xref: /openbmc/linux/drivers/base/platform.c (revision 9c1f8594)
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/string.h>
14 #include <linux/platform_device.h>
15 #include <linux/of_device.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/dma-mapping.h>
19 #include <linux/bootmem.h>
20 #include <linux/err.h>
21 #include <linux/slab.h>
22 #include <linux/pm_runtime.h>
23 
24 #include "base.h"
25 
26 #define to_platform_driver(drv)	(container_of((drv), struct platform_driver, \
27 				 driver))
28 
29 struct device platform_bus = {
30 	.init_name	= "platform",
31 };
32 EXPORT_SYMBOL_GPL(platform_bus);
33 
34 /**
35  * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
36  * @pdev: platform device
37  *
38  * This is called before platform_device_add() such that any pdev_archdata may
39  * be setup before the platform_notifier is called.  So if a user needs to
40  * manipulate any relevant information in the pdev_archdata they can do:
41  *
42  * 	platform_devic_alloc()
43  * 	... manipulate ...
44  * 	platform_device_add()
45  *
46  * And if they don't care they can just call platform_device_register() and
47  * everything will just work out.
48  */
49 void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
50 {
51 }
52 
53 /**
54  * platform_get_resource - get a resource for a device
55  * @dev: platform device
56  * @type: resource type
57  * @num: resource index
58  */
59 struct resource *platform_get_resource(struct platform_device *dev,
60 				       unsigned int type, unsigned int num)
61 {
62 	int i;
63 
64 	for (i = 0; i < dev->num_resources; i++) {
65 		struct resource *r = &dev->resource[i];
66 
67 		if (type == resource_type(r) && num-- == 0)
68 			return r;
69 	}
70 	return NULL;
71 }
72 EXPORT_SYMBOL_GPL(platform_get_resource);
73 
74 /**
75  * platform_get_irq - get an IRQ for a device
76  * @dev: platform device
77  * @num: IRQ number index
78  */
79 int platform_get_irq(struct platform_device *dev, unsigned int num)
80 {
81 	struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
82 
83 	return r ? r->start : -ENXIO;
84 }
85 EXPORT_SYMBOL_GPL(platform_get_irq);
86 
87 /**
88  * platform_get_resource_byname - get a resource for a device by name
89  * @dev: platform device
90  * @type: resource type
91  * @name: resource name
92  */
93 struct resource *platform_get_resource_byname(struct platform_device *dev,
94 					      unsigned int type,
95 					      const char *name)
96 {
97 	int i;
98 
99 	for (i = 0; i < dev->num_resources; i++) {
100 		struct resource *r = &dev->resource[i];
101 
102 		if (type == resource_type(r) && !strcmp(r->name, name))
103 			return r;
104 	}
105 	return NULL;
106 }
107 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
108 
109 /**
110  * platform_get_irq - get an IRQ for a device
111  * @dev: platform device
112  * @name: IRQ name
113  */
114 int platform_get_irq_byname(struct platform_device *dev, const char *name)
115 {
116 	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
117 							  name);
118 
119 	return r ? r->start : -ENXIO;
120 }
121 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
122 
123 /**
124  * platform_add_devices - add a numbers of platform devices
125  * @devs: array of platform devices to add
126  * @num: number of platform devices in array
127  */
128 int platform_add_devices(struct platform_device **devs, int num)
129 {
130 	int i, ret = 0;
131 
132 	for (i = 0; i < num; i++) {
133 		ret = platform_device_register(devs[i]);
134 		if (ret) {
135 			while (--i >= 0)
136 				platform_device_unregister(devs[i]);
137 			break;
138 		}
139 	}
140 
141 	return ret;
142 }
143 EXPORT_SYMBOL_GPL(platform_add_devices);
144 
145 struct platform_object {
146 	struct platform_device pdev;
147 	char name[1];
148 };
149 
150 /**
151  * platform_device_put - destroy a platform device
152  * @pdev: platform device to free
153  *
154  * Free all memory associated with a platform device.  This function must
155  * _only_ be externally called in error cases.  All other usage is a bug.
156  */
157 void platform_device_put(struct platform_device *pdev)
158 {
159 	if (pdev)
160 		put_device(&pdev->dev);
161 }
162 EXPORT_SYMBOL_GPL(platform_device_put);
163 
164 static void platform_device_release(struct device *dev)
165 {
166 	struct platform_object *pa = container_of(dev, struct platform_object,
167 						  pdev.dev);
168 
169 	of_device_node_put(&pa->pdev.dev);
170 	kfree(pa->pdev.dev.platform_data);
171 	kfree(pa->pdev.mfd_cell);
172 	kfree(pa->pdev.resource);
173 	kfree(pa);
174 }
175 
176 /**
177  * platform_device_alloc - create a platform device
178  * @name: base name of the device we're adding
179  * @id: instance id
180  *
181  * Create a platform device object which can have other objects attached
182  * to it, and which will have attached objects freed when it is released.
183  */
184 struct platform_device *platform_device_alloc(const char *name, int id)
185 {
186 	struct platform_object *pa;
187 
188 	pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
189 	if (pa) {
190 		strcpy(pa->name, name);
191 		pa->pdev.name = pa->name;
192 		pa->pdev.id = id;
193 		device_initialize(&pa->pdev.dev);
194 		pa->pdev.dev.release = platform_device_release;
195 		arch_setup_pdev_archdata(&pa->pdev);
196 	}
197 
198 	return pa ? &pa->pdev : NULL;
199 }
200 EXPORT_SYMBOL_GPL(platform_device_alloc);
201 
202 /**
203  * platform_device_add_resources - add resources to a platform device
204  * @pdev: platform device allocated by platform_device_alloc to add resources to
205  * @res: set of resources that needs to be allocated for the device
206  * @num: number of resources
207  *
208  * Add a copy of the resources to the platform device.  The memory
209  * associated with the resources will be freed when the platform device is
210  * released.
211  */
212 int platform_device_add_resources(struct platform_device *pdev,
213 				  const struct resource *res, unsigned int num)
214 {
215 	struct resource *r = NULL;
216 
217 	if (res) {
218 		r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
219 		if (!r)
220 			return -ENOMEM;
221 	}
222 
223 	kfree(pdev->resource);
224 	pdev->resource = r;
225 	pdev->num_resources = num;
226 	return 0;
227 }
228 EXPORT_SYMBOL_GPL(platform_device_add_resources);
229 
230 /**
231  * platform_device_add_data - add platform-specific data to a platform device
232  * @pdev: platform device allocated by platform_device_alloc to add resources to
233  * @data: platform specific data for this platform device
234  * @size: size of platform specific data
235  *
236  * Add a copy of platform specific data to the platform device's
237  * platform_data pointer.  The memory associated with the platform data
238  * will be freed when the platform device is released.
239  */
240 int platform_device_add_data(struct platform_device *pdev, const void *data,
241 			     size_t size)
242 {
243 	void *d = NULL;
244 
245 	if (data) {
246 		d = kmemdup(data, size, GFP_KERNEL);
247 		if (!d)
248 			return -ENOMEM;
249 	}
250 
251 	kfree(pdev->dev.platform_data);
252 	pdev->dev.platform_data = d;
253 	return 0;
254 }
255 EXPORT_SYMBOL_GPL(platform_device_add_data);
256 
257 /**
258  * platform_device_add - add a platform device to device hierarchy
259  * @pdev: platform device we're adding
260  *
261  * This is part 2 of platform_device_register(), though may be called
262  * separately _iff_ pdev was allocated by platform_device_alloc().
263  */
264 int platform_device_add(struct platform_device *pdev)
265 {
266 	int i, ret = 0;
267 
268 	if (!pdev)
269 		return -EINVAL;
270 
271 	if (!pdev->dev.parent)
272 		pdev->dev.parent = &platform_bus;
273 
274 	pdev->dev.bus = &platform_bus_type;
275 
276 	if (pdev->id != -1)
277 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
278 	else
279 		dev_set_name(&pdev->dev, "%s", pdev->name);
280 
281 	for (i = 0; i < pdev->num_resources; i++) {
282 		struct resource *p, *r = &pdev->resource[i];
283 
284 		if (r->name == NULL)
285 			r->name = dev_name(&pdev->dev);
286 
287 		p = r->parent;
288 		if (!p) {
289 			if (resource_type(r) == IORESOURCE_MEM)
290 				p = &iomem_resource;
291 			else if (resource_type(r) == IORESOURCE_IO)
292 				p = &ioport_resource;
293 		}
294 
295 		if (p && insert_resource(p, r)) {
296 			printk(KERN_ERR
297 			       "%s: failed to claim resource %d\n",
298 			       dev_name(&pdev->dev), i);
299 			ret = -EBUSY;
300 			goto failed;
301 		}
302 	}
303 
304 	pr_debug("Registering platform device '%s'. Parent at %s\n",
305 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
306 
307 	ret = device_add(&pdev->dev);
308 	if (ret == 0)
309 		return ret;
310 
311  failed:
312 	while (--i >= 0) {
313 		struct resource *r = &pdev->resource[i];
314 		unsigned long type = resource_type(r);
315 
316 		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
317 			release_resource(r);
318 	}
319 
320 	return ret;
321 }
322 EXPORT_SYMBOL_GPL(platform_device_add);
323 
324 /**
325  * platform_device_del - remove a platform-level device
326  * @pdev: platform device we're removing
327  *
328  * Note that this function will also release all memory- and port-based
329  * resources owned by the device (@dev->resource).  This function must
330  * _only_ be externally called in error cases.  All other usage is a bug.
331  */
332 void platform_device_del(struct platform_device *pdev)
333 {
334 	int i;
335 
336 	if (pdev) {
337 		device_del(&pdev->dev);
338 
339 		for (i = 0; i < pdev->num_resources; i++) {
340 			struct resource *r = &pdev->resource[i];
341 			unsigned long type = resource_type(r);
342 
343 			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
344 				release_resource(r);
345 		}
346 	}
347 }
348 EXPORT_SYMBOL_GPL(platform_device_del);
349 
350 /**
351  * platform_device_register - add a platform-level device
352  * @pdev: platform device we're adding
353  */
354 int platform_device_register(struct platform_device *pdev)
355 {
356 	device_initialize(&pdev->dev);
357 	arch_setup_pdev_archdata(pdev);
358 	return platform_device_add(pdev);
359 }
360 EXPORT_SYMBOL_GPL(platform_device_register);
361 
362 /**
363  * platform_device_unregister - unregister a platform-level device
364  * @pdev: platform device we're unregistering
365  *
366  * Unregistration is done in 2 steps. First we release all resources
367  * and remove it from the subsystem, then we drop reference count by
368  * calling platform_device_put().
369  */
370 void platform_device_unregister(struct platform_device *pdev)
371 {
372 	platform_device_del(pdev);
373 	platform_device_put(pdev);
374 }
375 EXPORT_SYMBOL_GPL(platform_device_unregister);
376 
377 /**
378  * platform_device_register_resndata - add a platform-level device with
379  * resources and platform-specific data
380  *
381  * @parent: parent device for the device we're adding
382  * @name: base name of the device we're adding
383  * @id: instance id
384  * @res: set of resources that needs to be allocated for the device
385  * @num: number of resources
386  * @data: platform specific data for this platform device
387  * @size: size of platform specific data
388  *
389  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
390  */
391 struct platform_device *platform_device_register_resndata(
392 		struct device *parent,
393 		const char *name, int id,
394 		const struct resource *res, unsigned int num,
395 		const void *data, size_t size)
396 {
397 	int ret = -ENOMEM;
398 	struct platform_device *pdev;
399 
400 	pdev = platform_device_alloc(name, id);
401 	if (!pdev)
402 		goto err;
403 
404 	pdev->dev.parent = parent;
405 
406 	ret = platform_device_add_resources(pdev, res, num);
407 	if (ret)
408 		goto err;
409 
410 	ret = platform_device_add_data(pdev, data, size);
411 	if (ret)
412 		goto err;
413 
414 	ret = platform_device_add(pdev);
415 	if (ret) {
416 err:
417 		platform_device_put(pdev);
418 		return ERR_PTR(ret);
419 	}
420 
421 	return pdev;
422 }
423 EXPORT_SYMBOL_GPL(platform_device_register_resndata);
424 
425 static int platform_drv_probe(struct device *_dev)
426 {
427 	struct platform_driver *drv = to_platform_driver(_dev->driver);
428 	struct platform_device *dev = to_platform_device(_dev);
429 
430 	return drv->probe(dev);
431 }
432 
433 static int platform_drv_probe_fail(struct device *_dev)
434 {
435 	return -ENXIO;
436 }
437 
438 static int platform_drv_remove(struct device *_dev)
439 {
440 	struct platform_driver *drv = to_platform_driver(_dev->driver);
441 	struct platform_device *dev = to_platform_device(_dev);
442 
443 	return drv->remove(dev);
444 }
445 
446 static void platform_drv_shutdown(struct device *_dev)
447 {
448 	struct platform_driver *drv = to_platform_driver(_dev->driver);
449 	struct platform_device *dev = to_platform_device(_dev);
450 
451 	drv->shutdown(dev);
452 }
453 
454 /**
455  * platform_driver_register - register a driver for platform-level devices
456  * @drv: platform driver structure
457  */
458 int platform_driver_register(struct platform_driver *drv)
459 {
460 	drv->driver.bus = &platform_bus_type;
461 	if (drv->probe)
462 		drv->driver.probe = platform_drv_probe;
463 	if (drv->remove)
464 		drv->driver.remove = platform_drv_remove;
465 	if (drv->shutdown)
466 		drv->driver.shutdown = platform_drv_shutdown;
467 
468 	return driver_register(&drv->driver);
469 }
470 EXPORT_SYMBOL_GPL(platform_driver_register);
471 
472 /**
473  * platform_driver_unregister - unregister a driver for platform-level devices
474  * @drv: platform driver structure
475  */
476 void platform_driver_unregister(struct platform_driver *drv)
477 {
478 	driver_unregister(&drv->driver);
479 }
480 EXPORT_SYMBOL_GPL(platform_driver_unregister);
481 
482 /**
483  * platform_driver_probe - register driver for non-hotpluggable device
484  * @drv: platform driver structure
485  * @probe: the driver probe routine, probably from an __init section
486  *
487  * Use this instead of platform_driver_register() when you know the device
488  * is not hotpluggable and has already been registered, and you want to
489  * remove its run-once probe() infrastructure from memory after the driver
490  * has bound to the device.
491  *
492  * One typical use for this would be with drivers for controllers integrated
493  * into system-on-chip processors, where the controller devices have been
494  * configured as part of board setup.
495  *
496  * Returns zero if the driver registered and bound to a device, else returns
497  * a negative error code and with the driver not registered.
498  */
499 int __init_or_module platform_driver_probe(struct platform_driver *drv,
500 		int (*probe)(struct platform_device *))
501 {
502 	int retval, code;
503 
504 	/* make sure driver won't have bind/unbind attributes */
505 	drv->driver.suppress_bind_attrs = true;
506 
507 	/* temporary section violation during probe() */
508 	drv->probe = probe;
509 	retval = code = platform_driver_register(drv);
510 
511 	/*
512 	 * Fixup that section violation, being paranoid about code scanning
513 	 * the list of drivers in order to probe new devices.  Check to see
514 	 * if the probe was successful, and make sure any forced probes of
515 	 * new devices fail.
516 	 */
517 	spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
518 	drv->probe = NULL;
519 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
520 		retval = -ENODEV;
521 	drv->driver.probe = platform_drv_probe_fail;
522 	spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
523 
524 	if (code != retval)
525 		platform_driver_unregister(drv);
526 	return retval;
527 }
528 EXPORT_SYMBOL_GPL(platform_driver_probe);
529 
530 /**
531  * platform_create_bundle - register driver and create corresponding device
532  * @driver: platform driver structure
533  * @probe: the driver probe routine, probably from an __init section
534  * @res: set of resources that needs to be allocated for the device
535  * @n_res: number of resources
536  * @data: platform specific data for this platform device
537  * @size: size of platform specific data
538  *
539  * Use this in legacy-style modules that probe hardware directly and
540  * register a single platform device and corresponding platform driver.
541  *
542  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
543  */
544 struct platform_device * __init_or_module platform_create_bundle(
545 			struct platform_driver *driver,
546 			int (*probe)(struct platform_device *),
547 			struct resource *res, unsigned int n_res,
548 			const void *data, size_t size)
549 {
550 	struct platform_device *pdev;
551 	int error;
552 
553 	pdev = platform_device_alloc(driver->driver.name, -1);
554 	if (!pdev) {
555 		error = -ENOMEM;
556 		goto err_out;
557 	}
558 
559 	error = platform_device_add_resources(pdev, res, n_res);
560 	if (error)
561 		goto err_pdev_put;
562 
563 	error = platform_device_add_data(pdev, data, size);
564 	if (error)
565 		goto err_pdev_put;
566 
567 	error = platform_device_add(pdev);
568 	if (error)
569 		goto err_pdev_put;
570 
571 	error = platform_driver_probe(driver, probe);
572 	if (error)
573 		goto err_pdev_del;
574 
575 	return pdev;
576 
577 err_pdev_del:
578 	platform_device_del(pdev);
579 err_pdev_put:
580 	platform_device_put(pdev);
581 err_out:
582 	return ERR_PTR(error);
583 }
584 EXPORT_SYMBOL_GPL(platform_create_bundle);
585 
586 /* modalias support enables more hands-off userspace setup:
587  * (a) environment variable lets new-style hotplug events work once system is
588  *     fully running:  "modprobe $MODALIAS"
589  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
590  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
591  */
592 static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
593 			     char *buf)
594 {
595 	struct platform_device	*pdev = to_platform_device(dev);
596 	int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);
597 
598 	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
599 }
600 
601 static struct device_attribute platform_dev_attrs[] = {
602 	__ATTR_RO(modalias),
603 	__ATTR_NULL,
604 };
605 
606 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
607 {
608 	struct platform_device	*pdev = to_platform_device(dev);
609 	int rc;
610 
611 	/* Some devices have extra OF data and an OF-style MODALIAS */
612 	rc = of_device_uevent(dev,env);
613 	if (rc != -ENODEV)
614 		return rc;
615 
616 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
617 		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);
618 	return 0;
619 }
620 
621 static const struct platform_device_id *platform_match_id(
622 			const struct platform_device_id *id,
623 			struct platform_device *pdev)
624 {
625 	while (id->name[0]) {
626 		if (strcmp(pdev->name, id->name) == 0) {
627 			pdev->id_entry = id;
628 			return id;
629 		}
630 		id++;
631 	}
632 	return NULL;
633 }
634 
635 /**
636  * platform_match - bind platform device to platform driver.
637  * @dev: device.
638  * @drv: driver.
639  *
640  * Platform device IDs are assumed to be encoded like this:
641  * "<name><instance>", where <name> is a short description of the type of
642  * device, like "pci" or "floppy", and <instance> is the enumerated
643  * instance of the device, like '0' or '42'.  Driver IDs are simply
644  * "<name>".  So, extract the <name> from the platform_device structure,
645  * and compare it against the name of the driver. Return whether they match
646  * or not.
647  */
648 static int platform_match(struct device *dev, struct device_driver *drv)
649 {
650 	struct platform_device *pdev = to_platform_device(dev);
651 	struct platform_driver *pdrv = to_platform_driver(drv);
652 
653 	/* Attempt an OF style match first */
654 	if (of_driver_match_device(dev, drv))
655 		return 1;
656 
657 	/* Then try to match against the id table */
658 	if (pdrv->id_table)
659 		return platform_match_id(pdrv->id_table, pdev) != NULL;
660 
661 	/* fall-back to driver name match */
662 	return (strcmp(pdev->name, drv->name) == 0);
663 }
664 
665 #ifdef CONFIG_PM_SLEEP
666 
667 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
668 {
669 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
670 	struct platform_device *pdev = to_platform_device(dev);
671 	int ret = 0;
672 
673 	if (dev->driver && pdrv->suspend)
674 		ret = pdrv->suspend(pdev, mesg);
675 
676 	return ret;
677 }
678 
679 static int platform_legacy_resume(struct device *dev)
680 {
681 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
682 	struct platform_device *pdev = to_platform_device(dev);
683 	int ret = 0;
684 
685 	if (dev->driver && pdrv->resume)
686 		ret = pdrv->resume(pdev);
687 
688 	return ret;
689 }
690 
691 int platform_pm_prepare(struct device *dev)
692 {
693 	struct device_driver *drv = dev->driver;
694 	int ret = 0;
695 
696 	if (drv && drv->pm && drv->pm->prepare)
697 		ret = drv->pm->prepare(dev);
698 
699 	return ret;
700 }
701 
702 void platform_pm_complete(struct device *dev)
703 {
704 	struct device_driver *drv = dev->driver;
705 
706 	if (drv && drv->pm && drv->pm->complete)
707 		drv->pm->complete(dev);
708 }
709 
710 #endif /* CONFIG_PM_SLEEP */
711 
712 #ifdef CONFIG_SUSPEND
713 
714 int platform_pm_suspend(struct device *dev)
715 {
716 	struct device_driver *drv = dev->driver;
717 	int ret = 0;
718 
719 	if (!drv)
720 		return 0;
721 
722 	if (drv->pm) {
723 		if (drv->pm->suspend)
724 			ret = drv->pm->suspend(dev);
725 	} else {
726 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
727 	}
728 
729 	return ret;
730 }
731 
732 int platform_pm_suspend_noirq(struct device *dev)
733 {
734 	struct device_driver *drv = dev->driver;
735 	int ret = 0;
736 
737 	if (!drv)
738 		return 0;
739 
740 	if (drv->pm) {
741 		if (drv->pm->suspend_noirq)
742 			ret = drv->pm->suspend_noirq(dev);
743 	}
744 
745 	return ret;
746 }
747 
748 int platform_pm_resume(struct device *dev)
749 {
750 	struct device_driver *drv = dev->driver;
751 	int ret = 0;
752 
753 	if (!drv)
754 		return 0;
755 
756 	if (drv->pm) {
757 		if (drv->pm->resume)
758 			ret = drv->pm->resume(dev);
759 	} else {
760 		ret = platform_legacy_resume(dev);
761 	}
762 
763 	return ret;
764 }
765 
766 int platform_pm_resume_noirq(struct device *dev)
767 {
768 	struct device_driver *drv = dev->driver;
769 	int ret = 0;
770 
771 	if (!drv)
772 		return 0;
773 
774 	if (drv->pm) {
775 		if (drv->pm->resume_noirq)
776 			ret = drv->pm->resume_noirq(dev);
777 	}
778 
779 	return ret;
780 }
781 
782 #endif /* CONFIG_SUSPEND */
783 
784 #ifdef CONFIG_HIBERNATE_CALLBACKS
785 
786 int platform_pm_freeze(struct device *dev)
787 {
788 	struct device_driver *drv = dev->driver;
789 	int ret = 0;
790 
791 	if (!drv)
792 		return 0;
793 
794 	if (drv->pm) {
795 		if (drv->pm->freeze)
796 			ret = drv->pm->freeze(dev);
797 	} else {
798 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
799 	}
800 
801 	return ret;
802 }
803 
804 int platform_pm_freeze_noirq(struct device *dev)
805 {
806 	struct device_driver *drv = dev->driver;
807 	int ret = 0;
808 
809 	if (!drv)
810 		return 0;
811 
812 	if (drv->pm) {
813 		if (drv->pm->freeze_noirq)
814 			ret = drv->pm->freeze_noirq(dev);
815 	}
816 
817 	return ret;
818 }
819 
820 int platform_pm_thaw(struct device *dev)
821 {
822 	struct device_driver *drv = dev->driver;
823 	int ret = 0;
824 
825 	if (!drv)
826 		return 0;
827 
828 	if (drv->pm) {
829 		if (drv->pm->thaw)
830 			ret = drv->pm->thaw(dev);
831 	} else {
832 		ret = platform_legacy_resume(dev);
833 	}
834 
835 	return ret;
836 }
837 
838 int platform_pm_thaw_noirq(struct device *dev)
839 {
840 	struct device_driver *drv = dev->driver;
841 	int ret = 0;
842 
843 	if (!drv)
844 		return 0;
845 
846 	if (drv->pm) {
847 		if (drv->pm->thaw_noirq)
848 			ret = drv->pm->thaw_noirq(dev);
849 	}
850 
851 	return ret;
852 }
853 
854 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 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 	}
884 
885 	return ret;
886 }
887 
888 int platform_pm_restore(struct device *dev)
889 {
890 	struct device_driver *drv = dev->driver;
891 	int ret = 0;
892 
893 	if (!drv)
894 		return 0;
895 
896 	if (drv->pm) {
897 		if (drv->pm->restore)
898 			ret = drv->pm->restore(dev);
899 	} else {
900 		ret = platform_legacy_resume(dev);
901 	}
902 
903 	return ret;
904 }
905 
906 int platform_pm_restore_noirq(struct device *dev)
907 {
908 	struct device_driver *drv = dev->driver;
909 	int ret = 0;
910 
911 	if (!drv)
912 		return 0;
913 
914 	if (drv->pm) {
915 		if (drv->pm->restore_noirq)
916 			ret = drv->pm->restore_noirq(dev);
917 	}
918 
919 	return ret;
920 }
921 
922 #endif /* CONFIG_HIBERNATE_CALLBACKS */
923 
924 static const struct dev_pm_ops platform_dev_pm_ops = {
925 	.runtime_suspend = pm_generic_runtime_suspend,
926 	.runtime_resume = pm_generic_runtime_resume,
927 	.runtime_idle = pm_generic_runtime_idle,
928 	USE_PLATFORM_PM_SLEEP_OPS
929 };
930 
931 struct bus_type platform_bus_type = {
932 	.name		= "platform",
933 	.dev_attrs	= platform_dev_attrs,
934 	.match		= platform_match,
935 	.uevent		= platform_uevent,
936 	.pm		= &platform_dev_pm_ops,
937 };
938 EXPORT_SYMBOL_GPL(platform_bus_type);
939 
940 int __init platform_bus_init(void)
941 {
942 	int error;
943 
944 	early_platform_cleanup();
945 
946 	error = device_register(&platform_bus);
947 	if (error)
948 		return error;
949 	error =  bus_register(&platform_bus_type);
950 	if (error)
951 		device_unregister(&platform_bus);
952 	return error;
953 }
954 
955 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
956 u64 dma_get_required_mask(struct device *dev)
957 {
958 	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
959 	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
960 	u64 mask;
961 
962 	if (!high_totalram) {
963 		/* convert to mask just covering totalram */
964 		low_totalram = (1 << (fls(low_totalram) - 1));
965 		low_totalram += low_totalram - 1;
966 		mask = low_totalram;
967 	} else {
968 		high_totalram = (1 << (fls(high_totalram) - 1));
969 		high_totalram += high_totalram - 1;
970 		mask = (((u64)high_totalram) << 32) + 0xffffffff;
971 	}
972 	return mask;
973 }
974 EXPORT_SYMBOL_GPL(dma_get_required_mask);
975 #endif
976 
977 static __initdata LIST_HEAD(early_platform_driver_list);
978 static __initdata LIST_HEAD(early_platform_device_list);
979 
980 /**
981  * early_platform_driver_register - register early platform driver
982  * @epdrv: early_platform driver structure
983  * @buf: string passed from early_param()
984  *
985  * Helper function for early_platform_init() / early_platform_init_buffer()
986  */
987 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
988 					  char *buf)
989 {
990 	char *tmp;
991 	int n;
992 
993 	/* Simply add the driver to the end of the global list.
994 	 * Drivers will by default be put on the list in compiled-in order.
995 	 */
996 	if (!epdrv->list.next) {
997 		INIT_LIST_HEAD(&epdrv->list);
998 		list_add_tail(&epdrv->list, &early_platform_driver_list);
999 	}
1000 
1001 	/* If the user has specified device then make sure the driver
1002 	 * gets prioritized. The driver of the last device specified on
1003 	 * command line will be put first on the list.
1004 	 */
1005 	n = strlen(epdrv->pdrv->driver.name);
1006 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1007 		list_move(&epdrv->list, &early_platform_driver_list);
1008 
1009 		/* Allow passing parameters after device name */
1010 		if (buf[n] == '\0' || buf[n] == ',')
1011 			epdrv->requested_id = -1;
1012 		else {
1013 			epdrv->requested_id = simple_strtoul(&buf[n + 1],
1014 							     &tmp, 10);
1015 
1016 			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1017 				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1018 				n = 0;
1019 			} else
1020 				n += strcspn(&buf[n + 1], ",") + 1;
1021 		}
1022 
1023 		if (buf[n] == ',')
1024 			n++;
1025 
1026 		if (epdrv->bufsize) {
1027 			memcpy(epdrv->buffer, &buf[n],
1028 			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1029 			epdrv->buffer[epdrv->bufsize - 1] = '\0';
1030 		}
1031 	}
1032 
1033 	return 0;
1034 }
1035 
1036 /**
1037  * early_platform_add_devices - adds a number of early platform devices
1038  * @devs: array of early platform devices to add
1039  * @num: number of early platform devices in array
1040  *
1041  * Used by early architecture code to register early platform devices and
1042  * their platform data.
1043  */
1044 void __init early_platform_add_devices(struct platform_device **devs, int num)
1045 {
1046 	struct device *dev;
1047 	int i;
1048 
1049 	/* simply add the devices to list */
1050 	for (i = 0; i < num; i++) {
1051 		dev = &devs[i]->dev;
1052 
1053 		if (!dev->devres_head.next) {
1054 			INIT_LIST_HEAD(&dev->devres_head);
1055 			list_add_tail(&dev->devres_head,
1056 				      &early_platform_device_list);
1057 		}
1058 	}
1059 }
1060 
1061 /**
1062  * early_platform_driver_register_all - register early platform drivers
1063  * @class_str: string to identify early platform driver class
1064  *
1065  * Used by architecture code to register all early platform drivers
1066  * for a certain class. If omitted then only early platform drivers
1067  * with matching kernel command line class parameters will be registered.
1068  */
1069 void __init early_platform_driver_register_all(char *class_str)
1070 {
1071 	/* The "class_str" parameter may or may not be present on the kernel
1072 	 * command line. If it is present then there may be more than one
1073 	 * matching parameter.
1074 	 *
1075 	 * Since we register our early platform drivers using early_param()
1076 	 * we need to make sure that they also get registered in the case
1077 	 * when the parameter is missing from the kernel command line.
1078 	 *
1079 	 * We use parse_early_options() to make sure the early_param() gets
1080 	 * called at least once. The early_param() may be called more than
1081 	 * once since the name of the preferred device may be specified on
1082 	 * the kernel command line. early_platform_driver_register() handles
1083 	 * this case for us.
1084 	 */
1085 	parse_early_options(class_str);
1086 }
1087 
1088 /**
1089  * early_platform_match - find early platform device matching driver
1090  * @epdrv: early platform driver structure
1091  * @id: id to match against
1092  */
1093 static  __init struct platform_device *
1094 early_platform_match(struct early_platform_driver *epdrv, int id)
1095 {
1096 	struct platform_device *pd;
1097 
1098 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1099 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1100 			if (pd->id == id)
1101 				return pd;
1102 
1103 	return NULL;
1104 }
1105 
1106 /**
1107  * early_platform_left - check if early platform driver has matching devices
1108  * @epdrv: early platform driver structure
1109  * @id: return true if id or above exists
1110  */
1111 static  __init int early_platform_left(struct early_platform_driver *epdrv,
1112 				       int id)
1113 {
1114 	struct platform_device *pd;
1115 
1116 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1117 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1118 			if (pd->id >= id)
1119 				return 1;
1120 
1121 	return 0;
1122 }
1123 
1124 /**
1125  * early_platform_driver_probe_id - probe drivers matching class_str and id
1126  * @class_str: string to identify early platform driver class
1127  * @id: id to match against
1128  * @nr_probe: number of platform devices to successfully probe before exiting
1129  */
1130 static int __init early_platform_driver_probe_id(char *class_str,
1131 						 int id,
1132 						 int nr_probe)
1133 {
1134 	struct early_platform_driver *epdrv;
1135 	struct platform_device *match;
1136 	int match_id;
1137 	int n = 0;
1138 	int left = 0;
1139 
1140 	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1141 		/* only use drivers matching our class_str */
1142 		if (strcmp(class_str, epdrv->class_str))
1143 			continue;
1144 
1145 		if (id == -2) {
1146 			match_id = epdrv->requested_id;
1147 			left = 1;
1148 
1149 		} else {
1150 			match_id = id;
1151 			left += early_platform_left(epdrv, id);
1152 
1153 			/* skip requested id */
1154 			switch (epdrv->requested_id) {
1155 			case EARLY_PLATFORM_ID_ERROR:
1156 			case EARLY_PLATFORM_ID_UNSET:
1157 				break;
1158 			default:
1159 				if (epdrv->requested_id == id)
1160 					match_id = EARLY_PLATFORM_ID_UNSET;
1161 			}
1162 		}
1163 
1164 		switch (match_id) {
1165 		case EARLY_PLATFORM_ID_ERROR:
1166 			pr_warning("%s: unable to parse %s parameter\n",
1167 				   class_str, epdrv->pdrv->driver.name);
1168 			/* fall-through */
1169 		case EARLY_PLATFORM_ID_UNSET:
1170 			match = NULL;
1171 			break;
1172 		default:
1173 			match = early_platform_match(epdrv, match_id);
1174 		}
1175 
1176 		if (match) {
1177 			/*
1178 			 * Set up a sensible init_name to enable
1179 			 * dev_name() and others to be used before the
1180 			 * rest of the driver core is initialized.
1181 			 */
1182 			if (!match->dev.init_name && slab_is_available()) {
1183 				if (match->id != -1)
1184 					match->dev.init_name =
1185 						kasprintf(GFP_KERNEL, "%s.%d",
1186 							  match->name,
1187 							  match->id);
1188 				else
1189 					match->dev.init_name =
1190 						kasprintf(GFP_KERNEL, "%s",
1191 							  match->name);
1192 
1193 				if (!match->dev.init_name)
1194 					return -ENOMEM;
1195 			}
1196 
1197 			if (epdrv->pdrv->probe(match))
1198 				pr_warning("%s: unable to probe %s early.\n",
1199 					   class_str, match->name);
1200 			else
1201 				n++;
1202 		}
1203 
1204 		if (n >= nr_probe)
1205 			break;
1206 	}
1207 
1208 	if (left)
1209 		return n;
1210 	else
1211 		return -ENODEV;
1212 }
1213 
1214 /**
1215  * early_platform_driver_probe - probe a class of registered drivers
1216  * @class_str: string to identify early platform driver class
1217  * @nr_probe: number of platform devices to successfully probe before exiting
1218  * @user_only: only probe user specified early platform devices
1219  *
1220  * Used by architecture code to probe registered early platform drivers
1221  * within a certain class. For probe to happen a registered early platform
1222  * device matching a registered early platform driver is needed.
1223  */
1224 int __init early_platform_driver_probe(char *class_str,
1225 				       int nr_probe,
1226 				       int user_only)
1227 {
1228 	int k, n, i;
1229 
1230 	n = 0;
1231 	for (i = -2; n < nr_probe; i++) {
1232 		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1233 
1234 		if (k < 0)
1235 			break;
1236 
1237 		n += k;
1238 
1239 		if (user_only)
1240 			break;
1241 	}
1242 
1243 	return n;
1244 }
1245 
1246 /**
1247  * early_platform_cleanup - clean up early platform code
1248  */
1249 void __init early_platform_cleanup(void)
1250 {
1251 	struct platform_device *pd, *pd2;
1252 
1253 	/* clean up the devres list used to chain devices */
1254 	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1255 				 dev.devres_head) {
1256 		list_del(&pd->dev.devres_head);
1257 		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1258 	}
1259 }
1260 
1261