xref: /openbmc/linux/drivers/usb/host/ohci-at91.c (revision bc000245)
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 <mach/hardware.h>
28 #include <asm/gpio.h>
29 
30 #include <mach/cpu.h>
31 
32 
33 #include "ohci.h"
34 
35 #define valid_port(index)	((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
36 #define at91_for_each_port(index)	\
37 		for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
38 
39 /* interface, function and usb clocks; sometimes also an AHB clock */
40 static struct clk *iclk, *fclk, *uclk, *hclk;
41 /* interface and function clocks; sometimes also an AHB clock */
42 
43 #define DRIVER_DESC "OHCI Atmel driver"
44 
45 static const char hcd_name[] = "ohci-atmel";
46 
47 static struct hc_driver __read_mostly ohci_at91_hc_driver;
48 static int clocked;
49 static int (*orig_ohci_hub_control)(struct usb_hcd  *hcd, u16 typeReq,
50 			u16 wValue, u16 wIndex, char *buf, u16 wLength);
51 static int (*orig_ohci_hub_status_data)(struct usb_hcd *hcd, char *buf);
52 
53 extern int usb_disabled(void);
54 
55 /*-------------------------------------------------------------------------*/
56 
57 static void at91_start_clock(void)
58 {
59 	if (IS_ENABLED(CONFIG_COMMON_CLK)) {
60 		clk_set_rate(uclk, 48000000);
61 		clk_prepare_enable(uclk);
62 	}
63 	clk_prepare_enable(hclk);
64 	clk_prepare_enable(iclk);
65 	clk_prepare_enable(fclk);
66 	clocked = 1;
67 }
68 
69 static void at91_stop_clock(void)
70 {
71 	clk_disable_unprepare(fclk);
72 	clk_disable_unprepare(iclk);
73 	clk_disable_unprepare(hclk);
74 	if (IS_ENABLED(CONFIG_COMMON_CLK))
75 		clk_disable_unprepare(uclk);
76 	clocked = 0;
77 }
78 
79 static void at91_start_hc(struct platform_device *pdev)
80 {
81 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
82 	struct ohci_regs __iomem *regs = hcd->regs;
83 
84 	dev_dbg(&pdev->dev, "start\n");
85 
86 	/*
87 	 * Start the USB clocks.
88 	 */
89 	at91_start_clock();
90 
91 	/*
92 	 * The USB host controller must remain in reset.
93 	 */
94 	writel(0, &regs->control);
95 }
96 
97 static void at91_stop_hc(struct platform_device *pdev)
98 {
99 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
100 	struct ohci_regs __iomem *regs = hcd->regs;
101 
102 	dev_dbg(&pdev->dev, "stop\n");
103 
104 	/*
105 	 * Put the USB host controller into reset.
106 	 */
107 	writel(0, &regs->control);
108 
109 	/*
110 	 * Stop the USB clocks.
111 	 */
112 	at91_stop_clock();
113 }
114 
115 
116 /*-------------------------------------------------------------------------*/
117 
118 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
119 
120 /* configure so an HC device and id are always provided */
121 /* always called with process context; sleeping is OK */
122 
123 
124 /**
125  * usb_hcd_at91_probe - initialize AT91-based HCDs
126  * Context: !in_interrupt()
127  *
128  * Allocates basic resources for this USB host controller, and
129  * then invokes the start() method for the HCD associated with it
130  * through the hotplug entry's driver_data.
131  */
132 static int usb_hcd_at91_probe(const struct hc_driver *driver,
133 			struct platform_device *pdev)
134 {
135 	struct at91_usbh_data *board;
136 	struct ohci_hcd *ohci;
137 	int retval;
138 	struct usb_hcd *hcd = NULL;
139 
140 	if (pdev->num_resources != 2) {
141 		pr_debug("hcd probe: invalid num_resources");
142 		return -ENODEV;
143 	}
144 
145 	if ((pdev->resource[0].flags != IORESOURCE_MEM)
146 			|| (pdev->resource[1].flags != IORESOURCE_IRQ)) {
147 		pr_debug("hcd probe: invalid resource type\n");
148 		return -ENODEV;
149 	}
150 
151 	hcd = usb_create_hcd(driver, &pdev->dev, "at91");
152 	if (!hcd)
153 		return -ENOMEM;
154 	hcd->rsrc_start = pdev->resource[0].start;
155 	hcd->rsrc_len = resource_size(&pdev->resource[0]);
156 
157 	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
158 		pr_debug("request_mem_region failed\n");
159 		retval = -EBUSY;
160 		goto err1;
161 	}
162 
163 	hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
164 	if (!hcd->regs) {
165 		pr_debug("ioremap failed\n");
166 		retval = -EIO;
167 		goto err2;
168 	}
169 
170 	iclk = clk_get(&pdev->dev, "ohci_clk");
171 	if (IS_ERR(iclk)) {
172 		dev_err(&pdev->dev, "failed to get ohci_clk\n");
173 		retval = PTR_ERR(iclk);
174 		goto err3;
175 	}
176 	fclk = clk_get(&pdev->dev, "uhpck");
177 	if (IS_ERR(fclk)) {
178 		dev_err(&pdev->dev, "failed to get uhpck\n");
179 		retval = PTR_ERR(fclk);
180 		goto err4;
181 	}
182 	hclk = clk_get(&pdev->dev, "hclk");
183 	if (IS_ERR(hclk)) {
184 		dev_err(&pdev->dev, "failed to get hclk\n");
185 		retval = PTR_ERR(hclk);
186 		goto err5;
187 	}
188 	if (IS_ENABLED(CONFIG_COMMON_CLK)) {
189 		uclk = clk_get(&pdev->dev, "usb_clk");
190 		if (IS_ERR(uclk)) {
191 			dev_err(&pdev->dev, "failed to get uclk\n");
192 			retval = PTR_ERR(uclk);
193 			goto err6;
194 		}
195 	}
196 
197 	board = hcd->self.controller->platform_data;
198 	ohci = hcd_to_ohci(hcd);
199 	ohci->num_ports = board->ports;
200 	at91_start_hc(pdev);
201 
202 	retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_SHARED);
203 	if (retval == 0)
204 		return retval;
205 
206 	/* Error handling */
207 	at91_stop_hc(pdev);
208 
209 	if (IS_ENABLED(CONFIG_COMMON_CLK))
210 		clk_put(uclk);
211  err6:
212 	clk_put(hclk);
213  err5:
214 	clk_put(fclk);
215  err4:
216 	clk_put(iclk);
217 
218  err3:
219 	iounmap(hcd->regs);
220 
221  err2:
222 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
223 
224  err1:
225 	usb_put_hcd(hcd);
226 	return retval;
227 }
228 
229 
230 /* may be called with controller, bus, and devices active */
231 
232 /**
233  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
234  * @dev: USB Host Controller being removed
235  * Context: !in_interrupt()
236  *
237  * Reverses the effect of usb_hcd_at91_probe(), first invoking
238  * the HCD's stop() method.  It is always called from a thread
239  * context, "rmmod" or something similar.
240  *
241  */
242 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
243 				struct platform_device *pdev)
244 {
245 	usb_remove_hcd(hcd);
246 	at91_stop_hc(pdev);
247 	iounmap(hcd->regs);
248 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
249 	usb_put_hcd(hcd);
250 
251 	if (IS_ENABLED(CONFIG_COMMON_CLK))
252 		clk_put(uclk);
253 	clk_put(hclk);
254 	clk_put(fclk);
255 	clk_put(iclk);
256 	fclk = iclk = hclk = NULL;
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 = orig_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 /*
305  * Look at the control requests to the root hub and see if we need to override.
306  */
307 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
308 				 u16 wIndex, char *buf, u16 wLength)
309 {
310 	struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
311 	struct usb_hub_descriptor *desc;
312 	int ret = -EINVAL;
313 	u32 *data = (u32 *)buf;
314 
315 	dev_dbg(hcd->self.controller,
316 		"ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
317 		hcd, typeReq, wValue, wIndex, buf, wLength);
318 
319 	wIndex--;
320 
321 	switch (typeReq) {
322 	case SetPortFeature:
323 		if (wValue == USB_PORT_FEAT_POWER) {
324 			dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
325 			if (valid_port(wIndex)) {
326 				ohci_at91_usb_set_power(pdata, wIndex, 1);
327 				ret = 0;
328 			}
329 
330 			goto out;
331 		}
332 		break;
333 
334 	case ClearPortFeature:
335 		switch (wValue) {
336 		case USB_PORT_FEAT_C_OVER_CURRENT:
337 			dev_dbg(hcd->self.controller,
338 				"ClearPortFeature: C_OVER_CURRENT\n");
339 
340 			if (valid_port(wIndex)) {
341 				pdata->overcurrent_changed[wIndex] = 0;
342 				pdata->overcurrent_status[wIndex] = 0;
343 			}
344 
345 			goto out;
346 
347 		case USB_PORT_FEAT_OVER_CURRENT:
348 			dev_dbg(hcd->self.controller,
349 				"ClearPortFeature: OVER_CURRENT\n");
350 
351 			if (valid_port(wIndex))
352 				pdata->overcurrent_status[wIndex] = 0;
353 
354 			goto out;
355 
356 		case USB_PORT_FEAT_POWER:
357 			dev_dbg(hcd->self.controller,
358 				"ClearPortFeature: POWER\n");
359 
360 			if (valid_port(wIndex)) {
361 				ohci_at91_usb_set_power(pdata, wIndex, 0);
362 				return 0;
363 			}
364 		}
365 		break;
366 	}
367 
368 	ret = orig_ohci_hub_control(hcd, typeReq, wValue, wIndex + 1,
369 				buf, wLength);
370 	if (ret)
371 		goto out;
372 
373 	switch (typeReq) {
374 	case GetHubDescriptor:
375 
376 		/* update the hub's descriptor */
377 
378 		desc = (struct usb_hub_descriptor *)buf;
379 
380 		dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
381 			desc->wHubCharacteristics);
382 
383 		/* remove the old configurations for power-switching, and
384 		 * over-current protection, and insert our new configuration
385 		 */
386 
387 		desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
388 		desc->wHubCharacteristics |= cpu_to_le16(0x0001);
389 
390 		if (pdata->overcurrent_supported) {
391 			desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
392 			desc->wHubCharacteristics |=  cpu_to_le16(0x0008|0x0001);
393 		}
394 
395 		dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
396 			desc->wHubCharacteristics);
397 
398 		return ret;
399 
400 	case GetPortStatus:
401 		/* check port status */
402 
403 		dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
404 
405 		if (valid_port(wIndex)) {
406 			if (!ohci_at91_usb_get_power(pdata, wIndex))
407 				*data &= ~cpu_to_le32(RH_PS_PPS);
408 
409 			if (pdata->overcurrent_changed[wIndex])
410 				*data |= cpu_to_le32(RH_PS_OCIC);
411 
412 			if (pdata->overcurrent_status[wIndex])
413 				*data |= cpu_to_le32(RH_PS_POCI);
414 		}
415 	}
416 
417  out:
418 	return ret;
419 }
420 
421 /*-------------------------------------------------------------------------*/
422 
423 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
424 {
425 	struct platform_device *pdev = data;
426 	struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
427 	int val, gpio, port;
428 
429 	/* From the GPIO notifying the over-current situation, find
430 	 * out the corresponding port */
431 	at91_for_each_port(port) {
432 		if (gpio_is_valid(pdata->overcurrent_pin[port]) &&
433 				gpio_to_irq(pdata->overcurrent_pin[port]) == irq) {
434 			gpio = pdata->overcurrent_pin[port];
435 			break;
436 		}
437 	}
438 
439 	if (port == AT91_MAX_USBH_PORTS) {
440 		dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
441 		return IRQ_HANDLED;
442 	}
443 
444 	val = gpio_get_value(gpio);
445 
446 	/* When notified of an over-current situation, disable power
447 	   on the corresponding port, and mark this port in
448 	   over-current. */
449 	if (!val) {
450 		ohci_at91_usb_set_power(pdata, port, 0);
451 		pdata->overcurrent_status[port]  = 1;
452 		pdata->overcurrent_changed[port] = 1;
453 	}
454 
455 	dev_dbg(& pdev->dev, "overcurrent situation %s\n",
456 		val ? "exited" : "notified");
457 
458 	return IRQ_HANDLED;
459 }
460 
461 #ifdef CONFIG_OF
462 static const struct of_device_id at91_ohci_dt_ids[] = {
463 	{ .compatible = "atmel,at91rm9200-ohci" },
464 	{ /* sentinel */ }
465 };
466 
467 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
468 
469 static int ohci_at91_of_init(struct platform_device *pdev)
470 {
471 	struct device_node *np = pdev->dev.of_node;
472 	int i, gpio, ret;
473 	enum of_gpio_flags flags;
474 	struct at91_usbh_data	*pdata;
475 	u32 ports;
476 
477 	if (!np)
478 		return 0;
479 
480 	/* Right now device-tree probed devices don't get dma_mask set.
481 	 * Since shared usb code relies on it, set it here for now.
482 	 * Once we have dma capability bindings this can go away.
483 	 */
484 	ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
485 	if (ret)
486 		return ret;
487 
488 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
489 	if (!pdata)
490 		return -ENOMEM;
491 
492 	if (!of_property_read_u32(np, "num-ports", &ports))
493 		pdata->ports = ports;
494 
495 	at91_for_each_port(i) {
496 		gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i, &flags);
497 		pdata->vbus_pin[i] = gpio;
498 		if (!gpio_is_valid(gpio))
499 			continue;
500 		pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
501 	}
502 
503 	at91_for_each_port(i)
504 		pdata->overcurrent_pin[i] =
505 			of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);
506 
507 	pdev->dev.platform_data = pdata;
508 
509 	return 0;
510 }
511 #else
512 static int ohci_at91_of_init(struct platform_device *pdev)
513 {
514 	return 0;
515 }
516 #endif
517 
518 /*-------------------------------------------------------------------------*/
519 
520 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
521 {
522 	struct at91_usbh_data	*pdata;
523 	int			i;
524 	int			gpio;
525 	int			ret;
526 
527 	ret = ohci_at91_of_init(pdev);
528 	if (ret)
529 		return ret;
530 
531 	pdata = dev_get_platdata(&pdev->dev);
532 
533 	if (pdata) {
534 		at91_for_each_port(i) {
535 			/*
536 			 * do not configure PIO if not in relation with
537 			 * real USB port on board
538 			 */
539 			if (i >= pdata->ports) {
540 				pdata->vbus_pin[i] = -EINVAL;
541 				pdata->overcurrent_pin[i] = -EINVAL;
542 				break;
543 			}
544 
545 			if (!gpio_is_valid(pdata->vbus_pin[i]))
546 				continue;
547 			gpio = pdata->vbus_pin[i];
548 
549 			ret = gpio_request(gpio, "ohci_vbus");
550 			if (ret) {
551 				dev_err(&pdev->dev,
552 					"can't request vbus gpio %d\n", gpio);
553 				continue;
554 			}
555 			ret = gpio_direction_output(gpio,
556 						!pdata->vbus_pin_active_low[i]);
557 			if (ret) {
558 				dev_err(&pdev->dev,
559 					"can't put vbus gpio %d as output %d\n",
560 					gpio, !pdata->vbus_pin_active_low[i]);
561 				gpio_free(gpio);
562 				continue;
563 			}
564 
565 			ohci_at91_usb_set_power(pdata, i, 1);
566 		}
567 
568 		at91_for_each_port(i) {
569 			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
570 				continue;
571 			gpio = pdata->overcurrent_pin[i];
572 
573 			ret = gpio_request(gpio, "ohci_overcurrent");
574 			if (ret) {
575 				dev_err(&pdev->dev,
576 					"can't request overcurrent gpio %d\n",
577 					gpio);
578 				continue;
579 			}
580 
581 			ret = gpio_direction_input(gpio);
582 			if (ret) {
583 				dev_err(&pdev->dev,
584 					"can't configure overcurrent gpio %d as input\n",
585 					gpio);
586 				gpio_free(gpio);
587 				continue;
588 			}
589 
590 			ret = request_irq(gpio_to_irq(gpio),
591 					  ohci_hcd_at91_overcurrent_irq,
592 					  IRQF_SHARED, "ohci_overcurrent", pdev);
593 			if (ret) {
594 				gpio_free(gpio);
595 				dev_err(&pdev->dev,
596 					"can't get gpio IRQ for overcurrent\n");
597 			}
598 		}
599 	}
600 
601 	device_init_wakeup(&pdev->dev, 1);
602 	return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
603 }
604 
605 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
606 {
607 	struct at91_usbh_data	*pdata = dev_get_platdata(&pdev->dev);
608 	int			i;
609 
610 	if (pdata) {
611 		at91_for_each_port(i) {
612 			if (!gpio_is_valid(pdata->vbus_pin[i]))
613 				continue;
614 			ohci_at91_usb_set_power(pdata, i, 0);
615 			gpio_free(pdata->vbus_pin[i]);
616 		}
617 
618 		at91_for_each_port(i) {
619 			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
620 				continue;
621 			free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
622 			gpio_free(pdata->overcurrent_pin[i]);
623 		}
624 	}
625 
626 	device_init_wakeup(&pdev->dev, 0);
627 	usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
628 	return 0;
629 }
630 
631 #ifdef CONFIG_PM
632 
633 static int
634 ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
635 {
636 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
637 	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
638 
639 	if (device_may_wakeup(&pdev->dev))
640 		enable_irq_wake(hcd->irq);
641 
642 	/*
643 	 * The integrated transceivers seem unable to notice disconnect,
644 	 * reconnect, or wakeup without the 48 MHz clock active.  so for
645 	 * correctness, always discard connection state (using reset).
646 	 *
647 	 * REVISIT: some boards will be able to turn VBUS off...
648 	 */
649 	if (at91_suspend_entering_slow_clock()) {
650 		ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
651 		ohci->hc_control &= OHCI_CTRL_RWC;
652 		ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
653 		ohci->rh_state = OHCI_RH_HALTED;
654 
655 		/* flush the writes */
656 		(void) ohci_readl (ohci, &ohci->regs->control);
657 		at91_stop_clock();
658 	}
659 
660 	return 0;
661 }
662 
663 static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
664 {
665 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
666 
667 	if (device_may_wakeup(&pdev->dev))
668 		disable_irq_wake(hcd->irq);
669 
670 	if (!clocked)
671 		at91_start_clock();
672 
673 	ohci_resume(hcd, false);
674 	return 0;
675 }
676 #else
677 #define ohci_hcd_at91_drv_suspend NULL
678 #define ohci_hcd_at91_drv_resume  NULL
679 #endif
680 
681 static struct platform_driver ohci_hcd_at91_driver = {
682 	.probe		= ohci_hcd_at91_drv_probe,
683 	.remove		= ohci_hcd_at91_drv_remove,
684 	.shutdown	= usb_hcd_platform_shutdown,
685 	.suspend	= ohci_hcd_at91_drv_suspend,
686 	.resume		= ohci_hcd_at91_drv_resume,
687 	.driver		= {
688 		.name	= "at91_ohci",
689 		.owner	= THIS_MODULE,
690 		.of_match_table	= of_match_ptr(at91_ohci_dt_ids),
691 	},
692 };
693 
694 static int __init ohci_at91_init(void)
695 {
696 	if (usb_disabled())
697 		return -ENODEV;
698 
699 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
700 	ohci_init_driver(&ohci_at91_hc_driver, NULL);
701 
702 	/*
703 	 * The Atmel HW has some unusual quirks, which require Atmel-specific
704 	 * workarounds. We override certain hc_driver functions here to
705 	 * achieve that. We explicitly do not enhance ohci_driver_overrides to
706 	 * allow this more easily, since this is an unusual case, and we don't
707 	 * want to encourage others to override these functions by making it
708 	 * too easy.
709 	 */
710 
711 	orig_ohci_hub_control = ohci_at91_hc_driver.hub_control;
712 	orig_ohci_hub_status_data = ohci_at91_hc_driver.hub_status_data;
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");
730