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 #ifdef VERBOSE
  35 #define VDBG(fmt, args...) pr_debug("[%s]  " fmt, \
  36                                  __func__, ## args)
  37 #else
  38 #define VDBG(stuff...)  do {} while (0)
  39 #endif
  40
  41 /* Change USB protocol when there is a protocol change */
  42 static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
  43 {
  44         int ret = 0;
  45
  46         if (fsm->protocol != protocol) {
  47                 VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
  48                         fsm->protocol, protocol);
  49                 /* stop old protocol */
  50                 if (fsm->protocol == PROTO_HOST)
  51                         ret = otg_start_host(fsm, 0);
  52                 else if (fsm->protocol == PROTO_GADGET)
  53                         ret = otg_start_gadget(fsm, 0);
  54                 if (ret)
  55                         return ret;
  56
  57                 /* start new protocol */
  58                 if (protocol == PROTO_HOST)
  59                         ret = otg_start_host(fsm, 1);
  60                 else if (protocol == PROTO_GADGET)
  61                         ret = otg_start_gadget(fsm, 1);
  62                 if (ret)
  63                         return ret;
  64
  65                 fsm->protocol = protocol;
  66                 return 0;
  67         }
  68
  69         return 0;
  70 }
  71
  72 /* Called when leaving a state.  Do state clean up jobs here */
  73 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
  74 {
  75         switch (old_state) {
  76         case OTG_STATE_B_IDLE:
  77                 otg_del_timer(fsm, B_SE0_SRP);
  78                 fsm->b_se0_srp = 0;
  79                 fsm->adp_sns = 0;
  80                 fsm->adp_prb = 0;
  81                 break;
  82         case OTG_STATE_B_SRP_INIT:
  83                 fsm->data_pulse = 0;
  84                 fsm->b_srp_done = 0;
  85                 break;
  86         case OTG_STATE_B_PERIPHERAL:
  87                 if (fsm->otg->gadget)
  88                         fsm->otg->gadget->host_request_flag = 0;
  89                 break;
  90         case OTG_STATE_B_WAIT_ACON:
  91                 otg_del_timer(fsm, B_ASE0_BRST);
  92                 fsm->b_ase0_brst_tmout = 0;
  93                 break;
  94         case OTG_STATE_B_HOST:
  95                 break;
  96         case OTG_STATE_A_IDLE:
  97                 fsm->adp_prb = 0;
  98                 break;
  99         case OTG_STATE_A_WAIT_VRISE:
 100                 otg_del_timer(fsm, A_WAIT_VRISE);
 101                 fsm->a_wait_vrise_tmout = 0;
 102                 break;
 103         case OTG_STATE_A_WAIT_BCON:
 104                 otg_del_timer(fsm, A_WAIT_BCON);
 105                 fsm->a_wait_bcon_tmout = 0;
 106                 break;
 107         case OTG_STATE_A_HOST:
 108                 otg_del_timer(fsm, A_WAIT_ENUM);
 109                 break;
 110         case OTG_STATE_A_SUSPEND:
 111                 otg_del_timer(fsm, A_AIDL_BDIS);
 112                 fsm->a_aidl_bdis_tmout = 0;
 113                 fsm->a_suspend_req_inf = 0;
 114                 break;
 115         case OTG_STATE_A_PERIPHERAL:
 116                 otg_del_timer(fsm, A_BIDL_ADIS);
 117                 fsm->a_bidl_adis_tmout = 0;
 118                 if (fsm->otg->gadget)
 119                         fsm->otg->gadget->host_request_flag = 0;
 120                 break;
 121         case OTG_STATE_A_WAIT_VFALL:
 122                 otg_del_timer(fsm, A_WAIT_VFALL);
 123                 fsm->a_wait_vfall_tmout = 0;
 124                 otg_del_timer(fsm, A_WAIT_VRISE);
 125                 break;
 126         case OTG_STATE_A_VBUS_ERR:
 127                 break;
 128         default:
 129                 break;
 130         }
 131 }
 132
 133 static void otg_hnp_polling_work(struct work_struct *work)
 134 {
 135         struct otg_fsm *fsm = container_of(to_delayed_work(work),
 136                                 struct otg_fsm, hnp_polling_work);
 137         struct usb_device *udev;
 138         enum usb_otg_state state = fsm->otg->state;
 139         u8 flag;
 140         int retval;
 141
 142         if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
 143                 return;
 144
 145         udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
 146         if (!udev) {
 147                 dev_err(fsm->otg->host->controller,
 148                         "no usb dev connected, can't start HNP polling\n");
 149                 return;
 150         }
 151
 152         *fsm->host_req_flag = 0;
 153         /* Get host request flag from connected USB device */
 154         retval = usb_control_msg(udev,
 155                                 usb_rcvctrlpipe(udev, 0),
 156                                 USB_REQ_GET_STATUS,
 157                                 USB_DIR_IN | USB_RECIP_DEVICE,
 158                                 0,
 159                                 OTG_STS_SELECTOR,
 160                                 fsm->host_req_flag,
 161                                 1,
 162                                 USB_CTRL_GET_TIMEOUT);
 163         if (retval != 1) {
 164                 dev_err(&udev->dev, "Get one byte OTG status failed\n");
 165                 return;
 166         }
 167
 168         flag = *fsm->host_req_flag;
 169         if (flag == 0) {
 170                 /* Continue HNP polling */
 171                 schedule_delayed_work(&fsm->hnp_polling_work,
 172                                         msecs_to_jiffies(T_HOST_REQ_POLL));
 173                 return;
 174         } else if (flag != HOST_REQUEST_FLAG) {
 175                 dev_err(&udev->dev, "host request flag %d is invalid\n", flag);
 176                 return;
 177         }
 178
 179         /* Host request flag is set */
 180         if (state == OTG_STATE_A_HOST) {
 181                 /* Set b_hnp_enable */
 182                 if (!fsm->otg->host->b_hnp_enable) {
 183                         retval = usb_control_msg(udev,
 184                                         usb_sndctrlpipe(udev, 0),
 185                                         USB_REQ_SET_FEATURE, 0,
 186                                         USB_DEVICE_B_HNP_ENABLE,
 187                                         0, NULL, 0,
 188                                         USB_CTRL_SET_TIMEOUT);
 189                         if (retval >= 0)
 190                                 fsm->otg->host->b_hnp_enable = 1;
 191                 }
 192                 fsm->a_bus_req = 0;
 193         } else if (state == OTG_STATE_B_HOST) {
 194                 fsm->b_bus_req = 0;
 195         }
 196
 197         otg_statemachine(fsm);
 198 }
 199
 200 static void otg_start_hnp_polling(struct otg_fsm *fsm)
 201 {
 202         /*
 203          * The memory of host_req_flag should be allocated by
 204          * controller driver, otherwise, hnp polling is not started.
 205          */
 206         if (!fsm->host_req_flag)
 207                 return;
 208
 209         if (!fsm->hnp_work_inited) {
 210                 INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
 211                 fsm->hnp_work_inited = true;
 212         }
 213
 214         schedule_delayed_work(&fsm->hnp_polling_work,
 215                                         msecs_to_jiffies(T_HOST_REQ_POLL));
 216 }
 217
 218 /* Called when entering a state */
 219 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 220 {
 221         if (fsm->otg->state == new_state)
 222                 return 0;
 223         VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 224         otg_leave_state(fsm, fsm->otg->state);
 225         switch (new_state) {
 226         case OTG_STATE_B_IDLE:
 227                 otg_drv_vbus(fsm, 0);
 228                 otg_chrg_vbus(fsm, 0);
 229                 otg_loc_conn(fsm, 0);
 230                 otg_loc_sof(fsm, 0);
 231                 /*
 232                  * Driver is responsible for starting ADP probing
 233                  * if ADP sensing times out.
 234                  */
 235                 otg_start_adp_sns(fsm);
 236                 otg_set_protocol(fsm, PROTO_UNDEF);
 237                 otg_add_timer(fsm, B_SE0_SRP);
 238                 break;
 239         case OTG_STATE_B_SRP_INIT:
 240                 otg_start_pulse(fsm);
 241                 otg_loc_sof(fsm, 0);
 242                 otg_set_protocol(fsm, PROTO_UNDEF);
 243                 otg_add_timer(fsm, B_SRP_FAIL);
 244                 break;
 245         case OTG_STATE_B_PERIPHERAL:
 246                 otg_chrg_vbus(fsm, 0);
 247                 otg_loc_sof(fsm, 0);
 248                 otg_set_protocol(fsm, PROTO_GADGET);
 249                 otg_loc_conn(fsm, 1);
 250                 break;
 251         case OTG_STATE_B_WAIT_ACON:
 252                 otg_chrg_vbus(fsm, 0);
 253                 otg_loc_conn(fsm, 0);
 254                 otg_loc_sof(fsm, 0);
 255                 otg_set_protocol(fsm, PROTO_HOST);
 256                 otg_add_timer(fsm, B_ASE0_BRST);
 257                 fsm->a_bus_suspend = 0;
 258                 break;
 259         case OTG_STATE_B_HOST:
 260                 otg_chrg_vbus(fsm, 0);
 261                 otg_loc_conn(fsm, 0);
 262                 otg_loc_sof(fsm, 1);
 263                 otg_set_protocol(fsm, PROTO_HOST);
 264                 usb_bus_start_enum(fsm->otg->host,
 265                                 fsm->otg->host->otg_port);
 266                 otg_start_hnp_polling(fsm);
 267                 break;
 268         case OTG_STATE_A_IDLE:
 269                 otg_drv_vbus(fsm, 0);
 270                 otg_chrg_vbus(fsm, 0);
 271                 otg_loc_conn(fsm, 0);
 272                 otg_loc_sof(fsm, 0);
 273                 otg_start_adp_prb(fsm);
 274                 otg_set_protocol(fsm, PROTO_HOST);
 275                 break;
 276         case OTG_STATE_A_WAIT_VRISE:
 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_VRISE);
 282                 break;
 283         case OTG_STATE_A_WAIT_BCON:
 284                 otg_drv_vbus(fsm, 1);
 285                 otg_loc_conn(fsm, 0);
 286                 otg_loc_sof(fsm, 0);
 287                 otg_set_protocol(fsm, PROTO_HOST);
 288                 otg_add_timer(fsm, A_WAIT_BCON);
 289                 break;
 290         case OTG_STATE_A_HOST:
 291                 otg_drv_vbus(fsm, 1);
 292                 otg_loc_conn(fsm, 0);
 293                 otg_loc_sof(fsm, 1);
 294                 otg_set_protocol(fsm, PROTO_HOST);
 295                 /*
 296                  * When HNP is triggered while a_bus_req = 0, a_host will
 297                  * suspend too fast to complete a_set_b_hnp_en
 298                  */
 299                 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
 300                         otg_add_timer(fsm, A_WAIT_ENUM);
 301                 otg_start_hnp_polling(fsm);
 302                 break;
 303         case OTG_STATE_A_SUSPEND:
 304                 otg_drv_vbus(fsm, 1);
 305                 otg_loc_conn(fsm, 0);
 306                 otg_loc_sof(fsm, 0);
 307                 otg_set_protocol(fsm, PROTO_HOST);
 308                 otg_add_timer(fsm, A_AIDL_BDIS);
 309
 310                 break;
 311         case OTG_STATE_A_PERIPHERAL:
 312                 otg_loc_sof(fsm, 0);
 313                 otg_set_protocol(fsm, PROTO_GADGET);
 314                 otg_drv_vbus(fsm, 1);
 315                 otg_loc_conn(fsm, 1);
 316                 otg_add_timer(fsm, A_BIDL_ADIS);
 317                 break;
 318         case OTG_STATE_A_WAIT_VFALL:
 319                 otg_drv_vbus(fsm, 0);
 320                 otg_loc_conn(fsm, 0);
 321                 otg_loc_sof(fsm, 0);
 322                 otg_set_protocol(fsm, PROTO_HOST);
 323                 otg_add_timer(fsm, A_WAIT_VFALL);
 324                 break;
 325         case OTG_STATE_A_VBUS_ERR:
 326                 otg_drv_vbus(fsm, 0);
 327                 otg_loc_conn(fsm, 0);
 328                 otg_loc_sof(fsm, 0);
 329                 otg_set_protocol(fsm, PROTO_UNDEF);
 330                 break;
 331         default:
 332                 break;
 333         }
 334
 335         fsm->otg->state = new_state;
 336         fsm->state_changed = 1;
 337         return 0;
 338 }
 339
 340 /* State change judgement */
 341 int otg_statemachine(struct otg_fsm *fsm)
 342 {
 343         enum usb_otg_state state;
 344
 345         mutex_lock(&fsm->lock);
 346
 347         state = fsm->otg->state;
 348         fsm->state_changed = 0;
 349         /* State machine state change judgement */
 350
 351         switch (state) {
 352         case OTG_STATE_UNDEFINED:
 353                 VDBG("fsm->id = %d\n", fsm->id);
 354                 if (fsm->id)
 355                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 356                 else
 357                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 358                 break;
 359         case OTG_STATE_B_IDLE:
 360                 if (!fsm->id)
 361                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 362                 else if (fsm->b_sess_vld && fsm->otg->gadget)
 363                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 364                 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
 365                                 fsm->b_ssend_srp && fsm->b_se0_srp)
 366                         otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 367                 break;
 368         case OTG_STATE_B_SRP_INIT:
 369                 if (!fsm->id || fsm->b_srp_done)
 370                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 371                 break;
 372         case OTG_STATE_B_PERIPHERAL:
 373                 if (!fsm->id || !fsm->b_sess_vld)
 374                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 375                 else if (fsm->b_bus_req && fsm->otg->
 376                                 gadget->b_hnp_enable && fsm->a_bus_suspend)
 377                         otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 378                 break;
 379         case OTG_STATE_B_WAIT_ACON:
 380                 if (fsm->a_conn)
 381                         otg_set_state(fsm, OTG_STATE_B_HOST);
 382                 else if (!fsm->id || !fsm->b_sess_vld)
 383                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 384                 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 385                         fsm->b_ase0_brst_tmout = 0;
 386                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 387                 }
 388                 break;
 389         case OTG_STATE_B_HOST:
 390                 if (!fsm->id || !fsm->b_sess_vld)
 391                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 392                 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
 393                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 394                 break;
 395         case OTG_STATE_A_IDLE:
 396                 if (fsm->id)
 397                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 398                 else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
 399                           fsm->a_srp_det || fsm->adp_change || fsm->power_up))
 400                         otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 401                 break;
 402         case OTG_STATE_A_WAIT_VRISE:
 403                 if (fsm->a_vbus_vld)
 404                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 405                 else if (fsm->id || fsm->a_bus_drop ||
 406                                 fsm->a_wait_vrise_tmout)
 407                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 408                 break;
 409         case OTG_STATE_A_WAIT_BCON:
 410                 if (!fsm->a_vbus_vld)
 411                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 412                 else if (fsm->b_conn)
 413                         otg_set_state(fsm, OTG_STATE_A_HOST);
 414                 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
 415                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 416                 break;
 417         case OTG_STATE_A_HOST:
 418                 if (fsm->id || fsm->a_bus_drop)
 419                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 420                 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
 421                                 fsm->otg->host->b_hnp_enable)
 422                         otg_set_state(fsm, OTG_STATE_A_SUSPEND);
 423                 else if (!fsm->b_conn)
 424                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 425                 else if (!fsm->a_vbus_vld)
 426                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 427                 break;
 428         case OTG_STATE_A_SUSPEND:
 429                 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
 430                         otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 431                 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
 432                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 433                 else if (fsm->a_bus_req || fsm->b_bus_resume)
 434                         otg_set_state(fsm, OTG_STATE_A_HOST);
 435                 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 436                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 437                 else if (!fsm->a_vbus_vld)
 438                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 439                 break;
 440         case OTG_STATE_A_PERIPHERAL:
 441                 if (fsm->id || fsm->a_bus_drop)
 442                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 443                 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
 444                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 445                 else if (!fsm->a_vbus_vld)
 446                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 447                 break;
 448         case OTG_STATE_A_WAIT_VFALL:
 449                 if (fsm->a_wait_vfall_tmout)
 450                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 451                 break;
 452         case OTG_STATE_A_VBUS_ERR:
 453                 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 454                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 455                 break;
 456         default:
 457                 break;
 458         }
 459         mutex_unlock(&fsm->lock);
 460
 461         VDBG("quit statemachine, changed = %d\n", fsm->state_changed);
 462         return fsm->state_changed;
 463 }
 464 EXPORT_SYMBOL_GPL(otg_statemachine);
 465 MODULE_LICENSE("GPL");