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