[PATCH 1/2] usb: mtu3: add a vbus debugfs interface

[PATCH 1/2] usb: mtu3: add a vbus debugfs interface

[Chunfeng Yun]

Provides a new vbus debugfs interface used to turn on/off vbus
regulator, it also can be used to get/put reference count of
vbus, due to sometimes we need keep it alive when manually switch
mtu3 to device mode.

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
 drivers/usb/mtu3/mtu3_dr.c |   75 +++++++++++++++++++++++++++++++++++++++-----
 1 file changed, 67 insertions(+), 8 deletions(-)

diff --git a/drivers/usb/mtu3/mtu3_dr.c b/drivers/usb/mtu3/mtu3_dr.c
index 11a0d3b..6c75916 100644
--- a/drivers/usb/mtu3/mtu3_dr.c
+++ b/drivers/usb/mtu3/mtu3_dr.c
@@ -322,23 +322,82 @@ static ssize_t ssusb_mode_write(struct file *file,
 	.release = single_release,
 };
 
-static void ssusb_debugfs_init(struct ssusb_mtk *ssusb)
+static int ssusb_vbus_show(struct seq_file *sf, void *unused)
+{
+	struct ssusb_mtk *ssusb = sf->private;
+	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
+
+	seq_printf(sf, "vbus state: %s\n(echo on/off)\n",
+		regulator_is_enabled(otg_sx->vbus) ? "on" : "off");
+
+	return 0;
+}
+
+static int ssusb_vbus_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ssusb_vbus_show, inode->i_private);
+}
+
+static ssize_t ssusb_vbus_write(struct file *file,
+	const char __user *ubuf, size_t count, loff_t *ppos)
+{
+	struct seq_file *sf = file->private_data;
+	struct ssusb_mtk *ssusb = sf->private;
+	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
+	char buf[16];
+
+	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
+		return -EFAULT;
+
+	if (!strncmp(buf, "on", 2)) {
+		ssusb_set_vbus(otg_sx, 1);
+	} else if (!strncmp(buf, "off", 3)) {
+		ssusb_set_vbus(otg_sx, 0);
+	} else {
+		dev_err(ssusb->dev, "wrong setting\n");
+		return -EINVAL;
+	}
+
+	return count;
+}
+
+static const struct file_operations ssusb_vbus_fops = {
+	.open = ssusb_vbus_open,
+	.write = ssusb_vbus_write,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+static int ssusb_debugfs_init(struct ssusb_mtk *ssusb)
 {
 	struct dentry *root;
 	struct dentry *file;
 
 	root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
 	if (IS_ERR_OR_NULL(root)) {
-		if (!root)
-			dev_err(ssusb->dev, "create debugfs root failed\n");
-		return;
+		dev_err(ssusb->dev, "create debugfs root failed\n");
+		goto err_dbgfs;
 	}
 	ssusb->dbgfs_root = root;
 
-	file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
-			ssusb, &ssusb_mode_fops);
-	if (!file)
-		dev_dbg(ssusb->dev, "create debugfs mode failed\n");
+	file = debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
+	if (!file) {
+		dev_err(ssusb->dev, "create debugfs mode failed\n");
+		goto err_dbgfs;
+	}
+
+	file = debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
+	if (!file) {
+		dev_err(ssusb->dev, "create debugfs vbus failed\n");
+		goto err_dbgfs;
+	}
+
+	return 0;
+
+err_dbgfs:
+	debugfs_remove_recursive(ssusb->dbgfs_root);
+	return -ENOMEM;
 }
 
 static void ssusb_debugfs_exit(struct ssusb_mtk *ssusb)
-- 
1.7.9.5

[PATCH 2/2] MAINTAINERS: add entry for mediatek usb3 DRD IP driver

[Chunfeng Yun]

Add myself as maintainer of MediaTek USB3 DRD IP driver

Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
---
 MAINTAINERS |    7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/MAINTAINERS b/MAINTAINERS
index 205d397..0f0bcc7 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -8472,6 +8472,13 @@ M:      Sean Wang <sean.wang@mediatek.com>
 S:      Maintained
 F:      drivers/char/hw_random/mtk-rng.c
 
+MEDIATEK USB3 DRD IP DRIVER
+M:	Chunfeng Yun <chunfeng.yun@mediatek.com>
+L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
+L:	linux-mediatek@lists.infradead.org (moderated for non-subscribers)
+S:	Maintained
+F:	drivers/usb/mtu3/
+
 MEGACHIPS STDPXXXX-GE-B850V3-FW LVDS/DP++ BRIDGES
 M:	Peter Senna Tschudin <peter.senna@collabora.com>
 M:	Martin Donnelly <martin.donnelly@ge.com>
-- 
1.7.9.5

Re: [PATCH 2/2] MAINTAINERS: add entry for mediatek usb3 DRD IP driver

[Felipe Balbi]

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Hi,

Chunfeng Yun <chunfeng.yun@mediatek.com> writes:
> Add myself as maintainer of MediaTek USB3 DRD IP driver
>
> Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> ---
>  MAINTAINERS |    7 +++++++
>  1 file changed, 7 insertions(+)
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 205d397..0f0bcc7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -8472,6 +8472,13 @@ M:      Sean Wang <sean.wang@mediatek.com>
>  S:      Maintained
>  F:      drivers/char/hw_random/mtk-rng.c
>  
> +MEDIATEK USB3 DRD IP DRIVER
> +M:	Chunfeng Yun <chunfeng.yun@mediatek.com>
> +L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
> +L:	linux-mediatek@lists.infradead.org (moderated for non-subscribers)

everything USB should go to linux-usb too.

-- 
balbi

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Re: [PATCH 2/2] MAINTAINERS: add entry for mediatek usb3 DRD IP driver

[Chunfeng Yun]

On Thu, 2017-08-03 at 12:23 +0300, Felipe Balbi wrote:
> Hi,
> 
> Chunfeng Yun <chunfeng.yun@mediatek.com> writes:
> > Add myself as maintainer of MediaTek USB3 DRD IP driver
> >
> > Signed-off-by: Chunfeng Yun <chunfeng.yun@mediatek.com>
> > ---
> >  MAINTAINERS |    7 +++++++
> >  1 file changed, 7 insertions(+)
> >
> > diff --git a/MAINTAINERS b/MAINTAINERS
> > index 205d397..0f0bcc7 100644
> > --- a/MAINTAINERS
> > +++ b/MAINTAINERS
> > @@ -8472,6 +8472,13 @@ M:      Sean Wang <sean.wang@mediatek.com>
> >  S:      Maintained
> >  F:      drivers/char/hw_random/mtk-rng.c
> >  
> > +MEDIATEK USB3 DRD IP DRIVER
> > +M:	Chunfeng Yun <chunfeng.yun@mediatek.com>
> > +L:	linux-arm-kernel@lists.infradead.org (moderated for non-subscribers)
> > +L:	linux-mediatek@lists.infradead.org (moderated for non-subscribers)
> 
> everything USB should go to linux-usb too.
Ok, I'll add it, thanks
> 

Re: [PATCH 1/2] usb: mtu3: add a vbus debugfs interface

[Greg Kroah-Hartman]

On Thu, Aug 03, 2017 at 04:37:18PM +0800, Chunfeng Yun wrote:
> +static ssize_t ssusb_vbus_write(struct file *file,
> +	const char __user *ubuf, size_t count, loff_t *ppos)
> +{
> +	struct seq_file *sf = file->private_data;
> +	struct ssusb_mtk *ssusb = sf->private;
> +	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
> +	char buf[16];
> +
> +	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
> +		return -EFAULT;
> +
> +	if (!strncmp(buf, "on", 2)) {
> +		ssusb_set_vbus(otg_sx, 1);
> +	} else if (!strncmp(buf, "off", 3)) {
> +		ssusb_set_vbus(otg_sx, 0);

kstrtobool() is better to use here.

> +static int ssusb_debugfs_init(struct ssusb_mtk *ssusb)
>  {
>  	struct dentry *root;
>  	struct dentry *file;
>  
>  	root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
>  	if (IS_ERR_OR_NULL(root)) {

That test is wrong, you should never need to care about the return value
of a debugfs call.  You can always just use it in your next call (if it
is a dentry *), or just ignore it.

> -		if (!root)
> -			dev_err(ssusb->dev, "create debugfs root failed\n");
> -		return;
> +		dev_err(ssusb->dev, "create debugfs root failed\n");
> +		goto err_dbgfs;
>  	}
>  	ssusb->dbgfs_root = root;
>  
> -	file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
> -			ssusb, &ssusb_mode_fops);
> -	if (!file)
> -		dev_dbg(ssusb->dev, "create debugfs mode failed\n");
> +	file = debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
> +	if (!file) {
> +		dev_err(ssusb->dev, "create debugfs mode failed\n");

Same here, do not care, as it does not matter.  Actually, you don't even
need to keep the file pointer around, right?

> +		goto err_dbgfs;
> +	}
> +
> +	file = debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
> +	if (!file) {

Same here, you don't care if debugfs fails or not, it should never
affect your code flow.

And don't you need to remove the directory when your module/hardware is
removed?  I don't see that happening here as you are not saving root off
anywhere.

thanks,

greg k-h

Re: [PATCH 1/2] usb: mtu3: add a vbus debugfs interface

[Greg Kroah-Hartman]

On Thu, Aug 03, 2017 at 09:00:57AM -0700, Greg Kroah-Hartman wrote:
> On Thu, Aug 03, 2017 at 04:37:18PM +0800, Chunfeng Yun wrote:
> > +static ssize_t ssusb_vbus_write(struct file *file,
> > +	const char __user *ubuf, size_t count, loff_t *ppos)
> > +{
> > +	struct seq_file *sf = file->private_data;
> > +	struct ssusb_mtk *ssusb = sf->private;
> > +	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
> > +	char buf[16];
> > +
> > +	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
> > +		return -EFAULT;
> > +
> > +	if (!strncmp(buf, "on", 2)) {
> > +		ssusb_set_vbus(otg_sx, 1);
> > +	} else if (!strncmp(buf, "off", 3)) {
> > +		ssusb_set_vbus(otg_sx, 0);
> 
> kstrtobool() is better to use here.
> 
> > +static int ssusb_debugfs_init(struct ssusb_mtk *ssusb)
> >  {
> >  	struct dentry *root;
> >  	struct dentry *file;
> >  
> >  	root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
> >  	if (IS_ERR_OR_NULL(root)) {
> 
> That test is wrong, you should never need to care about the return value
> of a debugfs call.  You can always just use it in your next call (if it
> is a dentry *), or just ignore it.
> 
> > -		if (!root)
> > -			dev_err(ssusb->dev, "create debugfs root failed\n");
> > -		return;
> > +		dev_err(ssusb->dev, "create debugfs root failed\n");
> > +		goto err_dbgfs;
> >  	}
> >  	ssusb->dbgfs_root = root;
> >  
> > -	file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
> > -			ssusb, &ssusb_mode_fops);
> > -	if (!file)
> > -		dev_dbg(ssusb->dev, "create debugfs mode failed\n");
> > +	file = debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
> > +	if (!file) {
> > +		dev_err(ssusb->dev, "create debugfs mode failed\n");
> 
> Same here, do not care, as it does not matter.  Actually, you don't even
> need to keep the file pointer around, right?
> 
> > +		goto err_dbgfs;
> > +	}
> > +
> > +	file = debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
> > +	if (!file) {
> 
> Same here, you don't care if debugfs fails or not, it should never
> affect your code flow.
> 
> And don't you need to remove the directory when your module/hardware is
> removed?  I don't see that happening here as you are not saving root off
> anywhere.

Oh nevermind, you do save it, sorry for the noise...

greg k-h

Re: [PATCH 1/2] usb: mtu3: add a vbus debugfs interface

[Chunfeng Yun]

On Thu, 2017-08-03 at 09:01 -0700, Greg Kroah-Hartman wrote:
> On Thu, Aug 03, 2017 at 09:00:57AM -0700, Greg Kroah-Hartman wrote:
> > On Thu, Aug 03, 2017 at 04:37:18PM +0800, Chunfeng Yun wrote:
> > > +static ssize_t ssusb_vbus_write(struct file *file,
> > > +	const char __user *ubuf, size_t count, loff_t *ppos)
> > > +{
> > > +	struct seq_file *sf = file->private_data;
> > > +	struct ssusb_mtk *ssusb = sf->private;
> > > +	struct otg_switch_mtk *otg_sx = &ssusb->otg_switch;
> > > +	char buf[16];
> > > +
> > > +	if (copy_from_user(&buf, ubuf, min_t(size_t, sizeof(buf) - 1, count)))
> > > +		return -EFAULT;
> > > +
> > > +	if (!strncmp(buf, "on", 2)) {
> > > +		ssusb_set_vbus(otg_sx, 1);
> > > +	} else if (!strncmp(buf, "off", 3)) {
> > > +		ssusb_set_vbus(otg_sx, 0);
> > 
> > kstrtobool() is better to use here.
Ok
> > 
> > > +static int ssusb_debugfs_init(struct ssusb_mtk *ssusb)
> > >  {
> > >  	struct dentry *root;
> > >  	struct dentry *file;
> > >  
> > >  	root = debugfs_create_dir(dev_name(ssusb->dev), usb_debug_root);
> > >  	if (IS_ERR_OR_NULL(root)) {
> > 
> > That test is wrong, you should never need to care about the return value
> > of a debugfs call.  You can always just use it in your next call (if it
> > is a dentry *), or just ignore it.
Ok, I'll just test NULL pointer, and ignore other ERROR value
> > 
> > > -		if (!root)
> > > -			dev_err(ssusb->dev, "create debugfs root failed\n");
> > > -		return;
> > > +		dev_err(ssusb->dev, "create debugfs root failed\n");
> > > +		goto err_dbgfs;
> > >  	}
> > >  	ssusb->dbgfs_root = root;
> > >  
> > > -	file = debugfs_create_file("mode", S_IRUGO | S_IWUSR, root,
> > > -			ssusb, &ssusb_mode_fops);
> > > -	if (!file)
> > > -		dev_dbg(ssusb->dev, "create debugfs mode failed\n");
> > > +	file = debugfs_create_file("mode", 0644, root, ssusb, &ssusb_mode_fops);
> > > +	if (!file) {
> > > +		dev_err(ssusb->dev, "create debugfs mode failed\n");
> > 
> > Same here, do not care, as it does not matter.  Actually, you don't even
> > need to keep the file pointer around, right?
Yes, you are right
> > 
> > > +		goto err_dbgfs;
> > > +	}
> > > +
> > > +	file = debugfs_create_file("vbus", 0644, root, ssusb, &ssusb_vbus_fops);
> > > +	if (!file) {
> > 
> > Same here, you don't care if debugfs fails or not, it should never
> > affect your code flow.
Ok

Thanks a lot
> > 
> > And don't you need to remove the directory when your module/hardware is
> > removed?  I don't see that happening here as you are not saving root off
> > anywhere.
> 
> Oh nevermind, you do save it, sorry for the noise...
> 
> greg k-h