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1/*
2 * OTG Finite State Machine from OTG spec
3 *
4 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
5 *
6 * Author: Li Yang <LeoLi@freescale.com>
7 * Jerry Huang <Chang-Ming.Huang@freescale.com>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the
11 * Free Software Foundation; either version 2 of the License, or (at your
12 * option) any later version.
13 *
14 * This program is distributed in the hope that it will be useful, but
15 * WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 *
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 675 Mass Ave, Cambridge, MA 02139, USA.
22 */
23
24#include <linux/kernel.h>
25#include <linux/types.h>
26#include <linux/mutex.h>
27#include <linux/delay.h>
28#include <linux/usb.h>
29#include <linux/usb/gadget.h>
30#include <linux/usb/otg.h>
31#include <linux/usb/otg-fsm.h>
32
33/* Change USB protocol when there is a protocol change */
34static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
35{
36 int ret = 0;
37
38 if (fsm->protocol != protocol) {
39 VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
40 fsm->protocol, protocol);
41 /* stop old protocol */
42 if (fsm->protocol == PROTO_HOST)
43 ret = otg_start_host(fsm, 0);
44 else if (fsm->protocol == PROTO_GADGET)
45 ret = otg_start_gadget(fsm, 0);
46 if (ret)
47 return ret;
48
49 /* start new protocol */
50 if (protocol == PROTO_HOST)
51 ret = otg_start_host(fsm, 1);
52 else if (protocol == PROTO_GADGET)
53 ret = otg_start_gadget(fsm, 1);
54 if (ret)
55 return ret;
56
57 fsm->protocol = protocol;
58 return 0;
59 }
60
61 return 0;
62}
63
64static int state_changed;
65
66/* Called when leaving a state. Do state clean up jobs here */
67static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
68{
69 switch (old_state) {
70 case OTG_STATE_B_IDLE:
71 otg_del_timer(fsm, B_SE0_SRP);
72 fsm->b_se0_srp = 0;
73 fsm->adp_sns = 0;
74 fsm->adp_prb = 0;
75 break;
76 case OTG_STATE_B_SRP_INIT:
77 fsm->data_pulse = 0;
78 fsm->b_srp_done = 0;
79 break;
80 case OTG_STATE_B_PERIPHERAL:
81 if (fsm->otg->gadget)
82 fsm->otg->gadget->host_request_flag = 0;
83 break;
84 case OTG_STATE_B_WAIT_ACON:
85 otg_del_timer(fsm, B_ASE0_BRST);
86 fsm->b_ase0_brst_tmout = 0;
87 break;
88 case OTG_STATE_B_HOST:
89 break;
90 case OTG_STATE_A_IDLE:
91 fsm->adp_prb = 0;
92 break;
93 case OTG_STATE_A_WAIT_VRISE:
94 otg_del_timer(fsm, A_WAIT_VRISE);
95 fsm->a_wait_vrise_tmout = 0;
96 break;
97 case OTG_STATE_A_WAIT_BCON:
98 otg_del_timer(fsm, A_WAIT_BCON);
99 fsm->a_wait_bcon_tmout = 0;
100 break;
101 case OTG_STATE_A_HOST:
102 otg_del_timer(fsm, A_WAIT_ENUM);
103 break;
104 case OTG_STATE_A_SUSPEND:
105 otg_del_timer(fsm, A_AIDL_BDIS);
106 fsm->a_aidl_bdis_tmout = 0;
107 fsm->a_suspend_req_inf = 0;
108 break;
109 case OTG_STATE_A_PERIPHERAL:
110 otg_del_timer(fsm, A_BIDL_ADIS);
111 fsm->a_bidl_adis_tmout = 0;
112 if (fsm->otg->gadget)
113 fsm->otg->gadget->host_request_flag = 0;
114 break;
115 case OTG_STATE_A_WAIT_VFALL:
116 otg_del_timer(fsm, A_WAIT_VFALL);
117 fsm->a_wait_vfall_tmout = 0;
118 otg_del_timer(fsm, A_WAIT_VRISE);
119 break;
120 case OTG_STATE_A_VBUS_ERR:
121 break;
122 default:
123 break;
124 }
125}
126
127static void otg_hnp_polling_work(struct work_struct *work)
128{
129 struct otg_fsm *fsm = container_of(to_delayed_work(work),
130 struct otg_fsm, hnp_polling_work);
131 struct usb_device *udev;
132 enum usb_otg_state state = fsm->otg->state;
133 u8 flag;
134 int retval;
135
136 if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
137 return;
138
139 udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
140 if (!udev) {
141 dev_err(fsm->otg->host->controller,
142 "no usb dev connected, can't start HNP polling\n");
143 return;
144 }
145
146 *fsm->host_req_flag = 0;
147 /* Get host request flag from connected USB device */
148 retval = usb_control_msg(udev,
149 usb_rcvctrlpipe(udev, 0),
150 USB_REQ_GET_STATUS,
151 USB_DIR_IN | USB_RECIP_DEVICE,
152 0,
153 OTG_STS_SELECTOR,
154 fsm->host_req_flag,
155 1,
156 USB_CTRL_GET_TIMEOUT);
157 if (retval != 1) {
158 dev_err(&udev->dev, "Get one byte OTG status failed\n");
159 return;
160 }
161
162 flag = *fsm->host_req_flag;
163 if (flag == 0) {
164 /* Continue HNP polling */
165 schedule_delayed_work(&fsm->hnp_polling_work,
166 msecs_to_jiffies(T_HOST_REQ_POLL));
167 return;
168 } else if (flag != HOST_REQUEST_FLAG) {
169 dev_err(&udev->dev, "host request flag %d is invalid\n", flag);
170 return;
171 }
172
173 /* Host request flag is set */
174 if (state == OTG_STATE_A_HOST) {
175 /* Set b_hnp_enable */
176 if (!fsm->otg->host->b_hnp_enable) {
177 retval = usb_control_msg(udev,
178 usb_sndctrlpipe(udev, 0),
179 USB_REQ_SET_FEATURE, 0,
180 USB_DEVICE_B_HNP_ENABLE,
181 0, NULL, 0,
182 USB_CTRL_SET_TIMEOUT);
183 if (retval >= 0)
184 fsm->otg->host->b_hnp_enable = 1;
185 }
186 fsm->a_bus_req = 0;
187 } else if (state == OTG_STATE_B_HOST) {
188 fsm->b_bus_req = 0;
189 }
190
191 otg_statemachine(fsm);
192}
193
194static void otg_start_hnp_polling(struct otg_fsm *fsm)
195{
196 /*
197 * The memory of host_req_flag should be allocated by
198 * controller driver, otherwise, hnp polling is not started.
199 */
200 if (!fsm->host_req_flag)
201 return;
202
203 INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
204 schedule_delayed_work(&fsm->hnp_polling_work,
205 msecs_to_jiffies(T_HOST_REQ_POLL));
206}
207
208/* Called when entering a state */
209static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
210{
211 state_changed = 1;
212 if (fsm->otg->state == new_state)
213 return 0;
214 VDBG("Set state: %s\n", usb_otg_state_string(new_state));
215 otg_leave_state(fsm, fsm->otg->state);
216 switch (new_state) {
217 case OTG_STATE_B_IDLE:
218 otg_drv_vbus(fsm, 0);
219 otg_chrg_vbus(fsm, 0);
220 otg_loc_conn(fsm, 0);
221 otg_loc_sof(fsm, 0);
222 /*
223 * Driver is responsible for starting ADP probing
224 * if ADP sensing times out.
225 */
226 otg_start_adp_sns(fsm);
227 otg_set_protocol(fsm, PROTO_UNDEF);
228 otg_add_timer(fsm, B_SE0_SRP);
229 break;
230 case OTG_STATE_B_SRP_INIT:
231 otg_start_pulse(fsm);
232 otg_loc_sof(fsm, 0);
233 otg_set_protocol(fsm, PROTO_UNDEF);
234 otg_add_timer(fsm, B_SRP_FAIL);
235 break;
236 case OTG_STATE_B_PERIPHERAL:
237 otg_chrg_vbus(fsm, 0);
238 otg_loc_sof(fsm, 0);
239 otg_set_protocol(fsm, PROTO_GADGET);
240 otg_loc_conn(fsm, 1);
241 break;
242 case OTG_STATE_B_WAIT_ACON:
243 otg_chrg_vbus(fsm, 0);
244 otg_loc_conn(fsm, 0);
245 otg_loc_sof(fsm, 0);
246 otg_set_protocol(fsm, PROTO_HOST);
247 otg_add_timer(fsm, B_ASE0_BRST);
248 fsm->a_bus_suspend = 0;
249 break;
250 case OTG_STATE_B_HOST:
251 otg_chrg_vbus(fsm, 0);
252 otg_loc_conn(fsm, 0);
253 otg_loc_sof(fsm, 1);
254 otg_set_protocol(fsm, PROTO_HOST);
255 usb_bus_start_enum(fsm->otg->host,
256 fsm->otg->host->otg_port);
257 otg_start_hnp_polling(fsm);
258 break;
259 case OTG_STATE_A_IDLE:
260 otg_drv_vbus(fsm, 0);
261 otg_chrg_vbus(fsm, 0);
262 otg_loc_conn(fsm, 0);
263 otg_loc_sof(fsm, 0);
264 otg_start_adp_prb(fsm);
265 otg_set_protocol(fsm, PROTO_HOST);
266 break;
267 case OTG_STATE_A_WAIT_VRISE:
268 otg_drv_vbus(fsm, 1);
269 otg_loc_conn(fsm, 0);
270 otg_loc_sof(fsm, 0);
271 otg_set_protocol(fsm, PROTO_HOST);
272 otg_add_timer(fsm, A_WAIT_VRISE);
273 break;
274 case OTG_STATE_A_WAIT_BCON:
275 otg_drv_vbus(fsm, 1);
276 otg_loc_conn(fsm, 0);
277 otg_loc_sof(fsm, 0);
278 otg_set_protocol(fsm, PROTO_HOST);
279 otg_add_timer(fsm, A_WAIT_BCON);
280 break;
281 case OTG_STATE_A_HOST:
282 otg_drv_vbus(fsm, 1);
283 otg_loc_conn(fsm, 0);
284 otg_loc_sof(fsm, 1);
285 otg_set_protocol(fsm, PROTO_HOST);
286 /*
287 * When HNP is triggered while a_bus_req = 0, a_host will
288 * suspend too fast to complete a_set_b_hnp_en
289 */
290 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
291 otg_add_timer(fsm, A_WAIT_ENUM);
292 otg_start_hnp_polling(fsm);
293 break;
294 case OTG_STATE_A_SUSPEND:
295 otg_drv_vbus(fsm, 1);
296 otg_loc_conn(fsm, 0);
297 otg_loc_sof(fsm, 0);
298 otg_set_protocol(fsm, PROTO_HOST);
299 otg_add_timer(fsm, A_AIDL_BDIS);
300
301 break;
302 case OTG_STATE_A_PERIPHERAL:
303 otg_loc_sof(fsm, 0);
304 otg_set_protocol(fsm, PROTO_GADGET);
305 otg_drv_vbus(fsm, 1);
306 otg_loc_conn(fsm, 1);
307 otg_add_timer(fsm, A_BIDL_ADIS);
308 break;
309 case OTG_STATE_A_WAIT_VFALL:
310 otg_drv_vbus(fsm, 0);
311 otg_loc_conn(fsm, 0);
312 otg_loc_sof(fsm, 0);
313 otg_set_protocol(fsm, PROTO_HOST);
314 otg_add_timer(fsm, A_WAIT_VFALL);
315 break;
316 case OTG_STATE_A_VBUS_ERR:
317 otg_drv_vbus(fsm, 0);
318 otg_loc_conn(fsm, 0);
319 otg_loc_sof(fsm, 0);
320 otg_set_protocol(fsm, PROTO_UNDEF);
321 break;
322 default:
323 break;
324 }
325
326 fsm->otg->state = new_state;
327 return 0;
328}
329
330/* State change judgement */
331int otg_statemachine(struct otg_fsm *fsm)
332{
333 enum usb_otg_state state;
334
335 mutex_lock(&fsm->lock);
336
337 state = fsm->otg->state;
338 state_changed = 0;
339 /* State machine state change judgement */
340
341 switch (state) {
342 case OTG_STATE_UNDEFINED:
343 VDBG("fsm->id = %d\n", fsm->id);
344 if (fsm->id)
345 otg_set_state(fsm, OTG_STATE_B_IDLE);
346 else
347 otg_set_state(fsm, OTG_STATE_A_IDLE);
348 break;
349 case OTG_STATE_B_IDLE:
350 if (!fsm->id)
351 otg_set_state(fsm, OTG_STATE_A_IDLE);
352 else if (fsm->b_sess_vld && fsm->otg->gadget)
353 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
354 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
355 fsm->b_ssend_srp && fsm->b_se0_srp)
356 otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
357 break;
358 case OTG_STATE_B_SRP_INIT:
359 if (!fsm->id || fsm->b_srp_done)
360 otg_set_state(fsm, OTG_STATE_B_IDLE);
361 break;
362 case OTG_STATE_B_PERIPHERAL:
363 if (!fsm->id || !fsm->b_sess_vld)
364 otg_set_state(fsm, OTG_STATE_B_IDLE);
365 else if (fsm->b_bus_req && fsm->otg->
366 gadget->b_hnp_enable && fsm->a_bus_suspend)
367 otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
368 break;
369 case OTG_STATE_B_WAIT_ACON:
370 if (fsm->a_conn)
371 otg_set_state(fsm, OTG_STATE_B_HOST);
372 else if (!fsm->id || !fsm->b_sess_vld)
373 otg_set_state(fsm, OTG_STATE_B_IDLE);
374 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
375 fsm->b_ase0_brst_tmout = 0;
376 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
377 }
378 break;
379 case OTG_STATE_B_HOST:
380 if (!fsm->id || !fsm->b_sess_vld)
381 otg_set_state(fsm, OTG_STATE_B_IDLE);
382 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
383 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
384 break;
385 case OTG_STATE_A_IDLE:
386 if (fsm->id)
387 otg_set_state(fsm, OTG_STATE_B_IDLE);
388 else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
389 fsm->a_srp_det || fsm->adp_change || fsm->power_up))
390 otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
391 break;
392 case OTG_STATE_A_WAIT_VRISE:
393 if (fsm->a_vbus_vld)
394 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
395 else if (fsm->id || fsm->a_bus_drop ||
396 fsm->a_wait_vrise_tmout)
397 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
398 break;
399 case OTG_STATE_A_WAIT_BCON:
400 if (!fsm->a_vbus_vld)
401 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
402 else if (fsm->b_conn)
403 otg_set_state(fsm, OTG_STATE_A_HOST);
404 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
405 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
406 break;
407 case OTG_STATE_A_HOST:
408 if (fsm->id || fsm->a_bus_drop)
409 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
410 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
411 fsm->otg->host->b_hnp_enable)
412 otg_set_state(fsm, OTG_STATE_A_SUSPEND);
413 else if (!fsm->b_conn)
414 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
415 else if (!fsm->a_vbus_vld)
416 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
417 break;
418 case OTG_STATE_A_SUSPEND:
419 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
420 otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
421 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
422 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
423 else if (fsm->a_bus_req || fsm->b_bus_resume)
424 otg_set_state(fsm, OTG_STATE_A_HOST);
425 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
426 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
427 else if (!fsm->a_vbus_vld)
428 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
429 break;
430 case OTG_STATE_A_PERIPHERAL:
431 if (fsm->id || fsm->a_bus_drop)
432 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
433 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
434 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
435 else if (!fsm->a_vbus_vld)
436 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
437 break;
438 case OTG_STATE_A_WAIT_VFALL:
439 if (fsm->a_wait_vfall_tmout)
440 otg_set_state(fsm, OTG_STATE_A_IDLE);
441 break;
442 case OTG_STATE_A_VBUS_ERR:
443 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
444 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
445 break;
446 default:
447 break;
448 }
449 mutex_unlock(&fsm->lock);
450
451 VDBG("quit statemachine, changed = %d\n", state_changed);
452 return state_changed;
453}
454EXPORT_SYMBOL_GPL(otg_statemachine);