1 // SPDX-License-Identifier: GPL-2.0
3  * USB Role Switch Support
10 #include <linux/usb/role.h>
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.
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
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()
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
121  * found switch is incremented.
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
144  * the switch using fwnode instead of device entry.
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
181  * found switch is incremented.
193 		WARN_ON(!try_module_get(dev->parent->driver->owner));  in usb_role_switch_find_by_fwnode()
205 	if (sw->allow_userspace_control)  in usb_role_switch_is_visible()
206 		return attr->mode;  in usb_role_switch_is_visible()
245 		/* Extra check if the user wants to disable the switch */  in role_store()
248 			return -EINVAL;  in role_store()
301  * usb_role_switch_register - Register USB Role Switch
302  * @parent: Parent device for the switch
303  * @desc: Description of the switch
305  * USB Role Switch is a device capable or choosing the role for USB connector.
306  * On platforms where the USB controller is dual-role capable, the controller
307  * driver will need to register the switch. On platforms where the USB host and
308  * USB device controllers behind the connector are separate, there will be a
309  * mux, and the driver for that mux will need to register the switch.
311  * Returns handle to a new role switch or ERR_PTR. The content of @desc is
321 	if (!desc || !desc->set)  in usb_role_switch_register()
322 		return ERR_PTR(-EINVAL);  in usb_role_switch_register()
326 		return ERR_PTR(-ENOMEM);  in usb_role_switch_register()
328 	mutex_init(&sw->lock);  in usb_role_switch_register()
330 	sw->allow_userspace_control = desc->allow_userspace_control;  in usb_role_switch_register()
331 	sw->usb2_port = desc->usb2_port;  in usb_role_switch_register()
332 	sw->usb3_port = desc->usb3_port;  in usb_role_switch_register()
333 	sw->udc = desc->udc;  in usb_role_switch_register()
334 	sw->set = desc->set;  in usb_role_switch_register()
335 	sw->get = desc->get;  in usb_role_switch_register()
337 	sw->dev.parent = parent;  in usb_role_switch_register()
338 	sw->dev.fwnode = desc->fwnode;  in usb_role_switch_register()
339 	sw->dev.class = role_class;  in usb_role_switch_register()
340 	sw->dev.type = &usb_role_dev_type;  in usb_role_switch_register()
341 	dev_set_drvdata(&sw->dev, desc->driver_data);  in usb_role_switch_register()
342 	dev_set_name(&sw->dev, "%s-role-switch",  in usb_role_switch_register()
343 		     desc->name ? desc->name : dev_name(parent));  in usb_role_switch_register()
345 	ret = device_register(&sw->dev);  in usb_role_switch_register()
347 		put_device(&sw->dev);  in usb_role_switch_register()
358  * usb_role_switch_unregister - Unregsiter USB Role Switch
359  * @sw: USB Role Switch
361  * Unregister switch that was registered with usb_role_switch_register().
366 		device_unregister(&sw->dev);  in usb_role_switch_unregister()
371  * usb_role_switch_set_drvdata - Assign private data pointer to a switch
372  * @sw: USB Role Switch
377 	dev_set_drvdata(&sw->dev, data);  in usb_role_switch_set_drvdata()
382  * usb_role_switch_get_drvdata - Get the private data pointer of a switch
383  * @sw: USB Role Switch
387 	return dev_get_drvdata(&sw->dev);  in usb_role_switch_get_drvdata()
407 MODULE_DESCRIPTION("USB Role Class");