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/platform_device.h>
17 #include <linux/of_platform.h>
18 #include <linux/of_gpio.h>
19 
20 #include <mach/hardware.h>
21 #include <asm/gpio.h>
22 
23 #include <mach/board.h>
24 #include <mach/cpu.h>
25 
26 #ifndef CONFIG_ARCH_AT91
27 #error "CONFIG_ARCH_AT91 must be defined."
28 #endif
29 
30 #define valid_port(index)	((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
31 #define at91_for_each_port(index)	\
32 		for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
33 
34 /* interface and function clocks; sometimes also an AHB clock */
35 static struct clk *iclk, *fclk, *hclk;
36 static int clocked;
37 
38 extern int usb_disabled(void);
39 
40 /*-------------------------------------------------------------------------*/
41 
at91_start_clock(void)42 static void at91_start_clock(void)
43 {
44 	clk_enable(hclk);
45 	clk_enable(iclk);
46 	clk_enable(fclk);
47 	clocked = 1;
48 }
49 
at91_stop_clock(void)50 static void at91_stop_clock(void)
51 {
52 	clk_disable(fclk);
53 	clk_disable(iclk);
54 	clk_disable(hclk);
55 	clocked = 0;
56 }
57 
at91_start_hc(struct platform_device * pdev)58 static void at91_start_hc(struct platform_device *pdev)
59 {
60 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
61 	struct ohci_regs __iomem *regs = hcd->regs;
62 
63 	dev_dbg(&pdev->dev, "start\n");
64 
65 	/*
66 	 * Start the USB clocks.
67 	 */
68 	at91_start_clock();
69 
70 	/*
71 	 * The USB host controller must remain in reset.
72 	 */
73 	writel(0, &regs->control);
74 }
75 
at91_stop_hc(struct platform_device * pdev)76 static void at91_stop_hc(struct platform_device *pdev)
77 {
78 	struct usb_hcd *hcd = platform_get_drvdata(pdev);
79 	struct ohci_regs __iomem *regs = hcd->regs;
80 
81 	dev_dbg(&pdev->dev, "stop\n");
82 
83 	/*
84 	 * Put the USB host controller into reset.
85 	 */
86 	writel(0, &regs->control);
87 
88 	/*
89 	 * Stop the USB clocks.
90 	 */
91 	at91_stop_clock();
92 }
93 
94 
95 /*-------------------------------------------------------------------------*/
96 
97 static void __devexit usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
98 
99 /* configure so an HC device and id are always provided */
100 /* always called with process context; sleeping is OK */
101 
102 
103 /**
104  * usb_hcd_at91_probe - initialize AT91-based HCDs
105  * Context: !in_interrupt()
106  *
107  * Allocates basic resources for this USB host controller, and
108  * then invokes the start() method for the HCD associated with it
109  * through the hotplug entry's driver_data.
110  */
usb_hcd_at91_probe(const struct hc_driver * driver,struct platform_device * pdev)111 static int __devinit usb_hcd_at91_probe(const struct hc_driver *driver,
112 			struct platform_device *pdev)
113 {
114 	int retval;
115 	struct usb_hcd *hcd = NULL;
116 
117 	if (pdev->num_resources != 2) {
118 		pr_debug("hcd probe: invalid num_resources");
119 		return -ENODEV;
120 	}
121 
122 	if ((pdev->resource[0].flags != IORESOURCE_MEM)
123 			|| (pdev->resource[1].flags != IORESOURCE_IRQ)) {
124 		pr_debug("hcd probe: invalid resource type\n");
125 		return -ENODEV;
126 	}
127 
128 	hcd = usb_create_hcd(driver, &pdev->dev, "at91");
129 	if (!hcd)
130 		return -ENOMEM;
131 	hcd->rsrc_start = pdev->resource[0].start;
132 	hcd->rsrc_len = pdev->resource[0].end - pdev->resource[0].start + 1;
133 
134 	if (!request_mem_region(hcd->rsrc_start, hcd->rsrc_len, hcd_name)) {
135 		pr_debug("request_mem_region failed\n");
136 		retval = -EBUSY;
137 		goto err1;
138 	}
139 
140 	hcd->regs = ioremap(hcd->rsrc_start, hcd->rsrc_len);
141 	if (!hcd->regs) {
142 		pr_debug("ioremap failed\n");
143 		retval = -EIO;
144 		goto err2;
145 	}
146 
147 	iclk = clk_get(&pdev->dev, "ohci_clk");
148 	if (IS_ERR(iclk)) {
149 		dev_err(&pdev->dev, "failed to get ohci_clk\n");
150 		retval = PTR_ERR(iclk);
151 		goto err3;
152 	}
153 	fclk = clk_get(&pdev->dev, "uhpck");
154 	if (IS_ERR(fclk)) {
155 		dev_err(&pdev->dev, "failed to get uhpck\n");
156 		retval = PTR_ERR(fclk);
157 		goto err4;
158 	}
159 	hclk = clk_get(&pdev->dev, "hclk");
160 	if (IS_ERR(hclk)) {
161 		dev_err(&pdev->dev, "failed to get hclk\n");
162 		retval = PTR_ERR(hclk);
163 		goto err5;
164 	}
165 
166 	at91_start_hc(pdev);
167 	ohci_hcd_init(hcd_to_ohci(hcd));
168 
169 	retval = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_SHARED);
170 	if (retval == 0)
171 		return retval;
172 
173 	/* Error handling */
174 	at91_stop_hc(pdev);
175 
176 	clk_put(hclk);
177  err5:
178 	clk_put(fclk);
179  err4:
180 	clk_put(iclk);
181 
182  err3:
183 	iounmap(hcd->regs);
184 
185  err2:
186 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
187 
188  err1:
189 	usb_put_hcd(hcd);
190 	return retval;
191 }
192 
193 
194 /* may be called with controller, bus, and devices active */
195 
196 /**
197  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
198  * @dev: USB Host Controller being removed
199  * Context: !in_interrupt()
200  *
201  * Reverses the effect of usb_hcd_at91_probe(), first invoking
202  * the HCD's stop() method.  It is always called from a thread
203  * context, "rmmod" or something similar.
204  *
205  */
usb_hcd_at91_remove(struct usb_hcd * hcd,struct platform_device * pdev)206 static void __devexit usb_hcd_at91_remove(struct usb_hcd *hcd,
207 				struct platform_device *pdev)
208 {
209 	usb_remove_hcd(hcd);
210 	at91_stop_hc(pdev);
211 	iounmap(hcd->regs);
212 	release_mem_region(hcd->rsrc_start, hcd->rsrc_len);
213 	usb_put_hcd(hcd);
214 
215 	clk_put(hclk);
216 	clk_put(fclk);
217 	clk_put(iclk);
218 	fclk = iclk = hclk = NULL;
219 
220 	dev_set_drvdata(&pdev->dev, NULL);
221 }
222 
223 /*-------------------------------------------------------------------------*/
224 
225 static int __devinit
ohci_at91_reset(struct usb_hcd * hcd)226 ohci_at91_reset (struct usb_hcd *hcd)
227 {
228 	struct at91_usbh_data	*board = hcd->self.controller->platform_data;
229 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
230 	int			ret;
231 
232 	if ((ret = ohci_init(ohci)) < 0)
233 		return ret;
234 
235 	ohci->num_ports = board->ports;
236 	return 0;
237 }
238 
239 static int __devinit
ohci_at91_start(struct usb_hcd * hcd)240 ohci_at91_start (struct usb_hcd *hcd)
241 {
242 	struct ohci_hcd		*ohci = hcd_to_ohci (hcd);
243 	int			ret;
244 
245 	if ((ret = ohci_run(ohci)) < 0) {
246 		err("can't start %s", hcd->self.bus_name);
247 		ohci_stop(hcd);
248 		return ret;
249 	}
250 	return 0;
251 }
252 
ohci_at91_usb_set_power(struct at91_usbh_data * pdata,int port,int enable)253 static void ohci_at91_usb_set_power(struct at91_usbh_data *pdata, int port, int enable)
254 {
255 	if (!valid_port(port))
256 		return;
257 
258 	if (!gpio_is_valid(pdata->vbus_pin[port]))
259 		return;
260 
261 	gpio_set_value(pdata->vbus_pin[port],
262 		       pdata->vbus_pin_active_low[port] ^ enable);
263 }
264 
ohci_at91_usb_get_power(struct at91_usbh_data * pdata,int port)265 static int ohci_at91_usb_get_power(struct at91_usbh_data *pdata, int port)
266 {
267 	if (!valid_port(port))
268 		return -EINVAL;
269 
270 	if (!gpio_is_valid(pdata->vbus_pin[port]))
271 		return -EINVAL;
272 
273 	return gpio_get_value(pdata->vbus_pin[port]) ^
274 		pdata->vbus_pin_active_low[port];
275 }
276 
277 /*
278  * Update the status data from the hub with the over-current indicator change.
279  */
ohci_at91_hub_status_data(struct usb_hcd * hcd,char * buf)280 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
281 {
282 	struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
283 	int length = ohci_hub_status_data(hcd, buf);
284 	int port;
285 
286 	at91_for_each_port(port) {
287 		if (pdata->overcurrent_changed[port]) {
288 			if (!length)
289 				length = 1;
290 			buf[0] |= 1 << (port + 1);
291 		}
292 	}
293 
294 	return length;
295 }
296 
297 /*
298  * Look at the control requests to the root hub and see if we need to override.
299  */
ohci_at91_hub_control(struct usb_hcd * hcd,u16 typeReq,u16 wValue,u16 wIndex,char * buf,u16 wLength)300 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
301 				 u16 wIndex, char *buf, u16 wLength)
302 {
303 	struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
304 	struct usb_hub_descriptor *desc;
305 	int ret = -EINVAL;
306 	u32 *data = (u32 *)buf;
307 
308 	dev_dbg(hcd->self.controller,
309 		"ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
310 		hcd, typeReq, wValue, wIndex, buf, wLength);
311 
312 	wIndex--;
313 
314 	switch (typeReq) {
315 	case SetPortFeature:
316 		if (wValue == USB_PORT_FEAT_POWER) {
317 			dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
318 			if (valid_port(wIndex)) {
319 				ohci_at91_usb_set_power(pdata, wIndex, 1);
320 				ret = 0;
321 			}
322 
323 			goto out;
324 		}
325 		break;
326 
327 	case ClearPortFeature:
328 		switch (wValue) {
329 		case USB_PORT_FEAT_C_OVER_CURRENT:
330 			dev_dbg(hcd->self.controller,
331 				"ClearPortFeature: C_OVER_CURRENT\n");
332 
333 			if (valid_port(wIndex)) {
334 				pdata->overcurrent_changed[wIndex] = 0;
335 				pdata->overcurrent_status[wIndex] = 0;
336 			}
337 
338 			goto out;
339 
340 		case USB_PORT_FEAT_OVER_CURRENT:
341 			dev_dbg(hcd->self.controller,
342 				"ClearPortFeature: OVER_CURRENT\n");
343 
344 			if (valid_port(wIndex))
345 				pdata->overcurrent_status[wIndex] = 0;
346 
347 			goto out;
348 
349 		case USB_PORT_FEAT_POWER:
350 			dev_dbg(hcd->self.controller,
351 				"ClearPortFeature: POWER\n");
352 
353 			if (valid_port(wIndex)) {
354 				ohci_at91_usb_set_power(pdata, wIndex, 0);
355 				return 0;
356 			}
357 		}
358 		break;
359 	}
360 
361 	ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
362 	if (ret)
363 		goto out;
364 
365 	switch (typeReq) {
366 	case GetHubDescriptor:
367 
368 		/* update the hub's descriptor */
369 
370 		desc = (struct usb_hub_descriptor *)buf;
371 
372 		dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
373 			desc->wHubCharacteristics);
374 
375 		/* remove the old configurations for power-switching, and
376 		 * over-current protection, and insert our new configuration
377 		 */
378 
379 		desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
380 		desc->wHubCharacteristics |= cpu_to_le16(0x0001);
381 
382 		if (pdata->overcurrent_supported) {
383 			desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
384 			desc->wHubCharacteristics |=  cpu_to_le16(0x0008|0x0001);
385 		}
386 
387 		dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
388 			desc->wHubCharacteristics);
389 
390 		return ret;
391 
392 	case GetPortStatus:
393 		/* check port status */
394 
395 		dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
396 
397 		if (valid_port(wIndex)) {
398 			if (!ohci_at91_usb_get_power(pdata, wIndex))
399 				*data &= ~cpu_to_le32(RH_PS_PPS);
400 
401 			if (pdata->overcurrent_changed[wIndex])
402 				*data |= cpu_to_le32(RH_PS_OCIC);
403 
404 			if (pdata->overcurrent_status[wIndex])
405 				*data |= cpu_to_le32(RH_PS_POCI);
406 		}
407 	}
408 
409  out:
410 	return ret;
411 }
412 
413 /*-------------------------------------------------------------------------*/
414 
415 static const struct hc_driver ohci_at91_hc_driver = {
416 	.description =		hcd_name,
417 	.product_desc =		"AT91 OHCI",
418 	.hcd_priv_size =	sizeof(struct ohci_hcd),
419 
420 	/*
421 	 * generic hardware linkage
422 	 */
423 	.irq =			ohci_irq,
424 	.flags =		HCD_USB11 | HCD_MEMORY,
425 
426 	/*
427 	 * basic lifecycle operations
428 	 */
429 	.reset =		ohci_at91_reset,
430 	.start =		ohci_at91_start,
431 	.stop =			ohci_stop,
432 	.shutdown =		ohci_shutdown,
433 
434 	/*
435 	 * managing i/o requests and associated device resources
436 	 */
437 	.urb_enqueue =		ohci_urb_enqueue,
438 	.urb_dequeue =		ohci_urb_dequeue,
439 	.endpoint_disable =	ohci_endpoint_disable,
440 
441 	/*
442 	 * scheduling support
443 	 */
444 	.get_frame_number =	ohci_get_frame,
445 
446 	/*
447 	 * root hub support
448 	 */
449 	.hub_status_data =	ohci_at91_hub_status_data,
450 	.hub_control =		ohci_at91_hub_control,
451 #ifdef CONFIG_PM
452 	.bus_suspend =		ohci_bus_suspend,
453 	.bus_resume =		ohci_bus_resume,
454 #endif
455 	.start_port_reset =	ohci_start_port_reset,
456 };
457 
458 /*-------------------------------------------------------------------------*/
459 
ohci_hcd_at91_overcurrent_irq(int irq,void * data)460 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
461 {
462 	struct platform_device *pdev = data;
463 	struct at91_usbh_data *pdata = pdev->dev.platform_data;
464 	int val, gpio, port;
465 
466 	/* From the GPIO notifying the over-current situation, find
467 	 * out the corresponding port */
468 	at91_for_each_port(port) {
469 		if (gpio_is_valid(pdata->overcurrent_pin[port]) &&
470 				gpio_to_irq(pdata->overcurrent_pin[port]) == irq) {
471 			gpio = pdata->overcurrent_pin[port];
472 			break;
473 		}
474 	}
475 
476 	if (port == AT91_MAX_USBH_PORTS) {
477 		dev_err(& pdev->dev, "overcurrent interrupt from unknown GPIO\n");
478 		return IRQ_HANDLED;
479 	}
480 
481 	val = gpio_get_value(gpio);
482 
483 	/* When notified of an over-current situation, disable power
484 	   on the corresponding port, and mark this port in
485 	   over-current. */
486 	if (!val) {
487 		ohci_at91_usb_set_power(pdata, port, 0);
488 		pdata->overcurrent_status[port]  = 1;
489 		pdata->overcurrent_changed[port] = 1;
490 	}
491 
492 	dev_dbg(& pdev->dev, "overcurrent situation %s\n",
493 		val ? "exited" : "notified");
494 
495 	return IRQ_HANDLED;
496 }
497 
498 #ifdef CONFIG_OF
499 static const struct of_device_id at91_ohci_dt_ids[] = {
500 	{ .compatible = "atmel,at91rm9200-ohci" },
501 	{ /* sentinel */ }
502 };
503 
504 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
505 
506 static u64 at91_ohci_dma_mask = DMA_BIT_MASK(32);
507 
ohci_at91_of_init(struct platform_device * pdev)508 static int __devinit ohci_at91_of_init(struct platform_device *pdev)
509 {
510 	struct device_node *np = pdev->dev.of_node;
511 	int i, gpio;
512 	enum of_gpio_flags flags;
513 	struct at91_usbh_data	*pdata;
514 	u32 ports;
515 
516 	if (!np)
517 		return 0;
518 
519 	/* Right now device-tree probed devices don't get dma_mask set.
520 	 * Since shared usb code relies on it, set it here for now.
521 	 * Once we have dma capability bindings this can go away.
522 	 */
523 	if (!pdev->dev.dma_mask)
524 		pdev->dev.dma_mask = &at91_ohci_dma_mask;
525 
526 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
527 	if (!pdata)
528 		return -ENOMEM;
529 
530 	if (!of_property_read_u32(np, "num-ports", &ports))
531 		pdata->ports = ports;
532 
533 	at91_for_each_port(i) {
534 		gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i, &flags);
535 		pdata->vbus_pin[i] = gpio;
536 		if (!gpio_is_valid(gpio))
537 			continue;
538 		pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
539 	}
540 
541 	at91_for_each_port(i)
542 		pdata->overcurrent_pin[i] =
543 			of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);
544 
545 	pdev->dev.platform_data = pdata;
546 
547 	return 0;
548 }
549 #else
ohci_at91_of_init(struct platform_device * pdev)550 static int __devinit ohci_at91_of_init(struct platform_device *pdev)
551 {
552 	return 0;
553 }
554 #endif
555 
556 /*-------------------------------------------------------------------------*/
557 
ohci_hcd_at91_drv_probe(struct platform_device * pdev)558 static int __devinit ohci_hcd_at91_drv_probe(struct platform_device *pdev)
559 {
560 	struct at91_usbh_data	*pdata;
561 	int			i;
562 	int			gpio;
563 	int			ret;
564 
565 	ret = ohci_at91_of_init(pdev);
566 	if (ret)
567 		return ret;
568 
569 	pdata = pdev->dev.platform_data;
570 
571 	if (pdata) {
572 		at91_for_each_port(i) {
573 			/*
574 			 * do not configure PIO if not in relation with
575 			 * real USB port on board
576 			 */
577 			if (i >= pdata->ports) {
578 				pdata->vbus_pin[i] = -EINVAL;
579 				pdata->overcurrent_pin[i] = -EINVAL;
580 				break;
581 			}
582 
583 			if (!gpio_is_valid(pdata->vbus_pin[i]))
584 				continue;
585 			gpio = pdata->vbus_pin[i];
586 
587 			ret = gpio_request(gpio, "ohci_vbus");
588 			if (ret) {
589 				dev_err(&pdev->dev,
590 					"can't request vbus gpio %d\n", gpio);
591 				continue;
592 			}
593 			ret = gpio_direction_output(gpio,
594 						!pdata->vbus_pin_active_low[i]);
595 			if (ret) {
596 				dev_err(&pdev->dev,
597 					"can't put vbus gpio %d as output %d\n",
598 					gpio, !pdata->vbus_pin_active_low[i]);
599 				gpio_free(gpio);
600 				continue;
601 			}
602 
603 			ohci_at91_usb_set_power(pdata, i, 1);
604 		}
605 
606 		at91_for_each_port(i) {
607 			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
608 				continue;
609 			gpio = pdata->overcurrent_pin[i];
610 
611 			ret = gpio_request(gpio, "ohci_overcurrent");
612 			if (ret) {
613 				dev_err(&pdev->dev,
614 					"can't request overcurrent gpio %d\n",
615 					gpio);
616 				continue;
617 			}
618 
619 			ret = gpio_direction_input(gpio);
620 			if (ret) {
621 				dev_err(&pdev->dev,
622 					"can't configure overcurrent gpio %d as input\n",
623 					gpio);
624 				gpio_free(gpio);
625 				continue;
626 			}
627 
628 			ret = request_irq(gpio_to_irq(gpio),
629 					  ohci_hcd_at91_overcurrent_irq,
630 					  IRQF_SHARED, "ohci_overcurrent", pdev);
631 			if (ret) {
632 				gpio_free(gpio);
633 				dev_err(&pdev->dev,
634 					"can't get gpio IRQ for overcurrent\n");
635 			}
636 		}
637 	}
638 
639 	device_init_wakeup(&pdev->dev, 1);
640 	return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
641 }
642 
ohci_hcd_at91_drv_remove(struct platform_device * pdev)643 static int __devexit ohci_hcd_at91_drv_remove(struct platform_device *pdev)
644 {
645 	struct at91_usbh_data	*pdata = pdev->dev.platform_data;
646 	int			i;
647 
648 	if (pdata) {
649 		at91_for_each_port(i) {
650 			if (!gpio_is_valid(pdata->vbus_pin[i]))
651 				continue;
652 			ohci_at91_usb_set_power(pdata, i, 0);
653 			gpio_free(pdata->vbus_pin[i]);
654 		}
655 
656 		at91_for_each_port(i) {
657 			if (!gpio_is_valid(pdata->overcurrent_pin[i]))
658 				continue;
659 			free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
660 			gpio_free(pdata->overcurrent_pin[i]);
661 		}
662 	}
663 
664 	device_init_wakeup(&pdev->dev, 0);
665 	usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
666 	return 0;
667 }
668 
669 #ifdef CONFIG_PM
670 
671 static int
ohci_hcd_at91_drv_suspend(struct platform_device * pdev,pm_message_t mesg)672 ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
673 {
674 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
675 	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
676 
677 	if (device_may_wakeup(&pdev->dev))
678 		enable_irq_wake(hcd->irq);
679 
680 	/*
681 	 * The integrated transceivers seem unable to notice disconnect,
682 	 * reconnect, or wakeup without the 48 MHz clock active.  so for
683 	 * correctness, always discard connection state (using reset).
684 	 *
685 	 * REVISIT: some boards will be able to turn VBUS off...
686 	 */
687 	if (at91_suspend_entering_slow_clock()) {
688 		ohci_usb_reset (ohci);
689 		/* flush the writes */
690 		(void) ohci_readl (ohci, &ohci->regs->control);
691 		at91_stop_clock();
692 	}
693 
694 	return 0;
695 }
696 
ohci_hcd_at91_drv_resume(struct platform_device * pdev)697 static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
698 {
699 	struct usb_hcd	*hcd = platform_get_drvdata(pdev);
700 
701 	if (device_may_wakeup(&pdev->dev))
702 		disable_irq_wake(hcd->irq);
703 
704 	if (!clocked)
705 		at91_start_clock();
706 
707 	ohci_finish_controller_resume(hcd);
708 	return 0;
709 }
710 #else
711 #define ohci_hcd_at91_drv_suspend NULL
712 #define ohci_hcd_at91_drv_resume  NULL
713 #endif
714 
715 MODULE_ALIAS("platform:at91_ohci");
716 
717 static struct platform_driver ohci_hcd_at91_driver = {
718 	.probe		= ohci_hcd_at91_drv_probe,
719 	.remove		= __devexit_p(ohci_hcd_at91_drv_remove),
720 	.shutdown	= usb_hcd_platform_shutdown,
721 	.suspend	= ohci_hcd_at91_drv_suspend,
722 	.resume		= ohci_hcd_at91_drv_resume,
723 	.driver		= {
724 		.name	= "at91_ohci",
725 		.owner	= THIS_MODULE,
726 		.of_match_table	= of_match_ptr(at91_ohci_dt_ids),
727 	},
728 };
729