1 // SPDX-License-Identifier: GPL-2.0
2 
3 #ifndef __LINUX_USB_ROLE_H
4 #define __LINUX_USB_ROLE_H
5 
6 #include <linux/device.h>
7 
8 struct usb_role_switch;
9 
10 enum usb_role {
11 	USB_ROLE_NONE,
12 	USB_ROLE_HOST,
13 	USB_ROLE_DEVICE,
14 };
15 
16 typedef int (*usb_role_switch_set_t)(struct device *dev, enum usb_role role);
17 typedef enum usb_role (*usb_role_switch_get_t)(struct device *dev);
18 
19 /**
20  * struct usb_role_switch_desc - USB Role Switch Descriptor
21  * @usb2_port: Optional reference to the host controller port device (USB2)
22  * @usb3_port: Optional reference to the host controller port device (USB3)
23  * @udc: Optional reference to the peripheral controller device
24  * @set: Callback for setting the role
25  * @get: Callback for getting the role (optional)
26  * @allow_userspace_control: If true userspace may change the role through sysfs
27  *
28  * @usb2_port and @usb3_port will point to the USB host port and @udc to the USB
29  * device controller behind the USB connector with the role switch. If
30  * @usb2_port, @usb3_port and @udc are included in the description, the
31  * reference count for them should be incremented by the caller of
32  * usb_role_switch_register() before registering the switch.
33  */
34 struct usb_role_switch_desc {
35 	struct device *usb2_port;
36 	struct device *usb3_port;
37 	struct device *udc;
38 	usb_role_switch_set_t set;
39 	usb_role_switch_get_t get;
40 	bool allow_userspace_control;
41 };
42 
43 int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role);
44 enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw);
45 struct usb_role_switch *usb_role_switch_get(struct device *dev);
46 void usb_role_switch_put(struct usb_role_switch *sw);
47 
48 struct usb_role_switch *
49 usb_role_switch_register(struct device *parent,
50 			 const struct usb_role_switch_desc *desc);
51 void usb_role_switch_unregister(struct usb_role_switch *sw);
52 
53 #endif /* __LINUX_USB_ROLE_H */
54