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