drivers/usb/musb/am35x.c

   1 /*
   2  * Texas Instruments AM35x "glue layer"
   3  *
   4  * Copyright (c) 2010, by Texas Instruments
   5  *
   6  * Based on the DA8xx "glue layer" code.
   7  * Copyright (c) 2008-2009, MontaVista Software, Inc. <source@mvista.com>
   8  *
   9  * This file is part of the Inventra Controller Driver for Linux.
  10  *
  11  * The Inventra Controller Driver for Linux is free software; you
  12  * can redistribute it and/or modify it under the terms of the GNU
  13  * General Public License version 2 as published by the Free Software
  14  * Foundation.
  15  *
  16  * The Inventra Controller Driver for Linux is distributed in
  17  * the hope that it will be useful, but WITHOUT ANY WARRANTY;
  18  * without even the implied warranty of MERCHANTABILITY or
  19  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public
  20  * License for more details.
  21  *
  22  * You should have received a copy of the GNU General Public License
  23  * along with The Inventra Controller Driver for Linux ; if not,
  24  * write to the Free Software Foundation, Inc., 59 Temple Place,
  25  * Suite 330, Boston, MA  02111-1307  USA
  26  *
  27  */
  28
  29 #include <linux/init.h>
  30 #include <linux/module.h>
  31 #include <linux/clk.h>
  32 #include <linux/err.h>
  33 #include <linux/io.h>
  34 #include <linux/platform_device.h>
  35 #include <linux/dma-mapping.h>
  36 #include <linux/usb/nop-usb-xceiv.h>
  37 #include <linux/platform_data/usb-omap.h>
  38
  39 #include "musb_core.h"
  40
  41 /*
  42  * AM35x specific definitions
  43  */
  44 /* USB 2.0 OTG module registers */
  45 #define USB_REVISION_REG        0x00
  46 #define USB_CTRL_REG            0x04
  47 #define USB_STAT_REG            0x08
  48 #define USB_EMULATION_REG       0x0c
  49 /* 0x10 Reserved */
  50 #define USB_AUTOREQ_REG         0x14
  51 #define USB_SRP_FIX_TIME_REG    0x18
  52 #define USB_TEARDOWN_REG        0x1c
  53 #define EP_INTR_SRC_REG         0x20
  54 #define EP_INTR_SRC_SET_REG     0x24
  55 #define EP_INTR_SRC_CLEAR_REG   0x28
  56 #define EP_INTR_MASK_REG        0x2c
  57 #define EP_INTR_MASK_SET_REG    0x30
  58 #define EP_INTR_MASK_CLEAR_REG  0x34
  59 #define EP_INTR_SRC_MASKED_REG  0x38
  60 #define CORE_INTR_SRC_REG       0x40
  61 #define CORE_INTR_SRC_SET_REG   0x44
  62 #define CORE_INTR_SRC_CLEAR_REG 0x48
  63 #define CORE_INTR_MASK_REG      0x4c
  64 #define CORE_INTR_MASK_SET_REG  0x50
  65 #define CORE_INTR_MASK_CLEAR_REG 0x54
  66 #define CORE_INTR_SRC_MASKED_REG 0x58
  67 /* 0x5c Reserved */
  68 #define USB_END_OF_INTR_REG     0x60
  69
  70 /* Control register bits */
  71 #define AM35X_SOFT_RESET_MASK   1
  72
  73 /* USB interrupt register bits */
  74 #define AM35X_INTR_USB_SHIFT    16
  75 #define AM35X_INTR_USB_MASK     (0x1ff << AM35X_INTR_USB_SHIFT)
  76 #define AM35X_INTR_DRVVBUS      0x100
  77 #define AM35X_INTR_RX_SHIFT     16
  78 #define AM35X_INTR_TX_SHIFT     0
  79 #define AM35X_TX_EP_MASK        0xffff          /* EP0 + 15 Tx EPs */
  80 #define AM35X_RX_EP_MASK        0xfffe          /* 15 Rx EPs */
  81 #define AM35X_TX_INTR_MASK      (AM35X_TX_EP_MASK << AM35X_INTR_TX_SHIFT)
  82 #define AM35X_RX_INTR_MASK      (AM35X_RX_EP_MASK << AM35X_INTR_RX_SHIFT)
  83
  84 #define USB_MENTOR_CORE_OFFSET  0x400
  85
  86 struct am35x_glue {
  87         struct device           *dev;
  88         struct platform_device  *musb;
  89         struct clk              *phy_clk;
  90         struct clk              *clk;
  91 };
  92 #define glue_to_musb(g)         platform_get_drvdata(g->musb)
  93
  94 /*
  95  * am35x_musb_enable - enable interrupts
  96  */
  97 static void am35x_musb_enable(struct musb *musb)
  98 {
  99         void __iomem *reg_base = musb->ctrl_base;
 100         u32 epmask;
 101
 102         /* Workaround: setup IRQs through both register sets. */
 103         epmask = ((musb->epmask & AM35X_TX_EP_MASK) << AM35X_INTR_TX_SHIFT) |
 104                ((musb->epmask & AM35X_RX_EP_MASK) << AM35X_INTR_RX_SHIFT);
 105
 106         musb_writel(reg_base, EP_INTR_MASK_SET_REG, epmask);
 107         musb_writel(reg_base, CORE_INTR_MASK_SET_REG, AM35X_INTR_USB_MASK);
 108
 109         /* Force the DRVVBUS IRQ so we can start polling for ID change. */
 110         musb_writel(reg_base, CORE_INTR_SRC_SET_REG,
 111                         AM35X_INTR_DRVVBUS << AM35X_INTR_USB_SHIFT);
 112 }
 113
 114 /*
 115  * am35x_musb_disable - disable HDRC and flush interrupts
 116  */
 117 static void am35x_musb_disable(struct musb *musb)
 118 {
 119         void __iomem *reg_base = musb->ctrl_base;
 120
 121         musb_writel(reg_base, CORE_INTR_MASK_CLEAR_REG, AM35X_INTR_USB_MASK);
 122         musb_writel(reg_base, EP_INTR_MASK_CLEAR_REG,
 123                          AM35X_TX_INTR_MASK | AM35X_RX_INTR_MASK);
 124         musb_writeb(musb->mregs, MUSB_DEVCTL, 0);
 125         musb_writel(reg_base, USB_END_OF_INTR_REG, 0);
 126 }
 127
 128 #define portstate(stmt)         stmt
 129
 130 static void am35x_musb_set_vbus(struct musb *musb, int is_on)
 131 {
 132         WARN_ON(is_on && is_peripheral_active(musb));
 133 }
 134
 135 #define POLL_SECONDS    2
 136
 137 static struct timer_list otg_workaround;
 138
 139 static void otg_timer(unsigned long _musb)
 140 {
 141         struct musb             *musb = (void *)_musb;
 142         void __iomem            *mregs = musb->mregs;
 143         u8                      devctl;
 144         unsigned long           flags;
 145
 146         /*
 147          * We poll because AM35x's won't expose several OTG-critical
 148          * status change events (from the transceiver) otherwise.
 149          */
 150         devctl = musb_readb(mregs, MUSB_DEVCTL);
 151         dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
 152                 usb_otg_state_string(musb->xceiv->state));
 153
 154         spin_lock_irqsave(&musb->lock, flags);
 155         switch (musb->xceiv->state) {
 156         case OTG_STATE_A_WAIT_BCON:
 157                 devctl &= ~MUSB_DEVCTL_SESSION;
 158                 musb_writeb(musb->mregs, MUSB_DEVCTL, devctl);
 159
 160                 devctl = musb_readb(musb->mregs, MUSB_DEVCTL);
 161                 if (devctl & MUSB_DEVCTL_BDEVICE) {
 162                         musb->xceiv->state = OTG_STATE_B_IDLE;
 163                         MUSB_DEV_MODE(musb);
 164                 } else {
 165                         musb->xceiv->state = OTG_STATE_A_IDLE;
 166                         MUSB_HST_MODE(musb);
 167                 }
 168                 break;
 169         case OTG_STATE_A_WAIT_VFALL:
 170                 musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
 171                 musb_writel(musb->ctrl_base, CORE_INTR_SRC_SET_REG,
 172                             MUSB_INTR_VBUSERROR << AM35X_INTR_USB_SHIFT);
 173                 break;
 174         case OTG_STATE_B_IDLE:
 175                 devctl = musb_readb(mregs, MUSB_DEVCTL);
 176                 if (devctl & MUSB_DEVCTL_BDEVICE)
 177                         mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
 178                 else
 179                         musb->xceiv->state = OTG_STATE_A_IDLE;
 180                 break;
 181         default:
 182                 break;
 183         }
 184         spin_unlock_irqrestore(&musb->lock, flags);
 185 }
 186
 187 static void am35x_musb_try_idle(struct musb *musb, unsigned long timeout)
 188 {
 189         static unsigned long last_timer;
 190
 191         if (timeout == 0)
 192                 timeout = jiffies + msecs_to_jiffies(3);
 193
 194         /* Never idle if active, or when VBUS timeout is not set as host */
 195         if (musb->is_active || (musb->a_wait_bcon == 0 &&
 196                                 musb->xceiv->state == OTG_STATE_A_WAIT_BCON)) {
 197                 dev_dbg(musb->controller, "%s active, deleting timer\n",
 198                         usb_otg_state_string(musb->xceiv->state));
 199                 del_timer(&otg_workaround);
 200                 last_timer = jiffies;
 201                 return;
 202         }
 203
 204         if (time_after(last_timer, timeout) && timer_pending(&otg_workaround)) {
 205                 dev_dbg(musb->controller, "Longer idle timer already pending, ignoring...\n");
 206                 return;
 207         }
 208         last_timer = timeout;
 209
 210         dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
 211                 usb_otg_state_string(musb->xceiv->state),
 212                 jiffies_to_msecs(timeout - jiffies));
 213         mod_timer(&otg_workaround, timeout);
 214 }
 215
 216 static irqreturn_t am35x_musb_interrupt(int irq, void *hci)
 217 {
 218         struct musb  *musb = hci;
 219         void __iomem *reg_base = musb->ctrl_base;
 220         struct device *dev = musb->controller;
 221         struct musb_hdrc_platform_data *plat = dev->platform_data;
 222         struct omap_musb_board_data *data = plat->board_data;
 223         struct usb_otg *otg = musb->xceiv->otg;
 224         unsigned long flags;
 225         irqreturn_t ret = IRQ_NONE;
 226         u32 epintr, usbintr;
 227
 228         spin_lock_irqsave(&musb->lock, flags);
 229
 230         /* Get endpoint interrupts */
 231         epintr = musb_readl(reg_base, EP_INTR_SRC_MASKED_REG);
 232
 233         if (epintr) {
 234                 musb_writel(reg_base, EP_INTR_SRC_CLEAR_REG, epintr);
 235
 236                 musb->int_rx =
 237                         (epintr & AM35X_RX_INTR_MASK) >> AM35X_INTR_RX_SHIFT;
 238                 musb->int_tx =
 239                         (epintr & AM35X_TX_INTR_MASK) >> AM35X_INTR_TX_SHIFT;
 240         }
 241
 242         /* Get usb core interrupts */
 243         usbintr = musb_readl(reg_base, CORE_INTR_SRC_MASKED_REG);
 244         if (!usbintr && !epintr)
 245                 goto eoi;
 246
 247         if (usbintr) {
 248                 musb_writel(reg_base, CORE_INTR_SRC_CLEAR_REG, usbintr);
 249
 250                 musb->int_usb =
 251                         (usbintr & AM35X_INTR_USB_MASK) >> AM35X_INTR_USB_SHIFT;
 252         }
 253         /*
 254          * DRVVBUS IRQs are the only proxy we have (a very poor one!) for
 255          * AM35x's missing ID change IRQ.  We need an ID change IRQ to
 256          * switch appropriately between halves of the OTG state machine.
 257          * Managing DEVCTL.SESSION per Mentor docs requires that we know its
 258          * value but DEVCTL.BDEVICE is invalid without DEVCTL.SESSION set.
 259          * Also, DRVVBUS pulses for SRP (but not at 5V) ...
 260          */
 261         if (usbintr & (AM35X_INTR_DRVVBUS << AM35X_INTR_USB_SHIFT)) {
 262                 int drvvbus = musb_readl(reg_base, USB_STAT_REG);
 263                 void __iomem *mregs = musb->mregs;
 264                 u8 devctl = musb_readb(mregs, MUSB_DEVCTL);
 265                 int err;
 266
 267                 err = musb->int_usb & MUSB_INTR_VBUSERROR;
 268                 if (err) {
 269                         /*
 270                          * The Mentor core doesn't debounce VBUS as needed
 271                          * to cope with device connect current spikes. This
 272                          * means it's not uncommon for bus-powered devices
 273                          * to get VBUS errors during enumeration.
 274                          *
 275                          * This is a workaround, but newer RTL from Mentor
 276                          * seems to allow a better one: "re"-starting sessions
 277                          * without waiting for VBUS to stop registering in
 278                          * devctl.
 279                          */
 280                         musb->int_usb &= ~MUSB_INTR_VBUSERROR;
 281                         musb->xceiv->state = OTG_STATE_A_WAIT_VFALL;
 282                         mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
 283                         WARNING("VBUS error workaround (delay coming)\n");
 284                 } else if (drvvbus) {
 285                         MUSB_HST_MODE(musb);
 286                         otg->default_a = 1;
 287                         musb->xceiv->state = OTG_STATE_A_WAIT_VRISE;
 288                         portstate(musb->port1_status |= USB_PORT_STAT_POWER);
 289                         del_timer(&otg_workaround);
 290                 } else {
 291                         musb->is_active = 0;
 292                         MUSB_DEV_MODE(musb);
 293                         otg->default_a = 0;
 294                         musb->xceiv->state = OTG_STATE_B_IDLE;
 295                         portstate(musb->port1_status &= ~USB_PORT_STAT_POWER);
 296                 }
 297
 298                 /* NOTE: this must complete power-on within 100 ms. */
 299                 dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n",
 300                                 drvvbus ? "on" : "off",
 301                                 usb_otg_state_string(musb->xceiv->state),
 302                                 err ? " ERROR" : "",
 303                                 devctl);
 304                 ret = IRQ_HANDLED;
 305         }
 306
 307         /* Drop spurious RX and TX if device is disconnected */
 308         if (musb->int_usb & MUSB_INTR_DISCONNECT) {
 309                 musb->int_tx = 0;
 310                 musb->int_rx = 0;
 311         }
 312
 313         if (musb->int_tx || musb->int_rx || musb->int_usb)
 314                 ret |= musb_interrupt(musb);
 315
 316 eoi:
 317         /* EOI needs to be written for the IRQ to be re-asserted. */
 318         if (ret == IRQ_HANDLED || epintr || usbintr) {
 319                 /* clear level interrupt */
 320                 if (data->clear_irq)
 321                         data->clear_irq();
 322                 /* write EOI */
 323                 musb_writel(reg_base, USB_END_OF_INTR_REG, 0);
 324         }
 325
 326         /* Poll for ID change */
 327         if (musb->xceiv->state == OTG_STATE_B_IDLE)
 328                 mod_timer(&otg_workaround, jiffies + POLL_SECONDS * HZ);
 329
 330         spin_unlock_irqrestore(&musb->lock, flags);
 331
 332         return ret;
 333 }
 334
 335 static int am35x_musb_set_mode(struct musb *musb, u8 musb_mode)
 336 {
 337         struct device *dev = musb->controller;
 338         struct musb_hdrc_platform_data *plat = dev->platform_data;
 339         struct omap_musb_board_data *data = plat->board_data;
 340         int     retval = 0;
 341
 342         if (data->set_mode)
 343                 data->set_mode(musb_mode);
 344         else
 345                 retval = -EIO;
 346
 347         return retval;
 348 }
 349
 350 static int am35x_musb_init(struct musb *musb)
 351 {
 352         struct device *dev = musb->controller;
 353         struct musb_hdrc_platform_data *plat = dev->platform_data;
 354         struct omap_musb_board_data *data = plat->board_data;
 355         void __iomem *reg_base = musb->ctrl_base;
 356         u32 rev;
 357
 358         musb->mregs += USB_MENTOR_CORE_OFFSET;
 359
 360         /* Returns zero if e.g. not clocked */
 361         rev = musb_readl(reg_base, USB_REVISION_REG);
 362         if (!rev)
 363                 return -ENODEV;
 364
 365         usb_nop_xceiv_register();
 366         musb->xceiv = usb_get_phy(USB_PHY_TYPE_USB2);
 367         if (IS_ERR_OR_NULL(musb->xceiv))
 368                 return -EPROBE_DEFER;
 369
 370         setup_timer(&otg_workaround, otg_timer, (unsigned long) musb);
 371
 372         /* Reset the musb */
 373         if (data->reset)
 374                 data->reset();
 375
 376         /* Reset the controller */
 377         musb_writel(reg_base, USB_CTRL_REG, AM35X_SOFT_RESET_MASK);
 378
 379         /* Start the on-chip PHY and its PLL. */
 380         if (data->set_phy_power)
 381                 data->set_phy_power(1);
 382
 383         msleep(5);
 384
 385         musb->isr = am35x_musb_interrupt;
 386
 387         /* clear level interrupt */
 388         if (data->clear_irq)
 389                 data->clear_irq();
 390
 391         return 0;
 392 }
 393
 394 static int am35x_musb_exit(struct musb *musb)
 395 {
 396         struct device *dev = musb->controller;
 397         struct musb_hdrc_platform_data *plat = dev->platform_data;
 398         struct omap_musb_board_data *data = plat->board_data;
 399
 400         del_timer_sync(&otg_workaround);
 401
 402         /* Shutdown the on-chip PHY and its PLL. */
 403         if (data->set_phy_power)
 404                 data->set_phy_power(0);
 405
 406         usb_put_phy(musb->xceiv);
 407         usb_nop_xceiv_unregister();
 408
 409         return 0;
 410 }
 411
 412 /* AM35x supports only 32bit read operation */
 413 void musb_read_fifo(struct musb_hw_ep *hw_ep, u16 len, u8 *dst)
 414 {
 415         void __iomem *fifo = hw_ep->fifo;
 416         u32             val;
 417         int             i;
 418
 419         /* Read for 32bit-aligned destination address */
 420         if (likely((0x03 & (unsigned long) dst) == 0) && len >= 4) {
 421                 readsl(fifo, dst, len >> 2);
 422                 dst += len & ~0x03;
 423                 len &= 0x03;
 424         }
 425         /*
 426          * Now read the remaining 1 to 3 byte or complete length if
 427          * unaligned address.
 428          */
 429         if (len > 4) {
 430                 for (i = 0; i < (len >> 2); i++) {
 431                         *(u32 *) dst = musb_readl(fifo, 0);
 432                         dst += 4;
 433                 }
 434                 len &= 0x03;
 435         }
 436         if (len > 0) {
 437                 val = musb_readl(fifo, 0);
 438                 memcpy(dst, &val, len);
 439         }
 440 }
 441
 442 static const struct musb_platform_ops am35x_ops = {
 443         .init           = am35x_musb_init,
 444         .exit           = am35x_musb_exit,
 445
 446         .enable         = am35x_musb_enable,
 447         .disable        = am35x_musb_disable,
 448
 449         .set_mode       = am35x_musb_set_mode,
 450         .try_idle       = am35x_musb_try_idle,
 451
 452         .set_vbus       = am35x_musb_set_vbus,
 453 };
 454
 455 static u64 am35x_dmamask = DMA_BIT_MASK(32);
 456
 457 static int am35x_probe(struct platform_device *pdev)
 458 {
 459         struct musb_hdrc_platform_data  *pdata = pdev->dev.platform_data;
 460         struct platform_device          *musb;
 461         struct am35x_glue               *glue;
 462
 463         struct clk                      *phy_clk;
 464         struct clk                      *clk;
 465
 466         int                             ret = -ENOMEM;
 467
 468         glue = kzalloc(sizeof(*glue), GFP_KERNEL);
 469         if (!glue) {
 470                 dev_err(&pdev->dev, "failed to allocate glue context\n");
 471                 goto err0;
 472         }
 473
 474         musb = platform_device_alloc("musb-hdrc", PLATFORM_DEVID_AUTO);
 475         if (!musb) {
 476                 dev_err(&pdev->dev, "failed to allocate musb device\n");
 477                 goto err1;
 478         }
 479
 480         phy_clk = clk_get(&pdev->dev, "fck");
 481         if (IS_ERR(phy_clk)) {
 482                 dev_err(&pdev->dev, "failed to get PHY clock\n");
 483                 ret = PTR_ERR(phy_clk);
 484                 goto err3;
 485         }
 486
 487         clk = clk_get(&pdev->dev, "ick");
 488         if (IS_ERR(clk)) {
 489                 dev_err(&pdev->dev, "failed to get clock\n");
 490                 ret = PTR_ERR(clk);
 491                 goto err4;
 492         }
 493
 494         ret = clk_enable(phy_clk);
 495         if (ret) {
 496                 dev_err(&pdev->dev, "failed to enable PHY clock\n");
 497                 goto err5;
 498         }
 499
 500         ret = clk_enable(clk);
 501         if (ret) {
 502                 dev_err(&pdev->dev, "failed to enable clock\n");
 503                 goto err6;
 504         }
 505
 506         musb->dev.parent                = &pdev->dev;
 507         musb->dev.dma_mask              = &am35x_dmamask;
 508         musb->dev.coherent_dma_mask     = am35x_dmamask;
 509
 510         glue->dev                       = &pdev->dev;
 511         glue->musb                      = musb;
 512         glue->phy_clk                   = phy_clk;
 513         glue->clk                       = clk;
 514
 515         pdata->platform_ops             = &am35x_ops;
 516
 517         platform_set_drvdata(pdev, glue);
 518
 519         ret = platform_device_add_resources(musb, pdev->resource,
 520                         pdev->num_resources);
 521         if (ret) {
 522                 dev_err(&pdev->dev, "failed to add resources\n");
 523                 goto err7;
 524         }
 525
 526         ret = platform_device_add_data(musb, pdata, sizeof(*pdata));
 527         if (ret) {
 528                 dev_err(&pdev->dev, "failed to add platform_data\n");
 529                 goto err7;
 530         }
 531
 532         ret = platform_device_add(musb);
 533         if (ret) {
 534                 dev_err(&pdev->dev, "failed to register musb device\n");
 535                 goto err7;
 536         }
 537
 538         return 0;
 539
 540 err7:
 541         clk_disable(clk);
 542
 543 err6:
 544         clk_disable(phy_clk);
 545
 546 err5:
 547         clk_put(clk);
 548
 549 err4:
 550         clk_put(phy_clk);
 551
 552 err3:
 553         platform_device_put(musb);
 554
 555 err1:
 556         kfree(glue);
 557
 558 err0:
 559         return ret;
 560 }
 561
 562 static int am35x_remove(struct platform_device *pdev)
 563 {
 564         struct am35x_glue       *glue = platform_get_drvdata(pdev);
 565
 566         platform_device_unregister(glue->musb);
 567         clk_disable(glue->clk);
 568         clk_disable(glue->phy_clk);
 569         clk_put(glue->clk);
 570         clk_put(glue->phy_clk);
 571         kfree(glue);
 572
 573         return 0;
 574 }
 575
 576 #ifdef CONFIG_PM
 577 static int am35x_suspend(struct device *dev)
 578 {
 579         struct am35x_glue       *glue = dev_get_drvdata(dev);
 580         struct musb_hdrc_platform_data *plat = dev->platform_data;
 581         struct omap_musb_board_data *data = plat->board_data;
 582
 583         /* Shutdown the on-chip PHY and its PLL. */
 584         if (data->set_phy_power)
 585                 data->set_phy_power(0);
 586
 587         clk_disable(glue->phy_clk);
 588         clk_disable(glue->clk);
 589
 590         return 0;
 591 }
 592
 593 static int am35x_resume(struct device *dev)
 594 {
 595         struct am35x_glue       *glue = dev_get_drvdata(dev);
 596         struct musb_hdrc_platform_data *plat = dev->platform_data;
 597         struct omap_musb_board_data *data = plat->board_data;
 598         int                     ret;
 599
 600         /* Start the on-chip PHY and its PLL. */
 601         if (data->set_phy_power)
 602                 data->set_phy_power(1);
 603
 604         ret = clk_enable(glue->phy_clk);
 605         if (ret) {
 606                 dev_err(dev, "failed to enable PHY clock\n");
 607                 return ret;
 608         }
 609
 610         ret = clk_enable(glue->clk);
 611         if (ret) {
 612                 dev_err(dev, "failed to enable clock\n");
 613                 return ret;
 614         }
 615
 616         return 0;
 617 }
 618
 619 static struct dev_pm_ops am35x_pm_ops = {
 620         .suspend        = am35x_suspend,
 621         .resume         = am35x_resume,
 622 };
 623
 624 #define DEV_PM_OPS      &am35x_pm_ops
 625 #else
 626 #define DEV_PM_OPS      NULL
 627 #endif
 628
 629 static struct platform_driver am35x_driver = {
 630         .probe          = am35x_probe,
 631         .remove         = am35x_remove,
 632         .driver         = {
 633                 .name   = "musb-am35x",
 634                 .pm     = DEV_PM_OPS,
 635         },
 636 };
 637
 638 MODULE_DESCRIPTION("AM35x MUSB Glue Layer");
 639 MODULE_AUTHOR("Ajay Kumar Gupta <ajay.gupta@ti.com>");
 640 MODULE_LICENSE("GPL v2");
 641 module_platform_driver(am35x_driver);