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 static int state_changed;
67 /* Called when leaving a state. Do state clean up jobs here */
68 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
71 case OTG_STATE_B_IDLE:
72 otg_del_timer(fsm, B_SE0_SRP);
77 case OTG_STATE_B_SRP_INIT:
81 case OTG_STATE_B_PERIPHERAL:
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;
112 case OTG_STATE_A_WAIT_VFALL:
113 otg_del_timer(fsm, A_WAIT_VFALL);
114 fsm->a_wait_vfall_tmout = 0;
115 otg_del_timer(fsm, A_WAIT_VRISE);
117 case OTG_STATE_A_VBUS_ERR:
124 /* Called when entering a state */
125 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
128 if (fsm->otg->state == new_state)
130 VDBG("Set state: %s\n", usb_otg_state_string(new_state));
131 otg_leave_state(fsm, fsm->otg->state);
133 case OTG_STATE_B_IDLE:
134 otg_drv_vbus(fsm, 0);
135 otg_chrg_vbus(fsm, 0);
136 otg_loc_conn(fsm, 0);
139 * Driver is responsible for starting ADP probing
140 * if ADP sensing times out.
142 otg_start_adp_sns(fsm);
143 otg_set_protocol(fsm, PROTO_UNDEF);
144 otg_add_timer(fsm, B_SE0_SRP);
146 case OTG_STATE_B_SRP_INIT:
147 otg_start_pulse(fsm);
149 otg_set_protocol(fsm, PROTO_UNDEF);
150 otg_add_timer(fsm, B_SRP_FAIL);
152 case OTG_STATE_B_PERIPHERAL:
153 otg_chrg_vbus(fsm, 0);
155 otg_set_protocol(fsm, PROTO_GADGET);
156 otg_loc_conn(fsm, 1);
158 case OTG_STATE_B_WAIT_ACON:
159 otg_chrg_vbus(fsm, 0);
160 otg_loc_conn(fsm, 0);
162 otg_set_protocol(fsm, PROTO_HOST);
163 otg_add_timer(fsm, B_ASE0_BRST);
164 fsm->a_bus_suspend = 0;
166 case OTG_STATE_B_HOST:
167 otg_chrg_vbus(fsm, 0);
168 otg_loc_conn(fsm, 0);
170 otg_set_protocol(fsm, PROTO_HOST);
171 usb_bus_start_enum(fsm->otg->host,
172 fsm->otg->host->otg_port);
174 case OTG_STATE_A_IDLE:
175 otg_drv_vbus(fsm, 0);
176 otg_chrg_vbus(fsm, 0);
177 otg_loc_conn(fsm, 0);
179 otg_start_adp_prb(fsm);
180 otg_set_protocol(fsm, PROTO_HOST);
182 case OTG_STATE_A_WAIT_VRISE:
183 otg_drv_vbus(fsm, 1);
184 otg_loc_conn(fsm, 0);
186 otg_set_protocol(fsm, PROTO_HOST);
187 otg_add_timer(fsm, A_WAIT_VRISE);
189 case OTG_STATE_A_WAIT_BCON:
190 otg_drv_vbus(fsm, 1);
191 otg_loc_conn(fsm, 0);
193 otg_set_protocol(fsm, PROTO_HOST);
194 otg_add_timer(fsm, A_WAIT_BCON);
196 case OTG_STATE_A_HOST:
197 otg_drv_vbus(fsm, 1);
198 otg_loc_conn(fsm, 0);
200 otg_set_protocol(fsm, PROTO_HOST);
202 * When HNP is triggered while a_bus_req = 0, a_host will
203 * suspend too fast to complete a_set_b_hnp_en
205 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
206 otg_add_timer(fsm, A_WAIT_ENUM);
208 case OTG_STATE_A_SUSPEND:
209 otg_drv_vbus(fsm, 1);
210 otg_loc_conn(fsm, 0);
212 otg_set_protocol(fsm, PROTO_HOST);
213 otg_add_timer(fsm, A_AIDL_BDIS);
216 case OTG_STATE_A_PERIPHERAL:
218 otg_set_protocol(fsm, PROTO_GADGET);
219 otg_drv_vbus(fsm, 1);
220 otg_loc_conn(fsm, 1);
221 otg_add_timer(fsm, A_BIDL_ADIS);
223 case OTG_STATE_A_WAIT_VFALL:
224 otg_drv_vbus(fsm, 0);
225 otg_loc_conn(fsm, 0);
227 otg_set_protocol(fsm, PROTO_HOST);
228 otg_add_timer(fsm, A_WAIT_VFALL);
230 case OTG_STATE_A_VBUS_ERR:
231 otg_drv_vbus(fsm, 0);
232 otg_loc_conn(fsm, 0);
234 otg_set_protocol(fsm, PROTO_UNDEF);
240 fsm->otg->state = new_state;
244 /* State change judgement */
245 int otg_statemachine(struct otg_fsm *fsm)
247 enum usb_otg_state state;
249 mutex_lock(&fsm->lock);
251 state = fsm->otg->state;
253 /* State machine state change judgement */
256 case OTG_STATE_UNDEFINED:
257 VDBG("fsm->id = %d\n", fsm->id);
259 otg_set_state(fsm, OTG_STATE_B_IDLE);
261 otg_set_state(fsm, OTG_STATE_A_IDLE);
263 case OTG_STATE_B_IDLE:
265 otg_set_state(fsm, OTG_STATE_A_IDLE);
266 else if (fsm->b_sess_vld && fsm->otg->gadget)
267 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
268 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
269 fsm->b_ssend_srp && fsm->b_se0_srp)
270 otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
272 case OTG_STATE_B_SRP_INIT:
273 if (!fsm->id || fsm->b_srp_done)
274 otg_set_state(fsm, OTG_STATE_B_IDLE);
276 case OTG_STATE_B_PERIPHERAL:
277 if (!fsm->id || !fsm->b_sess_vld)
278 otg_set_state(fsm, OTG_STATE_B_IDLE);
279 else if (fsm->b_bus_req && fsm->otg->
280 gadget->b_hnp_enable && fsm->a_bus_suspend)
281 otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
283 case OTG_STATE_B_WAIT_ACON:
285 otg_set_state(fsm, OTG_STATE_B_HOST);
286 else if (!fsm->id || !fsm->b_sess_vld)
287 otg_set_state(fsm, OTG_STATE_B_IDLE);
288 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
289 fsm->b_ase0_brst_tmout = 0;
290 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
293 case OTG_STATE_B_HOST:
294 if (!fsm->id || !fsm->b_sess_vld)
295 otg_set_state(fsm, OTG_STATE_B_IDLE);
296 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
297 otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
299 case OTG_STATE_A_IDLE:
301 otg_set_state(fsm, OTG_STATE_B_IDLE);
302 else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
303 fsm->a_srp_det || fsm->adp_change || fsm->power_up))
304 otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
306 case OTG_STATE_A_WAIT_VRISE:
308 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
309 else if (fsm->id || fsm->a_bus_drop ||
310 fsm->a_wait_vrise_tmout)
311 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
313 case OTG_STATE_A_WAIT_BCON:
314 if (!fsm->a_vbus_vld)
315 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
316 else if (fsm->b_conn)
317 otg_set_state(fsm, OTG_STATE_A_HOST);
318 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
319 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
321 case OTG_STATE_A_HOST:
322 if (fsm->id || fsm->a_bus_drop)
323 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
324 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
325 fsm->otg->host->b_hnp_enable)
326 otg_set_state(fsm, OTG_STATE_A_SUSPEND);
327 else if (!fsm->b_conn)
328 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
329 else if (!fsm->a_vbus_vld)
330 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
332 case OTG_STATE_A_SUSPEND:
333 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
334 otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
335 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
336 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
337 else if (fsm->a_bus_req || fsm->b_bus_resume)
338 otg_set_state(fsm, OTG_STATE_A_HOST);
339 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
340 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
341 else if (!fsm->a_vbus_vld)
342 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
344 case OTG_STATE_A_PERIPHERAL:
345 if (fsm->id || fsm->a_bus_drop)
346 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
347 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
348 otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
349 else if (!fsm->a_vbus_vld)
350 otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
352 case OTG_STATE_A_WAIT_VFALL:
353 if (fsm->a_wait_vfall_tmout)
354 otg_set_state(fsm, OTG_STATE_A_IDLE);
356 case OTG_STATE_A_VBUS_ERR:
357 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
358 otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
363 mutex_unlock(&fsm->lock);
365 VDBG("quit statemachine, changed = %d\n", state_changed);
366 return state_changed;
368 EXPORT_SYMBOL_GPL(otg_statemachine);
369 MODULE_LICENSE("GPL");