Merge branch 'parisc-3.13' of git://git.kernel.org/pub/scm/linux/kernel/git/deller...
[cascardo/linux.git] / drivers / usb / host / ohci-at91.c
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;
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         if (!pdev->dev.dma_mask)
485                 pdev->dev.dma_mask = &pdev->dev.coherent_dma_mask;
486         if (!pdev->dev.coherent_dma_mask)
487                 pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
488
489         pdata = devm_kzalloc(&pdev->dev, sizeof(*pdata), GFP_KERNEL);
490         if (!pdata)
491                 return -ENOMEM;
492
493         if (!of_property_read_u32(np, "num-ports", &ports))
494                 pdata->ports = ports;
495
496         at91_for_each_port(i) {
497                 gpio = of_get_named_gpio_flags(np, "atmel,vbus-gpio", i, &flags);
498                 pdata->vbus_pin[i] = gpio;
499                 if (!gpio_is_valid(gpio))
500                         continue;
501                 pdata->vbus_pin_active_low[i] = flags & OF_GPIO_ACTIVE_LOW;
502         }
503
504         at91_for_each_port(i)
505                 pdata->overcurrent_pin[i] =
506                         of_get_named_gpio_flags(np, "atmel,oc-gpio", i, &flags);
507
508         pdev->dev.platform_data = pdata;
509
510         return 0;
511 }
512 #else
513 static int ohci_at91_of_init(struct platform_device *pdev)
514 {
515         return 0;
516 }
517 #endif
518
519 /*-------------------------------------------------------------------------*/
520
521 static int ohci_hcd_at91_drv_probe(struct platform_device *pdev)
522 {
523         struct at91_usbh_data   *pdata;
524         int                     i;
525         int                     gpio;
526         int                     ret;
527
528         ret = ohci_at91_of_init(pdev);
529         if (ret)
530                 return ret;
531
532         pdata = dev_get_platdata(&pdev->dev);
533
534         if (pdata) {
535                 at91_for_each_port(i) {
536                         /*
537                          * do not configure PIO if not in relation with
538                          * real USB port on board
539                          */
540                         if (i >= pdata->ports) {
541                                 pdata->vbus_pin[i] = -EINVAL;
542                                 pdata->overcurrent_pin[i] = -EINVAL;
543                                 break;
544                         }
545
546                         if (!gpio_is_valid(pdata->vbus_pin[i]))
547                                 continue;
548                         gpio = pdata->vbus_pin[i];
549
550                         ret = gpio_request(gpio, "ohci_vbus");
551                         if (ret) {
552                                 dev_err(&pdev->dev,
553                                         "can't request vbus gpio %d\n", gpio);
554                                 continue;
555                         }
556                         ret = gpio_direction_output(gpio,
557                                                 !pdata->vbus_pin_active_low[i]);
558                         if (ret) {
559                                 dev_err(&pdev->dev,
560                                         "can't put vbus gpio %d as output %d\n",
561                                         gpio, !pdata->vbus_pin_active_low[i]);
562                                 gpio_free(gpio);
563                                 continue;
564                         }
565
566                         ohci_at91_usb_set_power(pdata, i, 1);
567                 }
568
569                 at91_for_each_port(i) {
570                         if (!gpio_is_valid(pdata->overcurrent_pin[i]))
571                                 continue;
572                         gpio = pdata->overcurrent_pin[i];
573
574                         ret = gpio_request(gpio, "ohci_overcurrent");
575                         if (ret) {
576                                 dev_err(&pdev->dev,
577                                         "can't request overcurrent gpio %d\n",
578                                         gpio);
579                                 continue;
580                         }
581
582                         ret = gpio_direction_input(gpio);
583                         if (ret) {
584                                 dev_err(&pdev->dev,
585                                         "can't configure overcurrent gpio %d as input\n",
586                                         gpio);
587                                 gpio_free(gpio);
588                                 continue;
589                         }
590
591                         ret = request_irq(gpio_to_irq(gpio),
592                                           ohci_hcd_at91_overcurrent_irq,
593                                           IRQF_SHARED, "ohci_overcurrent", pdev);
594                         if (ret) {
595                                 gpio_free(gpio);
596                                 dev_err(&pdev->dev,
597                                         "can't get gpio IRQ for overcurrent\n");
598                         }
599                 }
600         }
601
602         device_init_wakeup(&pdev->dev, 1);
603         return usb_hcd_at91_probe(&ohci_at91_hc_driver, pdev);
604 }
605
606 static int ohci_hcd_at91_drv_remove(struct platform_device *pdev)
607 {
608         struct at91_usbh_data   *pdata = dev_get_platdata(&pdev->dev);
609         int                     i;
610
611         if (pdata) {
612                 at91_for_each_port(i) {
613                         if (!gpio_is_valid(pdata->vbus_pin[i]))
614                                 continue;
615                         ohci_at91_usb_set_power(pdata, i, 0);
616                         gpio_free(pdata->vbus_pin[i]);
617                 }
618
619                 at91_for_each_port(i) {
620                         if (!gpio_is_valid(pdata->overcurrent_pin[i]))
621                                 continue;
622                         free_irq(gpio_to_irq(pdata->overcurrent_pin[i]), pdev);
623                         gpio_free(pdata->overcurrent_pin[i]);
624                 }
625         }
626
627         device_init_wakeup(&pdev->dev, 0);
628         usb_hcd_at91_remove(platform_get_drvdata(pdev), pdev);
629         return 0;
630 }
631
632 #ifdef CONFIG_PM
633
634 static int
635 ohci_hcd_at91_drv_suspend(struct platform_device *pdev, pm_message_t mesg)
636 {
637         struct usb_hcd  *hcd = platform_get_drvdata(pdev);
638         struct ohci_hcd *ohci = hcd_to_ohci(hcd);
639
640         if (device_may_wakeup(&pdev->dev))
641                 enable_irq_wake(hcd->irq);
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 (at91_suspend_entering_slow_clock()) {
651                 ohci->hc_control = ohci_readl(ohci, &ohci->regs->control);
652                 ohci->hc_control &= OHCI_CTRL_RWC;
653                 ohci_writel(ohci, ohci->hc_control, &ohci->regs->control);
654                 ohci->rh_state = OHCI_RH_HALTED;
655
656                 /* flush the writes */
657                 (void) ohci_readl (ohci, &ohci->regs->control);
658                 at91_stop_clock();
659         }
660
661         return 0;
662 }
663
664 static int ohci_hcd_at91_drv_resume(struct platform_device *pdev)
665 {
666         struct usb_hcd  *hcd = platform_get_drvdata(pdev);
667
668         if (device_may_wakeup(&pdev->dev))
669                 disable_irq_wake(hcd->irq);
670
671         if (!clocked)
672                 at91_start_clock();
673
674         ohci_resume(hcd, false);
675         return 0;
676 }
677 #else
678 #define ohci_hcd_at91_drv_suspend NULL
679 #define ohci_hcd_at91_drv_resume  NULL
680 #endif
681
682 static struct platform_driver ohci_hcd_at91_driver = {
683         .probe          = ohci_hcd_at91_drv_probe,
684         .remove         = ohci_hcd_at91_drv_remove,
685         .shutdown       = usb_hcd_platform_shutdown,
686         .suspend        = ohci_hcd_at91_drv_suspend,
687         .resume         = ohci_hcd_at91_drv_resume,
688         .driver         = {
689                 .name   = "at91_ohci",
690                 .owner  = THIS_MODULE,
691                 .of_match_table = of_match_ptr(at91_ohci_dt_ids),
692         },
693 };
694
695 static int __init ohci_at91_init(void)
696 {
697         if (usb_disabled())
698                 return -ENODEV;
699
700         pr_info("%s: " DRIVER_DESC "\n", hcd_name);
701         ohci_init_driver(&ohci_at91_hc_driver, NULL);
702
703         /*
704          * The Atmel HW has some unusual quirks, which require Atmel-specific
705          * workarounds. We override certain hc_driver functions here to
706          * achieve that. We explicitly do not enhance ohci_driver_overrides to
707          * allow this more easily, since this is an unusual case, and we don't
708          * want to encourage others to override these functions by making it
709          * too easy.
710          */
711
712         orig_ohci_hub_control = ohci_at91_hc_driver.hub_control;
713         orig_ohci_hub_status_data = ohci_at91_hc_driver.hub_status_data;
714
715         ohci_at91_hc_driver.hub_status_data     = ohci_at91_hub_status_data;
716         ohci_at91_hc_driver.hub_control         = ohci_at91_hub_control;
717
718         return platform_driver_register(&ohci_hcd_at91_driver);
719 }
720 module_init(ohci_at91_init);
721
722 static void __exit ohci_at91_cleanup(void)
723 {
724         platform_driver_unregister(&ohci_hcd_at91_driver);
725 }
726 module_exit(ohci_at91_cleanup);
727
728 MODULE_DESCRIPTION(DRIVER_DESC);
729 MODULE_LICENSE("GPL");
730 MODULE_ALIAS("platform:at91_ohci");