xref: /linux-6.15/drivers/base/platform.c (revision 71ccc212)
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  * platform_get_resource - get a resource for a device
36  * @dev: platform device
37  * @type: resource type
38  * @num: resource index
39  */
40 struct resource *platform_get_resource(struct platform_device *dev,
41 				       unsigned int type, unsigned int num)
42 {
43 	int i;
44 
45 	for (i = 0; i < dev->num_resources; i++) {
46 		struct resource *r = &dev->resource[i];
47 
48 		if (type == resource_type(r) && num-- == 0)
49 			return r;
50 	}
51 	return NULL;
52 }
53 EXPORT_SYMBOL_GPL(platform_get_resource);
54 
55 /**
56  * platform_get_irq - get an IRQ for a device
57  * @dev: platform device
58  * @num: IRQ number index
59  */
60 int platform_get_irq(struct platform_device *dev, unsigned int num)
61 {
62 	struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);
63 
64 	return r ? r->start : -ENXIO;
65 }
66 EXPORT_SYMBOL_GPL(platform_get_irq);
67 
68 /**
69  * platform_get_resource_byname - get a resource for a device by name
70  * @dev: platform device
71  * @type: resource type
72  * @name: resource name
73  */
74 struct resource *platform_get_resource_byname(struct platform_device *dev,
75 					      unsigned int type,
76 					      const char *name)
77 {
78 	int i;
79 
80 	for (i = 0; i < dev->num_resources; i++) {
81 		struct resource *r = &dev->resource[i];
82 
83 		if (type == resource_type(r) && !strcmp(r->name, name))
84 			return r;
85 	}
86 	return NULL;
87 }
88 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
89 
90 /**
91  * platform_get_irq - get an IRQ for a device
92  * @dev: platform device
93  * @name: IRQ name
94  */
95 int platform_get_irq_byname(struct platform_device *dev, const char *name)
96 {
97 	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
98 							  name);
99 
100 	return r ? r->start : -ENXIO;
101 }
102 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
103 
104 /**
105  * platform_add_devices - add a numbers of platform devices
106  * @devs: array of platform devices to add
107  * @num: number of platform devices in array
108  */
109 int platform_add_devices(struct platform_device **devs, int num)
110 {
111 	int i, ret = 0;
112 
113 	for (i = 0; i < num; i++) {
114 		ret = platform_device_register(devs[i]);
115 		if (ret) {
116 			while (--i >= 0)
117 				platform_device_unregister(devs[i]);
118 			break;
119 		}
120 	}
121 
122 	return ret;
123 }
124 EXPORT_SYMBOL_GPL(platform_add_devices);
125 
126 struct platform_object {
127 	struct platform_device pdev;
128 	char name[1];
129 };
130 
131 /**
132  * platform_device_put - destroy a platform device
133  * @pdev: platform device to free
134  *
135  * Free all memory associated with a platform device.  This function must
136  * _only_ be externally called in error cases.  All other usage is a bug.
137  */
138 void platform_device_put(struct platform_device *pdev)
139 {
140 	if (pdev)
141 		put_device(&pdev->dev);
142 }
143 EXPORT_SYMBOL_GPL(platform_device_put);
144 
145 static void platform_device_release(struct device *dev)
146 {
147 	struct platform_object *pa = container_of(dev, struct platform_object,
148 						  pdev.dev);
149 
150 	kfree(pa->pdev.dev.platform_data);
151 	kfree(pa->pdev.resource);
152 	kfree(pa);
153 }
154 
155 /**
156  * platform_device_alloc - create a platform device
157  * @name: base name of the device we're adding
158  * @id: instance id
159  *
160  * Create a platform device object which can have other objects attached
161  * to it, and which will have attached objects freed when it is released.
162  */
163 struct platform_device *platform_device_alloc(const char *name, int id)
164 {
165 	struct platform_object *pa;
166 
167 	pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
168 	if (pa) {
169 		strcpy(pa->name, name);
170 		pa->pdev.name = pa->name;
171 		pa->pdev.id = id;
172 		device_initialize(&pa->pdev.dev);
173 		pa->pdev.dev.release = platform_device_release;
174 	}
175 
176 	return pa ? &pa->pdev : NULL;
177 }
178 EXPORT_SYMBOL_GPL(platform_device_alloc);
179 
180 /**
181  * platform_device_add_resources - add resources to a platform device
182  * @pdev: platform device allocated by platform_device_alloc to add resources to
183  * @res: set of resources that needs to be allocated for the device
184  * @num: number of resources
185  *
186  * Add a copy of the resources to the platform device.  The memory
187  * associated with the resources will be freed when the platform device is
188  * released.
189  */
190 int platform_device_add_resources(struct platform_device *pdev,
191 				  const struct resource *res, unsigned int num)
192 {
193 	struct resource *r;
194 
195 	if (!res)
196 		return 0;
197 
198 	r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
199 	if (r) {
200 		pdev->resource = r;
201 		pdev->num_resources = num;
202 		return 0;
203 	}
204 	return -ENOMEM;
205 }
206 EXPORT_SYMBOL_GPL(platform_device_add_resources);
207 
208 /**
209  * platform_device_add_data - add platform-specific data to a platform device
210  * @pdev: platform device allocated by platform_device_alloc to add resources to
211  * @data: platform specific data for this platform device
212  * @size: size of platform specific data
213  *
214  * Add a copy of platform specific data to the platform device's
215  * platform_data pointer.  The memory associated with the platform data
216  * will be freed when the platform device is released.
217  */
218 int platform_device_add_data(struct platform_device *pdev, const void *data,
219 			     size_t size)
220 {
221 	void *d;
222 
223 	if (!data)
224 		return 0;
225 
226 	d = kmemdup(data, size, GFP_KERNEL);
227 	if (d) {
228 		pdev->dev.platform_data = d;
229 		return 0;
230 	}
231 	return -ENOMEM;
232 }
233 EXPORT_SYMBOL_GPL(platform_device_add_data);
234 
235 /**
236  * platform_device_add - add a platform device to device hierarchy
237  * @pdev: platform device we're adding
238  *
239  * This is part 2 of platform_device_register(), though may be called
240  * separately _iff_ pdev was allocated by platform_device_alloc().
241  */
242 int platform_device_add(struct platform_device *pdev)
243 {
244 	int i, ret = 0;
245 
246 	if (!pdev)
247 		return -EINVAL;
248 
249 	if (!pdev->dev.parent)
250 		pdev->dev.parent = &platform_bus;
251 
252 	pdev->dev.bus = &platform_bus_type;
253 
254 	if (pdev->id != -1)
255 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
256 	else
257 		dev_set_name(&pdev->dev, "%s", pdev->name);
258 
259 	for (i = 0; i < pdev->num_resources; i++) {
260 		struct resource *p, *r = &pdev->resource[i];
261 
262 		if (r->name == NULL)
263 			r->name = dev_name(&pdev->dev);
264 
265 		p = r->parent;
266 		if (!p) {
267 			if (resource_type(r) == IORESOURCE_MEM)
268 				p = &iomem_resource;
269 			else if (resource_type(r) == IORESOURCE_IO)
270 				p = &ioport_resource;
271 		}
272 
273 		if (p && insert_resource(p, r)) {
274 			printk(KERN_ERR
275 			       "%s: failed to claim resource %d\n",
276 			       dev_name(&pdev->dev), i);
277 			ret = -EBUSY;
278 			goto failed;
279 		}
280 	}
281 
282 	pr_debug("Registering platform device '%s'. Parent at %s\n",
283 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
284 
285 	ret = device_add(&pdev->dev);
286 	if (ret == 0)
287 		return ret;
288 
289  failed:
290 	while (--i >= 0) {
291 		struct resource *r = &pdev->resource[i];
292 		unsigned long type = resource_type(r);
293 
294 		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
295 			release_resource(r);
296 	}
297 
298 	return ret;
299 }
300 EXPORT_SYMBOL_GPL(platform_device_add);
301 
302 /**
303  * platform_device_del - remove a platform-level device
304  * @pdev: platform device we're removing
305  *
306  * Note that this function will also release all memory- and port-based
307  * resources owned by the device (@dev->resource).  This function must
308  * _only_ be externally called in error cases.  All other usage is a bug.
309  */
310 void platform_device_del(struct platform_device *pdev)
311 {
312 	int i;
313 
314 	if (pdev) {
315 		device_del(&pdev->dev);
316 
317 		for (i = 0; i < pdev->num_resources; i++) {
318 			struct resource *r = &pdev->resource[i];
319 			unsigned long type = resource_type(r);
320 
321 			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
322 				release_resource(r);
323 		}
324 	}
325 }
326 EXPORT_SYMBOL_GPL(platform_device_del);
327 
328 /**
329  * platform_device_register - add a platform-level device
330  * @pdev: platform device we're adding
331  */
332 int platform_device_register(struct platform_device *pdev)
333 {
334 	device_initialize(&pdev->dev);
335 	return platform_device_add(pdev);
336 }
337 EXPORT_SYMBOL_GPL(platform_device_register);
338 
339 /**
340  * platform_device_unregister - unregister a platform-level device
341  * @pdev: platform device we're unregistering
342  *
343  * Unregistration is done in 2 steps. First we release all resources
344  * and remove it from the subsystem, then we drop reference count by
345  * calling platform_device_put().
346  */
347 void platform_device_unregister(struct platform_device *pdev)
348 {
349 	platform_device_del(pdev);
350 	platform_device_put(pdev);
351 }
352 EXPORT_SYMBOL_GPL(platform_device_unregister);
353 
354 /**
355  * platform_device_register_resndata - add a platform-level device with
356  * resources and platform-specific data
357  *
358  * @parent: parent device for the device we're adding
359  * @name: base name of the device we're adding
360  * @id: instance id
361  * @res: set of resources that needs to be allocated for the device
362  * @num: number of resources
363  * @data: platform specific data for this platform device
364  * @size: size of platform specific data
365  *
366  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
367  */
368 struct platform_device *__init_or_module platform_device_register_resndata(
369 		struct device *parent,
370 		const char *name, int id,
371 		const struct resource *res, unsigned int num,
372 		const void *data, size_t size)
373 {
374 	int ret = -ENOMEM;
375 	struct platform_device *pdev;
376 
377 	pdev = platform_device_alloc(name, id);
378 	if (!pdev)
379 		goto err;
380 
381 	pdev->dev.parent = parent;
382 
383 	ret = platform_device_add_resources(pdev, res, num);
384 	if (ret)
385 		goto err;
386 
387 	ret = platform_device_add_data(pdev, data, size);
388 	if (ret)
389 		goto err;
390 
391 	ret = platform_device_add(pdev);
392 	if (ret) {
393 err:
394 		platform_device_put(pdev);
395 		return ERR_PTR(ret);
396 	}
397 
398 	return pdev;
399 }
400 EXPORT_SYMBOL_GPL(platform_device_register_resndata);
401 
402 static int platform_drv_probe(struct device *_dev)
403 {
404 	struct platform_driver *drv = to_platform_driver(_dev->driver);
405 	struct platform_device *dev = to_platform_device(_dev);
406 
407 	return drv->probe(dev);
408 }
409 
410 static int platform_drv_probe_fail(struct device *_dev)
411 {
412 	return -ENXIO;
413 }
414 
415 static int platform_drv_remove(struct device *_dev)
416 {
417 	struct platform_driver *drv = to_platform_driver(_dev->driver);
418 	struct platform_device *dev = to_platform_device(_dev);
419 
420 	return drv->remove(dev);
421 }
422 
423 static void platform_drv_shutdown(struct device *_dev)
424 {
425 	struct platform_driver *drv = to_platform_driver(_dev->driver);
426 	struct platform_device *dev = to_platform_device(_dev);
427 
428 	drv->shutdown(dev);
429 }
430 
431 /**
432  * platform_driver_register - register a driver for platform-level devices
433  * @drv: platform driver structure
434  */
435 int platform_driver_register(struct platform_driver *drv)
436 {
437 	drv->driver.bus = &platform_bus_type;
438 	if (drv->probe)
439 		drv->driver.probe = platform_drv_probe;
440 	if (drv->remove)
441 		drv->driver.remove = platform_drv_remove;
442 	if (drv->shutdown)
443 		drv->driver.shutdown = platform_drv_shutdown;
444 
445 	return driver_register(&drv->driver);
446 }
447 EXPORT_SYMBOL_GPL(platform_driver_register);
448 
449 /**
450  * platform_driver_unregister - unregister a driver for platform-level devices
451  * @drv: platform driver structure
452  */
453 void platform_driver_unregister(struct platform_driver *drv)
454 {
455 	driver_unregister(&drv->driver);
456 }
457 EXPORT_SYMBOL_GPL(platform_driver_unregister);
458 
459 /**
460  * platform_driver_probe - register driver for non-hotpluggable device
461  * @drv: platform driver structure
462  * @probe: the driver probe routine, probably from an __init section
463  *
464  * Use this instead of platform_driver_register() when you know the device
465  * is not hotpluggable and has already been registered, and you want to
466  * remove its run-once probe() infrastructure from memory after the driver
467  * has bound to the device.
468  *
469  * One typical use for this would be with drivers for controllers integrated
470  * into system-on-chip processors, where the controller devices have been
471  * configured as part of board setup.
472  *
473  * Returns zero if the driver registered and bound to a device, else returns
474  * a negative error code and with the driver not registered.
475  */
476 int __init_or_module platform_driver_probe(struct platform_driver *drv,
477 		int (*probe)(struct platform_device *))
478 {
479 	int retval, code;
480 
481 	/* make sure driver won't have bind/unbind attributes */
482 	drv->driver.suppress_bind_attrs = true;
483 
484 	/* temporary section violation during probe() */
485 	drv->probe = probe;
486 	retval = code = platform_driver_register(drv);
487 
488 	/*
489 	 * Fixup that section violation, being paranoid about code scanning
490 	 * the list of drivers in order to probe new devices.  Check to see
491 	 * if the probe was successful, and make sure any forced probes of
492 	 * new devices fail.
493 	 */
494 	spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
495 	drv->probe = NULL;
496 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
497 		retval = -ENODEV;
498 	drv->driver.probe = platform_drv_probe_fail;
499 	spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
500 
501 	if (code != retval)
502 		platform_driver_unregister(drv);
503 	return retval;
504 }
505 EXPORT_SYMBOL_GPL(platform_driver_probe);
506 
507 /**
508  * platform_create_bundle - register driver and create corresponding device
509  * @driver: platform driver structure
510  * @probe: the driver probe routine, probably from an __init section
511  * @res: set of resources that needs to be allocated for the device
512  * @n_res: number of resources
513  * @data: platform specific data for this platform device
514  * @size: size of platform specific data
515  *
516  * Use this in legacy-style modules that probe hardware directly and
517  * register a single platform device and corresponding platform driver.
518  *
519  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
520  */
521 struct platform_device * __init_or_module platform_create_bundle(
522 			struct platform_driver *driver,
523 			int (*probe)(struct platform_device *),
524 			struct resource *res, unsigned int n_res,
525 			const void *data, size_t size)
526 {
527 	struct platform_device *pdev;
528 	int error;
529 
530 	pdev = platform_device_alloc(driver->driver.name, -1);
531 	if (!pdev) {
532 		error = -ENOMEM;
533 		goto err_out;
534 	}
535 
536 	error = platform_device_add_resources(pdev, res, n_res);
537 	if (error)
538 		goto err_pdev_put;
539 
540 	error = platform_device_add_data(pdev, data, size);
541 	if (error)
542 		goto err_pdev_put;
543 
544 	error = platform_device_add(pdev);
545 	if (error)
546 		goto err_pdev_put;
547 
548 	error = platform_driver_probe(driver, probe);
549 	if (error)
550 		goto err_pdev_del;
551 
552 	return pdev;
553 
554 err_pdev_del:
555 	platform_device_del(pdev);
556 err_pdev_put:
557 	platform_device_put(pdev);
558 err_out:
559 	return ERR_PTR(error);
560 }
561 EXPORT_SYMBOL_GPL(platform_create_bundle);
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 	int rc;
587 
588 	/* Some devices have extra OF data and an OF-style MODALIAS */
589 	rc = of_device_uevent(dev,env);
590 	if (rc != -ENODEV)
591 		return rc;
592 
593 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
594 		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);
595 	return 0;
596 }
597 
598 static const struct platform_device_id *platform_match_id(
599 			const struct platform_device_id *id,
600 			struct platform_device *pdev)
601 {
602 	while (id->name[0]) {
603 		if (strcmp(pdev->name, id->name) == 0) {
604 			pdev->id_entry = id;
605 			return id;
606 		}
607 		id++;
608 	}
609 	return NULL;
610 }
611 
612 /**
613  * platform_match - bind platform device to platform driver.
614  * @dev: device.
615  * @drv: driver.
616  *
617  * Platform device IDs are assumed to be encoded like this:
618  * "<name><instance>", where <name> is a short description of the type of
619  * device, like "pci" or "floppy", and <instance> is the enumerated
620  * instance of the device, like '0' or '42'.  Driver IDs are simply
621  * "<name>".  So, extract the <name> from the platform_device structure,
622  * and compare it against the name of the driver. Return whether they match
623  * or not.
624  */
625 static int platform_match(struct device *dev, struct device_driver *drv)
626 {
627 	struct platform_device *pdev = to_platform_device(dev);
628 	struct platform_driver *pdrv = to_platform_driver(drv);
629 
630 	/* Attempt an OF style match first */
631 	if (of_driver_match_device(dev, drv))
632 		return 1;
633 
634 	/* Then try to match against the id table */
635 	if (pdrv->id_table)
636 		return platform_match_id(pdrv->id_table, pdev) != NULL;
637 
638 	/* fall-back to driver name match */
639 	return (strcmp(pdev->name, drv->name) == 0);
640 }
641 
642 #ifdef CONFIG_PM_SLEEP
643 
644 static int platform_legacy_suspend(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)
651 		ret = pdrv->suspend(pdev, mesg);
652 
653 	return ret;
654 }
655 
656 static int platform_legacy_resume(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)
663 		ret = pdrv->resume(pdev);
664 
665 	return ret;
666 }
667 
668 static int platform_pm_prepare(struct device *dev)
669 {
670 	struct device_driver *drv = dev->driver;
671 	int ret = 0;
672 
673 	if (drv && drv->pm && drv->pm->prepare)
674 		ret = drv->pm->prepare(dev);
675 
676 	return ret;
677 }
678 
679 static void platform_pm_complete(struct device *dev)
680 {
681 	struct device_driver *drv = dev->driver;
682 
683 	if (drv && drv->pm && drv->pm->complete)
684 		drv->pm->complete(dev);
685 }
686 
687 #else /* !CONFIG_PM_SLEEP */
688 
689 #define platform_pm_prepare		NULL
690 #define platform_pm_complete		NULL
691 
692 #endif /* !CONFIG_PM_SLEEP */
693 
694 #ifdef CONFIG_SUSPEND
695 
696 int __weak platform_pm_suspend(struct device *dev)
697 {
698 	struct device_driver *drv = dev->driver;
699 	int ret = 0;
700 
701 	if (!drv)
702 		return 0;
703 
704 	if (drv->pm) {
705 		if (drv->pm->suspend)
706 			ret = drv->pm->suspend(dev);
707 	} else {
708 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
709 	}
710 
711 	return ret;
712 }
713 
714 int __weak platform_pm_suspend_noirq(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_noirq)
724 			ret = drv->pm->suspend_noirq(dev);
725 	}
726 
727 	return ret;
728 }
729 
730 int __weak platform_pm_resume(struct device *dev)
731 {
732 	struct device_driver *drv = dev->driver;
733 	int ret = 0;
734 
735 	if (!drv)
736 		return 0;
737 
738 	if (drv->pm) {
739 		if (drv->pm->resume)
740 			ret = drv->pm->resume(dev);
741 	} else {
742 		ret = platform_legacy_resume(dev);
743 	}
744 
745 	return ret;
746 }
747 
748 int __weak platform_pm_resume_noirq(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_noirq)
758 			ret = drv->pm->resume_noirq(dev);
759 	}
760 
761 	return ret;
762 }
763 
764 #else /* !CONFIG_SUSPEND */
765 
766 #define platform_pm_suspend		NULL
767 #define platform_pm_resume		NULL
768 #define platform_pm_suspend_noirq	NULL
769 #define platform_pm_resume_noirq	NULL
770 
771 #endif /* !CONFIG_SUSPEND */
772 
773 #ifdef CONFIG_HIBERNATION
774 
775 static int platform_pm_freeze(struct device *dev)
776 {
777 	struct device_driver *drv = dev->driver;
778 	int ret = 0;
779 
780 	if (!drv)
781 		return 0;
782 
783 	if (drv->pm) {
784 		if (drv->pm->freeze)
785 			ret = drv->pm->freeze(dev);
786 	} else {
787 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
788 	}
789 
790 	return ret;
791 }
792 
793 static int platform_pm_freeze_noirq(struct device *dev)
794 {
795 	struct device_driver *drv = dev->driver;
796 	int ret = 0;
797 
798 	if (!drv)
799 		return 0;
800 
801 	if (drv->pm) {
802 		if (drv->pm->freeze_noirq)
803 			ret = drv->pm->freeze_noirq(dev);
804 	}
805 
806 	return ret;
807 }
808 
809 static int platform_pm_thaw(struct device *dev)
810 {
811 	struct device_driver *drv = dev->driver;
812 	int ret = 0;
813 
814 	if (!drv)
815 		return 0;
816 
817 	if (drv->pm) {
818 		if (drv->pm->thaw)
819 			ret = drv->pm->thaw(dev);
820 	} else {
821 		ret = platform_legacy_resume(dev);
822 	}
823 
824 	return ret;
825 }
826 
827 static int platform_pm_thaw_noirq(struct device *dev)
828 {
829 	struct device_driver *drv = dev->driver;
830 	int ret = 0;
831 
832 	if (!drv)
833 		return 0;
834 
835 	if (drv->pm) {
836 		if (drv->pm->thaw_noirq)
837 			ret = drv->pm->thaw_noirq(dev);
838 	}
839 
840 	return ret;
841 }
842 
843 static int platform_pm_poweroff(struct device *dev)
844 {
845 	struct device_driver *drv = dev->driver;
846 	int ret = 0;
847 
848 	if (!drv)
849 		return 0;
850 
851 	if (drv->pm) {
852 		if (drv->pm->poweroff)
853 			ret = drv->pm->poweroff(dev);
854 	} else {
855 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
856 	}
857 
858 	return ret;
859 }
860 
861 static int platform_pm_poweroff_noirq(struct device *dev)
862 {
863 	struct device_driver *drv = dev->driver;
864 	int ret = 0;
865 
866 	if (!drv)
867 		return 0;
868 
869 	if (drv->pm) {
870 		if (drv->pm->poweroff_noirq)
871 			ret = drv->pm->poweroff_noirq(dev);
872 	}
873 
874 	return ret;
875 }
876 
877 static int platform_pm_restore(struct device *dev)
878 {
879 	struct device_driver *drv = dev->driver;
880 	int ret = 0;
881 
882 	if (!drv)
883 		return 0;
884 
885 	if (drv->pm) {
886 		if (drv->pm->restore)
887 			ret = drv->pm->restore(dev);
888 	} else {
889 		ret = platform_legacy_resume(dev);
890 	}
891 
892 	return ret;
893 }
894 
895 static int platform_pm_restore_noirq(struct device *dev)
896 {
897 	struct device_driver *drv = dev->driver;
898 	int ret = 0;
899 
900 	if (!drv)
901 		return 0;
902 
903 	if (drv->pm) {
904 		if (drv->pm->restore_noirq)
905 			ret = drv->pm->restore_noirq(dev);
906 	}
907 
908 	return ret;
909 }
910 
911 #else /* !CONFIG_HIBERNATION */
912 
913 #define platform_pm_freeze		NULL
914 #define platform_pm_thaw		NULL
915 #define platform_pm_poweroff		NULL
916 #define platform_pm_restore		NULL
917 #define platform_pm_freeze_noirq	NULL
918 #define platform_pm_thaw_noirq		NULL
919 #define platform_pm_poweroff_noirq	NULL
920 #define platform_pm_restore_noirq	NULL
921 
922 #endif /* !CONFIG_HIBERNATION */
923 
924 #ifdef CONFIG_PM_RUNTIME
925 
926 int __weak platform_pm_runtime_suspend(struct device *dev)
927 {
928 	return pm_generic_runtime_suspend(dev);
929 };
930 
931 int __weak platform_pm_runtime_resume(struct device *dev)
932 {
933 	return pm_generic_runtime_resume(dev);
934 };
935 
936 int __weak platform_pm_runtime_idle(struct device *dev)
937 {
938 	return pm_generic_runtime_idle(dev);
939 };
940 
941 #else /* !CONFIG_PM_RUNTIME */
942 
943 #define platform_pm_runtime_suspend NULL
944 #define platform_pm_runtime_resume NULL
945 #define platform_pm_runtime_idle NULL
946 
947 #endif /* !CONFIG_PM_RUNTIME */
948 
949 static const struct dev_pm_ops platform_dev_pm_ops = {
950 	.prepare = platform_pm_prepare,
951 	.complete = platform_pm_complete,
952 	.suspend = platform_pm_suspend,
953 	.resume = platform_pm_resume,
954 	.freeze = platform_pm_freeze,
955 	.thaw = platform_pm_thaw,
956 	.poweroff = platform_pm_poweroff,
957 	.restore = platform_pm_restore,
958 	.suspend_noirq = platform_pm_suspend_noirq,
959 	.resume_noirq = platform_pm_resume_noirq,
960 	.freeze_noirq = platform_pm_freeze_noirq,
961 	.thaw_noirq = platform_pm_thaw_noirq,
962 	.poweroff_noirq = platform_pm_poweroff_noirq,
963 	.restore_noirq = platform_pm_restore_noirq,
964 	.runtime_suspend = platform_pm_runtime_suspend,
965 	.runtime_resume = platform_pm_runtime_resume,
966 	.runtime_idle = platform_pm_runtime_idle,
967 };
968 
969 struct bus_type platform_bus_type = {
970 	.name		= "platform",
971 	.dev_attrs	= platform_dev_attrs,
972 	.match		= platform_match,
973 	.uevent		= platform_uevent,
974 	.pm		= &platform_dev_pm_ops,
975 };
976 EXPORT_SYMBOL_GPL(platform_bus_type);
977 
978 /**
979  * platform_bus_get_pm_ops() - return pointer to busses dev_pm_ops
980  *
981  * This function can be used by platform code to get the current
982  * set of dev_pm_ops functions used by the platform_bus_type.
983  */
984 const struct dev_pm_ops * __init platform_bus_get_pm_ops(void)
985 {
986 	return platform_bus_type.pm;
987 }
988 
989 /**
990  * platform_bus_set_pm_ops() - update dev_pm_ops for the platform_bus_type
991  *
992  * @pm: pointer to new dev_pm_ops struct to be used for platform_bus_type
993  *
994  * Platform code can override the dev_pm_ops methods of
995  * platform_bus_type by using this function.  It is expected that
996  * platform code will first do a platform_bus_get_pm_ops(), then
997  * kmemdup it, then customize selected methods and pass a pointer to
998  * the new struct dev_pm_ops to this function.
999  *
1000  * Since platform-specific code is customizing methods for *all*
1001  * devices (not just platform-specific devices) it is expected that
1002  * any custom overrides of these functions will keep existing behavior
1003  * and simply extend it.  For example, any customization of the
1004  * runtime PM methods should continue to call the pm_generic_*
1005  * functions as the default ones do in addition to the
1006  * platform-specific behavior.
1007  */
1008 void __init platform_bus_set_pm_ops(const struct dev_pm_ops *pm)
1009 {
1010 	platform_bus_type.pm = pm;
1011 }
1012 
1013 int __init platform_bus_init(void)
1014 {
1015 	int error;
1016 
1017 	early_platform_cleanup();
1018 
1019 	error = device_register(&platform_bus);
1020 	if (error)
1021 		return error;
1022 	error =  bus_register(&platform_bus_type);
1023 	if (error)
1024 		device_unregister(&platform_bus);
1025 	return error;
1026 }
1027 
1028 #ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
1029 u64 dma_get_required_mask(struct device *dev)
1030 {
1031 	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
1032 	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
1033 	u64 mask;
1034 
1035 	if (!high_totalram) {
1036 		/* convert to mask just covering totalram */
1037 		low_totalram = (1 << (fls(low_totalram) - 1));
1038 		low_totalram += low_totalram - 1;
1039 		mask = low_totalram;
1040 	} else {
1041 		high_totalram = (1 << (fls(high_totalram) - 1));
1042 		high_totalram += high_totalram - 1;
1043 		mask = (((u64)high_totalram) << 32) + 0xffffffff;
1044 	}
1045 	return mask;
1046 }
1047 EXPORT_SYMBOL_GPL(dma_get_required_mask);
1048 #endif
1049 
1050 static __initdata LIST_HEAD(early_platform_driver_list);
1051 static __initdata LIST_HEAD(early_platform_device_list);
1052 
1053 /**
1054  * early_platform_driver_register - register early platform driver
1055  * @epdrv: early_platform driver structure
1056  * @buf: string passed from early_param()
1057  *
1058  * Helper function for early_platform_init() / early_platform_init_buffer()
1059  */
1060 int __init early_platform_driver_register(struct early_platform_driver *epdrv,
1061 					  char *buf)
1062 {
1063 	char *tmp;
1064 	int n;
1065 
1066 	/* Simply add the driver to the end of the global list.
1067 	 * Drivers will by default be put on the list in compiled-in order.
1068 	 */
1069 	if (!epdrv->list.next) {
1070 		INIT_LIST_HEAD(&epdrv->list);
1071 		list_add_tail(&epdrv->list, &early_platform_driver_list);
1072 	}
1073 
1074 	/* If the user has specified device then make sure the driver
1075 	 * gets prioritized. The driver of the last device specified on
1076 	 * command line will be put first on the list.
1077 	 */
1078 	n = strlen(epdrv->pdrv->driver.name);
1079 	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
1080 		list_move(&epdrv->list, &early_platform_driver_list);
1081 
1082 		/* Allow passing parameters after device name */
1083 		if (buf[n] == '\0' || buf[n] == ',')
1084 			epdrv->requested_id = -1;
1085 		else {
1086 			epdrv->requested_id = simple_strtoul(&buf[n + 1],
1087 							     &tmp, 10);
1088 
1089 			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
1090 				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
1091 				n = 0;
1092 			} else
1093 				n += strcspn(&buf[n + 1], ",") + 1;
1094 		}
1095 
1096 		if (buf[n] == ',')
1097 			n++;
1098 
1099 		if (epdrv->bufsize) {
1100 			memcpy(epdrv->buffer, &buf[n],
1101 			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
1102 			epdrv->buffer[epdrv->bufsize - 1] = '\0';
1103 		}
1104 	}
1105 
1106 	return 0;
1107 }
1108 
1109 /**
1110  * early_platform_add_devices - adds a number of early platform devices
1111  * @devs: array of early platform devices to add
1112  * @num: number of early platform devices in array
1113  *
1114  * Used by early architecture code to register early platform devices and
1115  * their platform data.
1116  */
1117 void __init early_platform_add_devices(struct platform_device **devs, int num)
1118 {
1119 	struct device *dev;
1120 	int i;
1121 
1122 	/* simply add the devices to list */
1123 	for (i = 0; i < num; i++) {
1124 		dev = &devs[i]->dev;
1125 
1126 		if (!dev->devres_head.next) {
1127 			INIT_LIST_HEAD(&dev->devres_head);
1128 			list_add_tail(&dev->devres_head,
1129 				      &early_platform_device_list);
1130 		}
1131 	}
1132 }
1133 
1134 /**
1135  * early_platform_driver_register_all - register early platform drivers
1136  * @class_str: string to identify early platform driver class
1137  *
1138  * Used by architecture code to register all early platform drivers
1139  * for a certain class. If omitted then only early platform drivers
1140  * with matching kernel command line class parameters will be registered.
1141  */
1142 void __init early_platform_driver_register_all(char *class_str)
1143 {
1144 	/* The "class_str" parameter may or may not be present on the kernel
1145 	 * command line. If it is present then there may be more than one
1146 	 * matching parameter.
1147 	 *
1148 	 * Since we register our early platform drivers using early_param()
1149 	 * we need to make sure that they also get registered in the case
1150 	 * when the parameter is missing from the kernel command line.
1151 	 *
1152 	 * We use parse_early_options() to make sure the early_param() gets
1153 	 * called at least once. The early_param() may be called more than
1154 	 * once since the name of the preferred device may be specified on
1155 	 * the kernel command line. early_platform_driver_register() handles
1156 	 * this case for us.
1157 	 */
1158 	parse_early_options(class_str);
1159 }
1160 
1161 /**
1162  * early_platform_match - find early platform device matching driver
1163  * @epdrv: early platform driver structure
1164  * @id: id to match against
1165  */
1166 static  __init struct platform_device *
1167 early_platform_match(struct early_platform_driver *epdrv, int id)
1168 {
1169 	struct platform_device *pd;
1170 
1171 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1172 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1173 			if (pd->id == id)
1174 				return pd;
1175 
1176 	return NULL;
1177 }
1178 
1179 /**
1180  * early_platform_left - check if early platform driver has matching devices
1181  * @epdrv: early platform driver structure
1182  * @id: return true if id or above exists
1183  */
1184 static  __init int early_platform_left(struct early_platform_driver *epdrv,
1185 				       int id)
1186 {
1187 	struct platform_device *pd;
1188 
1189 	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
1190 		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
1191 			if (pd->id >= id)
1192 				return 1;
1193 
1194 	return 0;
1195 }
1196 
1197 /**
1198  * early_platform_driver_probe_id - probe drivers matching class_str and id
1199  * @class_str: string to identify early platform driver class
1200  * @id: id to match against
1201  * @nr_probe: number of platform devices to successfully probe before exiting
1202  */
1203 static int __init early_platform_driver_probe_id(char *class_str,
1204 						 int id,
1205 						 int nr_probe)
1206 {
1207 	struct early_platform_driver *epdrv;
1208 	struct platform_device *match;
1209 	int match_id;
1210 	int n = 0;
1211 	int left = 0;
1212 
1213 	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
1214 		/* only use drivers matching our class_str */
1215 		if (strcmp(class_str, epdrv->class_str))
1216 			continue;
1217 
1218 		if (id == -2) {
1219 			match_id = epdrv->requested_id;
1220 			left = 1;
1221 
1222 		} else {
1223 			match_id = id;
1224 			left += early_platform_left(epdrv, id);
1225 
1226 			/* skip requested id */
1227 			switch (epdrv->requested_id) {
1228 			case EARLY_PLATFORM_ID_ERROR:
1229 			case EARLY_PLATFORM_ID_UNSET:
1230 				break;
1231 			default:
1232 				if (epdrv->requested_id == id)
1233 					match_id = EARLY_PLATFORM_ID_UNSET;
1234 			}
1235 		}
1236 
1237 		switch (match_id) {
1238 		case EARLY_PLATFORM_ID_ERROR:
1239 			pr_warning("%s: unable to parse %s parameter\n",
1240 				   class_str, epdrv->pdrv->driver.name);
1241 			/* fall-through */
1242 		case EARLY_PLATFORM_ID_UNSET:
1243 			match = NULL;
1244 			break;
1245 		default:
1246 			match = early_platform_match(epdrv, match_id);
1247 		}
1248 
1249 		if (match) {
1250 			/*
1251 			 * Set up a sensible init_name to enable
1252 			 * dev_name() and others to be used before the
1253 			 * rest of the driver core is initialized.
1254 			 */
1255 			if (!match->dev.init_name && slab_is_available()) {
1256 				if (match->id != -1)
1257 					match->dev.init_name =
1258 						kasprintf(GFP_KERNEL, "%s.%d",
1259 							  match->name,
1260 							  match->id);
1261 				else
1262 					match->dev.init_name =
1263 						kasprintf(GFP_KERNEL, "%s",
1264 							  match->name);
1265 
1266 				if (!match->dev.init_name)
1267 					return -ENOMEM;
1268 			}
1269 
1270 			if (epdrv->pdrv->probe(match))
1271 				pr_warning("%s: unable to probe %s early.\n",
1272 					   class_str, match->name);
1273 			else
1274 				n++;
1275 		}
1276 
1277 		if (n >= nr_probe)
1278 			break;
1279 	}
1280 
1281 	if (left)
1282 		return n;
1283 	else
1284 		return -ENODEV;
1285 }
1286 
1287 /**
1288  * early_platform_driver_probe - probe a class of registered drivers
1289  * @class_str: string to identify early platform driver class
1290  * @nr_probe: number of platform devices to successfully probe before exiting
1291  * @user_only: only probe user specified early platform devices
1292  *
1293  * Used by architecture code to probe registered early platform drivers
1294  * within a certain class. For probe to happen a registered early platform
1295  * device matching a registered early platform driver is needed.
1296  */
1297 int __init early_platform_driver_probe(char *class_str,
1298 				       int nr_probe,
1299 				       int user_only)
1300 {
1301 	int k, n, i;
1302 
1303 	n = 0;
1304 	for (i = -2; n < nr_probe; i++) {
1305 		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);
1306 
1307 		if (k < 0)
1308 			break;
1309 
1310 		n += k;
1311 
1312 		if (user_only)
1313 			break;
1314 	}
1315 
1316 	return n;
1317 }
1318 
1319 /**
1320  * early_platform_cleanup - clean up early platform code
1321  */
1322 void __init early_platform_cleanup(void)
1323 {
1324 	struct platform_device *pd, *pd2;
1325 
1326 	/* clean up the devres list used to chain devices */
1327 	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
1328 				 dev.devres_head) {
1329 		list_del(&pd->dev.devres_head);
1330 		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
1331 	}
1332 }
1333 
1334