drivers/usb/host/ohci-at91.c

   1 /*
   2  * OHCI HCD (Host Controller Driver) for USB.
   3  *
   4  *  Copyright (C) 2004 SAN People (Pty) Ltd.
   5  *  Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
   6  *
   7  * AT91 Bus Glue
   8  *
   9  * Based on fragments of 2.4 driver by Rick Bronson.
  10  * Based on ohci-omap.c
  11  *
  12  * This file is licenced under the GPL.
  13  */
  14
  15 #include <linux/clk.h>
  16 #include <linux/dma-mapping.h>
  17 #include <linux/of_platform.h>
  18 #include <linux/of_gpio.h>
  19 #include <linux/platform_device.h>
  20 #include <linux/platform_data/atmel.h>
  21 #include <linux/io.h>
  22 #include <linux/kernel.h>
  23 #include <linux/module.h>
  24 #include <linux/usb.h>
  25 #include <linux/usb/hcd.h>
  26
  27 #include <asm/gpio.h>
  28
  29 #include "ohci.h"
  30
  31 #define valid_port(index)       ((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
  32 #define at91_for_each_port(index)       \
  33                 for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
  34
  35 /* interface, function and usb clocks; sometimes also an AHB clock */
  36 static struct clk *iclk, *fclk, *uclk, *hclk;
  37 /* interface and function clocks; sometimes also an AHB clock */
  38
  39 #define DRIVER_DESC "OHCI Atmel driver"
  40
  41 static const char hcd_name[] = "ohci-atmel";
  42
  43 static struct hc_driver __read_mostly ohci_at91_hc_driver;
  44 static int clocked;
  45
  46 extern int usb_disabled(void);
  47
  48 /*-------------------------------------------------------------------------*/
  49
  50 static void at91_start_clock(void)
  51 {
  52         if (IS_ENABLED(CONFIG_COMMON_CLK)) {
  53                 clk_set_rate(uclk, 48000000);
  54                 clk_prepare_enable(uclk);
  55         }
  56         clk_prepare_enable(hclk);
  57         clk_prepare_enable(iclk);
  58         clk_prepare_enable(fclk);
  59         clocked = 1;
  60 }
  61
  62 static void at91_stop_clock(void)
  63 {
  64         clk_disable_unprepare(fclk);
  65         clk_disable_unprepare(iclk);
  66         clk_disable_unprepare(hclk);
  67         if (IS_ENABLED(CONFIG_COMMON_CLK))
  68                 clk_disable_unprepare(uclk);
  69         clocked = 0;
  70 }
  71
  72 static void at91_start_hc(struct platform_device *pdev)
  73 {
  74         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  75         struct ohci_regs __iomem *regs = hcd->regs;
  76
  77         dev_dbg(&pdev->dev, "start\n");
  78
  79         /*
  80          * Start the USB clocks.
  81          */
  82         at91_start_clock();
  83
  84         /*
  85          * The USB host controller must remain in reset.
  86          */
  87         writel(0, &regs->control);
  88 }
  89
  90 static void at91_stop_hc(struct platform_device *pdev)
  91 {
  92         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  93         struct ohci_regs __iomem *regs = hcd->regs;
  94
  95         dev_dbg(&pdev->dev, "stop\n");
  96
  97         /*
  98          * Put the USB host controller into reset.
  99          */
 100         writel(0, &regs->control);
 101
 102         /*
 103          * Stop the USB clocks.
 104          */
 105         at91_stop_clock();
 106 }
 107
 108
 109 /*-------------------------------------------------------------------------*/
 110
 111 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
 112
 113 /* configure so an HC device and id are always provided */
 114 /* always called with process context; sleeping is OK */
 115
 116
 117 /**
 118  * usb_hcd_at91_probe - initialize AT91-based HCDs
 119  * Context: !in_interrupt()
 120  *
 121  * Allocates basic resources for this USB host controller, and
 122  * then invokes the start() method for the HCD associated with it
 123  * through the hotplug entry's driver_data.
 124  */
 125 static int usb_hcd_at91_probe(const struct hc_driver *driver,
 126                         struct platform_device *pdev)
 127 {
 128         struct at91_usbh_data *board;
 129         struct ohci_hcd *ohci;
 130         int retval;
 131         struct usb_hcd *hcd = NULL;
 132         struct device *dev = &pdev->dev;
 133         struct resource *res;
 134         int irq;
 135
 136         irq = platform_get_irq(pdev, 0);
 137         if (irq < 0) {
 138                 dev_dbg(dev, "hcd probe: missing irq resource\n");
 139                 return irq;
 140         }
 141
 142         hcd = usb_create_hcd(driver, dev, "at91");
 143         if (!hcd)
 144                 return -ENOMEM;
 145
 146         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 147         hcd->regs = devm_ioremap_resource(dev, res);
 148         if (IS_ERR(hcd->regs)) {
 149                 retval = PTR_ERR(hcd->regs);
 150                 goto err;
 151         }
 152         hcd->rsrc_start = res->start;
 153         hcd->rsrc_len = resource_size(res);
 154
 155         iclk = devm_clk_get(dev, "ohci_clk");
 156         if (IS_ERR(iclk)) {
 157                 dev_err(dev, "failed to get ohci_clk\n");
 158                 retval = PTR_ERR(iclk);
 159                 goto err;
 160         }
 161         fclk = devm_clk_get(dev, "uhpck");
 162         if (IS_ERR(fclk)) {
 163                 dev_err(dev, "failed to get uhpck\n");
 164                 retval = PTR_ERR(fclk);
 165                 goto err;
 166         }
 167         hclk = devm_clk_get(dev, "hclk");
 168         if (IS_ERR(hclk)) {
 169                 dev_err(dev, "failed to get hclk\n");
 170                 retval = PTR_ERR(hclk);
 171                 goto err;
 172         }
 173         if (IS_ENABLED(CONFIG_COMMON_CLK)) {
 174                 uclk = devm_clk_get(dev, "usb_clk");
 175                 if (IS_ERR(uclk)) {
 176                         dev_err(dev, "failed to get uclk\n");
 177                         retval = PTR_ERR(uclk);
 178                         goto err;
 179                 }
 180         }
 181
 182         board = hcd->self.controller->platform_data;
 183         ohci = hcd_to_ohci(hcd);
 184         ohci->num_ports = board->ports;
 185         at91_start_hc(pdev);
 186
 187         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 188         if (retval == 0) {
 189                 device_wakeup_enable(hcd->self.controller);
 190                 return retval;
 191         }
 192
 193         /* Error handling */
 194         at91_stop_hc(pdev);
 195
 196  err:
 197         usb_put_hcd(hcd);
 198         return retval;
 199 }
 200
 201
 202 /* may be called with controller, bus, and devices active */
 203
 204 /**
 205  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
 206  * @dev: USB Host Controller being removed
 207  * Context: !in_interrupt()
 208  *
 209  * Reverses the effect of usb_hcd_at91_probe(), first invoking
 210  * the HCD's stop() method.  It is always called from a thread
 211  * context, "rmmod" or something similar.
 212  *
 213  */
 214 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
 215                                 struct platform_device *pdev)
 216 {
 217         usb_remove_hcd(hcd);
 218         at91_stop_hc(pdev);
 219         usb_put_hcd(hcd);
 220 }
 221
 222 /*-------------------------------------------------------------------------*/
 223 static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
 224 {
 225         if (!valid_port(port))
 226                 return;
 227
 228         if (!gpio_is_valid(pdata->vbus_pin[port]))
 229                 return;
 230
 231         gpio_set_value(pdata->vbus_pin[port],
 232                        pdata->vbus_pin_active_low[port] ^ enable);
 233 }
 234
 235 static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
 236 {
 237         if (!valid_port(port))
 238                 return -EINVAL;
 239
 240         if (!gpio_is_valid(pdata->vbus_pin[port]))
 241                 return -EINVAL;
 242
 243         return gpio_get_value(pdata->vbus_pin[port]) ^
 244                 pdata->vbus_pin_active_low[port];
 245 }
 246
 247 /*
 248  * Update the status data from the hub with the over-current indicator change.
 249  */
 250 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
 251 {
 252         struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
 253         int length = ohci_hub_status_data(hcd, buf);
 254         int port;
 255
 256         at91_for_each_port(port) {
 257                 if (pdata->overcurrent_changed[port]) {
 258                         if (!length)
 259                                 length = 1;
 260                         buf[0] |= 1 << (port + 1);
 261                 }
 262         }
 263
 264         return length;
 265 }
 266
 267 /*
 268  * Look at the control requests to the root hub and see if we need to override.
 269  */
 270 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 271                                  u16 wIndex, char *buf, u16 wLength)
 272 {
 273         struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
 274         struct usb_hub_descriptor *desc;
 275         int ret = -EINVAL;
 276         u32 *data = (u32 *)buf;
 277
 278         dev_dbg(hcd->self.controller,
 279                 "ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
 280                 hcd, typeReq, wValue, wIndex, buf, wLength);
 281
 282         wIndex--;
 283
 284         switch (typeReq) {
 285         case SetPortFeature:
 286                 if (wValue == USB_PORT_FEAT_POWER) {
 287                         dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
 288                         if (valid_port(wIndex)) {
 289                                 ohci_at91_usb_set_power(pdata, wIndex, 1);
 290                                 ret = 0;
 291                         }
 292
 293                         goto out;
 294                 }
 295                 break;
 296
 297         case ClearPortFeature:
 298                 switch (wValue) {
 299                 case USB_PORT_FEAT_C_OVER_CURRENT:
 300                         dev_dbg(hcd->self.controller,
 301                                 "ClearPortFeature: C_OVER_CURRENT\n");
 302
 303                         if (valid_port(wIndex)) {
 304                                 pdata->overcurrent_changed[wIndex] = 0;
 305                                 pdata->overcurrent_status[wIndex] = 0;
 306                         }
 307
 308                         goto out;
 309
 310                 case USB_PORT_FEAT_OVER_CURRENT:
 311                         dev_dbg(hcd->self.controller,
 312                                 "ClearPortFeature: OVER_CURRENT\n");
 313
 314                         if (valid_port(wIndex))
 315                                 pdata->overcurrent_status[wIndex] = 0;
 316
 317                         goto out;
 318
 319                 case USB_PORT_FEAT_POWER:
 320                         dev_dbg(hcd->self.controller,
 321                                 "ClearPortFeature: POWER\n");
 322
 323                         if (valid_port(wIndex)) {
 324                                 ohci_at91_usb_set_power(pdata, wIndex, 0);
 325                                 return 0;
 326                         }
 327                 }
 328                 break;
 329         }
 330
 331         ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
 332         if (ret)
 333                 goto out;
 334
 335         switch (typeReq) {
 336         case GetHubDescriptor:
 337
 338                 /* update the hub's descriptor */
 339
 340                 desc = (struct usb_hub_descriptor *)buf;
 341
 342                 dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
 343                         desc->wHubCharacteristics);
 344
 345                 /* remove the old configurations for power-switching, and
 346                  * over-current protection, and insert our new configuration
 347                  */
 348
 349                 desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
 350                 desc->wHubCharacteristics |= cpu_to_le16(0x0001);
 351
 352                 if (pdata->overcurrent_supported) {
 353                         desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
 354                         desc->wHubCharacteristics |=  cpu_to_le16(0x0008|0x0001);
 355                 }
 356
 357                 dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
 358                         desc->wHubCharacteristics);
 359
 360                 return ret;
 361
 362         case GetPortStatus:
 363                 /* check port status */
 364
 365                 dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
 366
 367                 if (valid_port(wIndex)) {
 368                         if (!ohci_at91_usb_get_power(pdata, wIndex))
 369                                 *data &= ~cpu_to_le32(RH_PS_PPS);
 370
 371                         if (pdata->overcurrent_changed[wIndex])
 372                                 *data |= cpu_to_le32(RH_PS_OCIC);
 373
 374                         if (pdata->overcurrent_status[wIndex])
 375                                 *data |= cpu_to_le32(RH_PS_POCI);
 376                 }
 377         }
 378
 379  out:
 380         return ret;
 381 }
 382
 383 /*-------------------------------------------------------------------------*/
 384
 385 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
 386 {
 387         struct platform_device *pdev = data;
 388         struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
 389         int val, gpio, port;
 390
 391         /* From the GPIO notifying the over-current situation, find
 392          * out the corresponding port */
 393         at91_for_each_port(port) {
 394                 if (gpio_is_valid(pdata->overcurrent_pin[port]) &&
 395                                 gpio_to_irq(pdata->overcurrent_pin[port]) == irq) {
 396                         gpio = pdata->overcurrent_pin[port];
 397                         break;
 398                 }
 399         }
 400
 401         if (port == AT91_MAX_USBH_PORTS) {
 402                 dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
 403                 return IRQ_HANDLED;
 404         }
 405
 406         val = gpio_get_value(gpio);
 407
 408         /* When notified of an over-current situation, disable power
 409            on the corresponding port, and mark this port in
 410            over-current. */
 411         if (!val) {
 412                 ohci_at91_usb_set_power(pdata, port, 0);
 413                 pdata->overcurrent_status[port]  = 1;
 414                 pdata->overcurrent_changed[port] = 1;
 415         }
 416
 417         dev_dbg(& pdev->dev, "overcurrent situation %s\n",
 418                 val ? "exited" : "notified");
 419
 420         return IRQ_HANDLED;
 421 }
 422
 423 #ifdef CONFIG_OF
 424 static const struct of_device_id at91_ohci_dt_ids[] = {
 425         { .compatible = "atmel,at91rm9200-ohci" },
 426         { /* sentinel */ }
 427 };
 428
 429 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
 430
 431 static int ohci_at91_of_init(struct platform_device *pdev)
 432 {
 433         struct device_node *np = pdev->dev.of_node;
 434         int i, gpio, ret;
 435         enum of_gpio_flags flags;
 436         struct at91_usbh_data   *pdata;
 437         u32 ports;
 438
 439         if (!np)
 440                 return 0;
 441
 442         /* Right now device-tree probed devices don't get dma_mask set.
 443          * Since shared usb code relies on it, set it here for now.
 444          * Once we have dma capability bindings this can go away.
 445          */
 446         ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 447         if (ret)
 448                 return ret;
 449
 450         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 451         if (!pdata)
 452                 return -ENOMEM;
 453
 454         if (!of_property_read_u32(np, "num-ports", &ports))
 455                 pdata->ports = ports;
 456
 457         at91_for_each_port(i) {
 458                 gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i, &flags);
 459                 pdata->vbus_pin[i] = gpio;
 460                 if (!gpio_is_valid(gpio))
 461                         continue;
 462                 pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
 463         }
 464
 465         at91_for_each_port(i)
 466                 pdata->overcurrent_pin[i] =
 467                         of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);
 468
 469         pdev->dev.platform_data = pdata;
 470
 471         return 0;
 472 }
 473 #else
 474 static int ohci_at91_of_init(struct platform_device *pdev)
 475 {
 476         return 0;
 477 }
 478 #endif
 479
 480 /*-------------------------------------------------------------------------*/
 481
 482 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
 483 {
 484         struct at91_usbh_data   *pdata;
 485         int                     i;
 486         int                     gpio;
 487         int                     ret;
 488
 489         ret = ohci_at91_of_init(pdev);
 490         if (ret)
 491                 return ret;
 492
 493         pdata = dev_get_platdata(&pdev->dev);
 494
 495         if (pdata) {
 496                 at91_for_each_port(i) {
 497                         /*
 498                          * do not configure PIO if not in relation with
 499                          * real USB port on board
 500                          */
 501                         if (i >= pdata->ports) {
 502                                 pdata->vbus_pin[i] = -EINVAL;
 503                                 pdata->overcurrent_pin[i] = -EINVAL;
 504                                 break;
 505                         }
 506
 507                         if (!gpio_is_valid(pdata->vbus_pin[i]))
 508                                 continue;
 509                         gpio = pdata->vbus_pin[i];
 510
 511                         ret = gpio_request(gpio, "ohci_vbus");
 512                         if (ret) {
 513                                 dev_err(&pdev->dev,
 514                                         "can't request vbus gpio %d\n", gpio);
 515                                 continue;
 516                         }
 517                         ret = gpio_direction_output(gpio,
 518                                                 !pdata->vbus_pin_active_low[i]);
 519                         if (ret) {
 520                                 dev_err(&pdev->dev,
 521                                         "can't put vbus gpio %d as output %d\n",
 522                                         gpio, !pdata->vbus_pin_active_low[i]);
 523                                 gpio_free(gpio);
 524                                 continue;
 525                         }
 526
 527                         ohci_at91_usb_set_power(pdata, i, 1);
 528                 }
 529
 530                 at91_for_each_port(i) {
 531                         if (!gpio_is_valid(pdata->overcurrent_pin[i]))
 532                                 continue;
 533                         gpio = pdata->overcurrent_pin[i];
 534
 535                         ret = gpio_request(gpio, "ohci_overcurrent");
 536                         if (ret) {
 537                                 dev_err(&pdev->dev,
 538                                         "can't request overcurrent gpio %d\n",
 539                                         gpio);
 540                                 continue;
 541                         }
 542
 543                         ret = gpio_direction_input(gpio);
 544                         if (ret) {
 545                                 dev_err(&pdev->dev,
 546                                         "can't configure overcurrent gpio %d as input\n",
 547                                         gpio);
 548                                 gpio_free(gpio);
 549                                 continue;
 550                         }
 551
 552                         ret = request_irq(gpio_to_irq(gpio),
 553                                           ohci_hcd_at91_overcurrent_irq,
 554                                           IRQF_SHARED, "ohci_overcurrent", pdev);
 555                         if (ret) {
 556                                 gpio_free(gpio);
 557                                 dev_err(&pdev->dev,
 558                                         "can't get gpio IRQ for overcurrent\n");
 559                         }
 560                 }
 561         }
 562
 563         device_init_wakeup(&pdev->dev, 1);
 564         return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
 565 }
 566
 567 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
 568 {
 569         struct at91_usbh_data   *pdata = dev_get_platdata(&pdev->dev);
 570         int                     i;
 571
 572         if (pdata) {
 573                 at91_for_each_port(i) {
 574                         if (!gpio_is_valid(pdata->vbus_pin[i]))
 575                                 continue;
 576                         ohci_at91_usb_set_power(pdata, i, 0);
 577                         gpio_free(pdata->vbus_pin[i]);
 578                 }
 579
 580                 at91_for_each_port(i) {
 581                         if (!gpio_is_valid(pdata->overcurrent_pin[i]))
 582                                 continue;
 583                         free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
 584                         gpio_free(pdata->overcurrent_pin[i]);
 585                 }
 586         }
 587
 588         device_init_wakeup(&pdev->dev, 0);
 589         usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
 590         return 0;
 591 }
 592
 593 #ifdef CONFIG_PM
 594
 595 static int
 596 ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
 597 {
 598         struct usb_hcd  *hcd = platform_get_drvdata(pdev);
 599         struct ohci_hcd *ohci = hcd_to_ohci(hcd);
 600         bool            do_wakeup = device_may_wakeup(&pdev->dev);
 601         int             ret;
 602
 603         if (do_wakeup)
 604                 enable_irq_wake(hcd->irq);
 605
 606         ret = ohci_suspend(hcd, do_wakeup);
 607         if (ret) {
 608                 disable_irq_wake(hcd->irq);
 609                 return ret;
 610         }
 611         /*
 612          * The integrated transceivers seem unable to notice disconnect,
 613          * reconnect, or wakeup without the 48 MHz clock active.  so for
 614          * correctness, always discard connection state (using reset).
 615          *
 616          * REVISIT: some boards will be able to turn VBUS off...
 617          */
 618         if (at91_suspend_entering_slow_clock()) {
 619                 ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
 620                 ohci->hc_control &= OHCI_CTRL_RWC;
 621                 ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
 622                 ohci->rh_state = OHCI_RH_HALTED;
 623
 624                 /* flush the writes */
 625                 (void) ohci_readl (ohci, &ohci->regs->control);
 626                 at91_stop_clock();
 627         }
 628
 629         return ret;
 630 }
 631
 632 static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
 633 {
 634         struct usb_hcd  *hcd = platform_get_drvdata(pdev);
 635
 636         if (device_may_wakeup(&pdev->dev))
 637                 disable_irq_wake(hcd->irq);
 638
 639         if (!clocked)
 640                 at91_start_clock();
 641
 642         ohci_resume(hcd, false);
 643         return 0;
 644 }
 645 #else
 646 #define ohci_hcd_at91_drv_suspend NULL
 647 #define ohci_hcd_at91_drv_resume  NULL
 648 #endif
 649
 650 static struct platform_driver ohci_hcd_at91_driver = {
 651         .probe          = ohci_hcd_at91_drv_probe,
 652         .remove         = ohci_hcd_at91_drv_remove,
 653         .shutdown       = usb_hcd_platform_shutdown,
 654         .suspend        = ohci_hcd_at91_drv_suspend,
 655         .resume         = ohci_hcd_at91_drv_resume,
 656         .driver         = {
 657                 .name   = "at91_ohci",
 658                 .of_match_table = of_match_ptr(at91_ohci_dt_ids),
 659         },
 660 };
 661
 662 static int __init ohci_at91_init(void)
 663 {
 664         if (usb_disabled())
 665                 return -ENODEV;
 666
 667         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 668         ohci_init_driver(&ohci_at91_hc_driver, NULL);
 669
 670         /*
 671          * The Atmel HW has some unusual quirks, which require Atmel-specific
 672          * workarounds. We override certain hc_driver functions here to
 673          * achieve that. We explicitly do not enhance ohci_driver_overrides to
 674          * allow this more easily, since this is an unusual case, and we don't
 675          * want to encourage others to override these functions by making it
 676          * too easy.
 677          */
 678
 679         ohci_at91_hc_driver.hub_status_data     = ohci_at91_hub_status_data;
 680         ohci_at91_hc_driver.hub_control         = ohci_at91_hub_control;
 681
 682         return platform_driver_register(&ohci_hcd_at91_driver);
 683 }
 684 module_init(ohci_at91_init);
 685
 686 static void __exit ohci_at91_cleanup(void)
 687 {
 688         platform_driver_unregister(&ohci_hcd_at91_driver);
 689 }
 690 module_exit(ohci_at91_cleanup);
 691
 692 MODULE_DESCRIPTION(DRIVER_DESC);
 693 MODULE_LICENSE("GPL");
 694 MODULE_ALIAS("platform:at91_ohci");