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 <[email protected]>
   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 const char hcd_name[] = "ohci-atmel";
  66
  67 static struct hc_driver __read_mostly ohci_at91_hc_driver;
  68
  69 static const struct ohci_driver_overrides ohci_at91_drv_overrides __initconst = {
  70         .extra_priv_size = sizeof(struct ohci_at91_priv),
  71 };
  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_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 121
 122         dev_dbg(&pdev->dev, "stop\n");
 123
 124         /*
 125          * Put the USB host controller into reset.
 126          */
 127         usb_hcd_platform_shutdown(pdev);
 128
 129         /*
 130          * Stop the USB clocks.
 131          */
 132         at91_stop_clock(ohci_at91);
 133 }
 134
 135
 136 /*-------------------------------------------------------------------------*/
 137
 138 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
 139
 140 static u32 at91_dt_suspend_smc(struct device *dev)
 141 {
 142         u32 suspend_smc_id;
 143
 144         if (!dev->of_node)
 145                 return 0;
 146
 147         if (of_property_read_u32(dev->of_node, "microchip,suspend-smc-id", &suspend_smc_id))
 148                 return 0;
 149
 150         return suspend_smc_id;
 151 }
 152
 153 static struct regmap *at91_dt_syscon_sfr(void)
 154 {
 155         struct regmap *regmap;
 156
 157         regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");
 158         if (IS_ERR(regmap)) {
 159                 regmap = syscon_regmap_lookup_by_compatible("microchip,sam9x60-sfr");
 160                 if (IS_ERR(regmap))
 161                         regmap = NULL;
 162         }
 163
 164         return regmap;
 165 }
 166
 167 /* configure so an HC device and id are always provided */
 168 /* always called with process context; sleeping is OK */
 169
 170
 171 /*
 172  * usb_hcd_at91_probe - initialize AT91-based HCDs
 173  * @driver:     Pointer to hc driver instance
 174  * @pdev:       USB controller to probe
 175  *
 176  * Context: task context, might sleep
 177  *
 178  * Allocates basic resources for this USB host controller, and
 179  * then invokes the start() method for the HCD associated with it
 180  * through the hotplug entry's driver_data.
 181  */
 182 static int usb_hcd_at91_probe(const struct hc_driver *driver,
 183                         struct platform_device *pdev)
 184 {
 185         struct at91_usbh_data *board;
 186         struct ohci_hcd *ohci;
 187         int retval;
 188         struct usb_hcd *hcd;
 189         struct ohci_at91_priv *ohci_at91;
 190         struct device *dev = &pdev->dev;
 191         struct resource *res;
 192         int irq;
 193
 194         irq = platform_get_irq(pdev, 0);
 195         if (irq < 0) {
 196                 dev_dbg(dev, "hcd probe: missing irq resource\n");
 197                 return irq;
 198         }
 199
 200         hcd = usb_create_hcd(driver, dev, "at91");
 201         if (!hcd)
 202                 return -ENOMEM;
 203         ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 204
 205         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 206         hcd->regs = devm_ioremap_resource(dev, res);
 207         if (IS_ERR(hcd->regs)) {
 208                 retval = PTR_ERR(hcd->regs);
 209                 goto err;
 210         }
 211         hcd->rsrc_start = res->start;
 212         hcd->rsrc_len = resource_size(res);
 213
 214         ohci_at91->iclk = devm_clk_get(dev, "ohci_clk");
 215         if (IS_ERR(ohci_at91->iclk)) {
 216                 dev_err(dev, "failed to get ohci_clk\n");
 217                 retval = PTR_ERR(ohci_at91->iclk);
 218                 goto err;
 219         }
 220         ohci_at91->fclk = devm_clk_get(dev, "uhpck");
 221         if (IS_ERR(ohci_at91->fclk)) {
 222                 dev_err(dev, "failed to get uhpck\n");
 223                 retval = PTR_ERR(ohci_at91->fclk);
 224                 goto err;
 225         }
 226         ohci_at91->hclk = devm_clk_get(dev, "hclk");
 227         if (IS_ERR(ohci_at91->hclk)) {
 228                 dev_err(dev, "failed to get hclk\n");
 229                 retval = PTR_ERR(ohci_at91->hclk);
 230                 goto err;
 231         }
 232
 233         ohci_at91->suspend_smc_id = at91_dt_suspend_smc(dev);
 234         if (!ohci_at91->suspend_smc_id)  {
 235                 dev_dbg(dev, "failed to find sfr suspend smc id, using regmap\n");
 236                 ohci_at91->sfr_regmap = at91_dt_syscon_sfr();
 237                 if (!ohci_at91->sfr_regmap)
 238                         dev_dbg(dev, "failed to find sfr node\n");
 239         }
 240
 241         board = hcd->self.controller->platform_data;
 242         ohci = hcd_to_ohci(hcd);
 243         ohci->num_ports = board->ports;
 244         at91_start_hc(pdev);
 245
 246         /*
 247          * The RemoteWakeupConnected bit has to be set explicitly
 248          * before calling ohci_run. The reset value of this bit is 0.
 249          */
 250         ohci->hc_control = OHCI_CTRL_RWC;
 251
 252         retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
 253         if (retval == 0) {
 254                 device_wakeup_enable(hcd->self.controller);
 255                 return retval;
 256         }
 257
 258         /* Error handling */
 259         at91_stop_hc(pdev);
 260
 261  err:
 262         usb_put_hcd(hcd);
 263         return retval;
 264 }
 265
 266
 267 /* may be called with controller, bus, and devices active */
 268
 269 /*
 270  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
 271  * @hcd:        USB controller to remove
 272  * @pdev:       Platform device required for cleanup
 273  *
 274  * Context: task context, might sleep
 275  *
 276  * Reverses the effect of usb_hcd_at91_probe(), first invoking
 277  * the HCD's stop() method.  It is always called from a thread
 278  * context, "rmmod" or something similar.
 279  */
 280 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
 281                                 struct platform_device *pdev)
 282 {
 283         usb_remove_hcd(hcd);
 284         at91_stop_hc(pdev);
 285         usb_put_hcd(hcd);
 286 }
 287
 288 /*-------------------------------------------------------------------------*/
 289 static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
 290 {
 291         if (!valid_port(port))
 292                 return;
 293
 294         gpiod_set_value(pdata->vbus_pin[port], enable);
 295 }
 296
 297 static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
 298 {
 299         if (!valid_port(port))
 300                 return -EINVAL;
 301
 302         return gpiod_get_value(pdata->vbus_pin[port]);
 303 }
 304
 305 /*
 306  * Update the status data from the hub with the over-current indicator change.
 307  */
 308 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
 309 {
 310         struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
 311         int length = ohci_hub_status_data(hcd, buf);
 312         int port;
 313
 314         at91_for_each_port(port) {
 315                 if (pdata->overcurrent_changed[port]) {
 316                         if (!length)
 317                                 length = 1;
 318                         buf[0] |= 1 << (port + 1);
 319                 }
 320         }
 321
 322         return length;
 323 }
 324
 325 static int ohci_at91_port_suspend(struct ohci_at91_priv *ohci_at91, u8 set)
 326 {
 327         struct regmap *regmap = ohci_at91->sfr_regmap;
 328         u32 regval;
 329         int ret;
 330
 331         if (ohci_at91->suspend_smc_id) {
 332                 struct arm_smccc_res res;
 333
 334                 arm_smccc_smc(ohci_at91->suspend_smc_id, set, 0, 0, 0, 0, 0, 0, &res);
 335                 if (res.a0)
 336                         return -EINVAL;
 337         } else if (regmap) {
 338                 ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);
 339                 if (ret)
 340                         return ret;
 341
 342                 if (set)
 343                         regval |= AT91_OHCIICR_USB_SUSPEND;
 344                 else
 345                         regval &= ~AT91_OHCIICR_USB_SUSPEND;
 346
 347                 regmap_write(regmap, AT91_SFR_OHCIICR, regval);
 348         }
 349
 350         return 0;
 351 }
 352
 353 /*
 354  * Look at the control requests to the root hub and see if we need to override.
 355  */
 356 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
 357                                  u16 wIndex, char *buf, u16 wLength)
 358 {
 359         struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
 360         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 361         struct usb_hub_descriptor *desc;
 362         int ret = -EINVAL;
 363         u32 *data = (u32 *)buf;
 364
 365         dev_dbg(hcd->self.controller,
 366                 "ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
 367                 hcd, typeReq, wValue, wIndex, buf, wLength);
 368
 369         wIndex--;
 370
 371         switch (typeReq) {
 372         case SetPortFeature:
 373                 switch (wValue) {
 374                 case USB_PORT_FEAT_POWER:
 375                         dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
 376                         if (valid_port(wIndex)) {
 377                                 ohci_at91_usb_set_power(pdata, wIndex, 1);
 378                                 ret = 0;
 379                         }
 380
 381                         goto out;
 382
 383                 case USB_PORT_FEAT_SUSPEND:
 384                         dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n");
 385                         if (valid_port(wIndex)) {
 386                                 ohci_at91_port_suspend(ohci_at91, 1);
 387                                 return 0;
 388                         }
 389                         break;
 390                 }
 391                 break;
 392
 393         case ClearPortFeature:
 394                 switch (wValue) {
 395                 case USB_PORT_FEAT_C_OVER_CURRENT:
 396                         dev_dbg(hcd->self.controller,
 397                                 "ClearPortFeature: C_OVER_CURRENT\n");
 398
 399                         if (valid_port(wIndex)) {
 400                                 pdata->overcurrent_changed[wIndex] = 0;
 401                                 pdata->overcurrent_status[wIndex] = 0;
 402                         }
 403
 404                         goto out;
 405
 406                 case USB_PORT_FEAT_OVER_CURRENT:
 407                         dev_dbg(hcd->self.controller,
 408                                 "ClearPortFeature: OVER_CURRENT\n");
 409
 410                         if (valid_port(wIndex))
 411                                 pdata->overcurrent_status[wIndex] = 0;
 412
 413                         goto out;
 414
 415                 case USB_PORT_FEAT_POWER:
 416                         dev_dbg(hcd->self.controller,
 417                                 "ClearPortFeature: POWER\n");
 418
 419                         if (valid_port(wIndex)) {
 420                                 ohci_at91_usb_set_power(pdata, wIndex, 0);
 421                                 return 0;
 422                         }
 423                         break;
 424
 425                 case USB_PORT_FEAT_SUSPEND:
 426                         dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n");
 427                         if (valid_port(wIndex)) {
 428                                 ohci_at91_port_suspend(ohci_at91, 0);
 429                                 return 0;
 430                         }
 431                         break;
 432                 }
 433                 break;
 434         }
 435
 436         ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
 437         if (ret)
 438                 goto out;
 439
 440         switch (typeReq) {
 441         case GetHubDescriptor:
 442
 443                 /* update the hub's descriptor */
 444
 445                 desc = (struct usb_hub_descriptor *)buf;
 446
 447                 dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
 448                         desc->wHubCharacteristics);
 449
 450                 /* remove the old configurations for power-switching, and
 451                  * over-current protection, and insert our new configuration
 452                  */
 453
 454                 desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
 455                 desc->wHubCharacteristics |=
 456                         cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM);
 457
 458                 if (pdata->overcurrent_supported) {
 459                         desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
 460                         desc->wHubCharacteristics |=
 461                                 cpu_to_le16(HUB_CHAR_INDV_PORT_OCPM);
 462                 }
 463
 464                 dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
 465                         desc->wHubCharacteristics);
 466
 467                 return ret;
 468
 469         case GetPortStatus:
 470                 /* check port status */
 471
 472                 dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
 473
 474                 if (valid_port(wIndex)) {
 475                         if (!ohci_at91_usb_get_power(pdata, wIndex))
 476                                 *data &= ~cpu_to_le32(RH_PS_PPS);
 477
 478                         if (pdata->overcurrent_changed[wIndex])
 479                                 *data |= cpu_to_le32(RH_PS_OCIC);
 480
 481                         if (pdata->overcurrent_status[wIndex])
 482                                 *data |= cpu_to_le32(RH_PS_POCI);
 483                 }
 484         }
 485
 486  out:
 487         return ret;
 488 }
 489
 490 /*-------------------------------------------------------------------------*/
 491
 492 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
 493 {
 494         struct platform_device *pdev = data;
 495         struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
 496         int val, port;
 497
 498         /* From the GPIO notifying the over-current situation, find
 499          * out the corresponding port */
 500         at91_for_each_port(port) {
 501                 if (gpiod_to_irq(pdata->overcurrent_pin[port]) == irq)
 502                         break;
 503         }
 504
 505         if (port == AT91_MAX_USBH_PORTS) {
 506                 dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
 507                 return IRQ_HANDLED;
 508         }
 509
 510         val = gpiod_get_value(pdata->overcurrent_pin[port]);
 511
 512         /* When notified of an over-current situation, disable power
 513            on the corresponding port, and mark this port in
 514            over-current. */
 515         if (!val) {
 516                 ohci_at91_usb_set_power(pdata, port, 0);
 517                 pdata->overcurrent_status[port]  = 1;
 518                 pdata->overcurrent_changed[port] = 1;
 519         }
 520
 521         dev_dbg(& pdev->dev, "overcurrent situation %s\n",
 522                 val ? "exited" : "notified");
 523
 524         return IRQ_HANDLED;
 525 }
 526
 527 static const struct of_device_id at91_ohci_dt_ids[] = {
 528         { .compatible = "atmel,at91rm9200-ohci" },
 529         { /* sentinel */ }
 530 };
 531
 532 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
 533
 534 /*-------------------------------------------------------------------------*/
 535
 536 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
 537 {
 538         struct device_node *np = pdev->dev.of_node;
 539         struct at91_usbh_data   *pdata;
 540         int                     i;
 541         int                     ret;
 542         int                     err;
 543         u32                     ports;
 544
 545         /* Right now device-tree probed devices don't get dma_mask set.
 546          * Since shared usb code relies on it, set it here for now.
 547          * Once we have dma capability bindings this can go away.
 548          */
 549         ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
 550         if (ret)
 551                 return ret;
 552
 553         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
 554         if (!pdata)
 555                 return -ENOMEM;
 556
 557         pdev->dev.platform_data = pdata;
 558
 559         if (!of_property_read_u32(np, "num-ports", &ports))
 560                 pdata->ports = ports;
 561
 562         at91_for_each_port(i) {
 563                 if (i >= pdata->ports)
 564                         break;
 565
 566                 pdata->vbus_pin[i] =
 567                         devm_gpiod_get_index_optional(&pdev->dev, "atmel,vbus",
 568                                                       i, GPIOD_OUT_HIGH);
 569                 if (IS_ERR(pdata->vbus_pin[i])) {
 570                         err = PTR_ERR(pdata->vbus_pin[i]);
 571                         dev_err(&pdev->dev, "unable to claim gpio \"vbus\": %d\n", err);
 572                         continue;
 573                 }
 574         }
 575
 576         at91_for_each_port(i) {
 577                 if (i >= pdata->ports)
 578                         break;
 579
 580                 pdata->overcurrent_pin[i] =
 581                         devm_gpiod_get_index_optional(&pdev->dev, "atmel,oc",
 582                                                       i, GPIOD_IN);
 583                 if (!pdata->overcurrent_pin[i])
 584                         continue;
 585                 if (IS_ERR(pdata->overcurrent_pin[i])) {
 586                         err = PTR_ERR(pdata->overcurrent_pin[i]);
 587                         dev_err(&pdev->dev, "unable to claim gpio \"overcurrent\": %d\n", err);
 588                         continue;
 589                 }
 590
 591                 ret = devm_request_irq(&pdev->dev,
 592                                        gpiod_to_irq(pdata->overcurrent_pin[i]),
 593                                        ohci_hcd_at91_overcurrent_irq,
 594                                        IRQF_SHARED,
 595                                        "ohci_overcurrent", pdev);
 596                 if (ret)
 597                         dev_info(&pdev->dev, "failed to request gpio \"overcurrent\" IRQ\n");
 598         }
 599
 600         device_init_wakeup(&pdev->dev, 1);
 601         return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
 602 }
 603
 604 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
 605 {
 606         struct at91_usbh_data   *pdata = dev_get_platdata(&pdev->dev);
 607         int                     i;
 608
 609         if (pdata) {
 610                 at91_for_each_port(i)
 611                         ohci_at91_usb_set_power(pdata, i, 0);
 612         }
 613
 614         device_init_wakeup(&pdev->dev, 0);
 615         usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
 616         return 0;
 617 }
 618
 619 static int __maybe_unused
 620 ohci_hcd_at91_drv_suspend(struct device *dev)
 621 {
 622         struct usb_hcd  *hcd = dev_get_drvdata(dev);
 623         struct ohci_hcd *ohci = hcd_to_ohci(hcd);
 624         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 625         int             ret;
 626
 627         /*
 628          * Disable wakeup if we are going to sleep with slow clock mode
 629          * enabled.
 630          */
 631         ohci_at91->wakeup = device_may_wakeup(dev)
 632                         && !at91_suspend_entering_slow_clock();
 633
 634         if (ohci_at91->wakeup)
 635                 enable_irq_wake(hcd->irq);
 636
 637         ret = ohci_suspend(hcd, ohci_at91->wakeup);
 638         if (ret) {
 639                 if (ohci_at91->wakeup)
 640                         disable_irq_wake(hcd->irq);
 641                 return ret;
 642         }
 643         /*
 644          * The integrated transceivers seem unable to notice disconnect,
 645          * reconnect, or wakeup without the 48 MHz clock active.  so for
 646          * correctness, always discard connection state (using reset).
 647          *
 648          * REVISIT: some boards will be able to turn VBUS off...
 649          */
 650         if (!ohci_at91->wakeup) {
 651                 ohci->rh_state = OHCI_RH_HALTED;
 652
 653                 /* flush the writes */
 654                 (void) ohci_readl (ohci, &ohci->regs->control);
 655                 msleep(1);
 656                 ohci_at91_port_suspend(ohci_at91, 1);
 657                 at91_stop_clock(ohci_at91);
 658         } else {
 659                 ohci_at91_port_suspend(ohci_at91, 1);
 660         }
 661
 662         return ret;
 663 }
 664
 665 static int __maybe_unused
 666 ohci_hcd_at91_drv_resume(struct device *dev)
 667 {
 668         struct usb_hcd  *hcd = dev_get_drvdata(dev);
 669         struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
 670
 671         ohci_at91_port_suspend(ohci_at91, 0);
 672
 673         if (ohci_at91->wakeup)
 674                 disable_irq_wake(hcd->irq);
 675         else
 676                 at91_start_clock(ohci_at91);
 677
 678         ohci_resume(hcd, false);
 679
 680         return 0;
 681 }
 682
 683 static SIMPLE_DEV_PM_OPS(ohci_hcd_at91_pm_ops, ohci_hcd_at91_drv_suspend,
 684                                         ohci_hcd_at91_drv_resume);
 685
 686 static struct platform_driver ohci_hcd_at91_driver = {
 687         .probe          = ohci_hcd_at91_drv_probe,
 688         .remove         = ohci_hcd_at91_drv_remove,
 689         .shutdown       = usb_hcd_platform_shutdown,
 690         .driver         = {
 691                 .name   = "at91_ohci",
 692                 .pm     = &ohci_hcd_at91_pm_ops,
 693                 .of_match_table = at91_ohci_dt_ids,
 694         },
 695 };
 696
 697 static int __init ohci_at91_init(void)
 698 {
 699         if (usb_disabled())
 700                 return -ENODEV;
 701
 702         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
 703         ohci_init_driver(&ohci_at91_hc_driver, &ohci_at91_drv_overrides);
 704
 705         /*
 706          * The Atmel HW has some unusual quirks, which require Atmel-specific
 707          * workarounds. We override certain hc_driver functions here to
 708          * achieve that. We explicitly do not enhance ohci_driver_overrides to
 709          * allow this more easily, since this is an unusual case, and we don't
 710          * want to encourage others to override these functions by making it
 711          * too easy.
 712          */
 713
 714         ohci_at91_hc_driver.hub_status_data     = ohci_at91_hub_status_data;
 715         ohci_at91_hc_driver.hub_control         = ohci_at91_hub_control;
 716
 717         return platform_driver_register(&ohci_hcd_at91_driver);
 718 }
 719 module_init(ohci_at91_init);
 720
 721 static void __exit ohci_at91_cleanup(void)
 722 {
 723         platform_driver_unregister(&ohci_hcd_at91_driver);
 724 }
 725 module_exit(ohci_at91_cleanup);
 726
 727 MODULE_DESCRIPTION(DRIVER_DESC);
 728 MODULE_LICENSE("GPL");
 729 MODULE_ALIAS("platform:at91_ohci");