2 * OTG Finite State Machine from OTG spec
4 * Copyright (C) 2007,2008 Freescale Semiconductor, Inc.
6 * Author: Li Yang <LeoLi@freescale.com>
7 * Jerry Huang <Chang-Ming.Huang@freescale.com>
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.
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.
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.
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>
34 /* Change USB protocol when there is a protocol change */
35 static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
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);
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);
58 fsm->protocol = protocol;
65 /* Called when leaving a state. Do state clean up jobs here */
66 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
69 case OTG_STATE_B_IDLE:
70 otg_del_timer(fsm, B_SE0_SRP);
75 case OTG_STATE_B_SRP_INIT:
79 case OTG_STATE_B_PERIPHERAL:
81 fsm->otg->gadget->host_request_flag = 0;
83 case OTG_STATE_B_WAIT_ACON:
84 otg_del_timer(fsm, B_ASE0_BRST);
85 fsm->b_ase0_brst_tmout = 0;
87 case OTG_STATE_B_HOST:
89 case OTG_STATE_A_IDLE:
92 case OTG_STATE_A_WAIT_VRISE:
93 otg_del_timer(fsm, A_WAIT_VRISE);
94 fsm->a_wait_vrise_tmout = 0;
96 case OTG_STATE_A_WAIT_BCON:
97 otg_del_timer(fsm, A_WAIT_BCON);
98 fsm->a_wait_bcon_tmout = 0;
100 case OTG_STATE_A_HOST:
101 otg_del_timer(fsm, A_WAIT_ENUM);
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;
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;
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);
119 case OTG_STATE_A_VBUS_ERR:
126 static void otg_hnp_polling_work(struct work_struct *work)
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;
135 if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
138 udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
140 dev_err(fsm->otg->host->controller,
141 "no usb dev connected, can't start HNP polling\n");
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),
150 USB_DIR_IN | USB_RECIP_DEVICE,
155 USB_CTRL_GET_TIMEOUT);
157 dev_err(&udev->dev, "Get one byte OTG status failed\n");
161 flag = *fsm->host_req_flag;
163 /* Continue HNP polling */
164 schedule_delayed_work(&fsm->hnp_polling_work,
165 msecs_to_jiffies(T_HOST_REQ_POLL));
167 } else if (flag != HOST_REQUEST_FLAG) {
168 dev_err(&udev->dev, "host request flag %d is invalid\n", flag);
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,
181 USB_CTRL_SET_TIMEOUT);
183 fsm->otg->host->b_hnp_enable = 1;
186 } else if (state == OTG_STATE_B_HOST) {
190 otg_statemachine(fsm);
193 static void otg_start_hnp_polling(struct otg_fsm *fsm)
196 * The memory of host_req_flag should be allocated by
197 * controller driver, otherwise, hnp polling is not started.
199 if (!fsm->host_req_flag)
202 if (!fsm->hnp_work_inited) {
203 INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
204 fsm->hnp_work_inited = true;
207 schedule_delayed_work(&fsm->hnp_polling_work,
208 msecs_to_jiffies(T_HOST_REQ_POLL));
211 /* Called when entering a state */
212 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
214 if (fsm->otg->state == new_state)
216 VDBG("Set state: %s\n", usb_otg_state_string(new_state));
217 otg_leave_state(fsm, fsm->otg->state);
219 case OTG_STATE_B_IDLE:
220 otg_drv_vbus(fsm, 0);
221 otg_chrg_vbus(fsm, 0);
222 otg_loc_conn(fsm, 0);
225 * Driver is responsible for starting ADP probing
226 * if ADP sensing times out.
228 otg_start_adp_sns(fsm);
229 otg_set_protocol(fsm, PROTO_UNDEF);
230 otg_add_timer(fsm, B_SE0_SRP);
232 case OTG_STATE_B_SRP_INIT:
233 otg_start_pulse(fsm);
235 otg_set_protocol(fsm, PROTO_UNDEF);
236 otg_add_timer(fsm, B_SRP_FAIL);
238 case OTG_STATE_B_PERIPHERAL:
239 otg_chrg_vbus(fsm, 0);
241 otg_set_protocol(fsm, PROTO_GADGET);
242 otg_loc_conn(fsm, 1);
244 case OTG_STATE_B_WAIT_ACON:
245 otg_chrg_vbus(fsm, 0);
246 otg_loc_conn(fsm, 0);
248 otg_set_protocol(fsm, PROTO_HOST);
249 otg_add_timer(fsm, B_ASE0_BRST);
250 fsm->a_bus_suspend = 0;
252 case OTG_STATE_B_HOST:
253 otg_chrg_vbus(fsm, 0);
254 otg_loc_conn(fsm, 0);
256 otg_set_protocol(fsm, PROTO_HOST);
257 usb_bus_start_enum(fsm->otg->host,
258 fsm->otg->host->otg_port);
259 otg_start_hnp_polling(fsm);
261 case OTG_STATE_A_IDLE:
262 otg_drv_vbus(fsm, 0);
263 otg_chrg_vbus(fsm, 0);
264 otg_loc_conn(fsm, 0);
266 otg_start_adp_prb(fsm);
267 otg_set_protocol(fsm, PROTO_HOST);
269 case OTG_STATE_A_WAIT_VRISE:
270 otg_drv_vbus(fsm, 1);
271 otg_loc_conn(fsm, 0);
273 otg_set_protocol(fsm, PROTO_HOST);
274 otg_add_timer(fsm, A_WAIT_VRISE);
276 case OTG_STATE_A_WAIT_BCON:
277 otg_drv_vbus(fsm, 1);
278 otg_loc_conn(fsm, 0);
280 otg_set_protocol(fsm, PROTO_HOST);
281 otg_add_timer(fsm, A_WAIT_BCON);
283 case OTG_STATE_A_HOST:
284 otg_drv_vbus(fsm, 1);
285 otg_loc_conn(fsm, 0);
287 otg_set_protocol(fsm, PROTO_HOST);
289 * When HNP is triggered while a_bus_req = 0, a_host will
290 * suspend too fast to complete a_set_b_hnp_en
292 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
293 otg_add_timer(fsm, A_WAIT_ENUM);
294 otg_start_hnp_polling(fsm);
296 case OTG_STATE_A_SUSPEND:
297 otg_drv_vbus(fsm, 1);
298 otg_loc_conn(fsm, 0);
300 otg_set_protocol(fsm, PROTO_HOST);
301 otg_add_timer(fsm, A_AIDL_BDIS);
304 case OTG_STATE_A_PERIPHERAL:
306 otg_set_protocol(fsm, PROTO_GADGET);
307 otg_drv_vbus(fsm, 1);
308 otg_loc_conn(fsm, 1);
309 otg_add_timer(fsm, A_BIDL_ADIS);
311 case OTG_STATE_A_WAIT_VFALL:
312 otg_drv_vbus(fsm, 0);
313 otg_loc_conn(fsm, 0);
315 otg_set_protocol(fsm, PROTO_HOST);
316 otg_add_timer(fsm, A_WAIT_VFALL);
318 case OTG_STATE_A_VBUS_ERR:
319 otg_drv_vbus(fsm, 0);
320 otg_loc_conn(fsm, 0);
322 otg_set_protocol(fsm, PROTO_UNDEF);
328 fsm->otg->state = new_state;
329 fsm->state_changed = 1;
333 /* State change judgement */
334 int otg_statemachine(struct otg_fsm *fsm)
336 enum usb_otg_state state;
338 mutex_lock(&fsm->lock);
340 state = fsm->otg->state;
341 fsm->state_changed = 0;
342 /* State machine state change judgement */
345 case OTG_STATE_UNDEFINED:
346 VDBG("fsm->id = %d\n", fsm->id);
348 otg_set_state(fsm, OTG_STATE_B_IDLE);
350 otg_set_state(fsm, OTG_STATE_A_IDLE);
352 case OTG_STATE_B_IDLE:
354 otg_set_state(fsm, OTG_STATE_A_IDLE);
355 else if (fsm->b_sess_vld && fsm->otg->gadget)
356 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
357 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
358 fsm->b_ssend_srp && fsm->b_se0_srp)
359 otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
361 case OTG_STATE_B_SRP_INIT:
362 if (!fsm->id || fsm->b_srp_done)
363 otg_set_state(fsm, OTG_STATE_B_IDLE);
365 case OTG_STATE_B_PERIPHERAL:
366 if (!fsm->id || !fsm->b_sess_vld)
367 otg_set_state(fsm, OTG_STATE_B_IDLE);
368 else if (fsm->b_bus_req && fsm->otg->
369 gadget->b_hnp_enable && fsm->a_bus_suspend)
370 otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
372 case OTG_STATE_B_WAIT_ACON:
374 otg_set_state(fsm, OTG_STATE_B_HOST);
375 else if (!fsm->id || !fsm->b_sess_vld)
376 otg_set_state(fsm, OTG_STATE_B_IDLE);
377 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
378 fsm->b_ase0_brst_tmout = 0;
379 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
382 case OTG_STATE_B_HOST:
383 if (!fsm->id || !fsm->b_sess_vld)
384 otg_set_state(fsm, OTG_STATE_B_IDLE);
385 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
386 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
388 case OTG_STATE_A_IDLE:
390 otg_set_state(fsm, OTG_STATE_B_IDLE);
391 else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
392 fsm->a_srp_det || fsm->adp_change || fsm->power_up))
393 otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
395 case OTG_STATE_A_WAIT_VRISE:
397 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
398 else if (fsm->id || fsm->a_bus_drop ||
399 fsm->a_wait_vrise_tmout)
400 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
402 case OTG_STATE_A_WAIT_BCON:
403 if (!fsm->a_vbus_vld)
404 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
405 else if (fsm->b_conn)
406 otg_set_state(fsm, OTG_STATE_A_HOST);
407 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
408 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
410 case OTG_STATE_A_HOST:
411 if (fsm->id || fsm->a_bus_drop)
412 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
413 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
414 fsm->otg->host->b_hnp_enable)
415 otg_set_state(fsm, OTG_STATE_A_SUSPEND);
416 else if (!fsm->b_conn)
417 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
418 else if (!fsm->a_vbus_vld)
419 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
421 case OTG_STATE_A_SUSPEND:
422 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
423 otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
424 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
425 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
426 else if (fsm->a_bus_req || fsm->b_bus_resume)
427 otg_set_state(fsm, OTG_STATE_A_HOST);
428 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
429 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
430 else if (!fsm->a_vbus_vld)
431 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
433 case OTG_STATE_A_PERIPHERAL:
434 if (fsm->id || fsm->a_bus_drop)
435 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
436 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
437 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
438 else if (!fsm->a_vbus_vld)
439 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
441 case OTG_STATE_A_WAIT_VFALL:
442 if (fsm->a_wait_vfall_tmout)
443 otg_set_state(fsm, OTG_STATE_A_IDLE);
445 case OTG_STATE_A_VBUS_ERR:
446 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
447 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
452 mutex_unlock(&fsm->lock);
454 VDBG("quit statemachine, changed = %d\n", fsm->state_changed);
455 return fsm->state_changed;
457 EXPORT_SYMBOL_GPL(otg_statemachine);
458 MODULE_LICENSE("GPL");