diff mbox series

[v3,2/4] usb: typec: Add attribute file showing the USB Modes of the partner

Message ID 20241011124402.3306994-3-heikki.krogerus@linux.intel.com
State Superseded
Headers show
Series usb: typec: USB Modes | expand

Commit Message

Heikki Krogerus Oct. 11, 2024, 12:44 p.m. UTC 
This attribute file shows the supported USB modes (USB 2.0,
USB 3.0 and USB4) of the partner, and the currently active
mode.

The active mode is determined primarily by checking the
speed of the enumerated USB device. When USB Power Delivery
is supported, the active USB mode should be always the mode
that was used with the Enter_USB Message, regardless of the
result of the USB enumeration. The port drivers can
separately assign the mode with a dedicated API.

If USB Power Delivery Identity is supplied for the partner
device, the supported modes are extracted from it.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
---
 Documentation/ABI/testing/sysfs-class-typec |  14 +++
 drivers/usb/typec/class.c                   | 123 +++++++++++++++++++-
 drivers/usb/typec/class.h                   |   2 +
 include/linux/usb/typec.h                   |   5 +
 4 files changed, 140 insertions(+), 4 deletions(-)

Comments

Abhishek Pandit-Subedi Oct. 15, 2024, 4:07 a.m. UTC | #1 
On Fri, Oct 11, 2024 at 7:04 AM Heikki Krogerus
<heikki.krogerus@linux.intel.com> wrote:
>
> On Fri, Oct 11, 2024 at 03:09:57PM +0200, Greg Kroah-Hartman wrote:
> > On Fri, Oct 11, 2024 at 03:44:00PM +0300, Heikki Krogerus wrote:
> > > This attribute file shows the supported USB modes (USB 2.0,
> > > USB 3.0 and USB4) of the partner, and the currently active
> > > mode.
> > >
> > > The active mode is determined primarily by checking the
> > > speed of the enumerated USB device. When USB Power Delivery
> > > is supported, the active USB mode should be always the mode
> > > that was used with the Enter_USB Message, regardless of the
> > > result of the USB enumeration. The port drivers can
> > > separately assign the mode with a dedicated API.
> > >
> > > If USB Power Delivery Identity is supplied for the partner
> > > device, the supported modes are extracted from it.
> > >
> > > Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > ---
> > >  Documentation/ABI/testing/sysfs-class-typec |  14 +++
> > >  drivers/usb/typec/class.c                   | 123 +++++++++++++++++++-
> > >  drivers/usb/typec/class.h                   |   2 +
> > >  include/linux/usb/typec.h                   |   5 +
> > >  4 files changed, 140 insertions(+), 4 deletions(-)
> > >
> > > diff --git a/Documentation/ABI/testing/sysfs-class-typec b/Documentation/ABI/testing/sysfs-class-typec
> > > index 7c307f02d99e..a3afe04b2688 100644
> > > --- a/Documentation/ABI/testing/sysfs-class-typec
> > > +++ b/Documentation/ABI/testing/sysfs-class-typec
> > > @@ -233,6 +233,20 @@ Description:
> > >             directory exists, it will have an attribute file for every VDO
> > >             in Discover Identity command result.
> > >
> > > +What:              /sys/class/typec/<port>-partner/usb_mode
> > > +Date:              February 2024
> >
> > It's later than this :)
>
> Indeed. I'm sorry.
>
> >
> > > +Contact:   Heikki Krogerus <heikki.krogerus@linux.intel.com>
> > > +Description:       The USB Modes that the partner device supports. The active mode
> > > +           is displayed in brackets. The active USB mode can be changed by
> > > +           writing to this file when the port driver is able to send Data
> > > +           Reset Message to the partner. That requires USB Power Delivery
> > > +           contract between the partner and the port.
> > > +
> > > +           Valid values:
> > > +           - usb2 (USB 2.0)
> > > +           - usb3 (USB 3.2)
> > > +           - usb4 (USB4)
> >
> > We should probably add all of this info to 'lsusb' one of these days.
> > I'll add it to my todo list...
> >
> > > +
> > >  USB Type-C cable devices (eg. /sys/class/typec/port0-cable/)
> > >
> > >  Note: Electronically Marked Cables will have a device also for one cable plug
> > > diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
> > > index ea9ee47bb246..a6fedafc9c86 100644
> > > --- a/drivers/usb/typec/class.c
> > > +++ b/drivers/usb/typec/class.c
> > > @@ -618,6 +618,74 @@ EXPORT_SYMBOL_GPL(typec_unregister_altmode);
> > >  /* ------------------------------------------------------------------------- */
> > >  /* Type-C Partners */
> > >
> > > +/**
> > > + * typec_partner_set_usb_mode - Assign active USB Mode for the partner
> > > + * @partner: USB Type-C partner
> > > + * @mode: USB Mode (USB2, USB3 or USB4)
> > > + *
> > > + * The port drivers can use this function to assign the active USB Mode to
> > > + * @partner. The USB Mode can change for example due to Data Reset.
> > > + */
> > > +void typec_partner_set_usb_mode(struct typec_partner *partner, enum usb_mode mode)
> > > +{
> > > +   if (!partner || partner->usb_mode == mode)
> > > +           return;
> > > +
> > > +   partner->usb_capability |= BIT(mode - 1);
> > > +   partner->usb_mode = mode;
> > > +   sysfs_notify(&partner->dev.kobj, NULL, "usb_mode");
> >
> > Who is listening for this and what are they going to do with the
> > information?
>
> I'll drop it, unless Abhishek, you guys would have use for it. Let me
> know. I'll send v4 next week.

I think you are ok to remove this. We would care about this value when
registering the partner and when activating a specific USB mode. With
the latter, we can just depend on the synchronous nature of
usb_mode_store (i.e. we can check the result after writing to the
sysfs file).

>
> > > +}
> > > +EXPORT_SYMBOL_GPL(typec_partner_set_usb_mode);
> > > +
> > > +static ssize_t
> > > +usb_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
> > > +{
> > > +   struct typec_partner *partner = to_typec_partner(dev);
> > > +   int len = 0;
> > > +   int i;
> > > +
> > > +   for (i = USB_MODE_USB2; i < USB_MODE_USB4 + 1; i++) {
> > > +           if (!(BIT(i - 1) & partner->usb_capability))
> > > +                   continue;
> > > +
> > > +           if (i == partner->usb_mode)
> > > +                   len += sysfs_emit_at(buf, len, "[%s] ", usb_modes[i]);
> > > +           else
> > > +                   len += sysfs_emit_at(buf, len, "%s ", usb_modes[i]);
> > > +   }
> > > +
> > > +   buf[len - 1] = '\n';
> >
> > Again, sysfs_emit_at()?
>
> Yes. These are going back to the internal review. Too many mistakes.
> Sorry.
>
> thanks,
>
> --
> heikki
Heikki Krogerus Oct. 15, 2024, 12:13 p.m. UTC | #2 
> > > > +void typec_partner_set_usb_mode(struct typec_partner *partner, enum usb_mode mode)
> > > > +{
> > > > +   if (!partner || partner->usb_mode == mode)
> > > > +           return;
> > > > +
> > > > +   partner->usb_capability |= BIT(mode - 1);
> > > > +   partner->usb_mode = mode;
> > > > +   sysfs_notify(&partner->dev.kobj, NULL, "usb_mode");
> > >
> > > Who is listening for this and what are they going to do with the
> > > information?
> >
> > I'll drop it, unless Abhishek, you guys would have use for it. Let me
> > know. I'll send v4 next week.
> 
> I think you are ok to remove this. We would care about this value when
> registering the partner and when activating a specific USB mode. With
> the latter, we can just depend on the synchronous nature of
> usb_mode_store (i.e. we can check the result after writing to the
> sysfs file).

Okay. I'll drop it.

thanks,
diff mbox series

Patch

diff --git a/Documentation/ABI/testing/sysfs-class-typec b/Documentation/ABI/testing/sysfs-class-typec
index 7c307f02d99e..a3afe04b2688 100644
--- a/Documentation/ABI/testing/sysfs-class-typec
+++ b/Documentation/ABI/testing/sysfs-class-typec
@@ -233,6 +233,20 @@  Description:
 		directory exists, it will have an attribute file for every VDO
 		in Discover Identity command result.
 
+What:		/sys/class/typec/<port>-partner/usb_mode
+Date:		February 2024
+Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>
+Description:	The USB Modes that the partner device supports. The active mode
+		is displayed in brackets. The active USB mode can be changed by
+		writing to this file when the port driver is able to send Data
+		Reset Message to the partner. That requires USB Power Delivery
+		contract between the partner and the port.
+
+		Valid values:
+		- usb2 (USB 2.0)
+		- usb3 (USB 3.2)
+		- usb4 (USB4)
+
 USB Type-C cable devices (eg. /sys/class/typec/port0-cable/)
 
 Note: Electronically Marked Cables will have a device also for one cable plug
diff --git a/drivers/usb/typec/class.c b/drivers/usb/typec/class.c
index ea9ee47bb246..a6fedafc9c86 100644
--- a/drivers/usb/typec/class.c
+++ b/drivers/usb/typec/class.c
@@ -618,6 +618,74 @@  EXPORT_SYMBOL_GPL(typec_unregister_altmode);
 /* ------------------------------------------------------------------------- */
 /* Type-C Partners */
 
+/**
+ * typec_partner_set_usb_mode - Assign active USB Mode for the partner
+ * @partner: USB Type-C partner
+ * @mode: USB Mode (USB2, USB3 or USB4)
+ *
+ * The port drivers can use this function to assign the active USB Mode to
+ * @partner. The USB Mode can change for example due to Data Reset.
+ */
+void typec_partner_set_usb_mode(struct typec_partner *partner, enum usb_mode mode)
+{
+	if (!partner || partner->usb_mode == mode)
+		return;
+
+	partner->usb_capability |= BIT(mode - 1);
+	partner->usb_mode = mode;
+	sysfs_notify(&partner->dev.kobj, NULL, "usb_mode");
+}
+EXPORT_SYMBOL_GPL(typec_partner_set_usb_mode);
+
+static ssize_t
+usb_mode_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct typec_partner *partner = to_typec_partner(dev);
+	int len = 0;
+	int i;
+
+	for (i = USB_MODE_USB2; i < USB_MODE_USB4 + 1; i++) {
+		if (!(BIT(i - 1) & partner->usb_capability))
+			continue;
+
+		if (i == partner->usb_mode)
+			len += sysfs_emit_at(buf, len, "[%s] ", usb_modes[i]);
+		else
+			len += sysfs_emit_at(buf, len, "%s ", usb_modes[i]);
+	}
+
+	buf[len - 1] = '\n';
+	return len;
+}
+
+static ssize_t usb_mode_store(struct device *dev, struct device_attribute *attr,
+			      const char *buf, size_t size)
+{
+	struct typec_partner *partner = to_typec_partner(dev);
+	struct typec_port *port = to_typec_port(dev->parent);
+	int mode;
+	int ret;
+
+	if (!port->ops || !port->ops->enter_usb_mode)
+		return -EOPNOTSUPP;
+
+	mode = sysfs_match_string(usb_modes, buf);
+	if (mode < 0)
+		return mode;
+
+	if (mode == partner->usb_mode)
+		return size;
+
+	ret = port->ops->enter_usb_mode(port, mode);
+	if (ret)
+		return ret;
+
+	typec_partner_set_usb_mode(partner, mode);
+
+	return size;
+}
+static DEVICE_ATTR_RW(usb_mode);
+
 static ssize_t accessory_mode_show(struct device *dev,
 				   struct device_attribute *attr,
 				   char *buf)
@@ -664,6 +732,7 @@  static struct attribute *typec_partner_attrs[] = {
 	&dev_attr_supports_usb_power_delivery.attr,
 	&dev_attr_number_of_alternate_modes.attr,
 	&dev_attr_type.attr,
+	&dev_attr_usb_mode.attr,
 	&dev_attr_usb_power_delivery_revision.attr,
 	NULL
 };
@@ -671,6 +740,14 @@  static struct attribute *typec_partner_attrs[] = {
 static umode_t typec_partner_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)
 {
 	struct typec_partner *partner = to_typec_partner(kobj_to_dev(kobj));
+	struct typec_port *port = to_typec_port(partner->dev.parent);
+
+	if (attr == &dev_attr_usb_mode.attr) {
+		if (!partner->usb_capability)
+			return 0;
+		if (!port->ops || !port->ops->enter_usb_mode)
+			return 0444;
+	}
 
 	if (attr == &dev_attr_number_of_alternate_modes.attr) {
 		if (partner->num_altmodes < 0)
@@ -744,10 +821,33 @@  static void typec_partner_unlink_device(struct typec_partner *partner, struct de
  */
 int typec_partner_set_identity(struct typec_partner *partner)
 {
-	if (!partner->identity)
+	u8 usb_capability = partner->usb_capability;
+	struct device *dev = &partner->dev;
+	struct usb_pd_identity *id;
+
+	id = get_pd_identity(dev);
+	if (!id)
 		return -EINVAL;
 
-	typec_report_identity(&partner->dev);
+	if (to_typec_port(dev->parent)->data_role == TYPEC_HOST)  {
+		u32 devcap = PD_VDO_UFP_DEVCAP(id->vdo[0]);
+
+		if (devcap & (DEV_USB2_CAPABLE | DEV_USB2_BILLBOARD))
+			usb_capability |= USB_CAPABILITY_USB2;
+		if (devcap & DEV_USB3_CAPABLE)
+			usb_capability |= USB_CAPABILITY_USB3;
+		if (devcap & DEV_USB4_CAPABLE)
+			usb_capability |= USB_CAPABILITY_USB4;
+	} else {
+		usb_capability = PD_VDO_DFP_HOSTCAP(id->vdo[0]);
+	}
+
+	if (partner->usb_capability != usb_capability) {
+		partner->usb_capability = usb_capability;
+		sysfs_notify(&dev->kobj, NULL, "usb_mode");
+	}
+
+	typec_report_identity(dev);
 	return 0;
 }
 EXPORT_SYMBOL_GPL(typec_partner_set_identity);
@@ -917,6 +1017,7 @@  struct typec_partner *typec_register_partner(struct typec_port *port,
 	partner->usb_pd = desc->usb_pd;
 	partner->accessory = desc->accessory;
 	partner->num_altmodes = -1;
+	partner->usb_capability = desc->usb_capability;
 	partner->pd_revision = desc->pd_revision;
 	partner->svdm_version = port->cap->svdm_version;
 	partner->attach = desc->attach;
@@ -936,6 +1037,15 @@  struct typec_partner *typec_register_partner(struct typec_port *port,
 	partner->dev.type = &typec_partner_dev_type;
 	dev_set_name(&partner->dev, "%s-partner", dev_name(&port->dev));
 
+	if (port->usb2_dev) {
+		partner->usb_capability |= USB_CAPABILITY_USB2;
+		partner->usb_mode = USB_MODE_USB2;
+	}
+	if (port->usb3_dev) {
+		partner->usb_capability |= USB_CAPABILITY_USB2 | USB_CAPABILITY_USB3;
+		partner->usb_mode = USB_MODE_USB3;
+	}
+
 	ret = device_register(&partner->dev);
 	if (ret) {
 		dev_err(&port->dev, "failed to register partner (%d)\n", ret);
@@ -1935,13 +2045,18 @@  static void typec_partner_attach(struct typec_connector *con, struct device *dev
 	struct typec_port *port = container_of(con, struct typec_port, con);
 	struct typec_partner *partner = typec_get_partner(port);
 	struct usb_device *udev = to_usb_device(dev);
+	enum usb_mode usb_mode;
 
-	if (udev->speed < USB_SPEED_SUPER)
+	if (udev->speed < USB_SPEED_SUPER) {
+		usb_mode = USB_MODE_USB2;
 		port->usb2_dev = dev;
-	else
+	} else {
+		usb_mode = USB_MODE_USB3;
 		port->usb3_dev = dev;
+	}
 
 	if (partner) {
+		typec_partner_set_usb_mode(partner, usb_mode);
 		typec_partner_link_device(partner, dev);
 		put_device(&partner->dev);
 	}
diff --git a/drivers/usb/typec/class.h b/drivers/usb/typec/class.h
index 85bc50aa54f7..b3076a24ad2e 100644
--- a/drivers/usb/typec/class.h
+++ b/drivers/usb/typec/class.h
@@ -35,6 +35,8 @@  struct typec_partner {
 	int				num_altmodes;
 	u16				pd_revision; /* 0300H = "3.0" */
 	enum usb_pd_svdm_ver		svdm_version;
+	enum usb_mode			usb_mode;
+	u8				usb_capability;
 
 	struct usb_power_delivery	*pd;
 
diff --git a/include/linux/usb/typec.h b/include/linux/usb/typec.h
index f7edced5b10b..d616b8807000 100644
--- a/include/linux/usb/typec.h
+++ b/include/linux/usb/typec.h
@@ -220,6 +220,7 @@  struct typec_cable_desc {
  * @accessory: Audio, Debug or none.
  * @identity: Discover Identity command data
  * @pd_revision: USB Power Delivery Specification Revision if supported
+ * @usb_capability: Supported USB Modes
  * @attach: Notification about attached USB device
  * @deattach: Notification about removed USB device
  *
@@ -237,6 +238,7 @@  struct typec_partner_desc {
 	enum typec_accessory	accessory;
 	struct usb_pd_identity	*identity;
 	u16			pd_revision; /* 0300H = "3.0" */
+	u8			usb_capability;
 
 	void (*attach)(struct typec_partner *partner, struct device *dev);
 	void (*deattach)(struct typec_partner *partner, struct device *dev);
@@ -252,6 +254,7 @@  struct typec_partner_desc {
  * @pd_get: Get available USB Power Delivery Capabilities.
  * @pd_set: Set USB Power Delivery Capabilities.
  * @default_usb_mode_set: USB Mode to be used by default with Enter_USB Message
+ * @enter_usb_mode: Change the active USB Mode
  */
 struct typec_operations {
 	int (*try_role)(struct typec_port *port, int role);
@@ -263,6 +266,7 @@  struct typec_operations {
 	struct usb_power_delivery **(*pd_get)(struct typec_port *port);
 	int (*pd_set)(struct typec_port *port, struct usb_power_delivery *pd);
 	int (*default_usb_mode_set)(struct typec_port *port, enum usb_mode mode);
+	int (*enter_usb_mode)(struct typec_port *port, enum usb_mode mode);
 };
 
 enum usb_pd_svdm_ver {
@@ -365,6 +369,7 @@  int typec_port_set_usb_power_delivery(struct typec_port *port, struct usb_power_
 int typec_partner_set_usb_power_delivery(struct typec_partner *partner,
 					 struct usb_power_delivery *pd);
 
+void typec_partner_set_usb_mode(struct typec_partner *partner, enum usb_mode usb_mode);
 void typec_port_set_usb_mode(struct typec_port *port, enum usb_mode mode);
 
 /**