xref: /linux-6.15/include/linux/usb/otg.h (revision 4e8cec26)
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 #include <linux/notifier.h>
13 
14 /* OTG defines lots of enumeration states before device reset */
15 enum usb_otg_state {
16 	OTG_STATE_UNDEFINED = 0,
17 
18 	/* single-role peripheral, and dual-role default-b */
19 	OTG_STATE_B_IDLE,
20 	OTG_STATE_B_SRP_INIT,
21 	OTG_STATE_B_PERIPHERAL,
22 
23 	/* extra dual-role default-b states */
24 	OTG_STATE_B_WAIT_ACON,
25 	OTG_STATE_B_HOST,
26 
27 	/* dual-role default-a */
28 	OTG_STATE_A_IDLE,
29 	OTG_STATE_A_WAIT_VRISE,
30 	OTG_STATE_A_WAIT_BCON,
31 	OTG_STATE_A_HOST,
32 	OTG_STATE_A_SUSPEND,
33 	OTG_STATE_A_PERIPHERAL,
34 	OTG_STATE_A_WAIT_VFALL,
35 	OTG_STATE_A_VBUS_ERR,
36 };
37 
38 enum usb_xceiv_events {
39 	USB_EVENT_NONE,         /* no events or cable disconnected */
40 	USB_EVENT_VBUS,         /* vbus valid event */
41 	USB_EVENT_ID,           /* id was grounded */
42 	USB_EVENT_CHARGER,      /* usb dedicated charger */
43 	USB_EVENT_ENUMERATED,   /* gadget driver enumerated */
44 };
45 
46 struct otg_transceiver;
47 
48 /* for transceivers connected thru an ULPI interface, the user must
49  * provide access ops
50  */
51 struct otg_io_access_ops {
52 	int (*read)(struct otg_transceiver *otg, u32 reg);
53 	int (*write)(struct otg_transceiver *otg, u32 val, u32 reg);
54 };
55 
56 /*
57  * the otg driver needs to interact with both device side and host side
58  * usb controllers.  it decides which controller is active at a given
59  * moment, using the transceiver, ID signal, HNP and sometimes static
60  * configuration information (including "board isn't wired for otg").
61  */
62 struct otg_transceiver {
63 	struct device		*dev;
64 	const char		*label;
65 	unsigned int		 flags;
66 
67 	u8			default_a;
68 	enum usb_otg_state	state;
69 
70 	struct usb_bus		*host;
71 	struct usb_gadget	*gadget;
72 
73 	struct otg_io_access_ops	*io_ops;
74 	void __iomem			*io_priv;
75 
76 	/* for notification of usb_xceiv_events */
77 	struct blocking_notifier_head	notifier;
78 
79 	/* to pass extra port status to the root hub */
80 	u16			port_status;
81 	u16			port_change;
82 
83 	/* initialize/shutdown the OTG controller */
84 	int	(*init)(struct otg_transceiver *otg);
85 	void	(*shutdown)(struct otg_transceiver *otg);
86 
87 	/* bind/unbind the host controller */
88 	int	(*set_host)(struct otg_transceiver *otg,
89 				struct usb_bus *host);
90 
91 	/* bind/unbind the peripheral controller */
92 	int	(*set_peripheral)(struct otg_transceiver *otg,
93 				struct usb_gadget *gadget);
94 
95 	/* effective for B devices, ignored for A-peripheral */
96 	int	(*set_power)(struct otg_transceiver *otg,
97 				unsigned mA);
98 
99 	/* effective for A-peripheral, ignored for B devices */
100 	int	(*set_vbus)(struct otg_transceiver *otg,
101 				bool enabled);
102 
103 	/* for non-OTG B devices: set transceiver into suspend mode */
104 	int	(*set_suspend)(struct otg_transceiver *otg,
105 				int suspend);
106 
107 	/* for B devices only:  start session with A-Host */
108 	int	(*start_srp)(struct otg_transceiver *otg);
109 
110 	/* start or continue HNP role switch */
111 	int	(*start_hnp)(struct otg_transceiver *otg);
112 
113 };
114 
115 
116 /* for board-specific init logic */
117 extern int otg_set_transceiver(struct otg_transceiver *);
118 
119 #if defined(CONFIG_NOP_USB_XCEIV) || defined(CONFIG_NOP_USB_XCEIV_MODULE)
120 /* sometimes transceivers are accessed only through e.g. ULPI */
121 extern void usb_nop_xceiv_register(void);
122 extern void usb_nop_xceiv_unregister(void);
123 #else
124 static inline void usb_nop_xceiv_register(void)
125 {
126 }
127 
128 static inline void usb_nop_xceiv_unregister(void)
129 {
130 }
131 #endif
132 
133 /* helpers for direct access thru low-level io interface */
134 static inline int otg_io_read(struct otg_transceiver *otg, u32 reg)
135 {
136 	if (otg->io_ops && otg->io_ops->read)
137 		return otg->io_ops->read(otg, reg);
138 
139 	return -EINVAL;
140 }
141 
142 static inline int otg_io_write(struct otg_transceiver *otg, u32 val, u32 reg)
143 {
144 	if (otg->io_ops && otg->io_ops->write)
145 		return otg->io_ops->write(otg, val, reg);
146 
147 	return -EINVAL;
148 }
149 
150 static inline int
151 otg_init(struct otg_transceiver *otg)
152 {
153 	if (otg->init)
154 		return otg->init(otg);
155 
156 	return 0;
157 }
158 
159 static inline void
160 otg_shutdown(struct otg_transceiver *otg)
161 {
162 	if (otg->shutdown)
163 		otg->shutdown(otg);
164 }
165 
166 /* for usb host and peripheral controller drivers */
167 extern struct otg_transceiver *otg_get_transceiver(void);
168 extern void otg_put_transceiver(struct otg_transceiver *);
169 
170 /* Context: can sleep */
171 static inline int
172 otg_start_hnp(struct otg_transceiver *otg)
173 {
174 	return otg->start_hnp(otg);
175 }
176 
177 /* Context: can sleep */
178 static inline int
179 otg_set_vbus(struct otg_transceiver *otg, bool enabled)
180 {
181 	return otg->set_vbus(otg, enabled);
182 }
183 
184 /* for HCDs */
185 static inline int
186 otg_set_host(struct otg_transceiver *otg, struct usb_bus *host)
187 {
188 	return otg->set_host(otg, host);
189 }
190 
191 /* for usb peripheral controller drivers */
192 
193 /* Context: can sleep */
194 static inline int
195 otg_set_peripheral(struct otg_transceiver *otg, struct usb_gadget *periph)
196 {
197 	return otg->set_peripheral(otg, periph);
198 }
199 
200 static inline int
201 otg_set_power(struct otg_transceiver *otg, unsigned mA)
202 {
203 	return otg->set_power(otg, mA);
204 }
205 
206 /* Context: can sleep */
207 static inline int
208 otg_set_suspend(struct otg_transceiver *otg, int suspend)
209 {
210 	if (otg->set_suspend != NULL)
211 		return otg->set_suspend(otg, suspend);
212 	else
213 		return 0;
214 }
215 
216 static inline int
217 otg_start_srp(struct otg_transceiver *otg)
218 {
219 	return otg->start_srp(otg);
220 }
221 
222 /* notifiers */
223 static inline int
224 otg_register_notifier(struct otg_transceiver *otg, struct notifier_block *nb)
225 {
226 	return blocking_notifier_chain_register(&otg->notifier, nb);
227 }
228 
229 static inline void
230 otg_unregister_notifier(struct otg_transceiver *otg, struct notifier_block *nb)
231 {
232 	blocking_notifier_chain_unregister(&otg->notifier, nb);
233 }
234 
235 /* for OTG controller drivers (and maybe other stuff) */
236 extern int usb_bus_start_enum(struct usb_bus *bus, unsigned port_num);
237 
238 #endif /* __LINUX_USB_OTG_H */
239