drivers/usb/otg/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/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 #include <linux/types.h>
  32
  33 #include "otg_fsm.h"
  34
  35 /* Change USB protocol when there is a protocol change */
  36 static int otg_set_protocol(struct otg_fsm *fsm, int protocol)
  37 {
  38         int ret = 0;
  39
  40         if (fsm->protocol != protocol) {
  41                 VDBG("Changing role fsm->protocol= %d; new protocol= %d\n",
  42                         fsm->protocol, protocol);
  43                 /* stop old protocol */
  44                 if (fsm->protocol == PROTO_HOST)
  45                         ret = fsm->ops->start_host(fsm, 0);
  46                 else if (fsm->protocol == PROTO_GADGET)
  47                         ret = fsm->ops->start_gadget(fsm, 0);
  48                 if (ret)
  49                         return ret;
  50
  51                 /* start new protocol */
  52                 if (protocol == PROTO_HOST)
  53                         ret = fsm->ops->start_host(fsm, 1);
  54                 else if (protocol == PROTO_GADGET)
  55                         ret = fsm->ops->start_gadget(fsm, 1);
  56                 if (ret)
  57                         return ret;
  58
  59                 fsm->protocol = protocol;
  60                 return 0;
  61         }
  62
  63         return 0;
  64 }
  65
  66 static int state_changed;
  67
  68 /* Called when leaving a state.  Do state clean up jobs here */
  69 void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
  70 {
  71         switch (old_state) {
  72         case OTG_STATE_B_IDLE:
  73                 otg_del_timer(fsm, b_se0_srp_tmr);
  74                 fsm->b_se0_srp = 0;
  75                 break;
  76         case OTG_STATE_B_SRP_INIT:
  77                 fsm->b_srp_done = 0;
  78                 break;
  79         case OTG_STATE_B_PERIPHERAL:
  80                 break;
  81         case OTG_STATE_B_WAIT_ACON:
  82                 otg_del_timer(fsm, b_ase0_brst_tmr);
  83                 fsm->b_ase0_brst_tmout = 0;
  84                 break;
  85         case OTG_STATE_B_HOST:
  86                 break;
  87         case OTG_STATE_A_IDLE:
  88                 break;
  89         case OTG_STATE_A_WAIT_VRISE:
  90                 otg_del_timer(fsm, a_wait_vrise_tmr);
  91                 fsm->a_wait_vrise_tmout = 0;
  92                 break;
  93         case OTG_STATE_A_WAIT_BCON:
  94                 otg_del_timer(fsm, a_wait_bcon_tmr);
  95                 fsm->a_wait_bcon_tmout = 0;
  96                 break;
  97         case OTG_STATE_A_HOST:
  98                 otg_del_timer(fsm, a_wait_enum_tmr);
  99                 break;
 100         case OTG_STATE_A_SUSPEND:
 101                 otg_del_timer(fsm, a_aidl_bdis_tmr);
 102                 fsm->a_aidl_bdis_tmout = 0;
 103                 fsm->a_suspend_req = 0;
 104                 break;
 105         case OTG_STATE_A_PERIPHERAL:
 106                 break;
 107         case OTG_STATE_A_WAIT_VFALL:
 108                 otg_del_timer(fsm, a_wait_vrise_tmr);
 109                 break;
 110         case OTG_STATE_A_VBUS_ERR:
 111                 break;
 112         default:
 113                 break;
 114         }
 115 }
 116
 117 /* Called when entering a state */
 118 int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 119 {
 120         state_changed = 1;
 121         if (fsm->transceiver->state == new_state)
 122                 return 0;
 123         VDBG("Set state: %s\n", otg_state_string(new_state));
 124         otg_leave_state(fsm, fsm->transceiver->state);
 125         switch (new_state) {
 126         case OTG_STATE_B_IDLE:
 127                 otg_drv_vbus(fsm, 0);
 128                 otg_chrg_vbus(fsm, 0);
 129                 otg_loc_conn(fsm, 0);
 130                 otg_loc_sof(fsm, 0);
 131                 otg_set_protocol(fsm, PROTO_UNDEF);
 132                 otg_add_timer(fsm, b_se0_srp_tmr);
 133                 break;
 134         case OTG_STATE_B_SRP_INIT:
 135                 otg_start_pulse(fsm);
 136                 otg_loc_sof(fsm, 0);
 137                 otg_set_protocol(fsm, PROTO_UNDEF);
 138                 otg_add_timer(fsm, b_srp_fail_tmr);
 139                 break;
 140         case OTG_STATE_B_PERIPHERAL:
 141                 otg_chrg_vbus(fsm, 0);
 142                 otg_loc_conn(fsm, 1);
 143                 otg_loc_sof(fsm, 0);
 144                 otg_set_protocol(fsm, PROTO_GADGET);
 145                 break;
 146         case OTG_STATE_B_WAIT_ACON:
 147                 otg_chrg_vbus(fsm, 0);
 148                 otg_loc_conn(fsm, 0);
 149                 otg_loc_sof(fsm, 0);
 150                 otg_set_protocol(fsm, PROTO_HOST);
 151                 otg_add_timer(fsm, b_ase0_brst_tmr);
 152                 fsm->a_bus_suspend = 0;
 153                 break;
 154         case OTG_STATE_B_HOST:
 155                 otg_chrg_vbus(fsm, 0);
 156                 otg_loc_conn(fsm, 0);
 157                 otg_loc_sof(fsm, 1);
 158                 otg_set_protocol(fsm, PROTO_HOST);
 159                 usb_bus_start_enum(fsm->transceiver->host,
 160                                 fsm->transceiver->host->otg_port);
 161                 break;
 162         case OTG_STATE_A_IDLE:
 163                 otg_drv_vbus(fsm, 0);
 164                 otg_chrg_vbus(fsm, 0);
 165                 otg_loc_conn(fsm, 0);
 166                 otg_loc_sof(fsm, 0);
 167                 otg_set_protocol(fsm, PROTO_HOST);
 168                 break;
 169         case OTG_STATE_A_WAIT_VRISE:
 170                 otg_drv_vbus(fsm, 1);
 171                 otg_loc_conn(fsm, 0);
 172                 otg_loc_sof(fsm, 0);
 173                 otg_set_protocol(fsm, PROTO_HOST);
 174                 otg_add_timer(fsm, a_wait_vrise_tmr);
 175                 break;
 176         case OTG_STATE_A_WAIT_BCON:
 177                 otg_drv_vbus(fsm, 1);
 178                 otg_loc_conn(fsm, 0);
 179                 otg_loc_sof(fsm, 0);
 180                 otg_set_protocol(fsm, PROTO_HOST);
 181                 otg_add_timer(fsm, a_wait_bcon_tmr);
 182                 break;
 183         case OTG_STATE_A_HOST:
 184                 otg_drv_vbus(fsm, 1);
 185                 otg_loc_conn(fsm, 0);
 186                 otg_loc_sof(fsm, 1);
 187                 otg_set_protocol(fsm, PROTO_HOST);
 188                 /*
 189                  * When HNP is triggered while a_bus_req = 0, a_host will
 190                  * suspend too fast to complete a_set_b_hnp_en
 191                  */
 192                 if (!fsm->a_bus_req || fsm->a_suspend_req)
 193                         otg_add_timer(fsm, a_wait_enum_tmr);
 194                 break;
 195         case OTG_STATE_A_SUSPEND:
 196                 otg_drv_vbus(fsm, 1);
 197                 otg_loc_conn(fsm, 0);
 198                 otg_loc_sof(fsm, 0);
 199                 otg_set_protocol(fsm, PROTO_HOST);
 200                 otg_add_timer(fsm, a_aidl_bdis_tmr);
 201
 202                 break;
 203         case OTG_STATE_A_PERIPHERAL:
 204                 otg_loc_conn(fsm, 1);
 205                 otg_loc_sof(fsm, 0);
 206                 otg_set_protocol(fsm, PROTO_GADGET);
 207                 otg_drv_vbus(fsm, 1);
 208                 break;
 209         case OTG_STATE_A_WAIT_VFALL:
 210                 otg_drv_vbus(fsm, 0);
 211                 otg_loc_conn(fsm, 0);
 212                 otg_loc_sof(fsm, 0);
 213                 otg_set_protocol(fsm, PROTO_HOST);
 214                 break;
 215         case OTG_STATE_A_VBUS_ERR:
 216                 otg_drv_vbus(fsm, 0);
 217                 otg_loc_conn(fsm, 0);
 218                 otg_loc_sof(fsm, 0);
 219                 otg_set_protocol(fsm, PROTO_UNDEF);
 220                 break;
 221         default:
 222                 break;
 223         }
 224
 225         fsm->transceiver->state = new_state;
 226         return 0;
 227 }
 228
 229 /* State change judgement */
 230 int otg_statemachine(struct otg_fsm *fsm)
 231 {
 232         enum usb_otg_state state;
 233         unsigned long flags;
 234
 235         spin_lock_irqsave(&fsm->lock, flags);
 236
 237         state = fsm->transceiver->state;
 238         state_changed = 0;
 239         /* State machine state change judgement */
 240
 241         switch (state) {
 242         case OTG_STATE_UNDEFINED:
 243                 VDBG("fsm->id = %d\n", fsm->id);
 244                 if (fsm->id)
 245                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 246                 else
 247                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 248                 break;
 249         case OTG_STATE_B_IDLE:
 250                 if (!fsm->id)
 251                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 252                 else if (fsm->b_sess_vld && fsm->transceiver->gadget)
 253                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 254                 else if (fsm->b_bus_req && fsm->b_sess_end && fsm->b_se0_srp)
 255                         otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 256                 break;
 257         case OTG_STATE_B_SRP_INIT:
 258                 if (!fsm->id || fsm->b_srp_done)
 259                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 260                 break;
 261         case OTG_STATE_B_PERIPHERAL:
 262                 if (!fsm->id || !fsm->b_sess_vld)
 263                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 264                 else if (fsm->b_bus_req && fsm->transceiver->
 265                                 gadget->b_hnp_enable && fsm->a_bus_suspend)
 266                         otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 267                 break;
 268         case OTG_STATE_B_WAIT_ACON:
 269                 if (fsm->a_conn)
 270                         otg_set_state(fsm, OTG_STATE_B_HOST);
 271                 else if (!fsm->id || !fsm->b_sess_vld)
 272                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 273                 else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 274                         fsm->b_ase0_brst_tmout = 0;
 275                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 276                 }
 277                 break;
 278         case OTG_STATE_B_HOST:
 279                 if (!fsm->id || !fsm->b_sess_vld)
 280                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 281                 else if (!fsm->b_bus_req || !fsm->a_conn)
 282                         otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 283                 break;
 284         case OTG_STATE_A_IDLE:
 285                 if (fsm->id)
 286                         otg_set_state(fsm, OTG_STATE_B_IDLE);
 287                 else if (!fsm->a_bus_drop && (fsm->a_bus_req || fsm->a_srp_det))
 288                         otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 289                 break;
 290         case OTG_STATE_A_WAIT_VRISE:
 291                 if (fsm->id || fsm->a_bus_drop || fsm->a_vbus_vld ||
 292                                 fsm->a_wait_vrise_tmout) {
 293                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 294                 }
 295                 break;
 296         case OTG_STATE_A_WAIT_BCON:
 297                 if (!fsm->a_vbus_vld)
 298                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 299                 else if (fsm->b_conn)
 300                         otg_set_state(fsm, OTG_STATE_A_HOST);
 301                 else if (fsm->id | fsm->a_bus_drop | fsm->a_wait_bcon_tmout)
 302                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 303                 break;
 304         case OTG_STATE_A_HOST:
 305                 if ((!fsm->a_bus_req || fsm->a_suspend_req) &&
 306                                 fsm->transceiver->host->b_hnp_enable)
 307                         otg_set_state(fsm, OTG_STATE_A_SUSPEND);
 308                 else if (fsm->id || !fsm->b_conn || fsm->a_bus_drop)
 309                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 310                 else if (!fsm->a_vbus_vld)
 311                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 312                 break;
 313         case OTG_STATE_A_SUSPEND:
 314                 if (!fsm->b_conn && fsm->transceiver->host->b_hnp_enable)
 315                         otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 316                 else if (!fsm->b_conn && !fsm->transceiver->host->b_hnp_enable)
 317                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 318                 else if (fsm->a_bus_req || fsm->b_bus_resume)
 319                         otg_set_state(fsm, OTG_STATE_A_HOST);
 320                 else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 321                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 322                 else if (!fsm->a_vbus_vld)
 323                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 324                 break;
 325         case OTG_STATE_A_PERIPHERAL:
 326                 if (fsm->id || fsm->a_bus_drop)
 327                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 328                 else if (fsm->b_bus_suspend)
 329                         otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 330                 else if (!fsm->a_vbus_vld)
 331                         otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 332                 break;
 333         case OTG_STATE_A_WAIT_VFALL:
 334                 if (fsm->id || fsm->a_bus_req || (!fsm->a_sess_vld &&
 335                                         !fsm->b_conn))
 336                         otg_set_state(fsm, OTG_STATE_A_IDLE);
 337                 break;
 338         case OTG_STATE_A_VBUS_ERR:
 339                 if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 340                         otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 341                 break;
 342         default:
 343                 break;
 344         }
 345         spin_unlock_irqrestore(&fsm->lock, flags);
 346
 347         VDBG("quit statemachine, changed = %d\n", state_changed);
 348         return state_changed;
 349 }