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                 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                 break;
 111         case OTG_STATE_A_WAIT_VFALL:
 112                 otg_del_timer(fsm, A_WAIT_VFALL);
 113                 fsm->a_wait_vfall_tmout = 0;
 114                 otg_del_timer(fsm, A_WAIT_VRISE);
 115                 break;
 116         case OTG_STATE_A_VBUS_ERR:
 117                 break;
 118         default:
 119                 break;
 120         }
 121 }
 122
 123 /* Called when entering a state */
 124 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 125 {
 126         state_changed = 1;
 127         if (fsm->otg->state == new_state)
 128                 return 0;
 129         VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 130         otg_leave_state(fsm, fsm->otg->state);
 131         switch (new_state) {
 132         case OTG_STATE_B_IDLE:
 133                 otg_drv_vbus(fsm, 0);
 134                 otg_chrg_vbus(fsm, 0);
 135                 otg_loc_conn(fsm, 0);
 136                 otg_loc_sof(fsm, 0);
 137                 /*
 138                  * Driver is responsible for starting ADP probing
 139                  * if ADP sensing times out.
 140                  */
 141                 otg_start_adp_sns(fsm);
 142                 otg_set_protocol(fsm, PROTO_UNDEF);
 143                 otg_add_timer(fsm, B_SE0_SRP);
 144                 break;
 145         case OTG_STATE_B_SRP_INIT:
 146                 otg_start_pulse(fsm);
 147                 otg_loc_sof(fsm, 0);
 148                 otg_set_protocol(fsm, PROTO_UNDEF);
 149                 otg_add_timer(fsm, B_SRP_FAIL);
 150                 break;
 151         case OTG_STATE_B_PERIPHERAL:
 152                 otg_chrg_vbus(fsm, 0);
 153                 otg_loc_sof(fsm, 0);
 154                 otg_set_protocol(fsm, PROTO_GADGET);
 155                 otg_loc_conn(fsm, 1);
 156                 break;
 157         case OTG_STATE_B_WAIT_ACON:
 158                 otg_chrg_vbus(fsm, 0);
 159                 otg_loc_conn(fsm, 0);
 160                 otg_loc_sof(fsm, 0);
 161                 otg_set_protocol(fsm, PROTO_HOST);
 162                 otg_add_timer(fsm, B_ASE0_BRST);
 163                 fsm->a_bus_suspend = 0;
 164                 break;
 165         case OTG_STATE_B_HOST:
 166                 otg_chrg_vbus(fsm, 0);
 167                 otg_loc_conn(fsm, 0);
 168                 otg_loc_sof(fsm, 1);
 169                 otg_set_protocol(fsm, PROTO_HOST);
 170                 usb_bus_start_enum(fsm->otg->host,
 171                                 fsm->otg->host->otg_port);
 172                 break;
 173         case OTG_STATE_A_IDLE:
 174                 otg_drv_vbus(fsm, 0);
 175                 otg_chrg_vbus(fsm, 0);
 176                 otg_loc_conn(fsm, 0);
 177                 otg_loc_sof(fsm, 0);
 178                 otg_start_adp_prb(fsm);
 179                 otg_set_protocol(fsm, PROTO_HOST);
 180                 break;
 181         case OTG_STATE_A_WAIT_VRISE:
 182                 otg_drv_vbus(fsm, 1);
 183                 otg_loc_conn(fsm, 0);
 184                 otg_loc_sof(fsm, 0);
 185                 otg_set_protocol(fsm, PROTO_HOST);
 186                 otg_add_timer(fsm, A_WAIT_VRISE);
 187                 break;
 188         case OTG_STATE_A_WAIT_BCON:
 189                 otg_drv_vbus(fsm, 1);
 190                 otg_loc_conn(fsm, 0);
 191                 otg_loc_sof(fsm, 0);
 192                 otg_set_protocol(fsm, PROTO_HOST);
 193                 otg_add_timer(fsm, A_WAIT_BCON);
 194                 break;
 195         case OTG_STATE_A_HOST:
 196                 otg_drv_vbus(fsm, 1);
 197                 otg_loc_conn(fsm, 0);
 198                 otg_loc_sof(fsm, 1);
 199                 otg_set_protocol(fsm, PROTO_HOST);
 200                 /*
 201                  * When HNP is triggered while a_bus_req = 0, a_host will
 202                  * suspend too fast to complete a_set_b_hnp_en
 203                  */
 204                 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
 205                         otg_add_timer(fsm, A_WAIT_ENUM);
 206                 break;
 207         case OTG_STATE_A_SUSPEND:
 208                 otg_drv_vbus(fsm, 1);
 209                 otg_loc_conn(fsm, 0);
 210                 otg_loc_sof(fsm, 0);
 211                 otg_set_protocol(fsm, PROTO_HOST);
 212                 otg_add_timer(fsm, A_AIDL_BDIS);
 213
 214                 break;
 215         case OTG_STATE_A_PERIPHERAL:
 216                 otg_loc_sof(fsm, 0);
 217                 otg_set_protocol(fsm, PROTO_GADGET);
 218                 otg_drv_vbus(fsm, 1);
 219                 otg_loc_conn(fsm, 1);
 220                 otg_add_timer(fsm, A_BIDL_ADIS);
 221                 break;
 222         case OTG_STATE_A_WAIT_VFALL:
 223                 otg_drv_vbus(fsm, 0);
 224                 otg_loc_conn(fsm, 0);
 225                 otg_loc_sof(fsm, 0);
 226                 otg_set_protocol(fsm, PROTO_HOST);
 227                 otg_add_timer(fsm, A_WAIT_VFALL);
 228                 break;
 229         case OTG_STATE_A_VBUS_ERR:
 230                 otg_drv_vbus(fsm, 0);
 231                 otg_loc_conn(fsm, 0);
 232                 otg_loc_sof(fsm, 0);
 233                 otg_set_protocol(fsm, PROTO_UNDEF);
 234                 break;
 235         default:
 236                 break;
 237         }
 238
 239         fsm->otg->state = new_state;
 240         return 0;
 241 }
 242
 243 /* State change judgement */
 244 int otg_statemachine(struct otg_fsm *fsm)
 245 {
 246         enum usb_otg_state state;
 247
 248         mutex_lock(&fsm->lock);
 249
 250         state = fsm->otg->state;
 251         state_changed = 0;
 252         /* State machine state change judgement */
 253
 254         switch (state) {
 255         case OTG_STATE_UNDEFINED:
 256                 VDBG("fsm->id = %d\n", fsm->id);
 257                 if (fsm->id)
 258                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 259                 else
 260                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 261                 break;
 262         case OTG_STATE_B_IDLE:
 263                 if (!fsm->id)
 264                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 265                 else if (fsm->b_sess_vld && fsm->otg->gadget)
 266                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 267                 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
 268                                 fsm->b_ssend_srp && fsm->b_se0_srp)
 269                         otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 270                 break;
 271         case OTG_STATE_B_SRP_INIT:
 272                 if (!fsm->id || fsm->b_srp_done)
 273                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 274                 break;
 275         case OTG_STATE_B_PERIPHERAL:
 276                 if (!fsm->id || !fsm->b_sess_vld)
 277                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 278                 else if (fsm->b_bus_req && fsm->otg->
 279                                 gadget->b_hnp_enable && fsm->a_bus_suspend)
 280                         otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 281                 break;
 282         case OTG_STATE_B_WAIT_ACON:
 283                 if (fsm->a_conn)
 284                         otg_set_state(fsm, OTG_STATE_B_HOST);
 285                 else if (!fsm->id || !fsm->b_sess_vld)
 286                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 287                 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 288                         fsm->b_ase0_brst_tmout = 0;
 289                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 290                 }
 291                 break;
 292         case OTG_STATE_B_HOST:
 293                 if (!fsm->id || !fsm->b_sess_vld)
 294                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 295                 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
 296                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 297                 break;
 298         case OTG_STATE_A_IDLE:
 299                 if (fsm->id)
 300                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 301                 else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
 302                           fsm->a_srp_det || fsm->adp_change || fsm->power_up))
 303                         otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 304                 break;
 305         case OTG_STATE_A_WAIT_VRISE:
 306                 if (fsm->a_vbus_vld)
 307                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 308                 else if (fsm->id || fsm->a_bus_drop ||
 309                                 fsm->a_wait_vrise_tmout)
 310                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 311                 break;
 312         case OTG_STATE_A_WAIT_BCON:
 313                 if (!fsm->a_vbus_vld)
 314                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 315                 else if (fsm->b_conn)
 316                         otg_set_state(fsm, OTG_STATE_A_HOST);
 317                 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
 318                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 319                 break;
 320         case OTG_STATE_A_HOST:
 321                 if (fsm->id || fsm->a_bus_drop)
 322                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 323                 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
 324                                 fsm->otg->host->b_hnp_enable)
 325                         otg_set_state(fsm, OTG_STATE_A_SUSPEND);
 326                 else if (!fsm->b_conn)
 327                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 328                 else if (!fsm->a_vbus_vld)
 329                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 330                 break;
 331         case OTG_STATE_A_SUSPEND:
 332                 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
 333                         otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 334                 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
 335                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 336                 else if (fsm->a_bus_req || fsm->b_bus_resume)
 337                         otg_set_state(fsm, OTG_STATE_A_HOST);
 338                 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 339                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 340                 else if (!fsm->a_vbus_vld)
 341                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 342                 break;
 343         case OTG_STATE_A_PERIPHERAL:
 344                 if (fsm->id || fsm->a_bus_drop)
 345                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 346                 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
 347                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 348                 else if (!fsm->a_vbus_vld)
 349                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 350                 break;
 351         case OTG_STATE_A_WAIT_VFALL:
 352                 if (fsm->a_wait_vfall_tmout)
 353                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 354                 break;
 355         case OTG_STATE_A_VBUS_ERR:
 356                 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 357                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 358                 break;
 359         default:
 360                 break;
 361         }
 362         mutex_unlock(&fsm->lock);
 363
 364         VDBG("quit statemachine, changed = %d\n", state_changed);
 365         return state_changed;
 366 }
 367 EXPORT_SYMBOL_GPL(otg_statemachine);