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