry

[Deepak Kumar Singh <deesin@xxxxxxxxxxxxxx>]

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@xxxxxxxxxxxxxx>
> > Signed-off-by: Deepak Kumar Singh <deesin@xxxxxxxxxxxxxx>
> > ---
> >   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