diff mbox series

[RFC,3/3] usb: typec: Expose Product Type VDOs via sysfs

Message ID 20201118150059.3419-4-heikki.krogerus@linux.intel.com
State New
Headers show
Series usb: typec: Product Type time | expand

Commit Message

Heikki Krogerus Nov. 18, 2020, 3 p.m. UTC
From: Prashant Malani <pmalani@chromium.org>

Interim. ABI doc missing.

A PD-capable device can return up to 3 Product Type VDOs as part of its
DiscoverIdentity Response (USB PD Spec, Rev 3.0, Version 2.0, Section
6.4.4.3.1). Add sysfs attribute to expose these to userspace.

Signed-off-by: Prashant Malani <pmalani@chromium.org>
[ heikki: Only one instead of three attribute files ]
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>'
---
 drivers/usb/typec/class.c | 41 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 41 insertions(+)

Comments

Heikki Krogerus Nov. 19, 2020, 12:11 p.m. UTC | #1
On Wed, Nov 18, 2020 at 04:56:57PM +0100, Greg Kroah-Hartman wrote:
> On Wed, Nov 18, 2020 at 06:00:59PM +0300, Heikki Krogerus wrote:

> > From: Prashant Malani <pmalani@chromium.org>

> > 

> > Interim. ABI doc missing.

> > 

> > A PD-capable device can return up to 3 Product Type VDOs as part of its

> > DiscoverIdentity Response (USB PD Spec, Rev 3.0, Version 2.0, Section

> > 6.4.4.3.1). Add sysfs attribute to expose these to userspace.

> > 

> > Signed-off-by: Prashant Malani <pmalani@chromium.org>

> > [ heikki: Only one instead of three attribute files ]

> > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>'

> > ---

> >  drivers/usb/typec/class.c | 41 +++++++++++++++++++++++++++++++++++++++

> >  1 file changed, 41 insertions(+)

> > 

> > diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c

> > index 303f054181ff7..5e135678f5952 100644

> > --- a/drivers/usb/typec/class.c

> > +++ b/drivers/usb/typec/class.c

> > @@ -165,15 +165,55 @@ static ssize_t product_show(struct device *dev, struct device_attribute *attr,

> >  }

> >  static DEVICE_ATTR_RO(product);

> >  

> > +static ssize_t

> > +product_type_vdo_show(struct device *dev, struct device_attribute *attr, char *buf)

> > +{

> > +	struct usb_pd_identity *id = get_pd_identity(dev);

> > +	size_t len = 0;

> > +	int i;

> > +

> > +	for (i = 0; i < 3; i++) {

> > +		if (!id->vdo[i])

> > +			break;

> > +		len += sysfs_emit(buf, "%08x ", id->vdo[i]);

> > +	}

> > +

> > +	buf[len - 1] = '\n';

> > +

> > +	return len;

> > +}

> 

> I don't understand what you are trying to print out here, documentation

> would be helpful :)

> 

> > +static struct device_attribute dev_attr_product_type_vdo = {

> > +	.attr = {

> > +		.name = "product_type",

> > +		.mode = 0444,

> > +	},

> > +	.show = product_type_vdo_show,

> > +};

> 

> DEVICE_ATTR_RO(product_type_vdo)?

> 

> Why are you calling it "product_type" and not with the "vdo"?

> 

> And you have to name it this, there's always __ATTR_RO(), never put a

> mode in "raw" numbers for a sysfs file if at all possible.


Sorry Greg. This is still work-in-progress.

I didn't use the _vdo ending in the file name because the other files
exposing the other parts (VDOs) of the response to the discover
identity don't have it either.


thanks,

-- 
heikki
diff mbox series

Patch

diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index 303f054181ff7..5e135678f5952 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -165,15 +165,55 @@  static ssize_t product_show(struct device *dev, struct device_attribute *attr,
 }
 static DEVICE_ATTR_RO(product);
 
+static ssize_t
+product_type_vdo_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct usb_pd_identity *id = get_pd_identity(dev);
+	size_t len = 0;
+	int i;
+
+	for (i = 0; i < 3; i++) {
+		if (!id->vdo[i])
+			break;
+		len += sysfs_emit(buf, "%08x ", id->vdo[i]);
+	}
+
+	buf[len - 1] = '\n';
+
+	return len;
+}
+
+static struct device_attribute dev_attr_product_type_vdo = {
+	.attr = {
+		.name = "product_type",
+		.mode = 0444,
+	},
+	.show = product_type_vdo_show,
+};
+
+static umode_t
+typec_identity_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
+{
+	struct usb_pd_identity *id = get_pd_identity(kobj_to_dev(kobj));
+
+	if (attr == &dev_attr_product_type_vdo.attr &&
+	    !id->vdo[0])
+		return 0;
+
+	return attr->mode;
+}
+
 static struct attribute *usb_pd_id_attrs[] = {
 	&dev_attr_id_header.attr,
 	&dev_attr_cert_stat.attr,
 	&dev_attr_product.attr,
+	&dev_attr_product_type_vdo.attr,
 	NULL
 };
 
 static const struct attribute_group usb_pd_id_group = {
 	.name = "identity",
+	.is_visible = typec_identity_attr_is_visible,
 	.attrs = usb_pd_id_attrs,
 };
 
@@ -191,6 +231,7 @@  static void typec_product_type_notify(struct device *dev)
 	if (!ptype)
 		return;
 
+	sysfs_notify(&dev->kobj, "identity", "product_type");
 	sysfs_notify(&dev->kobj, NULL, "product_type");
 
 	envp[0] = kasprintf(GFP_KERNEL, "PRODUCT_TYPE=%s", ptype);