xref: /linux/drivers/usb/host/xhci-plat.c (revision 68a052239fc4b351e961f698b824f7654a346091)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * xhci-plat.c - xHCI host controller driver platform Bus Glue.
4  *
5  * Copyright (C) 2012 Texas Instruments Incorporated - https://www.ti.com
6  * Author: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
7  *
8  * A lot of code borrowed from the Linux xHCI driver.
9  */
10 
11 #include <linux/clk.h>
12 #include <linux/dma-mapping.h>
13 #include <linux/module.h>
14 #include <linux/pci.h>
15 #include <linux/of.h>
16 #include <linux/of_device.h>
17 #include <linux/platform_device.h>
18 #include <linux/usb/phy.h>
19 #include <linux/slab.h>
20 #include <linux/acpi.h>
21 #include <linux/usb/of.h>
22 #include <linux/reset.h>
23 #include <linux/usb/xhci-sideband.h>
24 
25 #include "xhci.h"
26 #include "xhci-plat.h"
27 #include "xhci-mvebu.h"
28 
29 static struct hc_driver __read_mostly xhci_plat_hc_driver;
30 
31 static int xhci_plat_setup(struct usb_hcd *hcd);
32 static int xhci_plat_start(struct usb_hcd *hcd);
33 
34 static const struct xhci_driver_overrides xhci_plat_overrides __initconst = {
35 	.extra_priv_size = sizeof(struct xhci_plat_priv),
36 	.reset = xhci_plat_setup,
37 	.start = xhci_plat_start,
38 };
39 
40 static void xhci_priv_plat_start(struct usb_hcd *hcd)
41 {
42 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
43 
44 	if (priv->plat_start)
45 		priv->plat_start(hcd);
46 }
47 
48 static int xhci_priv_init_quirk(struct usb_hcd *hcd)
49 {
50 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
51 
52 	if (!priv->init_quirk)
53 		return 0;
54 
55 	return priv->init_quirk(hcd);
56 }
57 
58 static int xhci_priv_suspend_quirk(struct usb_hcd *hcd)
59 {
60 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
61 
62 	if (!priv->suspend_quirk)
63 		return 0;
64 
65 	return priv->suspend_quirk(hcd);
66 }
67 
68 static int xhci_priv_resume_quirk(struct usb_hcd *hcd)
69 {
70 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
71 
72 	if (!priv->resume_quirk)
73 		return 0;
74 
75 	return priv->resume_quirk(hcd);
76 }
77 
78 static int xhci_priv_post_resume_quirk(struct usb_hcd *hcd)
79 {
80 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
81 
82 	if (!priv->post_resume_quirk)
83 		return 0;
84 
85 	return priv->post_resume_quirk(hcd);
86 }
87 
88 static void xhci_plat_quirks(struct device *dev, struct xhci_hcd *xhci)
89 {
90 	struct xhci_plat_priv *priv = xhci_to_priv(xhci);
91 
92 	xhci->quirks |= priv->quirks;
93 }
94 
95 /* called during probe() after chip reset completes */
96 static int xhci_plat_setup(struct usb_hcd *hcd)
97 {
98 	int ret;
99 
100 
101 	ret = xhci_priv_init_quirk(hcd);
102 	if (ret)
103 		return ret;
104 
105 	return xhci_gen_setup(hcd, xhci_plat_quirks);
106 }
107 
108 static int xhci_plat_start(struct usb_hcd *hcd)
109 {
110 	xhci_priv_plat_start(hcd);
111 	return xhci_run(hcd);
112 }
113 
114 #ifdef CONFIG_OF
115 static const struct xhci_plat_priv xhci_plat_marvell_armada = {
116 	.init_quirk = xhci_mvebu_mbus_init_quirk,
117 };
118 
119 static const struct xhci_plat_priv xhci_plat_marvell_armada3700 = {
120 	.quirks = XHCI_RESET_ON_RESUME,
121 };
122 
123 static const struct xhci_plat_priv xhci_plat_brcm = {
124 	.quirks = XHCI_RESET_ON_RESUME | XHCI_SUSPEND_RESUME_CLKS,
125 };
126 
127 static const struct of_device_id usb_xhci_of_match[] = {
128 	{
129 		.compatible = "generic-xhci",
130 	}, {
131 		.compatible = "xhci-platform",
132 	}, {
133 		.compatible = "marvell,armada-375-xhci",
134 		.data = &xhci_plat_marvell_armada,
135 	}, {
136 		.compatible = "marvell,armada-380-xhci",
137 		.data = &xhci_plat_marvell_armada,
138 	}, {
139 		.compatible = "marvell,armada3700-xhci",
140 		.data = &xhci_plat_marvell_armada3700,
141 	}, {
142 		.compatible = "brcm,xhci-brcm-v2",
143 		.data = &xhci_plat_brcm,
144 	}, {
145 		.compatible = "brcm,bcm2711-xhci",
146 		.data = &xhci_plat_brcm,
147 	}, {
148 		.compatible = "brcm,bcm7445-xhci",
149 		.data = &xhci_plat_brcm,
150 	},
151 	{},
152 };
153 MODULE_DEVICE_TABLE(of, usb_xhci_of_match);
154 #endif
155 
156 int xhci_plat_probe(struct platform_device *pdev, struct device *sysdev, const struct xhci_plat_priv *priv_match)
157 {
158 	const struct hc_driver	*driver;
159 	struct device		*tmpdev;
160 	struct xhci_hcd		*xhci;
161 	struct resource         *res;
162 	struct usb_hcd		*hcd, *usb3_hcd;
163 	int			ret;
164 	int			irq;
165 	struct xhci_plat_priv	*priv = NULL;
166 	const struct of_device_id *of_match;
167 
168 	if (usb_disabled())
169 		return -ENODEV;
170 
171 	driver = &xhci_plat_hc_driver;
172 
173 	irq = platform_get_irq(pdev, 0);
174 	if (irq < 0)
175 		return irq;
176 
177 	if (!sysdev)
178 		sysdev = &pdev->dev;
179 
180 	ret = dma_set_mask_and_coherent(sysdev, DMA_BIT_MASK(64));
181 	if (ret)
182 		return ret;
183 
184 	pm_runtime_set_active(&pdev->dev);
185 	pm_runtime_use_autosuspend(&pdev->dev);
186 	pm_runtime_enable(&pdev->dev);
187 	pm_runtime_get_noresume(&pdev->dev);
188 
189 	hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
190 			       dev_name(&pdev->dev), NULL);
191 	if (!hcd) {
192 		ret = -ENOMEM;
193 		goto disable_runtime;
194 	}
195 
196 	hcd->regs = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
197 	if (IS_ERR(hcd->regs)) {
198 		ret = PTR_ERR(hcd->regs);
199 		goto put_hcd;
200 	}
201 
202 	hcd->rsrc_start = res->start;
203 	hcd->rsrc_len = resource_size(res);
204 
205 	xhci = hcd_to_xhci(hcd);
206 
207 	xhci->allow_single_roothub = 1;
208 
209 	/*
210 	 * Not all platforms have clks so it is not an error if the
211 	 * clock do not exist.
212 	 */
213 	xhci->reg_clk = devm_clk_get_optional(&pdev->dev, "reg");
214 	if (IS_ERR(xhci->reg_clk)) {
215 		ret = PTR_ERR(xhci->reg_clk);
216 		goto put_hcd;
217 	}
218 
219 	xhci->clk = devm_clk_get_optional(&pdev->dev, NULL);
220 	if (IS_ERR(xhci->clk)) {
221 		ret = PTR_ERR(xhci->clk);
222 		goto put_hcd;
223 	}
224 
225 	xhci->reset = devm_reset_control_array_get_optional_shared(&pdev->dev);
226 	if (IS_ERR(xhci->reset)) {
227 		ret = PTR_ERR(xhci->reset);
228 		goto put_hcd;
229 	}
230 
231 	ret = reset_control_deassert(xhci->reset);
232 	if (ret)
233 		goto put_hcd;
234 
235 	ret = clk_prepare_enable(xhci->reg_clk);
236 	if (ret)
237 		goto err_reset;
238 
239 	ret = clk_prepare_enable(xhci->clk);
240 	if (ret)
241 		goto disable_reg_clk;
242 
243 	if (priv_match) {
244 		priv = hcd_to_xhci_priv(hcd);
245 		/* Just copy data for now */
246 		*priv = *priv_match;
247 	}
248 
249 	device_set_wakeup_capable(&pdev->dev, true);
250 
251 	xhci->main_hcd = hcd;
252 
253 	/* imod_interval is the interrupt moderation value in nanoseconds. */
254 	xhci->imod_interval = 40000;
255 
256 	/* Iterate over all parent nodes for finding quirks */
257 	for (tmpdev = &pdev->dev; tmpdev; tmpdev = tmpdev->parent) {
258 
259 		if (device_property_read_bool(tmpdev, "usb2-lpm-disable"))
260 			xhci->quirks |= XHCI_HW_LPM_DISABLE;
261 
262 		if (device_property_read_bool(tmpdev, "usb3-lpm-capable"))
263 			xhci->quirks |= XHCI_LPM_SUPPORT;
264 
265 		if (device_property_read_bool(tmpdev, "quirk-broken-port-ped"))
266 			xhci->quirks |= XHCI_BROKEN_PORT_PED;
267 
268 		if (device_property_read_bool(tmpdev, "xhci-sg-trb-cache-size-quirk"))
269 			xhci->quirks |= XHCI_SG_TRB_CACHE_SIZE_QUIRK;
270 
271 		if (device_property_read_bool(tmpdev, "write-64-hi-lo-quirk"))
272 			xhci->quirks |= XHCI_WRITE_64_HI_LO;
273 
274 		if (device_property_read_bool(tmpdev, "xhci-missing-cas-quirk"))
275 			xhci->quirks |= XHCI_MISSING_CAS;
276 
277 		if (device_property_read_bool(tmpdev, "xhci-skip-phy-init-quirk"))
278 			xhci->quirks |= XHCI_SKIP_PHY_INIT;
279 
280 		device_property_read_u32(tmpdev, "imod-interval-ns",
281 					 &xhci->imod_interval);
282 		device_property_read_u16(tmpdev, "num-hc-interrupters",
283 					 &xhci->max_interrupters);
284 	}
285 
286 	/*
287 	 * Drivers such as dwc3 manages PHYs themself (and rely on driver name
288 	 * matching for the xhci platform device).
289 	 */
290 	of_match = of_match_device(pdev->dev.driver->of_match_table, &pdev->dev);
291 	if (of_match) {
292 		hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev, "usb-phy", 0);
293 		if (IS_ERR(hcd->usb_phy)) {
294 			ret = PTR_ERR(hcd->usb_phy);
295 			if (ret == -EPROBE_DEFER)
296 				goto disable_clk;
297 			hcd->usb_phy = NULL;
298 		} else {
299 			ret = usb_phy_init(hcd->usb_phy);
300 			if (ret)
301 				goto disable_clk;
302 		}
303 	}
304 
305 	hcd->tpl_support = of_usb_host_tpl_support(sysdev->of_node);
306 
307 	if ((priv && (priv->quirks & XHCI_SKIP_PHY_INIT)) ||
308 	    (xhci->quirks & XHCI_SKIP_PHY_INIT))
309 		hcd->skip_phy_initialization = 1;
310 
311 	if (priv && (priv->quirks & XHCI_SG_TRB_CACHE_SIZE_QUIRK))
312 		xhci->quirks |= XHCI_SG_TRB_CACHE_SIZE_QUIRK;
313 
314 	ret = usb_add_hcd(hcd, irq, IRQF_SHARED);
315 	if (ret)
316 		goto disable_usb_phy;
317 
318 	if (!xhci_has_one_roothub(xhci)) {
319 		xhci->shared_hcd = __usb_create_hcd(driver, sysdev, &pdev->dev,
320 						    dev_name(&pdev->dev), hcd);
321 		if (!xhci->shared_hcd) {
322 			ret = -ENOMEM;
323 			goto dealloc_usb2_hcd;
324 		}
325 
326 		if (of_match) {
327 			xhci->shared_hcd->usb_phy = devm_usb_get_phy_by_phandle(sysdev,
328 										"usb-phy", 1);
329 			if (IS_ERR(xhci->shared_hcd->usb_phy)) {
330 				xhci->shared_hcd->usb_phy = NULL;
331 			} else {
332 				ret = usb_phy_init(xhci->shared_hcd->usb_phy);
333 				if (ret)
334 					dev_err(sysdev, "%s init usb3phy fail (ret=%d)\n",
335 						__func__, ret);
336 			}
337 		}
338 
339 		xhci->shared_hcd->tpl_support = hcd->tpl_support;
340 	}
341 
342 	usb3_hcd = xhci_get_usb3_hcd(xhci);
343 	if (usb3_hcd && HCC_MAX_PSA(xhci->hcc_params) >= 4 &&
344 	    !(xhci->quirks & XHCI_BROKEN_STREAMS))
345 		usb3_hcd->can_do_streams = 1;
346 
347 	if (xhci->shared_hcd) {
348 		xhci->shared_hcd->rsrc_start = hcd->rsrc_start;
349 		xhci->shared_hcd->rsrc_len = hcd->rsrc_len;
350 		ret = usb_add_hcd(xhci->shared_hcd, irq, IRQF_SHARED);
351 		if (ret)
352 			goto put_usb3_hcd;
353 	}
354 
355 	device_enable_async_suspend(&pdev->dev);
356 	pm_runtime_put_noidle(&pdev->dev);
357 
358 	/*
359 	 * Prevent runtime pm from being on as default, users should enable
360 	 * runtime pm using power/control in sysfs.
361 	 */
362 	pm_runtime_forbid(&pdev->dev);
363 
364 	return 0;
365 
366 
367 put_usb3_hcd:
368 	usb_put_hcd(xhci->shared_hcd);
369 
370 dealloc_usb2_hcd:
371 	usb_remove_hcd(hcd);
372 
373 disable_usb_phy:
374 	usb_phy_shutdown(hcd->usb_phy);
375 
376 disable_clk:
377 	clk_disable_unprepare(xhci->clk);
378 
379 disable_reg_clk:
380 	clk_disable_unprepare(xhci->reg_clk);
381 
382 err_reset:
383 	reset_control_assert(xhci->reset);
384 
385 put_hcd:
386 	usb_put_hcd(hcd);
387 
388 disable_runtime:
389 	pm_runtime_put_noidle(&pdev->dev);
390 	pm_runtime_disable(&pdev->dev);
391 
392 	return ret;
393 }
394 EXPORT_SYMBOL_GPL(xhci_plat_probe);
395 
396 static int xhci_generic_plat_probe(struct platform_device *pdev)
397 {
398 	const struct xhci_plat_priv *priv_match;
399 	struct device *sysdev;
400 	int ret;
401 
402 	/*
403 	 * sysdev must point to a device that is known to the system firmware
404 	 * or PCI hardware. We handle these three cases here:
405 	 * 1. xhci_plat comes from firmware
406 	 * 2. xhci_plat is child of a device from firmware (dwc3-plat)
407 	 * 3. xhci_plat is grandchild of a pci device (dwc3-pci)
408 	 */
409 	for (sysdev = &pdev->dev; sysdev; sysdev = sysdev->parent) {
410 		if (is_of_node(sysdev->fwnode) ||
411 			is_acpi_device_node(sysdev->fwnode))
412 			break;
413 		else if (dev_is_pci(sysdev))
414 			break;
415 	}
416 
417 	if (!sysdev)
418 		sysdev = &pdev->dev;
419 
420 	if (WARN_ON(!sysdev->dma_mask)) {
421 		/* Platform did not initialize dma_mask */
422 		ret = dma_coerce_mask_and_coherent(sysdev, DMA_BIT_MASK(64));
423 		if (ret)
424 			return ret;
425 	}
426 
427 	if (pdev->dev.of_node)
428 		priv_match = of_device_get_match_data(&pdev->dev);
429 	else
430 		priv_match = dev_get_platdata(&pdev->dev);
431 
432 	return xhci_plat_probe(pdev, sysdev, priv_match);
433 }
434 
435 void xhci_plat_remove(struct platform_device *dev)
436 {
437 	struct usb_hcd	*hcd = platform_get_drvdata(dev);
438 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
439 	struct clk *clk = xhci->clk;
440 	struct clk *reg_clk = xhci->reg_clk;
441 	struct usb_hcd *shared_hcd = xhci->shared_hcd;
442 
443 	xhci->xhc_state |= XHCI_STATE_REMOVING;
444 	pm_runtime_get_sync(&dev->dev);
445 
446 	if (shared_hcd) {
447 		usb_remove_hcd(shared_hcd);
448 		xhci->shared_hcd = NULL;
449 	}
450 
451 	usb_phy_shutdown(hcd->usb_phy);
452 
453 	usb_remove_hcd(hcd);
454 
455 	if (shared_hcd)
456 		usb_put_hcd(shared_hcd);
457 
458 	clk_disable_unprepare(clk);
459 	clk_disable_unprepare(reg_clk);
460 	reset_control_assert(xhci->reset);
461 	usb_put_hcd(hcd);
462 
463 	pm_runtime_disable(&dev->dev);
464 	pm_runtime_put_noidle(&dev->dev);
465 	pm_runtime_set_suspended(&dev->dev);
466 }
467 EXPORT_SYMBOL_GPL(xhci_plat_remove);
468 
469 static int xhci_plat_suspend_common(struct device *dev)
470 {
471 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
472 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
473 	int ret;
474 
475 	if (pm_runtime_suspended(dev))
476 		pm_runtime_resume(dev);
477 
478 	ret = xhci_priv_suspend_quirk(hcd);
479 	if (ret)
480 		return ret;
481 	/*
482 	 * xhci_suspend() needs `do_wakeup` to know whether host is allowed
483 	 * to do wakeup during suspend.
484 	 */
485 	ret = xhci_suspend(xhci, device_may_wakeup(dev));
486 	if (ret)
487 		return ret;
488 
489 	if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) {
490 		clk_disable_unprepare(xhci->clk);
491 		clk_disable_unprepare(xhci->reg_clk);
492 	}
493 
494 	return 0;
495 }
496 
497 static int xhci_plat_suspend(struct device *dev)
498 {
499 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
500 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
501 
502 	if (xhci_sideband_check(hcd)) {
503 		priv->sideband_at_suspend = 1;
504 		dev_dbg(dev, "sideband instance active, skip suspend.\n");
505 		return 0;
506 	}
507 
508 	return xhci_plat_suspend_common(dev);
509 }
510 
511 static int xhci_plat_freeze(struct device *dev)
512 {
513 	return xhci_plat_suspend_common(dev);
514 }
515 
516 static int xhci_plat_resume_common(struct device *dev, bool power_lost)
517 {
518 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
519 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
520 	struct xhci_hcd	*xhci = hcd_to_xhci(hcd);
521 	int ret;
522 
523 	if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) {
524 		ret = clk_prepare_enable(xhci->clk);
525 		if (ret)
526 			return ret;
527 
528 		ret = clk_prepare_enable(xhci->reg_clk);
529 		if (ret) {
530 			clk_disable_unprepare(xhci->clk);
531 			return ret;
532 		}
533 	}
534 
535 	ret = xhci_priv_resume_quirk(hcd);
536 	if (ret)
537 		goto disable_clks;
538 
539 	ret = xhci_resume(xhci, power_lost || priv->power_lost, false);
540 	if (ret)
541 		goto disable_clks;
542 
543 	ret = xhci_priv_post_resume_quirk(hcd);
544 	if (ret)
545 		goto disable_clks;
546 
547 	pm_runtime_disable(dev);
548 	pm_runtime_set_active(dev);
549 	pm_runtime_enable(dev);
550 
551 	return 0;
552 
553 disable_clks:
554 	if (!device_may_wakeup(dev) && (xhci->quirks & XHCI_SUSPEND_RESUME_CLKS)) {
555 		clk_disable_unprepare(xhci->clk);
556 		clk_disable_unprepare(xhci->reg_clk);
557 	}
558 
559 	return ret;
560 }
561 
562 static int xhci_plat_resume(struct device *dev)
563 {
564 	struct usb_hcd	*hcd = dev_get_drvdata(dev);
565 	struct xhci_plat_priv *priv = hcd_to_xhci_priv(hcd);
566 
567 	if (priv->sideband_at_suspend) {
568 		priv->sideband_at_suspend = 0;
569 		dev_dbg(dev, "sideband instance active, skip resume.\n");
570 		return 0;
571 	}
572 
573 	return xhci_plat_resume_common(dev, false);
574 }
575 
576 static int xhci_plat_thaw(struct device *dev)
577 {
578 	return xhci_plat_resume_common(dev, false);
579 }
580 
581 static int xhci_plat_restore(struct device *dev)
582 {
583 	return xhci_plat_resume_common(dev, true);
584 }
585 
586 static int __maybe_unused xhci_plat_runtime_suspend(struct device *dev)
587 {
588 	struct usb_hcd  *hcd = dev_get_drvdata(dev);
589 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
590 	int ret;
591 
592 	ret = xhci_priv_suspend_quirk(hcd);
593 	if (ret)
594 		return ret;
595 
596 	return xhci_suspend(xhci, true);
597 }
598 
599 static int __maybe_unused xhci_plat_runtime_resume(struct device *dev)
600 {
601 	struct usb_hcd  *hcd = dev_get_drvdata(dev);
602 	struct xhci_hcd *xhci = hcd_to_xhci(hcd);
603 
604 	return xhci_resume(xhci, false, true);
605 }
606 
607 const struct dev_pm_ops xhci_plat_pm_ops = {
608 	.suspend = pm_sleep_ptr(xhci_plat_suspend),
609 	.resume = pm_sleep_ptr(xhci_plat_resume),
610 	.freeze = pm_sleep_ptr(xhci_plat_freeze),
611 	.thaw = pm_sleep_ptr(xhci_plat_thaw),
612 	.poweroff = pm_sleep_ptr(xhci_plat_freeze),
613 	.restore = pm_sleep_ptr(xhci_plat_restore),
614 
615 	SET_RUNTIME_PM_OPS(xhci_plat_runtime_suspend,
616 			   xhci_plat_runtime_resume,
617 			   NULL)
618 };
619 EXPORT_SYMBOL_GPL(xhci_plat_pm_ops);
620 
621 #ifdef CONFIG_ACPI
622 static const struct acpi_device_id usb_xhci_acpi_match[] = {
623 	/* XHCI-compliant USB Controller */
624 	{ "PNP0D10", },
625 	{ "PNP0D15", },
626 	{ }
627 };
628 MODULE_DEVICE_TABLE(acpi, usb_xhci_acpi_match);
629 #endif
630 
631 static struct platform_driver usb_generic_xhci_driver = {
632 	.probe	= xhci_generic_plat_probe,
633 	.remove = xhci_plat_remove,
634 	.shutdown = usb_hcd_platform_shutdown,
635 	.driver	= {
636 		.name = "xhci-hcd",
637 		.pm = &xhci_plat_pm_ops,
638 		.of_match_table = of_match_ptr(usb_xhci_of_match),
639 		.acpi_match_table = ACPI_PTR(usb_xhci_acpi_match),
640 	},
641 };
642 MODULE_ALIAS("platform:xhci-hcd");
643 
644 static int __init xhci_plat_init(void)
645 {
646 	xhci_init_driver(&xhci_plat_hc_driver, &xhci_plat_overrides);
647 	return platform_driver_register(&usb_generic_xhci_driver);
648 }
649 module_init(xhci_plat_init);
650 
651 static void __exit xhci_plat_exit(void)
652 {
653 	platform_driver_unregister(&usb_generic_xhci_driver);
654 }
655 module_exit(xhci_plat_exit);
656 
657 MODULE_DESCRIPTION("xHCI Platform Host Controller Driver");
658 MODULE_LICENSE("GPL");
659