drivers/usb/host/ohci-at91.c

   1 // SPDX-License-Identifier: GPL-1.0+
   2 /*
   3  * OHCI HCD (Host Controller Driver) for USB.
   4  *
   5  *  Copyright (C) 2004 SAN People (Pty) Ltd.
   6  *  Copyright (C) 2005 Thibaut VARENE <varenet@parisc-linux.org>
   7  *
   8  * AT91 Bus Glue
   9  *
  10  * Based on fragments of 2.4 driver by Rick Bronson.
  11  * Based on ohci-omap.c
  12  *
  13  * This file is licenced under the GPL.
  14  */
  15
  16 #include <linux/arm-smccc.h>
  17 #include <linux/clk.h>
  18 #include <linux/dma-mapping.h>
  19 #include <linux/gpio/consumer.h>
  20 #include <linux/of_platform.h>
  21 #include <linux/platform_device.h>
  22 #include <linux/platform_data/atmel.h>
  23 #include <linux/io.h>
  24 #include <linux/kernel.h>
  25 #include <linux/module.h>
  26 #include <linux/mfd/syscon.h>
  27 #include <linux/regmap.h>
  28 #include <linux/usb.h>
  29 #include <linux/usb/hcd.h>
  30 #include <soc/at91/atmel-sfr.h>
  31
  32 #include "ohci.h"
  33
  34 #define valid_port(index)       ((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
  35 #define at91_for_each_port(index)       \
  36                 for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
  37
  38 /* interface, function and usb clocks; sometimes also an AHB clock */
  39 #define hcd_to_ohci_at91_priv(h) \
  40         ((struct ohci_at91_priv *)hcd_to_ohci(h)->priv)
  41
  42 #define AT91_MAX_USBH_PORTS     3
  43 struct at91_usbh_data {
  44         struct gpio_desc *vbus_pin[AT91_MAX_USBH_PORTS];
  45         struct gpio_desc *overcurrent_pin[AT91_MAX_USBH_PORTS];
  46         u8 ports;                               /* number of ports on root hub */
  47         u8 overcurrent_supported;
  48         u8 overcurrent_status[AT91_MAX_USBH_PORTS];
  49         u8 overcurrent_changed[AT91_MAX_USBH_PORTS];
  50 };
  51
  52 struct ohci_at91_priv {
  53         struct clk *iclk;
  54         struct clk *fclk;
  55         struct clk *hclk;
  56         bool clocked;
  57         bool wakeup;            /* Saved wake-up state for resume */
  58         struct regmap *sfr_regmap;
  59         u32 suspend_smc_id;
  60 };
  61 /* interface and function clocks; sometimes also an AHB clock */
  62
  63 #define DRIVER_DESC "OHCI Atmel driver"
  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 /*-------------------------------------------------------------------------*/
  72
  73 static void at91_start_clock(struct ohci_at91_priv *ohci_at91)
  74 {
  75         if (ohci_at91->clocked)
  76                 return;
  77
  78         clk_set_rate(ohci_at91->fclk, 48000000);
  79         clk_prepare_enable(ohci_at91->hclk);
  80         clk_prepare_enable(ohci_at91->iclk);
  81         clk_prepare_enable(ohci_at91->fclk);
  82         ohci_at91->clocked = true;
  83 }
  84
  85 static void at91_stop_clock(struct ohci_at91_priv *ohci_at91)
  86 {
  87         if (!ohci_at91->clocked)
  88                 return;
  89
  90         clk_disable_unprepare(ohci_at91->fclk);
  91         clk_disable_unprepare(ohci_at91->iclk);
  92         clk_disable_unprepare(ohci_at91->hclk);
  93         ohci_at91->clocked = false;
  94 }
  95
  96 static void at91_start_hc(struct platform_device *pdev)
  97 {
  98         struct usb_hcd *hcd = platform_get_drvdata(pdev);
  99         struct ohci_regs __iomem *regs = hcd->regs;
 100         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 101
 102         dev_dbg(&pdev->dev, "start\n");
 103
 104         /*
 105          * Start the USB clocks.
 106          */
 107         at91_start_clock(ohci_at91);
 108
 109         /*
 110          * The USB host controller must remain in reset.
 111          */
 112         writel(0, &regs->control);
 113 }
 114
 115 static void at91_stop_hc(struct platform_device *pdev)
 116 {
 117         struct usb_hcd *hcd = platform_get_drvdata(pdev);
 118         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 119
 120         dev_dbg(&pdev->dev, "stop\n");
 121
 122         /*
 123          * Put the USB host controller into reset.
 124          */
 125         usb_hcd_platform_shutdown(pdev);
 126
 127         /*
 128          * Stop the USB clocks.
 129          */
 130         at91_stop_clock(ohci_at91);
 131 }
 132
 133
 134 /*-------------------------------------------------------------------------*/
 135
 136 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
 137
 138 static u32 at91_dt_suspend_smc(struct device *dev)
 139 {
 140         u32 suspend_smc_id;
 141
 142         if (!dev->of_node)
 143                 return 0;
 144
 145         if (of_property_read_u32(dev->of_node, "microchip,suspend-smc-id", &suspend_smc_id))
 146                 return 0;
 147
 148         return suspend_smc_id;
 149 }
 150
 151 static struct regmap *at91_dt_syscon_sfr(void)
 152 {
 153         struct regmap *regmap;
 154
 155         regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");
 156         if (IS_ERR(regmap)) {
 157                 regmap = syscon_regmap_lookup_by_compatible("microchip,sam9x60-sfr");
 158                 if (IS_ERR(regmap))
 159                         regmap = NULL;
 160         }
 161
 162         return regmap;
 163 }
 164
 165 /* configure so an HC device and id are always provided */
 166 /* always called with process context; sleeping is OK */
 167
 168
 169 /*
 170  * usb_hcd_at91_probe - initialize AT91-based HCDs
 171  * @driver:     Pointer to hc driver instance
 172  * @pdev:       USB controller to probe
 173  *
 174  * Context: task context, might sleep
 175  *
 176  * Allocates basic resources for this USB host controller, and
 177  * then invokes the start() method for the HCD associated with it
 178  * through the hotplug entry's driver_data.
 179  */
 180 static int usb_hcd_at91_probe(const struct hc_driver *driver,
 181                         struct platform_device *pdev)
 182 {
 183         struct at91_usbh_data *board;
 184         struct ohci_hcd *ohci;
 185         int retval;
 186         struct usb_hcd *hcd;
 187         struct ohci_at91_priv *ohci_at91;
 188         struct device *dev = &pdev->dev;
 189         struct resource *res;
 190         int irq;
 191
 192         irq = platform_get_irq(pdev, 0);
 193         if (irq < 0) {
 194                 dev_dbg(dev, "hcd probe: missing irq resource\n");
 195                 return irq;
 196         }
 197
 198         hcd = usb_create_hcd(driver, dev, "at91");
 199         if (!hcd)
 200                 return -ENOMEM;
 201         ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 202
 203         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 204         hcd->regs = devm_ioremap_resource(dev, res);
 205         if (IS_ERR(hcd->regs)) {
 206                 retval = PTR_ERR(hcd->regs);
 207                 goto err;
 208         }
 209         hcd->rsrc_start = res->start;
 210         hcd->rsrc_len = resource_size(res);
 211
 212         ohci_at91->iclk = devm_clk_get(dev, "ohci_clk");
 213         if (IS_ERR(ohci_at91->iclk)) {
 214                 dev_err(dev, "failed to get ohci_clk\n");
 215                 retval = PTR_ERR(ohci_at91->iclk);
 216                 goto err;
 217         }
 218         ohci_at91->fclk = devm_clk_get(dev, "uhpck");
 219         if (IS_ERR(ohci_at91->fclk)) {
 220                 dev_err(dev, "failed to get uhpck\n");
 221                 retval = PTR_ERR(ohci_at91->fclk);
 222                 goto err;
 223         }
 224         ohci_at91->hclk = devm_clk_get(dev, "hclk");
 225         if (IS_ERR(ohci_at91->hclk)) {
 226                 dev_err(dev, "failed to get hclk\n");
 227                 retval = PTR_ERR(ohci_at91->hclk);
 228                 goto err;
 229         }
 230
 231         ohci_at91->suspend_smc_id = at91_dt_suspend_smc(dev);
 232         if (!ohci_at91->suspend_smc_id)  {
 233                 dev_dbg(dev, "failed to find sfr suspend smc id, using regmap\n");
 234                 ohci_at91->sfr_regmap = at91_dt_syscon_sfr();
 235                 if (!ohci_at91->sfr_regmap)
 236                         dev_dbg(dev, "failed to find sfr node\n");
 237         }
 238
 239         board = hcd->self.controller->platform_data;
 240         ohci = hcd_to_ohci(hcd);
 241         ohci->num_ports = board->ports;
 242         at91_start_hc(pdev);
 243
 244         /*
 245          * The RemoteWakeupConnected bit has to be set explicitly
 246          * before calling ohci_run. The reset value of this bit is 0.
 247          */
 248         ohci->hc_control = OHCI_CTRL_RWC;
 249
 250         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 251         if (retval == 0) {
 252                 device_wakeup_enable(hcd->self.controller);
 253                 return retval;
 254         }
 255
 256         /* Error handling */
 257         at91_stop_hc(pdev);
 258
 259  err:
 260         usb_put_hcd(hcd);
 261         return retval;
 262 }
 263
 264
 265 /* may be called with controller, bus, and devices active */
 266
 267 /*
 268  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
 269  * @hcd:        USB controller to remove
 270  * @pdev:       Platform device required for cleanup
 271  *
 272  * Context: task context, might sleep
 273  *
 274  * Reverses the effect of usb_hcd_at91_probe(), first invoking
 275  * the HCD's stop() method.  It is always called from a thread
 276  * context, "rmmod" or something similar.
 277  */
 278 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
 279                                 struct platform_device *pdev)
 280 {
 281         usb_remove_hcd(hcd);
 282         at91_stop_hc(pdev);
 283         usb_put_hcd(hcd);
 284 }
 285
 286 /*-------------------------------------------------------------------------*/
 287 static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
 288 {
 289         if (!valid_port(port))
 290                 return;
 291
 292         gpiod_set_value(pdata->vbus_pin[port], enable);
 293 }
 294
 295 static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
 296 {
 297         if (!valid_port(port))
 298                 return -EINVAL;
 299
 300         return gpiod_get_value(pdata->vbus_pin[port]);
 301 }
 302
 303 /*
 304  * Update the status data from the hub with the over-current indicator change.
 305  */
 306 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
 307 {
 308         struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
 309         int length = ohci_hub_status_data(hcd, buf);
 310         int port;
 311
 312         at91_for_each_port(port) {
 313                 if (pdata->overcurrent_changed[port]) {
 314                         if (!length)
 315                                 length = 1;
 316                         buf[0] |= 1 << (port + 1);
 317                 }
 318         }
 319
 320         return length;
 321 }
 322
 323 static int ohci_at91_port_suspend(struct ohci_at91_priv *ohci_at91, u8 set)
 324 {
 325         struct regmap *regmap = ohci_at91->sfr_regmap;
 326         u32 regval;
 327         int ret;
 328
 329         if (ohci_at91->suspend_smc_id) {
 330                 struct arm_smccc_res res;
 331
 332                 arm_smccc_smc(ohci_at91->suspend_smc_id, set, 0, 0, 0, 0, 0, 0, &res);
 333                 if (res.a0)
 334                         return -EINVAL;
 335         } else if (regmap) {
 336                 ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);
 337                 if (ret)
 338                         return ret;
 339
 340                 if (set)
 341                         regval |= AT91_OHCIICR_USB_SUSPEND;
 342                 else
 343                         regval &= ~AT91_OHCIICR_USB_SUSPEND;
 344
 345                 regmap_write(regmap, AT91_SFR_OHCIICR, regval);
 346         }
 347
 348         return 0;
 349 }
 350
 351 /*
 352  * Look at the control requests to the root hub and see if we need to override.
 353  */
 354 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 355                                  u16 wIndex, char *buf, u16 wLength)
 356 {
 357         struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
 358         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 359         struct usb_hub_descriptor *desc;
 360         int ret = -EINVAL;
 361         u32 *data = (u32 *)buf;
 362
 363         dev_dbg(hcd->self.controller,
 364                 "ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
 365                 hcd, typeReq, wValue, wIndex, buf, wLength);
 366
 367         wIndex--;
 368
 369         switch (typeReq) {
 370         case SetPortFeature:
 371                 switch (wValue) {
 372                 case USB_PORT_FEAT_POWER:
 373                         dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
 374                         if (valid_port(wIndex)) {
 375                                 ohci_at91_usb_set_power(pdata, wIndex, 1);
 376                                 ret = 0;
 377                         }
 378
 379                         goto out;
 380
 381                 case USB_PORT_FEAT_SUSPEND:
 382                         dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n");
 383                         if (valid_port(wIndex)) {
 384                                 ohci_at91_port_suspend(ohci_at91, 1);
 385                                 return 0;
 386                         }
 387                         break;
 388                 }
 389                 break;
 390
 391         case ClearPortFeature:
 392                 switch (wValue) {
 393                 case USB_PORT_FEAT_C_OVER_CURRENT:
 394                         dev_dbg(hcd->self.controller,
 395                                 "ClearPortFeature: C_OVER_CURRENT\n");
 396
 397                         if (valid_port(wIndex)) {
 398                                 pdata->overcurrent_changed[wIndex] = 0;
 399                                 pdata->overcurrent_status[wIndex] = 0;
 400                         }
 401
 402                         goto out;
 403
 404                 case USB_PORT_FEAT_OVER_CURRENT:
 405                         dev_dbg(hcd->self.controller,
 406                                 "ClearPortFeature: OVER_CURRENT\n");
 407
 408                         if (valid_port(wIndex))
 409                                 pdata->overcurrent_status[wIndex] = 0;
 410
 411                         goto out;
 412
 413                 case USB_PORT_FEAT_POWER:
 414                         dev_dbg(hcd->self.controller,
 415                                 "ClearPortFeature: POWER\n");
 416
 417                         if (valid_port(wIndex)) {
 418                                 ohci_at91_usb_set_power(pdata, wIndex, 0);
 419                                 return 0;
 420                         }
 421                         break;
 422
 423                 case USB_PORT_FEAT_SUSPEND:
 424                         dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n");
 425                         if (valid_port(wIndex)) {
 426                                 ohci_at91_port_suspend(ohci_at91, 0);
 427                                 return 0;
 428                         }
 429                         break;
 430                 }
 431                 break;
 432         }
 433
 434         ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
 435         if (ret)
 436                 goto out;
 437
 438         switch (typeReq) {
 439         case GetHubDescriptor:
 440
 441                 /* update the hub's descriptor */
 442
 443                 desc = (struct usb_hub_descriptor *)buf;
 444
 445                 dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
 446                         desc->wHubCharacteristics);
 447
 448                 /* remove the old configurations for power-switching, and
 449                  * over-current protection, and insert our new configuration
 450                  */
 451
 452                 desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
 453                 desc->wHubCharacteristics |=
 454                         cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM);
 455
 456                 if (pdata->overcurrent_supported) {
 457                         desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
 458                         desc->wHubCharacteristics |=
 459                                 cpu_to_le16(HUB_CHAR_INDV_PORT_OCPM);
 460                 }
 461
 462                 dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
 463                         desc->wHubCharacteristics);
 464
 465                 return ret;
 466
 467         case GetPortStatus:
 468                 /* check port status */
 469
 470                 dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
 471
 472                 if (valid_port(wIndex)) {
 473                         if (!ohci_at91_usb_get_power(pdata, wIndex))
 474                                 *data &= ~cpu_to_le32(RH_PS_PPS);
 475
 476                         if (pdata->overcurrent_changed[wIndex])
 477                                 *data |= cpu_to_le32(RH_PS_OCIC);
 478
 479                         if (pdata->overcurrent_status[wIndex])
 480                                 *data |= cpu_to_le32(RH_PS_POCI);
 481                 }
 482         }
 483
 484  out:
 485         return ret;
 486 }
 487
 488 /*-------------------------------------------------------------------------*/
 489
 490 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
 491 {
 492         struct platform_device *pdev = data;
 493         struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
 494         int val, port;
 495
 496         /* From the GPIO notifying the over-current situation, find
 497          * out the corresponding port */
 498         at91_for_each_port(port) {
 499                 if (gpiod_to_irq(pdata->overcurrent_pin[port]) == irq)
 500                         break;
 501         }
 502
 503         if (port == AT91_MAX_USBH_PORTS) {
 504                 dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
 505                 return IRQ_HANDLED;
 506         }
 507
 508         val = gpiod_get_value(pdata->overcurrent_pin[port]);
 509
 510         /* When notified of an over-current situation, disable power
 511            on the corresponding port, and mark this port in
 512            over-current. */
 513         if (!val) {
 514                 ohci_at91_usb_set_power(pdata, port, 0);
 515                 pdata->overcurrent_status[port]  = 1;
 516                 pdata->overcurrent_changed[port] = 1;
 517         }
 518
 519         dev_dbg(& pdev->dev, "overcurrent situation %s\n",
 520                 val ? "exited" : "notified");
 521
 522         return IRQ_HANDLED;
 523 }
 524
 525 static const struct of_device_id at91_ohci_dt_ids[] = {
 526         { .compatible = "atmel,at91rm9200-ohci" },
 527         { /* sentinel */ }
 528 };
 529
 530 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
 531
 532 /*-------------------------------------------------------------------------*/
 533
 534 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
 535 {
 536         struct device_node *np = pdev->dev.of_node;
 537         struct at91_usbh_data   *pdata;
 538         int                     i;
 539         int                     ret;
 540         int                     err;
 541         u32                     ports;
 542
 543         /* Right now device-tree probed devices don't get dma_mask set.
 544          * Since shared usb code relies on it, set it here for now.
 545          * Once we have dma capability bindings this can go away.
 546          */
 547         ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 548         if (ret)
 549                 return ret;
 550
 551         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 552         if (!pdata)
 553                 return -ENOMEM;
 554
 555         pdev->dev.platform_data = pdata;
 556
 557         if (!of_property_read_u32(np, "num-ports", &ports))
 558                 pdata->ports = ports;
 559
 560         at91_for_each_port(i) {
 561                 if (i >= pdata->ports)
 562                         break;
 563
 564                 pdata->vbus_pin[i] =
 565                         devm_gpiod_get_index_optional(&pdev->dev, "atmel,vbus",
 566                                                       i, GPIOD_OUT_HIGH);
 567                 if (IS_ERR(pdata->vbus_pin[i])) {
 568                         err = PTR_ERR(pdata->vbus_pin[i]);
 569                         dev_err(&pdev->dev, "unable to claim gpio \"vbus\": %d\n", err);
 570                         continue;
 571                 }
 572         }
 573
 574         at91_for_each_port(i) {
 575                 if (i >= pdata->ports)
 576                         break;
 577
 578                 pdata->overcurrent_pin[i] =
 579                         devm_gpiod_get_index_optional(&pdev->dev, "atmel,oc",
 580                                                       i, GPIOD_IN);
 581                 if (!pdata->overcurrent_pin[i])
 582                         continue;
 583                 if (IS_ERR(pdata->overcurrent_pin[i])) {
 584                         err = PTR_ERR(pdata->overcurrent_pin[i]);
 585                         dev_err(&pdev->dev, "unable to claim gpio \"overcurrent\": %d\n", err);
 586                         continue;
 587                 }
 588
 589                 ret = devm_request_irq(&pdev->dev,
 590                                        gpiod_to_irq(pdata->overcurrent_pin[i]),
 591                                        ohci_hcd_at91_overcurrent_irq,
 592                                        IRQF_SHARED,
 593                                        "ohci_overcurrent", pdev);
 594                 if (ret)
 595                         dev_info(&pdev->dev, "failed to request gpio \"overcurrent\" IRQ\n");
 596         }
 597
 598         device_init_wakeup(&pdev->dev, 1);
 599         return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
 600 }
 601
 602 static void ohci_hcd_at91_drv_remove(struct platform_device *pdev)
 603 {
 604         struct at91_usbh_data   *pdata = dev_get_platdata(&pdev->dev);
 605         int                     i;
 606
 607         if (pdata) {
 608                 at91_for_each_port(i)
 609                         ohci_at91_usb_set_power(pdata, i, 0);
 610         }
 611
 612         device_init_wakeup(&pdev->dev, 0);
 613         usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
 614 }
 615
 616 static int __maybe_unused
 617 ohci_hcd_at91_drv_suspend(struct device *dev)
 618 {
 619         struct usb_hcd  *hcd = dev_get_drvdata(dev);
 620         struct ohci_hcd *ohci = hcd_to_ohci(hcd);
 621         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 622         int             ret;
 623
 624         /*
 625          * Disable wakeup if we are going to sleep with slow clock mode
 626          * enabled.
 627          */
 628         ohci_at91->wakeup = device_may_wakeup(dev)
 629                         && !at91_suspend_entering_slow_clock();
 630
 631         if (ohci_at91->wakeup)
 632                 enable_irq_wake(hcd->irq);
 633
 634         ret = ohci_suspend(hcd, ohci_at91->wakeup);
 635         if (ret) {
 636                 if (ohci_at91->wakeup)
 637                         disable_irq_wake(hcd->irq);
 638                 return ret;
 639         }
 640         /*
 641          * The integrated transceivers seem unable to notice disconnect,
 642          * reconnect, or wakeup without the 48 MHz clock active.  so for
 643          * correctness, always discard connection state (using reset).
 644          *
 645          * REVISIT: some boards will be able to turn VBUS off...
 646          */
 647         if (!ohci_at91->wakeup) {
 648                 ohci->rh_state = OHCI_RH_HALTED;
 649
 650                 /* flush the writes */
 651                 (void) ohci_readl (ohci, &ohci->regs->control);
 652                 msleep(1);
 653                 ohci_at91_port_suspend(ohci_at91, 1);
 654                 at91_stop_clock(ohci_at91);
 655         } else {
 656                 ohci_at91_port_suspend(ohci_at91, 1);
 657         }
 658
 659         return ret;
 660 }
 661
 662 static int __maybe_unused
 663 ohci_hcd_at91_drv_resume(struct device *dev)
 664 {
 665         struct usb_hcd  *hcd = dev_get_drvdata(dev);
 666         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 667
 668         ohci_at91_port_suspend(ohci_at91, 0);
 669
 670         if (ohci_at91->wakeup)
 671                 disable_irq_wake(hcd->irq);
 672         else
 673                 at91_start_clock(ohci_at91);
 674
 675         /*
 676          * According to the comment in ohci_hcd_at91_drv_suspend()
 677          * we need to do a reset if the 48Mhz clock was stopped,
 678          * that is, if ohci_at91->wakeup is clear. Tell ohci_resume()
 679          * to reset in this case by setting its "hibernated" flag.
 680          */
 681         ohci_resume(hcd, !ohci_at91->wakeup);
 682
 683         return 0;
 684 }
 685
 686 static SIMPLE_DEV_PM_OPS(ohci_hcd_at91_pm_ops, ohci_hcd_at91_drv_suspend,
 687                                         ohci_hcd_at91_drv_resume);
 688
 689 static struct platform_driver ohci_hcd_at91_driver = {
 690         .probe          = ohci_hcd_at91_drv_probe,
 691         .remove_new     = ohci_hcd_at91_drv_remove,
 692         .shutdown       = usb_hcd_platform_shutdown,
 693         .driver         = {
 694                 .name   = "at91_ohci",
 695                 .pm     = &ohci_hcd_at91_pm_ops,
 696                 .of_match_table = at91_ohci_dt_ids,
 697         },
 698 };
 699
 700 static int __init ohci_at91_init(void)
 701 {
 702         if (usb_disabled())
 703                 return -ENODEV;
 704
 705         ohci_init_driver(&ohci_at91_hc_driver, &ohci_at91_drv_overrides);
 706
 707         /*
 708          * The Atmel HW has some unusual quirks, which require Atmel-specific
 709          * workarounds. We override certain hc_driver functions here to
 710          * achieve that. We explicitly do not enhance ohci_driver_overrides to
 711          * allow this more easily, since this is an unusual case, and we don't
 712          * want to encourage others to override these functions by making it
 713          * too easy.
 714          */
 715
 716         ohci_at91_hc_driver.hub_status_data     = ohci_at91_hub_status_data;
 717         ohci_at91_hc_driver.hub_control         = ohci_at91_hub_control;
 718
 719         return platform_driver_register(&ohci_hcd_at91_driver);
 720 }
 721 module_init(ohci_at91_init);
 722
 723 static void __exit ohci_at91_cleanup(void)
 724 {
 725         platform_driver_unregister(&ohci_hcd_at91_driver);
 726 }
 727 module_exit(ohci_at91_cleanup);
 728
 729 MODULE_DESCRIPTION(DRIVER_DESC);
 730 MODULE_LICENSE("GPL");
 731 MODULE_ALIAS("platform:at91_ohci");