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_otg *otg;
 405         int old_state;
 406
 407         mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
 408
 409 run:
 410         /* work queue is single thread, or we need spin_lock to protect */
 411         otg = mvotg->phy.otg;
 412         old_state = otg->state;
 413
 414         if (!mvotg->active)
 415                 return;
 416
 417         mv_otg_update_inputs(mvotg);
 418         mv_otg_update_state(mvotg);
 419
 420         if (old_state != mvotg->phy.otg->state) {
 421                 dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
 422                          state_string[old_state],
 423                          state_string[mvotg->phy.otg->state]);
 424
 425                 switch (mvotg->phy.otg->state) {
 426                 case OTG_STATE_B_IDLE:
 427                         otg->default_a = 0;
 428                         if (old_state == OTG_STATE_B_PERIPHERAL)
 429                                 mv_otg_start_periphrals(mvotg, 0);
 430                         mv_otg_reset(mvotg);
 431                         mv_otg_disable(mvotg);
 432                         usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
 433                         break;
 434                 case OTG_STATE_B_PERIPHERAL:
 435                         mv_otg_enable(mvotg);
 436                         mv_otg_start_periphrals(mvotg, 1);
 437                         usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
 438                         break;
 439                 case OTG_STATE_A_IDLE:
 440                         otg->default_a = 1;
 441                         mv_otg_enable(mvotg);
 442                         if (old_state == OTG_STATE_A_WAIT_VFALL)
 443                                 mv_otg_start_host(mvotg, 0);
 444                         mv_otg_reset(mvotg);
 445                         break;
 446                 case OTG_STATE_A_WAIT_VRISE:
 447                         mv_otg_set_vbus(otg, 1);
 448                         break;
 449                 case OTG_STATE_A_WAIT_BCON:
 450                         if (old_state != OTG_STATE_A_HOST)
 451                                 mv_otg_start_host(mvotg, 1);
 452                         mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
 453                                          T_A_WAIT_BCON);
 454                         /*
 455                          * Now, we directly enter A_HOST. So set b_conn = 1
 456                          * here. In fact, it need host driver to notify us.
 457                          */
 458                         mvotg->otg_ctrl.b_conn = 1;
 459                         break;
 460                 case OTG_STATE_A_HOST:
 461                         break;
 462                 case OTG_STATE_A_WAIT_VFALL:
 463                         /*
 464                          * Now, we has exited A_HOST. So set b_conn = 0
 465                          * here. In fact, it need host driver to notify us.
 466                          */
 467                         mvotg->otg_ctrl.b_conn = 0;
 468                         mv_otg_set_vbus(otg, 0);
 469                         break;
 470                 case OTG_STATE_A_VBUS_ERR:
 471                         break;
 472                 default:
 473                         break;
 474                 }
 475                 goto run;
 476         }
 477 }
 478
 479 static irqreturn_t mv_otg_irq(int irq, void *dev)
 480 {
 481         struct mv_otg *mvotg = dev;
 482         u32 otgsc;
 483
 484         otgsc = readl(&mvotg->op_regs->otgsc);
 485         writel(otgsc, &mvotg->op_regs->otgsc);
 486
 487         /*
 488          * if we have vbus, then the vbus detection for B-device
 489          * will be done by mv_otg_inputs_irq().
 490          */
 491         if (mvotg->pdata->vbus)
 492                 if ((otgsc & OTGSC_STS_USB_ID) &&
 493                     !(otgsc & OTGSC_INTSTS_USB_ID))
 494                         return IRQ_NONE;
 495
 496         if ((otgsc & mvotg->irq_status) == 0)
 497                 return IRQ_NONE;
 498
 499         mv_otg_run_state_machine(mvotg, 0);
 500
 501         return IRQ_HANDLED;
 502 }
 503
 504 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
 505 {
 506         struct mv_otg *mvotg = dev;
 507
 508         /* The clock may disabled at this time */
 509         if (!mvotg->active) {
 510                 mv_otg_enable(mvotg);
 511                 mv_otg_init_irq(mvotg);
 512         }
 513
 514         mv_otg_run_state_machine(mvotg, 0);
 515
 516         return IRQ_HANDLED;
 517 }
 518
 519 static ssize_t
 520 a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
 521 {
 522         struct mv_otg *mvotg = dev_get_drvdata(dev);
 523         return scnprintf(buf, PAGE_SIZE, "%d\n",
 524                          mvotg->otg_ctrl.a_bus_req);
 525 }
 526
 527 static ssize_t
 528 a_bus_req_store(struct device *dev, struct device_attribute *attr,
 529               const char *buf, size_t count)
 530 {
 531         struct mv_otg *mvotg = dev_get_drvdata(dev);
 532
 533         if (count > 2)
 534                 return -1;
 535
 536         /* We will use this interface to change to A device */
 537         if (mvotg->phy.otg->state != OTG_STATE_B_IDLE
 538             && mvotg->phy.otg->state != OTG_STATE_A_IDLE)
 539                 return -1;
 540
 541         /* The clock may disabled and we need to set irq for ID detected */
 542         mv_otg_enable(mvotg);
 543         mv_otg_init_irq(mvotg);
 544
 545         if (buf[0] == '1') {
 546                 mvotg->otg_ctrl.a_bus_req = 1;
 547                 mvotg->otg_ctrl.a_bus_drop = 0;
 548                 dev_dbg(&mvotg->pdev->dev,
 549                         "User request: a_bus_req = 1\n");
 550
 551                 if (spin_trylock(&mvotg->wq_lock)) {
 552                         mv_otg_run_state_machine(mvotg, 0);
 553                         spin_unlock(&mvotg->wq_lock);
 554                 }
 555         }
 556
 557         return count;
 558 }
 559
 560 static DEVICE_ATTR_RW(a_bus_req);
 561
 562 static ssize_t
 563 a_clr_err_store(struct device *dev, struct device_attribute *attr,
 564               const char *buf, size_t count)
 565 {
 566         struct mv_otg *mvotg = dev_get_drvdata(dev);
 567         if (!mvotg->phy.otg->default_a)
 568                 return -1;
 569
 570         if (count > 2)
 571                 return -1;
 572
 573         if (buf[0] == '1') {
 574                 mvotg->otg_ctrl.a_clr_err = 1;
 575                 dev_dbg(&mvotg->pdev->dev,
 576                         "User request: a_clr_err = 1\n");
 577         }
 578
 579         if (spin_trylock(&mvotg->wq_lock)) {
 580                 mv_otg_run_state_machine(mvotg, 0);
 581                 spin_unlock(&mvotg->wq_lock);
 582         }
 583
 584         return count;
 585 }
 586
 587 static DEVICE_ATTR_WO(a_clr_err);
 588
 589 static ssize_t
 590 a_bus_drop_show(struct device *dev, struct device_attribute *attr,
 591                char *buf)
 592 {
 593         struct mv_otg *mvotg = dev_get_drvdata(dev);
 594         return scnprintf(buf, PAGE_SIZE, "%d\n",
 595                          mvotg->otg_ctrl.a_bus_drop);
 596 }
 597
 598 static ssize_t
 599 a_bus_drop_store(struct device *dev, struct device_attribute *attr,
 600                const char *buf, size_t count)
 601 {
 602         struct mv_otg *mvotg = dev_get_drvdata(dev);
 603         if (!mvotg->phy.otg->default_a)
 604                 return -1;
 605
 606         if (count > 2)
 607                 return -1;
 608
 609         if (buf[0] == '0') {
 610                 mvotg->otg_ctrl.a_bus_drop = 0;
 611                 dev_dbg(&mvotg->pdev->dev,
 612                         "User request: a_bus_drop = 0\n");
 613         } else if (buf[0] == '1') {
 614                 mvotg->otg_ctrl.a_bus_drop = 1;
 615                 mvotg->otg_ctrl.a_bus_req = 0;
 616                 dev_dbg(&mvotg->pdev->dev,
 617                         "User request: a_bus_drop = 1\n");
 618                 dev_dbg(&mvotg->pdev->dev,
 619                         "User request: and a_bus_req = 0\n");
 620         }
 621
 622         if (spin_trylock(&mvotg->wq_lock)) {
 623                 mv_otg_run_state_machine(mvotg, 0);
 624                 spin_unlock(&mvotg->wq_lock);
 625         }
 626
 627         return count;
 628 }
 629
 630 static DEVICE_ATTR_RW(a_bus_drop);
 631
 632 static struct attribute *inputs_attrs[] = {
 633         &dev_attr_a_bus_req.attr,
 634         &dev_attr_a_clr_err.attr,
 635         &dev_attr_a_bus_drop.attr,
 636         NULL,
 637 };
 638
 639 static const struct attribute_group inputs_attr_group = {
 640         .name = "inputs",
 641         .attrs = inputs_attrs,
 642 };
 643
 644 static const struct attribute_group *mv_otg_groups[] = {
 645         &inputs_attr_group,
 646         NULL,
 647 };
 648
 649 static int mv_otg_remove(struct platform_device *pdev)
 650 {
 651         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 652
 653         if (mvotg->qwork) {
 654                 flush_workqueue(mvotg->qwork);
 655                 destroy_workqueue(mvotg->qwork);
 656         }
 657
 658         mv_otg_disable(mvotg);
 659
 660         usb_remove_phy(&mvotg->phy);
 661
 662         return 0;
 663 }
 664
 665 static int mv_otg_probe(struct platform_device *pdev)
 666 {
 667         struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
 668         struct mv_otg *mvotg;
 669         struct usb_otg *otg;
 670         struct resource *r;
 671         int retval = 0, i;
 672
 673         if (pdata == NULL) {
 674                 dev_err(&pdev->dev, "failed to get platform data\n");
 675                 return -ENODEV;
 676         }
 677
 678         mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
 679         if (!mvotg)
 680                 return -ENOMEM;
 681
 682         otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
 683         if (!otg)
 684                 return -ENOMEM;
 685
 686         platform_set_drvdata(pdev, mvotg);
 687
 688         mvotg->pdev = pdev;
 689         mvotg->pdata = pdata;
 690
 691         mvotg->clk = devm_clk_get(&pdev->dev, NULL);
 692         if (IS_ERR(mvotg->clk))
 693                 return PTR_ERR(mvotg->clk);
 694
 695         mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
 696         if (!mvotg->qwork) {
 697                 dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
 698                 return -ENOMEM;
 699         }
 700
 701         INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
 702
 703         /* OTG common part */
 704         mvotg->pdev = pdev;
 705         mvotg->phy.dev = &pdev->dev;
 706         mvotg->phy.otg = otg;
 707         mvotg->phy.label = driver_name;
 708
 709         otg->state = OTG_STATE_UNDEFINED;
 710         otg->usb_phy = &mvotg->phy;
 711         otg->set_host = mv_otg_set_host;
 712         otg->set_peripheral = mv_otg_set_peripheral;
 713         otg->set_vbus = mv_otg_set_vbus;
 714
 715         for (i = 0; i < OTG_TIMER_NUM; i++)
 716                 timer_setup(&mvotg->otg_ctrl.timer[i],
 717                             mv_otg_timer_await_bcon, 0);
 718
 719         r = platform_get_resource_byname(mvotg->pdev,
 720                                          IORESOURCE_MEM, "phyregs");
 721         if (r == NULL) {
 722                 dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
 723                 retval = -ENODEV;
 724                 goto err_destroy_workqueue;
 725         }
 726
 727         mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 728         if (mvotg->phy_regs == NULL) {
 729                 dev_err(&pdev->dev, "failed to map phy I/O memory\n");
 730                 retval = -EFAULT;
 731                 goto err_destroy_workqueue;
 732         }
 733
 734         r = platform_get_resource_byname(mvotg->pdev,
 735                                          IORESOURCE_MEM, "capregs");
 736         if (r == NULL) {
 737                 dev_err(&pdev->dev, "no I/O memory resource defined\n");
 738                 retval = -ENODEV;
 739                 goto err_destroy_workqueue;
 740         }
 741
 742         mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 743         if (mvotg->cap_regs == NULL) {
 744                 dev_err(&pdev->dev, "failed to map I/O memory\n");
 745                 retval = -EFAULT;
 746                 goto err_destroy_workqueue;
 747         }
 748
 749         /* we will acces controller register, so enable the udc controller */
 750         retval = mv_otg_enable_internal(mvotg);
 751         if (retval) {
 752                 dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
 753                 goto err_destroy_workqueue;
 754         }
 755
 756         mvotg->op_regs =
 757                 (struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
 758                         + (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
 759
 760         if (pdata->id) {
 761                 retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
 762                                                 NULL, mv_otg_inputs_irq,
 763                                                 IRQF_ONESHOT, "id", mvotg);
 764                 if (retval) {
 765                         dev_info(&pdev->dev,
 766                                  "Failed to request irq for ID\n");
 767                         pdata->id = NULL;
 768                 }
 769         }
 770
 771         if (pdata->vbus) {
 772                 mvotg->clock_gating = 1;
 773                 retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
 774                                                 NULL, mv_otg_inputs_irq,
 775                                                 IRQF_ONESHOT, "vbus", mvotg);
 776                 if (retval) {
 777                         dev_info(&pdev->dev,
 778                                  "Failed to request irq for VBUS, "
 779                                  "disable clock gating\n");
 780                         mvotg->clock_gating = 0;
 781                         pdata->vbus = NULL;
 782                 }
 783         }
 784
 785         if (pdata->disable_otg_clock_gating)
 786                 mvotg->clock_gating = 0;
 787
 788         mv_otg_reset(mvotg);
 789         mv_otg_init_irq(mvotg);
 790
 791         r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
 792         if (r == NULL) {
 793                 dev_err(&pdev->dev, "no IRQ resource defined\n");
 794                 retval = -ENODEV;
 795                 goto err_disable_clk;
 796         }
 797
 798         mvotg->irq = r->start;
 799         if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
 800                         driver_name, mvotg)) {
 801                 dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
 802                         mvotg->irq);
 803                 mvotg->irq = 0;
 804                 retval = -ENODEV;
 805                 goto err_disable_clk;
 806         }
 807
 808         retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
 809         if (retval < 0) {
 810                 dev_err(&pdev->dev, "can't register transceiver, %d\n",
 811                         retval);
 812                 goto err_disable_clk;
 813         }
 814
 815         spin_lock_init(&mvotg->wq_lock);
 816         if (spin_trylock(&mvotg->wq_lock)) {
 817                 mv_otg_run_state_machine(mvotg, 2 * HZ);
 818                 spin_unlock(&mvotg->wq_lock);
 819         }
 820
 821         dev_info(&pdev->dev,
 822                  "successful probe OTG device %s clock gating.\n",
 823                  mvotg->clock_gating ? "with" : "without");
 824
 825         return 0;
 826
 827 err_disable_clk:
 828         mv_otg_disable_internal(mvotg);
 829 err_destroy_workqueue:
 830         flush_workqueue(mvotg->qwork);
 831         destroy_workqueue(mvotg->qwork);
 832
 833         return retval;
 834 }
 835
 836 #ifdef CONFIG_PM
 837 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
 838 {
 839         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 840
 841         if (mvotg->phy.otg->state != OTG_STATE_B_IDLE) {
 842                 dev_info(&pdev->dev,
 843                          "OTG state is not B_IDLE, it is %d!\n",
 844                          mvotg->phy.otg->state);
 845                 return -EAGAIN;
 846         }
 847
 848         if (!mvotg->clock_gating)
 849                 mv_otg_disable_internal(mvotg);
 850
 851         return 0;
 852 }
 853
 854 static int mv_otg_resume(struct platform_device *pdev)
 855 {
 856         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 857         u32 otgsc;
 858
 859         if (!mvotg->clock_gating) {
 860                 mv_otg_enable_internal(mvotg);
 861
 862                 otgsc = readl(&mvotg->op_regs->otgsc);
 863                 otgsc |= mvotg->irq_en;
 864                 writel(otgsc, &mvotg->op_regs->otgsc);
 865
 866                 if (spin_trylock(&mvotg->wq_lock)) {
 867                         mv_otg_run_state_machine(mvotg, 0);
 868                         spin_unlock(&mvotg->wq_lock);
 869                 }
 870         }
 871         return 0;
 872 }
 873 #endif
 874
 875 static struct platform_driver mv_otg_driver = {
 876         .probe = mv_otg_probe,
 877         .remove = mv_otg_remove,
 878         .driver = {
 879                    .name = driver_name,
 880                    .dev_groups = mv_otg_groups,
 881                    },
 882 #ifdef CONFIG_PM
 883         .suspend = mv_otg_suspend,
 884         .resume = mv_otg_resume,
 885 #endif
 886 };
 887 module_platform_driver(mv_otg_driver);