1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
4  */
5 
6 #ifndef __LINUX_USB_OTG_FSM_H
7 #define __LINUX_USB_OTG_FSM_H
8 
9 #include <linux/mutex.h>
10 #include <linux/errno.h>
11 
12 #define PROTO_UNDEF	(0)
13 #define PROTO_HOST	(1)
14 #define PROTO_GADGET	(2)
15 
16 #define OTG_STS_SELECTOR	0xF000	/* OTG status selector, according to
17 					 * OTG and EH 2.0 Chapter 6.2.3
18 					 * Table:6-4
19 					 */
20 
21 #define HOST_REQUEST_FLAG	1	/* Host request flag, according to
22 					 * OTG and EH 2.0 Charpter 6.2.3
23 					 * Table:6-5
24 					 */
25 
26 #define T_HOST_REQ_POLL		(1500)	/* 1500ms, HNP polling interval */
27 
28 enum otg_fsm_timer {
29 	/* Standard OTG timers */
30 	A_WAIT_VRISE,
31 	A_WAIT_VFALL,
32 	A_WAIT_BCON,
33 	A_AIDL_BDIS,
34 	B_ASE0_BRST,
35 	A_BIDL_ADIS,
36 	B_AIDL_BDIS,
37 
38 	/* Auxiliary timers */
39 	B_SE0_SRP,
40 	B_SRP_FAIL,
41 	A_WAIT_ENUM,
42 	B_DATA_PLS,
43 	B_SSEND_SRP,
44 
45 	NUM_OTG_FSM_TIMERS,
46 };
47 
48 /**
49  * struct otg_fsm - OTG state machine according to the OTG spec
50  *
51  * OTG hardware Inputs
52  *
53  *	Common inputs for A and B device
54  * @id:		TRUE for B-device, FALSE for A-device.
55  * @adp_change: TRUE when current ADP measurement (n) value, compared to the
56  *		ADP measurement taken at n-2, differs by more than CADP_THR
57  * @power_up:	TRUE when the OTG device first powers up its USB system and
58  *		ADP measurement taken if ADP capable
59  *
60  *	A-Device state inputs
61  * @a_srp_det:	TRUE if the A-device detects SRP
62  * @a_vbus_vld:	TRUE when VBUS voltage is in regulation
63  * @b_conn:	TRUE if the A-device detects connection from the B-device
64  * @a_bus_resume: TRUE when the B-device detects that the A-device is signaling
65  *		  a resume (K state)
66  *	B-Device state inputs
67  * @a_bus_suspend: TRUE when the B-device detects that the A-device has put the
68  *		bus into suspend
69  * @a_conn:	TRUE if the B-device detects a connection from the A-device
70  * @b_se0_srp:	TRUE when the line has been at SE0 for more than the minimum
71  *		time before generating SRP
72  * @b_ssend_srp: TRUE when the VBUS has been below VOTG_SESS_VLD for more than
73  *		 the minimum time before generating SRP
74  * @b_sess_vld:	TRUE when the B-device detects that the voltage on VBUS is
75  *		above VOTG_SESS_VLD
76  * @test_device: TRUE when the B-device switches to B-Host and detects an OTG
77  *		test device. This must be set by host/hub driver
78  *
79  *	Application inputs (A-Device)
80  * @a_bus_drop:	TRUE when A-device application needs to power down the bus
81  * @a_bus_req:	TRUE when A-device application wants to use the bus.
82  *		FALSE to suspend the bus
83  *
84  *	Application inputs (B-Device)
85  * @b_bus_req:	TRUE during the time that the Application running on the
86  *		B-device wants to use the bus
87  *
88  *	Auxiliary inputs (OTG v1.3 only. Obsolete now.)
89  * @a_sess_vld:	TRUE if the A-device detects that VBUS is above VA_SESS_VLD
90  * @b_bus_suspend: TRUE when the A-device detects that the B-device has put
91  *		the bus into suspend
92  * @b_bus_resume: TRUE when the A-device detects that the B-device is signaling
93  *		 resume on the bus
94  *
95  * OTG Output status. Read only for users. Updated by OTG FSM helpers defined
96  * in this file
97  *
98  *	Outputs for Both A and B device
99  * @drv_vbus:	TRUE when A-device is driving VBUS
100  * @loc_conn:	TRUE when the local device has signaled that it is connected
101  *		to the bus
102  * @loc_sof:	TRUE when the local device is generating activity on the bus
103  * @adp_prb:	TRUE when the local device is in the process of doing
104  *		ADP probing
105  *
106  *	Outputs for B-device state
107  * @adp_sns:	TRUE when the B-device is in the process of carrying out
108  *		ADP sensing
109  * @data_pulse: TRUE when the B-device is performing data line pulsing
110  *
111  * Internal Variables
112  *
113  * a_set_b_hnp_en: TRUE when the A-device has successfully set the
114  *		b_hnp_enable bit in the B-device.
115  *		   Unused as OTG fsm uses otg->host->b_hnp_enable instead
116  * b_srp_done:	TRUE when the B-device has completed initiating SRP
117  * b_hnp_enable: TRUE when the B-device has accepted the
118  *		SetFeature(b_hnp_enable) B-device.
119  *		Unused as OTG fsm uses otg->gadget->b_hnp_enable instead
120  * a_clr_err:	Asserted (by application ?) to clear a_vbus_err due to an
121  *		overcurrent condition and causes the A-device to transition
122  *		to a_wait_vfall
123  */
124 struct otg_fsm {
125 	/* Input */
126 	int id;
127 	int adp_change;
128 	int power_up;
129 	int a_srp_det;
130 	int a_vbus_vld;
131 	int b_conn;
132 	int a_bus_resume;
133 	int a_bus_suspend;
134 	int a_conn;
135 	int b_se0_srp;
136 	int b_ssend_srp;
137 	int b_sess_vld;
138 	int test_device;
139 	int a_bus_drop;
140 	int a_bus_req;
141 	int b_bus_req;
142 
143 	/* Auxiliary inputs */
144 	int a_sess_vld;
145 	int b_bus_resume;
146 	int b_bus_suspend;
147 
148 	/* Output */
149 	int drv_vbus;
150 	int loc_conn;
151 	int loc_sof;
152 	int adp_prb;
153 	int adp_sns;
154 	int data_pulse;
155 
156 	/* Internal variables */
157 	int a_set_b_hnp_en;
158 	int b_srp_done;
159 	int b_hnp_enable;
160 	int a_clr_err;
161 
162 	/* Informative variables. All unused as of now */
163 	int a_bus_drop_inf;
164 	int a_bus_req_inf;
165 	int a_clr_err_inf;
166 	int b_bus_req_inf;
167 	/* Auxiliary informative variables */
168 	int a_suspend_req_inf;
169 
170 	/* Timeout indicator for timers */
171 	int a_wait_vrise_tmout;
172 	int a_wait_vfall_tmout;
173 	int a_wait_bcon_tmout;
174 	int a_aidl_bdis_tmout;
175 	int b_ase0_brst_tmout;
176 	int a_bidl_adis_tmout;
177 
178 	struct otg_fsm_ops *ops;
179 	struct usb_otg *otg;
180 
181 	/* Current usb protocol used: 0:undefine; 1:host; 2:client */
182 	int protocol;
183 	struct mutex lock;
184 	u8 *host_req_flag;
185 	struct delayed_work hnp_polling_work;
186 	bool hnp_work_inited;
187 	bool state_changed;
188 };
189 
190 struct otg_fsm_ops {
191 	void	(*chrg_vbus)(struct otg_fsm *fsm, int on);
192 	void	(*drv_vbus)(struct otg_fsm *fsm, int on);
193 	void	(*loc_conn)(struct otg_fsm *fsm, int on);
194 	void	(*loc_sof)(struct otg_fsm *fsm, int on);
195 	void	(*start_pulse)(struct otg_fsm *fsm);
196 	void	(*start_adp_prb)(struct otg_fsm *fsm);
197 	void	(*start_adp_sns)(struct otg_fsm *fsm);
198 	void	(*add_timer)(struct otg_fsm *fsm, enum otg_fsm_timer timer);
199 	void	(*del_timer)(struct otg_fsm *fsm, enum otg_fsm_timer timer);
200 	int	(*start_host)(struct otg_fsm *fsm, int on);
201 	int	(*start_gadget)(struct otg_fsm *fsm, int on);
202 };
203 
204 
otg_chrg_vbus(struct otg_fsm * fsm,int on)205 static inline int otg_chrg_vbus(struct otg_fsm *fsm, int on)
206 {
207 	if (!fsm->ops->chrg_vbus)
208 		return -EOPNOTSUPP;
209 	fsm->ops->chrg_vbus(fsm, on);
210 	return 0;
211 }
212 
otg_drv_vbus(struct otg_fsm * fsm,int on)213 static inline int otg_drv_vbus(struct otg_fsm *fsm, int on)
214 {
215 	if (!fsm->ops->drv_vbus)
216 		return -EOPNOTSUPP;
217 	if (fsm->drv_vbus != on) {
218 		fsm->drv_vbus = on;
219 		fsm->ops->drv_vbus(fsm, on);
220 	}
221 	return 0;
222 }
223 
otg_loc_conn(struct otg_fsm * fsm,int on)224 static inline int otg_loc_conn(struct otg_fsm *fsm, int on)
225 {
226 	if (!fsm->ops->loc_conn)
227 		return -EOPNOTSUPP;
228 	if (fsm->loc_conn != on) {
229 		fsm->loc_conn = on;
230 		fsm->ops->loc_conn(fsm, on);
231 	}
232 	return 0;
233 }
234 
otg_loc_sof(struct otg_fsm * fsm,int on)235 static inline int otg_loc_sof(struct otg_fsm *fsm, int on)
236 {
237 	if (!fsm->ops->loc_sof)
238 		return -EOPNOTSUPP;
239 	if (fsm->loc_sof != on) {
240 		fsm->loc_sof = on;
241 		fsm->ops->loc_sof(fsm, on);
242 	}
243 	return 0;
244 }
245 
otg_start_pulse(struct otg_fsm * fsm)246 static inline int otg_start_pulse(struct otg_fsm *fsm)
247 {
248 	if (!fsm->ops->start_pulse)
249 		return -EOPNOTSUPP;
250 	if (!fsm->data_pulse) {
251 		fsm->data_pulse = 1;
252 		fsm->ops->start_pulse(fsm);
253 	}
254 	return 0;
255 }
256 
otg_start_adp_prb(struct otg_fsm * fsm)257 static inline int otg_start_adp_prb(struct otg_fsm *fsm)
258 {
259 	if (!fsm->ops->start_adp_prb)
260 		return -EOPNOTSUPP;
261 	if (!fsm->adp_prb) {
262 		fsm->adp_sns = 0;
263 		fsm->adp_prb = 1;
264 		fsm->ops->start_adp_prb(fsm);
265 	}
266 	return 0;
267 }
268 
otg_start_adp_sns(struct otg_fsm * fsm)269 static inline int otg_start_adp_sns(struct otg_fsm *fsm)
270 {
271 	if (!fsm->ops->start_adp_sns)
272 		return -EOPNOTSUPP;
273 	if (!fsm->adp_sns) {
274 		fsm->adp_sns = 1;
275 		fsm->ops->start_adp_sns(fsm);
276 	}
277 	return 0;
278 }
279 
otg_add_timer(struct otg_fsm * fsm,enum otg_fsm_timer timer)280 static inline int otg_add_timer(struct otg_fsm *fsm, enum otg_fsm_timer timer)
281 {
282 	if (!fsm->ops->add_timer)
283 		return -EOPNOTSUPP;
284 	fsm->ops->add_timer(fsm, timer);
285 	return 0;
286 }
287 
otg_del_timer(struct otg_fsm * fsm,enum otg_fsm_timer timer)288 static inline int otg_del_timer(struct otg_fsm *fsm, enum otg_fsm_timer timer)
289 {
290 	if (!fsm->ops->del_timer)
291 		return -EOPNOTSUPP;
292 	fsm->ops->del_timer(fsm, timer);
293 	return 0;
294 }
295 
otg_start_host(struct otg_fsm * fsm,int on)296 static inline int otg_start_host(struct otg_fsm *fsm, int on)
297 {
298 	if (!fsm->ops->start_host)
299 		return -EOPNOTSUPP;
300 	return fsm->ops->start_host(fsm, on);
301 }
302 
otg_start_gadget(struct otg_fsm * fsm,int on)303 static inline int otg_start_gadget(struct otg_fsm *fsm, int on)
304 {
305 	if (!fsm->ops->start_gadget)
306 		return -EOPNOTSUPP;
307 	return fsm->ops->start_gadget(fsm, on);
308 }
309 
310 int otg_statemachine(struct otg_fsm *fsm);
311 
312 #endif /* __LINUX_USB_OTG_FSM_H */
313