xref: /linux-6.15/drivers/base/platform.c (revision b8fecfdf)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * platform.c - platform 'pseudo' bus for legacy devices
4  *
5  * Copyright (c) 2002-3 Patrick Mochel
6  * Copyright (c) 2002-3 Open Source Development Labs
7  *
8  * Please see Documentation/driver-api/driver-model/platform.rst for more
9  * information.
10  */
11 
12 #include <linux/string.h>
13 #include <linux/platform_device.h>
14 #include <linux/of_device.h>
15 #include <linux/of_irq.h>
16 #include <linux/module.h>
17 #include <linux/init.h>
18 #include <linux/interrupt.h>
19 #include <linux/ioport.h>
20 #include <linux/dma-mapping.h>
21 #include <linux/memblock.h>
22 #include <linux/err.h>
23 #include <linux/slab.h>
24 #include <linux/pm_runtime.h>
25 #include <linux/pm_domain.h>
26 #include <linux/idr.h>
27 #include <linux/acpi.h>
28 #include <linux/clk/clk-conf.h>
29 #include <linux/limits.h>
30 #include <linux/property.h>
31 #include <linux/kmemleak.h>
32 #include <linux/types.h>
33 
34 #include "base.h"
35 #include "power/power.h"
36 
37 /* For automatically allocated device IDs */
38 static DEFINE_IDA(platform_devid_ida);
39 
40 struct device platform_bus = {
41 	.init_name	= "platform",
42 };
43 EXPORT_SYMBOL_GPL(platform_bus);
44 
45 /**
46  * platform_get_resource - get a resource for a device
47  * @dev: platform device
48  * @type: resource type
49  * @num: resource index
50  *
51  * Return: a pointer to the resource or NULL on failure.
52  */
53 struct resource *platform_get_resource(struct platform_device *dev,
54 				       unsigned int type, unsigned int num)
55 {
56 	u32 i;
57 
58 	for (i = 0; i < dev->num_resources; i++) {
59 		struct resource *r = &dev->resource[i];
60 
61 		if (type == resource_type(r) && num-- == 0)
62 			return r;
63 	}
64 	return NULL;
65 }
66 EXPORT_SYMBOL_GPL(platform_get_resource);
67 
68 #ifdef CONFIG_HAS_IOMEM
69 /**
70  * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a
71  *					    platform device and get resource
72  *
73  * @pdev: platform device to use both for memory resource lookup as well as
74  *        resource management
75  * @index: resource index
76  * @res: optional output parameter to store a pointer to the obtained resource.
77  *
78  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
79  * on failure.
80  */
81 void __iomem *
82 devm_platform_get_and_ioremap_resource(struct platform_device *pdev,
83 				unsigned int index, struct resource **res)
84 {
85 	struct resource *r;
86 
87 	r = platform_get_resource(pdev, IORESOURCE_MEM, index);
88 	if (res)
89 		*res = r;
90 	return devm_ioremap_resource(&pdev->dev, r);
91 }
92 EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource);
93 
94 /**
95  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
96  *				    device
97  *
98  * @pdev: platform device to use both for memory resource lookup as well as
99  *        resource management
100  * @index: resource index
101  *
102  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
103  * on failure.
104  */
105 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
106 					     unsigned int index)
107 {
108 	return devm_platform_get_and_ioremap_resource(pdev, index, NULL);
109 }
110 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
111 
112 /**
113  * devm_platform_ioremap_resource_wc - write-combined variant of
114  *                                     devm_platform_ioremap_resource()
115  *
116  * @pdev: platform device to use both for memory resource lookup as well as
117  *        resource management
118  * @index: resource index
119  *
120  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
121  * on failure.
122  */
123 void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev,
124 						unsigned int index)
125 {
126 	struct resource *res;
127 
128 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
129 	return devm_ioremap_resource_wc(&pdev->dev, res);
130 }
131 
132 /**
133  * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
134  *					   a platform device, retrieve the
135  *					   resource by name
136  *
137  * @pdev: platform device to use both for memory resource lookup as well as
138  *	  resource management
139  * @name: name of the resource
140  *
141  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
142  * on failure.
143  */
144 void __iomem *
145 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
146 				      const char *name)
147 {
148 	struct resource *res;
149 
150 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
151 	return devm_ioremap_resource(&pdev->dev, res);
152 }
153 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
154 #endif /* CONFIG_HAS_IOMEM */
155 
156 /**
157  * platform_get_irq_optional - get an optional IRQ for a device
158  * @dev: platform device
159  * @num: IRQ number index
160  *
161  * Gets an IRQ for a platform device. Device drivers should check the return
162  * value for errors so as to not pass a negative integer value to the
163  * request_irq() APIs. This is the same as platform_get_irq(), except that it
164  * does not print an error message if an IRQ can not be obtained.
165  *
166  * For example::
167  *
168  *		int irq = platform_get_irq_optional(pdev, 0);
169  *		if (irq < 0)
170  *			return irq;
171  *
172  * Return: non-zero IRQ number on success, negative error number on failure.
173  */
174 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
175 {
176 	int ret;
177 #ifdef CONFIG_SPARC
178 	/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
179 	if (!dev || num >= dev->archdata.num_irqs)
180 		return -ENXIO;
181 	ret = dev->archdata.irqs[num];
182 	goto out;
183 #else
184 	struct resource *r;
185 
186 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
187 		ret = of_irq_get(dev->dev.of_node, num);
188 		if (ret > 0 || ret == -EPROBE_DEFER)
189 			goto out;
190 	}
191 
192 	r = platform_get_resource(dev, IORESOURCE_IRQ, num);
193 	if (has_acpi_companion(&dev->dev)) {
194 		if (r && r->flags & IORESOURCE_DISABLED) {
195 			ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
196 			if (ret)
197 				goto out;
198 		}
199 	}
200 
201 	/*
202 	 * The resources may pass trigger flags to the irqs that need
203 	 * to be set up. It so happens that the trigger flags for
204 	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
205 	 * settings.
206 	 */
207 	if (r && r->flags & IORESOURCE_BITS) {
208 		struct irq_data *irqd;
209 
210 		irqd = irq_get_irq_data(r->start);
211 		if (!irqd) {
212 			ret = -ENXIO;
213 			goto out;
214 		}
215 		irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
216 	}
217 
218 	if (r) {
219 		ret = r->start;
220 		goto out;
221 	}
222 
223 	/*
224 	 * For the index 0 interrupt, allow falling back to GpioInt
225 	 * resources. While a device could have both Interrupt and GpioInt
226 	 * resources, making this fallback ambiguous, in many common cases
227 	 * the device will only expose one IRQ, and this fallback
228 	 * allows a common code path across either kind of resource.
229 	 */
230 	if (num == 0 && has_acpi_companion(&dev->dev)) {
231 		ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
232 		/* Our callers expect -ENXIO for missing IRQs. */
233 		if (ret >= 0 || ret == -EPROBE_DEFER)
234 			goto out;
235 	}
236 
237 	ret = -ENXIO;
238 #endif
239 out:
240 	WARN(ret == 0, "0 is an invalid IRQ number\n");
241 	return ret;
242 }
243 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
244 
245 /**
246  * platform_get_irq - get an IRQ for a device
247  * @dev: platform device
248  * @num: IRQ number index
249  *
250  * Gets an IRQ for a platform device and prints an error message if finding the
251  * IRQ fails. Device drivers should check the return value for errors so as to
252  * not pass a negative integer value to the request_irq() APIs.
253  *
254  * For example::
255  *
256  *		int irq = platform_get_irq(pdev, 0);
257  *		if (irq < 0)
258  *			return irq;
259  *
260  * Return: non-zero IRQ number on success, negative error number on failure.
261  */
262 int platform_get_irq(struct platform_device *dev, unsigned int num)
263 {
264 	int ret;
265 
266 	ret = platform_get_irq_optional(dev, num);
267 	if (ret < 0 && ret != -EPROBE_DEFER)
268 		dev_err(&dev->dev, "IRQ index %u not found\n", num);
269 
270 	return ret;
271 }
272 EXPORT_SYMBOL_GPL(platform_get_irq);
273 
274 /**
275  * platform_irq_count - Count the number of IRQs a platform device uses
276  * @dev: platform device
277  *
278  * Return: Number of IRQs a platform device uses or EPROBE_DEFER
279  */
280 int platform_irq_count(struct platform_device *dev)
281 {
282 	int ret, nr = 0;
283 
284 	while ((ret = platform_get_irq_optional(dev, nr)) >= 0)
285 		nr++;
286 
287 	if (ret == -EPROBE_DEFER)
288 		return ret;
289 
290 	return nr;
291 }
292 EXPORT_SYMBOL_GPL(platform_irq_count);
293 
294 struct irq_affinity_devres {
295 	unsigned int count;
296 	unsigned int irq[];
297 };
298 
299 static void platform_disable_acpi_irq(struct platform_device *pdev, int index)
300 {
301 	struct resource *r;
302 
303 	r = platform_get_resource(pdev, IORESOURCE_IRQ, index);
304 	if (r)
305 		irqresource_disabled(r, 0);
306 }
307 
308 static void devm_platform_get_irqs_affinity_release(struct device *dev,
309 						    void *res)
310 {
311 	struct irq_affinity_devres *ptr = res;
312 	int i;
313 
314 	for (i = 0; i < ptr->count; i++) {
315 		irq_dispose_mapping(ptr->irq[i]);
316 
317 		if (has_acpi_companion(dev))
318 			platform_disable_acpi_irq(to_platform_device(dev), i);
319 	}
320 }
321 
322 /**
323  * devm_platform_get_irqs_affinity - devm method to get a set of IRQs for a
324  *				device using an interrupt affinity descriptor
325  * @dev: platform device pointer
326  * @affd: affinity descriptor
327  * @minvec: minimum count of interrupt vectors
328  * @maxvec: maximum count of interrupt vectors
329  * @irqs: pointer holder for IRQ numbers
330  *
331  * Gets a set of IRQs for a platform device, and updates IRQ afffinty according
332  * to the passed affinity descriptor
333  *
334  * Return: Number of vectors on success, negative error number on failure.
335  */
336 int devm_platform_get_irqs_affinity(struct platform_device *dev,
337 				    struct irq_affinity *affd,
338 				    unsigned int minvec,
339 				    unsigned int maxvec,
340 				    int **irqs)
341 {
342 	struct irq_affinity_devres *ptr;
343 	struct irq_affinity_desc *desc;
344 	size_t size;
345 	int i, ret, nvec;
346 
347 	if (!affd)
348 		return -EPERM;
349 
350 	if (maxvec < minvec)
351 		return -ERANGE;
352 
353 	nvec = platform_irq_count(dev);
354 
355 	if (nvec < minvec)
356 		return -ENOSPC;
357 
358 	nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
359 	if (nvec < minvec)
360 		return -ENOSPC;
361 
362 	if (nvec > maxvec)
363 		nvec = maxvec;
364 
365 	size = sizeof(*ptr) + sizeof(unsigned int) * nvec;
366 	ptr = devres_alloc(devm_platform_get_irqs_affinity_release, size,
367 			   GFP_KERNEL);
368 	if (!ptr)
369 		return -ENOMEM;
370 
371 	ptr->count = nvec;
372 
373 	for (i = 0; i < nvec; i++) {
374 		int irq = platform_get_irq(dev, i);
375 		if (irq < 0) {
376 			ret = irq;
377 			goto err_free_devres;
378 		}
379 		ptr->irq[i] = irq;
380 	}
381 
382 	desc = irq_create_affinity_masks(nvec, affd);
383 	if (!desc) {
384 		ret = -ENOMEM;
385 		goto err_free_devres;
386 	}
387 
388 	for (i = 0; i < nvec; i++) {
389 		ret = irq_update_affinity_desc(ptr->irq[i], &desc[i]);
390 		if (ret) {
391 			dev_err(&dev->dev, "failed to update irq%d affinity descriptor (%d)\n",
392 				ptr->irq[i], ret);
393 			goto err_free_desc;
394 		}
395 	}
396 
397 	devres_add(&dev->dev, ptr);
398 
399 	kfree(desc);
400 
401 	*irqs = ptr->irq;
402 
403 	return nvec;
404 
405 err_free_desc:
406 	kfree(desc);
407 err_free_devres:
408 	devres_free(ptr);
409 	return ret;
410 }
411 EXPORT_SYMBOL_GPL(devm_platform_get_irqs_affinity);
412 
413 /**
414  * platform_get_resource_byname - get a resource for a device by name
415  * @dev: platform device
416  * @type: resource type
417  * @name: resource name
418  */
419 struct resource *platform_get_resource_byname(struct platform_device *dev,
420 					      unsigned int type,
421 					      const char *name)
422 {
423 	u32 i;
424 
425 	for (i = 0; i < dev->num_resources; i++) {
426 		struct resource *r = &dev->resource[i];
427 
428 		if (unlikely(!r->name))
429 			continue;
430 
431 		if (type == resource_type(r) && !strcmp(r->name, name))
432 			return r;
433 	}
434 	return NULL;
435 }
436 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
437 
438 static int __platform_get_irq_byname(struct platform_device *dev,
439 				     const char *name)
440 {
441 	struct resource *r;
442 	int ret;
443 
444 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
445 		ret = of_irq_get_byname(dev->dev.of_node, name);
446 		if (ret > 0 || ret == -EPROBE_DEFER)
447 			return ret;
448 	}
449 
450 	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
451 	if (r) {
452 		WARN(r->start == 0, "0 is an invalid IRQ number\n");
453 		return r->start;
454 	}
455 
456 	return -ENXIO;
457 }
458 
459 /**
460  * platform_get_irq_byname - get an IRQ for a device by name
461  * @dev: platform device
462  * @name: IRQ name
463  *
464  * Get an IRQ like platform_get_irq(), but then by name rather then by index.
465  *
466  * Return: non-zero IRQ number on success, negative error number on failure.
467  */
468 int platform_get_irq_byname(struct platform_device *dev, const char *name)
469 {
470 	int ret;
471 
472 	ret = __platform_get_irq_byname(dev, name);
473 	if (ret < 0 && ret != -EPROBE_DEFER)
474 		dev_err(&dev->dev, "IRQ %s not found\n", name);
475 
476 	return ret;
477 }
478 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
479 
480 /**
481  * platform_get_irq_byname_optional - get an optional IRQ for a device by name
482  * @dev: platform device
483  * @name: IRQ name
484  *
485  * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
486  * does not print an error message if an IRQ can not be obtained.
487  *
488  * Return: non-zero IRQ number on success, negative error number on failure.
489  */
490 int platform_get_irq_byname_optional(struct platform_device *dev,
491 				     const char *name)
492 {
493 	return __platform_get_irq_byname(dev, name);
494 }
495 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
496 
497 /**
498  * platform_add_devices - add a numbers of platform devices
499  * @devs: array of platform devices to add
500  * @num: number of platform devices in array
501  */
502 int platform_add_devices(struct platform_device **devs, int num)
503 {
504 	int i, ret = 0;
505 
506 	for (i = 0; i < num; i++) {
507 		ret = platform_device_register(devs[i]);
508 		if (ret) {
509 			while (--i >= 0)
510 				platform_device_unregister(devs[i]);
511 			break;
512 		}
513 	}
514 
515 	return ret;
516 }
517 EXPORT_SYMBOL_GPL(platform_add_devices);
518 
519 struct platform_object {
520 	struct platform_device pdev;
521 	char name[];
522 };
523 
524 /*
525  * Set up default DMA mask for platform devices if the they weren't
526  * previously set by the architecture / DT.
527  */
528 static void setup_pdev_dma_masks(struct platform_device *pdev)
529 {
530 	pdev->dev.dma_parms = &pdev->dma_parms;
531 
532 	if (!pdev->dev.coherent_dma_mask)
533 		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
534 	if (!pdev->dev.dma_mask) {
535 		pdev->platform_dma_mask = DMA_BIT_MASK(32);
536 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
537 	}
538 };
539 
540 /**
541  * platform_device_put - destroy a platform device
542  * @pdev: platform device to free
543  *
544  * Free all memory associated with a platform device.  This function must
545  * _only_ be externally called in error cases.  All other usage is a bug.
546  */
547 void platform_device_put(struct platform_device *pdev)
548 {
549 	if (!IS_ERR_OR_NULL(pdev))
550 		put_device(&pdev->dev);
551 }
552 EXPORT_SYMBOL_GPL(platform_device_put);
553 
554 static void platform_device_release(struct device *dev)
555 {
556 	struct platform_object *pa = container_of(dev, struct platform_object,
557 						  pdev.dev);
558 
559 	of_device_node_put(&pa->pdev.dev);
560 	kfree(pa->pdev.dev.platform_data);
561 	kfree(pa->pdev.mfd_cell);
562 	kfree(pa->pdev.resource);
563 	kfree(pa->pdev.driver_override);
564 	kfree(pa);
565 }
566 
567 /**
568  * platform_device_alloc - create a platform device
569  * @name: base name of the device we're adding
570  * @id: instance id
571  *
572  * Create a platform device object which can have other objects attached
573  * to it, and which will have attached objects freed when it is released.
574  */
575 struct platform_device *platform_device_alloc(const char *name, int id)
576 {
577 	struct platform_object *pa;
578 
579 	pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
580 	if (pa) {
581 		strcpy(pa->name, name);
582 		pa->pdev.name = pa->name;
583 		pa->pdev.id = id;
584 		device_initialize(&pa->pdev.dev);
585 		pa->pdev.dev.release = platform_device_release;
586 		setup_pdev_dma_masks(&pa->pdev);
587 	}
588 
589 	return pa ? &pa->pdev : NULL;
590 }
591 EXPORT_SYMBOL_GPL(platform_device_alloc);
592 
593 /**
594  * platform_device_add_resources - add resources to a platform device
595  * @pdev: platform device allocated by platform_device_alloc to add resources to
596  * @res: set of resources that needs to be allocated for the device
597  * @num: number of resources
598  *
599  * Add a copy of the resources to the platform device.  The memory
600  * associated with the resources will be freed when the platform device is
601  * released.
602  */
603 int platform_device_add_resources(struct platform_device *pdev,
604 				  const struct resource *res, unsigned int num)
605 {
606 	struct resource *r = NULL;
607 
608 	if (res) {
609 		r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
610 		if (!r)
611 			return -ENOMEM;
612 	}
613 
614 	kfree(pdev->resource);
615 	pdev->resource = r;
616 	pdev->num_resources = num;
617 	return 0;
618 }
619 EXPORT_SYMBOL_GPL(platform_device_add_resources);
620 
621 /**
622  * platform_device_add_data - add platform-specific data to a platform device
623  * @pdev: platform device allocated by platform_device_alloc to add resources to
624  * @data: platform specific data for this platform device
625  * @size: size of platform specific data
626  *
627  * Add a copy of platform specific data to the platform device's
628  * platform_data pointer.  The memory associated with the platform data
629  * will be freed when the platform device is released.
630  */
631 int platform_device_add_data(struct platform_device *pdev, const void *data,
632 			     size_t size)
633 {
634 	void *d = NULL;
635 
636 	if (data) {
637 		d = kmemdup(data, size, GFP_KERNEL);
638 		if (!d)
639 			return -ENOMEM;
640 	}
641 
642 	kfree(pdev->dev.platform_data);
643 	pdev->dev.platform_data = d;
644 	return 0;
645 }
646 EXPORT_SYMBOL_GPL(platform_device_add_data);
647 
648 /**
649  * platform_device_add_properties - add built-in properties to a platform device
650  * @pdev: platform device to add properties to
651  * @properties: null terminated array of properties to add
652  *
653  * The function will take deep copy of @properties and attach the copy to the
654  * platform device. The memory associated with properties will be freed when the
655  * platform device is released.
656  */
657 int platform_device_add_properties(struct platform_device *pdev,
658 				   const struct property_entry *properties)
659 {
660 	return device_add_properties(&pdev->dev, properties);
661 }
662 EXPORT_SYMBOL_GPL(platform_device_add_properties);
663 
664 /**
665  * platform_device_add - add a platform device to device hierarchy
666  * @pdev: platform device we're adding
667  *
668  * This is part 2 of platform_device_register(), though may be called
669  * separately _iff_ pdev was allocated by platform_device_alloc().
670  */
671 int platform_device_add(struct platform_device *pdev)
672 {
673 	u32 i;
674 	int ret;
675 
676 	if (!pdev)
677 		return -EINVAL;
678 
679 	if (!pdev->dev.parent)
680 		pdev->dev.parent = &platform_bus;
681 
682 	pdev->dev.bus = &platform_bus_type;
683 
684 	switch (pdev->id) {
685 	default:
686 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
687 		break;
688 	case PLATFORM_DEVID_NONE:
689 		dev_set_name(&pdev->dev, "%s", pdev->name);
690 		break;
691 	case PLATFORM_DEVID_AUTO:
692 		/*
693 		 * Automatically allocated device ID. We mark it as such so
694 		 * that we remember it must be freed, and we append a suffix
695 		 * to avoid namespace collision with explicit IDs.
696 		 */
697 		ret = ida_alloc(&platform_devid_ida, GFP_KERNEL);
698 		if (ret < 0)
699 			goto err_out;
700 		pdev->id = ret;
701 		pdev->id_auto = true;
702 		dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
703 		break;
704 	}
705 
706 	for (i = 0; i < pdev->num_resources; i++) {
707 		struct resource *p, *r = &pdev->resource[i];
708 
709 		if (r->name == NULL)
710 			r->name = dev_name(&pdev->dev);
711 
712 		p = r->parent;
713 		if (!p) {
714 			if (resource_type(r) == IORESOURCE_MEM)
715 				p = &iomem_resource;
716 			else if (resource_type(r) == IORESOURCE_IO)
717 				p = &ioport_resource;
718 		}
719 
720 		if (p) {
721 			ret = insert_resource(p, r);
722 			if (ret) {
723 				dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
724 				goto failed;
725 			}
726 		}
727 	}
728 
729 	pr_debug("Registering platform device '%s'. Parent at %s\n",
730 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
731 
732 	ret = device_add(&pdev->dev);
733 	if (ret == 0)
734 		return ret;
735 
736  failed:
737 	if (pdev->id_auto) {
738 		ida_free(&platform_devid_ida, pdev->id);
739 		pdev->id = PLATFORM_DEVID_AUTO;
740 	}
741 
742 	while (i--) {
743 		struct resource *r = &pdev->resource[i];
744 		if (r->parent)
745 			release_resource(r);
746 	}
747 
748  err_out:
749 	return ret;
750 }
751 EXPORT_SYMBOL_GPL(platform_device_add);
752 
753 /**
754  * platform_device_del - remove a platform-level device
755  * @pdev: platform device we're removing
756  *
757  * Note that this function will also release all memory- and port-based
758  * resources owned by the device (@dev->resource).  This function must
759  * _only_ be externally called in error cases.  All other usage is a bug.
760  */
761 void platform_device_del(struct platform_device *pdev)
762 {
763 	u32 i;
764 
765 	if (!IS_ERR_OR_NULL(pdev)) {
766 		device_del(&pdev->dev);
767 
768 		if (pdev->id_auto) {
769 			ida_free(&platform_devid_ida, pdev->id);
770 			pdev->id = PLATFORM_DEVID_AUTO;
771 		}
772 
773 		for (i = 0; i < pdev->num_resources; i++) {
774 			struct resource *r = &pdev->resource[i];
775 			if (r->parent)
776 				release_resource(r);
777 		}
778 	}
779 }
780 EXPORT_SYMBOL_GPL(platform_device_del);
781 
782 /**
783  * platform_device_register - add a platform-level device
784  * @pdev: platform device we're adding
785  */
786 int platform_device_register(struct platform_device *pdev)
787 {
788 	device_initialize(&pdev->dev);
789 	setup_pdev_dma_masks(pdev);
790 	return platform_device_add(pdev);
791 }
792 EXPORT_SYMBOL_GPL(platform_device_register);
793 
794 /**
795  * platform_device_unregister - unregister a platform-level device
796  * @pdev: platform device we're unregistering
797  *
798  * Unregistration is done in 2 steps. First we release all resources
799  * and remove it from the subsystem, then we drop reference count by
800  * calling platform_device_put().
801  */
802 void platform_device_unregister(struct platform_device *pdev)
803 {
804 	platform_device_del(pdev);
805 	platform_device_put(pdev);
806 }
807 EXPORT_SYMBOL_GPL(platform_device_unregister);
808 
809 /**
810  * platform_device_register_full - add a platform-level device with
811  * resources and platform-specific data
812  *
813  * @pdevinfo: data used to create device
814  *
815  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
816  */
817 struct platform_device *platform_device_register_full(
818 		const struct platform_device_info *pdevinfo)
819 {
820 	int ret;
821 	struct platform_device *pdev;
822 
823 	pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
824 	if (!pdev)
825 		return ERR_PTR(-ENOMEM);
826 
827 	pdev->dev.parent = pdevinfo->parent;
828 	pdev->dev.fwnode = pdevinfo->fwnode;
829 	pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
830 	pdev->dev.of_node_reused = pdevinfo->of_node_reused;
831 
832 	if (pdevinfo->dma_mask) {
833 		pdev->platform_dma_mask = pdevinfo->dma_mask;
834 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
835 		pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
836 	}
837 
838 	ret = platform_device_add_resources(pdev,
839 			pdevinfo->res, pdevinfo->num_res);
840 	if (ret)
841 		goto err;
842 
843 	ret = platform_device_add_data(pdev,
844 			pdevinfo->data, pdevinfo->size_data);
845 	if (ret)
846 		goto err;
847 
848 	if (pdevinfo->properties) {
849 		ret = platform_device_add_properties(pdev,
850 						     pdevinfo->properties);
851 		if (ret)
852 			goto err;
853 	}
854 
855 	ret = platform_device_add(pdev);
856 	if (ret) {
857 err:
858 		ACPI_COMPANION_SET(&pdev->dev, NULL);
859 		platform_device_put(pdev);
860 		return ERR_PTR(ret);
861 	}
862 
863 	return pdev;
864 }
865 EXPORT_SYMBOL_GPL(platform_device_register_full);
866 
867 static int platform_drv_probe(struct device *_dev)
868 {
869 	struct platform_driver *drv = to_platform_driver(_dev->driver);
870 	struct platform_device *dev = to_platform_device(_dev);
871 	int ret;
872 
873 	ret = of_clk_set_defaults(_dev->of_node, false);
874 	if (ret < 0)
875 		return ret;
876 
877 	ret = dev_pm_domain_attach(_dev, true);
878 	if (ret)
879 		goto out;
880 
881 	if (drv->probe) {
882 		ret = drv->probe(dev);
883 		if (ret)
884 			dev_pm_domain_detach(_dev, true);
885 	}
886 
887 out:
888 	if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
889 		dev_warn(_dev, "probe deferral not supported\n");
890 		ret = -ENXIO;
891 	}
892 
893 	return ret;
894 }
895 
896 static int platform_drv_probe_fail(struct device *_dev)
897 {
898 	return -ENXIO;
899 }
900 
901 static int platform_drv_remove(struct device *_dev)
902 {
903 	struct platform_driver *drv = to_platform_driver(_dev->driver);
904 	struct platform_device *dev = to_platform_device(_dev);
905 	int ret = 0;
906 
907 	if (drv->remove)
908 		ret = drv->remove(dev);
909 	dev_pm_domain_detach(_dev, true);
910 
911 	return ret;
912 }
913 
914 static void platform_drv_shutdown(struct device *_dev)
915 {
916 	struct platform_driver *drv = to_platform_driver(_dev->driver);
917 	struct platform_device *dev = to_platform_device(_dev);
918 
919 	if (drv->shutdown)
920 		drv->shutdown(dev);
921 }
922 
923 /**
924  * __platform_driver_register - register a driver for platform-level devices
925  * @drv: platform driver structure
926  * @owner: owning module/driver
927  */
928 int __platform_driver_register(struct platform_driver *drv,
929 				struct module *owner)
930 {
931 	drv->driver.owner = owner;
932 	drv->driver.bus = &platform_bus_type;
933 	drv->driver.probe = platform_drv_probe;
934 	drv->driver.remove = platform_drv_remove;
935 	drv->driver.shutdown = platform_drv_shutdown;
936 
937 	return driver_register(&drv->driver);
938 }
939 EXPORT_SYMBOL_GPL(__platform_driver_register);
940 
941 /**
942  * platform_driver_unregister - unregister a driver for platform-level devices
943  * @drv: platform driver structure
944  */
945 void platform_driver_unregister(struct platform_driver *drv)
946 {
947 	driver_unregister(&drv->driver);
948 }
949 EXPORT_SYMBOL_GPL(platform_driver_unregister);
950 
951 /**
952  * __platform_driver_probe - register driver for non-hotpluggable device
953  * @drv: platform driver structure
954  * @probe: the driver probe routine, probably from an __init section
955  * @module: module which will be the owner of the driver
956  *
957  * Use this instead of platform_driver_register() when you know the device
958  * is not hotpluggable and has already been registered, and you want to
959  * remove its run-once probe() infrastructure from memory after the driver
960  * has bound to the device.
961  *
962  * One typical use for this would be with drivers for controllers integrated
963  * into system-on-chip processors, where the controller devices have been
964  * configured as part of board setup.
965  *
966  * Note that this is incompatible with deferred probing.
967  *
968  * Returns zero if the driver registered and bound to a device, else returns
969  * a negative error code and with the driver not registered.
970  */
971 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
972 		int (*probe)(struct platform_device *), struct module *module)
973 {
974 	int retval, code;
975 
976 	if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
977 		pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
978 			 drv->driver.name, __func__);
979 		return -EINVAL;
980 	}
981 
982 	/*
983 	 * We have to run our probes synchronously because we check if
984 	 * we find any devices to bind to and exit with error if there
985 	 * are any.
986 	 */
987 	drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
988 
989 	/*
990 	 * Prevent driver from requesting probe deferral to avoid further
991 	 * futile probe attempts.
992 	 */
993 	drv->prevent_deferred_probe = true;
994 
995 	/* make sure driver won't have bind/unbind attributes */
996 	drv->driver.suppress_bind_attrs = true;
997 
998 	/* temporary section violation during probe() */
999 	drv->probe = probe;
1000 	retval = code = __platform_driver_register(drv, module);
1001 	if (retval)
1002 		return retval;
1003 
1004 	/*
1005 	 * Fixup that section violation, being paranoid about code scanning
1006 	 * the list of drivers in order to probe new devices.  Check to see
1007 	 * if the probe was successful, and make sure any forced probes of
1008 	 * new devices fail.
1009 	 */
1010 	spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
1011 	drv->probe = NULL;
1012 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
1013 		retval = -ENODEV;
1014 	drv->driver.probe = platform_drv_probe_fail;
1015 	spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
1016 
1017 	if (code != retval)
1018 		platform_driver_unregister(drv);
1019 	return retval;
1020 }
1021 EXPORT_SYMBOL_GPL(__platform_driver_probe);
1022 
1023 /**
1024  * __platform_create_bundle - register driver and create corresponding device
1025  * @driver: platform driver structure
1026  * @probe: the driver probe routine, probably from an __init section
1027  * @res: set of resources that needs to be allocated for the device
1028  * @n_res: number of resources
1029  * @data: platform specific data for this platform device
1030  * @size: size of platform specific data
1031  * @module: module which will be the owner of the driver
1032  *
1033  * Use this in legacy-style modules that probe hardware directly and
1034  * register a single platform device and corresponding platform driver.
1035  *
1036  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
1037  */
1038 struct platform_device * __init_or_module __platform_create_bundle(
1039 			struct platform_driver *driver,
1040 			int (*probe)(struct platform_device *),
1041 			struct resource *res, unsigned int n_res,
1042 			const void *data, size_t size, struct module *module)
1043 {
1044 	struct platform_device *pdev;
1045 	int error;
1046 
1047 	pdev = platform_device_alloc(driver->driver.name, -1);
1048 	if (!pdev) {
1049 		error = -ENOMEM;
1050 		goto err_out;
1051 	}
1052 
1053 	error = platform_device_add_resources(pdev, res, n_res);
1054 	if (error)
1055 		goto err_pdev_put;
1056 
1057 	error = platform_device_add_data(pdev, data, size);
1058 	if (error)
1059 		goto err_pdev_put;
1060 
1061 	error = platform_device_add(pdev);
1062 	if (error)
1063 		goto err_pdev_put;
1064 
1065 	error = __platform_driver_probe(driver, probe, module);
1066 	if (error)
1067 		goto err_pdev_del;
1068 
1069 	return pdev;
1070 
1071 err_pdev_del:
1072 	platform_device_del(pdev);
1073 err_pdev_put:
1074 	platform_device_put(pdev);
1075 err_out:
1076 	return ERR_PTR(error);
1077 }
1078 EXPORT_SYMBOL_GPL(__platform_create_bundle);
1079 
1080 /**
1081  * __platform_register_drivers - register an array of platform drivers
1082  * @drivers: an array of drivers to register
1083  * @count: the number of drivers to register
1084  * @owner: module owning the drivers
1085  *
1086  * Registers platform drivers specified by an array. On failure to register a
1087  * driver, all previously registered drivers will be unregistered. Callers of
1088  * this API should use platform_unregister_drivers() to unregister drivers in
1089  * the reverse order.
1090  *
1091  * Returns: 0 on success or a negative error code on failure.
1092  */
1093 int __platform_register_drivers(struct platform_driver * const *drivers,
1094 				unsigned int count, struct module *owner)
1095 {
1096 	unsigned int i;
1097 	int err;
1098 
1099 	for (i = 0; i < count; i++) {
1100 		pr_debug("registering platform driver %ps\n", drivers[i]);
1101 
1102 		err = __platform_driver_register(drivers[i], owner);
1103 		if (err < 0) {
1104 			pr_err("failed to register platform driver %ps: %d\n",
1105 			       drivers[i], err);
1106 			goto error;
1107 		}
1108 	}
1109 
1110 	return 0;
1111 
1112 error:
1113 	while (i--) {
1114 		pr_debug("unregistering platform driver %ps\n", drivers[i]);
1115 		platform_driver_unregister(drivers[i]);
1116 	}
1117 
1118 	return err;
1119 }
1120 EXPORT_SYMBOL_GPL(__platform_register_drivers);
1121 
1122 /**
1123  * platform_unregister_drivers - unregister an array of platform drivers
1124  * @drivers: an array of drivers to unregister
1125  * @count: the number of drivers to unregister
1126  *
1127  * Unregisters platform drivers specified by an array. This is typically used
1128  * to complement an earlier call to platform_register_drivers(). Drivers are
1129  * unregistered in the reverse order in which they were registered.
1130  */
1131 void platform_unregister_drivers(struct platform_driver * const *drivers,
1132 				 unsigned int count)
1133 {
1134 	while (count--) {
1135 		pr_debug("unregistering platform driver %ps\n", drivers[count]);
1136 		platform_driver_unregister(drivers[count]);
1137 	}
1138 }
1139 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
1140 
1141 /* modalias support enables more hands-off userspace setup:
1142  * (a) environment variable lets new-style hotplug events work once system is
1143  *     fully running:  "modprobe $MODALIAS"
1144  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
1145  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
1146  */
1147 static ssize_t modalias_show(struct device *dev,
1148 			     struct device_attribute *attr, char *buf)
1149 {
1150 	struct platform_device *pdev = to_platform_device(dev);
1151 	int len;
1152 
1153 	len = of_device_modalias(dev, buf, PAGE_SIZE);
1154 	if (len != -ENODEV)
1155 		return len;
1156 
1157 	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
1158 	if (len != -ENODEV)
1159 		return len;
1160 
1161 	return sysfs_emit(buf, "platform:%s\n", pdev->name);
1162 }
1163 static DEVICE_ATTR_RO(modalias);
1164 
1165 static ssize_t driver_override_store(struct device *dev,
1166 				     struct device_attribute *attr,
1167 				     const char *buf, size_t count)
1168 {
1169 	struct platform_device *pdev = to_platform_device(dev);
1170 	char *driver_override, *old, *cp;
1171 
1172 	/* We need to keep extra room for a newline */
1173 	if (count >= (PAGE_SIZE - 1))
1174 		return -EINVAL;
1175 
1176 	driver_override = kstrndup(buf, count, GFP_KERNEL);
1177 	if (!driver_override)
1178 		return -ENOMEM;
1179 
1180 	cp = strchr(driver_override, '\n');
1181 	if (cp)
1182 		*cp = '\0';
1183 
1184 	device_lock(dev);
1185 	old = pdev->driver_override;
1186 	if (strlen(driver_override)) {
1187 		pdev->driver_override = driver_override;
1188 	} else {
1189 		kfree(driver_override);
1190 		pdev->driver_override = NULL;
1191 	}
1192 	device_unlock(dev);
1193 
1194 	kfree(old);
1195 
1196 	return count;
1197 }
1198 
1199 static ssize_t driver_override_show(struct device *dev,
1200 				    struct device_attribute *attr, char *buf)
1201 {
1202 	struct platform_device *pdev = to_platform_device(dev);
1203 	ssize_t len;
1204 
1205 	device_lock(dev);
1206 	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
1207 	device_unlock(dev);
1208 
1209 	return len;
1210 }
1211 static DEVICE_ATTR_RW(driver_override);
1212 
1213 static ssize_t numa_node_show(struct device *dev,
1214 			      struct device_attribute *attr, char *buf)
1215 {
1216 	return sysfs_emit(buf, "%d\n", dev_to_node(dev));
1217 }
1218 static DEVICE_ATTR_RO(numa_node);
1219 
1220 static umode_t platform_dev_attrs_visible(struct kobject *kobj, struct attribute *a,
1221 		int n)
1222 {
1223 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
1224 
1225 	if (a == &dev_attr_numa_node.attr &&
1226 			dev_to_node(dev) == NUMA_NO_NODE)
1227 		return 0;
1228 
1229 	return a->mode;
1230 }
1231 
1232 static struct attribute *platform_dev_attrs[] = {
1233 	&dev_attr_modalias.attr,
1234 	&dev_attr_numa_node.attr,
1235 	&dev_attr_driver_override.attr,
1236 	NULL,
1237 };
1238 
1239 static struct attribute_group platform_dev_group = {
1240 	.attrs = platform_dev_attrs,
1241 	.is_visible = platform_dev_attrs_visible,
1242 };
1243 __ATTRIBUTE_GROUPS(platform_dev);
1244 
1245 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1246 {
1247 	struct platform_device	*pdev = to_platform_device(dev);
1248 	int rc;
1249 
1250 	/* Some devices have extra OF data and an OF-style MODALIAS */
1251 	rc = of_device_uevent_modalias(dev, env);
1252 	if (rc != -ENODEV)
1253 		return rc;
1254 
1255 	rc = acpi_device_uevent_modalias(dev, env);
1256 	if (rc != -ENODEV)
1257 		return rc;
1258 
1259 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1260 			pdev->name);
1261 	return 0;
1262 }
1263 
1264 static const struct platform_device_id *platform_match_id(
1265 			const struct platform_device_id *id,
1266 			struct platform_device *pdev)
1267 {
1268 	while (id->name[0]) {
1269 		if (strcmp(pdev->name, id->name) == 0) {
1270 			pdev->id_entry = id;
1271 			return id;
1272 		}
1273 		id++;
1274 	}
1275 	return NULL;
1276 }
1277 
1278 /**
1279  * platform_match - bind platform device to platform driver.
1280  * @dev: device.
1281  * @drv: driver.
1282  *
1283  * Platform device IDs are assumed to be encoded like this:
1284  * "<name><instance>", where <name> is a short description of the type of
1285  * device, like "pci" or "floppy", and <instance> is the enumerated
1286  * instance of the device, like '0' or '42'.  Driver IDs are simply
1287  * "<name>".  So, extract the <name> from the platform_device structure,
1288  * and compare it against the name of the driver. Return whether they match
1289  * or not.
1290  */
1291 static int platform_match(struct device *dev, struct device_driver *drv)
1292 {
1293 	struct platform_device *pdev = to_platform_device(dev);
1294 	struct platform_driver *pdrv = to_platform_driver(drv);
1295 
1296 	/* When driver_override is set, only bind to the matching driver */
1297 	if (pdev->driver_override)
1298 		return !strcmp(pdev->driver_override, drv->name);
1299 
1300 	/* Attempt an OF style match first */
1301 	if (of_driver_match_device(dev, drv))
1302 		return 1;
1303 
1304 	/* Then try ACPI style match */
1305 	if (acpi_driver_match_device(dev, drv))
1306 		return 1;
1307 
1308 	/* Then try to match against the id table */
1309 	if (pdrv->id_table)
1310 		return platform_match_id(pdrv->id_table, pdev) != NULL;
1311 
1312 	/* fall-back to driver name match */
1313 	return (strcmp(pdev->name, drv->name) == 0);
1314 }
1315 
1316 #ifdef CONFIG_PM_SLEEP
1317 
1318 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1319 {
1320 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1321 	struct platform_device *pdev = to_platform_device(dev);
1322 	int ret = 0;
1323 
1324 	if (dev->driver && pdrv->suspend)
1325 		ret = pdrv->suspend(pdev, mesg);
1326 
1327 	return ret;
1328 }
1329 
1330 static int platform_legacy_resume(struct device *dev)
1331 {
1332 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1333 	struct platform_device *pdev = to_platform_device(dev);
1334 	int ret = 0;
1335 
1336 	if (dev->driver && pdrv->resume)
1337 		ret = pdrv->resume(pdev);
1338 
1339 	return ret;
1340 }
1341 
1342 #endif /* CONFIG_PM_SLEEP */
1343 
1344 #ifdef CONFIG_SUSPEND
1345 
1346 int platform_pm_suspend(struct device *dev)
1347 {
1348 	struct device_driver *drv = dev->driver;
1349 	int ret = 0;
1350 
1351 	if (!drv)
1352 		return 0;
1353 
1354 	if (drv->pm) {
1355 		if (drv->pm->suspend)
1356 			ret = drv->pm->suspend(dev);
1357 	} else {
1358 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1359 	}
1360 
1361 	return ret;
1362 }
1363 
1364 int platform_pm_resume(struct device *dev)
1365 {
1366 	struct device_driver *drv = dev->driver;
1367 	int ret = 0;
1368 
1369 	if (!drv)
1370 		return 0;
1371 
1372 	if (drv->pm) {
1373 		if (drv->pm->resume)
1374 			ret = drv->pm->resume(dev);
1375 	} else {
1376 		ret = platform_legacy_resume(dev);
1377 	}
1378 
1379 	return ret;
1380 }
1381 
1382 #endif /* CONFIG_SUSPEND */
1383 
1384 #ifdef CONFIG_HIBERNATE_CALLBACKS
1385 
1386 int platform_pm_freeze(struct device *dev)
1387 {
1388 	struct device_driver *drv = dev->driver;
1389 	int ret = 0;
1390 
1391 	if (!drv)
1392 		return 0;
1393 
1394 	if (drv->pm) {
1395 		if (drv->pm->freeze)
1396 			ret = drv->pm->freeze(dev);
1397 	} else {
1398 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1399 	}
1400 
1401 	return ret;
1402 }
1403 
1404 int platform_pm_thaw(struct device *dev)
1405 {
1406 	struct device_driver *drv = dev->driver;
1407 	int ret = 0;
1408 
1409 	if (!drv)
1410 		return 0;
1411 
1412 	if (drv->pm) {
1413 		if (drv->pm->thaw)
1414 			ret = drv->pm->thaw(dev);
1415 	} else {
1416 		ret = platform_legacy_resume(dev);
1417 	}
1418 
1419 	return ret;
1420 }
1421 
1422 int platform_pm_poweroff(struct device *dev)
1423 {
1424 	struct device_driver *drv = dev->driver;
1425 	int ret = 0;
1426 
1427 	if (!drv)
1428 		return 0;
1429 
1430 	if (drv->pm) {
1431 		if (drv->pm->poweroff)
1432 			ret = drv->pm->poweroff(dev);
1433 	} else {
1434 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1435 	}
1436 
1437 	return ret;
1438 }
1439 
1440 int platform_pm_restore(struct device *dev)
1441 {
1442 	struct device_driver *drv = dev->driver;
1443 	int ret = 0;
1444 
1445 	if (!drv)
1446 		return 0;
1447 
1448 	if (drv->pm) {
1449 		if (drv->pm->restore)
1450 			ret = drv->pm->restore(dev);
1451 	} else {
1452 		ret = platform_legacy_resume(dev);
1453 	}
1454 
1455 	return ret;
1456 }
1457 
1458 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1459 
1460 int platform_dma_configure(struct device *dev)
1461 {
1462 	enum dev_dma_attr attr;
1463 	int ret = 0;
1464 
1465 	if (dev->of_node) {
1466 		ret = of_dma_configure(dev, dev->of_node, true);
1467 	} else if (has_acpi_companion(dev)) {
1468 		attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1469 		ret = acpi_dma_configure(dev, attr);
1470 	}
1471 
1472 	return ret;
1473 }
1474 
1475 static const struct dev_pm_ops platform_dev_pm_ops = {
1476 	.runtime_suspend = pm_generic_runtime_suspend,
1477 	.runtime_resume = pm_generic_runtime_resume,
1478 	USE_PLATFORM_PM_SLEEP_OPS
1479 };
1480 
1481 struct bus_type platform_bus_type = {
1482 	.name		= "platform",
1483 	.dev_groups	= platform_dev_groups,
1484 	.match		= platform_match,
1485 	.uevent		= platform_uevent,
1486 	.dma_configure	= platform_dma_configure,
1487 	.pm		= &platform_dev_pm_ops,
1488 };
1489 EXPORT_SYMBOL_GPL(platform_bus_type);
1490 
1491 static inline int __platform_match(struct device *dev, const void *drv)
1492 {
1493 	return platform_match(dev, (struct device_driver *)drv);
1494 }
1495 
1496 /**
1497  * platform_find_device_by_driver - Find a platform device with a given
1498  * driver.
1499  * @start: The device to start the search from.
1500  * @drv: The device driver to look for.
1501  */
1502 struct device *platform_find_device_by_driver(struct device *start,
1503 					      const struct device_driver *drv)
1504 {
1505 	return bus_find_device(&platform_bus_type, start, drv,
1506 			       __platform_match);
1507 }
1508 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1509 
1510 void __weak __init early_platform_cleanup(void) { }
1511 
1512 int __init platform_bus_init(void)
1513 {
1514 	int error;
1515 
1516 	early_platform_cleanup();
1517 
1518 	error = device_register(&platform_bus);
1519 	if (error) {
1520 		put_device(&platform_bus);
1521 		return error;
1522 	}
1523 	error =  bus_register(&platform_bus_type);
1524 	if (error)
1525 		device_unregister(&platform_bus);
1526 	of_platform_register_reconfig_notifier();
1527 	return error;
1528 }
1529