xref: /linux/drivers/base/platform.c (revision e27ecdd94d81e5bc3d1f68591701db5adb342f0d)
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, char *name)
73 {
74 	int i;
75 
76 	for (i = 0; i < dev->num_resources; i++) {
77 		struct resource *r = &dev->resource[i];
78 
79 		if (type == resource_type(r) && !strcmp(r->name, name))
80 			return r;
81 	}
82 	return NULL;
83 }
84 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
85 
86 /**
87  * platform_get_irq - get an IRQ for a device
88  * @dev: platform device
89  * @name: IRQ name
90  */
91 int platform_get_irq_byname(struct platform_device *dev, char *name)
92 {
93 	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
94 							  name);
95 
96 	return r ? r->start : -ENXIO;
97 }
98 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
99 
100 /**
101  * platform_add_devices - add a numbers of platform devices
102  * @devs: array of platform devices to add
103  * @num: number of platform devices in array
104  */
105 int platform_add_devices(struct platform_device **devs, int num)
106 {
107 	int i, ret = 0;
108 
109 	for (i = 0; i < num; i++) {
110 		ret = platform_device_register(devs[i]);
111 		if (ret) {
112 			while (--i >= 0)
113 				platform_device_unregister(devs[i]);
114 			break;
115 		}
116 	}
117 
118 	return ret;
119 }
120 EXPORT_SYMBOL_GPL(platform_add_devices);
121 
122 struct platform_object {
123 	struct platform_device pdev;
124 	char name[1];
125 };
126 
127 /**
128  * platform_device_put
129  * @pdev: platform device to free
130  *
131  * Free all memory associated with a platform device.  This function must
132  * _only_ be externally called in error cases.  All other usage is a bug.
133  */
134 void platform_device_put(struct platform_device *pdev)
135 {
136 	if (pdev)
137 		put_device(&pdev->dev);
138 }
139 EXPORT_SYMBOL_GPL(platform_device_put);
140 
141 static void platform_device_release(struct device *dev)
142 {
143 	struct platform_object *pa = container_of(dev, struct platform_object,
144 						  pdev.dev);
145 
146 	kfree(pa->pdev.dev.platform_data);
147 	kfree(pa->pdev.resource);
148 	kfree(pa);
149 }
150 
151 /**
152  * platform_device_alloc
153  * @name: base name of the device we're adding
154  * @id: instance id
155  *
156  * Create a platform device object which can have other objects attached
157  * to it, and which will have attached objects freed when it is released.
158  */
159 struct platform_device *platform_device_alloc(const char *name, int id)
160 {
161 	struct platform_object *pa;
162 
163 	pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
164 	if (pa) {
165 		strcpy(pa->name, name);
166 		pa->pdev.name = pa->name;
167 		pa->pdev.id = id;
168 		device_initialize(&pa->pdev.dev);
169 		pa->pdev.dev.release = platform_device_release;
170 	}
171 
172 	return pa ? &pa->pdev : NULL;
173 }
174 EXPORT_SYMBOL_GPL(platform_device_alloc);
175 
176 /**
177  * platform_device_add_resources
178  * @pdev: platform device allocated by platform_device_alloc to add resources to
179  * @res: set of resources that needs to be allocated for the device
180  * @num: number of resources
181  *
182  * Add a copy of the resources to the platform device.  The memory
183  * associated with the resources will be freed when the platform device is
184  * released.
185  */
186 int platform_device_add_resources(struct platform_device *pdev,
187 				  struct resource *res, unsigned int num)
188 {
189 	struct resource *r;
190 
191 	r = kmalloc(sizeof(struct resource) * num, GFP_KERNEL);
192 	if (r) {
193 		memcpy(r, res, sizeof(struct resource) * num);
194 		pdev->resource = r;
195 		pdev->num_resources = num;
196 	}
197 	return r ? 0 : -ENOMEM;
198 }
199 EXPORT_SYMBOL_GPL(platform_device_add_resources);
200 
201 /**
202  * platform_device_add_data
203  * @pdev: platform device allocated by platform_device_alloc to add resources to
204  * @data: platform specific data for this platform device
205  * @size: size of platform specific data
206  *
207  * Add a copy of platform specific data to the platform device's
208  * platform_data pointer.  The memory associated with the platform data
209  * will be freed when the platform device is released.
210  */
211 int platform_device_add_data(struct platform_device *pdev, const void *data,
212 			     size_t size)
213 {
214 	void *d;
215 
216 	d = kmalloc(size, GFP_KERNEL);
217 	if (d) {
218 		memcpy(d, data, size);
219 		pdev->dev.platform_data = d;
220 	}
221 	return d ? 0 : -ENOMEM;
222 }
223 EXPORT_SYMBOL_GPL(platform_device_add_data);
224 
225 /**
226  * platform_device_add - add a platform device to device hierarchy
227  * @pdev: platform device we're adding
228  *
229  * This is part 2 of platform_device_register(), though may be called
230  * separately _iff_ pdev was allocated by platform_device_alloc().
231  */
232 int platform_device_add(struct platform_device *pdev)
233 {
234 	int i, ret = 0;
235 
236 	if (!pdev)
237 		return -EINVAL;
238 
239 	if (!pdev->dev.parent)
240 		pdev->dev.parent = &platform_bus;
241 
242 	pdev->dev.bus = &platform_bus_type;
243 
244 	if (pdev->id != -1)
245 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
246 	else
247 		dev_set_name(&pdev->dev, pdev->name);
248 
249 	for (i = 0; i < pdev->num_resources; i++) {
250 		struct resource *p, *r = &pdev->resource[i];
251 
252 		if (r->name == NULL)
253 			r->name = dev_name(&pdev->dev);
254 
255 		p = r->parent;
256 		if (!p) {
257 			if (resource_type(r) == IORESOURCE_MEM)
258 				p = &iomem_resource;
259 			else if (resource_type(r) == IORESOURCE_IO)
260 				p = &ioport_resource;
261 		}
262 
263 		if (p && insert_resource(p, r)) {
264 			printk(KERN_ERR
265 			       "%s: failed to claim resource %d\n",
266 			       dev_name(&pdev->dev), i);
267 			ret = -EBUSY;
268 			goto failed;
269 		}
270 	}
271 
272 	pr_debug("Registering platform device '%s'. Parent at %s\n",
273 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
274 
275 	ret = device_add(&pdev->dev);
276 	if (ret == 0)
277 		return ret;
278 
279  failed:
280 	while (--i >= 0) {
281 		struct resource *r = &pdev->resource[i];
282 		unsigned long type = resource_type(r);
283 
284 		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
285 			release_resource(r);
286 	}
287 
288 	return ret;
289 }
290 EXPORT_SYMBOL_GPL(platform_device_add);
291 
292 /**
293  * platform_device_del - remove a platform-level device
294  * @pdev: platform device we're removing
295  *
296  * Note that this function will also release all memory- and port-based
297  * resources owned by the device (@dev->resource).  This function must
298  * _only_ be externally called in error cases.  All other usage is a bug.
299  */
300 void platform_device_del(struct platform_device *pdev)
301 {
302 	int i;
303 
304 	if (pdev) {
305 		device_del(&pdev->dev);
306 
307 		for (i = 0; i < pdev->num_resources; i++) {
308 			struct resource *r = &pdev->resource[i];
309 			unsigned long type = resource_type(r);
310 
311 			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
312 				release_resource(r);
313 		}
314 	}
315 }
316 EXPORT_SYMBOL_GPL(platform_device_del);
317 
318 /**
319  * platform_device_register - add a platform-level device
320  * @pdev: platform device we're adding
321  */
322 int platform_device_register(struct platform_device *pdev)
323 {
324 	device_initialize(&pdev->dev);
325 	return platform_device_add(pdev);
326 }
327 EXPORT_SYMBOL_GPL(platform_device_register);
328 
329 /**
330  * platform_device_unregister - unregister a platform-level device
331  * @pdev: platform device we're unregistering
332  *
333  * Unregistration is done in 2 steps. First we release all resources
334  * and remove it from the subsystem, then we drop reference count by
335  * calling platform_device_put().
336  */
337 void platform_device_unregister(struct platform_device *pdev)
338 {
339 	platform_device_del(pdev);
340 	platform_device_put(pdev);
341 }
342 EXPORT_SYMBOL_GPL(platform_device_unregister);
343 
344 /**
345  * platform_device_register_simple
346  * @name: base name of the device we're adding
347  * @id: instance id
348  * @res: set of resources that needs to be allocated for the device
349  * @num: number of resources
350  *
351  * This function creates a simple platform device that requires minimal
352  * resource and memory management. Canned release function freeing memory
353  * allocated for the device allows drivers using such devices to be
354  * unloaded without waiting for the last reference to the device to be
355  * dropped.
356  *
357  * This interface is primarily intended for use with legacy drivers which
358  * probe hardware directly.  Because such drivers create sysfs device nodes
359  * themselves, rather than letting system infrastructure handle such device
360  * enumeration tasks, they don't fully conform to the Linux driver model.
361  * In particular, when such drivers are built as modules, they can't be
362  * "hotplugged".
363  */
364 struct platform_device *platform_device_register_simple(const char *name,
365 							int id,
366 							struct resource *res,
367 							unsigned int num)
368 {
369 	struct platform_device *pdev;
370 	int retval;
371 
372 	pdev = platform_device_alloc(name, id);
373 	if (!pdev) {
374 		retval = -ENOMEM;
375 		goto error;
376 	}
377 
378 	if (num) {
379 		retval = platform_device_add_resources(pdev, res, num);
380 		if (retval)
381 			goto error;
382 	}
383 
384 	retval = platform_device_add(pdev);
385 	if (retval)
386 		goto error;
387 
388 	return pdev;
389 
390 error:
391 	platform_device_put(pdev);
392 	return ERR_PTR(retval);
393 }
394 EXPORT_SYMBOL_GPL(platform_device_register_simple);
395 
396 /**
397  * platform_device_register_data
398  * @parent: parent device for the device we're adding
399  * @name: base name of the device we're adding
400  * @id: instance id
401  * @data: platform specific data for this platform device
402  * @size: size of platform specific data
403  *
404  * This function creates a simple platform device that requires minimal
405  * resource and memory management. Canned release function freeing memory
406  * allocated for the device allows drivers using such devices to be
407  * unloaded without waiting for the last reference to the device to be
408  * dropped.
409  */
410 struct platform_device *platform_device_register_data(
411 		struct device *parent,
412 		const char *name, int id,
413 		const void *data, size_t size)
414 {
415 	struct platform_device *pdev;
416 	int retval;
417 
418 	pdev = platform_device_alloc(name, id);
419 	if (!pdev) {
420 		retval = -ENOMEM;
421 		goto error;
422 	}
423 
424 	pdev->dev.parent = parent;
425 
426 	if (size) {
427 		retval = platform_device_add_data(pdev, data, size);
428 		if (retval)
429 			goto error;
430 	}
431 
432 	retval = platform_device_add(pdev);
433 	if (retval)
434 		goto error;
435 
436 	return pdev;
437 
438 error:
439 	platform_device_put(pdev);
440 	return ERR_PTR(retval);
441 }
442 
443 static int platform_drv_probe(struct device *_dev)
444 {
445 	struct platform_driver *drv = to_platform_driver(_dev->driver);
446 	struct platform_device *dev = to_platform_device(_dev);
447 
448 	return drv->probe(dev);
449 }
450 
451 static int platform_drv_probe_fail(struct device *_dev)
452 {
453 	return -ENXIO;
454 }
455 
456 static int platform_drv_remove(struct device *_dev)
457 {
458 	struct platform_driver *drv = to_platform_driver(_dev->driver);
459 	struct platform_device *dev = to_platform_device(_dev);
460 
461 	return drv->remove(dev);
462 }
463 
464 static void platform_drv_shutdown(struct device *_dev)
465 {
466 	struct platform_driver *drv = to_platform_driver(_dev->driver);
467 	struct platform_device *dev = to_platform_device(_dev);
468 
469 	drv->shutdown(dev);
470 }
471 
472 /**
473  * platform_driver_register
474  * @drv: platform driver structure
475  */
476 int platform_driver_register(struct platform_driver *drv)
477 {
478 	drv->driver.bus = &platform_bus_type;
479 	if (drv->probe)
480 		drv->driver.probe = platform_drv_probe;
481 	if (drv->remove)
482 		drv->driver.remove = platform_drv_remove;
483 	if (drv->shutdown)
484 		drv->driver.shutdown = platform_drv_shutdown;
485 	if (drv->suspend || drv->resume)
486 		pr_warning("Platform driver '%s' needs updating - please use "
487 			"dev_pm_ops\n", drv->driver.name);
488 
489 	return driver_register(&drv->driver);
490 }
491 EXPORT_SYMBOL_GPL(platform_driver_register);
492 
493 /**
494  * platform_driver_unregister
495  * @drv: platform driver structure
496  */
497 void platform_driver_unregister(struct platform_driver *drv)
498 {
499 	driver_unregister(&drv->driver);
500 }
501 EXPORT_SYMBOL_GPL(platform_driver_unregister);
502 
503 /**
504  * platform_driver_probe - register driver for non-hotpluggable device
505  * @drv: platform driver structure
506  * @probe: the driver probe routine, probably from an __init section
507  *
508  * Use this instead of platform_driver_register() when you know the device
509  * is not hotpluggable and has already been registered, and you want to
510  * remove its run-once probe() infrastructure from memory after the driver
511  * has bound to the device.
512  *
513  * One typical use for this would be with drivers for controllers integrated
514  * into system-on-chip processors, where the controller devices have been
515  * configured as part of board setup.
516  *
517  * Returns zero if the driver registered and bound to a device, else returns
518  * a negative error code and with the driver not registered.
519  */
520 int __init_or_module platform_driver_probe(struct platform_driver *drv,
521 		int (*probe)(struct platform_device *))
522 {
523 	int retval, code;
524 
525 	/* temporary section violation during probe() */
526 	drv->probe = probe;
527 	retval = code = platform_driver_register(drv);
528 
529 	/* Fixup that section violation, being paranoid about code scanning
530 	 * the list of drivers in order to probe new devices.  Check to see
531 	 * if the probe was successful, and make sure any forced probes of
532 	 * new devices fail.
533 	 */
534 	spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
535 	drv->probe = NULL;
536 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
537 		retval = -ENODEV;
538 	drv->driver.probe = platform_drv_probe_fail;
539 	spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);
540 
541 	if (code != retval)
542 		platform_driver_unregister(drv);
543 	return retval;
544 }
545 EXPORT_SYMBOL_GPL(platform_driver_probe);
546 
547 /* modalias support enables more hands-off userspace setup:
548  * (a) environment variable lets new-style hotplug events work once system is
549  *     fully running:  "modprobe $MODALIAS"
550  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
551  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
552  */
553 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
554 			     char *buf)
555 {
556 	struct platform_device	*pdev = to_platform_device(dev);
557 	int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
558 
559 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
560 }
561 
562 static struct device_attribute platform_dev_attrs[] = {
563 	__ATTR_RO(modalias),
564 	__ATTR_NULL,
565 };
566 
567 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
568 {
569 	struct platform_device	*pdev = to_platform_device(dev);
570 
571 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
572 		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);
573 	return 0;
574 }
575 
576 static const struct platform_device_id *platform_match_id(
577 			struct platform_device_id *id,
578 			struct platform_device *pdev)
579 {
580 	while (id->name[0]) {
581 		if (strcmp(pdev->name, id->name) == 0) {
582 			pdev->id_entry = id;
583 			return id;
584 		}
585 		id++;
586 	}
587 	return NULL;
588 }
589 
590 /**
591  * platform_match - bind platform device to platform driver.
592  * @dev: device.
593  * @drv: driver.
594  *
595  * Platform device IDs are assumed to be encoded like this:
596  * "<name><instance>", where <name> is a short description of the type of
597  * device, like "pci" or "floppy", and <instance> is the enumerated
598  * instance of the device, like '0' or '42'.  Driver IDs are simply
599  * "<name>".  So, extract the <name> from the platform_device structure,
600  * and compare it against the name of the driver. Return whether they match
601  * or not.
602  */
603 static int platform_match(struct device *dev, struct device_driver *drv)
604 {
605 	struct platform_device *pdev = to_platform_device(dev);
606 	struct platform_driver *pdrv = to_platform_driver(drv);
607 
608 	/* match against the id table first */
609 	if (pdrv->id_table)
610 		return platform_match_id(pdrv->id_table, pdev) != NULL;
611 
612 	/* fall-back to driver name match */
613 	return (strcmp(pdev->name, drv->name) == 0);
614 }
615 
616 #ifdef CONFIG_PM_SLEEP
617 
618 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
619 {
620 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
621 	struct platform_device *pdev = to_platform_device(dev);
622 	int ret = 0;
623 
624 	if (dev->driver && pdrv->suspend)
625 		ret = pdrv->suspend(pdev, mesg);
626 
627 	return ret;
628 }
629 
630 static int platform_legacy_suspend_late(struct device *dev, pm_message_t mesg)
631 {
632 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
633 	struct platform_device *pdev = to_platform_device(dev);
634 	int ret = 0;
635 
636 	if (dev->driver && pdrv->suspend_late)
637 		ret = pdrv->suspend_late(pdev, mesg);
638 
639 	return ret;
640 }
641 
642 static int platform_legacy_resume_early(struct device *dev)
643 {
644 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
645 	struct platform_device *pdev = to_platform_device(dev);
646 	int ret = 0;
647 
648 	if (dev->driver && pdrv->resume_early)
649 		ret = pdrv->resume_early(pdev);
650 
651 	return ret;
652 }
653 
654 static int platform_legacy_resume(struct device *dev)
655 {
656 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
657 	struct platform_device *pdev = to_platform_device(dev);
658 	int ret = 0;
659 
660 	if (dev->driver && pdrv->resume)
661 		ret = pdrv->resume(pdev);
662 
663 	return ret;
664 }
665 
666 static int platform_pm_prepare(struct device *dev)
667 {
668 	struct device_driver *drv = dev->driver;
669 	int ret = 0;
670 
671 	if (drv && drv->pm && drv->pm->prepare)
672 		ret = drv->pm->prepare(dev);
673 
674 	return ret;
675 }
676 
677 static void platform_pm_complete(struct device *dev)
678 {
679 	struct device_driver *drv = dev->driver;
680 
681 	if (drv && drv->pm && drv->pm->complete)
682 		drv->pm->complete(dev);
683 }
684 
685 #ifdef CONFIG_SUSPEND
686 
687 static int platform_pm_suspend(struct device *dev)
688 {
689 	struct device_driver *drv = dev->driver;
690 	int ret = 0;
691 
692 	if (!drv)
693 		return 0;
694 
695 	if (drv->pm) {
696 		if (drv->pm->suspend)
697 			ret = drv->pm->suspend(dev);
698 	} else {
699 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
700 	}
701 
702 	return ret;
703 }
704 
705 static int platform_pm_suspend_noirq(struct device *dev)
706 {
707 	struct device_driver *drv = dev->driver;
708 	int ret = 0;
709 
710 	if (!drv)
711 		return 0;
712 
713 	if (drv->pm) {
714 		if (drv->pm->suspend_noirq)
715 			ret = drv->pm->suspend_noirq(dev);
716 	} else {
717 		ret = platform_legacy_suspend_late(dev, PMSG_SUSPEND);
718 	}
719 
720 	return ret;
721 }
722 
723 static int platform_pm_resume(struct device *dev)
724 {
725 	struct device_driver *drv = dev->driver;
726 	int ret = 0;
727 
728 	if (!drv)
729 		return 0;
730 
731 	if (drv->pm) {
732 		if (drv->pm->resume)
733 			ret = drv->pm->resume(dev);
734 	} else {
735 		ret = platform_legacy_resume(dev);
736 	}
737 
738 	return ret;
739 }
740 
741 static int platform_pm_resume_noirq(struct device *dev)
742 {
743 	struct device_driver *drv = dev->driver;
744 	int ret = 0;
745 
746 	if (!drv)
747 		return 0;
748 
749 	if (drv->pm) {
750 		if (drv->pm->resume_noirq)
751 			ret = drv->pm->resume_noirq(dev);
752 	} else {
753 		ret = platform_legacy_resume_early(dev);
754 	}
755 
756 	return ret;
757 }
758 
759 #else /* !CONFIG_SUSPEND */
760 
761 #define platform_pm_suspend		NULL
762 #define platform_pm_resume		NULL
763 #define platform_pm_suspend_noirq	NULL
764 #define platform_pm_resume_noirq	NULL
765 
766 #endif /* !CONFIG_SUSPEND */
767 
768 #ifdef CONFIG_HIBERNATION
769 
770 static int platform_pm_freeze(struct device *dev)
771 {
772 	struct device_driver *drv = dev->driver;
773 	int ret = 0;
774 
775 	if (!drv)
776 		return 0;
777 
778 	if (drv->pm) {
779 		if (drv->pm->freeze)
780 			ret = drv->pm->freeze(dev);
781 	} else {
782 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
783 	}
784 
785 	return ret;
786 }
787 
788 static int platform_pm_freeze_noirq(struct device *dev)
789 {
790 	struct device_driver *drv = dev->driver;
791 	int ret = 0;
792 
793 	if (!drv)
794 		return 0;
795 
796 	if (drv->pm) {
797 		if (drv->pm->freeze_noirq)
798 			ret = drv->pm->freeze_noirq(dev);
799 	} else {
800 		ret = platform_legacy_suspend_late(dev, PMSG_FREEZE);
801 	}
802 
803 	return ret;
804 }
805 
806 static int platform_pm_thaw(struct device *dev)
807 {
808 	struct device_driver *drv = dev->driver;
809 	int ret = 0;
810 
811 	if (!drv)
812 		return 0;
813 
814 	if (drv->pm) {
815 		if (drv->pm->thaw)
816 			ret = drv->pm->thaw(dev);
817 	} else {
818 		ret = platform_legacy_resume(dev);
819 	}
820 
821 	return ret;
822 }
823 
824 static int platform_pm_thaw_noirq(struct device *dev)
825 {
826 	struct device_driver *drv = dev->driver;
827 	int ret = 0;
828 
829 	if (!drv)
830 		return 0;
831 
832 	if (drv->pm) {
833 		if (drv->pm->thaw_noirq)
834 			ret = drv->pm->thaw_noirq(dev);
835 	} else {
836 		ret = platform_legacy_resume_early(dev);
837 	}
838 
839 	return ret;
840 }
841 
842 static int platform_pm_poweroff(struct device *dev)
843 {
844 	struct device_driver *drv = dev->driver;
845 	int ret = 0;
846 
847 	if (!drv)
848 		return 0;
849 
850 	if (drv->pm) {
851 		if (drv->pm->poweroff)
852 			ret = drv->pm->poweroff(dev);
853 	} else {
854 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
855 	}
856 
857 	return ret;
858 }
859 
860 static int platform_pm_poweroff_noirq(struct device *dev)
861 {
862 	struct device_driver *drv = dev->driver;
863 	int ret = 0;
864 
865 	if (!drv)
866 		return 0;
867 
868 	if (drv->pm) {
869 		if (drv->pm->poweroff_noirq)
870 			ret = drv->pm->poweroff_noirq(dev);
871 	} else {
872 		ret = platform_legacy_suspend_late(dev, PMSG_HIBERNATE);
873 	}
874 
875 	return ret;
876 }
877 
878 static int platform_pm_restore(struct device *dev)
879 {
880 	struct device_driver *drv = dev->driver;
881 	int ret = 0;
882 
883 	if (!drv)
884 		return 0;
885 
886 	if (drv->pm) {
887 		if (drv->pm->restore)
888 			ret = drv->pm->restore(dev);
889 	} else {
890 		ret = platform_legacy_resume(dev);
891 	}
892 
893 	return ret;
894 }
895 
896 static int platform_pm_restore_noirq(struct device *dev)
897 {
898 	struct device_driver *drv = dev->driver;
899 	int ret = 0;
900 
901 	if (!drv)
902 		return 0;
903 
904 	if (drv->pm) {
905 		if (drv->pm->restore_noirq)
906 			ret = drv->pm->restore_noirq(dev);
907 	} else {
908 		ret = platform_legacy_resume_early(dev);
909 	}
910 
911 	return ret;
912 }
913 
914 #else /* !CONFIG_HIBERNATION */
915 
916 #define platform_pm_freeze		NULL
917 #define platform_pm_thaw		NULL
918 #define platform_pm_poweroff		NULL
919 #define platform_pm_restore		NULL
920 #define platform_pm_freeze_noirq	NULL
921 #define platform_pm_thaw_noirq		NULL
922 #define platform_pm_poweroff_noirq	NULL
923 #define platform_pm_restore_noirq	NULL
924 
925 #endif /* !CONFIG_HIBERNATION */
926 
927 static struct dev_pm_ops platform_dev_pm_ops = {
928 	.prepare = platform_pm_prepare,
929 	.complete = platform_pm_complete,
930 	.suspend = platform_pm_suspend,
931 	.resume = platform_pm_resume,
932 	.freeze = platform_pm_freeze,
933 	.thaw = platform_pm_thaw,
934 	.poweroff = platform_pm_poweroff,
935 	.restore = platform_pm_restore,
936 	.suspend_noirq = platform_pm_suspend_noirq,
937 	.resume_noirq = platform_pm_resume_noirq,
938 	.freeze_noirq = platform_pm_freeze_noirq,
939 	.thaw_noirq = platform_pm_thaw_noirq,
940 	.poweroff_noirq = platform_pm_poweroff_noirq,
941 	.restore_noirq = platform_pm_restore_noirq,
942 };
943 
944 #define PLATFORM_PM_OPS_PTR	(&platform_dev_pm_ops)
945 
946 #else /* !CONFIG_PM_SLEEP */
947 
948 #define PLATFORM_PM_OPS_PTR	NULL
949 
950 #endif /* !CONFIG_PM_SLEEP */
951 
952 struct bus_type platform_bus_type = {
953 	.name		= "platform",
954 	.dev_attrs	= platform_dev_attrs,
955 	.match		= platform_match,
956 	.uevent		= platform_uevent,
957 	.pm		= PLATFORM_PM_OPS_PTR,
958 };
959 EXPORT_SYMBOL_GPL(platform_bus_type);
960 
961 int __init platform_bus_init(void)
962 {
963 	int error;
964 
965 	early_platform_cleanup();
966 
967 	error = device_register(&platform_bus);
968 	if (error)
969 		return error;
970 	error =  bus_register(&platform_bus_type);
971 	if (error)
972 		device_unregister(&platform_bus);
973 	return error;
974 }
975 
976 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
977 u64 dma_get_required_mask(struct device *dev)
978 {
979 	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
980 	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
981 	u64 mask;
982 
983 	if (!high_totalram) {
984 		/* convert to mask just covering totalram */
985 		low_totalram = (1 << (fls(low_totalram) - 1));
986 		low_totalram += low_totalram - 1;
987 		mask = low_totalram;
988 	} else {
989 		high_totalram = (1 << (fls(high_totalram) - 1));
990 		high_totalram += high_totalram - 1;
991 		mask = (((u64)high_totalram) << 32) + 0xffffffff;
992 	}
993 	return mask;
994 }
995 EXPORT_SYMBOL_GPL(dma_get_required_mask);
996 #endif
997 
998 static __initdata LIST_HEAD(early_platform_driver_list);
999 static __initdata LIST_HEAD(early_platform_device_list);
1000 
1001 /**
1002  * early_platform_driver_register
1003  * @epdrv: early_platform driver structure
1004  * @buf: string passed from early_param()
1005  */
1006 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1007 					  char *buf)
1008 {
1009 	unsigned long index;
1010 	int n;
1011 
1012 	/* Simply add the driver to the end of the global list.
1013 	 * Drivers will by default be put on the list in compiled-in order.
1014 	 */
1015 	if (!epdrv->list.next) {
1016 		INIT_LIST_HEAD(&epdrv->list);
1017 		list_add_tail(&epdrv->list, &early_platform_driver_list);
1018 	}
1019 
1020 	/* If the user has specified device then make sure the driver
1021 	 * gets prioritized. The driver of the last device specified on
1022 	 * command line will be put first on the list.
1023 	 */
1024 	n = strlen(epdrv->pdrv->driver.name);
1025 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1026 		list_move(&epdrv->list, &early_platform_driver_list);
1027 
1028 		if (!strcmp(buf, epdrv->pdrv->driver.name))
1029 			epdrv->requested_id = -1;
1030 		else if (buf[n] == '.' && strict_strtoul(&buf[n + 1], 10,
1031 							 &index) == 0)
1032 			epdrv->requested_id = index;
1033 		else
1034 			epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1035 	}
1036 
1037 	return 0;
1038 }
1039 
1040 /**
1041  * early_platform_add_devices - add a numbers of early platform devices
1042  * @devs: array of early platform devices to add
1043  * @num: number of early platform devices in array
1044  */
1045 void __init early_platform_add_devices(struct platform_device **devs, int num)
1046 {
1047 	struct device *dev;
1048 	int i;
1049 
1050 	/* simply add the devices to list */
1051 	for (i = 0; i < num; i++) {
1052 		dev = &devs[i]->dev;
1053 
1054 		if (!dev->devres_head.next) {
1055 			INIT_LIST_HEAD(&dev->devres_head);
1056 			list_add_tail(&dev->devres_head,
1057 				      &early_platform_device_list);
1058 		}
1059 	}
1060 }
1061 
1062 /**
1063  * early_platform_driver_register_all
1064  * @class_str: string to identify early platform driver class
1065  */
1066 void __init early_platform_driver_register_all(char *class_str)
1067 {
1068 	/* The "class_str" parameter may or may not be present on the kernel
1069 	 * command line. If it is present then there may be more than one
1070 	 * matching parameter.
1071 	 *
1072 	 * Since we register our early platform drivers using early_param()
1073 	 * we need to make sure that they also get registered in the case
1074 	 * when the parameter is missing from the kernel command line.
1075 	 *
1076 	 * We use parse_early_options() to make sure the early_param() gets
1077 	 * called at least once. The early_param() may be called more than
1078 	 * once since the name of the preferred device may be specified on
1079 	 * the kernel command line. early_platform_driver_register() handles
1080 	 * this case for us.
1081 	 */
1082 	parse_early_options(class_str);
1083 }
1084 
1085 /**
1086  * early_platform_match
1087  * @epdrv: early platform driver structure
1088  * @id: id to match against
1089  */
1090 static  __init struct platform_device *
1091 early_platform_match(struct early_platform_driver *epdrv, int id)
1092 {
1093 	struct platform_device *pd;
1094 
1095 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1096 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1097 			if (pd->id == id)
1098 				return pd;
1099 
1100 	return NULL;
1101 }
1102 
1103 /**
1104  * early_platform_left
1105  * @epdrv: early platform driver structure
1106  * @id: return true if id or above exists
1107  */
1108 static  __init int early_platform_left(struct early_platform_driver *epdrv,
1109 				       int id)
1110 {
1111 	struct platform_device *pd;
1112 
1113 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1114 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1115 			if (pd->id >= id)
1116 				return 1;
1117 
1118 	return 0;
1119 }
1120 
1121 /**
1122  * early_platform_driver_probe_id
1123  * @class_str: string to identify early platform driver class
1124  * @id: id to match against
1125  * @nr_probe: number of platform devices to successfully probe before exiting
1126  */
1127 static int __init early_platform_driver_probe_id(char *class_str,
1128 						 int id,
1129 						 int nr_probe)
1130 {
1131 	struct early_platform_driver *epdrv;
1132 	struct platform_device *match;
1133 	int match_id;
1134 	int n = 0;
1135 	int left = 0;
1136 
1137 	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1138 		/* only use drivers matching our class_str */
1139 		if (strcmp(class_str, epdrv->class_str))
1140 			continue;
1141 
1142 		if (id == -2) {
1143 			match_id = epdrv->requested_id;
1144 			left = 1;
1145 
1146 		} else {
1147 			match_id = id;
1148 			left += early_platform_left(epdrv, id);
1149 
1150 			/* skip requested id */
1151 			switch (epdrv->requested_id) {
1152 			case EARLY_PLATFORM_ID_ERROR:
1153 			case EARLY_PLATFORM_ID_UNSET:
1154 				break;
1155 			default:
1156 				if (epdrv->requested_id == id)
1157 					match_id = EARLY_PLATFORM_ID_UNSET;
1158 			}
1159 		}
1160 
1161 		switch (match_id) {
1162 		case EARLY_PLATFORM_ID_ERROR:
1163 			pr_warning("%s: unable to parse %s parameter\n",
1164 				   class_str, epdrv->pdrv->driver.name);
1165 			/* fall-through */
1166 		case EARLY_PLATFORM_ID_UNSET:
1167 			match = NULL;
1168 			break;
1169 		default:
1170 			match = early_platform_match(epdrv, match_id);
1171 		}
1172 
1173 		if (match) {
1174 			if (epdrv->pdrv->probe(match))
1175 				pr_warning("%s: unable to probe %s early.\n",
1176 					   class_str, match->name);
1177 			else
1178 				n++;
1179 		}
1180 
1181 		if (n >= nr_probe)
1182 			break;
1183 	}
1184 
1185 	if (left)
1186 		return n;
1187 	else
1188 		return -ENODEV;
1189 }
1190 
1191 /**
1192  * early_platform_driver_probe
1193  * @class_str: string to identify early platform driver class
1194  * @nr_probe: number of platform devices to successfully probe before exiting
1195  * @user_only: only probe user specified early platform devices
1196  */
1197 int __init early_platform_driver_probe(char *class_str,
1198 				       int nr_probe,
1199 				       int user_only)
1200 {
1201 	int k, n, i;
1202 
1203 	n = 0;
1204 	for (i = -2; n < nr_probe; i++) {
1205 		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1206 
1207 		if (k < 0)
1208 			break;
1209 
1210 		n += k;
1211 
1212 		if (user_only)
1213 			break;
1214 	}
1215 
1216 	return n;
1217 }
1218 
1219 /**
1220  * early_platform_cleanup - clean up early platform code
1221  */
1222 void __init early_platform_cleanup(void)
1223 {
1224 	struct platform_device *pd, *pd2;
1225 
1226 	/* clean up the devres list used to chain devices */
1227 	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1228 				 dev.devres_head) {
1229 		list_del(&pd->dev.devres_head);
1230 		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1231 	}
1232 }
1233 
1234