drivers/usb/phy/phy-fsm-usb.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/spinlock.h>
  27 #include <linux/delay.h>
  28 #include <linux/usb.h>
  29 #include <linux/usb/gadget.h>
  30 #include <linux/usb/otg.h>
  31
  32 #include "phy-fsm-usb.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 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                 break;
  75         case OTG_STATE_B_SRP_INIT:
  76                 fsm->b_srp_done = 0;
  77                 break;
  78         case OTG_STATE_B_PERIPHERAL:
  79                 break;
  80         case OTG_STATE_B_WAIT_ACON:
  81                 otg_del_timer(fsm, B_ASE0_BRST);
  82                 fsm->b_ase0_brst_tmout = 0;
  83                 break;
  84         case OTG_STATE_B_HOST:
  85                 break;
  86         case OTG_STATE_A_IDLE:
  87                 break;
  88         case OTG_STATE_A_WAIT_VRISE:
  89                 otg_del_timer(fsm, A_WAIT_VRISE);
  90                 fsm->a_wait_vrise_tmout = 0;
  91                 break;
  92         case OTG_STATE_A_WAIT_BCON:
  93                 otg_del_timer(fsm, A_WAIT_BCON);
  94                 fsm->a_wait_bcon_tmout = 0;
  95                 break;
  96         case OTG_STATE_A_HOST:
  97                 otg_del_timer(fsm, A_WAIT_ENUM);
  98                 break;
  99         case OTG_STATE_A_SUSPEND:
 100                 otg_del_timer(fsm, A_AIDL_BDIS);
 101                 fsm->a_aidl_bdis_tmout = 0;
 102                 fsm->a_suspend_req_inf = 0;
 103                 break;
 104         case OTG_STATE_A_PERIPHERAL:
 105                 otg_del_timer(fsm, A_BIDL_ADIS);
 106                 fsm->a_bidl_adis_tmout = 0;
 107                 break;
 108         case OTG_STATE_A_WAIT_VFALL:
 109                 otg_del_timer(fsm, A_WAIT_VFALL);
 110                 fsm->a_wait_vfall_tmout = 0;
 111                 otg_del_timer(fsm, A_WAIT_VRISE);
 112                 break;
 113         case OTG_STATE_A_VBUS_ERR:
 114                 break;
 115         default:
 116                 break;
 117         }
 118 }
 119
 120 /* Called when entering a state */
 121 int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 122 {
 123         state_changed = 1;
 124         if (fsm->otg->phy->state == new_state)
 125                 return 0;
 126         VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 127         otg_leave_state(fsm, fsm->otg->phy->state);
 128         switch (new_state) {
 129         case OTG_STATE_B_IDLE:
 130                 otg_drv_vbus(fsm, 0);
 131                 otg_chrg_vbus(fsm, 0);
 132                 otg_loc_conn(fsm, 0);
 133                 otg_loc_sof(fsm, 0);
 134                 otg_set_protocol(fsm, PROTO_UNDEF);
 135                 otg_add_timer(fsm, B_SE0_SRP);
 136                 break;
 137         case OTG_STATE_B_SRP_INIT:
 138                 otg_start_pulse(fsm);
 139                 otg_loc_sof(fsm, 0);
 140                 otg_set_protocol(fsm, PROTO_UNDEF);
 141                 otg_add_timer(fsm, B_SRP_FAIL);
 142                 break;
 143         case OTG_STATE_B_PERIPHERAL:
 144                 otg_chrg_vbus(fsm, 0);
 145                 otg_loc_conn(fsm, 1);
 146                 otg_loc_sof(fsm, 0);
 147                 otg_set_protocol(fsm, PROTO_GADGET);
 148                 break;
 149         case OTG_STATE_B_WAIT_ACON:
 150                 otg_chrg_vbus(fsm, 0);
 151                 otg_loc_conn(fsm, 0);
 152                 otg_loc_sof(fsm, 0);
 153                 otg_set_protocol(fsm, PROTO_HOST);
 154                 otg_add_timer(fsm, B_ASE0_BRST);
 155                 fsm->a_bus_suspend = 0;
 156                 break;
 157         case OTG_STATE_B_HOST:
 158                 otg_chrg_vbus(fsm, 0);
 159                 otg_loc_conn(fsm, 0);
 160                 otg_loc_sof(fsm, 1);
 161                 otg_set_protocol(fsm, PROTO_HOST);
 162                 usb_bus_start_enum(fsm->otg->host,
 163                                 fsm->otg->host->otg_port);
 164                 break;
 165         case OTG_STATE_A_IDLE:
 166                 otg_drv_vbus(fsm, 0);
 167                 otg_chrg_vbus(fsm, 0);
 168                 otg_loc_conn(fsm, 0);
 169                 otg_loc_sof(fsm, 0);
 170                 otg_set_protocol(fsm, PROTO_HOST);
 171                 break;
 172         case OTG_STATE_A_WAIT_VRISE:
 173                 otg_drv_vbus(fsm, 1);
 174                 otg_loc_conn(fsm, 0);
 175                 otg_loc_sof(fsm, 0);
 176                 otg_set_protocol(fsm, PROTO_HOST);
 177                 otg_add_timer(fsm, A_WAIT_VRISE);
 178                 break;
 179         case OTG_STATE_A_WAIT_BCON:
 180                 otg_drv_vbus(fsm, 1);
 181                 otg_loc_conn(fsm, 0);
 182                 otg_loc_sof(fsm, 0);
 183                 otg_set_protocol(fsm, PROTO_HOST);
 184                 otg_add_timer(fsm, A_WAIT_BCON);
 185                 break;
 186         case OTG_STATE_A_HOST:
 187                 otg_drv_vbus(fsm, 1);
 188                 otg_loc_conn(fsm, 0);
 189                 otg_loc_sof(fsm, 1);
 190                 otg_set_protocol(fsm, PROTO_HOST);
 191                 /*
 192                  * When HNP is triggered while a_bus_req = 0, a_host will
 193                  * suspend too fast to complete a_set_b_hnp_en
 194                  */
 195                 if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
 196                         otg_add_timer(fsm, A_WAIT_ENUM);
 197                 break;
 198         case OTG_STATE_A_SUSPEND:
 199                 otg_drv_vbus(fsm, 1);
 200                 otg_loc_conn(fsm, 0);
 201                 otg_loc_sof(fsm, 0);
 202                 otg_set_protocol(fsm, PROTO_HOST);
 203                 otg_add_timer(fsm, A_AIDL_BDIS);
 204
 205                 break;
 206         case OTG_STATE_A_PERIPHERAL:
 207                 otg_loc_conn(fsm, 1);
 208                 otg_loc_sof(fsm, 0);
 209                 otg_set_protocol(fsm, PROTO_GADGET);
 210                 otg_drv_vbus(fsm, 1);
 211                 otg_add_timer(fsm, A_BIDL_ADIS);
 212                 break;
 213         case OTG_STATE_A_WAIT_VFALL:
 214                 otg_drv_vbus(fsm, 0);
 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_WAIT_VFALL);
 219                 break;
 220         case OTG_STATE_A_VBUS_ERR:
 221                 otg_drv_vbus(fsm, 0);
 222                 otg_loc_conn(fsm, 0);
 223                 otg_loc_sof(fsm, 0);
 224                 otg_set_protocol(fsm, PROTO_UNDEF);
 225                 break;
 226         default:
 227                 break;
 228         }
 229
 230         fsm->otg->phy->state = new_state;
 231         return 0;
 232 }
 233
 234 /* State change judgement */
 235 int otg_statemachine(struct otg_fsm *fsm)
 236 {
 237         enum usb_otg_state state;
 238         unsigned long flags;
 239
 240         spin_lock_irqsave(&fsm->lock, flags);
 241
 242         state = fsm->otg->phy->state;
 243         state_changed = 0;
 244         /* State machine state change judgement */
 245
 246         switch (state) {
 247         case OTG_STATE_UNDEFINED:
 248                 VDBG("fsm->id = %d\n", fsm->id);
 249                 if (fsm->id)
 250                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 251                 else
 252                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 253                 break;
 254         case OTG_STATE_B_IDLE:
 255                 if (!fsm->id)
 256                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 257                 else if (fsm->b_sess_vld && fsm->otg->gadget)
 258                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 259                 else if (fsm->b_bus_req && fsm->b_ssend_srp && fsm->b_se0_srp)
 260                         otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 261                 break;
 262         case OTG_STATE_B_SRP_INIT:
 263                 if (!fsm->id || fsm->b_srp_done)
 264                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 265                 break;
 266         case OTG_STATE_B_PERIPHERAL:
 267                 if (!fsm->id || !fsm->b_sess_vld)
 268                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 269                 else if (fsm->b_bus_req && fsm->otg->
 270                                 gadget->b_hnp_enable && fsm->a_bus_suspend)
 271                         otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 272                 break;
 273         case OTG_STATE_B_WAIT_ACON:
 274                 if (fsm->a_conn)
 275                         otg_set_state(fsm, OTG_STATE_B_HOST);
 276                 else if (!fsm->id || !fsm->b_sess_vld)
 277                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 278                 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 279                         fsm->b_ase0_brst_tmout = 0;
 280                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 281                 }
 282                 break;
 283         case OTG_STATE_B_HOST:
 284                 if (!fsm->id || !fsm->b_sess_vld)
 285                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 286                 else if (!fsm->b_bus_req || !fsm->a_conn)
 287                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 288                 break;
 289         case OTG_STATE_A_IDLE:
 290                 if (fsm->id)
 291                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 292                 else if (!fsm->a_bus_drop && (fsm->a_bus_req || fsm->a_srp_det))
 293                         otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 294                 break;
 295         case OTG_STATE_A_WAIT_VRISE:
 296                 if (fsm->id || fsm->a_bus_drop || fsm->a_vbus_vld ||
 297                                 fsm->a_wait_vrise_tmout) {
 298                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 299                 }
 300                 break;
 301         case OTG_STATE_A_WAIT_BCON:
 302                 if (!fsm->a_vbus_vld)
 303                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 304                 else if (fsm->b_conn)
 305                         otg_set_state(fsm, OTG_STATE_A_HOST);
 306                 else if (fsm->id | fsm->a_bus_drop | fsm->a_wait_bcon_tmout)
 307                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 308                 break;
 309         case OTG_STATE_A_HOST:
 310                 if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
 311                                 fsm->otg->host->b_hnp_enable)
 312                         otg_set_state(fsm, OTG_STATE_A_SUSPEND);
 313                 else if (fsm->id || !fsm->b_conn || fsm->a_bus_drop)
 314                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 315                 else if (!fsm->a_vbus_vld)
 316                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 317                 break;
 318         case OTG_STATE_A_SUSPEND:
 319                 if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
 320                         otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 321                 else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
 322                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 323                 else if (fsm->a_bus_req || fsm->b_bus_resume)
 324                         otg_set_state(fsm, OTG_STATE_A_HOST);
 325                 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 326                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 327                 else if (!fsm->a_vbus_vld)
 328                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 329                 break;
 330         case OTG_STATE_A_PERIPHERAL:
 331                 if (fsm->id || fsm->a_bus_drop)
 332                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 333                 else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
 334                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 335                 else if (!fsm->a_vbus_vld)
 336                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 337                 break;
 338         case OTG_STATE_A_WAIT_VFALL:
 339                 if (fsm->a_wait_vfall_tmout || fsm->id || fsm->a_bus_req ||
 340                                 (!fsm->a_sess_vld && !fsm->b_conn))
 341                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 342                 break;
 343         case OTG_STATE_A_VBUS_ERR:
 344                 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 345                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 346                 break;
 347         default:
 348                 break;
 349         }
 350         spin_unlock_irqrestore(&fsm->lock, flags);
 351
 352         VDBG("quit statemachine, changed = %d\n", state_changed);
 353         return state_changed;
 354 }