xref: /linux-6.15/include/linux/usb/role.h (revision c75bec79)
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  * @fwnode: The device node to be associated with the role switch
22  * @usb2_port: Optional reference to the host controller port device (USB2)
23  * @usb3_port: Optional reference to the host controller port device (USB3)
24  * @udc: Optional reference to the peripheral controller device
25  * @set: Callback for setting the role
26  * @get: Callback for getting the role (optional)
27  * @allow_userspace_control: If true userspace may change the role through sysfs
28  *
29  * @usb2_port and @usb3_port will point to the USB host port and @udc to the USB
30  * device controller behind the USB connector with the role switch. If
31  * @usb2_port, @usb3_port and @udc are included in the description, the
32  * reference count for them should be incremented by the caller of
33  * usb_role_switch_register() before registering the switch.
34  */
35 struct usb_role_switch_desc {
36 	struct fwnode_handle *fwnode;
37 	struct device *usb2_port;
38 	struct device *usb3_port;
39 	struct device *udc;
40 	usb_role_switch_set_t set;
41 	usb_role_switch_get_t get;
42 	bool allow_userspace_control;
43 };
44 
45 
46 #if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
47 int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role);
48 enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw);
49 struct usb_role_switch *usb_role_switch_get(struct device *dev);
50 struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *node);
51 void usb_role_switch_put(struct usb_role_switch *sw);
52 
53 struct usb_role_switch *
54 usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode);
55 
56 struct usb_role_switch *
57 usb_role_switch_register(struct device *parent,
58 			 const struct usb_role_switch_desc *desc);
59 void usb_role_switch_unregister(struct usb_role_switch *sw);
60 #else
61 static inline int usb_role_switch_set_role(struct usb_role_switch *sw,
62 		enum usb_role role)
63 {
64 	return 0;
65 }
66 
67 static inline enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
68 {
69 	return USB_ROLE_NONE;
70 }
71 
72 static inline struct usb_role_switch *usb_role_switch_get(struct device *dev)
73 {
74 	return ERR_PTR(-ENODEV);
75 }
76 
77 static inline struct usb_role_switch *
78 fwnode_usb_role_switch_get(struct fwnode_handle *node)
79 {
80 	return ERR_PTR(-ENODEV);
81 }
82 
83 static inline void usb_role_switch_put(struct usb_role_switch *sw) { }
84 
85 static inline struct usb_role_switch *
86 usb_role_switch_register(struct device *parent,
87 			 const struct usb_role_switch_desc *desc)
88 {
89 	return ERR_PTR(-ENODEV);
90 }
91 
92 static inline void usb_role_switch_unregister(struct usb_role_switch *sw) { }
93 #endif
94 
95 #endif /* __LINUX_USB_ROLE_H */
96