Commit a7cff92f authored by Heikki Krogerus's avatar Heikki Krogerus Committed by Greg Kroah-Hartman
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usb: typec: USB Power Delivery helpers for ports and partners 



All the USB Type-C Connector Class devices are protected, so
the drivers can not directly access them. This will adds a
few helpers that can be used to link the ports and partners
to the correct USB Power Delivery objects.

For ports a new optional sysfs attribute file is also added
that can be used to select the USB Power Delivery
capabilities that the port will advertise to the partner.

Signed-off-by: default avatarHeikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20220502132058.86236-3-heikki.krogerus@linux.intel.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 662a6010

Documentation/ABI/testing/sysfs-class-typec

+8 −0
Original line number Diff line number Diff line
@@ -141,6 +141,14 @@ Description: 
		- "reverse": CC2 orientation

		- "unknown": Orientation cannot be determined.



What:		/sys/class/typec/<port>/select_usb_power_delivery

Date:		May 2022

Contact:	Heikki Krogerus <heikki.krogerus@linux.intel.com>

Description:

		Lists the USB Power Delivery Capabilities that the port can

		advertise to the partner. The currently used capabilities are in

		brackets. Selection happens by writing to the file.



USB Type-C partner devices (eg. /sys/class/typec/port0-partner/)



What:		/sys/class/typec/<port>-partner/accessory_mode

drivers/usb/typec/class.c

+149 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 


#include "bus.h"

#include "class.h"

#include "pd.h"



static DEFINE_IDA(typec_index_ida);
@@ -720,6 +721,39 @@ void typec_partner_set_pd_revision(struct typec_partner *partner, u16 pd_revisio 
}

EXPORT_SYMBOL_GPL(typec_partner_set_pd_revision);



/**

 * typec_partner_set_usb_power_delivery - Declare USB Power Delivery Contract.

 * @partner: The partner device.

 * @pd: The USB PD instance.

 *

 * This routine can be used to declare USB Power Delivery Contract with @partner

 * by linking @partner to @pd which contains the objects that were used during the

 * negotiation of the contract.

 *

 * If @pd is NULL, the link is removed and the contract with @partner has ended.

 */

int typec_partner_set_usb_power_delivery(struct typec_partner *partner,

					 struct usb_power_delivery *pd)

{

	int ret;



	if (IS_ERR_OR_NULL(partner) || partner->pd == pd)

		return 0;



	if (pd) {

		ret = usb_power_delivery_link_device(pd, &partner->dev);

		if (ret)

			return ret;

	} else {

		usb_power_delivery_unlink_device(partner->pd, &partner->dev);

	}



	partner->pd = pd;



	return 0;

}

EXPORT_SYMBOL_GPL(typec_partner_set_usb_power_delivery);



/**

 * typec_partner_set_num_altmodes - Set the number of available partner altmodes

 * @partner: The partner to be updated.
@@ -1170,6 +1204,104 @@ EXPORT_SYMBOL_GPL(typec_unregister_cable); 
/* ------------------------------------------------------------------------- */

/* USB Type-C ports */



/**

 * typec_port_set_usb_power_delivery - Assign USB PD for port.

 * @port: USB Type-C port.

 * @pd: USB PD instance.

 *

 * This routine can be used to set the USB Power Delivery Capabilities for @port

 * that it will advertise to the partner.

 *

 * If @pd is NULL, the assignment is removed.

 */

int typec_port_set_usb_power_delivery(struct typec_port *port, struct usb_power_delivery *pd)

{

	int ret;



	if (IS_ERR_OR_NULL(port) || port->pd == pd)

		return 0;



	if (pd) {

		ret = usb_power_delivery_link_device(pd, &port->dev);

		if (ret)

			return ret;

	} else {

		usb_power_delivery_unlink_device(port->pd, &port->dev);

	}



	port->pd = pd;



	return 0;

}

EXPORT_SYMBOL_GPL(typec_port_set_usb_power_delivery);



static ssize_t select_usb_power_delivery_store(struct device *dev,

					       struct device_attribute *attr,

					       const char *buf, size_t size)

{

	struct typec_port *port = to_typec_port(dev);

	struct usb_power_delivery *pd;



	if (!port->ops || !port->ops->pd_set)

		return -EOPNOTSUPP;



	pd = usb_power_delivery_find(buf);

	if (!pd)

		return -EINVAL;



	return port->ops->pd_set(port, pd);

}



static ssize_t select_usb_power_delivery_show(struct device *dev,

					      struct device_attribute *attr, char *buf)

{

	struct typec_port *port = to_typec_port(dev);

	struct usb_power_delivery **pds;

	struct usb_power_delivery *pd;

	int ret = 0;



	if (!port->ops || !port->ops->pd_get)

		return -EOPNOTSUPP;



	pds = port->ops->pd_get(port);

	if (!pds)

		return 0;



	for (pd = pds[0]; pd; pd++) {

		if (pd == port->pd)

			ret += sysfs_emit(buf + ret, "[%s] ", dev_name(&pd->dev));

		else

			ret += sysfs_emit(buf + ret, "%s ", dev_name(&pd->dev));

	}



	buf[ret - 1] = '\n';



	return ret;

}

static DEVICE_ATTR_RW(select_usb_power_delivery);



static struct attribute *port_attrs[] = {

	&dev_attr_select_usb_power_delivery.attr,

	NULL

};



static umode_t port_attr_is_visible(struct kobject *kobj, struct attribute *attr, int n)

{

	struct typec_port *port = to_typec_port(kobj_to_dev(kobj));



	if (!port->pd || !port->ops || !port->ops->pd_get)

		return 0;

	if (!port->ops->pd_set)

		return 0444;



	return attr->mode;

}



static const struct attribute_group pd_group = {

	.is_visible = port_attr_is_visible,

	.attrs = port_attrs,

};



static const char * const typec_orientations[] = {

	[TYPEC_ORIENTATION_NONE]	= "unknown",

	[TYPEC_ORIENTATION_NORMAL]	= "normal",
@@ -1581,6 +1713,7 @@ static const struct attribute_group typec_group = { 


static const struct attribute_group *typec_groups[] = {

	&typec_group,

	&pd_group,

	NULL

};
@@ -2123,6 +2256,13 @@ struct typec_port *typec_register_port(struct device *parent, 
		return ERR_PTR(ret);

	}



	ret = typec_port_set_usb_power_delivery(port, cap->pd);

	if (ret) {

		dev_err(&port->dev, "failed to link pd\n");

		device_unregister(&port->dev);

		return ERR_PTR(ret);

	}



	ret = typec_link_ports(port);

	if (ret)

		dev_warn(&port->dev, "failed to create symlinks (%d)\n", ret);
@@ -2141,6 +2281,7 @@ void typec_unregister_port(struct typec_port *port) 
{

	if (!IS_ERR_OR_NULL(port)) {

		typec_unlink_ports(port);

		typec_port_set_usb_power_delivery(port, NULL);

		device_unregister(&port->dev);

	}

}
@@ -2162,8 +2303,15 @@ static int __init typec_init(void) 
	if (ret)

		goto err_unregister_mux_class;



	ret = usb_power_delivery_init();

	if (ret)

		goto err_unregister_class;



	return 0;



err_unregister_class:

	class_unregister(&typec_class);



err_unregister_mux_class:

	class_unregister(&typec_mux_class);
@@ -2176,6 +2324,7 @@ subsys_initcall(typec_init); 


static void __exit typec_exit(void)

{

	usb_power_delivery_exit();

	class_unregister(&typec_class);

	ida_destroy(&typec_index_ida);

	bus_unregister(&typec_bus);

drivers/usb/typec/class.h

+4 −0
Original line number Diff line number Diff line
@@ -33,6 +33,8 @@ struct typec_partner { 
	int				num_altmodes;

	u16				pd_revision; /* 0300H = "3.0" */

	enum usb_pd_svdm_ver		svdm_version;



	struct usb_power_delivery	*pd;

};



struct typec_port {
@@ -40,6 +42,8 @@ struct typec_port { 
	struct device			dev;

	struct ida			mode_ids;



	struct usb_power_delivery	*pd;



	int				prefer_role;

	enum typec_data_role		data_role;

	enum typec_role			pwr_role;

include/linux/usb/typec.h

+13 −0
Original line number Diff line number Diff line
@@ -22,6 +22,8 @@ struct typec_altmode_ops; 
struct fwnode_handle;

struct device;



struct usb_power_delivery;



enum typec_port_type {

	TYPEC_PORT_SRC,

	TYPEC_PORT_SNK,
@@ -223,6 +225,8 @@ struct typec_partner_desc { 
 * @pr_set: Set Power Role

 * @vconn_set: Source VCONN

 * @port_type_set: Set port type

 * @pd_get: Get available USB Power Delivery Capabilities.

 * @pd_set: Set USB Power Delivery Capabilities.

 */

struct typec_operations {

	int (*try_role)(struct typec_port *port, int role);
@@ -231,6 +235,8 @@ struct typec_operations { 
	int (*vconn_set)(struct typec_port *port, enum typec_role role);

	int (*port_type_set)(struct typec_port *port,

			     enum typec_port_type type);

	struct usb_power_delivery **(*pd_get)(struct typec_port *port);

	int (*pd_set)(struct typec_port *port, struct usb_power_delivery *pd);

};



enum usb_pd_svdm_ver {
@@ -250,6 +256,7 @@ enum usb_pd_svdm_ver { 
 * @accessory: Supported Accessory Modes

 * @fwnode: Optional fwnode of the port

 * @driver_data: Private pointer for driver specific info

 * @pd: Optional USB Power Delivery Support

 * @ops: Port operations vector

 *

 * Static capabilities of a single USB Type-C port.
@@ -267,6 +274,8 @@ struct typec_capability { 
	struct fwnode_handle	*fwnode;

	void			*driver_data;



	struct usb_power_delivery *pd;



	const struct typec_operations	*ops;

};
@@ -318,4 +327,8 @@ void typec_partner_set_svdm_version(struct typec_partner *partner, 
				    enum usb_pd_svdm_ver svdm_version);

int typec_get_negotiated_svdm_version(struct typec_port *port);



int typec_port_set_usb_power_delivery(struct typec_port *port, struct usb_power_delivery *pd);

int typec_partner_set_usb_power_delivery(struct typec_partner *partner,

					 struct usb_power_delivery *pd);



#endif /* __LINUX_USB_TYPEC_H */