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