1 // SPDX-License-Identifier: GPL-2.0
3  * USB Role Switch Support
10 #include <linux/usb/role.h>
25 	enum usb_role role;  member
40  * usb_role_switch_set_role - Set USB role for a switch
41  * @sw: USB role switch
42  * @role: USB role to be switched to
44  * Set USB role @role for @sw.
46 int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)  in usb_role_switch_set_role()  argument
53 	if (!sw->registered)  in usb_role_switch_set_role()
54 		return -EOPNOTSUPP;  in usb_role_switch_set_role()
56 	mutex_lock(&sw->lock);  in usb_role_switch_set_role()
58 	ret = sw->set(sw, role);  in usb_role_switch_set_role()
60 		sw->role = role;  in usb_role_switch_set_role()
61 		kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);  in usb_role_switch_set_role()
64 	mutex_unlock(&sw->lock);  in usb_role_switch_set_role()
71  * usb_role_switch_get_role - Get the USB role for a switch
72  * @sw: USB role switch
74  * Depending on the role-switch-driver this function returns either a cached
75  * value of the last set role, or reads back the actual value from the hardware.
79 	enum usb_role role;  in usb_role_switch_get_role()  local
81 	if (IS_ERR_OR_NULL(sw) || !sw->registered)  in usb_role_switch_get_role()
84 	mutex_lock(&sw->lock);  in usb_role_switch_get_role()
86 	if (sw->get)  in usb_role_switch_get_role()
87 		role = sw->get(sw);  in usb_role_switch_get_role()
89 		role = sw->role;  in usb_role_switch_get_role()
91 	mutex_unlock(&sw->lock);  in usb_role_switch_get_role()
93 	return role;  in usb_role_switch_get_role()
98 				   void *data)  in usb_role_switch_match()  argument
107 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_match()
116 	if (!fwnode_property_present(parent, "usb-role-switch")) {  in usb_role_switch_is_parent()
123 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_is_parent()
127  * usb_role_switch_get - Find USB role switch linked with the caller
130  * Finds and returns role switch linked with @dev. The reference count for the
139 		sw = device_connection_find_match(dev, "usb-role-switch", NULL,  in usb_role_switch_get()
143 		WARN_ON(!try_module_get(sw->module));  in usb_role_switch_get()
150  * fwnode_usb_role_switch_get - Find USB role switch linked with the caller
162 		sw = fwnode_connection_find_match(fwnode, "usb-role-switch",  in fwnode_usb_role_switch_get()
165 		WARN_ON(!try_module_get(sw->module));  in fwnode_usb_role_switch_get()
172  * usb_role_switch_put - Release handle to a switch
173  * @sw: USB Role Switch
180 		module_put(sw->module);  in usb_role_switch_put()
181 		put_device(&sw->dev);  in usb_role_switch_put()
187  * usb_role_switch_find_by_fwnode - Find USB role switch with its fwnode
188  * @fwnode: fwnode of the USB Role Switch
190  * Finds and returns role switch with @fwnode. The reference count for the
205 		WARN_ON(!try_module_get(sw->module));  in usb_role_switch_find_by_fwnode()
218 	if (sw->allow_userspace_control)  in usb_role_switch_is_visible()
219 		return attr->mode;  in usb_role_switch_is_visible()
230 const char *usb_role_string(enum usb_role role)  in usb_role_string()  argument
232 	if (role < 0 || role >= ARRAY_SIZE(usb_roles))  in usb_role_string()
235 	return usb_roles[role];  in usb_role_string()
243 	enum usb_role role = usb_role_switch_get_role(sw);  in role_show()  local
245 	return sprintf(buf, "%s\n", usb_roles[role]);  in role_show()
261 			return -EINVAL;  in role_store()
270 static DEVICE_ATTR_RW(role);
313  * usb_role_switch_register - Register USB Role Switch
317  * USB Role Switch is a device capable or choosing the role for USB connector.
318  * On platforms where the USB controller is dual-role capable, the controller
323  * Returns handle to a new role switch or ERR_PTR. The content of @desc is
333 	if (!desc || !desc->set)  in usb_role_switch_register()
334 		return ERR_PTR(-EINVAL);  in usb_role_switch_register()
338 		return ERR_PTR(-ENOMEM);  in usb_role_switch_register()
340 	mutex_init(&sw->lock);  in usb_role_switch_register()
342 	sw->allow_userspace_control = desc->allow_userspace_control;  in usb_role_switch_register()
343 	sw->usb2_port = desc->usb2_port;  in usb_role_switch_register()
344 	sw->usb3_port = desc->usb3_port;  in usb_role_switch_register()
345 	sw->udc = desc->udc;  in usb_role_switch_register()
346 	sw->set = desc->set;  in usb_role_switch_register()
347 	sw->get = desc->get;  in usb_role_switch_register()
349 	sw->module = parent->driver->owner;  in usb_role_switch_register()
350 	sw->dev.parent = parent;  in usb_role_switch_register()
351 	sw->dev.fwnode = desc->fwnode;  in usb_role_switch_register()
352 	sw->dev.class = &role_class;  in usb_role_switch_register()
353 	sw->dev.type = &usb_role_dev_type;  in usb_role_switch_register()
354 	dev_set_drvdata(&sw->dev, desc->driver_data);  in usb_role_switch_register()
355 	dev_set_name(&sw->dev, "%s-role-switch",  in usb_role_switch_register()
356 		     desc->name ? desc->name : dev_name(parent));  in usb_role_switch_register()
358 	ret = device_register(&sw->dev);  in usb_role_switch_register()
360 		put_device(&sw->dev);  in usb_role_switch_register()
364 	sw->registered = true;  in usb_role_switch_register()
373  * usb_role_switch_unregister - Unregsiter USB Role Switch
374  * @sw: USB Role Switch
381 		sw->registered = false;  in usb_role_switch_unregister()
382 		device_unregister(&sw->dev);  in usb_role_switch_unregister()
388  * usb_role_switch_set_drvdata - Assign private data pointer to a switch
389  * @sw: USB Role Switch
390  * @data: Private data pointer
392 void usb_role_switch_set_drvdata(struct usb_role_switch *sw, void *data)  in usb_role_switch_set_drvdata()  argument
394 	dev_set_drvdata(&sw->dev, data);  in usb_role_switch_set_drvdata()
399  * usb_role_switch_get_drvdata - Get the private data pointer of a switch
400  * @sw: USB Role Switch
404 	return dev_get_drvdata(&sw->dev);  in usb_role_switch_get_drvdata()
423 MODULE_DESCRIPTION("USB Role Class");