xref: /linux/drivers/base/platform.c (revision 5bdef865eb358b6f3760e25e591ae115e9eeddef)
1 /*
2  * platform.c - platform 'pseudo' bus for legacy devices
3  *
4  * Copyright (c) 2002-3 Patrick Mochel
5  * Copyright (c) 2002-3 Open Source Development Labs
6  *
7  * This file is released under the GPLv2
8  *
9  * Please see Documentation/driver-model/platform.txt for more
10  * information.
11  */
12 
13 #include <linux/platform_device.h>
14 #include <linux/module.h>
15 #include <linux/init.h>
16 #include <linux/dma-mapping.h>
17 #include <linux/bootmem.h>
18 #include <linux/err.h>
19 #include <linux/slab.h>
20 
21 #include "base.h"
22 
23 #define to_platform_driver(drv)	(container_of((drv), struct platform_driver, \
24 				 driver))
25 
26 struct device platform_bus = {
27 	.init_name	= "platform",
28 };
29 EXPORT_SYMBOL_GPL(platform_bus);
30 
31 /**
32  * platform_get_resource - get a resource for a device
33  * @dev: platform device
34  * @type: resource type
35  * @num: resource index
36  */
37 struct resource *platform_get_resource(struct platform_device *dev,
38 				       unsigned int type, unsigned int num)
39 {
40 	int i;
41 
42 	for (i = 0; i < dev->num_resources; i++) {
43 		struct resource *r = &dev->resource[i];
44 
45 		if (type == resource_type(r) && num-- == 0)
46 			return r;
47 	}
48 	return NULL;
49 }
50 EXPORT_SYMBOL_GPL(platform_get_resource);
51 
52 /**
53  * platform_get_irq - get an IRQ for a device
54  * @dev: platform device
55  * @num: IRQ number index
56  */
57 int platform_get_irq(struct platform_device *dev, unsigned int num)
58 {
59 	struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
60 
61 	return r ? r->start : -ENXIO;
62 }
63 EXPORT_SYMBOL_GPL(platform_get_irq);
64 
65 /**
66  * platform_get_resource_byname - get a resource for a device by name
67  * @dev: platform device
68  * @type: resource type
69  * @name: resource name
70  */
71 struct resource *platform_get_resource_byname(struct platform_device *dev,
72 					      unsigned int type,
73 					      const char *name)
74 {
75 	int i;
76 
77 	for (i = 0; i < dev->num_resources; i++) {
78 		struct resource *r = &dev->resource[i];
79 
80 		if (type == resource_type(r) && !strcmp(r->name, name))
81 			return r;
82 	}
83 	return NULL;
84 }
85 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
86 
87 /**
88  * platform_get_irq - get an IRQ for a device
89  * @dev: platform device
90  * @name: IRQ name
91  */
92 int platform_get_irq_byname(struct platform_device *dev, const char *name)
93 {
94 	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
95 							  name);
96 
97 	return r ? r->start : -ENXIO;
98 }
99 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
100 
101 /**
102  * platform_add_devices - add a numbers of platform devices
103  * @devs: array of platform devices to add
104  * @num: number of platform devices in array
105  */
106 int platform_add_devices(struct platform_device **devs, int num)
107 {
108 	int i, ret = 0;
109 
110 	for (i = 0; i < num; i++) {
111 		ret = platform_device_register(devs[i]);
112 		if (ret) {
113 			while (--i >= 0)
114 				platform_device_unregister(devs[i]);
115 			break;
116 		}
117 	}
118 
119 	return ret;
120 }
121 EXPORT_SYMBOL_GPL(platform_add_devices);
122 
123 struct platform_object {
124 	struct platform_device pdev;
125 	char name[1];
126 };
127 
128 /**
129  * platform_device_put
130  * @pdev: platform device to free
131  *
132  * Free all memory associated with a platform device.  This function must
133  * _only_ be externally called in error cases.  All other usage is a bug.
134  */
135 void platform_device_put(struct platform_device *pdev)
136 {
137 	if (pdev)
138 		put_device(&pdev->dev);
139 }
140 EXPORT_SYMBOL_GPL(platform_device_put);
141 
142 static void platform_device_release(struct device *dev)
143 {
144 	struct platform_object *pa = container_of(dev, struct platform_object,
145 						  pdev.dev);
146 
147 	kfree(pa->pdev.dev.platform_data);
148 	kfree(pa->pdev.resource);
149 	kfree(pa);
150 }
151 
152 /**
153  * platform_device_alloc
154  * @name: base name of the device we're adding
155  * @id: instance id
156  *
157  * Create a platform device object which can have other objects attached
158  * to it, and which will have attached objects freed when it is released.
159  */
160 struct platform_device *platform_device_alloc(const char *name, int id)
161 {
162 	struct platform_object *pa;
163 
164 	pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
165 	if (pa) {
166 		strcpy(pa->name, name);
167 		pa->pdev.name = pa->name;
168 		pa->pdev.id = id;
169 		device_initialize(&pa->pdev.dev);
170 		pa->pdev.dev.release = platform_device_release;
171 	}
172 
173 	return pa ? &pa->pdev : NULL;
174 }
175 EXPORT_SYMBOL_GPL(platform_device_alloc);
176 
177 /**
178  * platform_device_add_resources
179  * @pdev: platform device allocated by platform_device_alloc to add resources to
180  * @res: set of resources that needs to be allocated for the device
181  * @num: number of resources
182  *
183  * Add a copy of the resources to the platform device.  The memory
184  * associated with the resources will be freed when the platform device is
185  * released.
186  */
187 int platform_device_add_resources(struct platform_device *pdev,
188 				  struct resource *res, unsigned int num)
189 {
190 	struct resource *r;
191 
192 	r = kmalloc(sizeof(struct resource) * num, GFP_KERNEL);
193 	if (r) {
194 		memcpy(r, res, sizeof(struct resource) * num);
195 		pdev->resource = r;
196 		pdev->num_resources = num;
197 	}
198 	return r ? 0 : -ENOMEM;
199 }
200 EXPORT_SYMBOL_GPL(platform_device_add_resources);
201 
202 /**
203  * platform_device_add_data
204  * @pdev: platform device allocated by platform_device_alloc to add resources to
205  * @data: platform specific data for this platform device
206  * @size: size of platform specific data
207  *
208  * Add a copy of platform specific data to the platform device's
209  * platform_data pointer.  The memory associated with the platform data
210  * will be freed when the platform device is released.
211  */
212 int platform_device_add_data(struct platform_device *pdev, const void *data,
213 			     size_t size)
214 {
215 	void *d;
216 
217 	d = kmalloc(size, GFP_KERNEL);
218 	if (d) {
219 		memcpy(d, data, size);
220 		pdev->dev.platform_data = d;
221 	}
222 	return d ? 0 : -ENOMEM;
223 }
224 EXPORT_SYMBOL_GPL(platform_device_add_data);
225 
226 /**
227  * platform_device_add - add a platform device to device hierarchy
228  * @pdev: platform device we're adding
229  *
230  * This is part 2 of platform_device_register(), though may be called
231  * separately _iff_ pdev was allocated by platform_device_alloc().
232  */
233 int platform_device_add(struct platform_device *pdev)
234 {
235 	int i, ret = 0;
236 
237 	if (!pdev)
238 		return -EINVAL;
239 
240 	if (!pdev->dev.parent)
241 		pdev->dev.parent = &platform_bus;
242 
243 	pdev->dev.bus = &platform_bus_type;
244 
245 	if (pdev->id != -1)
246 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
247 	else
248 		dev_set_name(&pdev->dev, "%s", pdev->name);
249 
250 	for (i = 0; i < pdev->num_resources; i++) {
251 		struct resource *p, *r = &pdev->resource[i];
252 
253 		if (r->name == NULL)
254 			r->name = dev_name(&pdev->dev);
255 
256 		p = r->parent;
257 		if (!p) {
258 			if (resource_type(r) == IORESOURCE_MEM)
259 				p = &iomem_resource;
260 			else if (resource_type(r) == IORESOURCE_IO)
261 				p = &ioport_resource;
262 		}
263 
264 		if (p && insert_resource(p, r)) {
265 			printk(KERN_ERR
266 			       "%s: failed to claim resource %d\n",
267 			       dev_name(&pdev->dev), i);
268 			ret = -EBUSY;
269 			goto failed;
270 		}
271 	}
272 
273 	pr_debug("Registering platform device '%s'. Parent at %s\n",
274 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
275 
276 	ret = device_add(&pdev->dev);
277 	if (ret == 0)
278 		return ret;
279 
280  failed:
281 	while (--i >= 0) {
282 		struct resource *r = &pdev->resource[i];
283 		unsigned long type = resource_type(r);
284 
285 		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
286 			release_resource(r);
287 	}
288 
289 	return ret;
290 }
291 EXPORT_SYMBOL_GPL(platform_device_add);
292 
293 /**
294  * platform_device_del - remove a platform-level device
295  * @pdev: platform device we're removing
296  *
297  * Note that this function will also release all memory- and port-based
298  * resources owned by the device (@dev->resource).  This function must
299  * _only_ be externally called in error cases.  All other usage is a bug.
300  */
301 void platform_device_del(struct platform_device *pdev)
302 {
303 	int i;
304 
305 	if (pdev) {
306 		device_del(&pdev->dev);
307 
308 		for (i = 0; i < pdev->num_resources; i++) {
309 			struct resource *r = &pdev->resource[i];
310 			unsigned long type = resource_type(r);
311 
312 			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
313 				release_resource(r);
314 		}
315 	}
316 }
317 EXPORT_SYMBOL_GPL(platform_device_del);
318 
319 /**
320  * platform_device_register - add a platform-level device
321  * @pdev: platform device we're adding
322  */
323 int platform_device_register(struct platform_device *pdev)
324 {
325 	device_initialize(&pdev->dev);
326 	return platform_device_add(pdev);
327 }
328 EXPORT_SYMBOL_GPL(platform_device_register);
329 
330 /**
331  * platform_device_unregister - unregister a platform-level device
332  * @pdev: platform device we're unregistering
333  *
334  * Unregistration is done in 2 steps. First we release all resources
335  * and remove it from the subsystem, then we drop reference count by
336  * calling platform_device_put().
337  */
338 void platform_device_unregister(struct platform_device *pdev)
339 {
340 	platform_device_del(pdev);
341 	platform_device_put(pdev);
342 }
343 EXPORT_SYMBOL_GPL(platform_device_unregister);
344 
345 /**
346  * platform_device_register_simple
347  * @name: base name of the device we're adding
348  * @id: instance id
349  * @res: set of resources that needs to be allocated for the device
350  * @num: number of resources
351  *
352  * This function creates a simple platform device that requires minimal
353  * resource and memory management. Canned release function freeing memory
354  * allocated for the device allows drivers using such devices to be
355  * unloaded without waiting for the last reference to the device to be
356  * dropped.
357  *
358  * This interface is primarily intended for use with legacy drivers which
359  * probe hardware directly.  Because such drivers create sysfs device nodes
360  * themselves, rather than letting system infrastructure handle such device
361  * enumeration tasks, they don't fully conform to the Linux driver model.
362  * In particular, when such drivers are built as modules, they can't be
363  * "hotplugged".
364  */
365 struct platform_device *platform_device_register_simple(const char *name,
366 							int id,
367 							struct resource *res,
368 							unsigned int num)
369 {
370 	struct platform_device *pdev;
371 	int retval;
372 
373 	pdev = platform_device_alloc(name, id);
374 	if (!pdev) {
375 		retval = -ENOMEM;
376 		goto error;
377 	}
378 
379 	if (num) {
380 		retval = platform_device_add_resources(pdev, res, num);
381 		if (retval)
382 			goto error;
383 	}
384 
385 	retval = platform_device_add(pdev);
386 	if (retval)
387 		goto error;
388 
389 	return pdev;
390 
391 error:
392 	platform_device_put(pdev);
393 	return ERR_PTR(retval);
394 }
395 EXPORT_SYMBOL_GPL(platform_device_register_simple);
396 
397 /**
398  * platform_device_register_data
399  * @parent: parent device for the device we're adding
400  * @name: base name of the device we're adding
401  * @id: instance id
402  * @data: platform specific data for this platform device
403  * @size: size of platform specific data
404  *
405  * This function creates a simple platform device that requires minimal
406  * resource and memory management. Canned release function freeing memory
407  * allocated for the device allows drivers using such devices to be
408  * unloaded without waiting for the last reference to the device to be
409  * dropped.
410  */
411 struct platform_device *platform_device_register_data(
412 		struct device *parent,
413 		const char *name, int id,
414 		const void *data, size_t size)
415 {
416 	struct platform_device *pdev;
417 	int retval;
418 
419 	pdev = platform_device_alloc(name, id);
420 	if (!pdev) {
421 		retval = -ENOMEM;
422 		goto error;
423 	}
424 
425 	pdev->dev.parent = parent;
426 
427 	if (size) {
428 		retval = platform_device_add_data(pdev, data, size);
429 		if (retval)
430 			goto error;
431 	}
432 
433 	retval = platform_device_add(pdev);
434 	if (retval)
435 		goto error;
436 
437 	return pdev;
438 
439 error:
440 	platform_device_put(pdev);
441 	return ERR_PTR(retval);
442 }
443 
444 static int platform_drv_probe(struct device *_dev)
445 {
446 	struct platform_driver *drv = to_platform_driver(_dev->driver);
447 	struct platform_device *dev = to_platform_device(_dev);
448 
449 	return drv->probe(dev);
450 }
451 
452 static int platform_drv_probe_fail(struct device *_dev)
453 {
454 	return -ENXIO;
455 }
456 
457 static int platform_drv_remove(struct device *_dev)
458 {
459 	struct platform_driver *drv = to_platform_driver(_dev->driver);
460 	struct platform_device *dev = to_platform_device(_dev);
461 
462 	return drv->remove(dev);
463 }
464 
465 static void platform_drv_shutdown(struct device *_dev)
466 {
467 	struct platform_driver *drv = to_platform_driver(_dev->driver);
468 	struct platform_device *dev = to_platform_device(_dev);
469 
470 	drv->shutdown(dev);
471 }
472 
473 /**
474  * platform_driver_register
475  * @drv: platform driver structure
476  */
477 int platform_driver_register(struct platform_driver *drv)
478 {
479 	drv->driver.bus = &platform_bus_type;
480 	if (drv->probe)
481 		drv->driver.probe = platform_drv_probe;
482 	if (drv->remove)
483 		drv->driver.remove = platform_drv_remove;
484 	if (drv->shutdown)
485 		drv->driver.shutdown = platform_drv_shutdown;
486 	if (drv->suspend || drv->resume)
487 		pr_warning("Platform driver '%s' needs updating - please use "
488 			"dev_pm_ops\n", drv->driver.name);
489 
490 	return driver_register(&drv->driver);
491 }
492 EXPORT_SYMBOL_GPL(platform_driver_register);
493 
494 /**
495  * platform_driver_unregister
496  * @drv: platform driver structure
497  */
498 void platform_driver_unregister(struct platform_driver *drv)
499 {
500 	driver_unregister(&drv->driver);
501 }
502 EXPORT_SYMBOL_GPL(platform_driver_unregister);
503 
504 /**
505  * platform_driver_probe - register driver for non-hotpluggable device
506  * @drv: platform driver structure
507  * @probe: the driver probe routine, probably from an __init section
508  *
509  * Use this instead of platform_driver_register() when you know the device
510  * is not hotpluggable and has already been registered, and you want to
511  * remove its run-once probe() infrastructure from memory after the driver
512  * has bound to the device.
513  *
514  * One typical use for this would be with drivers for controllers integrated
515  * into system-on-chip processors, where the controller devices have been
516  * configured as part of board setup.
517  *
518  * Returns zero if the driver registered and bound to a device, else returns
519  * a negative error code and with the driver not registered.
520  */
521 int __init_or_module platform_driver_probe(struct platform_driver *drv,
522 		int (*probe)(struct platform_device *))
523 {
524 	int retval, code;
525 
526 	/* temporary section violation during probe() */
527 	drv->probe = probe;
528 	retval = code = platform_driver_register(drv);
529 
530 	/* Fixup that section violation, being paranoid about code scanning
531 	 * the list of drivers in order to probe new devices.  Check to see
532 	 * if the probe was successful, and make sure any forced probes of
533 	 * new devices fail.
534 	 */
535 	spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
536 	drv->probe = NULL;
537 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
538 		retval = -ENODEV;
539 	drv->driver.probe = platform_drv_probe_fail;
540 	spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);
541 
542 	if (code != retval)
543 		platform_driver_unregister(drv);
544 	return retval;
545 }
546 EXPORT_SYMBOL_GPL(platform_driver_probe);
547 
548 /* modalias support enables more hands-off userspace setup:
549  * (a) environment variable lets new-style hotplug events work once system is
550  *     fully running:  "modprobe $MODALIAS"
551  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
552  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
553  */
554 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
555 			     char *buf)
556 {
557 	struct platform_device	*pdev = to_platform_device(dev);
558 	int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
559 
560 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
561 }
562 
563 static struct device_attribute platform_dev_attrs[] = {
564 	__ATTR_RO(modalias),
565 	__ATTR_NULL,
566 };
567 
568 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
569 {
570 	struct platform_device	*pdev = to_platform_device(dev);
571 
572 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
573 		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);
574 	return 0;
575 }
576 
577 static const struct platform_device_id *platform_match_id(
578 			struct platform_device_id *id,
579 			struct platform_device *pdev)
580 {
581 	while (id->name[0]) {
582 		if (strcmp(pdev->name, id->name) == 0) {
583 			pdev->id_entry = id;
584 			return id;
585 		}
586 		id++;
587 	}
588 	return NULL;
589 }
590 
591 /**
592  * platform_match - bind platform device to platform driver.
593  * @dev: device.
594  * @drv: driver.
595  *
596  * Platform device IDs are assumed to be encoded like this:
597  * "<name><instance>", where <name> is a short description of the type of
598  * device, like "pci" or "floppy", and <instance> is the enumerated
599  * instance of the device, like '0' or '42'.  Driver IDs are simply
600  * "<name>".  So, extract the <name> from the platform_device structure,
601  * and compare it against the name of the driver. Return whether they match
602  * or not.
603  */
604 static int platform_match(struct device *dev, struct device_driver *drv)
605 {
606 	struct platform_device *pdev = to_platform_device(dev);
607 	struct platform_driver *pdrv = to_platform_driver(drv);
608 
609 	/* match against the id table first */
610 	if (pdrv->id_table)
611 		return platform_match_id(pdrv->id_table, pdev) != NULL;
612 
613 	/* fall-back to driver name match */
614 	return (strcmp(pdev->name, drv->name) == 0);
615 }
616 
617 #ifdef CONFIG_PM_SLEEP
618 
619 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
620 {
621 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
622 	struct platform_device *pdev = to_platform_device(dev);
623 	int ret = 0;
624 
625 	if (dev->driver && pdrv->suspend)
626 		ret = pdrv->suspend(pdev, mesg);
627 
628 	return ret;
629 }
630 
631 static int platform_legacy_suspend_late(struct device *dev, pm_message_t mesg)
632 {
633 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
634 	struct platform_device *pdev = to_platform_device(dev);
635 	int ret = 0;
636 
637 	if (dev->driver && pdrv->suspend_late)
638 		ret = pdrv->suspend_late(pdev, mesg);
639 
640 	return ret;
641 }
642 
643 static int platform_legacy_resume_early(struct device *dev)
644 {
645 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
646 	struct platform_device *pdev = to_platform_device(dev);
647 	int ret = 0;
648 
649 	if (dev->driver && pdrv->resume_early)
650 		ret = pdrv->resume_early(pdev);
651 
652 	return ret;
653 }
654 
655 static int platform_legacy_resume(struct device *dev)
656 {
657 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
658 	struct platform_device *pdev = to_platform_device(dev);
659 	int ret = 0;
660 
661 	if (dev->driver && pdrv->resume)
662 		ret = pdrv->resume(pdev);
663 
664 	return ret;
665 }
666 
667 static int platform_pm_prepare(struct device *dev)
668 {
669 	struct device_driver *drv = dev->driver;
670 	int ret = 0;
671 
672 	if (drv && drv->pm && drv->pm->prepare)
673 		ret = drv->pm->prepare(dev);
674 
675 	return ret;
676 }
677 
678 static void platform_pm_complete(struct device *dev)
679 {
680 	struct device_driver *drv = dev->driver;
681 
682 	if (drv && drv->pm && drv->pm->complete)
683 		drv->pm->complete(dev);
684 }
685 
686 #ifdef CONFIG_SUSPEND
687 
688 static int platform_pm_suspend(struct device *dev)
689 {
690 	struct device_driver *drv = dev->driver;
691 	int ret = 0;
692 
693 	if (!drv)
694 		return 0;
695 
696 	if (drv->pm) {
697 		if (drv->pm->suspend)
698 			ret = drv->pm->suspend(dev);
699 	} else {
700 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
701 	}
702 
703 	return ret;
704 }
705 
706 static int platform_pm_suspend_noirq(struct device *dev)
707 {
708 	struct device_driver *drv = dev->driver;
709 	int ret = 0;
710 
711 	if (!drv)
712 		return 0;
713 
714 	if (drv->pm) {
715 		if (drv->pm->suspend_noirq)
716 			ret = drv->pm->suspend_noirq(dev);
717 	} else {
718 		ret = platform_legacy_suspend_late(dev, PMSG_SUSPEND);
719 	}
720 
721 	return ret;
722 }
723 
724 static int platform_pm_resume(struct device *dev)
725 {
726 	struct device_driver *drv = dev->driver;
727 	int ret = 0;
728 
729 	if (!drv)
730 		return 0;
731 
732 	if (drv->pm) {
733 		if (drv->pm->resume)
734 			ret = drv->pm->resume(dev);
735 	} else {
736 		ret = platform_legacy_resume(dev);
737 	}
738 
739 	return ret;
740 }
741 
742 static int platform_pm_resume_noirq(struct device *dev)
743 {
744 	struct device_driver *drv = dev->driver;
745 	int ret = 0;
746 
747 	if (!drv)
748 		return 0;
749 
750 	if (drv->pm) {
751 		if (drv->pm->resume_noirq)
752 			ret = drv->pm->resume_noirq(dev);
753 	} else {
754 		ret = platform_legacy_resume_early(dev);
755 	}
756 
757 	return ret;
758 }
759 
760 #else /* !CONFIG_SUSPEND */
761 
762 #define platform_pm_suspend		NULL
763 #define platform_pm_resume		NULL
764 #define platform_pm_suspend_noirq	NULL
765 #define platform_pm_resume_noirq	NULL
766 
767 #endif /* !CONFIG_SUSPEND */
768 
769 #ifdef CONFIG_HIBERNATION
770 
771 static int platform_pm_freeze(struct device *dev)
772 {
773 	struct device_driver *drv = dev->driver;
774 	int ret = 0;
775 
776 	if (!drv)
777 		return 0;
778 
779 	if (drv->pm) {
780 		if (drv->pm->freeze)
781 			ret = drv->pm->freeze(dev);
782 	} else {
783 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
784 	}
785 
786 	return ret;
787 }
788 
789 static int platform_pm_freeze_noirq(struct device *dev)
790 {
791 	struct device_driver *drv = dev->driver;
792 	int ret = 0;
793 
794 	if (!drv)
795 		return 0;
796 
797 	if (drv->pm) {
798 		if (drv->pm->freeze_noirq)
799 			ret = drv->pm->freeze_noirq(dev);
800 	} else {
801 		ret = platform_legacy_suspend_late(dev, PMSG_FREEZE);
802 	}
803 
804 	return ret;
805 }
806 
807 static int platform_pm_thaw(struct device *dev)
808 {
809 	struct device_driver *drv = dev->driver;
810 	int ret = 0;
811 
812 	if (!drv)
813 		return 0;
814 
815 	if (drv->pm) {
816 		if (drv->pm->thaw)
817 			ret = drv->pm->thaw(dev);
818 	} else {
819 		ret = platform_legacy_resume(dev);
820 	}
821 
822 	return ret;
823 }
824 
825 static int platform_pm_thaw_noirq(struct device *dev)
826 {
827 	struct device_driver *drv = dev->driver;
828 	int ret = 0;
829 
830 	if (!drv)
831 		return 0;
832 
833 	if (drv->pm) {
834 		if (drv->pm->thaw_noirq)
835 			ret = drv->pm->thaw_noirq(dev);
836 	} else {
837 		ret = platform_legacy_resume_early(dev);
838 	}
839 
840 	return ret;
841 }
842 
843 static int platform_pm_poweroff(struct device *dev)
844 {
845 	struct device_driver *drv = dev->driver;
846 	int ret = 0;
847 
848 	if (!drv)
849 		return 0;
850 
851 	if (drv->pm) {
852 		if (drv->pm->poweroff)
853 			ret = drv->pm->poweroff(dev);
854 	} else {
855 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
856 	}
857 
858 	return ret;
859 }
860 
861 static int platform_pm_poweroff_noirq(struct device *dev)
862 {
863 	struct device_driver *drv = dev->driver;
864 	int ret = 0;
865 
866 	if (!drv)
867 		return 0;
868 
869 	if (drv->pm) {
870 		if (drv->pm->poweroff_noirq)
871 			ret = drv->pm->poweroff_noirq(dev);
872 	} else {
873 		ret = platform_legacy_suspend_late(dev, PMSG_HIBERNATE);
874 	}
875 
876 	return ret;
877 }
878 
879 static int platform_pm_restore(struct device *dev)
880 {
881 	struct device_driver *drv = dev->driver;
882 	int ret = 0;
883 
884 	if (!drv)
885 		return 0;
886 
887 	if (drv->pm) {
888 		if (drv->pm->restore)
889 			ret = drv->pm->restore(dev);
890 	} else {
891 		ret = platform_legacy_resume(dev);
892 	}
893 
894 	return ret;
895 }
896 
897 static int platform_pm_restore_noirq(struct device *dev)
898 {
899 	struct device_driver *drv = dev->driver;
900 	int ret = 0;
901 
902 	if (!drv)
903 		return 0;
904 
905 	if (drv->pm) {
906 		if (drv->pm->restore_noirq)
907 			ret = drv->pm->restore_noirq(dev);
908 	} else {
909 		ret = platform_legacy_resume_early(dev);
910 	}
911 
912 	return ret;
913 }
914 
915 #else /* !CONFIG_HIBERNATION */
916 
917 #define platform_pm_freeze		NULL
918 #define platform_pm_thaw		NULL
919 #define platform_pm_poweroff		NULL
920 #define platform_pm_restore		NULL
921 #define platform_pm_freeze_noirq	NULL
922 #define platform_pm_thaw_noirq		NULL
923 #define platform_pm_poweroff_noirq	NULL
924 #define platform_pm_restore_noirq	NULL
925 
926 #endif /* !CONFIG_HIBERNATION */
927 
928 static struct dev_pm_ops platform_dev_pm_ops = {
929 	.prepare = platform_pm_prepare,
930 	.complete = platform_pm_complete,
931 	.suspend = platform_pm_suspend,
932 	.resume = platform_pm_resume,
933 	.freeze = platform_pm_freeze,
934 	.thaw = platform_pm_thaw,
935 	.poweroff = platform_pm_poweroff,
936 	.restore = platform_pm_restore,
937 	.suspend_noirq = platform_pm_suspend_noirq,
938 	.resume_noirq = platform_pm_resume_noirq,
939 	.freeze_noirq = platform_pm_freeze_noirq,
940 	.thaw_noirq = platform_pm_thaw_noirq,
941 	.poweroff_noirq = platform_pm_poweroff_noirq,
942 	.restore_noirq = platform_pm_restore_noirq,
943 };
944 
945 #define PLATFORM_PM_OPS_PTR	(&platform_dev_pm_ops)
946 
947 #else /* !CONFIG_PM_SLEEP */
948 
949 #define PLATFORM_PM_OPS_PTR	NULL
950 
951 #endif /* !CONFIG_PM_SLEEP */
952 
953 struct bus_type platform_bus_type = {
954 	.name		= "platform",
955 	.dev_attrs	= platform_dev_attrs,
956 	.match		= platform_match,
957 	.uevent		= platform_uevent,
958 	.pm		= PLATFORM_PM_OPS_PTR,
959 };
960 EXPORT_SYMBOL_GPL(platform_bus_type);
961 
962 int __init platform_bus_init(void)
963 {
964 	int error;
965 
966 	early_platform_cleanup();
967 
968 	error = device_register(&platform_bus);
969 	if (error)
970 		return error;
971 	error =  bus_register(&platform_bus_type);
972 	if (error)
973 		device_unregister(&platform_bus);
974 	return error;
975 }
976 
977 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
978 u64 dma_get_required_mask(struct device *dev)
979 {
980 	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
981 	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
982 	u64 mask;
983 
984 	if (!high_totalram) {
985 		/* convert to mask just covering totalram */
986 		low_totalram = (1 << (fls(low_totalram) - 1));
987 		low_totalram += low_totalram - 1;
988 		mask = low_totalram;
989 	} else {
990 		high_totalram = (1 << (fls(high_totalram) - 1));
991 		high_totalram += high_totalram - 1;
992 		mask = (((u64)high_totalram) << 32) + 0xffffffff;
993 	}
994 	return mask;
995 }
996 EXPORT_SYMBOL_GPL(dma_get_required_mask);
997 #endif
998 
999 static __initdata LIST_HEAD(early_platform_driver_list);
1000 static __initdata LIST_HEAD(early_platform_device_list);
1001 
1002 /**
1003  * early_platform_driver_register
1004  * @epdrv: early_platform driver structure
1005  * @buf: string passed from early_param()
1006  */
1007 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1008 					  char *buf)
1009 {
1010 	unsigned long index;
1011 	int n;
1012 
1013 	/* Simply add the driver to the end of the global list.
1014 	 * Drivers will by default be put on the list in compiled-in order.
1015 	 */
1016 	if (!epdrv->list.next) {
1017 		INIT_LIST_HEAD(&epdrv->list);
1018 		list_add_tail(&epdrv->list, &early_platform_driver_list);
1019 	}
1020 
1021 	/* If the user has specified device then make sure the driver
1022 	 * gets prioritized. The driver of the last device specified on
1023 	 * command line will be put first on the list.
1024 	 */
1025 	n = strlen(epdrv->pdrv->driver.name);
1026 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1027 		list_move(&epdrv->list, &early_platform_driver_list);
1028 
1029 		if (!strcmp(buf, epdrv->pdrv->driver.name))
1030 			epdrv->requested_id = -1;
1031 		else if (buf[n] == '.' && strict_strtoul(&buf[n + 1], 10,
1032 							 &index) == 0)
1033 			epdrv->requested_id = index;
1034 		else
1035 			epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1036 	}
1037 
1038 	return 0;
1039 }
1040 
1041 /**
1042  * early_platform_add_devices - add a numbers of early platform devices
1043  * @devs: array of early platform devices to add
1044  * @num: number of early platform devices in array
1045  */
1046 void __init early_platform_add_devices(struct platform_device **devs, int num)
1047 {
1048 	struct device *dev;
1049 	int i;
1050 
1051 	/* simply add the devices to list */
1052 	for (i = 0; i < num; i++) {
1053 		dev = &devs[i]->dev;
1054 
1055 		if (!dev->devres_head.next) {
1056 			INIT_LIST_HEAD(&dev->devres_head);
1057 			list_add_tail(&dev->devres_head,
1058 				      &early_platform_device_list);
1059 		}
1060 	}
1061 }
1062 
1063 /**
1064  * early_platform_driver_register_all
1065  * @class_str: string to identify early platform driver class
1066  */
1067 void __init early_platform_driver_register_all(char *class_str)
1068 {
1069 	/* The "class_str" parameter may or may not be present on the kernel
1070 	 * command line. If it is present then there may be more than one
1071 	 * matching parameter.
1072 	 *
1073 	 * Since we register our early platform drivers using early_param()
1074 	 * we need to make sure that they also get registered in the case
1075 	 * when the parameter is missing from the kernel command line.
1076 	 *
1077 	 * We use parse_early_options() to make sure the early_param() gets
1078 	 * called at least once. The early_param() may be called more than
1079 	 * once since the name of the preferred device may be specified on
1080 	 * the kernel command line. early_platform_driver_register() handles
1081 	 * this case for us.
1082 	 */
1083 	parse_early_options(class_str);
1084 }
1085 
1086 /**
1087  * early_platform_match
1088  * @epdrv: early platform driver structure
1089  * @id: id to match against
1090  */
1091 static  __init struct platform_device *
1092 early_platform_match(struct early_platform_driver *epdrv, int id)
1093 {
1094 	struct platform_device *pd;
1095 
1096 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1097 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1098 			if (pd->id == id)
1099 				return pd;
1100 
1101 	return NULL;
1102 }
1103 
1104 /**
1105  * early_platform_left
1106  * @epdrv: early platform driver structure
1107  * @id: return true if id or above exists
1108  */
1109 static  __init int early_platform_left(struct early_platform_driver *epdrv,
1110 				       int id)
1111 {
1112 	struct platform_device *pd;
1113 
1114 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1115 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1116 			if (pd->id >= id)
1117 				return 1;
1118 
1119 	return 0;
1120 }
1121 
1122 /**
1123  * early_platform_driver_probe_id
1124  * @class_str: string to identify early platform driver class
1125  * @id: id to match against
1126  * @nr_probe: number of platform devices to successfully probe before exiting
1127  */
1128 static int __init early_platform_driver_probe_id(char *class_str,
1129 						 int id,
1130 						 int nr_probe)
1131 {
1132 	struct early_platform_driver *epdrv;
1133 	struct platform_device *match;
1134 	int match_id;
1135 	int n = 0;
1136 	int left = 0;
1137 
1138 	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1139 		/* only use drivers matching our class_str */
1140 		if (strcmp(class_str, epdrv->class_str))
1141 			continue;
1142 
1143 		if (id == -2) {
1144 			match_id = epdrv->requested_id;
1145 			left = 1;
1146 
1147 		} else {
1148 			match_id = id;
1149 			left += early_platform_left(epdrv, id);
1150 
1151 			/* skip requested id */
1152 			switch (epdrv->requested_id) {
1153 			case EARLY_PLATFORM_ID_ERROR:
1154 			case EARLY_PLATFORM_ID_UNSET:
1155 				break;
1156 			default:
1157 				if (epdrv->requested_id == id)
1158 					match_id = EARLY_PLATFORM_ID_UNSET;
1159 			}
1160 		}
1161 
1162 		switch (match_id) {
1163 		case EARLY_PLATFORM_ID_ERROR:
1164 			pr_warning("%s: unable to parse %s parameter\n",
1165 				   class_str, epdrv->pdrv->driver.name);
1166 			/* fall-through */
1167 		case EARLY_PLATFORM_ID_UNSET:
1168 			match = NULL;
1169 			break;
1170 		default:
1171 			match = early_platform_match(epdrv, match_id);
1172 		}
1173 
1174 		if (match) {
1175 			if (epdrv->pdrv->probe(match))
1176 				pr_warning("%s: unable to probe %s early.\n",
1177 					   class_str, match->name);
1178 			else
1179 				n++;
1180 		}
1181 
1182 		if (n >= nr_probe)
1183 			break;
1184 	}
1185 
1186 	if (left)
1187 		return n;
1188 	else
1189 		return -ENODEV;
1190 }
1191 
1192 /**
1193  * early_platform_driver_probe
1194  * @class_str: string to identify early platform driver class
1195  * @nr_probe: number of platform devices to successfully probe before exiting
1196  * @user_only: only probe user specified early platform devices
1197  */
1198 int __init early_platform_driver_probe(char *class_str,
1199 				       int nr_probe,
1200 				       int user_only)
1201 {
1202 	int k, n, i;
1203 
1204 	n = 0;
1205 	for (i = -2; n < nr_probe; i++) {
1206 		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1207 
1208 		if (k < 0)
1209 			break;
1210 
1211 		n += k;
1212 
1213 		if (user_only)
1214 			break;
1215 	}
1216 
1217 	return n;
1218 }
1219 
1220 /**
1221  * early_platform_cleanup - clean up early platform code
1222  */
1223 void __init early_platform_cleanup(void)
1224 {
1225 	struct platform_device *pd, *pd2;
1226 
1227 	/* clean up the devres list used to chain devices */
1228 	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1229 				 dev.devres_head) {
1230 		list_del(&pd->dev.devres_head);
1231 		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1232 	}
1233 }
1234 
1235