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usb: typec: USB Power Delivery helpers for ports and partners
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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: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Link: https://lore.kernel.org/r/20220502132058.86236-3-heikki.krogerus@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Heikki Krogerus authored and Greg Kroah-Hartman committed Jun 12, 2022
1 parent 662a601 commit a7cff92
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8 changes: 8 additions & 0 deletions Documentation/ABI/testing/sysfs-class-typec
Original file line number Diff line number Diff line change
Expand Up @@ -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
Expand Down
149 changes: 149 additions & 0 deletions drivers/usb/typec/class.c
Original file line number Diff line number Diff line change
Expand Up @@ -15,6 +15,7 @@

#include "bus.h"
#include "class.h"
#include "pd.h"

static DEFINE_IDA(typec_index_ida);

Expand Down Expand Up @@ -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.
Expand Down Expand Up @@ -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",
Expand Down Expand Up @@ -1581,6 +1713,7 @@ static const struct attribute_group typec_group = {

static const struct attribute_group *typec_groups[] = {
&typec_group,
&pd_group,
NULL
};

Expand Down Expand Up @@ -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);
Expand All @@ -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);
}
}
Expand All @@ -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);

Expand All @@ -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);
Expand Down
4 changes: 4 additions & 0 deletions drivers/usb/typec/class.h
Original file line number Diff line number Diff line change
Expand Up @@ -33,13 +33,17 @@ 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 {
unsigned int id;
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;
Expand Down
13 changes: 13 additions & 0 deletions include/linux/usb/typec.h
Original file line number Diff line number Diff line change
Expand Up @@ -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,
Expand Down Expand Up @@ -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);
Expand All @@ -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 {
Expand All @@ -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.
Expand All @@ -267,6 +274,8 @@ struct typec_capability {
struct fwnode_handle *fwnode;
void *driver_data;

struct usb_power_delivery *pd;

const struct typec_operations *ops;
};

Expand Down Expand Up @@ -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 */

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