drivers/usb/phy/phy-mv-usb.c

   1 /*
   2  * Copyright (C) 2011 Marvell International Ltd. All rights reserved.
   3  * Author: Chao Xie <chao.xie@marvell.com>
   4  *         Neil Zhang <zhangwm@marvell.com>
   5  *
   6  * This program is free software; you can redistribute  it and/or modify it
   7  * under  the terms of  the GNU General  Public License as published by the
   8  * Free Software Foundation;  either version 2 of the  License, or (at your
   9  * option) any later version.
  10  */
  11
  12 #include <linux/module.h>
  13 #include <linux/kernel.h>
  14 #include <linux/init.h>
  15 #include <linux/io.h>
  16 #include <linux/uaccess.h>
  17 #include <linux/device.h>
  18 #include <linux/proc_fs.h>
  19 #include <linux/clk.h>
  20 #include <linux/workqueue.h>
  21 #include <linux/platform_device.h>
  22
  23 #include <linux/usb.h>
  24 #include <linux/usb/ch9.h>
  25 #include <linux/usb/otg.h>
  26 #include <linux/usb/gadget.h>
  27 #include <linux/usb/hcd.h>
  28 #include <linux/platform_data/mv_usb.h>
  29
  30 #include "phy-mv-usb.h"
  31
  32 #define DRIVER_DESC     "Marvell USB OTG transceiver driver"
  33 #define DRIVER_VERSION  "Jan 20, 2010"
  34
  35 MODULE_DESCRIPTION(DRIVER_DESC);
  36 MODULE_VERSION(DRIVER_VERSION);
  37 MODULE_LICENSE("GPL");
  38
  39 static const char driver_name[] = "mv-otg";
  40
  41 static char *state_string[] = {
  42         "undefined",
  43         "b_idle",
  44         "b_srp_init",
  45         "b_peripheral",
  46         "b_wait_acon",
  47         "b_host",
  48         "a_idle",
  49         "a_wait_vrise",
  50         "a_wait_bcon",
  51         "a_host",
  52         "a_suspend",
  53         "a_peripheral",
  54         "a_wait_vfall",
  55         "a_vbus_err"
  56 };
  57
  58 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
  59 {
  60         struct mv_otg *mvotg = container_of(otg->phy, struct mv_otg, phy);
  61         if (mvotg->pdata->set_vbus == NULL)
  62                 return -ENODEV;
  63
  64         return mvotg->pdata->set_vbus(on);
  65 }
  66
  67 static int mv_otg_set_host(struct usb_otg *otg,
  68                            struct usb_bus *host)
  69 {
  70         otg->host = host;
  71
  72         return 0;
  73 }
  74
  75 static int mv_otg_set_peripheral(struct usb_otg *otg,
  76                                  struct usb_gadget *gadget)
  77 {
  78         otg->gadget = gadget;
  79
  80         return 0;
  81 }
  82
  83 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
  84                                      unsigned long delay)
  85 {
  86         dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
  87         if (!mvotg->qwork)
  88                 return;
  89
  90         queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
  91 }
  92
  93 static void mv_otg_timer_await_bcon(unsigned long data)
  94 {
  95         struct mv_otg *mvotg = (struct mv_otg *) data;
  96
  97         mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
  98
  99         dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
 100
 101         if (spin_trylock(&mvotg->wq_lock)) {
 102                 mv_otg_run_state_machine(mvotg, 0);
 103                 spin_unlock(&mvotg->wq_lock);
 104         }
 105 }
 106
 107 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
 108 {
 109         struct timer_list *timer;
 110
 111         if (id >= OTG_TIMER_NUM)
 112                 return -EINVAL;
 113
 114         timer = &mvotg->otg_ctrl.timer[id];
 115
 116         if (timer_pending(timer))
 117                 del_timer(timer);
 118
 119         return 0;
 120 }
 121
 122 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
 123                             unsigned long interval,
 124                             void (*callback) (unsigned long))
 125 {
 126         struct timer_list *timer;
 127
 128         if (id >= OTG_TIMER_NUM)
 129                 return -EINVAL;
 130
 131         timer = &mvotg->otg_ctrl.timer[id];
 132         if (timer_pending(timer)) {
 133                 dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
 134                 return -EBUSY;
 135         }
 136
 137         init_timer(timer);
 138         timer->data = (unsigned long) mvotg;
 139         timer->function = callback;
 140         timer->expires = jiffies + interval;
 141         add_timer(timer);
 142
 143         return 0;
 144 }
 145
 146 static int mv_otg_reset(struct mv_otg *mvotg)
 147 {
 148         unsigned int loops;
 149         u32 tmp;
 150
 151         /* Stop the controller */
 152         tmp = readl(&mvotg->op_regs->usbcmd);
 153         tmp &= ~USBCMD_RUN_STOP;
 154         writel(tmp, &mvotg->op_regs->usbcmd);
 155
 156         /* Reset the controller to get default values */
 157         writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
 158
 159         loops = 500;
 160         while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
 161                 if (loops == 0) {
 162                         dev_err(&mvotg->pdev->dev,
 163                                 "Wait for RESET completed TIMEOUT\n");
 164                         return -ETIMEDOUT;
 165                 }
 166                 loops--;
 167                 udelay(20);
 168         }
 169
 170         writel(0x0, &mvotg->op_regs->usbintr);
 171         tmp = readl(&mvotg->op_regs->usbsts);
 172         writel(tmp, &mvotg->op_regs->usbsts);
 173
 174         return 0;
 175 }
 176
 177 static void mv_otg_init_irq(struct mv_otg *mvotg)
 178 {
 179         u32 otgsc;
 180
 181         mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
 182             | OTGSC_INTR_A_VBUS_VALID;
 183         mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
 184             | OTGSC_INTSTS_A_VBUS_VALID;
 185
 186         if (mvotg->pdata->vbus == NULL) {
 187                 mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
 188                     | OTGSC_INTR_B_SESSION_END;
 189                 mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
 190                     | OTGSC_INTSTS_B_SESSION_END;
 191         }
 192
 193         if (mvotg->pdata->id == NULL) {
 194                 mvotg->irq_en |= OTGSC_INTR_USB_ID;
 195                 mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
 196         }
 197
 198         otgsc = readl(&mvotg->op_regs->otgsc);
 199         otgsc |= mvotg->irq_en;
 200         writel(otgsc, &mvotg->op_regs->otgsc);
 201 }
 202
 203 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
 204 {
 205 #ifdef CONFIG_USB
 206         struct usb_otg *otg = mvotg->phy.otg;
 207         struct usb_hcd *hcd;
 208
 209         if (!otg->host)
 210                 return;
 211
 212         dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
 213
 214         hcd = bus_to_hcd(otg->host);
 215
 216         if (on) {
 217                 usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
 218                 device_wakeup_enable(hcd->self.controller);
 219         } else {
 220                 usb_remove_hcd(hcd);
 221         }
 222 #endif /* CONFIG_USB */
 223 }
 224
 225 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
 226 {
 227         struct usb_otg *otg = mvotg->phy.otg;
 228
 229         if (!otg->gadget)
 230                 return;
 231
 232         dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
 233
 234         if (on)
 235                 usb_gadget_vbus_connect(otg->gadget);
 236         else
 237                 usb_gadget_vbus_disconnect(otg->gadget);
 238 }
 239
 240 static void otg_clock_enable(struct mv_otg *mvotg)
 241 {
 242         clk_prepare_enable(mvotg->clk);
 243 }
 244
 245 static void otg_clock_disable(struct mv_otg *mvotg)
 246 {
 247         clk_disable_unprepare(mvotg->clk);
 248 }
 249
 250 static int mv_otg_enable_internal(struct mv_otg *mvotg)
 251 {
 252         int retval = 0;
 253
 254         if (mvotg->active)
 255                 return 0;
 256
 257         dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
 258
 259         otg_clock_enable(mvotg);
 260         if (mvotg->pdata->phy_init) {
 261                 retval = mvotg->pdata->phy_init(mvotg->phy_regs);
 262                 if (retval) {
 263                         dev_err(&mvotg->pdev->dev,
 264                                 "init phy error %d\n", retval);
 265                         otg_clock_disable(mvotg);
 266                         return retval;
 267                 }
 268         }
 269         mvotg->active = 1;
 270
 271         return 0;
 272
 273 }
 274
 275 static int mv_otg_enable(struct mv_otg *mvotg)
 276 {
 277         if (mvotg->clock_gating)
 278                 return mv_otg_enable_internal(mvotg);
 279
 280         return 0;
 281 }
 282
 283 static void mv_otg_disable_internal(struct mv_otg *mvotg)
 284 {
 285         if (mvotg->active) {
 286                 dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
 287                 if (mvotg->pdata->phy_deinit)
 288                         mvotg->pdata->phy_deinit(mvotg->phy_regs);
 289                 otg_clock_disable(mvotg);
 290                 mvotg->active = 0;
 291         }
 292 }
 293
 294 static void mv_otg_disable(struct mv_otg *mvotg)
 295 {
 296         if (mvotg->clock_gating)
 297                 mv_otg_disable_internal(mvotg);
 298 }
 299
 300 static void mv_otg_update_inputs(struct mv_otg *mvotg)
 301 {
 302         struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
 303         u32 otgsc;
 304
 305         otgsc = readl(&mvotg->op_regs->otgsc);
 306
 307         if (mvotg->pdata->vbus) {
 308                 if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
 309                         otg_ctrl->b_sess_vld = 1;
 310                         otg_ctrl->b_sess_end = 0;
 311                 } else {
 312                         otg_ctrl->b_sess_vld = 0;
 313                         otg_ctrl->b_sess_end = 1;
 314                 }
 315         } else {
 316                 otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
 317                 otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
 318         }
 319
 320         if (mvotg->pdata->id)
 321                 otg_ctrl->id = !!mvotg->pdata->id->poll();
 322         else
 323                 otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
 324
 325         if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
 326                 otg_ctrl->a_bus_req = 1;
 327
 328         otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
 329         otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
 330
 331         dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
 332         dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
 333         dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
 334         dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
 335         dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
 336         dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
 337 }
 338
 339 static void mv_otg_update_state(struct mv_otg *mvotg)
 340 {
 341         struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
 342         struct usb_phy *phy = &mvotg->phy;
 343         int old_state = phy->state;
 344
 345         switch (old_state) {
 346         case OTG_STATE_UNDEFINED:
 347                 phy->state = OTG_STATE_B_IDLE;
 348                 /* FALL THROUGH */
 349         case OTG_STATE_B_IDLE:
 350                 if (otg_ctrl->id == 0)
 351                         phy->state = OTG_STATE_A_IDLE;
 352                 else if (otg_ctrl->b_sess_vld)
 353                         phy->state = OTG_STATE_B_PERIPHERAL;
 354                 break;
 355         case OTG_STATE_B_PERIPHERAL:
 356                 if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
 357                         phy->state = OTG_STATE_B_IDLE;
 358                 break;
 359         case OTG_STATE_A_IDLE:
 360                 if (otg_ctrl->id)
 361                         phy->state = OTG_STATE_B_IDLE;
 362                 else if (!(otg_ctrl->a_bus_drop) &&
 363                          (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
 364                         phy->state = OTG_STATE_A_WAIT_VRISE;
 365                 break;
 366         case OTG_STATE_A_WAIT_VRISE:
 367                 if (otg_ctrl->a_vbus_vld)
 368                         phy->state = OTG_STATE_A_WAIT_BCON;
 369                 break;
 370         case OTG_STATE_A_WAIT_BCON:
 371                 if (otg_ctrl->id || otg_ctrl->a_bus_drop
 372                     || otg_ctrl->a_wait_bcon_timeout) {
 373                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 374                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 375                         phy->state = OTG_STATE_A_WAIT_VFALL;
 376                         otg_ctrl->a_bus_req = 0;
 377                 } else if (!otg_ctrl->a_vbus_vld) {
 378                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 379                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 380                         phy->state = OTG_STATE_A_VBUS_ERR;
 381                 } else if (otg_ctrl->b_conn) {
 382                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 383                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 384                         phy->state = OTG_STATE_A_HOST;
 385                 }
 386                 break;
 387         case OTG_STATE_A_HOST:
 388                 if (otg_ctrl->id || !otg_ctrl->b_conn
 389                     || otg_ctrl->a_bus_drop)
 390                         phy->state = OTG_STATE_A_WAIT_BCON;
 391                 else if (!otg_ctrl->a_vbus_vld)
 392                         phy->state = OTG_STATE_A_VBUS_ERR;
 393                 break;
 394         case OTG_STATE_A_WAIT_VFALL:
 395                 if (otg_ctrl->id
 396                     || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
 397                     || otg_ctrl->a_bus_req)
 398                         phy->state = OTG_STATE_A_IDLE;
 399                 break;
 400         case OTG_STATE_A_VBUS_ERR:
 401                 if (otg_ctrl->id || otg_ctrl->a_clr_err
 402                     || otg_ctrl->a_bus_drop) {
 403                         otg_ctrl->a_clr_err = 0;
 404                         phy->state = OTG_STATE_A_WAIT_VFALL;
 405                 }
 406                 break;
 407         default:
 408                 break;
 409         }
 410 }
 411
 412 static void mv_otg_work(struct work_struct *work)
 413 {
 414         struct mv_otg *mvotg;
 415         struct usb_phy *phy;
 416         struct usb_otg *otg;
 417         int old_state;
 418
 419         mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
 420
 421 run:
 422         /* work queue is single thread, or we need spin_lock to protect */
 423         phy = &mvotg->phy;
 424         otg = phy->otg;
 425         old_state = phy->state;
 426
 427         if (!mvotg->active)
 428                 return;
 429
 430         mv_otg_update_inputs(mvotg);
 431         mv_otg_update_state(mvotg);
 432
 433         if (old_state != phy->state) {
 434                 dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
 435                          state_string[old_state],
 436                          state_string[phy->state]);
 437
 438                 switch (phy->state) {
 439                 case OTG_STATE_B_IDLE:
 440                         otg->default_a = 0;
 441                         if (old_state == OTG_STATE_B_PERIPHERAL)
 442                                 mv_otg_start_periphrals(mvotg, 0);
 443                         mv_otg_reset(mvotg);
 444                         mv_otg_disable(mvotg);
 445                         break;
 446                 case OTG_STATE_B_PERIPHERAL:
 447                         mv_otg_enable(mvotg);
 448                         mv_otg_start_periphrals(mvotg, 1);
 449                         break;
 450                 case OTG_STATE_A_IDLE:
 451                         otg->default_a = 1;
 452                         mv_otg_enable(mvotg);
 453                         if (old_state == OTG_STATE_A_WAIT_VFALL)
 454                                 mv_otg_start_host(mvotg, 0);
 455                         mv_otg_reset(mvotg);
 456                         break;
 457                 case OTG_STATE_A_WAIT_VRISE:
 458                         mv_otg_set_vbus(otg, 1);
 459                         break;
 460                 case OTG_STATE_A_WAIT_BCON:
 461                         if (old_state != OTG_STATE_A_HOST)
 462                                 mv_otg_start_host(mvotg, 1);
 463                         mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
 464                                          T_A_WAIT_BCON,
 465                                          mv_otg_timer_await_bcon);
 466                         /*
 467                          * Now, we directly enter A_HOST. So set b_conn = 1
 468                          * here. In fact, it need host driver to notify us.
 469                          */
 470                         mvotg->otg_ctrl.b_conn = 1;
 471                         break;
 472                 case OTG_STATE_A_HOST:
 473                         break;
 474                 case OTG_STATE_A_WAIT_VFALL:
 475                         /*
 476                          * Now, we has exited A_HOST. So set b_conn = 0
 477                          * here. In fact, it need host driver to notify us.
 478                          */
 479                         mvotg->otg_ctrl.b_conn = 0;
 480                         mv_otg_set_vbus(otg, 0);
 481                         break;
 482                 case OTG_STATE_A_VBUS_ERR:
 483                         break;
 484                 default:
 485                         break;
 486                 }
 487                 goto run;
 488         }
 489 }
 490
 491 static irqreturn_t mv_otg_irq(int irq, void *dev)
 492 {
 493         struct mv_otg *mvotg = dev;
 494         u32 otgsc;
 495
 496         otgsc = readl(&mvotg->op_regs->otgsc);
 497         writel(otgsc, &mvotg->op_regs->otgsc);
 498
 499         /*
 500          * if we have vbus, then the vbus detection for B-device
 501          * will be done by mv_otg_inputs_irq().
 502          */
 503         if (mvotg->pdata->vbus)
 504                 if ((otgsc & OTGSC_STS_USB_ID) &&
 505                     !(otgsc & OTGSC_INTSTS_USB_ID))
 506                         return IRQ_NONE;
 507
 508         if ((otgsc & mvotg->irq_status) == 0)
 509                 return IRQ_NONE;
 510
 511         mv_otg_run_state_machine(mvotg, 0);
 512
 513         return IRQ_HANDLED;
 514 }
 515
 516 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
 517 {
 518         struct mv_otg *mvotg = dev;
 519
 520         /* The clock may disabled at this time */
 521         if (!mvotg->active) {
 522                 mv_otg_enable(mvotg);
 523                 mv_otg_init_irq(mvotg);
 524         }
 525
 526         mv_otg_run_state_machine(mvotg, 0);
 527
 528         return IRQ_HANDLED;
 529 }
 530
 531 static ssize_t
 532 get_a_bus_req(struct device *dev, struct device_attribute *attr, char *buf)
 533 {
 534         struct mv_otg *mvotg = dev_get_drvdata(dev);
 535         return scnprintf(buf, PAGE_SIZE, "%d\n",
 536                          mvotg->otg_ctrl.a_bus_req);
 537 }
 538
 539 static ssize_t
 540 set_a_bus_req(struct device *dev, struct device_attribute *attr,
 541               const char *buf, size_t count)
 542 {
 543         struct mv_otg *mvotg = dev_get_drvdata(dev);
 544
 545         if (count > 2)
 546                 return -1;
 547
 548         /* We will use this interface to change to A device */
 549         if (mvotg->phy.state != OTG_STATE_B_IDLE
 550             && mvotg->phy.state != OTG_STATE_A_IDLE)
 551                 return -1;
 552
 553         /* The clock may disabled and we need to set irq for ID detected */
 554         mv_otg_enable(mvotg);
 555         mv_otg_init_irq(mvotg);
 556
 557         if (buf[0] == '1') {
 558                 mvotg->otg_ctrl.a_bus_req = 1;
 559                 mvotg->otg_ctrl.a_bus_drop = 0;
 560                 dev_dbg(&mvotg->pdev->dev,
 561                         "User request: a_bus_req = 1\n");
 562
 563                 if (spin_trylock(&mvotg->wq_lock)) {
 564                         mv_otg_run_state_machine(mvotg, 0);
 565                         spin_unlock(&mvotg->wq_lock);
 566                 }
 567         }
 568
 569         return count;
 570 }
 571
 572 static DEVICE_ATTR(a_bus_req, S_IRUGO | S_IWUSR, get_a_bus_req,
 573                    set_a_bus_req);
 574
 575 static ssize_t
 576 set_a_clr_err(struct device *dev, struct device_attribute *attr,
 577               const char *buf, size_t count)
 578 {
 579         struct mv_otg *mvotg = dev_get_drvdata(dev);
 580         if (!mvotg->phy.otg->default_a)
 581                 return -1;
 582
 583         if (count > 2)
 584                 return -1;
 585
 586         if (buf[0] == '1') {
 587                 mvotg->otg_ctrl.a_clr_err = 1;
 588                 dev_dbg(&mvotg->pdev->dev,
 589                         "User request: a_clr_err = 1\n");
 590         }
 591
 592         if (spin_trylock(&mvotg->wq_lock)) {
 593                 mv_otg_run_state_machine(mvotg, 0);
 594                 spin_unlock(&mvotg->wq_lock);
 595         }
 596
 597         return count;
 598 }
 599
 600 static DEVICE_ATTR(a_clr_err, S_IWUSR, NULL, set_a_clr_err);
 601
 602 static ssize_t
 603 get_a_bus_drop(struct device *dev, struct device_attribute *attr,
 604                char *buf)
 605 {
 606         struct mv_otg *mvotg = dev_get_drvdata(dev);
 607         return scnprintf(buf, PAGE_SIZE, "%d\n",
 608                          mvotg->otg_ctrl.a_bus_drop);
 609 }
 610
 611 static ssize_t
 612 set_a_bus_drop(struct device *dev, struct device_attribute *attr,
 613                const char *buf, size_t count)
 614 {
 615         struct mv_otg *mvotg = dev_get_drvdata(dev);
 616         if (!mvotg->phy.otg->default_a)
 617                 return -1;
 618
 619         if (count > 2)
 620                 return -1;
 621
 622         if (buf[0] == '0') {
 623                 mvotg->otg_ctrl.a_bus_drop = 0;
 624                 dev_dbg(&mvotg->pdev->dev,
 625                         "User request: a_bus_drop = 0\n");
 626         } else if (buf[0] == '1') {
 627                 mvotg->otg_ctrl.a_bus_drop = 1;
 628                 mvotg->otg_ctrl.a_bus_req = 0;
 629                 dev_dbg(&mvotg->pdev->dev,
 630                         "User request: a_bus_drop = 1\n");
 631                 dev_dbg(&mvotg->pdev->dev,
 632                         "User request: and a_bus_req = 0\n");
 633         }
 634
 635         if (spin_trylock(&mvotg->wq_lock)) {
 636                 mv_otg_run_state_machine(mvotg, 0);
 637                 spin_unlock(&mvotg->wq_lock);
 638         }
 639
 640         return count;
 641 }
 642
 643 static DEVICE_ATTR(a_bus_drop, S_IRUGO | S_IWUSR,
 644                    get_a_bus_drop, set_a_bus_drop);
 645
 646 static struct attribute *inputs_attrs[] = {
 647         &dev_attr_a_bus_req.attr,
 648         &dev_attr_a_clr_err.attr,
 649         &dev_attr_a_bus_drop.attr,
 650         NULL,
 651 };
 652
 653 static struct attribute_group inputs_attr_group = {
 654         .name = "inputs",
 655         .attrs = inputs_attrs,
 656 };
 657
 658 static int mv_otg_remove(struct platform_device *pdev)
 659 {
 660         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 661
 662         sysfs_remove_group(&mvotg->pdev->dev.kobj, &inputs_attr_group);
 663
 664         if (mvotg->qwork) {
 665                 flush_workqueue(mvotg->qwork);
 666                 destroy_workqueue(mvotg->qwork);
 667         }
 668
 669         mv_otg_disable(mvotg);
 670
 671         usb_remove_phy(&mvotg->phy);
 672
 673         return 0;
 674 }
 675
 676 static int mv_otg_probe(struct platform_device *pdev)
 677 {
 678         struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
 679         struct mv_otg *mvotg;
 680         struct usb_otg *otg;
 681         struct resource *r;
 682         int retval = 0, i;
 683
 684         if (pdata == NULL) {
 685                 dev_err(&pdev->dev, "failed to get platform data\n");
 686                 return -ENODEV;
 687         }
 688
 689         mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
 690         if (!mvotg) {
 691                 dev_err(&pdev->dev, "failed to allocate memory!\n");
 692                 return -ENOMEM;
 693         }
 694
 695         otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
 696         if (!otg)
 697                 return -ENOMEM;
 698
 699         platform_set_drvdata(pdev, mvotg);
 700
 701         mvotg->pdev = pdev;
 702         mvotg->pdata = pdata;
 703
 704         mvotg->clk = devm_clk_get(&pdev->dev, NULL);
 705         if (IS_ERR(mvotg->clk))
 706                 return PTR_ERR(mvotg->clk);
 707
 708         mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
 709         if (!mvotg->qwork) {
 710                 dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
 711                 return -ENOMEM;
 712         }
 713
 714         INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
 715
 716         /* OTG common part */
 717         mvotg->pdev = pdev;
 718         mvotg->phy.dev = &pdev->dev;
 719         mvotg->phy.otg = otg;
 720         mvotg->phy.label = driver_name;
 721         mvotg->phy.state = OTG_STATE_UNDEFINED;
 722
 723         otg->phy = &mvotg->phy;
 724         otg->set_host = mv_otg_set_host;
 725         otg->set_peripheral = mv_otg_set_peripheral;
 726         otg->set_vbus = mv_otg_set_vbus;
 727
 728         for (i = 0; i < OTG_TIMER_NUM; i++)
 729                 init_timer(&mvotg->otg_ctrl.timer[i]);
 730
 731         r = platform_get_resource_byname(mvotg->pdev,
 732                                          IORESOURCE_MEM, "phyregs");
 733         if (r == NULL) {
 734                 dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
 735                 retval = -ENODEV;
 736                 goto err_destroy_workqueue;
 737         }
 738
 739         mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 740         if (mvotg->phy_regs == NULL) {
 741                 dev_err(&pdev->dev, "failed to map phy I/O memory\n");
 742                 retval = -EFAULT;
 743                 goto err_destroy_workqueue;
 744         }
 745
 746         r = platform_get_resource_byname(mvotg->pdev,
 747                                          IORESOURCE_MEM, "capregs");
 748         if (r == NULL) {
 749                 dev_err(&pdev->dev, "no I/O memory resource defined\n");
 750                 retval = -ENODEV;
 751                 goto err_destroy_workqueue;
 752         }
 753
 754         mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 755         if (mvotg->cap_regs == NULL) {
 756                 dev_err(&pdev->dev, "failed to map I/O memory\n");
 757                 retval = -EFAULT;
 758                 goto err_destroy_workqueue;
 759         }
 760
 761         /* we will acces controller register, so enable the udc controller */
 762         retval = mv_otg_enable_internal(mvotg);
 763         if (retval) {
 764                 dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
 765                 goto err_destroy_workqueue;
 766         }
 767
 768         mvotg->op_regs =
 769                 (struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
 770                         + (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
 771
 772         if (pdata->id) {
 773                 retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
 774                                                 NULL, mv_otg_inputs_irq,
 775                                                 IRQF_ONESHOT, "id", mvotg);
 776                 if (retval) {
 777                         dev_info(&pdev->dev,
 778                                  "Failed to request irq for ID\n");
 779                         pdata->id = NULL;
 780                 }
 781         }
 782
 783         if (pdata->vbus) {
 784                 mvotg->clock_gating = 1;
 785                 retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
 786                                                 NULL, mv_otg_inputs_irq,
 787                                                 IRQF_ONESHOT, "vbus", mvotg);
 788                 if (retval) {
 789                         dev_info(&pdev->dev,
 790                                  "Failed to request irq for VBUS, "
 791                                  "disable clock gating\n");
 792                         mvotg->clock_gating = 0;
 793                         pdata->vbus = NULL;
 794                 }
 795         }
 796
 797         if (pdata->disable_otg_clock_gating)
 798                 mvotg->clock_gating = 0;
 799
 800         mv_otg_reset(mvotg);
 801         mv_otg_init_irq(mvotg);
 802
 803         r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
 804         if (r == NULL) {
 805                 dev_err(&pdev->dev, "no IRQ resource defined\n");
 806                 retval = -ENODEV;
 807                 goto err_disable_clk;
 808         }
 809
 810         mvotg->irq = r->start;
 811         if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
 812                         driver_name, mvotg)) {
 813                 dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
 814                         mvotg->irq);
 815                 mvotg->irq = 0;
 816                 retval = -ENODEV;
 817                 goto err_disable_clk;
 818         }
 819
 820         retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
 821         if (retval < 0) {
 822                 dev_err(&pdev->dev, "can't register transceiver, %d\n",
 823                         retval);
 824                 goto err_disable_clk;
 825         }
 826
 827         retval = sysfs_create_group(&pdev->dev.kobj, &inputs_attr_group);
 828         if (retval < 0) {
 829                 dev_dbg(&pdev->dev,
 830                         "Can't register sysfs attr group: %d\n", retval);
 831                 goto err_remove_phy;
 832         }
 833
 834         spin_lock_init(&mvotg->wq_lock);
 835         if (spin_trylock(&mvotg->wq_lock)) {
 836                 mv_otg_run_state_machine(mvotg, 2 * HZ);
 837                 spin_unlock(&mvotg->wq_lock);
 838         }
 839
 840         dev_info(&pdev->dev,
 841                  "successful probe OTG device %s clock gating.\n",
 842                  mvotg->clock_gating ? "with" : "without");
 843
 844         return 0;
 845
 846 err_remove_phy:
 847         usb_remove_phy(&mvotg->phy);
 848 err_disable_clk:
 849         mv_otg_disable_internal(mvotg);
 850 err_destroy_workqueue:
 851         flush_workqueue(mvotg->qwork);
 852         destroy_workqueue(mvotg->qwork);
 853
 854         return retval;
 855 }
 856
 857 #ifdef CONFIG_PM
 858 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
 859 {
 860         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 861
 862         if (mvotg->phy.state != OTG_STATE_B_IDLE) {
 863                 dev_info(&pdev->dev,
 864                          "OTG state is not B_IDLE, it is %d!\n",
 865                          mvotg->phy.state);
 866                 return -EAGAIN;
 867         }
 868
 869         if (!mvotg->clock_gating)
 870                 mv_otg_disable_internal(mvotg);
 871
 872         return 0;
 873 }
 874
 875 static int mv_otg_resume(struct platform_device *pdev)
 876 {
 877         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 878         u32 otgsc;
 879
 880         if (!mvotg->clock_gating) {
 881                 mv_otg_enable_internal(mvotg);
 882
 883                 otgsc = readl(&mvotg->op_regs->otgsc);
 884                 otgsc |= mvotg->irq_en;
 885                 writel(otgsc, &mvotg->op_regs->otgsc);
 886
 887                 if (spin_trylock(&mvotg->wq_lock)) {
 888                         mv_otg_run_state_machine(mvotg, 0);
 889                         spin_unlock(&mvotg->wq_lock);
 890                 }
 891         }
 892         return 0;
 893 }
 894 #endif
 895
 896 static struct platform_driver mv_otg_driver = {
 897         .probe = mv_otg_probe,
 898         .remove = mv_otg_remove,
 899         .driver = {
 900                    .owner = THIS_MODULE,
 901                    .name = driver_name,
 902                    },
 903 #ifdef CONFIG_PM
 904         .suspend = mv_otg_suspend,
 905         .resume = mv_otg_resume,
 906 #endif
 907 };
 908 module_platform_driver(mv_otg_driver);