1 // SPDX-License-Identifier: GPL-2.0
3  * USB Role Switch Support
10 #include <linux/usb/role.h>
37  * usb_role_switch_set_role - Set USB role for a switch
38  * @sw: USB role switch
39  * @role: USB role to be switched to
41  * Set USB role @role for @sw.
50 	mutex_lock(&sw->lock);  in usb_role_switch_set_role()
52 	ret = sw->set(sw, role);  in usb_role_switch_set_role()
54 		sw->role = role;  in usb_role_switch_set_role()
55 		kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);  in usb_role_switch_set_role()
58 	mutex_unlock(&sw->lock);  in usb_role_switch_set_role()
65  * usb_role_switch_get_role - Get the USB role for a switch
66  * @sw: USB role switch
68  * Depending on the role-switch-driver this function returns either a cached
78 	mutex_lock(&sw->lock);  in usb_role_switch_get_role()
80 	if (sw->get)  in usb_role_switch_get_role()
81 		role = sw->get(sw);  in usb_role_switch_get_role()
83 		role = sw->role;  in usb_role_switch_get_role()
85 	mutex_unlock(&sw->lock);  in usb_role_switch_get_role()
101 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_match()
110 	if (!fwnode_property_present(parent, "usb-role-switch")) {  in usb_role_switch_is_parent()
117 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_is_parent()
121  * usb_role_switch_get - Find USB role switch linked with the caller
124  * Finds and returns role switch linked with @dev. The reference count for the
125  * found switch is incremented.
133 		sw = device_connection_find_match(dev, "usb-role-switch", NULL,  in usb_role_switch_get()
137 		WARN_ON(!try_module_get(sw->module));  in usb_role_switch_get()
144  * fwnode_usb_role_switch_get - Find USB role switch linked with the caller
148  * the switch using fwnode instead of device entry.
156 		sw = fwnode_connection_find_match(fwnode, "usb-role-switch",  in fwnode_usb_role_switch_get()
159 		WARN_ON(!try_module_get(sw->module));  in fwnode_usb_role_switch_get()
166  * usb_role_switch_put - Release handle to a switch
167  * @sw: USB Role Switch
174 		module_put(sw->module);  in usb_role_switch_put()
175 		put_device(&sw->dev);  in usb_role_switch_put()
181  * usb_role_switch_find_by_fwnode - Find USB role switch with its fwnode
182  * @fwnode: fwnode of the USB Role Switch
184  * Finds and returns role switch with @fwnode. The reference count for the
185  * found switch is incremented.
199 		WARN_ON(!try_module_get(sw->module));  in usb_role_switch_find_by_fwnode()
212 	if (sw->allow_userspace_control)  in usb_role_switch_is_visible()
213 		return attr->mode;  in usb_role_switch_is_visible()
243 		/* Extra check if the user wants to disable the switch */  in role_store()
246 			return -EINVAL;  in role_store()
299  * usb_role_switch_register - Register USB Role Switch
300  * @parent: Parent device for the switch
301  * @desc: Description of the switch
303  * USB Role Switch is a device capable or choosing the role for USB connector.
304  * On platforms where the USB controller is dual-role capable, the controller
305  * driver will need to register the switch. On platforms where the USB host and
306  * USB device controllers behind the connector are separate, there will be a
307  * mux, and the driver for that mux will need to register the switch.
309  * Returns handle to a new role switch or ERR_PTR. The content of @desc is
319 	if (!desc || !desc->set)  in usb_role_switch_register()
320 		return ERR_PTR(-EINVAL);  in usb_role_switch_register()
324 		return ERR_PTR(-ENOMEM);  in usb_role_switch_register()
326 	mutex_init(&sw->lock);  in usb_role_switch_register()
328 	sw->allow_userspace_control = desc->allow_userspace_control;  in usb_role_switch_register()
329 	sw->usb2_port = desc->usb2_port;  in usb_role_switch_register()
330 	sw->usb3_port = desc->usb3_port;  in usb_role_switch_register()
331 	sw->udc = desc->udc;  in usb_role_switch_register()
332 	sw->set = desc->set;  in usb_role_switch_register()
333 	sw->get = desc->get;  in usb_role_switch_register()
335 	sw->module = parent->driver->owner;  in usb_role_switch_register()
336 	sw->dev.parent = parent;  in usb_role_switch_register()
337 	sw->dev.fwnode = desc->fwnode;  in usb_role_switch_register()
338 	sw->dev.class = role_class;  in usb_role_switch_register()
339 	sw->dev.type = &usb_role_dev_type;  in usb_role_switch_register()
340 	dev_set_drvdata(&sw->dev, desc->driver_data);  in usb_role_switch_register()
341 	dev_set_name(&sw->dev, "%s-role-switch",  in usb_role_switch_register()
342 		     desc->name ? desc->name : dev_name(parent));  in usb_role_switch_register()
344 	ret = device_register(&sw->dev);  in usb_role_switch_register()
346 		put_device(&sw->dev);  in usb_role_switch_register()
357  * usb_role_switch_unregister - Unregsiter USB Role Switch
358  * @sw: USB Role Switch
360  * Unregister switch that was registered with usb_role_switch_register().
365 		device_unregister(&sw->dev);  in usb_role_switch_unregister()
370  * usb_role_switch_set_drvdata - Assign private data pointer to a switch
371  * @sw: USB Role Switch
376 	dev_set_drvdata(&sw->dev, data);  in usb_role_switch_set_drvdata()
381  * usb_role_switch_get_drvdata - Get the private data pointer of a switch
382  * @sw: USB Role Switch
386 	return dev_get_drvdata(&sw->dev);  in usb_role_switch_get_drvdata()
406 MODULE_DESCRIPTION("USB Role Class");