xref: /openbmc/linux/drivers/base/platform.c (revision 82ced6fd)
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 static int platform_drv_suspend(struct device *_dev, pm_message_t state)
473 {
474 	struct platform_driver *drv = to_platform_driver(_dev->driver);
475 	struct platform_device *dev = to_platform_device(_dev);
476 
477 	return drv->suspend(dev, state);
478 }
479 
480 static int platform_drv_resume(struct device *_dev)
481 {
482 	struct platform_driver *drv = to_platform_driver(_dev->driver);
483 	struct platform_device *dev = to_platform_device(_dev);
484 
485 	return drv->resume(dev);
486 }
487 
488 /**
489  * platform_driver_register
490  * @drv: platform driver structure
491  */
492 int platform_driver_register(struct platform_driver *drv)
493 {
494 	drv->driver.bus = &platform_bus_type;
495 	if (drv->probe)
496 		drv->driver.probe = platform_drv_probe;
497 	if (drv->remove)
498 		drv->driver.remove = platform_drv_remove;
499 	if (drv->shutdown)
500 		drv->driver.shutdown = platform_drv_shutdown;
501 	if (drv->suspend)
502 		drv->driver.suspend = platform_drv_suspend;
503 	if (drv->resume)
504 		drv->driver.resume = platform_drv_resume;
505 	return driver_register(&drv->driver);
506 }
507 EXPORT_SYMBOL_GPL(platform_driver_register);
508 
509 /**
510  * platform_driver_unregister
511  * @drv: platform driver structure
512  */
513 void platform_driver_unregister(struct platform_driver *drv)
514 {
515 	driver_unregister(&drv->driver);
516 }
517 EXPORT_SYMBOL_GPL(platform_driver_unregister);
518 
519 /**
520  * platform_driver_probe - register driver for non-hotpluggable device
521  * @drv: platform driver structure
522  * @probe: the driver probe routine, probably from an __init section
523  *
524  * Use this instead of platform_driver_register() when you know the device
525  * is not hotpluggable and has already been registered, and you want to
526  * remove its run-once probe() infrastructure from memory after the driver
527  * has bound to the device.
528  *
529  * One typical use for this would be with drivers for controllers integrated
530  * into system-on-chip processors, where the controller devices have been
531  * configured as part of board setup.
532  *
533  * Returns zero if the driver registered and bound to a device, else returns
534  * a negative error code and with the driver not registered.
535  */
536 int __init_or_module platform_driver_probe(struct platform_driver *drv,
537 		int (*probe)(struct platform_device *))
538 {
539 	int retval, code;
540 
541 	/* temporary section violation during probe() */
542 	drv->probe = probe;
543 	retval = code = platform_driver_register(drv);
544 
545 	/* Fixup that section violation, being paranoid about code scanning
546 	 * the list of drivers in order to probe new devices.  Check to see
547 	 * if the probe was successful, and make sure any forced probes of
548 	 * new devices fail.
549 	 */
550 	spin_lock(&platform_bus_type.p->klist_drivers.k_lock);
551 	drv->probe = NULL;
552 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
553 		retval = -ENODEV;
554 	drv->driver.probe = platform_drv_probe_fail;
555 	spin_unlock(&platform_bus_type.p->klist_drivers.k_lock);
556 
557 	if (code != retval)
558 		platform_driver_unregister(drv);
559 	return retval;
560 }
561 EXPORT_SYMBOL_GPL(platform_driver_probe);
562 
563 /* modalias support enables more hands-off userspace setup:
564  * (a) environment variable lets new-style hotplug events work once system is
565  *     fully running:  "modprobe $MODALIAS"
566  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
567  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
568  */
569 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
570 			     char *buf)
571 {
572 	struct platform_device	*pdev = to_platform_device(dev);
573 	int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
574 
575 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
576 }
577 
578 static struct device_attribute platform_dev_attrs[] = {
579 	__ATTR_RO(modalias),
580 	__ATTR_NULL,
581 };
582 
583 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
584 {
585 	struct platform_device	*pdev = to_platform_device(dev);
586 
587 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
588 		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);
589 	return 0;
590 }
591 
592 static const struct platform_device_id *platform_match_id(
593 			struct platform_device_id *id,
594 			struct platform_device *pdev)
595 {
596 	while (id->name[0]) {
597 		if (strcmp(pdev->name, id->name) == 0) {
598 			pdev->id_entry = id;
599 			return id;
600 		}
601 		id++;
602 	}
603 	return NULL;
604 }
605 
606 /**
607  * platform_match - bind platform device to platform driver.
608  * @dev: device.
609  * @drv: driver.
610  *
611  * Platform device IDs are assumed to be encoded like this:
612  * "<name><instance>", where <name> is a short description of the type of
613  * device, like "pci" or "floppy", and <instance> is the enumerated
614  * instance of the device, like '0' or '42'.  Driver IDs are simply
615  * "<name>".  So, extract the <name> from the platform_device structure,
616  * and compare it against the name of the driver. Return whether they match
617  * or not.
618  */
619 static int platform_match(struct device *dev, struct device_driver *drv)
620 {
621 	struct platform_device *pdev = to_platform_device(dev);
622 	struct platform_driver *pdrv = to_platform_driver(drv);
623 
624 	/* match against the id table first */
625 	if (pdrv->id_table)
626 		return platform_match_id(pdrv->id_table, pdev) != NULL;
627 
628 	/* fall-back to driver name match */
629 	return (strcmp(pdev->name, drv->name) == 0);
630 }
631 
632 #ifdef CONFIG_PM_SLEEP
633 
634 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
635 {
636 	int ret = 0;
637 
638 	if (dev->driver && dev->driver->suspend)
639 		ret = dev->driver->suspend(dev, mesg);
640 
641 	return ret;
642 }
643 
644 static int platform_legacy_suspend_late(struct device *dev, pm_message_t mesg)
645 {
646 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
647 	struct platform_device *pdev = to_platform_device(dev);
648 	int ret = 0;
649 
650 	if (dev->driver && pdrv->suspend_late)
651 		ret = pdrv->suspend_late(pdev, mesg);
652 
653 	return ret;
654 }
655 
656 static int platform_legacy_resume_early(struct device *dev)
657 {
658 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
659 	struct platform_device *pdev = to_platform_device(dev);
660 	int ret = 0;
661 
662 	if (dev->driver && pdrv->resume_early)
663 		ret = pdrv->resume_early(pdev);
664 
665 	return ret;
666 }
667 
668 static int platform_legacy_resume(struct device *dev)
669 {
670 	int ret = 0;
671 
672 	if (dev->driver && dev->driver->resume)
673 		ret = dev->driver->resume(dev);
674 
675 	return ret;
676 }
677 
678 static int platform_pm_prepare(struct device *dev)
679 {
680 	struct device_driver *drv = dev->driver;
681 	int ret = 0;
682 
683 	if (drv && drv->pm && drv->pm->prepare)
684 		ret = drv->pm->prepare(dev);
685 
686 	return ret;
687 }
688 
689 static void platform_pm_complete(struct device *dev)
690 {
691 	struct device_driver *drv = dev->driver;
692 
693 	if (drv && drv->pm && drv->pm->complete)
694 		drv->pm->complete(dev);
695 }
696 
697 #ifdef CONFIG_SUSPEND
698 
699 static int platform_pm_suspend(struct device *dev)
700 {
701 	struct device_driver *drv = dev->driver;
702 	int ret = 0;
703 
704 	if (!drv)
705 		return 0;
706 
707 	if (drv->pm) {
708 		if (drv->pm->suspend)
709 			ret = drv->pm->suspend(dev);
710 	} else {
711 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
712 	}
713 
714 	return ret;
715 }
716 
717 static int platform_pm_suspend_noirq(struct device *dev)
718 {
719 	struct device_driver *drv = dev->driver;
720 	int ret = 0;
721 
722 	if (!drv)
723 		return 0;
724 
725 	if (drv->pm) {
726 		if (drv->pm->suspend_noirq)
727 			ret = drv->pm->suspend_noirq(dev);
728 	} else {
729 		ret = platform_legacy_suspend_late(dev, PMSG_SUSPEND);
730 	}
731 
732 	return ret;
733 }
734 
735 static int platform_pm_resume(struct device *dev)
736 {
737 	struct device_driver *drv = dev->driver;
738 	int ret = 0;
739 
740 	if (!drv)
741 		return 0;
742 
743 	if (drv->pm) {
744 		if (drv->pm->resume)
745 			ret = drv->pm->resume(dev);
746 	} else {
747 		ret = platform_legacy_resume(dev);
748 	}
749 
750 	return ret;
751 }
752 
753 static int platform_pm_resume_noirq(struct device *dev)
754 {
755 	struct device_driver *drv = dev->driver;
756 	int ret = 0;
757 
758 	if (!drv)
759 		return 0;
760 
761 	if (drv->pm) {
762 		if (drv->pm->resume_noirq)
763 			ret = drv->pm->resume_noirq(dev);
764 	} else {
765 		ret = platform_legacy_resume_early(dev);
766 	}
767 
768 	return ret;
769 }
770 
771 #else /* !CONFIG_SUSPEND */
772 
773 #define platform_pm_suspend		NULL
774 #define platform_pm_resume		NULL
775 #define platform_pm_suspend_noirq	NULL
776 #define platform_pm_resume_noirq	NULL
777 
778 #endif /* !CONFIG_SUSPEND */
779 
780 #ifdef CONFIG_HIBERNATION
781 
782 static int platform_pm_freeze(struct device *dev)
783 {
784 	struct device_driver *drv = dev->driver;
785 	int ret = 0;
786 
787 	if (!drv)
788 		return 0;
789 
790 	if (drv->pm) {
791 		if (drv->pm->freeze)
792 			ret = drv->pm->freeze(dev);
793 	} else {
794 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
795 	}
796 
797 	return ret;
798 }
799 
800 static int platform_pm_freeze_noirq(struct device *dev)
801 {
802 	struct device_driver *drv = dev->driver;
803 	int ret = 0;
804 
805 	if (!drv)
806 		return 0;
807 
808 	if (drv->pm) {
809 		if (drv->pm->freeze_noirq)
810 			ret = drv->pm->freeze_noirq(dev);
811 	} else {
812 		ret = platform_legacy_suspend_late(dev, PMSG_FREEZE);
813 	}
814 
815 	return ret;
816 }
817 
818 static int platform_pm_thaw(struct device *dev)
819 {
820 	struct device_driver *drv = dev->driver;
821 	int ret = 0;
822 
823 	if (!drv)
824 		return 0;
825 
826 	if (drv->pm) {
827 		if (drv->pm->thaw)
828 			ret = drv->pm->thaw(dev);
829 	} else {
830 		ret = platform_legacy_resume(dev);
831 	}
832 
833 	return ret;
834 }
835 
836 static int platform_pm_thaw_noirq(struct device *dev)
837 {
838 	struct device_driver *drv = dev->driver;
839 	int ret = 0;
840 
841 	if (!drv)
842 		return 0;
843 
844 	if (drv->pm) {
845 		if (drv->pm->thaw_noirq)
846 			ret = drv->pm->thaw_noirq(dev);
847 	} else {
848 		ret = platform_legacy_resume_early(dev);
849 	}
850 
851 	return ret;
852 }
853 
854 static int platform_pm_poweroff(struct device *dev)
855 {
856 	struct device_driver *drv = dev->driver;
857 	int ret = 0;
858 
859 	if (!drv)
860 		return 0;
861 
862 	if (drv->pm) {
863 		if (drv->pm->poweroff)
864 			ret = drv->pm->poweroff(dev);
865 	} else {
866 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
867 	}
868 
869 	return ret;
870 }
871 
872 static int platform_pm_poweroff_noirq(struct device *dev)
873 {
874 	struct device_driver *drv = dev->driver;
875 	int ret = 0;
876 
877 	if (!drv)
878 		return 0;
879 
880 	if (drv->pm) {
881 		if (drv->pm->poweroff_noirq)
882 			ret = drv->pm->poweroff_noirq(dev);
883 	} else {
884 		ret = platform_legacy_suspend_late(dev, PMSG_HIBERNATE);
885 	}
886 
887 	return ret;
888 }
889 
890 static int platform_pm_restore(struct device *dev)
891 {
892 	struct device_driver *drv = dev->driver;
893 	int ret = 0;
894 
895 	if (!drv)
896 		return 0;
897 
898 	if (drv->pm) {
899 		if (drv->pm->restore)
900 			ret = drv->pm->restore(dev);
901 	} else {
902 		ret = platform_legacy_resume(dev);
903 	}
904 
905 	return ret;
906 }
907 
908 static int platform_pm_restore_noirq(struct device *dev)
909 {
910 	struct device_driver *drv = dev->driver;
911 	int ret = 0;
912 
913 	if (!drv)
914 		return 0;
915 
916 	if (drv->pm) {
917 		if (drv->pm->restore_noirq)
918 			ret = drv->pm->restore_noirq(dev);
919 	} else {
920 		ret = platform_legacy_resume_early(dev);
921 	}
922 
923 	return ret;
924 }
925 
926 #else /* !CONFIG_HIBERNATION */
927 
928 #define platform_pm_freeze		NULL
929 #define platform_pm_thaw		NULL
930 #define platform_pm_poweroff		NULL
931 #define platform_pm_restore		NULL
932 #define platform_pm_freeze_noirq	NULL
933 #define platform_pm_thaw_noirq		NULL
934 #define platform_pm_poweroff_noirq	NULL
935 #define platform_pm_restore_noirq	NULL
936 
937 #endif /* !CONFIG_HIBERNATION */
938 
939 static struct dev_pm_ops platform_dev_pm_ops = {
940 	.prepare = platform_pm_prepare,
941 	.complete = platform_pm_complete,
942 	.suspend = platform_pm_suspend,
943 	.resume = platform_pm_resume,
944 	.freeze = platform_pm_freeze,
945 	.thaw = platform_pm_thaw,
946 	.poweroff = platform_pm_poweroff,
947 	.restore = platform_pm_restore,
948 	.suspend_noirq = platform_pm_suspend_noirq,
949 	.resume_noirq = platform_pm_resume_noirq,
950 	.freeze_noirq = platform_pm_freeze_noirq,
951 	.thaw_noirq = platform_pm_thaw_noirq,
952 	.poweroff_noirq = platform_pm_poweroff_noirq,
953 	.restore_noirq = platform_pm_restore_noirq,
954 };
955 
956 #define PLATFORM_PM_OPS_PTR	(&platform_dev_pm_ops)
957 
958 #else /* !CONFIG_PM_SLEEP */
959 
960 #define PLATFORM_PM_OPS_PTR	NULL
961 
962 #endif /* !CONFIG_PM_SLEEP */
963 
964 struct bus_type platform_bus_type = {
965 	.name		= "platform",
966 	.dev_attrs	= platform_dev_attrs,
967 	.match		= platform_match,
968 	.uevent		= platform_uevent,
969 	.pm		= PLATFORM_PM_OPS_PTR,
970 };
971 EXPORT_SYMBOL_GPL(platform_bus_type);
972 
973 int __init platform_bus_init(void)
974 {
975 	int error;
976 
977 	early_platform_cleanup();
978 
979 	error = device_register(&platform_bus);
980 	if (error)
981 		return error;
982 	error =  bus_register(&platform_bus_type);
983 	if (error)
984 		device_unregister(&platform_bus);
985 	return error;
986 }
987 
988 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
989 u64 dma_get_required_mask(struct device *dev)
990 {
991 	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
992 	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
993 	u64 mask;
994 
995 	if (!high_totalram) {
996 		/* convert to mask just covering totalram */
997 		low_totalram = (1 << (fls(low_totalram) - 1));
998 		low_totalram += low_totalram - 1;
999 		mask = low_totalram;
1000 	} else {
1001 		high_totalram = (1 << (fls(high_totalram) - 1));
1002 		high_totalram += high_totalram - 1;
1003 		mask = (((u64)high_totalram) << 32) + 0xffffffff;
1004 	}
1005 	return mask;
1006 }
1007 EXPORT_SYMBOL_GPL(dma_get_required_mask);
1008 #endif
1009 
1010 static __initdata LIST_HEAD(early_platform_driver_list);
1011 static __initdata LIST_HEAD(early_platform_device_list);
1012 
1013 /**
1014  * early_platform_driver_register
1015  * @epdrv: early_platform driver structure
1016  * @buf: string passed from early_param()
1017  */
1018 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1019 					  char *buf)
1020 {
1021 	unsigned long index;
1022 	int n;
1023 
1024 	/* Simply add the driver to the end of the global list.
1025 	 * Drivers will by default be put on the list in compiled-in order.
1026 	 */
1027 	if (!epdrv->list.next) {
1028 		INIT_LIST_HEAD(&epdrv->list);
1029 		list_add_tail(&epdrv->list, &early_platform_driver_list);
1030 	}
1031 
1032 	/* If the user has specified device then make sure the driver
1033 	 * gets prioritized. The driver of the last device specified on
1034 	 * command line will be put first on the list.
1035 	 */
1036 	n = strlen(epdrv->pdrv->driver.name);
1037 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1038 		list_move(&epdrv->list, &early_platform_driver_list);
1039 
1040 		if (!strcmp(buf, epdrv->pdrv->driver.name))
1041 			epdrv->requested_id = -1;
1042 		else if (buf[n] == '.' && strict_strtoul(&buf[n + 1], 10,
1043 							 &index) == 0)
1044 			epdrv->requested_id = index;
1045 		else
1046 			epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1047 	}
1048 
1049 	return 0;
1050 }
1051 
1052 /**
1053  * early_platform_add_devices - add a numbers of early platform devices
1054  * @devs: array of early platform devices to add
1055  * @num: number of early platform devices in array
1056  */
1057 void __init early_platform_add_devices(struct platform_device **devs, int num)
1058 {
1059 	struct device *dev;
1060 	int i;
1061 
1062 	/* simply add the devices to list */
1063 	for (i = 0; i < num; i++) {
1064 		dev = &devs[i]->dev;
1065 
1066 		if (!dev->devres_head.next) {
1067 			INIT_LIST_HEAD(&dev->devres_head);
1068 			list_add_tail(&dev->devres_head,
1069 				      &early_platform_device_list);
1070 		}
1071 	}
1072 }
1073 
1074 /**
1075  * early_platform_driver_register_all
1076  * @class_str: string to identify early platform driver class
1077  */
1078 void __init early_platform_driver_register_all(char *class_str)
1079 {
1080 	/* The "class_str" parameter may or may not be present on the kernel
1081 	 * command line. If it is present then there may be more than one
1082 	 * matching parameter.
1083 	 *
1084 	 * Since we register our early platform drivers using early_param()
1085 	 * we need to make sure that they also get registered in the case
1086 	 * when the parameter is missing from the kernel command line.
1087 	 *
1088 	 * We use parse_early_options() to make sure the early_param() gets
1089 	 * called at least once. The early_param() may be called more than
1090 	 * once since the name of the preferred device may be specified on
1091 	 * the kernel command line. early_platform_driver_register() handles
1092 	 * this case for us.
1093 	 */
1094 	parse_early_options(class_str);
1095 }
1096 
1097 /**
1098  * early_platform_match
1099  * @epdrv: early platform driver structure
1100  * @id: id to match against
1101  */
1102 static  __init struct platform_device *
1103 early_platform_match(struct early_platform_driver *epdrv, int id)
1104 {
1105 	struct platform_device *pd;
1106 
1107 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1108 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1109 			if (pd->id == id)
1110 				return pd;
1111 
1112 	return NULL;
1113 }
1114 
1115 /**
1116  * early_platform_left
1117  * @epdrv: early platform driver structure
1118  * @id: return true if id or above exists
1119  */
1120 static  __init int early_platform_left(struct early_platform_driver *epdrv,
1121 				       int id)
1122 {
1123 	struct platform_device *pd;
1124 
1125 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1126 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1127 			if (pd->id >= id)
1128 				return 1;
1129 
1130 	return 0;
1131 }
1132 
1133 /**
1134  * early_platform_driver_probe_id
1135  * @class_str: string to identify early platform driver class
1136  * @id: id to match against
1137  * @nr_probe: number of platform devices to successfully probe before exiting
1138  */
1139 static int __init early_platform_driver_probe_id(char *class_str,
1140 						 int id,
1141 						 int nr_probe)
1142 {
1143 	struct early_platform_driver *epdrv;
1144 	struct platform_device *match;
1145 	int match_id;
1146 	int n = 0;
1147 	int left = 0;
1148 
1149 	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1150 		/* only use drivers matching our class_str */
1151 		if (strcmp(class_str, epdrv->class_str))
1152 			continue;
1153 
1154 		if (id == -2) {
1155 			match_id = epdrv->requested_id;
1156 			left = 1;
1157 
1158 		} else {
1159 			match_id = id;
1160 			left += early_platform_left(epdrv, id);
1161 
1162 			/* skip requested id */
1163 			switch (epdrv->requested_id) {
1164 			case EARLY_PLATFORM_ID_ERROR:
1165 			case EARLY_PLATFORM_ID_UNSET:
1166 				break;
1167 			default:
1168 				if (epdrv->requested_id == id)
1169 					match_id = EARLY_PLATFORM_ID_UNSET;
1170 			}
1171 		}
1172 
1173 		switch (match_id) {
1174 		case EARLY_PLATFORM_ID_ERROR:
1175 			pr_warning("%s: unable to parse %s parameter\n",
1176 				   class_str, epdrv->pdrv->driver.name);
1177 			/* fall-through */
1178 		case EARLY_PLATFORM_ID_UNSET:
1179 			match = NULL;
1180 			break;
1181 		default:
1182 			match = early_platform_match(epdrv, match_id);
1183 		}
1184 
1185 		if (match) {
1186 			if (epdrv->pdrv->probe(match))
1187 				pr_warning("%s: unable to probe %s early.\n",
1188 					   class_str, match->name);
1189 			else
1190 				n++;
1191 		}
1192 
1193 		if (n >= nr_probe)
1194 			break;
1195 	}
1196 
1197 	if (left)
1198 		return n;
1199 	else
1200 		return -ENODEV;
1201 }
1202 
1203 /**
1204  * early_platform_driver_probe
1205  * @class_str: string to identify early platform driver class
1206  * @nr_probe: number of platform devices to successfully probe before exiting
1207  * @user_only: only probe user specified early platform devices
1208  */
1209 int __init early_platform_driver_probe(char *class_str,
1210 				       int nr_probe,
1211 				       int user_only)
1212 {
1213 	int k, n, i;
1214 
1215 	n = 0;
1216 	for (i = -2; n < nr_probe; i++) {
1217 		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1218 
1219 		if (k < 0)
1220 			break;
1221 
1222 		n += k;
1223 
1224 		if (user_only)
1225 			break;
1226 	}
1227 
1228 	return n;
1229 }
1230 
1231 /**
1232  * early_platform_cleanup - clean up early platform code
1233  */
1234 void __init early_platform_cleanup(void)
1235 {
1236 	struct platform_device *pd, *pd2;
1237 
1238 	/* clean up the devres list used to chain devices */
1239 	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1240 				 dev.devres_head) {
1241 		list_del(&pd->dev.devres_head);
1242 		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1243 	}
1244 }
1245 
1246