xref: /openbmc/linux/drivers/usb/host/ohci-at91.c (revision cce8e04c)
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/clk.h>
17 #include <linux/dma-mapping.h>
18 #include <linux/gpio/consumer.h>
19 #include <linux/of_platform.h>
20 #include <linux/platform_device.h>
21 #include <linux/platform_data/atmel.h>
22 #include <linux/io.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/mfd/syscon.h>
26 #include <linux/regmap.h>
27 #include <linux/usb.h>
28 #include <linux/usb/hcd.h>
29 #include <soc/at91/atmel-sfr.h>
30 
31 #include "ohci.h"
32 
33 #define valid_port(index)	((index) >= 0 && (index) < AT91_MAX_USBH_PORTS)
34 #define at91_for_each_port(index)	\
35 		for ((index) = 0; (index) < AT91_MAX_USBH_PORTS; (index)++)
36 
37 /* interface, function and usb clocks; sometimes also an AHB clock */
38 #define hcd_to_ohci_at91_priv(h) \
39 	((struct ohci_at91_priv *)hcd_to_ohci(h)->priv)
40 
41 #define AT91_MAX_USBH_PORTS	3
42 struct at91_usbh_data {
43 	struct gpio_desc *vbus_pin[AT91_MAX_USBH_PORTS];
44 	struct gpio_desc *overcurrent_pin[AT91_MAX_USBH_PORTS];
45 	u8 ports;				/* number of ports on root hub */
46 	u8 overcurrent_supported;
47 	u8 overcurrent_status[AT91_MAX_USBH_PORTS];
48 	u8 overcurrent_changed[AT91_MAX_USBH_PORTS];
49 };
50 
51 struct ohci_at91_priv {
52 	struct clk *iclk;
53 	struct clk *fclk;
54 	struct clk *hclk;
55 	bool clocked;
56 	bool wakeup;		/* Saved wake-up state for resume */
57 	struct regmap *sfr_regmap;
58 };
59 /* interface and function clocks; sometimes also an AHB clock */
60 
61 #define DRIVER_DESC "OHCI Atmel driver"
62 
63 static const char hcd_name[] = "ohci-atmel";
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_regs __iomem *regs = hcd->regs;
119 	struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
120 
121 	dev_dbg(&pdev->dev, "stop\n");
122 
123 	/*
124 	 * Put the USB host controller into reset.
125 	 */
126 	writel(0, &regs->control);
127 
128 	/*
129 	 * Stop the USB clocks.
130 	 */
131 	at91_stop_clock(ohci_at91);
132 }
133 
134 
135 /*-------------------------------------------------------------------------*/
136 
137 static void usb_hcd_at91_remove (struct usb_hcd *, struct platform_device *);
138 
139 static struct regmap *at91_dt_syscon_sfr(void)
140 {
141 	struct regmap *regmap;
142 
143 	regmap = syscon_regmap_lookup_by_compatible("atmel,sama5d2-sfr");
144 	if (IS_ERR(regmap))
145 		regmap = NULL;
146 
147 	return regmap;
148 }
149 
150 /* configure so an HC device and id are always provided */
151 /* always called with process context; sleeping is OK */
152 
153 
154 /**
155  * usb_hcd_at91_probe - initialize AT91-based HCDs
156  * Context: !in_interrupt()
157  *
158  * Allocates basic resources for this USB host controller, and
159  * then invokes the start() method for the HCD associated with it
160  * through the hotplug entry's driver_data.
161  */
162 static int usb_hcd_at91_probe(const struct hc_driver *driver,
163 			struct platform_device *pdev)
164 {
165 	struct at91_usbh_data *board;
166 	struct ohci_hcd *ohci;
167 	int retval;
168 	struct usb_hcd *hcd;
169 	struct ohci_at91_priv *ohci_at91;
170 	struct device *dev = &pdev->dev;
171 	struct resource *res;
172 	int irq;
173 
174 	irq = platform_get_irq(pdev, 0);
175 	if (irq < 0) {
176 		dev_dbg(dev, "hcd probe: missing irq resource\n");
177 		return irq;
178 	}
179 
180 	hcd = usb_create_hcd(driver, dev, "at91");
181 	if (!hcd)
182 		return -ENOMEM;
183 	ohci_at91 = hcd_to_ohci_at91_priv(hcd);
184 
185 	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
186 	hcd->regs = devm_ioremap_resource(dev, res);
187 	if (IS_ERR(hcd->regs)) {
188 		retval = PTR_ERR(hcd->regs);
189 		goto err;
190 	}
191 	hcd->rsrc_start = res->start;
192 	hcd->rsrc_len = resource_size(res);
193 
194 	ohci_at91->iclk = devm_clk_get(dev, "ohci_clk");
195 	if (IS_ERR(ohci_at91->iclk)) {
196 		dev_err(dev, "failed to get ohci_clk\n");
197 		retval = PTR_ERR(ohci_at91->iclk);
198 		goto err;
199 	}
200 	ohci_at91->fclk = devm_clk_get(dev, "uhpck");
201 	if (IS_ERR(ohci_at91->fclk)) {
202 		dev_err(dev, "failed to get uhpck\n");
203 		retval = PTR_ERR(ohci_at91->fclk);
204 		goto err;
205 	}
206 	ohci_at91->hclk = devm_clk_get(dev, "hclk");
207 	if (IS_ERR(ohci_at91->hclk)) {
208 		dev_err(dev, "failed to get hclk\n");
209 		retval = PTR_ERR(ohci_at91->hclk);
210 		goto err;
211 	}
212 
213 	ohci_at91->sfr_regmap = at91_dt_syscon_sfr();
214 	if (!ohci_at91->sfr_regmap)
215 		dev_dbg(dev, "failed to find sfr node\n");
216 
217 	board = hcd->self.controller->platform_data;
218 	ohci = hcd_to_ohci(hcd);
219 	ohci->num_ports = board->ports;
220 	at91_start_hc(pdev);
221 
222 	/*
223 	 * The RemoteWakeupConnected bit has to be set explicitly
224 	 * before calling ohci_run. The reset value of this bit is 0.
225 	 */
226 	ohci->hc_control = OHCI_CTRL_RWC;
227 
228 	retval = usb_add_hcd(hcd, irq, IRQF_SHARED);
229 	if (retval == 0) {
230 		device_wakeup_enable(hcd->self.controller);
231 		return retval;
232 	}
233 
234 	/* Error handling */
235 	at91_stop_hc(pdev);
236 
237  err:
238 	usb_put_hcd(hcd);
239 	return retval;
240 }
241 
242 
243 /* may be called with controller, bus, and devices active */
244 
245 /**
246  * usb_hcd_at91_remove - shutdown processing for AT91-based HCDs
247  * @dev: USB Host Controller being removed
248  * Context: !in_interrupt()
249  *
250  * Reverses the effect of usb_hcd_at91_probe(), first invoking
251  * the HCD's stop() method.  It is always called from a thread
252  * context, "rmmod" or something similar.
253  *
254  */
255 static void usb_hcd_at91_remove(struct usb_hcd *hcd,
256 				struct platform_device *pdev)
257 {
258 	usb_remove_hcd(hcd);
259 	at91_stop_hc(pdev);
260 	usb_put_hcd(hcd);
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 	gpiod_set_value(pdata->vbus_pin[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 	return gpiod_get_value(pdata->vbus_pin[port]);
278 }
279 
280 /*
281  * Update the status data from the hub with the over-current indicator change.
282  */
283 static int ohci_at91_hub_status_data(struct usb_hcd *hcd, char *buf)
284 {
285 	struct at91_usbh_data *pdata = hcd->self.controller->platform_data;
286 	int length = ohci_hub_status_data(hcd, buf);
287 	int port;
288 
289 	at91_for_each_port(port) {
290 		if (pdata->overcurrent_changed[port]) {
291 			if (!length)
292 				length = 1;
293 			buf[0] |= 1 << (port + 1);
294 		}
295 	}
296 
297 	return length;
298 }
299 
300 static int ohci_at91_port_suspend(struct regmap *regmap, u8 set)
301 {
302 	u32 regval;
303 	int ret;
304 
305 	if (!regmap)
306 		return 0;
307 
308 	ret = regmap_read(regmap, AT91_SFR_OHCIICR, &regval);
309 	if (ret)
310 		return ret;
311 
312 	if (set)
313 		regval |= AT91_OHCIICR_USB_SUSPEND;
314 	else
315 		regval &= ~AT91_OHCIICR_USB_SUSPEND;
316 
317 	regmap_write(regmap, AT91_SFR_OHCIICR, regval);
318 
319 	return 0;
320 }
321 
322 /*
323  * Look at the control requests to the root hub and see if we need to override.
324  */
325 static int ohci_at91_hub_control(struct usb_hcd *hcd, u16 typeReq, u16 wValue,
326 				 u16 wIndex, char *buf, u16 wLength)
327 {
328 	struct at91_usbh_data *pdata = dev_get_platdata(hcd->self.controller);
329 	struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
330 	struct usb_hub_descriptor *desc;
331 	int ret = -EINVAL;
332 	u32 *data = (u32 *)buf;
333 
334 	dev_dbg(hcd->self.controller,
335 		"ohci_at91_hub_control(%p,0x%04x,0x%04x,0x%04x,%p,%04x)\n",
336 		hcd, typeReq, wValue, wIndex, buf, wLength);
337 
338 	wIndex--;
339 
340 	switch (typeReq) {
341 	case SetPortFeature:
342 		switch (wValue) {
343 		case USB_PORT_FEAT_POWER:
344 			dev_dbg(hcd->self.controller, "SetPortFeat: POWER\n");
345 			if (valid_port(wIndex)) {
346 				ohci_at91_usb_set_power(pdata, wIndex, 1);
347 				ret = 0;
348 			}
349 
350 			goto out;
351 
352 		case USB_PORT_FEAT_SUSPEND:
353 			dev_dbg(hcd->self.controller, "SetPortFeat: SUSPEND\n");
354 			if (valid_port(wIndex) && ohci_at91->sfr_regmap) {
355 				ohci_at91_port_suspend(ohci_at91->sfr_regmap,
356 						       1);
357 				return 0;
358 			}
359 			break;
360 		}
361 		break;
362 
363 	case ClearPortFeature:
364 		switch (wValue) {
365 		case USB_PORT_FEAT_C_OVER_CURRENT:
366 			dev_dbg(hcd->self.controller,
367 				"ClearPortFeature: C_OVER_CURRENT\n");
368 
369 			if (valid_port(wIndex)) {
370 				pdata->overcurrent_changed[wIndex] = 0;
371 				pdata->overcurrent_status[wIndex] = 0;
372 			}
373 
374 			goto out;
375 
376 		case USB_PORT_FEAT_OVER_CURRENT:
377 			dev_dbg(hcd->self.controller,
378 				"ClearPortFeature: OVER_CURRENT\n");
379 
380 			if (valid_port(wIndex))
381 				pdata->overcurrent_status[wIndex] = 0;
382 
383 			goto out;
384 
385 		case USB_PORT_FEAT_POWER:
386 			dev_dbg(hcd->self.controller,
387 				"ClearPortFeature: POWER\n");
388 
389 			if (valid_port(wIndex)) {
390 				ohci_at91_usb_set_power(pdata, wIndex, 0);
391 				return 0;
392 			}
393 			break;
394 
395 		case USB_PORT_FEAT_SUSPEND:
396 			dev_dbg(hcd->self.controller, "ClearPortFeature: SUSPEND\n");
397 			if (valid_port(wIndex) && ohci_at91->sfr_regmap) {
398 				ohci_at91_port_suspend(ohci_at91->sfr_regmap,
399 						       0);
400 				return 0;
401 			}
402 			break;
403 		}
404 		break;
405 	}
406 
407 	ret = ohci_hub_control(hcd, typeReq, wValue, wIndex + 1, buf, wLength);
408 	if (ret)
409 		goto out;
410 
411 	switch (typeReq) {
412 	case GetHubDescriptor:
413 
414 		/* update the hub's descriptor */
415 
416 		desc = (struct usb_hub_descriptor *)buf;
417 
418 		dev_dbg(hcd->self.controller, "wHubCharacteristics 0x%04x\n",
419 			desc->wHubCharacteristics);
420 
421 		/* remove the old configurations for power-switching, and
422 		 * over-current protection, and insert our new configuration
423 		 */
424 
425 		desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_LPSM);
426 		desc->wHubCharacteristics |=
427 			cpu_to_le16(HUB_CHAR_INDV_PORT_LPSM);
428 
429 		if (pdata->overcurrent_supported) {
430 			desc->wHubCharacteristics &= ~cpu_to_le16(HUB_CHAR_OCPM);
431 			desc->wHubCharacteristics |=
432 				cpu_to_le16(HUB_CHAR_INDV_PORT_OCPM);
433 		}
434 
435 		dev_dbg(hcd->self.controller, "wHubCharacteristics after 0x%04x\n",
436 			desc->wHubCharacteristics);
437 
438 		return ret;
439 
440 	case GetPortStatus:
441 		/* check port status */
442 
443 		dev_dbg(hcd->self.controller, "GetPortStatus(%d)\n", wIndex);
444 
445 		if (valid_port(wIndex)) {
446 			if (!ohci_at91_usb_get_power(pdata, wIndex))
447 				*data &= ~cpu_to_le32(RH_PS_PPS);
448 
449 			if (pdata->overcurrent_changed[wIndex])
450 				*data |= cpu_to_le32(RH_PS_OCIC);
451 
452 			if (pdata->overcurrent_status[wIndex])
453 				*data |= cpu_to_le32(RH_PS_POCI);
454 		}
455 	}
456 
457  out:
458 	return ret;
459 }
460 
461 /*-------------------------------------------------------------------------*/
462 
463 static irqreturn_t ohci_hcd_at91_overcurrent_irq(int irq, void *data)
464 {
465 	struct platform_device *pdev = data;
466 	struct at91_usbh_data *pdata = dev_get_platdata(&pdev->dev);
467 	int val, port;
468 
469 	/* From the GPIO notifying the over-current situation, find
470 	 * out the corresponding port */
471 	at91_for_each_port(port) {
472 		if (gpiod_to_irq(pdata->overcurrent_pin[port]) == irq)
473 			break;
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 = gpiod_get_value(pdata->overcurrent_pin[port]);
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 static const struct of_device_id at91_ohci_dt_ids[] = {
499 	{ .compatible = "atmel,at91rm9200-ohci" },
500 	{ /* sentinel */ }
501 };
502 
503 MODULE_DEVICE_TABLE(of, at91_ohci_dt_ids);
504 
505 /*-------------------------------------------------------------------------*/
506 
507 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
508 {
509 	struct device_node *np = pdev->dev.of_node;
510 	struct at91_usbh_data	*pdata;
511 	int			i;
512 	int			ret;
513 	int			err;
514 	u32			ports;
515 
516 	/* Right now device-tree probed devices don't get dma_mask set.
517 	 * Since shared usb code relies on it, set it here for now.
518 	 * Once we have dma capability bindings this can go away.
519 	 */
520 	ret = dma_coerce_mask_and_coherent(&pdev->dev, DMA_BIT_MASK(32));
521 	if (ret)
522 		return ret;
523 
524 	pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
525 	if (!pdata)
526 		return -ENOMEM;
527 
528 	pdev->dev.platform_data = pdata;
529 
530 	if (!of_property_read_u32(np, "num-ports", &ports))
531 		pdata->ports = ports;
532 
533 	at91_for_each_port(i) {
534 		if (i >= pdata->ports)
535 			break;
536 
537 		pdata->vbus_pin[i] =
538 			devm_gpiod_get_index_optional(&pdev->dev, "atmel,vbus",
539 						      i, GPIOD_OUT_HIGH);
540 		if (IS_ERR(pdata->vbus_pin[i])) {
541 			err = PTR_ERR(pdata->vbus_pin[i]);
542 			dev_err(&pdev->dev, "unable to claim gpio \"vbus\": %d\n", err);
543 			continue;
544 		}
545 	}
546 
547 	at91_for_each_port(i) {
548 		if (i >= pdata->ports)
549 			break;
550 
551 		pdata->overcurrent_pin[i] =
552 			devm_gpiod_get_index_optional(&pdev->dev, "atmel,oc",
553 						      i, GPIOD_IN);
554 		if (!pdata->overcurrent_pin[i])
555 			continue;
556 		if (IS_ERR(pdata->overcurrent_pin[i])) {
557 			err = PTR_ERR(pdata->overcurrent_pin[i]);
558 			dev_err(&pdev->dev, "unable to claim gpio \"overcurrent\": %d\n", err);
559 			continue;
560 		}
561 
562 		ret = devm_request_irq(&pdev->dev,
563 				       gpiod_to_irq(pdata->overcurrent_pin[i]),
564 				       ohci_hcd_at91_overcurrent_irq,
565 				       IRQF_SHARED,
566 				       "ohci_overcurrent", pdev);
567 		if (ret)
568 			dev_info(&pdev->dev, "failed to request gpio \"overcurrent\" IRQ\n");
569 	}
570 
571 	device_init_wakeup(&pdev->dev, 1);
572 	return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
573 }
574 
575 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
576 {
577 	struct at91_usbh_data	*pdata = dev_get_platdata(&pdev->dev);
578 	int			i;
579 
580 	if (pdata) {
581 		at91_for_each_port(i)
582 			ohci_at91_usb_set_power(pdata, i, 0);
583 	}
584 
585 	device_init_wakeup(&pdev->dev, 0);
586 	usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
587 	return 0;
588 }
589 
590 static int __maybe_unused
591 ohci_hcd_at91_drv_suspend(struct device *dev)
592 {
593 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
594 	struct ohci_hcd	*ohci = hcd_to_ohci(hcd);
595 	struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
596 	int		ret;
597 
598 	/*
599 	 * Disable wakeup if we are going to sleep with slow clock mode
600 	 * enabled.
601 	 */
602 	ohci_at91->wakeup = device_may_wakeup(dev)
603 			&& !at91_suspend_entering_slow_clock();
604 
605 	if (ohci_at91->wakeup)
606 		enable_irq_wake(hcd->irq);
607 
608 	ohci_at91_port_suspend(ohci_at91->sfr_regmap, 1);
609 
610 	ret = ohci_suspend(hcd, ohci_at91->wakeup);
611 	if (ret) {
612 		if (ohci_at91->wakeup)
613 			disable_irq_wake(hcd->irq);
614 		return ret;
615 	}
616 	/*
617 	 * The integrated transceivers seem unable to notice disconnect,
618 	 * reconnect, or wakeup without the 48 MHz clock active.  so for
619 	 * correctness, always discard connection state (using reset).
620 	 *
621 	 * REVISIT: some boards will be able to turn VBUS off...
622 	 */
623 	if (!ohci_at91->wakeup) {
624 		ohci->rh_state = OHCI_RH_HALTED;
625 
626 		/* flush the writes */
627 		(void) ohci_readl (ohci, &ohci->regs->control);
628 		at91_stop_clock(ohci_at91);
629 	}
630 
631 	return ret;
632 }
633 
634 static int __maybe_unused
635 ohci_hcd_at91_drv_resume(struct device *dev)
636 {
637 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
638 	struct ohci_at91_priv *ohci_at91 = hcd_to_ohci_at91_priv(hcd);
639 
640 	if (ohci_at91->wakeup)
641 		disable_irq_wake(hcd->irq);
642 
643 	at91_start_clock(ohci_at91);
644 
645 	ohci_resume(hcd, false);
646 
647 	ohci_at91_port_suspend(ohci_at91->sfr_regmap, 0);
648 
649 	return 0;
650 }
651 
652 static SIMPLE_DEV_PM_OPS(ohci_hcd_at91_pm_ops, ohci_hcd_at91_drv_suspend,
653 					ohci_hcd_at91_drv_resume);
654 
655 static struct platform_driver ohci_hcd_at91_driver = {
656 	.probe		= ohci_hcd_at91_drv_probe,
657 	.remove		= ohci_hcd_at91_drv_remove,
658 	.shutdown	= usb_hcd_platform_shutdown,
659 	.driver		= {
660 		.name	= "at91_ohci",
661 		.pm	= &ohci_hcd_at91_pm_ops,
662 		.of_match_table	= at91_ohci_dt_ids,
663 	},
664 };
665 
666 static int __init ohci_at91_init(void)
667 {
668 	if (usb_disabled())
669 		return -ENODEV;
670 
671 	pr_info("%s: " DRIVER_DESC "\n", hcd_name);
672 	ohci_init_driver(&ohci_at91_hc_driver, &ohci_at91_drv_overrides);
673 
674 	/*
675 	 * The Atmel HW has some unusual quirks, which require Atmel-specific
676 	 * workarounds. We override certain hc_driver functions here to
677 	 * achieve that. We explicitly do not enhance ohci_driver_overrides to
678 	 * allow this more easily, since this is an unusual case, and we don't
679 	 * want to encourage others to override these functions by making it
680 	 * too easy.
681 	 */
682 
683 	ohci_at91_hc_driver.hub_status_data	= ohci_at91_hub_status_data;
684 	ohci_at91_hc_driver.hub_control		= ohci_at91_hub_control;
685 
686 	return platform_driver_register(&ohci_hcd_at91_driver);
687 }
688 module_init(ohci_at91_init);
689 
690 static void __exit ohci_at91_cleanup(void)
691 {
692 	platform_driver_unregister(&ohci_hcd_at91_driver);
693 }
694 module_exit(ohci_at91_cleanup);
695 
696 MODULE_DESCRIPTION(DRIVER_DESC);
697 MODULE_LICENSE("GPL");
698 MODULE_ALIAS("platform:at91_ohci");
699