xref: /linux-6.15/include/linux/usb/otg.h (revision bcefe12e)
1 /* USB OTG (On The Go) defines */
2 /*
3  *
4  * These APIs may be used between USB controllers.  USB device drivers
5  * (for either host or peripheral roles) don't use these calls; they
6  * continue to use just usb_device and usb_gadget.
7  */
8 
9 #ifndef __LINUX_USB_OTG_H
10 #define __LINUX_USB_OTG_H
11 
12 /* OTG defines lots of enumeration states before device reset */
13 enum usb_otg_state {
14 	OTG_STATE_UNDEFINED = 0,
15 
16 	/* single-role peripheral, and dual-role default-b */
17 	OTG_STATE_B_IDLE,
18 	OTG_STATE_B_SRP_INIT,
19 	OTG_STATE_B_PERIPHERAL,
20 
21 	/* extra dual-role default-b states */
22 	OTG_STATE_B_WAIT_ACON,
23 	OTG_STATE_B_HOST,
24 
25 	/* dual-role default-a */
26 	OTG_STATE_A_IDLE,
27 	OTG_STATE_A_WAIT_VRISE,
28 	OTG_STATE_A_WAIT_BCON,
29 	OTG_STATE_A_HOST,
30 	OTG_STATE_A_SUSPEND,
31 	OTG_STATE_A_PERIPHERAL,
32 	OTG_STATE_A_WAIT_VFALL,
33 	OTG_STATE_A_VBUS_ERR,
34 };
35 
36 /*
37  * the otg driver needs to interact with both device side and host side
38  * usb controllers.  it decides which controller is active at a given
39  * moment, using the transceiver, ID signal, HNP and sometimes static
40  * configuration information (including "board isn't wired for otg").
41  */
42 struct otg_transceiver {
43 	struct device		*dev;
44 	const char		*label;
45 
46 	u8			default_a;
47 	enum usb_otg_state	state;
48 
49 	struct usb_bus		*host;
50 	struct usb_gadget	*gadget;
51 
52 	/* to pass extra port status to the root hub */
53 	u16			port_status;
54 	u16			port_change;
55 
56 	/* bind/unbind the host controller */
57 	int	(*set_host)(struct otg_transceiver *otg,
58 				struct usb_bus *host);
59 
60 	/* bind/unbind the peripheral controller */
61 	int	(*set_peripheral)(struct otg_transceiver *otg,
62 				struct usb_gadget *gadget);
63 
64 	/* effective for B devices, ignored for A-peripheral */
65 	int	(*set_power)(struct otg_transceiver *otg,
66 				unsigned mA);
67 
68 	/* for non-OTG B devices: set transceiver into suspend mode */
69 	int	(*set_suspend)(struct otg_transceiver *otg,
70 				int suspend);
71 
72 	/* for B devices only:  start session with A-Host */
73 	int	(*start_srp)(struct otg_transceiver *otg);
74 
75 	/* start or continue HNP role switch */
76 	int	(*start_hnp)(struct otg_transceiver *otg);
77 
78 };
79 
80 
81 /* for board-specific init logic */
82 extern int otg_set_transceiver(struct otg_transceiver *);
83 
84 /* sometimes transceivers are accessed only through e.g. ULPI */
85 extern void usb_nop_xceiv_register(void);
86 extern void usb_nop_xceiv_unregister(void);
87 
88 
89 /* for usb host and peripheral controller drivers */
90 extern struct otg_transceiver *otg_get_transceiver(void);
91 extern void otg_put_transceiver(struct otg_transceiver *);
92 
93 /* Context: can sleep */
94 static inline int
95 otg_start_hnp(struct otg_transceiver *otg)
96 {
97 	return otg->start_hnp(otg);
98 }
99 
100 
101 /* for HCDs */
102 static inline int
103 otg_set_host(struct otg_transceiver *otg, struct usb_bus *host)
104 {
105 	return otg->set_host(otg, host);
106 }
107 
108 
109 /* for usb peripheral controller drivers */
110 
111 /* Context: can sleep */
112 static inline int
113 otg_set_peripheral(struct otg_transceiver *otg, struct usb_gadget *periph)
114 {
115 	return otg->set_peripheral(otg, periph);
116 }
117 
118 static inline int
119 otg_set_power(struct otg_transceiver *otg, unsigned mA)
120 {
121 	return otg->set_power(otg, mA);
122 }
123 
124 /* Context: can sleep */
125 static inline int
126 otg_set_suspend(struct otg_transceiver *otg, int suspend)
127 {
128 	if (otg->set_suspend != NULL)
129 		return otg->set_suspend(otg, suspend);
130 	else
131 		return 0;
132 }
133 
134 static inline int
135 otg_start_srp(struct otg_transceiver *otg)
136 {
137 	return otg->start_srp(otg);
138 }
139 
140 
141 /* for OTG controller drivers (and maybe other stuff) */
142 extern int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num);
143 
144 #endif /* __LINUX_USB_OTG_H */
145