xref: /linux/drivers/usb/host/ohci-at91.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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 	struct device *dev = &pdev->dev;
140 	struct resource *res;
141 	int irq;
142 
143 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
144 	if (!res) {
145 		dev_dbg(dev, "hcd probe: missing memory resource\n");
146 		return -ENXIO;
147 	}
148 
149 	irq = platform_get_irq(pdev, 0);
150 	if (irq < 0) {
151 		dev_dbg(dev, "hcd probe: missing irq resource\n");
152 		return irq;
153 	}
154 
155 	hcd = usb_create_hcd(driver, &pdev->dev, "at91");
156 	if (!hcd)
157 		return -ENOMEM;
158 	hcd->rsrc_start = res->start;
159 	hcd->rsrc_len = resource_size(res);
160 
161 	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
162 		pr_debug("request_mem_region failed\n");
163 		retval = -EBUSY;
164 		goto err1;
165 	}
166 
167 	hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
168 	if (!hcd->regs) {
169 		pr_debug("ioremap failed\n");
170 		retval = -EIO;
171 		goto err2;
172 	}
173 
174 	iclk = clk_get(&pdev->dev, "ohci_clk");
175 	if (IS_ERR(iclk)) {
176 		dev_err(&pdev->dev, "failed to get ohci_clk\n");
177 		retval = PTR_ERR(iclk);
178 		goto err3;
179 	}
180 	fclk = clk_get(&pdev->dev, "uhpck");
181 	if (IS_ERR(fclk)) {
182 		dev_err(&pdev->dev, "failed to get uhpck\n");
183 		retval = PTR_ERR(fclk);
184 		goto err4;
185 	}
186 	hclk = clk_get(&pdev->dev, "hclk");
187 	if (IS_ERR(hclk)) {
188 		dev_err(&pdev->dev, "failed to get hclk\n");
189 		retval = PTR_ERR(hclk);
190 		goto err5;
191 	}
192 	if (IS_ENABLED(CONFIG_COMMON_CLK)) {
193 		uclk = clk_get(&pdev->dev, "usb_clk");
194 		if (IS_ERR(uclk)) {
195 			dev_err(&pdev->dev, "failed to get uclk\n");
196 			retval = PTR_ERR(uclk);
197 			goto err6;
198 		}
199 	}
200 
201 	board = hcd->self.controller->platform_data;
202 	ohci = hcd_to_ohci(hcd);
203 	ohci->num_ports = board->ports;
204 	at91_start_hc(pdev);
205 
206 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
207 	if (retval == 0)
208 		return retval;
209 
210 	/* Error handling */
211 	at91_stop_hc(pdev);
212 
213 	if (IS_ENABLED(CONFIG_COMMON_CLK))
214 		clk_put(uclk);
215  err6:
216 	clk_put(hclk);
217  err5:
218 	clk_put(fclk);
219  err4:
220 	clk_put(iclk);
221 
222  err3:
223 	iounmap(hcd->regs);
224 
225  err2:
226 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
227 
228  err1:
229 	usb_put_hcd(hcd);
230 	return retval;
231 }
232 
233 
234 /* may be called with controller, bus, and devices active */
235 
236 /**
237  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
238  * @dev: USB Host Controller being removed
239  * Context: !in_interrupt()
240  *
241  * Reverses the effect of usb_hcd_at91_probe(), first invoking
242  * the HCD's stop() method.  It is always called from a thread
243  * context, "rmmod" or something similar.
244  *
245  */
246 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
247 				struct platform_device *pdev)
248 {
249 	usb_remove_hcd(hcd);
250 	at91_stop_hc(pdev);
251 	iounmap(hcd->regs);
252 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
253 	usb_put_hcd(hcd);
254 
255 	if (IS_ENABLED(CONFIG_COMMON_CLK))
256 		clk_put(uclk);
257 	clk_put(hclk);
258 	clk_put(fclk);
259 	clk_put(iclk);
260 	fclk = iclk = hclk = NULL;
261 }
262 
263 /*-------------------------------------------------------------------------*/
264 static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
265 {
266 	if (!valid_port(port))
267 		return;
268 
269 	if (!gpio_is_valid(pdata->vbus_pin[port]))
270 		return;
271 
272 	gpio_set_value(pdata->vbus_pin[port],
273 		       pdata->vbus_pin_active_low[port] ^ enable);
274 }
275 
276 static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
277 {
278 	if (!valid_port(port))
279 		return -EINVAL;
280 
281 	if (!gpio_is_valid(pdata->vbus_pin[port]))
282 		return -EINVAL;
283 
284 	return gpio_get_value(pdata->vbus_pin[port]) ^
285 		pdata->vbus_pin_active_low[port];
286 }
287 
288 /*
289  * Update the status data from the hub with the over-current indicator change.
290  */
291 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
292 {
293 	struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
294 	int length = orig_ohci_hub_status_data(hcd, buf);
295 	int port;
296 
297 	at91_for_each_port(port) {
298 		if (pdata->overcurrent_changed[port]) {
299 			if (!length)
300 				length = 1;
301 			buf[0] |= 1 << (port + 1);
302 		}
303 	}
304 
305 	return length;
306 }
307 
308 /*
309  * Look at the control requests to the root hub and see if we need to override.
310  */
311 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
312 				 u16 wIndex, char *buf, u16 wLength)
313 {
314 	struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
315 	struct usb_hub_descriptor *desc;
316 	int ret = -EINVAL;
317 	u32 *data = (u32 *)buf;
318 
319 	dev_dbg(hcd->self.controller,
320 		"ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
321 		hcd, typeReq, wValue, wIndex, buf, wLength);
322 
323 	wIndex--;
324 
325 	switch (typeReq) {
326 	case SetPortFeature:
327 		if (wValue == USB_PORT_FEAT_POWER) {
328 			dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
329 			if (valid_port(wIndex)) {
330 				ohci_at91_usb_set_power(pdata, wIndex, 1);
331 				ret = 0;
332 			}
333 
334 			goto out;
335 		}
336 		break;
337 
338 	case ClearPortFeature:
339 		switch (wValue) {
340 		case USB_PORT_FEAT_C_OVER_CURRENT:
341 			dev_dbg(hcd->self.controller,
342 				"ClearPortFeature: C_OVER_CURRENT\n");
343 
344 			if (valid_port(wIndex)) {
345 				pdata->overcurrent_changed[wIndex] = 0;
346 				pdata->overcurrent_status[wIndex] = 0;
347 			}
348 
349 			goto out;
350 
351 		case USB_PORT_FEAT_OVER_CURRENT:
352 			dev_dbg(hcd->self.controller,
353 				"ClearPortFeature: OVER_CURRENT\n");
354 
355 			if (valid_port(wIndex))
356 				pdata->overcurrent_status[wIndex] = 0;
357 
358 			goto out;
359 
360 		case USB_PORT_FEAT_POWER:
361 			dev_dbg(hcd->self.controller,
362 				"ClearPortFeature: POWER\n");
363 
364 			if (valid_port(wIndex)) {
365 				ohci_at91_usb_set_power(pdata, wIndex, 0);
366 				return 0;
367 			}
368 		}
369 		break;
370 	}
371 
372 	ret = orig_ohci_hub_control(hcd, typeReq, wValue, wIndex + 1,
373 				buf, wLength);
374 	if (ret)
375 		goto out;
376 
377 	switch (typeReq) {
378 	case GetHubDescriptor:
379 
380 		/* update the hub's descriptor */
381 
382 		desc = (struct usb_hub_descriptor *)buf;
383 
384 		dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
385 			desc->wHubCharacteristics);
386 
387 		/* remove the old configurations for power-switching, and
388 		 * over-current protection, and insert our new configuration
389 		 */
390 
391 		desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
392 		desc->wHubCharacteristics |= cpu_to_le16(0x0001);
393 
394 		if (pdata->overcurrent_supported) {
395 			desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
396 			desc->wHubCharacteristics |=  cpu_to_le16(0x0008|0x0001);
397 		}
398 
399 		dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
400 			desc->wHubCharacteristics);
401 
402 		return ret;
403 
404 	case GetPortStatus:
405 		/* check port status */
406 
407 		dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
408 
409 		if (valid_port(wIndex)) {
410 			if (!ohci_at91_usb_get_power(pdata, wIndex))
411 				*data &= ~cpu_to_le32(RH_PS_PPS);
412 
413 			if (pdata->overcurrent_changed[wIndex])
414 				*data |= cpu_to_le32(RH_PS_OCIC);
415 
416 			if (pdata->overcurrent_status[wIndex])
417 				*data |= cpu_to_le32(RH_PS_POCI);
418 		}
419 	}
420 
421  out:
422 	return ret;
423 }
424 
425 /*-------------------------------------------------------------------------*/
426 
427 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
428 {
429 	struct platform_device *pdev = data;
430 	struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
431 	int val, gpio, port;
432 
433 	/* From the GPIO notifying the over-current situation, find
434 	 * out the corresponding port */
435 	at91_for_each_port(port) {
436 		if (gpio_is_valid(pdata->overcurrent_pin[port]) &&
437 				gpio_to_irq(pdata->overcurrent_pin[port]) == irq) {
438 			gpio = pdata->overcurrent_pin[port];
439 			break;
440 		}
441 	}
442 
443 	if (port == AT91_MAX_USBH_PORTS) {
444 		dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
445 		return IRQ_HANDLED;
446 	}
447 
448 	val = gpio_get_value(gpio);
449 
450 	/* When notified of an over-current situation, disable power
451 	   on the corresponding port, and mark this port in
452 	   over-current. */
453 	if (!val) {
454 		ohci_at91_usb_set_power(pdata, port, 0);
455 		pdata->overcurrent_status[port]  = 1;
456 		pdata->overcurrent_changed[port] = 1;
457 	}
458 
459 	dev_dbg(& pdev->dev, "overcurrent situation %s\n",
460 		val ? "exited" : "notified");
461 
462 	return IRQ_HANDLED;
463 }
464 
465 #ifdef CONFIG_OF
466 static const struct of_device_id at91_ohci_dt_ids[] = {
467 	{ .compatible = "atmel,at91rm9200-ohci" },
468 	{ /* sentinel */ }
469 };
470 
471 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
472 
473 static int ohci_at91_of_init(struct platform_device *pdev)
474 {
475 	struct device_node *np = pdev->dev.of_node;
476 	int i, gpio, ret;
477 	enum of_gpio_flags flags;
478 	struct at91_usbh_data	*pdata;
479 	u32 ports;
480 
481 	if (!np)
482 		return 0;
483 
484 	/* Right now device-tree probed devices don't get dma_mask set.
485 	 * Since shared usb code relies on it, set it here for now.
486 	 * Once we have dma capability bindings this can go away.
487 	 */
488 	ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
489 	if (ret)
490 		return ret;
491 
492 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
493 	if (!pdata)
494 		return -ENOMEM;
495 
496 	if (!of_property_read_u32(np, "num-ports", &ports))
497 		pdata->ports = ports;
498 
499 	at91_for_each_port(i) {
500 		gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i, &flags);
501 		pdata->vbus_pin[i] = gpio;
502 		if (!gpio_is_valid(gpio))
503 			continue;
504 		pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
505 	}
506 
507 	at91_for_each_port(i)
508 		pdata->overcurrent_pin[i] =
509 			of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);
510 
511 	pdev->dev.platform_data = pdata;
512 
513 	return 0;
514 }
515 #else
516 static int ohci_at91_of_init(struct platform_device *pdev)
517 {
518 	return 0;
519 }
520 #endif
521 
522 /*-------------------------------------------------------------------------*/
523 
524 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
525 {
526 	struct at91_usbh_data	*pdata;
527 	int			i;
528 	int			gpio;
529 	int			ret;
530 
531 	ret = ohci_at91_of_init(pdev);
532 	if (ret)
533 		return ret;
534 
535 	pdata = dev_get_platdata(&pdev->dev);
536 
537 	if (pdata) {
538 		at91_for_each_port(i) {
539 			/*
540 			 * do not configure PIO if not in relation with
541 			 * real USB port on board
542 			 */
543 			if (i >= pdata->ports) {
544 				pdata->vbus_pin[i] = -EINVAL;
545 				pdata->overcurrent_pin[i] = -EINVAL;
546 				break;
547 			}
548 
549 			if (!gpio_is_valid(pdata->vbus_pin[i]))
550 				continue;
551 			gpio = pdata->vbus_pin[i];
552 
553 			ret = gpio_request(gpio, "ohci_vbus");
554 			if (ret) {
555 				dev_err(&pdev->dev,
556 					"can't request vbus gpio %d\n", gpio);
557 				continue;
558 			}
559 			ret = gpio_direction_output(gpio,
560 						!pdata->vbus_pin_active_low[i]);
561 			if (ret) {
562 				dev_err(&pdev->dev,
563 					"can't put vbus gpio %d as output %d\n",
564 					gpio, !pdata->vbus_pin_active_low[i]);
565 				gpio_free(gpio);
566 				continue;
567 			}
568 
569 			ohci_at91_usb_set_power(pdata, i, 1);
570 		}
571 
572 		at91_for_each_port(i) {
573 			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
574 				continue;
575 			gpio = pdata->overcurrent_pin[i];
576 
577 			ret = gpio_request(gpio, "ohci_overcurrent");
578 			if (ret) {
579 				dev_err(&pdev->dev,
580 					"can't request overcurrent gpio %d\n",
581 					gpio);
582 				continue;
583 			}
584 
585 			ret = gpio_direction_input(gpio);
586 			if (ret) {
587 				dev_err(&pdev->dev,
588 					"can't configure overcurrent gpio %d as input\n",
589 					gpio);
590 				gpio_free(gpio);
591 				continue;
592 			}
593 
594 			ret = request_irq(gpio_to_irq(gpio),
595 					  ohci_hcd_at91_overcurrent_irq,
596 					  IRQF_SHARED, "ohci_overcurrent", pdev);
597 			if (ret) {
598 				gpio_free(gpio);
599 				dev_err(&pdev->dev,
600 					"can't get gpio IRQ for overcurrent\n");
601 			}
602 		}
603 	}
604 
605 	device_init_wakeup(&pdev->dev, 1);
606 	return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
607 }
608 
609 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
610 {
611 	struct at91_usbh_data	*pdata = dev_get_platdata(&pdev->dev);
612 	int			i;
613 
614 	if (pdata) {
615 		at91_for_each_port(i) {
616 			if (!gpio_is_valid(pdata->vbus_pin[i]))
617 				continue;
618 			ohci_at91_usb_set_power(pdata, i, 0);
619 			gpio_free(pdata->vbus_pin[i]);
620 		}
621 
622 		at91_for_each_port(i) {
623 			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
624 				continue;
625 			free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
626 			gpio_free(pdata->overcurrent_pin[i]);
627 		}
628 	}
629 
630 	device_init_wakeup(&pdev->dev, 0);
631 	usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
632 	return 0;
633 }
634 
635 #ifdef CONFIG_PM
636 
637 static int
638 ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
639 {
640 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
641 	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
642 
643 	if (device_may_wakeup(&pdev->dev))
644 		enable_irq_wake(hcd->irq);
645 
646 	/*
647 	 * The integrated transceivers seem unable to notice disconnect,
648 	 * reconnect, or wakeup without the 48 MHz clock active.  so for
649 	 * correctness, always discard connection state (using reset).
650 	 *
651 	 * REVISIT: some boards will be able to turn VBUS off...
652 	 */
653 	if (at91_suspend_entering_slow_clock()) {
654 		ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
655 		ohci->hc_control &= OHCI_CTRL_RWC;
656 		ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
657 		ohci->rh_state = OHCI_RH_HALTED;
658 
659 		/* flush the writes */
660 		(void) ohci_readl (ohci, &ohci->regs->control);
661 		at91_stop_clock();
662 	}
663 
664 	return 0;
665 }
666 
667 static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
668 {
669 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
670 
671 	if (device_may_wakeup(&pdev->dev))
672 		disable_irq_wake(hcd->irq);
673 
674 	if (!clocked)
675 		at91_start_clock();
676 
677 	ohci_resume(hcd, false);
678 	return 0;
679 }
680 #else
681 #define ohci_hcd_at91_drv_suspend NULL
682 #define ohci_hcd_at91_drv_resume  NULL
683 #endif
684 
685 static struct platform_driver ohci_hcd_at91_driver = {
686 	.probe		= ohci_hcd_at91_drv_probe,
687 	.remove		= ohci_hcd_at91_drv_remove,
688 	.shutdown	= usb_hcd_platform_shutdown,
689 	.suspend	= ohci_hcd_at91_drv_suspend,
690 	.resume		= ohci_hcd_at91_drv_resume,
691 	.driver		= {
692 		.name	= "at91_ohci",
693 		.owner	= THIS_MODULE,
694 		.of_match_table	= of_match_ptr(at91_ohci_dt_ids),
695 	},
696 };
697 
698 static int __init ohci_at91_init(void)
699 {
700 	if (usb_disabled())
701 		return -ENODEV;
702 
703 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
704 	ohci_init_driver(&ohci_at91_hc_driver, NULL);
705 
706 	/*
707 	 * The Atmel HW has some unusual quirks, which require Atmel-specific
708 	 * workarounds. We override certain hc_driver functions here to
709 	 * achieve that. We explicitly do not enhance ohci_driver_overrides to
710 	 * allow this more easily, since this is an unusual case, and we don't
711 	 * want to encourage others to override these functions by making it
712 	 * too easy.
713 	 */
714 
715 	orig_ohci_hub_control = ohci_at91_hc_driver.hub_control;
716 	orig_ohci_hub_status_data = ohci_at91_hc_driver.hub_status_data;
717 
718 	ohci_at91_hc_driver.hub_status_data	= ohci_at91_hub_status_data;
719 	ohci_at91_hc_driver.hub_control		= ohci_at91_hub_control;
720 
721 	return platform_driver_register(&ohci_hcd_at91_driver);
722 }
723 module_init(ohci_at91_init);
724 
725 static void __exit ohci_at91_cleanup(void)
726 {
727 	platform_driver_unregister(&ohci_hcd_at91_driver);
728 }
729 module_exit(ohci_at91_cleanup);
730 
731 MODULE_DESCRIPTION(DRIVER_DESC);
732 MODULE_LICENSE("GPL");
733 MODULE_ALIAS("platform:at91_ohci");
734