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

   1 /*
   2  * OTG Finite State Machine from OTG spec
   3  *
   4  * Copyright (C) 2007-2015 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 /* Called when entering a state */
 128 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 129 {
 130         state_changed = 1;
 131         if (fsm->otg->state == new_state)
 132                 return 0;
 133         VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 134         otg_leave_state(fsm, fsm->otg->state);
 135         switch (new_state) {
 136         case OTG_STATE_B_IDLE:
 137                 otg_drv_vbus(fsm, 0);
 138                 otg_chrg_vbus(fsm, 0);
 139                 otg_loc_conn(fsm, 0);
 140                 otg_loc_sof(fsm, 0);
 141                 /*
 142                  * Driver is responsible for starting ADP probing
 143                  * if ADP sensing times out.
 144                  */
 145                 otg_start_adp_sns(fsm);
 146                 otg_set_protocol(fsm, PROTO_UNDEF);
 147                 otg_add_timer(fsm, B_SE0_SRP);
 148                 break;
 149         case OTG_STATE_B_SRP_INIT:
 150                 otg_start_pulse(fsm);
 151                 otg_loc_sof(fsm, 0);
 152                 otg_set_protocol(fsm, PROTO_UNDEF);
 153                 otg_add_timer(fsm, B_SRP_FAIL);
 154                 break;
 155         case OTG_STATE_B_PERIPHERAL:
 156                 otg_chrg_vbus(fsm, 0);
 157                 otg_loc_conn(fsm, 1);
 158                 otg_loc_sof(fsm, 0);
 159                 otg_set_protocol(fsm, PROTO_GADGET);
 160                 break;
 161         case OTG_STATE_B_WAIT_ACON:
 162                 otg_chrg_vbus(fsm, 0);
 163                 otg_loc_conn(fsm, 0);
 164                 otg_loc_sof(fsm, 0);
 165                 otg_set_protocol(fsm, PROTO_HOST);
 166                 otg_add_timer(fsm, B_ASE0_BRST);
 167                 fsm->a_bus_suspend = 0;
 168                 break;
 169         case OTG_STATE_B_HOST:
 170                 otg_chrg_vbus(fsm, 0);
 171                 otg_loc_conn(fsm, 0);
 172                 otg_loc_sof(fsm, 1);
 173                 otg_set_protocol(fsm, PROTO_HOST);
 174                 usb_bus_start_enum(fsm->otg->host,
 175                                 fsm->otg->host->otg_port);
 176                 otg_add_timer(fsm, HNP_POLLING);
 177                 break;
 178         case OTG_STATE_A_IDLE:
 179                 otg_drv_vbus(fsm, 0);
 180                 otg_chrg_vbus(fsm, 0);
 181                 otg_loc_conn(fsm, 0);
 182                 otg_loc_sof(fsm, 0);
 183                 otg_start_adp_prb(fsm);
 184                 otg_set_protocol(fsm, PROTO_HOST);
 185                 break;
 186         case OTG_STATE_A_WAIT_VRISE:
 187                 otg_drv_vbus(fsm, 1);
 188                 otg_loc_conn(fsm, 0);
 189                 otg_loc_sof(fsm, 0);
 190                 otg_set_protocol(fsm, PROTO_HOST);
 191                 otg_add_timer(fsm, A_WAIT_VRISE);
 192                 break;
 193         case OTG_STATE_A_WAIT_BCON:
 194                 otg_drv_vbus(fsm, 1);
 195                 otg_loc_conn(fsm, 0);
 196                 otg_loc_sof(fsm, 0);
 197                 otg_set_protocol(fsm, PROTO_HOST);
 198                 otg_add_timer(fsm, A_WAIT_BCON);
 199                 break;
 200         case OTG_STATE_A_HOST:
 201                 otg_drv_vbus(fsm, 1);
 202                 otg_loc_conn(fsm, 0);
 203                 otg_loc_sof(fsm, 1);
 204                 otg_set_protocol(fsm, PROTO_HOST);
 205                 /*
 206                  * When HNP is triggered while a_bus_req = 0, a_host will
 207                  * suspend too fast to complete a_set_b_hnp_en
 208                  */
 209                 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
 210                         otg_add_timer(fsm, A_WAIT_ENUM);
 211                 otg_add_timer(fsm, HNP_POLLING);
 212                 break;
 213         case OTG_STATE_A_SUSPEND:
 214                 otg_drv_vbus(fsm, 1);
 215                 otg_loc_conn(fsm, 0);
 216                 otg_loc_sof(fsm, 0);
 217                 otg_set_protocol(fsm, PROTO_HOST);
 218                 otg_add_timer(fsm, A_AIDL_BDIS);
 219
 220                 break;
 221         case OTG_STATE_A_PERIPHERAL:
 222                 otg_loc_conn(fsm, 1);
 223                 otg_loc_sof(fsm, 0);
 224                 otg_set_protocol(fsm, PROTO_GADGET);
 225                 otg_drv_vbus(fsm, 1);
 226                 otg_add_timer(fsm, A_BIDL_ADIS);
 227                 break;
 228         case OTG_STATE_A_WAIT_VFALL:
 229                 otg_drv_vbus(fsm, 0);
 230                 otg_loc_conn(fsm, 0);
 231                 otg_loc_sof(fsm, 0);
 232                 otg_set_protocol(fsm, PROTO_HOST);
 233                 otg_add_timer(fsm, A_WAIT_VFALL);
 234                 break;
 235         case OTG_STATE_A_VBUS_ERR:
 236                 otg_drv_vbus(fsm, 0);
 237                 otg_loc_conn(fsm, 0);
 238                 otg_loc_sof(fsm, 0);
 239                 otg_set_protocol(fsm, PROTO_UNDEF);
 240                 break;
 241         default:
 242                 break;
 243         }
 244
 245         fsm->otg->state = new_state;
 246         return 0;
 247 }
 248
 249 /* State change judgement */
 250 int otg_statemachine(struct otg_fsm *fsm)
 251 {
 252         enum usb_otg_state state;
 253
 254         mutex_lock(&fsm->lock);
 255
 256         state = fsm->otg->state;
 257         state_changed = 0;
 258         /* State machine state change judgement */
 259
 260         switch (state) {
 261         case OTG_STATE_UNDEFINED:
 262                 VDBG("fsm->id = %d\n", fsm->id);
 263                 if (fsm->id)
 264                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 265                 else
 266                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 267                 break;
 268         case OTG_STATE_B_IDLE:
 269                 if (!fsm->id)
 270                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 271                 else if (fsm->b_sess_vld && fsm->otg->gadget)
 272                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 273                 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
 274                                 fsm->b_ssend_srp && fsm->b_se0_srp)
 275                         otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 276                 break;
 277         case OTG_STATE_B_SRP_INIT:
 278                 if (!fsm->id || fsm->b_srp_done)
 279                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 280                 break;
 281         case OTG_STATE_B_PERIPHERAL:
 282                 if (!fsm->id || !fsm->b_sess_vld)
 283                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 284                 else if (fsm->b_bus_req && fsm->otg->
 285                                 gadget->b_hnp_enable && fsm->a_bus_suspend)
 286                         otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 287                 break;
 288         case OTG_STATE_B_WAIT_ACON:
 289                 if (fsm->a_conn)
 290                         otg_set_state(fsm, OTG_STATE_B_HOST);
 291                 else if (!fsm->id || !fsm->b_sess_vld)
 292                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 293                 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 294                         fsm->b_ase0_brst_tmout = 0;
 295                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 296                 }
 297                 break;
 298         case OTG_STATE_B_HOST:
 299                 if (!fsm->id || !fsm->b_sess_vld)
 300                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 301                 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
 302                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 303                 break;
 304         case OTG_STATE_A_IDLE:
 305                 if (fsm->id)
 306                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 307                 else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
 308                           fsm->a_srp_det || fsm->adp_change || fsm->power_up))
 309                         otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 310                 break;
 311         case OTG_STATE_A_WAIT_VRISE:
 312                 if (fsm->a_vbus_vld)
 313                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 314                 else if (fsm->id || fsm->a_bus_drop ||
 315                                 fsm->a_wait_vrise_tmout)
 316                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 317                 break;
 318         case OTG_STATE_A_WAIT_BCON:
 319                 if (!fsm->a_vbus_vld)
 320                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 321                 else if (fsm->b_conn)
 322                         otg_set_state(fsm, OTG_STATE_A_HOST);
 323                 else if (fsm->id | fsm->a_bus_drop | fsm->a_wait_bcon_tmout)
 324                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 325                 break;
 326         case OTG_STATE_A_HOST:
 327                 if (fsm->id || fsm->a_bus_drop)
 328                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 329                 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
 330                                 fsm->otg->host->b_hnp_enable)
 331                         otg_set_state(fsm, OTG_STATE_A_SUSPEND);
 332                 else if (!fsm->b_conn)
 333                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 334                 else if (!fsm->a_vbus_vld)
 335                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 336                 break;
 337         case OTG_STATE_A_SUSPEND:
 338                 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
 339                         otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 340                 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
 341                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 342                 else if (fsm->a_bus_req || fsm->b_bus_resume)
 343                         otg_set_state(fsm, OTG_STATE_A_HOST);
 344                 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 345                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 346                 else if (!fsm->a_vbus_vld)
 347                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 348                 break;
 349         case OTG_STATE_A_PERIPHERAL:
 350                 if (fsm->id || fsm->a_bus_drop)
 351                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 352                 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
 353                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 354                 else if (!fsm->a_vbus_vld)
 355                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 356                 break;
 357         case OTG_STATE_A_WAIT_VFALL:
 358                 if (fsm->a_wait_vfall_tmout)
 359                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 360                 break;
 361         case OTG_STATE_A_VBUS_ERR:
 362                 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 363                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 364                 break;
 365         default:
 366                 break;
 367         }
 368         mutex_unlock(&fsm->lock);
 369
 370         VDBG("quit statemachine, changed = %d\n", state_changed);
 371         return state_changed;
 372 }
 373 EXPORT_SYMBOL_GPL(otg_statemachine);
 374
 375 static int otg_handle_role_switch(struct otg_fsm *fsm, struct usb_device *udev)
 376 {
 377         int err;
 378         enum usb_otg_state state = fsm->otg->state;
 379
 380         if (state == OTG_STATE_A_HOST) {
 381                 /* Set b_hnp_enable */
 382                 if (!fsm->a_set_b_hnp_en) {
 383                         err = usb_control_msg(udev,
 384                                 usb_sndctrlpipe(udev, 0),
 385                                 USB_REQ_SET_FEATURE, 0,
 386                                 USB_DEVICE_B_HNP_ENABLE,
 387                                 0, NULL, 0,
 388                                 USB_CTRL_SET_TIMEOUT);
 389                         if (err < 0) {
 390                                 /* Continue polling */
 391                                 otg_add_timer(fsm, HNP_POLLING);
 392                                 return 0;
 393                         } else {
 394                                 fsm->a_set_b_hnp_en = 1;
 395                         }
 396                 }
 397                 fsm->a_bus_req = 0;
 398                 return HOST_REQUEST_FLAG;
 399         } else if (state == OTG_STATE_B_HOST) {
 400                 fsm->b_bus_req = 0;
 401                 return HOST_REQUEST_FLAG;
 402         }
 403
 404         return -EINVAL;
 405 }
 406
 407 /*
 408  * Called by host to poll peripheral if it wants to be host
 409  * Return value:
 410  * - host request flag(1) if the device wants to be host,
 411  * - host request flag(0) if the device keeps peripheral role,
 412  * - otherwise, error code.
 413  */
 414 int otg_hnp_polling(struct otg_fsm *fsm)
 415 {
 416         struct usb_device *udev;
 417         u8 host_req_flag;
 418         int retval;
 419         enum usb_otg_state state = fsm->otg->state;
 420
 421         if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
 422                 return -EINVAL;
 423
 424         udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
 425         if (!udev) {
 426                 dev_err(fsm->otg->host->controller,
 427                         "no usb dev connected, can't start HNP polling\n");
 428                 return -ENODEV;
 429         }
 430
 431         /* Get host request flag from connected USB device */
 432         retval = usb_control_msg(udev,
 433                                 usb_rcvctrlpipe(udev, 0),
 434                                 USB_REQ_GET_STATUS,
 435                                 USB_DIR_IN | USB_RECIP_DEVICE,
 436                                 0,
 437                                 OTG_STS_SELECTOR,
 438                                 &host_req_flag,
 439                                 1,
 440                                 USB_CTRL_GET_TIMEOUT);
 441         if (retval == 1) {
 442                 if (host_req_flag == HOST_REQUEST_FLAG) {
 443                         retval = otg_handle_role_switch(fsm, udev);
 444                 } else if (host_req_flag == 0) {
 445                         /* Continue polling */
 446                         otg_add_timer(fsm, HNP_POLLING);
 447                         retval = 0;
 448                 } else {
 449                         dev_err(&udev->dev, "host request flag is invalid\n");
 450                         retval = -EINVAL;
 451                 }
 452         } else {
 453                 dev_err(&udev->dev, "Get one byte OTG status failed\n");
 454                 retval = -EIO;
 455         }
 456         return retval;
 457 }
 458 EXPORT_SYMBOL_GPL(otg_hnp_polling);