linux/drivers/usb/common/usb-otg-fsm.c
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   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 */
  35static 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/* Called when leaving a state.  Do state clean up jobs here */
  66static void otg_leave_state(struct otg_fsm *fsm, enum usb_otg_state old_state)
  67{
  68        switch (old_state) {
  69        case OTG_STATE_B_IDLE:
  70                otg_del_timer(fsm, B_SE0_SRP);
  71                fsm->b_se0_srp = 0;
  72                fsm->adp_sns = 0;
  73                fsm->adp_prb = 0;
  74                break;
  75        case OTG_STATE_B_SRP_INIT:
  76                fsm->data_pulse = 0;
  77                fsm->b_srp_done = 0;
  78                break;
  79        case OTG_STATE_B_PERIPHERAL:
  80                if (fsm->otg->gadget)
  81                        fsm->otg->gadget->host_request_flag = 0;
  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                if (fsm->otg->gadget)
 112                        fsm->otg->gadget->host_request_flag = 0;
 113                break;
 114        case OTG_STATE_A_WAIT_VFALL:
 115                otg_del_timer(fsm, A_WAIT_VFALL);
 116                fsm->a_wait_vfall_tmout = 0;
 117                otg_del_timer(fsm, A_WAIT_VRISE);
 118                break;
 119        case OTG_STATE_A_VBUS_ERR:
 120                break;
 121        default:
 122                break;
 123        }
 124}
 125
 126static void otg_hnp_polling_work(struct work_struct *work)
 127{
 128        struct otg_fsm *fsm = container_of(to_delayed_work(work),
 129                                struct otg_fsm, hnp_polling_work);
 130        struct usb_device *udev;
 131        enum usb_otg_state state = fsm->otg->state;
 132        u8 flag;
 133        int retval;
 134
 135        if (state != OTG_STATE_A_HOST && state != OTG_STATE_B_HOST)
 136                return;
 137
 138        udev = usb_hub_find_child(fsm->otg->host->root_hub, 1);
 139        if (!udev) {
 140                dev_err(fsm->otg->host->controller,
 141                        "no usb dev connected, can't start HNP polling\n");
 142                return;
 143        }
 144
 145        *fsm->host_req_flag = 0;
 146        /* Get host request flag from connected USB device */
 147        retval = usb_control_msg(udev,
 148                                usb_rcvctrlpipe(udev, 0),
 149                                USB_REQ_GET_STATUS,
 150                                USB_DIR_IN | USB_RECIP_DEVICE,
 151                                0,
 152                                OTG_STS_SELECTOR,
 153                                fsm->host_req_flag,
 154                                1,
 155                                USB_CTRL_GET_TIMEOUT);
 156        if (retval != 1) {
 157                dev_err(&udev->dev, "Get one byte OTG status failed\n");
 158                return;
 159        }
 160
 161        flag = *fsm->host_req_flag;
 162        if (flag == 0) {
 163                /* Continue HNP polling */
 164                schedule_delayed_work(&fsm->hnp_polling_work,
 165                                        msecs_to_jiffies(T_HOST_REQ_POLL));
 166                return;
 167        } else if (flag != HOST_REQUEST_FLAG) {
 168                dev_err(&udev->dev, "host request flag %d is invalid\n", flag);
 169                return;
 170        }
 171
 172        /* Host request flag is set */
 173        if (state == OTG_STATE_A_HOST) {
 174                /* Set b_hnp_enable */
 175                if (!fsm->otg->host->b_hnp_enable) {
 176                        retval = usb_control_msg(udev,
 177                                        usb_sndctrlpipe(udev, 0),
 178                                        USB_REQ_SET_FEATURE, 0,
 179                                        USB_DEVICE_B_HNP_ENABLE,
 180                                        0, NULL, 0,
 181                                        USB_CTRL_SET_TIMEOUT);
 182                        if (retval >= 0)
 183                                fsm->otg->host->b_hnp_enable = 1;
 184                }
 185                fsm->a_bus_req = 0;
 186        } else if (state == OTG_STATE_B_HOST) {
 187                fsm->b_bus_req = 0;
 188        }
 189
 190        otg_statemachine(fsm);
 191}
 192
 193static void otg_start_hnp_polling(struct otg_fsm *fsm)
 194{
 195        /*
 196         * The memory of host_req_flag should be allocated by
 197         * controller driver, otherwise, hnp polling is not started.
 198         */
 199        if (!fsm->host_req_flag)
 200                return;
 201
 202        INIT_DELAYED_WORK(&fsm->hnp_polling_work, otg_hnp_polling_work);
 203        schedule_delayed_work(&fsm->hnp_polling_work,
 204                                        msecs_to_jiffies(T_HOST_REQ_POLL));
 205}
 206
 207/* Called when entering a state */
 208static int otg_set_state(struct otg_fsm *fsm, enum usb_otg_state new_state)
 209{
 210        if (fsm->otg->state == new_state)
 211                return 0;
 212        VDBG("Set state: %s\n", usb_otg_state_string(new_state));
 213        otg_leave_state(fsm, fsm->otg->state);
 214        switch (new_state) {
 215        case OTG_STATE_B_IDLE:
 216                otg_drv_vbus(fsm, 0);
 217                otg_chrg_vbus(fsm, 0);
 218                otg_loc_conn(fsm, 0);
 219                otg_loc_sof(fsm, 0);
 220                /*
 221                 * Driver is responsible for starting ADP probing
 222                 * if ADP sensing times out.
 223                 */
 224                otg_start_adp_sns(fsm);
 225                otg_set_protocol(fsm, PROTO_UNDEF);
 226                otg_add_timer(fsm, B_SE0_SRP);
 227                break;
 228        case OTG_STATE_B_SRP_INIT:
 229                otg_start_pulse(fsm);
 230                otg_loc_sof(fsm, 0);
 231                otg_set_protocol(fsm, PROTO_UNDEF);
 232                otg_add_timer(fsm, B_SRP_FAIL);
 233                break;
 234        case OTG_STATE_B_PERIPHERAL:
 235                otg_chrg_vbus(fsm, 0);
 236                otg_loc_sof(fsm, 0);
 237                otg_set_protocol(fsm, PROTO_GADGET);
 238                otg_loc_conn(fsm, 1);
 239                break;
 240        case OTG_STATE_B_WAIT_ACON:
 241                otg_chrg_vbus(fsm, 0);
 242                otg_loc_conn(fsm, 0);
 243                otg_loc_sof(fsm, 0);
 244                otg_set_protocol(fsm, PROTO_HOST);
 245                otg_add_timer(fsm, B_ASE0_BRST);
 246                fsm->a_bus_suspend = 0;
 247                break;
 248        case OTG_STATE_B_HOST:
 249                otg_chrg_vbus(fsm, 0);
 250                otg_loc_conn(fsm, 0);
 251                otg_loc_sof(fsm, 1);
 252                otg_set_protocol(fsm, PROTO_HOST);
 253                usb_bus_start_enum(fsm->otg->host,
 254                                fsm->otg->host->otg_port);
 255                otg_start_hnp_polling(fsm);
 256                break;
 257        case OTG_STATE_A_IDLE:
 258                otg_drv_vbus(fsm, 0);
 259                otg_chrg_vbus(fsm, 0);
 260                otg_loc_conn(fsm, 0);
 261                otg_loc_sof(fsm, 0);
 262                otg_start_adp_prb(fsm);
 263                otg_set_protocol(fsm, PROTO_HOST);
 264                break;
 265        case OTG_STATE_A_WAIT_VRISE:
 266                otg_drv_vbus(fsm, 1);
 267                otg_loc_conn(fsm, 0);
 268                otg_loc_sof(fsm, 0);
 269                otg_set_protocol(fsm, PROTO_HOST);
 270                otg_add_timer(fsm, A_WAIT_VRISE);
 271                break;
 272        case OTG_STATE_A_WAIT_BCON:
 273                otg_drv_vbus(fsm, 1);
 274                otg_loc_conn(fsm, 0);
 275                otg_loc_sof(fsm, 0);
 276                otg_set_protocol(fsm, PROTO_HOST);
 277                otg_add_timer(fsm, A_WAIT_BCON);
 278                break;
 279        case OTG_STATE_A_HOST:
 280                otg_drv_vbus(fsm, 1);
 281                otg_loc_conn(fsm, 0);
 282                otg_loc_sof(fsm, 1);
 283                otg_set_protocol(fsm, PROTO_HOST);
 284                /*
 285                 * When HNP is triggered while a_bus_req = 0, a_host will
 286                 * suspend too fast to complete a_set_b_hnp_en
 287                 */
 288                if (!fsm->a_bus_req || fsm->a_suspend_req_inf)
 289                        otg_add_timer(fsm, A_WAIT_ENUM);
 290                otg_start_hnp_polling(fsm);
 291                break;
 292        case OTG_STATE_A_SUSPEND:
 293                otg_drv_vbus(fsm, 1);
 294                otg_loc_conn(fsm, 0);
 295                otg_loc_sof(fsm, 0);
 296                otg_set_protocol(fsm, PROTO_HOST);
 297                otg_add_timer(fsm, A_AIDL_BDIS);
 298
 299                break;
 300        case OTG_STATE_A_PERIPHERAL:
 301                otg_loc_sof(fsm, 0);
 302                otg_set_protocol(fsm, PROTO_GADGET);
 303                otg_drv_vbus(fsm, 1);
 304                otg_loc_conn(fsm, 1);
 305                otg_add_timer(fsm, A_BIDL_ADIS);
 306                break;
 307        case OTG_STATE_A_WAIT_VFALL:
 308                otg_drv_vbus(fsm, 0);
 309                otg_loc_conn(fsm, 0);
 310                otg_loc_sof(fsm, 0);
 311                otg_set_protocol(fsm, PROTO_HOST);
 312                otg_add_timer(fsm, A_WAIT_VFALL);
 313                break;
 314        case OTG_STATE_A_VBUS_ERR:
 315                otg_drv_vbus(fsm, 0);
 316                otg_loc_conn(fsm, 0);
 317                otg_loc_sof(fsm, 0);
 318                otg_set_protocol(fsm, PROTO_UNDEF);
 319                break;
 320        default:
 321                break;
 322        }
 323
 324        fsm->otg->state = new_state;
 325        fsm->state_changed = 1;
 326        return 0;
 327}
 328
 329/* State change judgement */
 330int otg_statemachine(struct otg_fsm *fsm)
 331{
 332        enum usb_otg_state state;
 333
 334        mutex_lock(&fsm->lock);
 335
 336        state = fsm->otg->state;
 337        fsm->state_changed = 0;
 338        /* State machine state change judgement */
 339
 340        switch (state) {
 341        case OTG_STATE_UNDEFINED:
 342                VDBG("fsm->id = %d\n", fsm->id);
 343                if (fsm->id)
 344                        otg_set_state(fsm, OTG_STATE_B_IDLE);
 345                else
 346                        otg_set_state(fsm, OTG_STATE_A_IDLE);
 347                break;
 348        case OTG_STATE_B_IDLE:
 349                if (!fsm->id)
 350                        otg_set_state(fsm, OTG_STATE_A_IDLE);
 351                else if (fsm->b_sess_vld && fsm->otg->gadget)
 352                        otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 353                else if ((fsm->b_bus_req || fsm->adp_change || fsm->power_up) &&
 354                                fsm->b_ssend_srp && fsm->b_se0_srp)
 355                        otg_set_state(fsm, OTG_STATE_B_SRP_INIT);
 356                break;
 357        case OTG_STATE_B_SRP_INIT:
 358                if (!fsm->id || fsm->b_srp_done)
 359                        otg_set_state(fsm, OTG_STATE_B_IDLE);
 360                break;
 361        case OTG_STATE_B_PERIPHERAL:
 362                if (!fsm->id || !fsm->b_sess_vld)
 363                        otg_set_state(fsm, OTG_STATE_B_IDLE);
 364                else if (fsm->b_bus_req && fsm->otg->
 365                                gadget->b_hnp_enable && fsm->a_bus_suspend)
 366                        otg_set_state(fsm, OTG_STATE_B_WAIT_ACON);
 367                break;
 368        case OTG_STATE_B_WAIT_ACON:
 369                if (fsm->a_conn)
 370                        otg_set_state(fsm, OTG_STATE_B_HOST);
 371                else if (!fsm->id || !fsm->b_sess_vld)
 372                        otg_set_state(fsm, OTG_STATE_B_IDLE);
 373                else if (fsm->a_bus_resume || fsm->b_ase0_brst_tmout) {
 374                        fsm->b_ase0_brst_tmout = 0;
 375                        otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 376                }
 377                break;
 378        case OTG_STATE_B_HOST:
 379                if (!fsm->id || !fsm->b_sess_vld)
 380                        otg_set_state(fsm, OTG_STATE_B_IDLE);
 381                else if (!fsm->b_bus_req || !fsm->a_conn || fsm->test_device)
 382                        otg_set_state(fsm, OTG_STATE_B_PERIPHERAL);
 383                break;
 384        case OTG_STATE_A_IDLE:
 385                if (fsm->id)
 386                        otg_set_state(fsm, OTG_STATE_B_IDLE);
 387                else if (!fsm->a_bus_drop && (fsm->a_bus_req ||
 388                          fsm->a_srp_det || fsm->adp_change || fsm->power_up))
 389                        otg_set_state(fsm, OTG_STATE_A_WAIT_VRISE);
 390                break;
 391        case OTG_STATE_A_WAIT_VRISE:
 392                if (fsm->a_vbus_vld)
 393                        otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 394                else if (fsm->id || fsm->a_bus_drop ||
 395                                fsm->a_wait_vrise_tmout)
 396                        otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 397                break;
 398        case OTG_STATE_A_WAIT_BCON:
 399                if (!fsm->a_vbus_vld)
 400                        otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 401                else if (fsm->b_conn)
 402                        otg_set_state(fsm, OTG_STATE_A_HOST);
 403                else if (fsm->id || fsm->a_bus_drop || fsm->a_wait_bcon_tmout)
 404                        otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 405                break;
 406        case OTG_STATE_A_HOST:
 407                if (fsm->id || fsm->a_bus_drop)
 408                        otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 409                else if ((!fsm->a_bus_req || fsm->a_suspend_req_inf) &&
 410                                fsm->otg->host->b_hnp_enable)
 411                        otg_set_state(fsm, OTG_STATE_A_SUSPEND);
 412                else if (!fsm->b_conn)
 413                        otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 414                else if (!fsm->a_vbus_vld)
 415                        otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 416                break;
 417        case OTG_STATE_A_SUSPEND:
 418                if (!fsm->b_conn && fsm->otg->host->b_hnp_enable)
 419                        otg_set_state(fsm, OTG_STATE_A_PERIPHERAL);
 420                else if (!fsm->b_conn && !fsm->otg->host->b_hnp_enable)
 421                        otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 422                else if (fsm->a_bus_req || fsm->b_bus_resume)
 423                        otg_set_state(fsm, OTG_STATE_A_HOST);
 424                else if (fsm->id || fsm->a_bus_drop || fsm->a_aidl_bdis_tmout)
 425                        otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 426                else if (!fsm->a_vbus_vld)
 427                        otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 428                break;
 429        case OTG_STATE_A_PERIPHERAL:
 430                if (fsm->id || fsm->a_bus_drop)
 431                        otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 432                else if (fsm->a_bidl_adis_tmout || fsm->b_bus_suspend)
 433                        otg_set_state(fsm, OTG_STATE_A_WAIT_BCON);
 434                else if (!fsm->a_vbus_vld)
 435                        otg_set_state(fsm, OTG_STATE_A_VBUS_ERR);
 436                break;
 437        case OTG_STATE_A_WAIT_VFALL:
 438                if (fsm->a_wait_vfall_tmout)
 439                        otg_set_state(fsm, OTG_STATE_A_IDLE);
 440                break;
 441        case OTG_STATE_A_VBUS_ERR:
 442                if (fsm->id || fsm->a_bus_drop || fsm->a_clr_err)
 443                        otg_set_state(fsm, OTG_STATE_A_WAIT_VFALL);
 444                break;
 445        default:
 446                break;
 447        }
 448        mutex_unlock(&fsm->lock);
 449
 450        VDBG("quit statemachine, changed = %d\n", fsm->state_changed);
 451        return fsm->state_changed;
 452}
 453EXPORT_SYMBOL_GPL(otg_statemachine);
 454MODULE_LICENSE("GPL");
 455