drivers/usb/common/usb-otg-fsm.c

   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 */
  35 static 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 */
  66 static 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
 126 static 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
 193 static 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         if (!fsm->hnp_work_inited) {
 203                 INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
 204                 fsm->hnp_work_inited = true;
 205         }
 206
 207         schedule_delayed_work(&fsm->hnp_polling_work,
 208                                         msecs_to_jiffies(T_HOST_REQ_POLL));
 209 }
 210
 211 /* Called when entering a state */
 212 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 213 {
 214         if (fsm->otg->state == new_state)
 215                 return 0;
 216         VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 217         otg_leave_state(fsm, fsm->otg->state);
 218         switch (new_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);
 223                 otg_loc_sof(fsm, 0);
 224                 /*
 225                  * Driver is responsible for starting ADP probing
 226                  * if ADP sensing times out.
 227                  */
 228                 otg_start_adp_sns(fsm);
 229                 otg_set_protocol(fsm, PROTO_UNDEF);
 230                 otg_add_timer(fsm, B_SE0_SRP);
 231                 break;
 232         case OTG_STATE_B_SRP_INIT:
 233                 otg_start_pulse(fsm);
 234                 otg_loc_sof(fsm, 0);
 235                 otg_set_protocol(fsm, PROTO_UNDEF);
 236                 otg_add_timer(fsm, B_SRP_FAIL);
 237                 break;
 238         case OTG_STATE_B_PERIPHERAL:
 239                 otg_chrg_vbus(fsm, 0);
 240                 otg_loc_sof(fsm, 0);
 241                 otg_set_protocol(fsm, PROTO_GADGET);
 242                 otg_loc_conn(fsm, 1);
 243                 break;
 244         case OTG_STATE_B_WAIT_ACON:
 245                 otg_chrg_vbus(fsm, 0);
 246                 otg_loc_conn(fsm, 0);
 247                 otg_loc_sof(fsm, 0);
 248                 otg_set_protocol(fsm, PROTO_HOST);
 249                 otg_add_timer(fsm, B_ASE0_BRST);
 250                 fsm->a_bus_suspend = 0;
 251                 break;
 252         case OTG_STATE_B_HOST:
 253                 otg_chrg_vbus(fsm, 0);
 254                 otg_loc_conn(fsm, 0);
 255                 otg_loc_sof(fsm, 1);
 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);
 260                 break;
 261         case OTG_STATE_A_IDLE:
 262                 otg_drv_vbus(fsm, 0);
 263                 otg_chrg_vbus(fsm, 0);
 264                 otg_loc_conn(fsm, 0);
 265                 otg_loc_sof(fsm, 0);
 266                 otg_start_adp_prb(fsm);
 267                 otg_set_protocol(fsm, PROTO_HOST);
 268                 break;
 269         case OTG_STATE_A_WAIT_VRISE:
 270                 otg_drv_vbus(fsm, 1);
 271                 otg_loc_conn(fsm, 0);
 272                 otg_loc_sof(fsm, 0);
 273                 otg_set_protocol(fsm, PROTO_HOST);
 274                 otg_add_timer(fsm, A_WAIT_VRISE);
 275                 break;
 276         case OTG_STATE_A_WAIT_BCON:
 277                 otg_drv_vbus(fsm, 1);
 278                 otg_loc_conn(fsm, 0);
 279                 otg_loc_sof(fsm, 0);
 280                 otg_set_protocol(fsm, PROTO_HOST);
 281                 otg_add_timer(fsm, A_WAIT_BCON);
 282                 break;
 283         case OTG_STATE_A_HOST:
 284                 otg_drv_vbus(fsm, 1);
 285                 otg_loc_conn(fsm, 0);
 286                 otg_loc_sof(fsm, 1);
 287                 otg_set_protocol(fsm, PROTO_HOST);
 288                 /*
 289                  * When HNP is triggered while a_bus_req = 0, a_host will
 290                  * suspend too fast to complete a_set_b_hnp_en
 291                  */
 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);
 295                 break;
 296         case OTG_STATE_A_SUSPEND:
 297                 otg_drv_vbus(fsm, 1);
 298                 otg_loc_conn(fsm, 0);
 299                 otg_loc_sof(fsm, 0);
 300                 otg_set_protocol(fsm, PROTO_HOST);
 301                 otg_add_timer(fsm, A_AIDL_BDIS);
 302
 303                 break;
 304         case OTG_STATE_A_PERIPHERAL:
 305                 otg_loc_sof(fsm, 0);
 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);
 310                 break;
 311         case OTG_STATE_A_WAIT_VFALL:
 312                 otg_drv_vbus(fsm, 0);
 313                 otg_loc_conn(fsm, 0);
 314                 otg_loc_sof(fsm, 0);
 315                 otg_set_protocol(fsm, PROTO_HOST);
 316                 otg_add_timer(fsm, A_WAIT_VFALL);
 317                 break;
 318         case OTG_STATE_A_VBUS_ERR:
 319                 otg_drv_vbus(fsm, 0);
 320                 otg_loc_conn(fsm, 0);
 321                 otg_loc_sof(fsm, 0);
 322                 otg_set_protocol(fsm, PROTO_UNDEF);
 323                 break;
 324         default:
 325                 break;
 326         }
 327
 328         fsm->otg->state = new_state;
 329         fsm->state_changed = 1;
 330         return 0;
 331 }
 332
 333 /* State change judgement */
 334 int otg_statemachine(struct otg_fsm *fsm)
 335 {
 336         enum usb_otg_state state;
 337
 338         mutex_lock(&fsm->lock);
 339
 340         state = fsm->otg->state;
 341         fsm->state_changed = 0;
 342         /* State machine state change judgement */
 343
 344         switch (state) {
 345         case OTG_STATE_UNDEFINED:
 346                 VDBG("fsm->id = %d\n", fsm->id);
 347                 if (fsm->id)
 348                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 349                 else
 350                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 351                 break;
 352         case OTG_STATE_B_IDLE:
 353                 if (!fsm->id)
 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);
 360                 break;
 361         case OTG_STATE_B_SRP_INIT:
 362                 if (!fsm->id || fsm->b_srp_done)
 363                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 364                 break;
 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);
 371                 break;
 372         case OTG_STATE_B_WAIT_ACON:
 373                 if (fsm->a_conn)
 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);
 380                 }
 381                 break;
 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);
 387                 break;
 388         case OTG_STATE_A_IDLE:
 389                 if (fsm->id)
 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);
 394                 break;
 395         case OTG_STATE_A_WAIT_VRISE:
 396                 if (fsm->a_vbus_vld)
 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);
 401                 break;
 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);
 409                 break;
 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);
 420                 break;
 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);
 432                 break;
 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);
 440                 break;
 441         case OTG_STATE_A_WAIT_VFALL:
 442                 if (fsm->a_wait_vfall_tmout)
 443                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 444                 break;
 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);
 448                 break;
 449         default:
 450                 break;
 451         }
 452         mutex_unlock(&fsm->lock);
 453
 454         VDBG("quit statemachine, changed = %d\n", fsm->state_changed);
 455         return fsm->state_changed;
 456 }
 457 EXPORT_SYMBOL_GPL(otg_statemachine);
 458 MODULE_LICENSE("GPL");