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/mfd/syscon.h>
  25 #include <linux/regmap.h>
  26 #include <linux/usb.h>
  27 #include <linux/usb/hcd.h>
  28 #include <soc/at91/atmel-sfr.h>
  29
  30 #include "ohci.h"
  31
  32 #define valid_port(index)       ((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
  33 #define at91_for_each_port(index)       \
  34                 for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
  35
  36 /* interface, function and usb clocks; sometimes also an AHB clock */
  37 #define hcd_to_ohci_at91_priv(h) \
  38         ((struct ohci_at91_priv *)hcd_to_ohci(h)->priv)
  39
  40 #define AT91_MAX_USBH_PORTS     3
  41 struct at91_usbh_data {
  42         int vbus_pin[AT91_MAX_USBH_PORTS];      /* port power-control pin */
  43         int overcurrent_pin[AT91_MAX_USBH_PORTS];
  44         u8 ports;                               /* number of ports on root hub */
  45         u8 overcurrent_supported;
  46         u8 vbus_pin_active_low[AT91_MAX_USBH_PORTS];
  47         u8 overcurrent_status[AT91_MAX_USBH_PORTS];
  48         u8 overcurrent_changed[AT91_MAX_USBH_PORTS];
  49 };
  50
  51 struct ohci_at91_priv {
  52         struct clk *iclk;
  53         struct clk *fclk;
  54         struct clk *hclk;
  55         bool clocked;
  56         bool wakeup;            /* Saved wake-up state for resume */
  57         struct regmap *sfr_regmap;
  58 };
  59 /* interface and function clocks; sometimes also an AHB clock */
  60
  61 #define DRIVER_DESC "OHCI Atmel driver"
  62
  63 static const char hcd_name[] = "ohci-atmel";
  64
  65 static struct hc_driver __read_mostly ohci_at91_hc_driver;
  66
  67 static const struct ohci_driver_overrides ohci_at91_drv_overrides __initconst = {
  68         .extra_priv_size = sizeof(struct ohci_at91_priv),
  69 };
  70
  71 extern int usb_disabled(void);
  72
  73 /*-------------------------------------------------------------------------*/
  74
  75 static void at91_start_clock(struct ohci_at91_priv *ohci_at91)
  76 {
  77         if (ohci_at91->clocked)
  78                 return;
  79
  80         clk_set_rate(ohci_at91->fclk, 48000000);
  81         clk_prepare_enable(ohci_at91->hclk);
  82         clk_prepare_enable(ohci_at91->iclk);
  83         clk_prepare_enable(ohci_at91->fclk);
  84         ohci_at91->clocked = true;
  85 }
  86
  87 static void at91_stop_clock(struct ohci_at91_priv *ohci_at91)
  88 {
  89         if (!ohci_at91->clocked)
  90                 return;
  91
  92         clk_disable_unprepare(ohci_at91->fclk);
  93         clk_disable_unprepare(ohci_at91->iclk);
  94         clk_disable_unprepare(ohci_at91->hclk);
  95         ohci_at91->clocked = false;
  96 }
  97
  98 static void at91_start_hc(struct platform_device *pdev)
  99 {
 100         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 101         struct ohci_regs __iomem *regs = hcd->regs;
 102         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 103
 104         dev_dbg(&pdev->dev, "start\n");
 105
 106         /*
 107          * Start the USB clocks.
 108          */
 109         at91_start_clock(ohci_at91);
 110
 111         /*
 112          * The USB host controller must remain in reset.
 113          */
 114         writel(0, &regs->control);
 115 }
 116
 117 static void at91_stop_hc(struct platform_device *pdev)
 118 {
 119         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 120         struct ohci_regs __iomem *regs = hcd->regs;
 121         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 122
 123         dev_dbg(&pdev->dev, "stop\n");
 124
 125         /*
 126          * Put the USB host controller into reset.
 127          */
 128         writel(0, &regs->control);
 129
 130         /*
 131          * Stop the USB clocks.
 132          */
 133         at91_stop_clock(ohci_at91);
 134 }
 135
 136
 137 /*-------------------------------------------------------------------------*/
 138
 139 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
 140
 141 static struct regmap *at91_dt_syscon_sfr(void)
 142 {
 143         struct regmap *regmap;
 144
 145         regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");
 146         if (IS_ERR(regmap))
 147                 regmap = NULL;
 148
 149         return regmap;
 150 }
 151
 152 /* configure so an HC device and id are always provided */
 153 /* always called with process context; sleeping is OK */
 154
 155
 156 /**
 157  * usb_hcd_at91_probe - initialize AT91-based HCDs
 158  * Context: !in_interrupt()
 159  *
 160  * Allocates basic resources for this USB host controller, and
 161  * then invokes the start() method for the HCD associated with it
 162  * through the hotplug entry's driver_data.
 163  */
 164 static int usb_hcd_at91_probe(const struct hc_driver *driver,
 165                         struct platform_device *pdev)
 166 {
 167         struct at91_usbh_data *board;
 168         struct ohci_hcd *ohci;
 169         int retval;
 170         struct usb_hcd *hcd;
 171         struct ohci_at91_priv *ohci_at91;
 172         struct device *dev = &pdev->dev;
 173         struct resource *res;
 174         int irq;
 175
 176         irq = platform_get_irq(pdev, 0);
 177         if (irq < 0) {
 178                 dev_dbg(dev, "hcd probe: missing irq resource\n");
 179                 return irq;
 180         }
 181
 182         hcd = usb_create_hcd(driver, dev, "at91");
 183         if (!hcd)
 184                 return -ENOMEM;
 185         ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 186
 187         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 188         hcd->regs = devm_ioremap_resource(dev, res);
 189         if (IS_ERR(hcd->regs)) {
 190                 retval = PTR_ERR(hcd->regs);
 191                 goto err;
 192         }
 193         hcd->rsrc_start = res->start;
 194         hcd->rsrc_len = resource_size(res);
 195
 196         ohci_at91->iclk = devm_clk_get(dev, "ohci_clk");
 197         if (IS_ERR(ohci_at91->iclk)) {
 198                 dev_err(dev, "failed to get ohci_clk\n");
 199                 retval = PTR_ERR(ohci_at91->iclk);
 200                 goto err;
 201         }
 202         ohci_at91->fclk = devm_clk_get(dev, "uhpck");
 203         if (IS_ERR(ohci_at91->fclk)) {
 204                 dev_err(dev, "failed to get uhpck\n");
 205                 retval = PTR_ERR(ohci_at91->fclk);
 206                 goto err;
 207         }
 208         ohci_at91->hclk = devm_clk_get(dev, "hclk");
 209         if (IS_ERR(ohci_at91->hclk)) {
 210                 dev_err(dev, "failed to get hclk\n");
 211                 retval = PTR_ERR(ohci_at91->hclk);
 212                 goto err;
 213         }
 214
 215         ohci_at91->sfr_regmap = at91_dt_syscon_sfr();
 216         if (!ohci_at91->sfr_regmap)
 217                 dev_warn(dev, "failed to find sfr node\n");
 218
 219         board = hcd->self.controller->platform_data;
 220         ohci = hcd_to_ohci(hcd);
 221         ohci->num_ports = board->ports;
 222         at91_start_hc(pdev);
 223
 224         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 225         if (retval == 0) {
 226                 device_wakeup_enable(hcd->self.controller);
 227                 return retval;
 228         }
 229
 230         /* Error handling */
 231         at91_stop_hc(pdev);
 232
 233  err:
 234         usb_put_hcd(hcd);
 235         return retval;
 236 }
 237
 238
 239 /* may be called with controller, bus, and devices active */
 240
 241 /**
 242  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
 243  * @dev: USB Host Controller being removed
 244  * Context: !in_interrupt()
 245  *
 246  * Reverses the effect of usb_hcd_at91_probe(), first invoking
 247  * the HCD's stop() method.  It is always called from a thread
 248  * context, "rmmod" or something similar.
 249  *
 250  */
 251 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
 252                                 struct platform_device *pdev)
 253 {
 254         usb_remove_hcd(hcd);
 255         at91_stop_hc(pdev);
 256         usb_put_hcd(hcd);
 257 }
 258
 259 /*-------------------------------------------------------------------------*/
 260 static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
 261 {
 262         if (!valid_port(port))
 263                 return;
 264
 265         if (!gpio_is_valid(pdata->vbus_pin[port]))
 266                 return;
 267
 268         gpio_set_value(pdata->vbus_pin[port],
 269                        pdata->vbus_pin_active_low[port] ^ enable);
 270 }
 271
 272 static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
 273 {
 274         if (!valid_port(port))
 275                 return -EINVAL;
 276
 277         if (!gpio_is_valid(pdata->vbus_pin[port]))
 278                 return -EINVAL;
 279
 280         return gpio_get_value(pdata->vbus_pin[port]) ^
 281                 pdata->vbus_pin_active_low[port];
 282 }
 283
 284 /*
 285  * Update the status data from the hub with the over-current indicator change.
 286  */
 287 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
 288 {
 289         struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
 290         int length = ohci_hub_status_data(hcd, buf);
 291         int port;
 292
 293         at91_for_each_port(port) {
 294                 if (pdata->overcurrent_changed[port]) {
 295                         if (!length)
 296                                 length = 1;
 297                         buf[0] |= 1 << (port + 1);
 298                 }
 299         }
 300
 301         return length;
 302 }
 303
 304 static int ohci_at91_port_suspend(struct regmap *regmap, u8 set)
 305 {
 306         u32 regval;
 307         int ret;
 308
 309         if (!regmap)
 310                 return 0;
 311
 312         ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);
 313         if (ret)
 314                 return ret;
 315
 316         if (set)
 317                 regval |= AT91_OHCIICR_USB_SUSPEND;
 318         else
 319                 regval &= ~AT91_OHCIICR_USB_SUSPEND;
 320
 321         regmap_write(regmap, AT91_SFR_OHCIICR, regval);
 322
 323         return 0;
 324 }
 325
 326 /*
 327  * Look at the control requests to the root hub and see if we need to override.
 328  */
 329 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 330                                  u16 wIndex, char *buf, u16 wLength)
 331 {
 332         struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
 333         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 334         struct usb_hub_descriptor *desc;
 335         int ret = -EINVAL;
 336         u32 *data = (u32 *)buf;
 337
 338         dev_dbg(hcd->self.controller,
 339                 "ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
 340                 hcd, typeReq, wValue, wIndex, buf, wLength);
 341
 342         wIndex--;
 343
 344         switch (typeReq) {
 345         case SetPortFeature:
 346                 switch (wValue) {
 347                 case USB_PORT_FEAT_POWER:
 348                         dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
 349                         if (valid_port(wIndex)) {
 350                                 ohci_at91_usb_set_power(pdata, wIndex, 1);
 351                                 ret = 0;
 352                         }
 353
 354                         goto out;
 355
 356                 case USB_PORT_FEAT_SUSPEND:
 357                         dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n");
 358                         if (valid_port(wIndex)) {
 359                                 ohci_at91_port_suspend(ohci_at91->sfr_regmap,
 360                                                        1);
 361                                 return 0;
 362                         }
 363                         break;
 364                 }
 365                 break;
 366
 367         case ClearPortFeature:
 368                 switch (wValue) {
 369                 case USB_PORT_FEAT_C_OVER_CURRENT:
 370                         dev_dbg(hcd->self.controller,
 371                                 "ClearPortFeature: C_OVER_CURRENT\n");
 372
 373                         if (valid_port(wIndex)) {
 374                                 pdata->overcurrent_changed[wIndex] = 0;
 375                                 pdata->overcurrent_status[wIndex] = 0;
 376                         }
 377
 378                         goto out;
 379
 380                 case USB_PORT_FEAT_OVER_CURRENT:
 381                         dev_dbg(hcd->self.controller,
 382                                 "ClearPortFeature: OVER_CURRENT\n");
 383
 384                         if (valid_port(wIndex))
 385                                 pdata->overcurrent_status[wIndex] = 0;
 386
 387                         goto out;
 388
 389                 case USB_PORT_FEAT_POWER:
 390                         dev_dbg(hcd->self.controller,
 391                                 "ClearPortFeature: POWER\n");
 392
 393                         if (valid_port(wIndex)) {
 394                                 ohci_at91_usb_set_power(pdata, wIndex, 0);
 395                                 return 0;
 396                         }
 397                         break;
 398
 399                 case USB_PORT_FEAT_SUSPEND:
 400                         dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n");
 401                         if (valid_port(wIndex)) {
 402                                 ohci_at91_port_suspend(ohci_at91->sfr_regmap,
 403                                                        0);
 404                                 return 0;
 405                         }
 406                         break;
 407                 }
 408                 break;
 409         }
 410
 411         ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
 412         if (ret)
 413                 goto out;
 414
 415         switch (typeReq) {
 416         case GetHubDescriptor:
 417
 418                 /* update the hub's descriptor */
 419
 420                 desc = (struct usb_hub_descriptor *)buf;
 421
 422                 dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
 423                         desc->wHubCharacteristics);
 424
 425                 /* remove the old configurations for power-switching, and
 426                  * over-current protection, and insert our new configuration
 427                  */
 428
 429                 desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
 430                 desc->wHubCharacteristics |=
 431                         cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM);
 432
 433                 if (pdata->overcurrent_supported) {
 434                         desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
 435                         desc->wHubCharacteristics |=
 436                                 cpu_to_le16(HUB_CHAR_INDV_PORT_OCPM);
 437                 }
 438
 439                 dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
 440                         desc->wHubCharacteristics);
 441
 442                 return ret;
 443
 444         case GetPortStatus:
 445                 /* check port status */
 446
 447                 dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
 448
 449                 if (valid_port(wIndex)) {
 450                         if (!ohci_at91_usb_get_power(pdata, wIndex))
 451                                 *data &= ~cpu_to_le32(RH_PS_PPS);
 452
 453                         if (pdata->overcurrent_changed[wIndex])
 454                                 *data |= cpu_to_le32(RH_PS_OCIC);
 455
 456                         if (pdata->overcurrent_status[wIndex])
 457                                 *data |= cpu_to_le32(RH_PS_POCI);
 458                 }
 459         }
 460
 461  out:
 462         return ret;
 463 }
 464
 465 /*-------------------------------------------------------------------------*/
 466
 467 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
 468 {
 469         struct platform_device *pdev = data;
 470         struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
 471         int val, gpio, port;
 472
 473         /* From the GPIO notifying the over-current situation, find
 474          * out the corresponding port */
 475         at91_for_each_port(port) {
 476                 if (gpio_is_valid(pdata->overcurrent_pin[port]) &&
 477                                 gpio_to_irq(pdata->overcurrent_pin[port]) == irq) {
 478                         gpio = pdata->overcurrent_pin[port];
 479                         break;
 480                 }
 481         }
 482
 483         if (port == AT91_MAX_USBH_PORTS) {
 484                 dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
 485                 return IRQ_HANDLED;
 486         }
 487
 488         val = gpio_get_value(gpio);
 489
 490         /* When notified of an over-current situation, disable power
 491            on the corresponding port, and mark this port in
 492            over-current. */
 493         if (!val) {
 494                 ohci_at91_usb_set_power(pdata, port, 0);
 495                 pdata->overcurrent_status[port]  = 1;
 496                 pdata->overcurrent_changed[port] = 1;
 497         }
 498
 499         dev_dbg(& pdev->dev, "overcurrent situation %s\n",
 500                 val ? "exited" : "notified");
 501
 502         return IRQ_HANDLED;
 503 }
 504
 505 static const struct of_device_id at91_ohci_dt_ids[] = {
 506         { .compatible = "atmel,at91rm9200-ohci" },
 507         { /* sentinel */ }
 508 };
 509
 510 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
 511
 512 /*-------------------------------------------------------------------------*/
 513
 514 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
 515 {
 516         struct device_node *np = pdev->dev.of_node;
 517         struct at91_usbh_data   *pdata;
 518         int                     i;
 519         int                     gpio;
 520         int                     ret;
 521         enum of_gpio_flags      flags;
 522         u32                     ports;
 523
 524         /* Right now device-tree probed devices don't get dma_mask set.
 525          * Since shared usb code relies on it, set it here for now.
 526          * Once we have dma capability bindings this can go away.
 527          */
 528         ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 529         if (ret)
 530                 return ret;
 531
 532         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 533         if (!pdata)
 534                 return -ENOMEM;
 535
 536         pdev->dev.platform_data = pdata;
 537
 538         if (!of_property_read_u32(np, "num-ports", &ports))
 539                 pdata->ports = ports;
 540
 541         at91_for_each_port(i) {
 542                 /*
 543                  * do not configure PIO if not in relation with
 544                  * real USB port on board
 545                  */
 546                 if (i >= pdata->ports) {
 547                         pdata->vbus_pin[i] = -EINVAL;
 548                         pdata->overcurrent_pin[i] = -EINVAL;
 549                         continue;
 550                 }
 551
 552                 gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i,
 553                                                &flags);
 554                 pdata->vbus_pin[i] = gpio;
 555                 if (!gpio_is_valid(gpio))
 556                         continue;
 557                 pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
 558
 559                 ret = gpio_request(gpio, "ohci_vbus");
 560                 if (ret) {
 561                         dev_err(&pdev->dev,
 562                                 "can't request vbus gpio %d\n", gpio);
 563                         continue;
 564                 }
 565                 ret = gpio_direction_output(gpio,
 566                                         !pdata->vbus_pin_active_low[i]);
 567                 if (ret) {
 568                         dev_err(&pdev->dev,
 569                                 "can't put vbus gpio %d as output %d\n",
 570                                 gpio, !pdata->vbus_pin_active_low[i]);
 571                         gpio_free(gpio);
 572                         continue;
 573                 }
 574
 575                 ohci_at91_usb_set_power(pdata, i, 1);
 576         }
 577
 578         at91_for_each_port(i) {
 579                 if (i >= pdata->ports)
 580                         break;
 581
 582                 pdata->overcurrent_pin[i] =
 583                         of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);
 584
 585                 if (!gpio_is_valid(pdata->overcurrent_pin[i]))
 586                         continue;
 587                 gpio = pdata->overcurrent_pin[i];
 588
 589                 ret = gpio_request(gpio, "ohci_overcurrent");
 590                 if (ret) {
 591                         dev_err(&pdev->dev,
 592                                 "can't request overcurrent gpio %d\n",
 593                                 gpio);
 594                         continue;
 595                 }
 596
 597                 ret = gpio_direction_input(gpio);
 598                 if (ret) {
 599                         dev_err(&pdev->dev,
 600                                 "can't configure overcurrent gpio %d as input\n",
 601                                 gpio);
 602                         gpio_free(gpio);
 603                         continue;
 604                 }
 605
 606                 ret = request_irq(gpio_to_irq(gpio),
 607                                   ohci_hcd_at91_overcurrent_irq,
 608                                   IRQF_SHARED, "ohci_overcurrent", pdev);
 609                 if (ret) {
 610                         gpio_free(gpio);
 611                         dev_err(&pdev->dev,
 612                                 "can't get gpio IRQ for overcurrent\n");
 613                 }
 614         }
 615
 616         device_init_wakeup(&pdev->dev, 1);
 617         return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
 618 }
 619
 620 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
 621 {
 622         struct at91_usbh_data   *pdata = dev_get_platdata(&pdev->dev);
 623         int                     i;
 624
 625         if (pdata) {
 626                 at91_for_each_port(i) {
 627                         if (!gpio_is_valid(pdata->vbus_pin[i]))
 628                                 continue;
 629                         ohci_at91_usb_set_power(pdata, i, 0);
 630                         gpio_free(pdata->vbus_pin[i]);
 631                 }
 632
 633                 at91_for_each_port(i) {
 634                         if (!gpio_is_valid(pdata->overcurrent_pin[i]))
 635                                 continue;
 636                         free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
 637                         gpio_free(pdata->overcurrent_pin[i]);
 638                 }
 639         }
 640
 641         device_init_wakeup(&pdev->dev, 0);
 642         usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
 643         return 0;
 644 }
 645
 646 static int __maybe_unused
 647 ohci_hcd_at91_drv_suspend(struct device *dev)
 648 {
 649         struct usb_hcd  *hcd = dev_get_drvdata(dev);
 650         struct ohci_hcd *ohci = hcd_to_ohci(hcd);
 651         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 652         int             ret;
 653
 654         /*
 655          * Disable wakeup if we are going to sleep with slow clock mode
 656          * enabled.
 657          */
 658         ohci_at91->wakeup = device_may_wakeup(dev)
 659                         && !at91_suspend_entering_slow_clock();
 660
 661         if (ohci_at91->wakeup)
 662                 enable_irq_wake(hcd->irq);
 663
 664         ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1);
 665
 666         ret = ohci_suspend(hcd, ohci_at91->wakeup);
 667         if (ret) {
 668                 if (ohci_at91->wakeup)
 669                         disable_irq_wake(hcd->irq);
 670                 return ret;
 671         }
 672         /*
 673          * The integrated transceivers seem unable to notice disconnect,
 674          * reconnect, or wakeup without the 48 MHz clock active.  so for
 675          * correctness, always discard connection state (using reset).
 676          *
 677          * REVISIT: some boards will be able to turn VBUS off...
 678          */
 679         if (!ohci_at91->wakeup) {
 680                 ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
 681                 ohci->hc_control &= OHCI_CTRL_RWC;
 682                 ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
 683                 ohci->rh_state = OHCI_RH_HALTED;
 684
 685                 /* flush the writes */
 686                 (void) ohci_readl (ohci, &ohci->regs->control);
 687                 at91_stop_clock(ohci_at91);
 688         }
 689
 690         return ret;
 691 }
 692
 693 static int __maybe_unused
 694 ohci_hcd_at91_drv_resume(struct device *dev)
 695 {
 696         struct usb_hcd  *hcd = dev_get_drvdata(dev);
 697         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 698
 699         if (ohci_at91->wakeup)
 700                 disable_irq_wake(hcd->irq);
 701
 702         at91_start_clock(ohci_at91);
 703
 704         ohci_resume(hcd, false);
 705
 706         ohci_at91_port_suspend(ohci_at91->sfr_regmap, 0);
 707
 708         return 0;
 709 }
 710
 711 static SIMPLE_DEV_PM_OPS(ohci_hcd_at91_pm_ops, ohci_hcd_at91_drv_suspend,
 712                                         ohci_hcd_at91_drv_resume);
 713
 714 static struct platform_driver ohci_hcd_at91_driver = {
 715         .probe          = ohci_hcd_at91_drv_probe,
 716         .remove         = ohci_hcd_at91_drv_remove,
 717         .shutdown       = usb_hcd_platform_shutdown,
 718         .driver         = {
 719                 .name   = "at91_ohci",
 720                 .pm     = &ohci_hcd_at91_pm_ops,
 721                 .of_match_table = at91_ohci_dt_ids,
 722         },
 723 };
 724
 725 static int __init ohci_at91_init(void)
 726 {
 727         if (usb_disabled())
 728                 return -ENODEV;
 729
 730         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 731         ohci_init_driver(&ohci_at91_hc_driver, &ohci_at91_drv_overrides);
 732
 733         /*
 734          * The Atmel HW has some unusual quirks, which require Atmel-specific
 735          * workarounds. We override certain hc_driver functions here to
 736          * achieve that. We explicitly do not enhance ohci_driver_overrides to
 737          * allow this more easily, since this is an unusual case, and we don't
 738          * want to encourage others to override these functions by making it
 739          * too easy.
 740          */
 741
 742         ohci_at91_hc_driver.hub_status_data     = ohci_at91_hub_status_data;
 743         ohci_at91_hc_driver.hub_control         = ohci_at91_hub_control;
 744
 745         return platform_driver_register(&ohci_hcd_at91_driver);
 746 }
 747 module_init(ohci_at91_init);
 748
 749 static void __exit ohci_at91_cleanup(void)
 750 {
 751         platform_driver_unregister(&ohci_hcd_at91_driver);
 752 }
 753 module_exit(ohci_at91_cleanup);
 754
 755 MODULE_DESCRIPTION(DRIVER_DESC);
 756 MODULE_LICENSE("GPL");
 757 MODULE_ALIAS("platform:at91_ohci");