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

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Copyright (C) 2011 Marvell International Ltd. All rights reserved.
   4  * Author: Chao Xie <chao.xie@marvell.com>
   5  *         Neil Zhang <zhangwm@marvell.com>
   6  */
   7
   8 #include <linux/module.h>
   9 #include <linux/kernel.h>
  10 #include <linux/io.h>
  11 #include <linux/uaccess.h>
  12 #include <linux/device.h>
  13 #include <linux/proc_fs.h>
  14 #include <linux/clk.h>
  15 #include <linux/workqueue.h>
  16 #include <linux/platform_device.h>
  17
  18 #include <linux/usb.h>
  19 #include <linux/usb/ch9.h>
  20 #include <linux/usb/otg.h>
  21 #include <linux/usb/gadget.h>
  22 #include <linux/usb/hcd.h>
  23 #include <linux/platform_data/mv_usb.h>
  24
  25 #include "phy-mv-usb.h"
  26
  27 #define DRIVER_DESC     "Marvell USB OTG transceiver driver"
  28
  29 MODULE_DESCRIPTION(DRIVER_DESC);
  30 MODULE_LICENSE("GPL");
  31
  32 static const char driver_name[] = "mv-otg";
  33
  34 static char *state_string[] = {
  35         "undefined",
  36         "b_idle",
  37         "b_srp_init",
  38         "b_peripheral",
  39         "b_wait_acon",
  40         "b_host",
  41         "a_idle",
  42         "a_wait_vrise",
  43         "a_wait_bcon",
  44         "a_host",
  45         "a_suspend",
  46         "a_peripheral",
  47         "a_wait_vfall",
  48         "a_vbus_err"
  49 };
  50
  51 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
  52 {
  53         struct mv_otg *mvotg = container_of(otg->usb_phy, struct mv_otg, phy);
  54         if (mvotg->pdata->set_vbus == NULL)
  55                 return -ENODEV;
  56
  57         return mvotg->pdata->set_vbus(on);
  58 }
  59
  60 static int mv_otg_set_host(struct usb_otg *otg,
  61                            struct usb_bus *host)
  62 {
  63         otg->host = host;
  64
  65         return 0;
  66 }
  67
  68 static int mv_otg_set_peripheral(struct usb_otg *otg,
  69                                  struct usb_gadget *gadget)
  70 {
  71         otg->gadget = gadget;
  72
  73         return 0;
  74 }
  75
  76 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
  77                                      unsigned long delay)
  78 {
  79         dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
  80         if (!mvotg->qwork)
  81                 return;
  82
  83         queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
  84 }
  85
  86 static void mv_otg_timer_await_bcon(struct timer_list *t)
  87 {
  88         struct mv_otg *mvotg = from_timer(mvotg, t,
  89                                           otg_ctrl.timer[A_WAIT_BCON_TIMER]);
  90
  91         mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
  92
  93         dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
  94
  95         if (spin_trylock(&mvotg->wq_lock)) {
  96                 mv_otg_run_state_machine(mvotg, 0);
  97                 spin_unlock(&mvotg->wq_lock);
  98         }
  99 }
 100
 101 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
 102 {
 103         struct timer_list *timer;
 104
 105         if (id >= OTG_TIMER_NUM)
 106                 return -EINVAL;
 107
 108         timer = &mvotg->otg_ctrl.timer[id];
 109
 110         if (timer_pending(timer))
 111                 del_timer(timer);
 112
 113         return 0;
 114 }
 115
 116 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
 117                             unsigned long interval)
 118 {
 119         struct timer_list *timer;
 120
 121         if (id >= OTG_TIMER_NUM)
 122                 return -EINVAL;
 123
 124         timer = &mvotg->otg_ctrl.timer[id];
 125         if (timer_pending(timer)) {
 126                 dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
 127                 return -EBUSY;
 128         }
 129
 130         timer->expires = jiffies + interval;
 131         add_timer(timer);
 132
 133         return 0;
 134 }
 135
 136 static int mv_otg_reset(struct mv_otg *mvotg)
 137 {
 138         unsigned int loops;
 139         u32 tmp;
 140
 141         /* Stop the controller */
 142         tmp = readl(&mvotg->op_regs->usbcmd);
 143         tmp &= ~USBCMD_RUN_STOP;
 144         writel(tmp, &mvotg->op_regs->usbcmd);
 145
 146         /* Reset the controller to get default values */
 147         writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
 148
 149         loops = 500;
 150         while (readl(&mvotg->op_regs->usbcmd) & USBCMD_CTRL_RESET) {
 151                 if (loops == 0) {
 152                         dev_err(&mvotg->pdev->dev,
 153                                 "Wait for RESET completed TIMEOUT\n");
 154                         return -ETIMEDOUT;
 155                 }
 156                 loops--;
 157                 udelay(20);
 158         }
 159
 160         writel(0x0, &mvotg->op_regs->usbintr);
 161         tmp = readl(&mvotg->op_regs->usbsts);
 162         writel(tmp, &mvotg->op_regs->usbsts);
 163
 164         return 0;
 165 }
 166
 167 static void mv_otg_init_irq(struct mv_otg *mvotg)
 168 {
 169         u32 otgsc;
 170
 171         mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
 172             | OTGSC_INTR_A_VBUS_VALID;
 173         mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
 174             | OTGSC_INTSTS_A_VBUS_VALID;
 175
 176         if (mvotg->pdata->vbus == NULL) {
 177                 mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
 178                     | OTGSC_INTR_B_SESSION_END;
 179                 mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
 180                     | OTGSC_INTSTS_B_SESSION_END;
 181         }
 182
 183         if (mvotg->pdata->id == NULL) {
 184                 mvotg->irq_en |= OTGSC_INTR_USB_ID;
 185                 mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
 186         }
 187
 188         otgsc = readl(&mvotg->op_regs->otgsc);
 189         otgsc |= mvotg->irq_en;
 190         writel(otgsc, &mvotg->op_regs->otgsc);
 191 }
 192
 193 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
 194 {
 195 #ifdef CONFIG_USB
 196         struct usb_otg *otg = mvotg->phy.otg;
 197         struct usb_hcd *hcd;
 198
 199         if (!otg->host)
 200                 return;
 201
 202         dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
 203
 204         hcd = bus_to_hcd(otg->host);
 205
 206         if (on) {
 207                 usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
 208                 device_wakeup_enable(hcd->self.controller);
 209         } else {
 210                 usb_remove_hcd(hcd);
 211         }
 212 #endif /* CONFIG_USB */
 213 }
 214
 215 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
 216 {
 217         struct usb_otg *otg = mvotg->phy.otg;
 218
 219         if (!otg->gadget)
 220                 return;
 221
 222         dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
 223
 224         if (on)
 225                 usb_gadget_vbus_connect(otg->gadget);
 226         else
 227                 usb_gadget_vbus_disconnect(otg->gadget);
 228 }
 229
 230 static void otg_clock_enable(struct mv_otg *mvotg)
 231 {
 232         clk_prepare_enable(mvotg->clk);
 233 }
 234
 235 static void otg_clock_disable(struct mv_otg *mvotg)
 236 {
 237         clk_disable_unprepare(mvotg->clk);
 238 }
 239
 240 static int mv_otg_enable_internal(struct mv_otg *mvotg)
 241 {
 242         int retval = 0;
 243
 244         if (mvotg->active)
 245                 return 0;
 246
 247         dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
 248
 249         otg_clock_enable(mvotg);
 250         if (mvotg->pdata->phy_init) {
 251                 retval = mvotg->pdata->phy_init(mvotg->phy_regs);
 252                 if (retval) {
 253                         dev_err(&mvotg->pdev->dev,
 254                                 "init phy error %d\n", retval);
 255                         otg_clock_disable(mvotg);
 256                         return retval;
 257                 }
 258         }
 259         mvotg->active = 1;
 260
 261         return 0;
 262
 263 }
 264
 265 static int mv_otg_enable(struct mv_otg *mvotg)
 266 {
 267         if (mvotg->clock_gating)
 268                 return mv_otg_enable_internal(mvotg);
 269
 270         return 0;
 271 }
 272
 273 static void mv_otg_disable_internal(struct mv_otg *mvotg)
 274 {
 275         if (mvotg->active) {
 276                 dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
 277                 if (mvotg->pdata->phy_deinit)
 278                         mvotg->pdata->phy_deinit(mvotg->phy_regs);
 279                 otg_clock_disable(mvotg);
 280                 mvotg->active = 0;
 281         }
 282 }
 283
 284 static void mv_otg_disable(struct mv_otg *mvotg)
 285 {
 286         if (mvotg->clock_gating)
 287                 mv_otg_disable_internal(mvotg);
 288 }
 289
 290 static void mv_otg_update_inputs(struct mv_otg *mvotg)
 291 {
 292         struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
 293         u32 otgsc;
 294
 295         otgsc = readl(&mvotg->op_regs->otgsc);
 296
 297         if (mvotg->pdata->vbus) {
 298                 if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
 299                         otg_ctrl->b_sess_vld = 1;
 300                         otg_ctrl->b_sess_end = 0;
 301                 } else {
 302                         otg_ctrl->b_sess_vld = 0;
 303                         otg_ctrl->b_sess_end = 1;
 304                 }
 305         } else {
 306                 otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
 307                 otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
 308         }
 309
 310         if (mvotg->pdata->id)
 311                 otg_ctrl->id = !!mvotg->pdata->id->poll();
 312         else
 313                 otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
 314
 315         if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
 316                 otg_ctrl->a_bus_req = 1;
 317
 318         otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
 319         otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
 320
 321         dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
 322         dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
 323         dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
 324         dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
 325         dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
 326         dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
 327 }
 328
 329 static void mv_otg_update_state(struct mv_otg *mvotg)
 330 {
 331         struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
 332         int old_state = mvotg->phy.otg->state;
 333
 334         switch (old_state) {
 335         case OTG_STATE_UNDEFINED:
 336                 mvotg->phy.otg->state = OTG_STATE_B_IDLE;
 337                 /* FALL THROUGH */
 338         case OTG_STATE_B_IDLE:
 339                 if (otg_ctrl->id == 0)
 340                         mvotg->phy.otg->state = OTG_STATE_A_IDLE;
 341                 else if (otg_ctrl->b_sess_vld)
 342                         mvotg->phy.otg->state = OTG_STATE_B_PERIPHERAL;
 343                 break;
 344         case OTG_STATE_B_PERIPHERAL:
 345                 if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
 346                         mvotg->phy.otg->state = OTG_STATE_B_IDLE;
 347                 break;
 348         case OTG_STATE_A_IDLE:
 349                 if (otg_ctrl->id)
 350                         mvotg->phy.otg->state = OTG_STATE_B_IDLE;
 351                 else if (!(otg_ctrl->a_bus_drop) &&
 352                          (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
 353                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_VRISE;
 354                 break;
 355         case OTG_STATE_A_WAIT_VRISE:
 356                 if (otg_ctrl->a_vbus_vld)
 357                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
 358                 break;
 359         case OTG_STATE_A_WAIT_BCON:
 360                 if (otg_ctrl->id || otg_ctrl->a_bus_drop
 361                     || otg_ctrl->a_wait_bcon_timeout) {
 362                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 363                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 364                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
 365                         otg_ctrl->a_bus_req = 0;
 366                 } else if (!otg_ctrl->a_vbus_vld) {
 367                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 368                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 369                         mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
 370                 } else if (otg_ctrl->b_conn) {
 371                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 372                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 373                         mvotg->phy.otg->state = OTG_STATE_A_HOST;
 374                 }
 375                 break;
 376         case OTG_STATE_A_HOST:
 377                 if (otg_ctrl->id || !otg_ctrl->b_conn
 378                     || otg_ctrl->a_bus_drop)
 379                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
 380                 else if (!otg_ctrl->a_vbus_vld)
 381                         mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
 382                 break;
 383         case OTG_STATE_A_WAIT_VFALL:
 384                 if (otg_ctrl->id
 385                     || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
 386                     || otg_ctrl->a_bus_req)
 387                         mvotg->phy.otg->state = OTG_STATE_A_IDLE;
 388                 break;
 389         case OTG_STATE_A_VBUS_ERR:
 390                 if (otg_ctrl->id || otg_ctrl->a_clr_err
 391                     || otg_ctrl->a_bus_drop) {
 392                         otg_ctrl->a_clr_err = 0;
 393                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
 394                 }
 395                 break;
 396         default:
 397                 break;
 398         }
 399 }
 400
 401 static void mv_otg_work(struct work_struct *work)
 402 {
 403         struct mv_otg *mvotg;
 404         struct usb_phy *phy;
 405         struct usb_otg *otg;
 406         int old_state;
 407
 408         mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
 409
 410 run:
 411         /* work queue is single thread, or we need spin_lock to protect */
 412         phy = &mvotg->phy;
 413         otg = mvotg->phy.otg;
 414         old_state = otg->state;
 415
 416         if (!mvotg->active)
 417                 return;
 418
 419         mv_otg_update_inputs(mvotg);
 420         mv_otg_update_state(mvotg);
 421
 422         if (old_state != mvotg->phy.otg->state) {
 423                 dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
 424                          state_string[old_state],
 425                          state_string[mvotg->phy.otg->state]);
 426
 427                 switch (mvotg->phy.otg->state) {
 428                 case OTG_STATE_B_IDLE:
 429                         otg->default_a = 0;
 430                         if (old_state == OTG_STATE_B_PERIPHERAL)
 431                                 mv_otg_start_periphrals(mvotg, 0);
 432                         mv_otg_reset(mvotg);
 433                         mv_otg_disable(mvotg);
 434                         usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
 435                         break;
 436                 case OTG_STATE_B_PERIPHERAL:
 437                         mv_otg_enable(mvotg);
 438                         mv_otg_start_periphrals(mvotg, 1);
 439                         usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
 440                         break;
 441                 case OTG_STATE_A_IDLE:
 442                         otg->default_a = 1;
 443                         mv_otg_enable(mvotg);
 444                         if (old_state == OTG_STATE_A_WAIT_VFALL)
 445                                 mv_otg_start_host(mvotg, 0);
 446                         mv_otg_reset(mvotg);
 447                         break;
 448                 case OTG_STATE_A_WAIT_VRISE:
 449                         mv_otg_set_vbus(otg, 1);
 450                         break;
 451                 case OTG_STATE_A_WAIT_BCON:
 452                         if (old_state != OTG_STATE_A_HOST)
 453                                 mv_otg_start_host(mvotg, 1);
 454                         mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
 455                                          T_A_WAIT_BCON);
 456                         /*
 457                          * Now, we directly enter A_HOST. So set b_conn = 1
 458                          * here. In fact, it need host driver to notify us.
 459                          */
 460                         mvotg->otg_ctrl.b_conn = 1;
 461                         break;
 462                 case OTG_STATE_A_HOST:
 463                         break;
 464                 case OTG_STATE_A_WAIT_VFALL:
 465                         /*
 466                          * Now, we has exited A_HOST. So set b_conn = 0
 467                          * here. In fact, it need host driver to notify us.
 468                          */
 469                         mvotg->otg_ctrl.b_conn = 0;
 470                         mv_otg_set_vbus(otg, 0);
 471                         break;
 472                 case OTG_STATE_A_VBUS_ERR:
 473                         break;
 474                 default:
 475                         break;
 476                 }
 477                 goto run;
 478         }
 479 }
 480
 481 static irqreturn_t mv_otg_irq(int irq, void *dev)
 482 {
 483         struct mv_otg *mvotg = dev;
 484         u32 otgsc;
 485
 486         otgsc = readl(&mvotg->op_regs->otgsc);
 487         writel(otgsc, &mvotg->op_regs->otgsc);
 488
 489         /*
 490          * if we have vbus, then the vbus detection for B-device
 491          * will be done by mv_otg_inputs_irq().
 492          */
 493         if (mvotg->pdata->vbus)
 494                 if ((otgsc & OTGSC_STS_USB_ID) &&
 495                     !(otgsc & OTGSC_INTSTS_USB_ID))
 496                         return IRQ_NONE;
 497
 498         if ((otgsc & mvotg->irq_status) == 0)
 499                 return IRQ_NONE;
 500
 501         mv_otg_run_state_machine(mvotg, 0);
 502
 503         return IRQ_HANDLED;
 504 }
 505
 506 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
 507 {
 508         struct mv_otg *mvotg = dev;
 509
 510         /* The clock may disabled at this time */
 511         if (!mvotg->active) {
 512                 mv_otg_enable(mvotg);
 513                 mv_otg_init_irq(mvotg);
 514         }
 515
 516         mv_otg_run_state_machine(mvotg, 0);
 517
 518         return IRQ_HANDLED;
 519 }
 520
 521 static ssize_t
 522 a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
 523 {
 524         struct mv_otg *mvotg = dev_get_drvdata(dev);
 525         return scnprintf(buf, PAGE_SIZE, "%d\n",
 526                          mvotg->otg_ctrl.a_bus_req);
 527 }
 528
 529 static ssize_t
 530 a_bus_req_store(struct device *dev, struct device_attribute *attr,
 531               const char *buf, size_t count)
 532 {
 533         struct mv_otg *mvotg = dev_get_drvdata(dev);
 534
 535         if (count > 2)
 536                 return -1;
 537
 538         /* We will use this interface to change to A device */
 539         if (mvotg->phy.otg->state != OTG_STATE_B_IDLE
 540             && mvotg->phy.otg->state != OTG_STATE_A_IDLE)
 541                 return -1;
 542
 543         /* The clock may disabled and we need to set irq for ID detected */
 544         mv_otg_enable(mvotg);
 545         mv_otg_init_irq(mvotg);
 546
 547         if (buf[0] == '1') {
 548                 mvotg->otg_ctrl.a_bus_req = 1;
 549                 mvotg->otg_ctrl.a_bus_drop = 0;
 550                 dev_dbg(&mvotg->pdev->dev,
 551                         "User request: a_bus_req = 1\n");
 552
 553                 if (spin_trylock(&mvotg->wq_lock)) {
 554                         mv_otg_run_state_machine(mvotg, 0);
 555                         spin_unlock(&mvotg->wq_lock);
 556                 }
 557         }
 558
 559         return count;
 560 }
 561
 562 static DEVICE_ATTR_RW(a_bus_req);
 563
 564 static ssize_t
 565 a_clr_err_store(struct device *dev, struct device_attribute *attr,
 566               const char *buf, size_t count)
 567 {
 568         struct mv_otg *mvotg = dev_get_drvdata(dev);
 569         if (!mvotg->phy.otg->default_a)
 570                 return -1;
 571
 572         if (count > 2)
 573                 return -1;
 574
 575         if (buf[0] == '1') {
 576                 mvotg->otg_ctrl.a_clr_err = 1;
 577                 dev_dbg(&mvotg->pdev->dev,
 578                         "User request: a_clr_err = 1\n");
 579         }
 580
 581         if (spin_trylock(&mvotg->wq_lock)) {
 582                 mv_otg_run_state_machine(mvotg, 0);
 583                 spin_unlock(&mvotg->wq_lock);
 584         }
 585
 586         return count;
 587 }
 588
 589 static DEVICE_ATTR_WO(a_clr_err);
 590
 591 static ssize_t
 592 a_bus_drop_show(struct device *dev, struct device_attribute *attr,
 593                char *buf)
 594 {
 595         struct mv_otg *mvotg = dev_get_drvdata(dev);
 596         return scnprintf(buf, PAGE_SIZE, "%d\n",
 597                          mvotg->otg_ctrl.a_bus_drop);
 598 }
 599
 600 static ssize_t
 601 a_bus_drop_store(struct device *dev, struct device_attribute *attr,
 602                const char *buf, size_t count)
 603 {
 604         struct mv_otg *mvotg = dev_get_drvdata(dev);
 605         if (!mvotg->phy.otg->default_a)
 606                 return -1;
 607
 608         if (count > 2)
 609                 return -1;
 610
 611         if (buf[0] == '0') {
 612                 mvotg->otg_ctrl.a_bus_drop = 0;
 613                 dev_dbg(&mvotg->pdev->dev,
 614                         "User request: a_bus_drop = 0\n");
 615         } else if (buf[0] == '1') {
 616                 mvotg->otg_ctrl.a_bus_drop = 1;
 617                 mvotg->otg_ctrl.a_bus_req = 0;
 618                 dev_dbg(&mvotg->pdev->dev,
 619                         "User request: a_bus_drop = 1\n");
 620                 dev_dbg(&mvotg->pdev->dev,
 621                         "User request: and a_bus_req = 0\n");
 622         }
 623
 624         if (spin_trylock(&mvotg->wq_lock)) {
 625                 mv_otg_run_state_machine(mvotg, 0);
 626                 spin_unlock(&mvotg->wq_lock);
 627         }
 628
 629         return count;
 630 }
 631
 632 static DEVICE_ATTR_RW(a_bus_drop);
 633
 634 static struct attribute *inputs_attrs[] = {
 635         &dev_attr_a_bus_req.attr,
 636         &dev_attr_a_clr_err.attr,
 637         &dev_attr_a_bus_drop.attr,
 638         NULL,
 639 };
 640
 641 static const struct attribute_group inputs_attr_group = {
 642         .name = "inputs",
 643         .attrs = inputs_attrs,
 644 };
 645
 646 static int mv_otg_remove(struct platform_device *pdev)
 647 {
 648         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 649
 650         sysfs_remove_group(&mvotg->pdev->dev.kobj, &inputs_attr_group);
 651
 652         if (mvotg->qwork) {
 653                 flush_workqueue(mvotg->qwork);
 654                 destroy_workqueue(mvotg->qwork);
 655         }
 656
 657         mv_otg_disable(mvotg);
 658
 659         usb_remove_phy(&mvotg->phy);
 660
 661         return 0;
 662 }
 663
 664 static int mv_otg_probe(struct platform_device *pdev)
 665 {
 666         struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
 667         struct mv_otg *mvotg;
 668         struct usb_otg *otg;
 669         struct resource *r;
 670         int retval = 0, i;
 671
 672         if (pdata == NULL) {
 673                 dev_err(&pdev->dev, "failed to get platform data\n");
 674                 return -ENODEV;
 675         }
 676
 677         mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
 678         if (!mvotg)
 679                 return -ENOMEM;
 680
 681         otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
 682         if (!otg)
 683                 return -ENOMEM;
 684
 685         platform_set_drvdata(pdev, mvotg);
 686
 687         mvotg->pdev = pdev;
 688         mvotg->pdata = pdata;
 689
 690         mvotg->clk = devm_clk_get(&pdev->dev, NULL);
 691         if (IS_ERR(mvotg->clk))
 692                 return PTR_ERR(mvotg->clk);
 693
 694         mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
 695         if (!mvotg->qwork) {
 696                 dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
 697                 return -ENOMEM;
 698         }
 699
 700         INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
 701
 702         /* OTG common part */
 703         mvotg->pdev = pdev;
 704         mvotg->phy.dev = &pdev->dev;
 705         mvotg->phy.otg = otg;
 706         mvotg->phy.label = driver_name;
 707
 708         otg->state = OTG_STATE_UNDEFINED;
 709         otg->usb_phy = &mvotg->phy;
 710         otg->set_host = mv_otg_set_host;
 711         otg->set_peripheral = mv_otg_set_peripheral;
 712         otg->set_vbus = mv_otg_set_vbus;
 713
 714         for (i = 0; i < OTG_TIMER_NUM; i++)
 715                 timer_setup(&mvotg->otg_ctrl.timer[i],
 716                             mv_otg_timer_await_bcon, 0);
 717
 718         r = platform_get_resource_byname(mvotg->pdev,
 719                                          IORESOURCE_MEM, "phyregs");
 720         if (r == NULL) {
 721                 dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
 722                 retval = -ENODEV;
 723                 goto err_destroy_workqueue;
 724         }
 725
 726         mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 727         if (mvotg->phy_regs == NULL) {
 728                 dev_err(&pdev->dev, "failed to map phy I/O memory\n");
 729                 retval = -EFAULT;
 730                 goto err_destroy_workqueue;
 731         }
 732
 733         r = platform_get_resource_byname(mvotg->pdev,
 734                                          IORESOURCE_MEM, "capregs");
 735         if (r == NULL) {
 736                 dev_err(&pdev->dev, "no I/O memory resource defined\n");
 737                 retval = -ENODEV;
 738                 goto err_destroy_workqueue;
 739         }
 740
 741         mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 742         if (mvotg->cap_regs == NULL) {
 743                 dev_err(&pdev->dev, "failed to map I/O memory\n");
 744                 retval = -EFAULT;
 745                 goto err_destroy_workqueue;
 746         }
 747
 748         /* we will acces controller register, so enable the udc controller */
 749         retval = mv_otg_enable_internal(mvotg);
 750         if (retval) {
 751                 dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
 752                 goto err_destroy_workqueue;
 753         }
 754
 755         mvotg->op_regs =
 756                 (struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
 757                         + (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
 758
 759         if (pdata->id) {
 760                 retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
 761                                                 NULL, mv_otg_inputs_irq,
 762                                                 IRQF_ONESHOT, "id", mvotg);
 763                 if (retval) {
 764                         dev_info(&pdev->dev,
 765                                  "Failed to request irq for ID\n");
 766                         pdata->id = NULL;
 767                 }
 768         }
 769
 770         if (pdata->vbus) {
 771                 mvotg->clock_gating = 1;
 772                 retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
 773                                                 NULL, mv_otg_inputs_irq,
 774                                                 IRQF_ONESHOT, "vbus", mvotg);
 775                 if (retval) {
 776                         dev_info(&pdev->dev,
 777                                  "Failed to request irq for VBUS, "
 778                                  "disable clock gating\n");
 779                         mvotg->clock_gating = 0;
 780                         pdata->vbus = NULL;
 781                 }
 782         }
 783
 784         if (pdata->disable_otg_clock_gating)
 785                 mvotg->clock_gating = 0;
 786
 787         mv_otg_reset(mvotg);
 788         mv_otg_init_irq(mvotg);
 789
 790         r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
 791         if (r == NULL) {
 792                 dev_err(&pdev->dev, "no IRQ resource defined\n");
 793                 retval = -ENODEV;
 794                 goto err_disable_clk;
 795         }
 796
 797         mvotg->irq = r->start;
 798         if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
 799                         driver_name, mvotg)) {
 800                 dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
 801                         mvotg->irq);
 802                 mvotg->irq = 0;
 803                 retval = -ENODEV;
 804                 goto err_disable_clk;
 805         }
 806
 807         retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
 808         if (retval < 0) {
 809                 dev_err(&pdev->dev, "can't register transceiver, %d\n",
 810                         retval);
 811                 goto err_disable_clk;
 812         }
 813
 814         retval = sysfs_create_group(&pdev->dev.kobj, &inputs_attr_group);
 815         if (retval < 0) {
 816                 dev_dbg(&pdev->dev,
 817                         "Can't register sysfs attr group: %d\n", retval);
 818                 goto err_remove_phy;
 819         }
 820
 821         spin_lock_init(&mvotg->wq_lock);
 822         if (spin_trylock(&mvotg->wq_lock)) {
 823                 mv_otg_run_state_machine(mvotg, 2 * HZ);
 824                 spin_unlock(&mvotg->wq_lock);
 825         }
 826
 827         dev_info(&pdev->dev,
 828                  "successful probe OTG device %s clock gating.\n",
 829                  mvotg->clock_gating ? "with" : "without");
 830
 831         return 0;
 832
 833 err_remove_phy:
 834         usb_remove_phy(&mvotg->phy);
 835 err_disable_clk:
 836         mv_otg_disable_internal(mvotg);
 837 err_destroy_workqueue:
 838         flush_workqueue(mvotg->qwork);
 839         destroy_workqueue(mvotg->qwork);
 840
 841         return retval;
 842 }
 843
 844 #ifdef CONFIG_PM
 845 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
 846 {
 847         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 848
 849         if (mvotg->phy.otg->state != OTG_STATE_B_IDLE) {
 850                 dev_info(&pdev->dev,
 851                          "OTG state is not B_IDLE, it is %d!\n",
 852                          mvotg->phy.otg->state);
 853                 return -EAGAIN;
 854         }
 855
 856         if (!mvotg->clock_gating)
 857                 mv_otg_disable_internal(mvotg);
 858
 859         return 0;
 860 }
 861
 862 static int mv_otg_resume(struct platform_device *pdev)
 863 {
 864         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 865         u32 otgsc;
 866
 867         if (!mvotg->clock_gating) {
 868                 mv_otg_enable_internal(mvotg);
 869
 870                 otgsc = readl(&mvotg->op_regs->otgsc);
 871                 otgsc |= mvotg->irq_en;
 872                 writel(otgsc, &mvotg->op_regs->otgsc);
 873
 874                 if (spin_trylock(&mvotg->wq_lock)) {
 875                         mv_otg_run_state_machine(mvotg, 0);
 876                         spin_unlock(&mvotg->wq_lock);
 877                 }
 878         }
 879         return 0;
 880 }
 881 #endif
 882
 883 static struct platform_driver mv_otg_driver = {
 884         .probe = mv_otg_probe,
 885         .remove = mv_otg_remove,
 886         .driver = {
 887                    .name = driver_name,
 888                    },
 889 #ifdef CONFIG_PM
 890         .suspend = mv_otg_suspend,
 891         .resume = mv_otg_resume,
 892 #endif
 893 };
 894 module_platform_driver(mv_otg_driver);