1 // SPDX-License-Identifier: GPL-2.0
3  * USB Role Switch Support
10 #include <linux/usb/role.h>
22 	enum usb_role role;  member
36  * usb_role_switch_set_role - Set USB role for a switch
37  * @sw: USB role switch
38  * @role: USB role to be switched to
40  * Set USB role @role for @sw.
42 int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)  in usb_role_switch_set_role()  argument
49 	mutex_lock(&sw->lock);  in usb_role_switch_set_role()
51 	ret = sw->set(sw, role);  in usb_role_switch_set_role()
53 		sw->role = role;  in usb_role_switch_set_role()
54 		kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);  in usb_role_switch_set_role()
57 	mutex_unlock(&sw->lock);  in usb_role_switch_set_role()
64  * usb_role_switch_get_role - Get the USB role for a switch
65  * @sw: USB role switch
67  * Depending on the role-switch-driver this function returns either a cached
68  * value of the last set role, or reads back the actual value from the hardware.
72 	enum usb_role role;  in usb_role_switch_get_role()  local
77 	mutex_lock(&sw->lock);  in usb_role_switch_get_role()
79 	if (sw->get)  in usb_role_switch_get_role()
80 		role = sw->get(sw);  in usb_role_switch_get_role()
82 		role = sw->role;  in usb_role_switch_get_role()
84 	mutex_unlock(&sw->lock);  in usb_role_switch_get_role()
86 	return role;  in usb_role_switch_get_role()
91 				   void *data)  in usb_role_switch_match()  argument
100 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_match()
109 	if (!parent || !fwnode_property_present(parent, "usb-role-switch"))  in usb_role_switch_is_parent()
113 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_is_parent()
117  * usb_role_switch_get - Find USB role switch linked with the caller
120  * Finds and returns role switch linked with @dev. The reference count for the
129 		sw = device_connection_find_match(dev, "usb-role-switch", NULL,  in usb_role_switch_get()
133 		WARN_ON(!try_module_get(sw->dev.parent->driver->owner));  in usb_role_switch_get()
140  * fwnode_usb_role_switch_get - Find USB role switch linked with the caller
152 		sw = fwnode_connection_find_match(fwnode, "usb-role-switch",  in fwnode_usb_role_switch_get()
155 		WARN_ON(!try_module_get(sw->dev.parent->driver->owner));  in fwnode_usb_role_switch_get()
162  * usb_role_switch_put - Release handle to a switch
163  * @sw: USB Role Switch
170 		module_put(sw->dev.parent->driver->owner);  in usb_role_switch_put()
171 		put_device(&sw->dev);  in usb_role_switch_put()
177  * usb_role_switch_find_by_fwnode - Find USB role switch with its fwnode
178  * @fwnode: fwnode of the USB Role Switch
180  * Finds and returns role switch with @fwnode. The reference count for the
203 	if (sw->allow_userspace_control)  in usb_role_switch_is_visible()
204 		return attr->mode;  in usb_role_switch_is_visible()
219 	enum usb_role role = usb_role_switch_get_role(sw);  in role_show()  local
221 	return sprintf(buf, "%s\n", usb_roles[role]);  in role_show()
237 			return -EINVAL;  in role_store()
246 static DEVICE_ATTR_RW(role);
290  * usb_role_switch_register - Register USB Role Switch
294  * USB Role Switch is a device capable or choosing the role for USB connector.
295  * On platforms where the USB controller is dual-role capable, the controller
300  * Returns handle to a new role switch or ERR_PTR. The content of @desc is
310 	if (!desc || !desc->set)  in usb_role_switch_register()
311 		return ERR_PTR(-EINVAL);  in usb_role_switch_register()
315 		return ERR_PTR(-ENOMEM);  in usb_role_switch_register()
317 	mutex_init(&sw->lock);  in usb_role_switch_register()
319 	sw->allow_userspace_control = desc->allow_userspace_control;  in usb_role_switch_register()
320 	sw->usb2_port = desc->usb2_port;  in usb_role_switch_register()
321 	sw->usb3_port = desc->usb3_port;  in usb_role_switch_register()
322 	sw->udc = desc->udc;  in usb_role_switch_register()
323 	sw->set = desc->set;  in usb_role_switch_register()
324 	sw->get = desc->get;  in usb_role_switch_register()
326 	sw->dev.parent = parent;  in usb_role_switch_register()
327 	sw->dev.fwnode = desc->fwnode;  in usb_role_switch_register()
328 	sw->dev.class = role_class;  in usb_role_switch_register()
329 	sw->dev.type = &usb_role_dev_type;  in usb_role_switch_register()
330 	dev_set_drvdata(&sw->dev, desc->driver_data);  in usb_role_switch_register()
331 	dev_set_name(&sw->dev, "%s-role-switch",  in usb_role_switch_register()
332 		     desc->name ? desc->name : dev_name(parent));  in usb_role_switch_register()
334 	ret = device_register(&sw->dev);  in usb_role_switch_register()
336 		put_device(&sw->dev);  in usb_role_switch_register()
347  * usb_role_switch_unregister - Unregsiter USB Role Switch
348  * @sw: USB Role Switch
355 		device_unregister(&sw->dev);  in usb_role_switch_unregister()
360  * usb_role_switch_set_drvdata - Assign private data pointer to a switch
361  * @sw: USB Role Switch
362  * @data: Private data pointer
364 void usb_role_switch_set_drvdata(struct usb_role_switch *sw, void *data)  in usb_role_switch_set_drvdata()  argument
366 	dev_set_drvdata(&sw->dev, data);  in usb_role_switch_set_drvdata()
371  * usb_role_switch_get_drvdata - Get the private data pointer of a switch
372  * @sw: USB Role Switch
376 	return dev_get_drvdata(&sw->dev);  in usb_role_switch_get_drvdata()
396 MODULE_DESCRIPTION("USB Role Class");