xref: /linux-6.15/include/linux/usb/otg.h (revision 643d1f7f)
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 
10 /* OTG defines lots of enumeration states before device reset */
11 enum usb_otg_state {
12 	OTG_STATE_UNDEFINED = 0,
13 
14 	/* single-role peripheral, and dual-role default-b */
15 	OTG_STATE_B_IDLE,
16 	OTG_STATE_B_SRP_INIT,
17 	OTG_STATE_B_PERIPHERAL,
18 
19 	/* extra dual-role default-b states */
20 	OTG_STATE_B_WAIT_ACON,
21 	OTG_STATE_B_HOST,
22 
23 	/* dual-role default-a */
24 	OTG_STATE_A_IDLE,
25 	OTG_STATE_A_WAIT_VRISE,
26 	OTG_STATE_A_WAIT_BCON,
27 	OTG_STATE_A_HOST,
28 	OTG_STATE_A_SUSPEND,
29 	OTG_STATE_A_PERIPHERAL,
30 	OTG_STATE_A_WAIT_VFALL,
31 	OTG_STATE_A_VBUS_ERR,
32 };
33 
34 /*
35  * the otg driver needs to interact with both device side and host side
36  * usb controllers.  it decides which controller is active at a given
37  * moment, using the transceiver, ID signal, HNP and sometimes static
38  * configuration information (including "board isn't wired for otg").
39  */
40 struct otg_transceiver {
41 	struct device		*dev;
42 	const char		*label;
43 
44 	u8			default_a;
45 	enum usb_otg_state	state;
46 
47 	struct usb_bus		*host;
48 	struct usb_gadget	*gadget;
49 
50 	/* to pass extra port status to the root hub */
51 	u16			port_status;
52 	u16			port_change;
53 
54 	/* bind/unbind the host controller */
55 	int	(*set_host)(struct otg_transceiver *otg,
56 				struct usb_bus *host);
57 
58 	/* bind/unbind the peripheral controller */
59 	int	(*set_peripheral)(struct otg_transceiver *otg,
60 				struct usb_gadget *gadget);
61 
62 	/* effective for B devices, ignored for A-peripheral */
63 	int	(*set_power)(struct otg_transceiver *otg,
64 				unsigned mA);
65 
66 	/* for non-OTG B devices: set transceiver into suspend mode */
67 	int	(*set_suspend)(struct otg_transceiver *otg,
68 				int suspend);
69 
70 	/* for B devices only:  start session with A-Host */
71 	int	(*start_srp)(struct otg_transceiver *otg);
72 
73 	/* start or continue HNP role switch */
74 	int	(*start_hnp)(struct otg_transceiver *otg);
75 
76 };
77 
78 
79 /* for board-specific init logic */
80 extern int otg_set_transceiver(struct otg_transceiver *);
81 
82 
83 /* for usb host and peripheral controller drivers */
84 extern struct otg_transceiver *otg_get_transceiver(void);
85 
86 static inline int
87 otg_start_hnp(struct otg_transceiver *otg)
88 {
89 	return otg->start_hnp(otg);
90 }
91 
92 
93 /* for HCDs */
94 static inline int
95 otg_set_host(struct otg_transceiver *otg, struct usb_bus *host)
96 {
97 	return otg->set_host(otg, host);
98 }
99 
100 
101 /* for usb peripheral controller drivers */
102 static inline int
103 otg_set_peripheral(struct otg_transceiver *otg, struct usb_gadget *periph)
104 {
105 	return otg->set_peripheral(otg, periph);
106 }
107 
108 static inline int
109 otg_set_power(struct otg_transceiver *otg, unsigned mA)
110 {
111 	return otg->set_power(otg, mA);
112 }
113 
114 static inline int
115 otg_set_suspend(struct otg_transceiver *otg, int suspend)
116 {
117 	if (otg->set_suspend != NULL)
118 		return otg->set_suspend(otg, suspend);
119 	else
120 		return 0;
121 }
122 
123 static inline int
124 otg_start_srp(struct otg_transceiver *otg)
125 {
126 	return otg->start_srp(otg);
127 }
128 
129 
130 /* for OTG controller drivers (and maybe other stuff) */
131 extern int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num);
132