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/iopoll.h>
  12 #include <linux/uaccess.h>
  13 #include <linux/device.h>
  14 #include <linux/proc_fs.h>
  15 #include <linux/clk.h>
  16 #include <linux/workqueue.h>
  17 #include <linux/platform_device.h>
  18
  19 #include <linux/usb.h>
  20 #include <linux/usb/ch9.h>
  21 #include <linux/usb/otg.h>
  22 #include <linux/usb/gadget.h>
  23 #include <linux/usb/hcd.h>
  24 #include <linux/platform_data/mv_usb.h>
  25
  26 #include "phy-mv-usb.h"
  27
  28 #define DRIVER_DESC     "Marvell USB OTG transceiver driver"
  29
  30 MODULE_DESCRIPTION(DRIVER_DESC);
  31 MODULE_LICENSE("GPL");
  32
  33 static const char driver_name[] = "mv-otg";
  34
  35 static char *state_string[] = {
  36         "undefined",
  37         "b_idle",
  38         "b_srp_init",
  39         "b_peripheral",
  40         "b_wait_acon",
  41         "b_host",
  42         "a_idle",
  43         "a_wait_vrise",
  44         "a_wait_bcon",
  45         "a_host",
  46         "a_suspend",
  47         "a_peripheral",
  48         "a_wait_vfall",
  49         "a_vbus_err"
  50 };
  51
  52 static int mv_otg_set_vbus(struct usb_otg *otg, bool on)
  53 {
  54         struct mv_otg *mvotg = container_of(otg->usb_phy, struct mv_otg, phy);
  55         if (mvotg->pdata->set_vbus == NULL)
  56                 return -ENODEV;
  57
  58         return mvotg->pdata->set_vbus(on);
  59 }
  60
  61 static int mv_otg_set_host(struct usb_otg *otg,
  62                            struct usb_bus *host)
  63 {
  64         otg->host = host;
  65
  66         return 0;
  67 }
  68
  69 static int mv_otg_set_peripheral(struct usb_otg *otg,
  70                                  struct usb_gadget *gadget)
  71 {
  72         otg->gadget = gadget;
  73
  74         return 0;
  75 }
  76
  77 static void mv_otg_run_state_machine(struct mv_otg *mvotg,
  78                                      unsigned long delay)
  79 {
  80         dev_dbg(&mvotg->pdev->dev, "transceiver is updated\n");
  81         if (!mvotg->qwork)
  82                 return;
  83
  84         queue_delayed_work(mvotg->qwork, &mvotg->work, delay);
  85 }
  86
  87 static void mv_otg_timer_await_bcon(struct timer_list *t)
  88 {
  89         struct mv_otg *mvotg = from_timer(mvotg, t,
  90                                           otg_ctrl.timer[A_WAIT_BCON_TIMER]);
  91
  92         mvotg->otg_ctrl.a_wait_bcon_timeout = 1;
  93
  94         dev_info(&mvotg->pdev->dev, "B Device No Response!\n");
  95
  96         if (spin_trylock(&mvotg->wq_lock)) {
  97                 mv_otg_run_state_machine(mvotg, 0);
  98                 spin_unlock(&mvotg->wq_lock);
  99         }
 100 }
 101
 102 static int mv_otg_cancel_timer(struct mv_otg *mvotg, unsigned int id)
 103 {
 104         struct timer_list *timer;
 105
 106         if (id >= OTG_TIMER_NUM)
 107                 return -EINVAL;
 108
 109         timer = &mvotg->otg_ctrl.timer[id];
 110
 111         if (timer_pending(timer))
 112                 del_timer(timer);
 113
 114         return 0;
 115 }
 116
 117 static int mv_otg_set_timer(struct mv_otg *mvotg, unsigned int id,
 118                             unsigned long interval)
 119 {
 120         struct timer_list *timer;
 121
 122         if (id >= OTG_TIMER_NUM)
 123                 return -EINVAL;
 124
 125         timer = &mvotg->otg_ctrl.timer[id];
 126         if (timer_pending(timer)) {
 127                 dev_err(&mvotg->pdev->dev, "Timer%d is already running\n", id);
 128                 return -EBUSY;
 129         }
 130
 131         timer->expires = jiffies + interval;
 132         add_timer(timer);
 133
 134         return 0;
 135 }
 136
 137 static int mv_otg_reset(struct mv_otg *mvotg)
 138 {
 139         u32 tmp;
 140         int ret;
 141
 142         /* Stop the controller */
 143         tmp = readl(&mvotg->op_regs->usbcmd);
 144         tmp &= ~USBCMD_RUN_STOP;
 145         writel(tmp, &mvotg->op_regs->usbcmd);
 146
 147         /* Reset the controller to get default values */
 148         writel(USBCMD_CTRL_RESET, &mvotg->op_regs->usbcmd);
 149
 150         ret = readl_poll_timeout_atomic(&mvotg->op_regs->usbcmd, tmp,
 151                                 (tmp & USBCMD_CTRL_RESET), 10, 10000);
 152         if (ret < 0) {
 153                 dev_err(&mvotg->pdev->dev,
 154                         "Wait for RESET completed TIMEOUT\n");
 155                 return ret;
 156         }
 157
 158         writel(0x0, &mvotg->op_regs->usbintr);
 159         tmp = readl(&mvotg->op_regs->usbsts);
 160         writel(tmp, &mvotg->op_regs->usbsts);
 161
 162         return 0;
 163 }
 164
 165 static void mv_otg_init_irq(struct mv_otg *mvotg)
 166 {
 167         u32 otgsc;
 168
 169         mvotg->irq_en = OTGSC_INTR_A_SESSION_VALID
 170             | OTGSC_INTR_A_VBUS_VALID;
 171         mvotg->irq_status = OTGSC_INTSTS_A_SESSION_VALID
 172             | OTGSC_INTSTS_A_VBUS_VALID;
 173
 174         if (mvotg->pdata->vbus == NULL) {
 175                 mvotg->irq_en |= OTGSC_INTR_B_SESSION_VALID
 176                     | OTGSC_INTR_B_SESSION_END;
 177                 mvotg->irq_status |= OTGSC_INTSTS_B_SESSION_VALID
 178                     | OTGSC_INTSTS_B_SESSION_END;
 179         }
 180
 181         if (mvotg->pdata->id == NULL) {
 182                 mvotg->irq_en |= OTGSC_INTR_USB_ID;
 183                 mvotg->irq_status |= OTGSC_INTSTS_USB_ID;
 184         }
 185
 186         otgsc = readl(&mvotg->op_regs->otgsc);
 187         otgsc |= mvotg->irq_en;
 188         writel(otgsc, &mvotg->op_regs->otgsc);
 189 }
 190
 191 static void mv_otg_start_host(struct mv_otg *mvotg, int on)
 192 {
 193 #ifdef CONFIG_USB
 194         struct usb_otg *otg = mvotg->phy.otg;
 195         struct usb_hcd *hcd;
 196
 197         if (!otg->host)
 198                 return;
 199
 200         dev_info(&mvotg->pdev->dev, "%s host\n", on ? "start" : "stop");
 201
 202         hcd = bus_to_hcd(otg->host);
 203
 204         if (on) {
 205                 usb_add_hcd(hcd, hcd->irq, IRQF_SHARED);
 206                 device_wakeup_enable(hcd->self.controller);
 207         } else {
 208                 usb_remove_hcd(hcd);
 209         }
 210 #endif /* CONFIG_USB */
 211 }
 212
 213 static void mv_otg_start_periphrals(struct mv_otg *mvotg, int on)
 214 {
 215         struct usb_otg *otg = mvotg->phy.otg;
 216
 217         if (!otg->gadget)
 218                 return;
 219
 220         dev_info(mvotg->phy.dev, "gadget %s\n", on ? "on" : "off");
 221
 222         if (on)
 223                 usb_gadget_vbus_connect(otg->gadget);
 224         else
 225                 usb_gadget_vbus_disconnect(otg->gadget);
 226 }
 227
 228 static void otg_clock_enable(struct mv_otg *mvotg)
 229 {
 230         clk_prepare_enable(mvotg->clk);
 231 }
 232
 233 static void otg_clock_disable(struct mv_otg *mvotg)
 234 {
 235         clk_disable_unprepare(mvotg->clk);
 236 }
 237
 238 static int mv_otg_enable_internal(struct mv_otg *mvotg)
 239 {
 240         int retval = 0;
 241
 242         if (mvotg->active)
 243                 return 0;
 244
 245         dev_dbg(&mvotg->pdev->dev, "otg enabled\n");
 246
 247         otg_clock_enable(mvotg);
 248         if (mvotg->pdata->phy_init) {
 249                 retval = mvotg->pdata->phy_init(mvotg->phy_regs);
 250                 if (retval) {
 251                         dev_err(&mvotg->pdev->dev,
 252                                 "init phy error %d\n", retval);
 253                         otg_clock_disable(mvotg);
 254                         return retval;
 255                 }
 256         }
 257         mvotg->active = 1;
 258
 259         return 0;
 260
 261 }
 262
 263 static int mv_otg_enable(struct mv_otg *mvotg)
 264 {
 265         if (mvotg->clock_gating)
 266                 return mv_otg_enable_internal(mvotg);
 267
 268         return 0;
 269 }
 270
 271 static void mv_otg_disable_internal(struct mv_otg *mvotg)
 272 {
 273         if (mvotg->active) {
 274                 dev_dbg(&mvotg->pdev->dev, "otg disabled\n");
 275                 if (mvotg->pdata->phy_deinit)
 276                         mvotg->pdata->phy_deinit(mvotg->phy_regs);
 277                 otg_clock_disable(mvotg);
 278                 mvotg->active = 0;
 279         }
 280 }
 281
 282 static void mv_otg_disable(struct mv_otg *mvotg)
 283 {
 284         if (mvotg->clock_gating)
 285                 mv_otg_disable_internal(mvotg);
 286 }
 287
 288 static void mv_otg_update_inputs(struct mv_otg *mvotg)
 289 {
 290         struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
 291         u32 otgsc;
 292
 293         otgsc = readl(&mvotg->op_regs->otgsc);
 294
 295         if (mvotg->pdata->vbus) {
 296                 if (mvotg->pdata->vbus->poll() == VBUS_HIGH) {
 297                         otg_ctrl->b_sess_vld = 1;
 298                         otg_ctrl->b_sess_end = 0;
 299                 } else {
 300                         otg_ctrl->b_sess_vld = 0;
 301                         otg_ctrl->b_sess_end = 1;
 302                 }
 303         } else {
 304                 otg_ctrl->b_sess_vld = !!(otgsc & OTGSC_STS_B_SESSION_VALID);
 305                 otg_ctrl->b_sess_end = !!(otgsc & OTGSC_STS_B_SESSION_END);
 306         }
 307
 308         if (mvotg->pdata->id)
 309                 otg_ctrl->id = !!mvotg->pdata->id->poll();
 310         else
 311                 otg_ctrl->id = !!(otgsc & OTGSC_STS_USB_ID);
 312
 313         if (mvotg->pdata->otg_force_a_bus_req && !otg_ctrl->id)
 314                 otg_ctrl->a_bus_req = 1;
 315
 316         otg_ctrl->a_sess_vld = !!(otgsc & OTGSC_STS_A_SESSION_VALID);
 317         otg_ctrl->a_vbus_vld = !!(otgsc & OTGSC_STS_A_VBUS_VALID);
 318
 319         dev_dbg(&mvotg->pdev->dev, "%s: ", __func__);
 320         dev_dbg(&mvotg->pdev->dev, "id %d\n", otg_ctrl->id);
 321         dev_dbg(&mvotg->pdev->dev, "b_sess_vld %d\n", otg_ctrl->b_sess_vld);
 322         dev_dbg(&mvotg->pdev->dev, "b_sess_end %d\n", otg_ctrl->b_sess_end);
 323         dev_dbg(&mvotg->pdev->dev, "a_vbus_vld %d\n", otg_ctrl->a_vbus_vld);
 324         dev_dbg(&mvotg->pdev->dev, "a_sess_vld %d\n", otg_ctrl->a_sess_vld);
 325 }
 326
 327 static void mv_otg_update_state(struct mv_otg *mvotg)
 328 {
 329         struct mv_otg_ctrl *otg_ctrl = &mvotg->otg_ctrl;
 330         int old_state = mvotg->phy.otg->state;
 331
 332         switch (old_state) {
 333         case OTG_STATE_UNDEFINED:
 334                 mvotg->phy.otg->state = OTG_STATE_B_IDLE;
 335                 fallthrough;
 336         case OTG_STATE_B_IDLE:
 337                 if (otg_ctrl->id == 0)
 338                         mvotg->phy.otg->state = OTG_STATE_A_IDLE;
 339                 else if (otg_ctrl->b_sess_vld)
 340                         mvotg->phy.otg->state = OTG_STATE_B_PERIPHERAL;
 341                 break;
 342         case OTG_STATE_B_PERIPHERAL:
 343                 if (!otg_ctrl->b_sess_vld || otg_ctrl->id == 0)
 344                         mvotg->phy.otg->state = OTG_STATE_B_IDLE;
 345                 break;
 346         case OTG_STATE_A_IDLE:
 347                 if (otg_ctrl->id)
 348                         mvotg->phy.otg->state = OTG_STATE_B_IDLE;
 349                 else if (!(otg_ctrl->a_bus_drop) &&
 350                          (otg_ctrl->a_bus_req || otg_ctrl->a_srp_det))
 351                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_VRISE;
 352                 break;
 353         case OTG_STATE_A_WAIT_VRISE:
 354                 if (otg_ctrl->a_vbus_vld)
 355                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
 356                 break;
 357         case OTG_STATE_A_WAIT_BCON:
 358                 if (otg_ctrl->id || otg_ctrl->a_bus_drop
 359                     || otg_ctrl->a_wait_bcon_timeout) {
 360                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 361                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 362                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
 363                         otg_ctrl->a_bus_req = 0;
 364                 } else if (!otg_ctrl->a_vbus_vld) {
 365                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 366                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 367                         mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
 368                 } else if (otg_ctrl->b_conn) {
 369                         mv_otg_cancel_timer(mvotg, A_WAIT_BCON_TIMER);
 370                         mvotg->otg_ctrl.a_wait_bcon_timeout = 0;
 371                         mvotg->phy.otg->state = OTG_STATE_A_HOST;
 372                 }
 373                 break;
 374         case OTG_STATE_A_HOST:
 375                 if (otg_ctrl->id || !otg_ctrl->b_conn
 376                     || otg_ctrl->a_bus_drop)
 377                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_BCON;
 378                 else if (!otg_ctrl->a_vbus_vld)
 379                         mvotg->phy.otg->state = OTG_STATE_A_VBUS_ERR;
 380                 break;
 381         case OTG_STATE_A_WAIT_VFALL:
 382                 if (otg_ctrl->id
 383                     || (!otg_ctrl->b_conn && otg_ctrl->a_sess_vld)
 384                     || otg_ctrl->a_bus_req)
 385                         mvotg->phy.otg->state = OTG_STATE_A_IDLE;
 386                 break;
 387         case OTG_STATE_A_VBUS_ERR:
 388                 if (otg_ctrl->id || otg_ctrl->a_clr_err
 389                     || otg_ctrl->a_bus_drop) {
 390                         otg_ctrl->a_clr_err = 0;
 391                         mvotg->phy.otg->state = OTG_STATE_A_WAIT_VFALL;
 392                 }
 393                 break;
 394         default:
 395                 break;
 396         }
 397 }
 398
 399 static void mv_otg_work(struct work_struct *work)
 400 {
 401         struct mv_otg *mvotg;
 402         struct usb_otg *otg;
 403         int old_state;
 404
 405         mvotg = container_of(to_delayed_work(work), struct mv_otg, work);
 406
 407 run:
 408         /* work queue is single thread, or we need spin_lock to protect */
 409         otg = mvotg->phy.otg;
 410         old_state = otg->state;
 411
 412         if (!mvotg->active)
 413                 return;
 414
 415         mv_otg_update_inputs(mvotg);
 416         mv_otg_update_state(mvotg);
 417
 418         if (old_state != mvotg->phy.otg->state) {
 419                 dev_info(&mvotg->pdev->dev, "change from state %s to %s\n",
 420                          state_string[old_state],
 421                          state_string[mvotg->phy.otg->state]);
 422
 423                 switch (mvotg->phy.otg->state) {
 424                 case OTG_STATE_B_IDLE:
 425                         otg->default_a = 0;
 426                         if (old_state == OTG_STATE_B_PERIPHERAL)
 427                                 mv_otg_start_periphrals(mvotg, 0);
 428                         mv_otg_reset(mvotg);
 429                         mv_otg_disable(mvotg);
 430                         usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
 431                         break;
 432                 case OTG_STATE_B_PERIPHERAL:
 433                         mv_otg_enable(mvotg);
 434                         mv_otg_start_periphrals(mvotg, 1);
 435                         usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
 436                         break;
 437                 case OTG_STATE_A_IDLE:
 438                         otg->default_a = 1;
 439                         mv_otg_enable(mvotg);
 440                         if (old_state == OTG_STATE_A_WAIT_VFALL)
 441                                 mv_otg_start_host(mvotg, 0);
 442                         mv_otg_reset(mvotg);
 443                         break;
 444                 case OTG_STATE_A_WAIT_VRISE:
 445                         mv_otg_set_vbus(otg, 1);
 446                         break;
 447                 case OTG_STATE_A_WAIT_BCON:
 448                         if (old_state != OTG_STATE_A_HOST)
 449                                 mv_otg_start_host(mvotg, 1);
 450                         mv_otg_set_timer(mvotg, A_WAIT_BCON_TIMER,
 451                                          T_A_WAIT_BCON);
 452                         /*
 453                          * Now, we directly enter A_HOST. So set b_conn = 1
 454                          * here. In fact, it need host driver to notify us.
 455                          */
 456                         mvotg->otg_ctrl.b_conn = 1;
 457                         break;
 458                 case OTG_STATE_A_HOST:
 459                         break;
 460                 case OTG_STATE_A_WAIT_VFALL:
 461                         /*
 462                          * Now, we has exited A_HOST. So set b_conn = 0
 463                          * here. In fact, it need host driver to notify us.
 464                          */
 465                         mvotg->otg_ctrl.b_conn = 0;
 466                         mv_otg_set_vbus(otg, 0);
 467                         break;
 468                 case OTG_STATE_A_VBUS_ERR:
 469                         break;
 470                 default:
 471                         break;
 472                 }
 473                 goto run;
 474         }
 475 }
 476
 477 static irqreturn_t mv_otg_irq(int irq, void *dev)
 478 {
 479         struct mv_otg *mvotg = dev;
 480         u32 otgsc;
 481
 482         otgsc = readl(&mvotg->op_regs->otgsc);
 483         writel(otgsc, &mvotg->op_regs->otgsc);
 484
 485         /*
 486          * if we have vbus, then the vbus detection for B-device
 487          * will be done by mv_otg_inputs_irq().
 488          */
 489         if (mvotg->pdata->vbus)
 490                 if ((otgsc & OTGSC_STS_USB_ID) &&
 491                     !(otgsc & OTGSC_INTSTS_USB_ID))
 492                         return IRQ_NONE;
 493
 494         if ((otgsc & mvotg->irq_status) == 0)
 495                 return IRQ_NONE;
 496
 497         mv_otg_run_state_machine(mvotg, 0);
 498
 499         return IRQ_HANDLED;
 500 }
 501
 502 static irqreturn_t mv_otg_inputs_irq(int irq, void *dev)
 503 {
 504         struct mv_otg *mvotg = dev;
 505
 506         /* The clock may disabled at this time */
 507         if (!mvotg->active) {
 508                 mv_otg_enable(mvotg);
 509                 mv_otg_init_irq(mvotg);
 510         }
 511
 512         mv_otg_run_state_machine(mvotg, 0);
 513
 514         return IRQ_HANDLED;
 515 }
 516
 517 static ssize_t
 518 a_bus_req_show(struct device *dev, struct device_attribute *attr, char *buf)
 519 {
 520         struct mv_otg *mvotg = dev_get_drvdata(dev);
 521         return scnprintf(buf, PAGE_SIZE, "%d\n",
 522                          mvotg->otg_ctrl.a_bus_req);
 523 }
 524
 525 static ssize_t
 526 a_bus_req_store(struct device *dev, struct device_attribute *attr,
 527               const char *buf, size_t count)
 528 {
 529         struct mv_otg *mvotg = dev_get_drvdata(dev);
 530
 531         if (count > 2)
 532                 return -1;
 533
 534         /* We will use this interface to change to A device */
 535         if (mvotg->phy.otg->state != OTG_STATE_B_IDLE
 536             && mvotg->phy.otg->state != OTG_STATE_A_IDLE)
 537                 return -1;
 538
 539         /* The clock may disabled and we need to set irq for ID detected */
 540         mv_otg_enable(mvotg);
 541         mv_otg_init_irq(mvotg);
 542
 543         if (buf[0] == '1') {
 544                 mvotg->otg_ctrl.a_bus_req = 1;
 545                 mvotg->otg_ctrl.a_bus_drop = 0;
 546                 dev_dbg(&mvotg->pdev->dev,
 547                         "User request: a_bus_req = 1\n");
 548
 549                 if (spin_trylock(&mvotg->wq_lock)) {
 550                         mv_otg_run_state_machine(mvotg, 0);
 551                         spin_unlock(&mvotg->wq_lock);
 552                 }
 553         }
 554
 555         return count;
 556 }
 557
 558 static DEVICE_ATTR_RW(a_bus_req);
 559
 560 static ssize_t
 561 a_clr_err_store(struct device *dev, struct device_attribute *attr,
 562               const char *buf, size_t count)
 563 {
 564         struct mv_otg *mvotg = dev_get_drvdata(dev);
 565         if (!mvotg->phy.otg->default_a)
 566                 return -1;
 567
 568         if (count > 2)
 569                 return -1;
 570
 571         if (buf[0] == '1') {
 572                 mvotg->otg_ctrl.a_clr_err = 1;
 573                 dev_dbg(&mvotg->pdev->dev,
 574                         "User request: a_clr_err = 1\n");
 575         }
 576
 577         if (spin_trylock(&mvotg->wq_lock)) {
 578                 mv_otg_run_state_machine(mvotg, 0);
 579                 spin_unlock(&mvotg->wq_lock);
 580         }
 581
 582         return count;
 583 }
 584
 585 static DEVICE_ATTR_WO(a_clr_err);
 586
 587 static ssize_t
 588 a_bus_drop_show(struct device *dev, struct device_attribute *attr,
 589                char *buf)
 590 {
 591         struct mv_otg *mvotg = dev_get_drvdata(dev);
 592         return scnprintf(buf, PAGE_SIZE, "%d\n",
 593                          mvotg->otg_ctrl.a_bus_drop);
 594 }
 595
 596 static ssize_t
 597 a_bus_drop_store(struct device *dev, struct device_attribute *attr,
 598                const char *buf, size_t count)
 599 {
 600         struct mv_otg *mvotg = dev_get_drvdata(dev);
 601         if (!mvotg->phy.otg->default_a)
 602                 return -1;
 603
 604         if (count > 2)
 605                 return -1;
 606
 607         if (buf[0] == '0') {
 608                 mvotg->otg_ctrl.a_bus_drop = 0;
 609                 dev_dbg(&mvotg->pdev->dev,
 610                         "User request: a_bus_drop = 0\n");
 611         } else if (buf[0] == '1') {
 612                 mvotg->otg_ctrl.a_bus_drop = 1;
 613                 mvotg->otg_ctrl.a_bus_req = 0;
 614                 dev_dbg(&mvotg->pdev->dev,
 615                         "User request: a_bus_drop = 1\n");
 616                 dev_dbg(&mvotg->pdev->dev,
 617                         "User request: and a_bus_req = 0\n");
 618         }
 619
 620         if (spin_trylock(&mvotg->wq_lock)) {
 621                 mv_otg_run_state_machine(mvotg, 0);
 622                 spin_unlock(&mvotg->wq_lock);
 623         }
 624
 625         return count;
 626 }
 627
 628 static DEVICE_ATTR_RW(a_bus_drop);
 629
 630 static struct attribute *inputs_attrs[] = {
 631         &dev_attr_a_bus_req.attr,
 632         &dev_attr_a_clr_err.attr,
 633         &dev_attr_a_bus_drop.attr,
 634         NULL,
 635 };
 636
 637 static const struct attribute_group inputs_attr_group = {
 638         .name = "inputs",
 639         .attrs = inputs_attrs,
 640 };
 641
 642 static const struct attribute_group *mv_otg_groups[] = {
 643         &inputs_attr_group,
 644         NULL,
 645 };
 646
 647 static int mv_otg_remove(struct platform_device *pdev)
 648 {
 649         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 650
 651         if (mvotg->qwork) {
 652                 flush_workqueue(mvotg->qwork);
 653                 destroy_workqueue(mvotg->qwork);
 654         }
 655
 656         mv_otg_disable(mvotg);
 657
 658         usb_remove_phy(&mvotg->phy);
 659
 660         return 0;
 661 }
 662
 663 static int mv_otg_probe(struct platform_device *pdev)
 664 {
 665         struct mv_usb_platform_data *pdata = dev_get_platdata(&pdev->dev);
 666         struct mv_otg *mvotg;
 667         struct usb_otg *otg;
 668         struct resource *r;
 669         int retval = 0, i;
 670
 671         if (pdata == NULL) {
 672                 dev_err(&pdev->dev, "failed to get platform data\n");
 673                 return -ENODEV;
 674         }
 675
 676         mvotg = devm_kzalloc(&pdev->dev, sizeof(*mvotg), GFP_KERNEL);
 677         if (!mvotg)
 678                 return -ENOMEM;
 679
 680         otg = devm_kzalloc(&pdev->dev, sizeof(*otg), GFP_KERNEL);
 681         if (!otg)
 682                 return -ENOMEM;
 683
 684         platform_set_drvdata(pdev, mvotg);
 685
 686         mvotg->pdev = pdev;
 687         mvotg->pdata = pdata;
 688
 689         mvotg->clk = devm_clk_get(&pdev->dev, NULL);
 690         if (IS_ERR(mvotg->clk))
 691                 return PTR_ERR(mvotg->clk);
 692
 693         mvotg->qwork = create_singlethread_workqueue("mv_otg_queue");
 694         if (!mvotg->qwork) {
 695                 dev_dbg(&pdev->dev, "cannot create workqueue for OTG\n");
 696                 return -ENOMEM;
 697         }
 698
 699         INIT_DELAYED_WORK(&mvotg->work, mv_otg_work);
 700
 701         /* OTG common part */
 702         mvotg->pdev = pdev;
 703         mvotg->phy.dev = &pdev->dev;
 704         mvotg->phy.otg = otg;
 705         mvotg->phy.label = driver_name;
 706
 707         otg->state = OTG_STATE_UNDEFINED;
 708         otg->usb_phy = &mvotg->phy;
 709         otg->set_host = mv_otg_set_host;
 710         otg->set_peripheral = mv_otg_set_peripheral;
 711         otg->set_vbus = mv_otg_set_vbus;
 712
 713         for (i = 0; i < OTG_TIMER_NUM; i++)
 714                 timer_setup(&mvotg->otg_ctrl.timer[i],
 715                             mv_otg_timer_await_bcon, 0);
 716
 717         r = platform_get_resource_byname(mvotg->pdev,
 718                                          IORESOURCE_MEM, "phyregs");
 719         if (r == NULL) {
 720                 dev_err(&pdev->dev, "no phy I/O memory resource defined\n");
 721                 retval = -ENODEV;
 722                 goto err_destroy_workqueue;
 723         }
 724
 725         mvotg->phy_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 726         if (mvotg->phy_regs == NULL) {
 727                 dev_err(&pdev->dev, "failed to map phy I/O memory\n");
 728                 retval = -EFAULT;
 729                 goto err_destroy_workqueue;
 730         }
 731
 732         r = platform_get_resource_byname(mvotg->pdev,
 733                                          IORESOURCE_MEM, "capregs");
 734         if (r == NULL) {
 735                 dev_err(&pdev->dev, "no I/O memory resource defined\n");
 736                 retval = -ENODEV;
 737                 goto err_destroy_workqueue;
 738         }
 739
 740         mvotg->cap_regs = devm_ioremap(&pdev->dev, r->start, resource_size(r));
 741         if (mvotg->cap_regs == NULL) {
 742                 dev_err(&pdev->dev, "failed to map I/O memory\n");
 743                 retval = -EFAULT;
 744                 goto err_destroy_workqueue;
 745         }
 746
 747         /* we will acces controller register, so enable the udc controller */
 748         retval = mv_otg_enable_internal(mvotg);
 749         if (retval) {
 750                 dev_err(&pdev->dev, "mv otg enable error %d\n", retval);
 751                 goto err_destroy_workqueue;
 752         }
 753
 754         mvotg->op_regs =
 755                 (struct mv_otg_regs __iomem *) ((unsigned long) mvotg->cap_regs
 756                         + (readl(mvotg->cap_regs) & CAPLENGTH_MASK));
 757
 758         if (pdata->id) {
 759                 retval = devm_request_threaded_irq(&pdev->dev, pdata->id->irq,
 760                                                 NULL, mv_otg_inputs_irq,
 761                                                 IRQF_ONESHOT, "id", mvotg);
 762                 if (retval) {
 763                         dev_info(&pdev->dev,
 764                                  "Failed to request irq for ID\n");
 765                         pdata->id = NULL;
 766                 }
 767         }
 768
 769         if (pdata->vbus) {
 770                 mvotg->clock_gating = 1;
 771                 retval = devm_request_threaded_irq(&pdev->dev, pdata->vbus->irq,
 772                                                 NULL, mv_otg_inputs_irq,
 773                                                 IRQF_ONESHOT, "vbus", mvotg);
 774                 if (retval) {
 775                         dev_info(&pdev->dev,
 776                                  "Failed to request irq for VBUS, "
 777                                  "disable clock gating\n");
 778                         mvotg->clock_gating = 0;
 779                         pdata->vbus = NULL;
 780                 }
 781         }
 782
 783         if (pdata->disable_otg_clock_gating)
 784                 mvotg->clock_gating = 0;
 785
 786         mv_otg_reset(mvotg);
 787         mv_otg_init_irq(mvotg);
 788
 789         r = platform_get_resource(mvotg->pdev, IORESOURCE_IRQ, 0);
 790         if (r == NULL) {
 791                 dev_err(&pdev->dev, "no IRQ resource defined\n");
 792                 retval = -ENODEV;
 793                 goto err_disable_clk;
 794         }
 795
 796         mvotg->irq = r->start;
 797         if (devm_request_irq(&pdev->dev, mvotg->irq, mv_otg_irq, IRQF_SHARED,
 798                         driver_name, mvotg)) {
 799                 dev_err(&pdev->dev, "Request irq %d for OTG failed\n",
 800                         mvotg->irq);
 801                 mvotg->irq = 0;
 802                 retval = -ENODEV;
 803                 goto err_disable_clk;
 804         }
 805
 806         retval = usb_add_phy(&mvotg->phy, USB_PHY_TYPE_USB2);
 807         if (retval < 0) {
 808                 dev_err(&pdev->dev, "can't register transceiver, %d\n",
 809                         retval);
 810                 goto err_disable_clk;
 811         }
 812
 813         spin_lock_init(&mvotg->wq_lock);
 814         if (spin_trylock(&mvotg->wq_lock)) {
 815                 mv_otg_run_state_machine(mvotg, 2 * HZ);
 816                 spin_unlock(&mvotg->wq_lock);
 817         }
 818
 819         dev_info(&pdev->dev,
 820                  "successful probe OTG device %s clock gating.\n",
 821                  mvotg->clock_gating ? "with" : "without");
 822
 823         return 0;
 824
 825 err_disable_clk:
 826         mv_otg_disable_internal(mvotg);
 827 err_destroy_workqueue:
 828         flush_workqueue(mvotg->qwork);
 829         destroy_workqueue(mvotg->qwork);
 830
 831         return retval;
 832 }
 833
 834 #ifdef CONFIG_PM
 835 static int mv_otg_suspend(struct platform_device *pdev, pm_message_t state)
 836 {
 837         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 838
 839         if (mvotg->phy.otg->state != OTG_STATE_B_IDLE) {
 840                 dev_info(&pdev->dev,
 841                          "OTG state is not B_IDLE, it is %d!\n",
 842                          mvotg->phy.otg->state);
 843                 return -EAGAIN;
 844         }
 845
 846         if (!mvotg->clock_gating)
 847                 mv_otg_disable_internal(mvotg);
 848
 849         return 0;
 850 }
 851
 852 static int mv_otg_resume(struct platform_device *pdev)
 853 {
 854         struct mv_otg *mvotg = platform_get_drvdata(pdev);
 855         u32 otgsc;
 856
 857         if (!mvotg->clock_gating) {
 858                 mv_otg_enable_internal(mvotg);
 859
 860                 otgsc = readl(&mvotg->op_regs->otgsc);
 861                 otgsc |= mvotg->irq_en;
 862                 writel(otgsc, &mvotg->op_regs->otgsc);
 863
 864                 if (spin_trylock(&mvotg->wq_lock)) {
 865                         mv_otg_run_state_machine(mvotg, 0);
 866                         spin_unlock(&mvotg->wq_lock);
 867                 }
 868         }
 869         return 0;
 870 }
 871 #endif
 872
 873 static struct platform_driver mv_otg_driver = {
 874         .probe = mv_otg_probe,
 875         .remove = mv_otg_remove,
 876         .driver = {
 877                    .name = driver_name,
 878                    .dev_groups = mv_otg_groups,
 879                    },
 880 #ifdef CONFIG_PM
 881         .suspend = mv_otg_suspend,
 882         .resume = mv_otg_resume,
 883 #endif
 884 };
 885 module_platform_driver(mv_otg_driver);