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
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
76 static inline enum usb_role usb_role_switch_get_role(struct usb_role_switch *sw)
77 {
78 return USB_ROLE_NONE;
79 }
80
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 *
87 fwnode_usb_role_switch_get(struct fwnode_handle *node)
88 {
89 return ERR_PTR(-ENODEV);
90 }
91
92 static inline void usb_role_switch_put(struct usb_role_switch *sw) { }
93
94 static inline struct usb_role_switch *
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 *
101 usb_role_switch_register(struct device *parent,
102 const struct usb_role_switch_desc *desc)
103 {
104 return ERR_PTR(-ENODEV);
105 }
106
107 static inline void usb_role_switch_unregister(struct usb_role_switch *sw) { }
108
109 static inline void
110 usb_role_switch_set_drvdata(struct usb_role_switch *sw, void *data)
111 {
112 }
113
114 static inline void *usb_role_switch_get_drvdata(struct usb_role_switch *sw)
115 {
116 return NULL;
117 }
118
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
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