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 usb_role_switch *sw,
17 				     enum usb_role role);
18 typedef enum usb_role (*usb_role_switch_get_t)(struct usb_role_switch *sw);
19 
20 /**
21  * struct usb_role_switch_desc - USB Role Switch Descriptor
22  * @fwnode: The device node to be associated with the role switch
23  * @usb2_port: Optional reference to the host controller port device (USB2)
24  * @usb3_port: Optional reference to the host controller port device (USB3)
25  * @udc: Optional reference to the peripheral controller device
26  * @set: Callback for setting the role
27  * @get: Callback for getting the role (optional)
28  * @allow_userspace_control: If true userspace may change the role through sysfs
29  * @driver_data: Private data pointer
30  * @name: Name for the switch (optional)
31  *
32  * @usb2_port and @usb3_port will point to the USB host port and @udc to the USB
33  * device controller behind the USB connector with the role switch. If
34  * @usb2_port, @usb3_port and @udc are included in the description, the
35  * reference count for them should be incremented by the caller of
36  * usb_role_switch_register() before registering the switch.
37  */
38 struct usb_role_switch_desc {
39 	struct fwnode_handle *fwnode;
40 	struct device *usb2_port;
41 	struct device *usb3_port;
42 	struct device *udc;
43 	usb_role_switch_set_t set;
44 	usb_role_switch_get_t get;
45 	bool allow_userspace_control;
46 	void *driver_data;
47 	const char *name;
48 };
49 
50 
51 #if IS_ENABLED(CONFIG_USB_ROLE_SWITCH)
52 int usb_role_switch_set_role(struct usb_role_switch *sw, enum usb_role role);
53 enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw);
54 struct usb_role_switch *usb_role_switch_get(struct device *dev);
55 struct usb_role_switch *fwnode_usb_role_switch_get(struct fwnode_handle *node);
56 void usb_role_switch_put(struct usb_role_switch *sw);
57 
58 struct usb_role_switch *
59 usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode);
60 
61 struct usb_role_switch *
62 usb_role_switch_register(struct device *parent,
63 			 const struct usb_role_switch_desc *desc);
64 void usb_role_switch_unregister(struct usb_role_switch *sw);
65 
66 void usb_role_switch_set_drvdata(struct usb_role_switch *sw, void *data);
67 void *usb_role_switch_get_drvdata(struct usb_role_switch *sw);
68 const char *usb_role_string(enum usb_role role);
69 #else
usb_role_switch_set_role(struct usb_role_switch * sw,enum usb_role role)70 static inline int usb_role_switch_set_role(struct usb_role_switch *sw,
71 		enum usb_role role)
72 {
73 	return 0;
74 }
75 
usb_role_switch_get_role(struct usb_role_switch * sw)76 static inline enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
77 {
78 	return USB_ROLE_NONE;
79 }
80 
usb_role_switch_get(struct device * dev)81 static inline struct usb_role_switch *usb_role_switch_get(struct device *dev)
82 {
83 	return ERR_PTR(-ENODEV);
84 }
85 
86 static inline struct usb_role_switch *
fwnode_usb_role_switch_get(struct fwnode_handle * node)87 fwnode_usb_role_switch_get(struct fwnode_handle *node)
88 {
89 	return ERR_PTR(-ENODEV);
90 }
91 
usb_role_switch_put(struct usb_role_switch * sw)92 static inline void usb_role_switch_put(struct usb_role_switch *sw) { }
93 
94 static inline struct usb_role_switch *
usb_role_switch_find_by_fwnode(const struct fwnode_handle * fwnode)95 usb_role_switch_find_by_fwnode(const struct fwnode_handle *fwnode)
96 {
97 	return NULL;
98 }
99 
100 static inline struct usb_role_switch *
usb_role_switch_register(struct device * parent,const struct usb_role_switch_desc * desc)101 usb_role_switch_register(struct device *parent,
102 			 const struct usb_role_switch_desc *desc)
103 {
104 	return ERR_PTR(-ENODEV);
105 }
106 
usb_role_switch_unregister(struct usb_role_switch * sw)107 static inline void usb_role_switch_unregister(struct usb_role_switch *sw) { }
108 
109 static inline void
usb_role_switch_set_drvdata(struct usb_role_switch * sw,void * data)110 usb_role_switch_set_drvdata(struct usb_role_switch *sw, void *data)
111 {
112 }
113 
usb_role_switch_get_drvdata(struct usb_role_switch * sw)114 static inline void *usb_role_switch_get_drvdata(struct usb_role_switch *sw)
115 {
116 	return NULL;
117 }
118 
usb_role_string(enum usb_role role)119 static inline const char *usb_role_string(enum usb_role role)
120 {
121 	return "unknown";
122 }
123 
124 #endif
125 
126 #endif /* __LINUX_USB_ROLE_H */
127