root/drivers/usb/host/ehci-tegra.c

DEFINITIONS

1. tegra_reset_usb_controller
2. tegra_ehci_internal_port_reset
3. tegra_ehci_hub_control
4. free_dma_aligned_buffer
5. alloc_dma_aligned_buffer
6. tegra_ehci_map_urb_for_dma
7. tegra_ehci_unmap_urb_for_dma
8. tegra_ehci_probe
9. tegra_ehci_remove
10. tegra_ehci_hcd_shutdown
11. tegra_ehci_reset
12. ehci_tegra_init
13. ehci_tegra_cleanup

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * EHCI-compliant USB host controller driver for NVIDIA Tegra SoCs
   4  *
   5  * Copyright (C) 2010 Google, Inc.
   6  * Copyright (C) 2009 - 2013 NVIDIA Corporation
   7  */
   8 
   9 #include <linux/clk.h>
  10 #include <linux/dma-mapping.h>
  11 #include <linux/err.h>
  12 #include <linux/gpio.h>
  13 #include <linux/io.h>
  14 #include <linux/irq.h>
  15 #include <linux/module.h>
  16 #include <linux/of.h>
  17 #include <linux/of_device.h>
  18 #include <linux/of_gpio.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/pm_runtime.h>
  21 #include <linux/reset.h>
  22 #include <linux/slab.h>
  23 #include <linux/usb/ehci_def.h>
  24 #include <linux/usb/tegra_usb_phy.h>
  25 #include <linux/usb.h>
  26 #include <linux/usb/hcd.h>
  27 #include <linux/usb/otg.h>
  28 
  29 #include "ehci.h"
  30 
  31 #define PORT_WAKE_BITS (PORT_WKOC_E|PORT_WKDISC_E|PORT_WKCONN_E)
  32 
  33 #define TEGRA_USB_DMA_ALIGN 32
  34 
  35 #define DRIVER_DESC "Tegra EHCI driver"
  36 #define DRV_NAME "tegra-ehci"
  37 
  38 static struct hc_driver __read_mostly tegra_ehci_hc_driver;
  39 
  40 struct tegra_ehci_soc_config {
  41         bool has_hostpc;
  42 };
  43 
  44 struct tegra_ehci_hcd {
  45         struct tegra_usb_phy *phy;
  46         struct clk *clk;
  47         struct reset_control *rst;
  48         int port_resuming;
  49         bool needs_double_reset;
  50         enum tegra_usb_phy_port_speed port_speed;
  51 };
  52 
  53 static int tegra_reset_usb_controller(struct platform_device *pdev)
  54 {
  55         struct device_node *phy_np;
  56         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  57         struct tegra_ehci_hcd *tegra =
  58                 (struct tegra_ehci_hcd *)hcd_to_ehci(hcd)->priv;
  59         struct reset_control *rst;
  60         int err;
  61 
  62         phy_np = of_parse_phandle(pdev->dev.of_node, "nvidia,phy", 0);
  63         if (!phy_np)
  64                 return -ENOENT;
  65 
  66         /*
  67          * The 1st USB controller contains some UTMI pad registers that are
  68          * global for all the controllers on the chip. Those registers are
  69          * also cleared when reset is asserted to the 1st controller.
  70          */
  71         rst = of_reset_control_get_shared(phy_np, "utmi-pads");
  72         if (IS_ERR(rst)) {
  73                 dev_warn(&pdev->dev,
  74                          "can't get utmi-pads reset from the PHY\n");
  75                 dev_warn(&pdev->dev,
  76                          "continuing, but please update your DT\n");
  77         } else {
  78                 /*
  79                  * PHY driver performs UTMI-pads reset in a case of
  80                  * non-legacy DT.
  81                  */
  82                 reset_control_put(rst);
  83         }
  84 
  85         of_node_put(phy_np);
  86 
  87         /* reset control is shared, hence initialize it first */
  88         err = reset_control_deassert(tegra->rst);
  89         if (err)
  90                 return err;
  91 
  92         err = reset_control_assert(tegra->rst);
  93         if (err)
  94                 return err;
  95 
  96         udelay(1);
  97 
  98         err = reset_control_deassert(tegra->rst);
  99         if (err)
 100                 return err;
 101 
 102         return 0;
 103 }
 104 
 105 static int tegra_ehci_internal_port_reset(
 106         struct ehci_hcd *ehci,
 107         u32 __iomem     *portsc_reg
 108 )
 109 {
 110         u32             temp;
 111         unsigned long   flags;
 112         int             retval = 0;
 113         int             i, tries;
 114         u32             saved_usbintr;
 115 
 116         spin_lock_irqsave(&ehci->lock, flags);
 117         saved_usbintr = ehci_readl(ehci, &ehci->regs->intr_enable);
 118         /* disable USB interrupt */
 119         ehci_writel(ehci, 0, &ehci->regs->intr_enable);
 120         spin_unlock_irqrestore(&ehci->lock, flags);
 121 
 122         /*
 123          * Here we have to do Port Reset at most twice for
 124          * Port Enable bit to be set.
 125          */
 126         for (i = 0; i < 2; i++) {
 127                 temp = ehci_readl(ehci, portsc_reg);
 128                 temp |= PORT_RESET;
 129                 ehci_writel(ehci, temp, portsc_reg);
 130                 mdelay(10);
 131                 temp &= ~PORT_RESET;
 132                 ehci_writel(ehci, temp, portsc_reg);
 133                 mdelay(1);
 134                 tries = 100;
 135                 do {
 136                         mdelay(1);
 137                         /*
 138                          * Up to this point, Port Enable bit is
 139                          * expected to be set after 2 ms waiting.
 140                          * USB1 usually takes extra 45 ms, for safety,
 141                          * we take 100 ms as timeout.
 142                          */
 143                         temp = ehci_readl(ehci, portsc_reg);
 144                 } while (!(temp & PORT_PE) && tries--);
 145                 if (temp & PORT_PE)
 146                         break;
 147         }
 148         if (i == 2)
 149                 retval = -ETIMEDOUT;
 150 
 151         /*
 152          * Clear Connect Status Change bit if it's set.
 153          * We can't clear PORT_PEC. It will also cause PORT_PE to be cleared.
 154          */
 155         if (temp & PORT_CSC)
 156                 ehci_writel(ehci, PORT_CSC, portsc_reg);
 157 
 158         /*
 159          * Write to clear any interrupt status bits that might be set
 160          * during port reset.
 161          */
 162         temp = ehci_readl(ehci, &ehci->regs->status);
 163         ehci_writel(ehci, temp, &ehci->regs->status);
 164 
 165         /* restore original interrupt enable bits */
 166         ehci_writel(ehci, saved_usbintr, &ehci->regs->intr_enable);
 167         return retval;
 168 }
 169 
 170 static int tegra_ehci_hub_control(
 171         struct usb_hcd  *hcd,
 172         u16             typeReq,
 173         u16             wValue,
 174         u16             wIndex,
 175         char            *buf,
 176         u16             wLength
 177 )
 178 {
 179         struct ehci_hcd *ehci = hcd_to_ehci(hcd);
 180         struct tegra_ehci_hcd *tegra = (struct tegra_ehci_hcd *)ehci->priv;
 181         u32 __iomem     *status_reg;
 182         u32             temp;
 183         unsigned long   flags;
 184         int             retval = 0;
 185 
 186         status_reg = &ehci->regs->port_status[(wIndex & 0xff) - 1];
 187 
 188         spin_lock_irqsave(&ehci->lock, flags);
 189 
 190         if (typeReq == GetPortStatus) {
 191                 temp = ehci_readl(ehci, status_reg);
 192                 if (tegra->port_resuming && !(temp & PORT_SUSPEND)) {
 193                         /* Resume completed, re-enable disconnect detection */
 194                         tegra->port_resuming = 0;
 195                         tegra_usb_phy_postresume(hcd->usb_phy);
 196                 }
 197         }
 198 
 199         else if (typeReq == SetPortFeature && wValue == USB_PORT_FEAT_SUSPEND) {
 200                 temp = ehci_readl(ehci, status_reg);
 201                 if ((temp & PORT_PE) == 0 || (temp & PORT_RESET) != 0) {
 202                         retval = -EPIPE;
 203                         goto done;
 204                 }
 205 
 206                 temp &= ~(PORT_RWC_BITS | PORT_WKCONN_E);
 207                 temp |= PORT_WKDISC_E | PORT_WKOC_E;
 208                 ehci_writel(ehci, temp | PORT_SUSPEND, status_reg);
 209 
 210                 /*
 211                  * If a transaction is in progress, there may be a delay in
 212                  * suspending the port. Poll until the port is suspended.
 213                  */
 214                 if (ehci_handshake(ehci, status_reg, PORT_SUSPEND,
 215                                                 PORT_SUSPEND, 5000))
 216                         pr_err("%s: timeout waiting for SUSPEND\n", __func__);
 217 
 218                 set_bit((wIndex & 0xff) - 1, &ehci->suspended_ports);
 219                 goto done;
 220         }
 221 
 222         /* For USB1 port we need to issue Port Reset twice internally */
 223         if (tegra->needs_double_reset &&
 224            (typeReq == SetPortFeature && wValue == USB_PORT_FEAT_RESET)) {
 225                 spin_unlock_irqrestore(&ehci->lock, flags);
 226                 return tegra_ehci_internal_port_reset(ehci, status_reg);
 227         }
 228 
 229         /*
 230          * Tegra host controller will time the resume operation to clear the bit
 231          * when the port control state switches to HS or FS Idle. This behavior
 232          * is different from EHCI where the host controller driver is required
 233          * to set this bit to a zero after the resume duration is timed in the
 234          * driver.
 235          */
 236         else if (typeReq == ClearPortFeature &&
 237                                         wValue == USB_PORT_FEAT_SUSPEND) {
 238                 temp = ehci_readl(ehci, status_reg);
 239                 if ((temp & PORT_RESET) || !(temp & PORT_PE)) {
 240                         retval = -EPIPE;
 241                         goto done;
 242                 }
 243 
 244                 if (!(temp & PORT_SUSPEND))
 245                         goto done;
 246 
 247                 /* Disable disconnect detection during port resume */
 248                 tegra_usb_phy_preresume(hcd->usb_phy);
 249 
 250                 ehci->reset_done[wIndex-1] = jiffies + msecs_to_jiffies(25);
 251 
 252                 temp &= ~(PORT_RWC_BITS | PORT_WAKE_BITS);
 253                 /* start resume signalling */
 254                 ehci_writel(ehci, temp | PORT_RESUME, status_reg);
 255                 set_bit(wIndex-1, &ehci->resuming_ports);
 256 
 257                 spin_unlock_irqrestore(&ehci->lock, flags);
 258                 msleep(20);
 259                 spin_lock_irqsave(&ehci->lock, flags);
 260 
 261                 /* Poll until the controller clears RESUME and SUSPEND */
 262                 if (ehci_handshake(ehci, status_reg, PORT_RESUME, 0, 2000))
 263                         pr_err("%s: timeout waiting for RESUME\n", __func__);
 264                 if (ehci_handshake(ehci, status_reg, PORT_SUSPEND, 0, 2000))
 265                         pr_err("%s: timeout waiting for SUSPEND\n", __func__);
 266 
 267                 ehci->reset_done[wIndex-1] = 0;
 268                 clear_bit(wIndex-1, &ehci->resuming_ports);
 269 
 270                 tegra->port_resuming = 1;
 271                 goto done;
 272         }
 273 
 274         spin_unlock_irqrestore(&ehci->lock, flags);
 275 
 276         /* Handle the hub control events here */
 277         return ehci_hub_control(hcd, typeReq, wValue, wIndex, buf, wLength);
 278 
 279 done:
 280         spin_unlock_irqrestore(&ehci->lock, flags);
 281         return retval;
 282 }
 283 
 284 struct dma_aligned_buffer {
 285         void *kmalloc_ptr;
 286         void *old_xfer_buffer;
 287         u8 data[0];
 288 };
 289 
 290 static void free_dma_aligned_buffer(struct urb *urb)
 291 {
 292         struct dma_aligned_buffer *temp;
 293         size_t length;
 294 
 295         if (!(urb->transfer_flags & URB_ALIGNED_TEMP_BUFFER))
 296                 return;
 297 
 298         temp = container_of(urb->transfer_buffer,
 299                 struct dma_aligned_buffer, data);
 300 
 301         if (usb_urb_dir_in(urb)) {
 302                 if (usb_pipeisoc(urb->pipe))
 303                         length = urb->transfer_buffer_length;
 304                 else
 305                         length = urb->actual_length;
 306 
 307                 memcpy(temp->old_xfer_buffer, temp->data, length);
 308         }
 309         urb->transfer_buffer = temp->old_xfer_buffer;
 310         kfree(temp->kmalloc_ptr);
 311 
 312         urb->transfer_flags &= ~URB_ALIGNED_TEMP_BUFFER;
 313 }
 314 
 315 static int alloc_dma_aligned_buffer(struct urb *urb, gfp_t mem_flags)
 316 {
 317         struct dma_aligned_buffer *temp, *kmalloc_ptr;
 318         size_t kmalloc_size;
 319 
 320         if (urb->num_sgs || urb->sg ||
 321             urb->transfer_buffer_length == 0 ||
 322             !((uintptr_t)urb->transfer_buffer & (TEGRA_USB_DMA_ALIGN - 1)))
 323                 return 0;
 324 
 325         /* Allocate a buffer with enough padding for alignment */
 326         kmalloc_size = urb->transfer_buffer_length +
 327                 sizeof(struct dma_aligned_buffer) + TEGRA_USB_DMA_ALIGN - 1;
 328 
 329         kmalloc_ptr = kmalloc(kmalloc_size, mem_flags);
 330         if (!kmalloc_ptr)
 331                 return -ENOMEM;
 332 
 333         /* Position our struct dma_aligned_buffer such that data is aligned */
 334         temp = PTR_ALIGN(kmalloc_ptr + 1, TEGRA_USB_DMA_ALIGN) - 1;
 335         temp->kmalloc_ptr = kmalloc_ptr;
 336         temp->old_xfer_buffer = urb->transfer_buffer;
 337         if (usb_urb_dir_out(urb))
 338                 memcpy(temp->data, urb->transfer_buffer,
 339                        urb->transfer_buffer_length);
 340         urb->transfer_buffer = temp->data;
 341 
 342         urb->transfer_flags |= URB_ALIGNED_TEMP_BUFFER;
 343 
 344         return 0;
 345 }
 346 
 347 static int tegra_ehci_map_urb_for_dma(struct usb_hcd *hcd, struct urb *urb,
 348                                       gfp_t mem_flags)
 349 {
 350         int ret;
 351 
 352         ret = alloc_dma_aligned_buffer(urb, mem_flags);
 353         if (ret)
 354                 return ret;
 355 
 356         ret = usb_hcd_map_urb_for_dma(hcd, urb, mem_flags);
 357         if (ret)
 358                 free_dma_aligned_buffer(urb);
 359 
 360         return ret;
 361 }
 362 
 363 static void tegra_ehci_unmap_urb_for_dma(struct usb_hcd *hcd, struct urb *urb)
 364 {
 365         usb_hcd_unmap_urb_for_dma(hcd, urb);
 366         free_dma_aligned_buffer(urb);
 367 }
 368 
 369 static const struct tegra_ehci_soc_config tegra30_soc_config = {
 370         .has_hostpc = true,
 371 };
 372 
 373 static const struct tegra_ehci_soc_config tegra20_soc_config = {
 374         .has_hostpc = false,
 375 };
 376 
 377 static const struct of_device_id tegra_ehci_of_match[] = {
 378         { .compatible = "nvidia,tegra30-ehci", .data = &tegra30_soc_config },
 379         { .compatible = "nvidia,tegra20-ehci", .data = &tegra20_soc_config },
 380         { },
 381 };
 382 
 383 static int tegra_ehci_probe(struct platform_device *pdev)
 384 {
 385         const struct of_device_id *match;
 386         const struct tegra_ehci_soc_config *soc_config;
 387         struct resource *res;
 388         struct usb_hcd *hcd;
 389         struct ehci_hcd *ehci;
 390         struct tegra_ehci_hcd *tegra;
 391         int err = 0;
 392         int irq;
 393         struct usb_phy *u_phy;
 394 
 395         match = of_match_device(tegra_ehci_of_match, &pdev->dev);
 396         if (!match) {
 397                 dev_err(&pdev->dev, "Error: No device match found\n");
 398                 return -ENODEV;
 399         }
 400         soc_config = match->data;
 401 
 402         /* Right now device-tree probed devices don't get dma_mask set.
 403          * Since shared usb code relies on it, set it here for now.
 404          * Once we have dma capability bindings this can go away.
 405          */
 406         err = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 407         if (err)
 408                 return err;
 409 
 410         hcd = usb_create_hcd(&tegra_ehci_hc_driver, &pdev->dev,
 411                                         dev_name(&pdev->dev));
 412         if (!hcd) {
 413                 dev_err(&pdev->dev, "Unable to create HCD\n");
 414                 return -ENOMEM;
 415         }
 416         platform_set_drvdata(pdev, hcd);
 417         ehci = hcd_to_ehci(hcd);
 418         tegra = (struct tegra_ehci_hcd *)ehci->priv;
 419 
 420         hcd->has_tt = 1;
 421 
 422         tegra->clk = devm_clk_get(&pdev->dev, NULL);
 423         if (IS_ERR(tegra->clk)) {
 424                 dev_err(&pdev->dev, "Can't get ehci clock\n");
 425                 err = PTR_ERR(tegra->clk);
 426                 goto cleanup_hcd_create;
 427         }
 428 
 429         tegra->rst = devm_reset_control_get_shared(&pdev->dev, "usb");
 430         if (IS_ERR(tegra->rst)) {
 431                 dev_err(&pdev->dev, "Can't get ehci reset\n");
 432                 err = PTR_ERR(tegra->rst);
 433                 goto cleanup_hcd_create;
 434         }
 435 
 436         err = clk_prepare_enable(tegra->clk);
 437         if (err)
 438                 goto cleanup_hcd_create;
 439 
 440         err = tegra_reset_usb_controller(pdev);
 441         if (err) {
 442                 dev_err(&pdev->dev, "Failed to reset controller\n");
 443                 goto cleanup_clk_en;
 444         }
 445 
 446         u_phy = devm_usb_get_phy_by_phandle(&pdev->dev, "nvidia,phy", 0);
 447         if (IS_ERR(u_phy)) {
 448                 err = -EPROBE_DEFER;
 449                 goto cleanup_clk_en;
 450         }
 451         hcd->usb_phy = u_phy;
 452         hcd->skip_phy_initialization = 1;
 453 
 454         tegra->needs_double_reset = of_property_read_bool(pdev->dev.of_node,
 455                 "nvidia,needs-double-reset");
 456 
 457         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 458         hcd->regs = devm_ioremap_resource(&pdev->dev, res);
 459         if (IS_ERR(hcd->regs)) {
 460                 err = PTR_ERR(hcd->regs);
 461                 goto cleanup_clk_en;
 462         }
 463         hcd->rsrc_start = res->start;
 464         hcd->rsrc_len = resource_size(res);
 465 
 466         ehci->caps = hcd->regs + 0x100;
 467         ehci->has_hostpc = soc_config->has_hostpc;
 468 
 469         err = usb_phy_init(hcd->usb_phy);
 470         if (err) {
 471                 dev_err(&pdev->dev, "Failed to initialize phy\n");
 472                 goto cleanup_clk_en;
 473         }
 474 
 475         u_phy->otg = devm_kzalloc(&pdev->dev, sizeof(struct usb_otg),
 476                              GFP_KERNEL);
 477         if (!u_phy->otg) {
 478                 err = -ENOMEM;
 479                 goto cleanup_phy;
 480         }
 481         u_phy->otg->host = hcd_to_bus(hcd);
 482 
 483         err = usb_phy_set_suspend(hcd->usb_phy, 0);
 484         if (err) {
 485                 dev_err(&pdev->dev, "Failed to power on the phy\n");
 486                 goto cleanup_phy;
 487         }
 488 
 489         irq = platform_get_irq(pdev, 0);
 490         if (!irq) {
 491                 dev_err(&pdev->dev, "Failed to get IRQ\n");
 492                 err = -ENODEV;
 493                 goto cleanup_phy;
 494         }
 495 
 496         otg_set_host(u_phy->otg, &hcd->self);
 497 
 498         err = usb_add_hcd(hcd, irq, IRQF_SHARED);
 499         if (err) {
 500                 dev_err(&pdev->dev, "Failed to add USB HCD\n");
 501                 goto cleanup_otg_set_host;
 502         }
 503         device_wakeup_enable(hcd->self.controller);
 504 
 505         return err;
 506 
 507 cleanup_otg_set_host:
 508         otg_set_host(u_phy->otg, NULL);
 509 cleanup_phy:
 510         usb_phy_shutdown(hcd->usb_phy);
 511 cleanup_clk_en:
 512         clk_disable_unprepare(tegra->clk);
 513 cleanup_hcd_create:
 514         usb_put_hcd(hcd);
 515         return err;
 516 }
 517 
 518 static int tegra_ehci_remove(struct platform_device *pdev)
 519 {
 520         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 521         struct tegra_ehci_hcd *tegra =
 522                 (struct tegra_ehci_hcd *)hcd_to_ehci(hcd)->priv;
 523 
 524         otg_set_host(hcd->usb_phy->otg, NULL);
 525 
 526         usb_phy_shutdown(hcd->usb_phy);
 527         usb_remove_hcd(hcd);
 528 
 529         reset_control_assert(tegra->rst);
 530         udelay(1);
 531 
 532         clk_disable_unprepare(tegra->clk);
 533 
 534         usb_put_hcd(hcd);
 535 
 536         return 0;
 537 }
 538 
 539 static void tegra_ehci_hcd_shutdown(struct platform_device *pdev)
 540 {
 541         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 542 
 543         if (hcd->driver->shutdown)
 544                 hcd->driver->shutdown(hcd);
 545 }
 546 
 547 static struct platform_driver tegra_ehci_driver = {
 548         .probe          = tegra_ehci_probe,
 549         .remove         = tegra_ehci_remove,
 550         .shutdown       = tegra_ehci_hcd_shutdown,
 551         .driver         = {
 552                 .name   = DRV_NAME,
 553                 .of_match_table = tegra_ehci_of_match,
 554         }
 555 };
 556 
 557 static int tegra_ehci_reset(struct usb_hcd *hcd)
 558 {
 559         struct ehci_hcd *ehci = hcd_to_ehci(hcd);
 560         int retval;
 561         int txfifothresh;
 562 
 563         retval = ehci_setup(hcd);
 564         if (retval)
 565                 return retval;
 566 
 567         /*
 568          * We should really pull this value out of tegra_ehci_soc_config, but
 569          * to avoid needing access to it, make use of the fact that Tegra20 is
 570          * the only one so far that needs a value of 10, and Tegra20 is the
 571          * only one which doesn't set has_hostpc.
 572          */
 573         txfifothresh = ehci->has_hostpc ? 0x10 : 10;
 574         ehci_writel(ehci, txfifothresh << 16, &ehci->regs->txfill_tuning);
 575 
 576         return 0;
 577 }
 578 
 579 static const struct ehci_driver_overrides tegra_overrides __initconst = {
 580         .extra_priv_size        = sizeof(struct tegra_ehci_hcd),
 581         .reset                  = tegra_ehci_reset,
 582 };
 583 
 584 static int __init ehci_tegra_init(void)
 585 {
 586         if (usb_disabled())
 587                 return -ENODEV;
 588 
 589         pr_info(DRV_NAME ": " DRIVER_DESC "\n");
 590 
 591         ehci_init_driver(&tegra_ehci_hc_driver, &tegra_overrides);
 592 
 593         /*
 594          * The Tegra HW has some unusual quirks, which require Tegra-specific
 595          * workarounds. We override certain hc_driver functions here to
 596          * achieve that. We explicitly do not enhance ehci_driver_overrides to
 597          * allow this more easily, since this is an unusual case, and we don't
 598          * want to encourage others to override these functions by making it
 599          * too easy.
 600          */
 601 
 602         tegra_ehci_hc_driver.map_urb_for_dma = tegra_ehci_map_urb_for_dma;
 603         tegra_ehci_hc_driver.unmap_urb_for_dma = tegra_ehci_unmap_urb_for_dma;
 604         tegra_ehci_hc_driver.hub_control = tegra_ehci_hub_control;
 605 
 606         return platform_driver_register(&tegra_ehci_driver);
 607 }
 608 module_init(ehci_tegra_init);
 609 
 610 static void __exit ehci_tegra_cleanup(void)
 611 {
 612         platform_driver_unregister(&tegra_ehci_driver);
 613 }
 614 module_exit(ehci_tegra_cleanup);
 615 
 616 MODULE_DESCRIPTION(DRIVER_DESC);
 617 MODULE_LICENSE("GPL");
 618 MODULE_ALIAS("platform:" DRV_NAME);
 619 MODULE_DEVICE_TABLE(of, tegra_ehci_of_match);