kernel/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 /* Change USB protocol when there is a protocol change */
  35 static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
  36 {
  37         int ret = 0;
  38
  39         if (fsm->protocol != protocol) {
  40                 VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
  41                         fsm->protocol, protocol);
  42                 /* stop old protocol */
  43                 if (fsm->protocol == PROTO_HOST)
  44                         ret = otg_start_host(fsm, 0);
  45                 else if (fsm->protocol == PROTO_GADGET)
  46                         ret = otg_start_gadget(fsm, 0);
  47                 if (ret)
  48                         return ret;
  49
  50                 /* start new protocol */
  51                 if (protocol == PROTO_HOST)
  52                         ret = otg_start_host(fsm, 1);
  53                 else if (protocol == PROTO_GADGET)
  54                         ret = otg_start_gadget(fsm, 1);
  55                 if (ret)
  56                         return ret;
  57
  58                 fsm->protocol = protocol;
  59                 return 0;
  60         }
  61
  62         return 0;
  63 }
  64
  65 static int state_changed;
  66
  67 /* Called when leaving a state.  Do state clean up jobs here */
  68 static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
  69 {
  70         switch (old_state) {
  71         case OTG_STATE_B_IDLE:
  72                 otg_del_timer(fsm, B_SE0_SRP);
  73                 fsm->b_se0_srp = 0;
  74                 fsm->adp_sns = 0;
  75                 fsm->adp_prb = 0;
  76                 break;
  77         case OTG_STATE_B_SRP_INIT:
  78                 fsm->data_pulse = 0;
  79                 fsm->b_srp_done = 0;
  80                 break;
  81         case OTG_STATE_B_PERIPHERAL:
  82                 break;
  83         case OTG_STATE_B_WAIT_ACON:
  84                 otg_del_timer(fsm, B_ASE0_BRST);
  85                 fsm->b_ase0_brst_tmout = 0;
  86                 break;
  87         case OTG_STATE_B_HOST:
  88                 break;
  89         case OTG_STATE_A_IDLE:
  90                 fsm->adp_prb = 0;
  91                 break;
  92         case OTG_STATE_A_WAIT_VRISE:
  93                 otg_del_timer(fsm, A_WAIT_VRISE);
  94                 fsm->a_wait_vrise_tmout = 0;
  95                 break;
  96         case OTG_STATE_A_WAIT_BCON:
  97                 otg_del_timer(fsm, A_WAIT_BCON);
  98                 fsm->a_wait_bcon_tmout = 0;
  99                 break;
 100         case OTG_STATE_A_HOST:
 101                 otg_del_timer(fsm, A_WAIT_ENUM);
 102                 break;
 103         case OTG_STATE_A_SUSPEND:
 104                 otg_del_timer(fsm, A_AIDL_BDIS);
 105                 fsm->a_aidl_bdis_tmout = 0;
 106                 fsm->a_suspend_req_inf = 0;
 107                 break;
 108         case OTG_STATE_A_PERIPHERAL:
 109                 otg_del_timer(fsm, A_BIDL_ADIS);
 110                 fsm->a_bidl_adis_tmout = 0;
 111                 break;
 112         case OTG_STATE_A_WAIT_VFALL:
 113                 otg_del_timer(fsm, A_WAIT_VFALL);
 114                 fsm->a_wait_vfall_tmout = 0;
 115                 otg_del_timer(fsm, A_WAIT_VRISE);
 116                 break;
 117         case OTG_STATE_A_VBUS_ERR:
 118                 break;
 119         default:
 120                 break;
 121         }
 122 }
 123
 124 /* Called when entering a state */
 125 static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 126 {
 127         state_changed = 1;
 128         if (fsm->otg->state == new_state)
 129                 return 0;
 130         VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 131         otg_leave_state(fsm, fsm->otg->state);
 132         switch (new_state) {
 133         case OTG_STATE_B_IDLE:
 134                 otg_drv_vbus(fsm, 0);
 135                 otg_chrg_vbus(fsm, 0);
 136                 otg_loc_conn(fsm, 0);
 137                 otg_loc_sof(fsm, 0);
 138                 /*
 139                  * Driver is responsible for starting ADP probing
 140                  * if ADP sensing times out.
 141                  */
 142                 otg_start_adp_sns(fsm);
 143                 otg_set_protocol(fsm, PROTO_UNDEF);
 144                 otg_add_timer(fsm, B_SE0_SRP);
 145                 break;
 146         case OTG_STATE_B_SRP_INIT:
 147                 otg_start_pulse(fsm);
 148                 otg_loc_sof(fsm, 0);
 149                 otg_set_protocol(fsm, PROTO_UNDEF);
 150                 otg_add_timer(fsm, B_SRP_FAIL);
 151                 break;
 152         case OTG_STATE_B_PERIPHERAL:
 153                 otg_chrg_vbus(fsm, 0);
 154                 otg_loc_sof(fsm, 0);
 155                 otg_set_protocol(fsm, PROTO_GADGET);
 156                 otg_loc_conn(fsm, 1);
 157                 break;
 158         case OTG_STATE_B_WAIT_ACON:
 159                 otg_chrg_vbus(fsm, 0);
 160                 otg_loc_conn(fsm, 0);
 161                 otg_loc_sof(fsm, 0);
 162                 otg_set_protocol(fsm, PROTO_HOST);
 163                 otg_add_timer(fsm, B_ASE0_BRST);
 164                 fsm->a_bus_suspend = 0;
 165                 break;
 166         case OTG_STATE_B_HOST:
 167                 otg_chrg_vbus(fsm, 0);
 168                 otg_loc_conn(fsm, 0);
 169                 otg_loc_sof(fsm, 1);
 170                 otg_set_protocol(fsm, PROTO_HOST);
 171                 usb_bus_start_enum(fsm->otg->host,
 172                                 fsm->otg->host->otg_port);
 173                 break;
 174         case OTG_STATE_A_IDLE:
 175                 otg_drv_vbus(fsm, 0);
 176                 otg_chrg_vbus(fsm, 0);
 177                 otg_loc_conn(fsm, 0);
 178                 otg_loc_sof(fsm, 0);
 179                 otg_start_adp_prb(fsm);
 180                 otg_set_protocol(fsm, PROTO_HOST);
 181                 break;
 182         case OTG_STATE_A_WAIT_VRISE:
 183                 otg_drv_vbus(fsm, 1);
 184                 otg_loc_conn(fsm, 0);
 185                 otg_loc_sof(fsm, 0);
 186                 otg_set_protocol(fsm, PROTO_HOST);
 187                 otg_add_timer(fsm, A_WAIT_VRISE);
 188                 break;
 189         case OTG_STATE_A_WAIT_BCON:
 190                 otg_drv_vbus(fsm, 1);
 191                 otg_loc_conn(fsm, 0);
 192                 otg_loc_sof(fsm, 0);
 193                 otg_set_protocol(fsm, PROTO_HOST);
 194                 otg_add_timer(fsm, A_WAIT_BCON);
 195                 break;
 196         case OTG_STATE_A_HOST:
 197                 otg_drv_vbus(fsm, 1);
 198                 otg_loc_conn(fsm, 0);
 199                 otg_loc_sof(fsm, 1);
 200                 otg_set_protocol(fsm, PROTO_HOST);
 201                 /*
 202                  * When HNP is triggered while a_bus_req = 0, a_host will
 203                  * suspend too fast to complete a_set_b_hnp_en
 204                  */
 205                 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
 206                         otg_add_timer(fsm, A_WAIT_ENUM);
 207                 break;
 208         case OTG_STATE_A_SUSPEND:
 209                 otg_drv_vbus(fsm, 1);
 210                 otg_loc_conn(fsm, 0);
 211                 otg_loc_sof(fsm, 0);
 212                 otg_set_protocol(fsm, PROTO_HOST);
 213                 otg_add_timer(fsm, A_AIDL_BDIS);
 214
 215                 break;
 216         case OTG_STATE_A_PERIPHERAL:
 217                 otg_loc_sof(fsm, 0);
 218                 otg_set_protocol(fsm, PROTO_GADGET);
 219                 otg_drv_vbus(fsm, 1);
 220                 otg_loc_conn(fsm, 1);
 221                 otg_add_timer(fsm, A_BIDL_ADIS);
 222                 break;
 223         case OTG_STATE_A_WAIT_VFALL:
 224                 otg_drv_vbus(fsm, 0);
 225                 otg_loc_conn(fsm, 0);
 226                 otg_loc_sof(fsm, 0);
 227                 otg_set_protocol(fsm, PROTO_HOST);
 228                 otg_add_timer(fsm, A_WAIT_VFALL);
 229                 break;
 230         case OTG_STATE_A_VBUS_ERR:
 231                 otg_drv_vbus(fsm, 0);
 232                 otg_loc_conn(fsm, 0);
 233                 otg_loc_sof(fsm, 0);
 234                 otg_set_protocol(fsm, PROTO_UNDEF);
 235                 break;
 236         default:
 237                 break;
 238         }
 239
 240         fsm->otg->state = new_state;
 241         return 0;
 242 }
 243
 244 /* State change judgement */
 245 int otg_statemachine(struct otg_fsm *fsm)
 246 {
 247         enum usb_otg_state state;
 248
 249         mutex_lock(&fsm->lock);
 250
 251         state = fsm->otg->state;
 252         state_changed = 0;
 253         /* State machine state change judgement */
 254
 255         switch (state) {
 256         case OTG_STATE_UNDEFINED:
 257                 VDBG("fsm->id = %d\n", fsm->id);
 258                 if (fsm->id)
 259                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 260                 else
 261                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 262                 break;
 263         case OTG_STATE_B_IDLE:
 264                 if (!fsm->id)
 265                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 266                 else if (fsm->b_sess_vld && fsm->otg->gadget)
 267                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 268                 else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
 269                                 fsm->b_ssend_srp && fsm->b_se0_srp)
 270                         otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 271                 break;
 272         case OTG_STATE_B_SRP_INIT:
 273                 if (!fsm->id || fsm->b_srp_done)
 274                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 275                 break;
 276         case OTG_STATE_B_PERIPHERAL:
 277                 if (!fsm->id || !fsm->b_sess_vld)
 278                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 279                 else if (fsm->b_bus_req && fsm->otg->
 280                                 gadget->b_hnp_enable && fsm->a_bus_suspend)
 281                         otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 282                 break;
 283         case OTG_STATE_B_WAIT_ACON:
 284                 if (fsm->a_conn)
 285                         otg_set_state(fsm, OTG_STATE_B_HOST);
 286                 else if (!fsm->id || !fsm->b_sess_vld)
 287                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 288                 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 289                         fsm->b_ase0_brst_tmout = 0;
 290                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 291                 }
 292                 break;
 293         case OTG_STATE_B_HOST:
 294                 if (!fsm->id || !fsm->b_sess_vld)
 295                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 296                 else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
 297                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 298                 break;
 299         case OTG_STATE_A_IDLE:
 300                 if (fsm->id)
 301                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 302                 else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
 303                           fsm->a_srp_det || fsm->adp_change || fsm->power_up))
 304                         otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 305                 break;
 306         case OTG_STATE_A_WAIT_VRISE:
 307                 if (fsm->a_vbus_vld)
 308                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 309                 else if (fsm->id || fsm->a_bus_drop ||
 310                                 fsm->a_wait_vrise_tmout)
 311                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 312                 break;
 313         case OTG_STATE_A_WAIT_BCON:
 314                 if (!fsm->a_vbus_vld)
 315                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 316                 else if (fsm->b_conn)
 317                         otg_set_state(fsm, OTG_STATE_A_HOST);
 318                 else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
 319                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 320                 break;
 321         case OTG_STATE_A_HOST:
 322                 if (fsm->id || fsm->a_bus_drop)
 323                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 324                 else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
 325                                 fsm->otg->host->b_hnp_enable)
 326                         otg_set_state(fsm, OTG_STATE_A_SUSPEND);
 327                 else if (!fsm->b_conn)
 328                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 329                 else if (!fsm->a_vbus_vld)
 330                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 331                 break;
 332         case OTG_STATE_A_SUSPEND:
 333                 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
 334                         otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 335                 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
 336                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 337                 else if (fsm->a_bus_req || fsm->b_bus_resume)
 338                         otg_set_state(fsm, OTG_STATE_A_HOST);
 339                 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 340                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 341                 else if (!fsm->a_vbus_vld)
 342                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 343                 break;
 344         case OTG_STATE_A_PERIPHERAL:
 345                 if (fsm->id || fsm->a_bus_drop)
 346                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 347                 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
 348                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 349                 else if (!fsm->a_vbus_vld)
 350                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 351                 break;
 352         case OTG_STATE_A_WAIT_VFALL:
 353                 if (fsm->a_wait_vfall_tmout)
 354                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 355                 break;
 356         case OTG_STATE_A_VBUS_ERR:
 357                 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 358                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 359                 break;
 360         default:
 361                 break;
 362         }
 363         mutex_unlock(&fsm->lock);
 364
 365         VDBG("quit statemachine, changed = %d\n", state_changed);
 366         return state_changed;
 367 }
 368 EXPORT_SYMBOL_GPL(otg_statemachine);
 369 MODULE_LICENSE("GPL");