1 // SPDX-License-Identifier: GPL-2.0
3  * USB Role Switch Support
11 #include <linux/usb/role.h>
28 	enum usb_role role;  member
46 	ret = sysfs_create_link(&dev->kobj, &connector->kobj, "connector");  in connector_bind()
50 	ret = sysfs_create_link(&connector->kobj, &dev->kobj, "usb-role-switch");  in connector_bind()
52 		sysfs_remove_link(&dev->kobj, "connector");  in connector_bind()
59 	sysfs_remove_link(&connector->kobj, "usb-role-switch");  in connector_unbind()
60 	sysfs_remove_link(&dev->kobj, "connector");  in connector_unbind()
69  * usb_role_switch_set_role - Set USB role for a switch
70  * @sw: USB role switch
71  * @role: USB role to be switched to
73  * Set USB role @role for @sw.
75 int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role)  in usb_role_switch_set_role()  argument
82 	if (!sw->registered)  in usb_role_switch_set_role()
83 		return -EOPNOTSUPP;  in usb_role_switch_set_role()
85 	mutex_lock(&sw->lock);  in usb_role_switch_set_role()
87 	ret = sw->set(sw, role);  in usb_role_switch_set_role()
89 		sw->role = role;  in usb_role_switch_set_role()
90 		kobject_uevent(&sw->dev.kobj, KOBJ_CHANGE);  in usb_role_switch_set_role()
93 	mutex_unlock(&sw->lock);  in usb_role_switch_set_role()
100  * usb_role_switch_get_role - Get the USB role for a switch
101  * @sw: USB role switch
103  * Depending on the role-switch-driver this function returns either a cached
104  * value of the last set role, or reads back the actual value from the hardware.
108 	enum usb_role role;  in usb_role_switch_get_role()  local
110 	if (IS_ERR_OR_NULL(sw) || !sw->registered)  in usb_role_switch_get_role()
113 	mutex_lock(&sw->lock);  in usb_role_switch_get_role()
115 	if (sw->get)  in usb_role_switch_get_role()
116 		role = sw->get(sw);  in usb_role_switch_get_role()
118 		role = sw->role;  in usb_role_switch_get_role()
120 	mutex_unlock(&sw->lock);  in usb_role_switch_get_role()
122 	return role;  in usb_role_switch_get_role()
136 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_match()
145 	if (!fwnode_property_present(parent, "usb-role-switch")) {  in usb_role_switch_is_parent()
152 	return dev ? to_role_switch(dev) : ERR_PTR(-EPROBE_DEFER);  in usb_role_switch_is_parent()
156  * usb_role_switch_get - Find USB role switch linked with the caller
159  * Finds and returns role switch linked with @dev. The reference count for the
160  * found switch is incremented.
168 		sw = device_connection_find_match(dev, "usb-role-switch", NULL,  in usb_role_switch_get()
172 		WARN_ON(!try_module_get(sw->module));  in usb_role_switch_get()
179  * fwnode_usb_role_switch_get - Find USB role switch linked with the caller
183  * the switch using fwnode instead of device entry.
191 		sw = fwnode_connection_find_match(fwnode, "usb-role-switch",  in fwnode_usb_role_switch_get()
194 		WARN_ON(!try_module_get(sw->module));  in fwnode_usb_role_switch_get()
201  * usb_role_switch_put - Release handle to a switch
202  * @sw: USB Role Switch
209 		module_put(sw->module);  in usb_role_switch_put()
210 		put_device(&sw->dev);  in usb_role_switch_put()
216  * usb_role_switch_find_by_fwnode - Find USB role switch with its fwnode
217  * @fwnode: fwnode of the USB Role Switch
219  * Finds and returns role switch with @fwnode. The reference count for the
220  * found switch is incremented.
234 		WARN_ON(!try_module_get(sw->module));  in usb_role_switch_find_by_fwnode()
247 	if (sw->allow_userspace_control)  in usb_role_switch_is_visible()
248 		return attr->mode;  in usb_role_switch_is_visible()
259 const char *usb_role_string(enum usb_role role)  in usb_role_string()  argument
261 	if (role < 0 || role >= ARRAY_SIZE(usb_roles))  in usb_role_string()
264 	return usb_roles[role];  in usb_role_string()
272 	enum usb_role role = usb_role_switch_get_role(sw);  in role_show()  local
274 	return sprintf(buf, "%s\n", usb_roles[role]);  in role_show()
287 		/* Extra check if the user wants to disable the switch */  in role_store()
290 			return -EINVAL;  in role_store()
299 static DEVICE_ATTR_RW(role);
331 	mutex_destroy(&sw->lock);  in usb_role_switch_release()
332 	lockdep_unregister_key(&sw->key);  in usb_role_switch_release()
344  * usb_role_switch_register - Register USB Role Switch
345  * @parent: Parent device for the switch
346  * @desc: Description of the switch
348  * USB Role Switch is a device capable or choosing the role for USB connector.
349  * On platforms where the USB controller is dual-role capable, the controller
350  * driver will need to register the switch. On platforms where the USB host and
351  * USB device controllers behind the connector are separate, there will be a
352  * mux, and the driver for that mux will need to register the switch.
354  * Returns handle to a new role switch or ERR_PTR. The content of @desc is
364 	if (!desc || !desc->set)  in usb_role_switch_register()
365 		return ERR_PTR(-EINVAL);  in usb_role_switch_register()
369 		return ERR_PTR(-ENOMEM);  in usb_role_switch_register()
371 	lockdep_register_key(&sw->key);  in usb_role_switch_register()
372 	mutex_init_with_key(&sw->lock, &sw->key);  in usb_role_switch_register()
374 	sw->allow_userspace_control = desc->allow_userspace_control;  in usb_role_switch_register()
375 	sw->usb2_port = desc->usb2_port;  in usb_role_switch_register()
376 	sw->usb3_port = desc->usb3_port;  in usb_role_switch_register()
377 	sw->udc = desc->udc;  in usb_role_switch_register()
378 	sw->set = desc->set;  in usb_role_switch_register()
379 	sw->get = desc->get;  in usb_role_switch_register()
381 	sw->module = parent->driver->owner;  in usb_role_switch_register()
382 	sw->dev.parent = parent;  in usb_role_switch_register()
383 	sw->dev.fwnode = desc->fwnode;  in usb_role_switch_register()
384 	sw->dev.class = &role_class;  in usb_role_switch_register()
385 	sw->dev.type = &usb_role_dev_type;  in usb_role_switch_register()
386 	dev_set_drvdata(&sw->dev, desc->driver_data);  in usb_role_switch_register()
387 	dev_set_name(&sw->dev, "%s-role-switch",  in usb_role_switch_register()
388 		     desc->name ? desc->name : dev_name(parent));  in usb_role_switch_register()
390 	sw->registered = true;  in usb_role_switch_register()
392 	ret = device_register(&sw->dev);  in usb_role_switch_register()
394 		sw->registered = false;  in usb_role_switch_register()
395 		put_device(&sw->dev);  in usb_role_switch_register()
399 	if (dev_fwnode(&sw->dev)) {  in usb_role_switch_register()
400 		ret = component_add(&sw->dev, &connector_ops);  in usb_role_switch_register()
402 			dev_warn(&sw->dev, "failed to add component\n");  in usb_role_switch_register()
412  * usb_role_switch_unregister - Unregsiter USB Role Switch
413  * @sw: USB Role Switch
415  * Unregister switch that was registered with usb_role_switch_register().
421 	sw->registered = false;  in usb_role_switch_unregister()
422 	if (dev_fwnode(&sw->dev))  in usb_role_switch_unregister()
423 		component_del(&sw->dev, &connector_ops);  in usb_role_switch_unregister()
424 	device_unregister(&sw->dev);  in usb_role_switch_unregister()
429  * usb_role_switch_set_drvdata - Assign private data pointer to a switch
430  * @sw: USB Role Switch
435 	dev_set_drvdata(&sw->dev, data);  in usb_role_switch_set_drvdata()
440  * usb_role_switch_get_drvdata - Get the private data pointer of a switch
441  * @sw: USB Role Switch
445 	return dev_get_drvdata(&sw->dev);  in usb_role_switch_get_drvdata()
464 MODULE_DESCRIPTION("USB Role Class");