xref: /openbmc/linux/drivers/base/platform.c (revision ed7027fd)
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 struct resource *platform_get_mem_or_io(struct platform_device *dev,
69 					unsigned int num)
70 {
71 	u32 i;
72 
73 	for (i = 0; i < dev->num_resources; i++) {
74 		struct resource *r = &dev->resource[i];
75 
76 		if ((resource_type(r) & (IORESOURCE_MEM|IORESOURCE_IO)) && num-- == 0)
77 			return r;
78 	}
79 	return NULL;
80 }
81 EXPORT_SYMBOL_GPL(platform_get_mem_or_io);
82 
83 #ifdef CONFIG_HAS_IOMEM
84 /**
85  * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a
86  *					    platform device and get resource
87  *
88  * @pdev: platform device to use both for memory resource lookup as well as
89  *        resource management
90  * @index: resource index
91  * @res: optional output parameter to store a pointer to the obtained resource.
92  *
93  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
94  * on failure.
95  */
96 void __iomem *
97 devm_platform_get_and_ioremap_resource(struct platform_device *pdev,
98 				unsigned int index, struct resource **res)
99 {
100 	struct resource *r;
101 
102 	r = platform_get_resource(pdev, IORESOURCE_MEM, index);
103 	if (res)
104 		*res = r;
105 	return devm_ioremap_resource(&pdev->dev, r);
106 }
107 EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource);
108 
109 /**
110  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
111  *				    device
112  *
113  * @pdev: platform device to use both for memory resource lookup as well as
114  *        resource management
115  * @index: resource index
116  *
117  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
118  * on failure.
119  */
120 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
121 					     unsigned int index)
122 {
123 	return devm_platform_get_and_ioremap_resource(pdev, index, NULL);
124 }
125 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
126 
127 /**
128  * devm_platform_ioremap_resource_wc - write-combined variant of
129  *                                     devm_platform_ioremap_resource()
130  *
131  * @pdev: platform device to use both for memory resource lookup as well as
132  *        resource management
133  * @index: resource index
134  *
135  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
136  * on failure.
137  */
138 void __iomem *devm_platform_ioremap_resource_wc(struct platform_device *pdev,
139 						unsigned int index)
140 {
141 	struct resource *res;
142 
143 	res = platform_get_resource(pdev, IORESOURCE_MEM, index);
144 	return devm_ioremap_resource_wc(&pdev->dev, res);
145 }
146 
147 /**
148  * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
149  *					   a platform device, retrieve the
150  *					   resource by name
151  *
152  * @pdev: platform device to use both for memory resource lookup as well as
153  *	  resource management
154  * @name: name of the resource
155  *
156  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
157  * on failure.
158  */
159 void __iomem *
160 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
161 				      const char *name)
162 {
163 	struct resource *res;
164 
165 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
166 	return devm_ioremap_resource(&pdev->dev, res);
167 }
168 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
169 #endif /* CONFIG_HAS_IOMEM */
170 
171 static int platform_do_get_irq(struct platform_device *dev, unsigned int num)
172 {
173 	int ret;
174 #ifdef CONFIG_SPARC
175 	/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
176 	if (!dev || num >= dev->archdata.num_irqs)
177 		goto out_not_found;
178 	ret = dev->archdata.irqs[num];
179 	goto out;
180 #else
181 	struct resource *r;
182 
183 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
184 		ret = of_irq_get(dev->dev.of_node, num);
185 		if (ret > 0 || ret == -EPROBE_DEFER)
186 			goto out;
187 	}
188 
189 	r = platform_get_resource(dev, IORESOURCE_IRQ, num);
190 	if (has_acpi_companion(&dev->dev)) {
191 		if (r && r->flags & IORESOURCE_DISABLED) {
192 			ret = acpi_irq_get(ACPI_HANDLE(&dev->dev), num, r);
193 			if (ret)
194 				goto out;
195 		}
196 	}
197 
198 	/*
199 	 * The resources may pass trigger flags to the irqs that need
200 	 * to be set up. It so happens that the trigger flags for
201 	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
202 	 * settings.
203 	 */
204 	if (r && r->flags & IORESOURCE_BITS) {
205 		struct irq_data *irqd;
206 
207 		irqd = irq_get_irq_data(r->start);
208 		if (!irqd)
209 			goto out_not_found;
210 		irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
211 	}
212 
213 	if (r) {
214 		ret = r->start;
215 		goto out;
216 	}
217 
218 	/*
219 	 * For the index 0 interrupt, allow falling back to GpioInt
220 	 * resources. While a device could have both Interrupt and GpioInt
221 	 * resources, making this fallback ambiguous, in many common cases
222 	 * the device will only expose one IRQ, and this fallback
223 	 * allows a common code path across either kind of resource.
224 	 */
225 	if (num == 0 && has_acpi_companion(&dev->dev)) {
226 		ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num);
227 		/* Our callers expect -ENXIO for missing IRQs. */
228 		if (ret >= 0 || ret == -EPROBE_DEFER)
229 			goto out;
230 	}
231 
232 #endif
233 out_not_found:
234 	ret = -ENXIO;
235 out:
236 	WARN(ret == 0, "0 is an invalid IRQ number\n");
237 	return ret;
238 }
239 
240 /**
241  * platform_get_irq_optional - get an optional IRQ for a device
242  * @dev: platform device
243  * @num: IRQ number index
244  *
245  * Gets an IRQ for a platform device. Device drivers should check the return
246  * value for errors so as to not pass a negative integer value to the
247  * request_irq() APIs. This is the same as platform_get_irq(), except that it
248  * does not print an error message if an IRQ can not be obtained and returns
249  * 0 when IRQ resource has not been found.
250  *
251  * For example::
252  *
253  *		int irq = platform_get_irq_optional(pdev, 0);
254  *		if (irq < 0)
255  *			return irq;
256  *		if (irq > 0)
257  *			...we have IRQ line defined...
258  *
259  * Return: non-zero IRQ number on success, negative error number on failure.
260  */
261 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
262 {
263 	int ret;
264 
265 	ret = platform_do_get_irq(dev, num);
266 	if (ret == -ENXIO)
267 		return 0;
268 	return ret;
269 }
270 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
271 
272 /**
273  * platform_get_irq - get an IRQ for a device
274  * @dev: platform device
275  * @num: IRQ number index
276  *
277  * Gets an IRQ for a platform device and prints an error message if finding the
278  * IRQ fails. Device drivers should check the return value for errors so as to
279  * not pass a negative integer value to the request_irq() APIs.
280  *
281  * For example::
282  *
283  *		int irq = platform_get_irq(pdev, 0);
284  *		if (irq < 0)
285  *			return irq;
286  *
287  * Return: non-zero IRQ number on success, negative error number on failure.
288  */
289 int platform_get_irq(struct platform_device *dev, unsigned int num)
290 {
291 	int ret;
292 
293 	ret = platform_do_get_irq(dev, num);
294 	if (ret < 0 && ret != -EPROBE_DEFER)
295 		dev_err(&dev->dev, "IRQ index %u not found\n", num);
296 
297 	return ret;
298 }
299 EXPORT_SYMBOL_GPL(platform_get_irq);
300 
301 /**
302  * platform_irq_count - Count the number of IRQs a platform device uses
303  * @dev: platform device
304  *
305  * Return: Number of IRQs a platform device uses or EPROBE_DEFER
306  */
307 int platform_irq_count(struct platform_device *dev)
308 {
309 	int ret, nr = 0;
310 
311 	while ((ret = platform_do_get_irq(dev, nr)) >= 0)
312 		nr++;
313 
314 	if (ret == -EPROBE_DEFER)
315 		return ret;
316 
317 	return nr;
318 }
319 EXPORT_SYMBOL_GPL(platform_irq_count);
320 
321 struct irq_affinity_devres {
322 	unsigned int count;
323 	unsigned int irq[];
324 };
325 
326 static void platform_disable_acpi_irq(struct platform_device *pdev, int index)
327 {
328 	struct resource *r;
329 
330 	r = platform_get_resource(pdev, IORESOURCE_IRQ, index);
331 	if (r)
332 		irqresource_disabled(r, 0);
333 }
334 
335 static void devm_platform_get_irqs_affinity_release(struct device *dev,
336 						    void *res)
337 {
338 	struct irq_affinity_devres *ptr = res;
339 	int i;
340 
341 	for (i = 0; i < ptr->count; i++) {
342 		irq_dispose_mapping(ptr->irq[i]);
343 
344 		if (has_acpi_companion(dev))
345 			platform_disable_acpi_irq(to_platform_device(dev), i);
346 	}
347 }
348 
349 /**
350  * devm_platform_get_irqs_affinity - devm method to get a set of IRQs for a
351  *				device using an interrupt affinity descriptor
352  * @dev: platform device pointer
353  * @affd: affinity descriptor
354  * @minvec: minimum count of interrupt vectors
355  * @maxvec: maximum count of interrupt vectors
356  * @irqs: pointer holder for IRQ numbers
357  *
358  * Gets a set of IRQs for a platform device, and updates IRQ afffinty according
359  * to the passed affinity descriptor
360  *
361  * Return: Number of vectors on success, negative error number on failure.
362  */
363 int devm_platform_get_irqs_affinity(struct platform_device *dev,
364 				    struct irq_affinity *affd,
365 				    unsigned int minvec,
366 				    unsigned int maxvec,
367 				    int **irqs)
368 {
369 	struct irq_affinity_devres *ptr;
370 	struct irq_affinity_desc *desc;
371 	size_t size;
372 	int i, ret, nvec;
373 
374 	if (!affd)
375 		return -EPERM;
376 
377 	if (maxvec < minvec)
378 		return -ERANGE;
379 
380 	nvec = platform_irq_count(dev);
381 	if (nvec < 0)
382 		return nvec;
383 
384 	if (nvec < minvec)
385 		return -ENOSPC;
386 
387 	nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
388 	if (nvec < minvec)
389 		return -ENOSPC;
390 
391 	if (nvec > maxvec)
392 		nvec = maxvec;
393 
394 	size = sizeof(*ptr) + sizeof(unsigned int) * nvec;
395 	ptr = devres_alloc(devm_platform_get_irqs_affinity_release, size,
396 			   GFP_KERNEL);
397 	if (!ptr)
398 		return -ENOMEM;
399 
400 	ptr->count = nvec;
401 
402 	for (i = 0; i < nvec; i++) {
403 		int irq = platform_get_irq(dev, i);
404 		if (irq < 0) {
405 			ret = irq;
406 			goto err_free_devres;
407 		}
408 		ptr->irq[i] = irq;
409 	}
410 
411 	desc = irq_create_affinity_masks(nvec, affd);
412 	if (!desc) {
413 		ret = -ENOMEM;
414 		goto err_free_devres;
415 	}
416 
417 	for (i = 0; i < nvec; i++) {
418 		ret = irq_update_affinity_desc(ptr->irq[i], &desc[i]);
419 		if (ret) {
420 			dev_err(&dev->dev, "failed to update irq%d affinity descriptor (%d)\n",
421 				ptr->irq[i], ret);
422 			goto err_free_desc;
423 		}
424 	}
425 
426 	devres_add(&dev->dev, ptr);
427 
428 	kfree(desc);
429 
430 	*irqs = ptr->irq;
431 
432 	return nvec;
433 
434 err_free_desc:
435 	kfree(desc);
436 err_free_devres:
437 	devres_free(ptr);
438 	return ret;
439 }
440 EXPORT_SYMBOL_GPL(devm_platform_get_irqs_affinity);
441 
442 /**
443  * platform_get_resource_byname - get a resource for a device by name
444  * @dev: platform device
445  * @type: resource type
446  * @name: resource name
447  */
448 struct resource *platform_get_resource_byname(struct platform_device *dev,
449 					      unsigned int type,
450 					      const char *name)
451 {
452 	u32 i;
453 
454 	for (i = 0; i < dev->num_resources; i++) {
455 		struct resource *r = &dev->resource[i];
456 
457 		if (unlikely(!r->name))
458 			continue;
459 
460 		if (type == resource_type(r) && !strcmp(r->name, name))
461 			return r;
462 	}
463 	return NULL;
464 }
465 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
466 
467 static int __platform_get_irq_byname(struct platform_device *dev,
468 				     const char *name)
469 {
470 	struct resource *r;
471 	int ret;
472 
473 	if (IS_ENABLED(CONFIG_OF_IRQ) && dev->dev.of_node) {
474 		ret = of_irq_get_byname(dev->dev.of_node, name);
475 		if (ret > 0 || ret == -EPROBE_DEFER)
476 			return ret;
477 	}
478 
479 	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
480 	if (r) {
481 		WARN(r->start == 0, "0 is an invalid IRQ number\n");
482 		return r->start;
483 	}
484 
485 	return -ENXIO;
486 }
487 
488 /**
489  * platform_get_irq_byname - get an IRQ for a device by name
490  * @dev: platform device
491  * @name: IRQ name
492  *
493  * Get an IRQ like platform_get_irq(), but then by name rather then by index.
494  *
495  * Return: non-zero IRQ number on success, negative error number on failure.
496  */
497 int platform_get_irq_byname(struct platform_device *dev, const char *name)
498 {
499 	int ret;
500 
501 	ret = __platform_get_irq_byname(dev, name);
502 	if (ret < 0 && ret != -EPROBE_DEFER)
503 		dev_err(&dev->dev, "IRQ %s not found\n", name);
504 
505 	return ret;
506 }
507 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
508 
509 /**
510  * platform_get_irq_byname_optional - get an optional IRQ for a device by name
511  * @dev: platform device
512  * @name: IRQ name
513  *
514  * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
515  * does not print an error message if an IRQ can not be obtained.
516  *
517  * Return: non-zero IRQ number on success, negative error number on failure.
518  */
519 int platform_get_irq_byname_optional(struct platform_device *dev,
520 				     const char *name)
521 {
522 	return __platform_get_irq_byname(dev, name);
523 }
524 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
525 
526 /**
527  * platform_add_devices - add a numbers of platform devices
528  * @devs: array of platform devices to add
529  * @num: number of platform devices in array
530  */
531 int platform_add_devices(struct platform_device **devs, int num)
532 {
533 	int i, ret = 0;
534 
535 	for (i = 0; i < num; i++) {
536 		ret = platform_device_register(devs[i]);
537 		if (ret) {
538 			while (--i >= 0)
539 				platform_device_unregister(devs[i]);
540 			break;
541 		}
542 	}
543 
544 	return ret;
545 }
546 EXPORT_SYMBOL_GPL(platform_add_devices);
547 
548 struct platform_object {
549 	struct platform_device pdev;
550 	char name[];
551 };
552 
553 /*
554  * Set up default DMA mask for platform devices if the they weren't
555  * previously set by the architecture / DT.
556  */
557 static void setup_pdev_dma_masks(struct platform_device *pdev)
558 {
559 	pdev->dev.dma_parms = &pdev->dma_parms;
560 
561 	if (!pdev->dev.coherent_dma_mask)
562 		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
563 	if (!pdev->dev.dma_mask) {
564 		pdev->platform_dma_mask = DMA_BIT_MASK(32);
565 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
566 	}
567 };
568 
569 /**
570  * platform_device_put - destroy a platform device
571  * @pdev: platform device to free
572  *
573  * Free all memory associated with a platform device.  This function must
574  * _only_ be externally called in error cases.  All other usage is a bug.
575  */
576 void platform_device_put(struct platform_device *pdev)
577 {
578 	if (!IS_ERR_OR_NULL(pdev))
579 		put_device(&pdev->dev);
580 }
581 EXPORT_SYMBOL_GPL(platform_device_put);
582 
583 static void platform_device_release(struct device *dev)
584 {
585 	struct platform_object *pa = container_of(dev, struct platform_object,
586 						  pdev.dev);
587 
588 	of_node_put(pa->pdev.dev.of_node);
589 	kfree(pa->pdev.dev.platform_data);
590 	kfree(pa->pdev.mfd_cell);
591 	kfree(pa->pdev.resource);
592 	kfree(pa->pdev.driver_override);
593 	kfree(pa);
594 }
595 
596 /**
597  * platform_device_alloc - create a platform device
598  * @name: base name of the device we're adding
599  * @id: instance id
600  *
601  * Create a platform device object which can have other objects attached
602  * to it, and which will have attached objects freed when it is released.
603  */
604 struct platform_device *platform_device_alloc(const char *name, int id)
605 {
606 	struct platform_object *pa;
607 
608 	pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
609 	if (pa) {
610 		strcpy(pa->name, name);
611 		pa->pdev.name = pa->name;
612 		pa->pdev.id = id;
613 		device_initialize(&pa->pdev.dev);
614 		pa->pdev.dev.release = platform_device_release;
615 		setup_pdev_dma_masks(&pa->pdev);
616 	}
617 
618 	return pa ? &pa->pdev : NULL;
619 }
620 EXPORT_SYMBOL_GPL(platform_device_alloc);
621 
622 /**
623  * platform_device_add_resources - add resources to a platform device
624  * @pdev: platform device allocated by platform_device_alloc to add resources to
625  * @res: set of resources that needs to be allocated for the device
626  * @num: number of resources
627  *
628  * Add a copy of the resources to the platform device.  The memory
629  * associated with the resources will be freed when the platform device is
630  * released.
631  */
632 int platform_device_add_resources(struct platform_device *pdev,
633 				  const struct resource *res, unsigned int num)
634 {
635 	struct resource *r = NULL;
636 
637 	if (res) {
638 		r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
639 		if (!r)
640 			return -ENOMEM;
641 	}
642 
643 	kfree(pdev->resource);
644 	pdev->resource = r;
645 	pdev->num_resources = num;
646 	return 0;
647 }
648 EXPORT_SYMBOL_GPL(platform_device_add_resources);
649 
650 /**
651  * platform_device_add_data - add platform-specific data to a platform device
652  * @pdev: platform device allocated by platform_device_alloc to add resources to
653  * @data: platform specific data for this platform device
654  * @size: size of platform specific data
655  *
656  * Add a copy of platform specific data to the platform device's
657  * platform_data pointer.  The memory associated with the platform data
658  * will be freed when the platform device is released.
659  */
660 int platform_device_add_data(struct platform_device *pdev, const void *data,
661 			     size_t size)
662 {
663 	void *d = NULL;
664 
665 	if (data) {
666 		d = kmemdup(data, size, GFP_KERNEL);
667 		if (!d)
668 			return -ENOMEM;
669 	}
670 
671 	kfree(pdev->dev.platform_data);
672 	pdev->dev.platform_data = d;
673 	return 0;
674 }
675 EXPORT_SYMBOL_GPL(platform_device_add_data);
676 
677 /**
678  * platform_device_add_properties - add built-in properties to a platform device
679  * @pdev: platform device to add properties to
680  * @properties: null terminated array of properties to add
681  *
682  * The function will take deep copy of @properties and attach the copy to the
683  * platform device. The memory associated with properties will be freed when the
684  * platform device is released.
685  */
686 int platform_device_add_properties(struct platform_device *pdev,
687 				   const struct property_entry *properties)
688 {
689 	return device_add_properties(&pdev->dev, properties);
690 }
691 EXPORT_SYMBOL_GPL(platform_device_add_properties);
692 
693 /**
694  * platform_device_add - add a platform device to device hierarchy
695  * @pdev: platform device we're adding
696  *
697  * This is part 2 of platform_device_register(), though may be called
698  * separately _iff_ pdev was allocated by platform_device_alloc().
699  */
700 int platform_device_add(struct platform_device *pdev)
701 {
702 	u32 i;
703 	int ret;
704 
705 	if (!pdev)
706 		return -EINVAL;
707 
708 	if (!pdev->dev.parent)
709 		pdev->dev.parent = &platform_bus;
710 
711 	pdev->dev.bus = &platform_bus_type;
712 
713 	switch (pdev->id) {
714 	default:
715 		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
716 		break;
717 	case PLATFORM_DEVID_NONE:
718 		dev_set_name(&pdev->dev, "%s", pdev->name);
719 		break;
720 	case PLATFORM_DEVID_AUTO:
721 		/*
722 		 * Automatically allocated device ID. We mark it as such so
723 		 * that we remember it must be freed, and we append a suffix
724 		 * to avoid namespace collision with explicit IDs.
725 		 */
726 		ret = ida_alloc(&platform_devid_ida, GFP_KERNEL);
727 		if (ret < 0)
728 			goto err_out;
729 		pdev->id = ret;
730 		pdev->id_auto = true;
731 		dev_set_name(&pdev->dev, "%s.%d.auto", pdev->name, pdev->id);
732 		break;
733 	}
734 
735 	for (i = 0; i < pdev->num_resources; i++) {
736 		struct resource *p, *r = &pdev->resource[i];
737 
738 		if (r->name == NULL)
739 			r->name = dev_name(&pdev->dev);
740 
741 		p = r->parent;
742 		if (!p) {
743 			if (resource_type(r) == IORESOURCE_MEM)
744 				p = &iomem_resource;
745 			else if (resource_type(r) == IORESOURCE_IO)
746 				p = &ioport_resource;
747 		}
748 
749 		if (p) {
750 			ret = insert_resource(p, r);
751 			if (ret) {
752 				dev_err(&pdev->dev, "failed to claim resource %d: %pR\n", i, r);
753 				goto failed;
754 			}
755 		}
756 	}
757 
758 	pr_debug("Registering platform device '%s'. Parent at %s\n",
759 		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));
760 
761 	ret = device_add(&pdev->dev);
762 	if (ret == 0)
763 		return ret;
764 
765  failed:
766 	if (pdev->id_auto) {
767 		ida_free(&platform_devid_ida, pdev->id);
768 		pdev->id = PLATFORM_DEVID_AUTO;
769 	}
770 
771 	while (i--) {
772 		struct resource *r = &pdev->resource[i];
773 		if (r->parent)
774 			release_resource(r);
775 	}
776 
777  err_out:
778 	return ret;
779 }
780 EXPORT_SYMBOL_GPL(platform_device_add);
781 
782 /**
783  * platform_device_del - remove a platform-level device
784  * @pdev: platform device we're removing
785  *
786  * Note that this function will also release all memory- and port-based
787  * resources owned by the device (@dev->resource).  This function must
788  * _only_ be externally called in error cases.  All other usage is a bug.
789  */
790 void platform_device_del(struct platform_device *pdev)
791 {
792 	u32 i;
793 
794 	if (!IS_ERR_OR_NULL(pdev)) {
795 		device_del(&pdev->dev);
796 
797 		if (pdev->id_auto) {
798 			ida_free(&platform_devid_ida, pdev->id);
799 			pdev->id = PLATFORM_DEVID_AUTO;
800 		}
801 
802 		for (i = 0; i < pdev->num_resources; i++) {
803 			struct resource *r = &pdev->resource[i];
804 			if (r->parent)
805 				release_resource(r);
806 		}
807 	}
808 }
809 EXPORT_SYMBOL_GPL(platform_device_del);
810 
811 /**
812  * platform_device_register - add a platform-level device
813  * @pdev: platform device we're adding
814  */
815 int platform_device_register(struct platform_device *pdev)
816 {
817 	device_initialize(&pdev->dev);
818 	setup_pdev_dma_masks(pdev);
819 	return platform_device_add(pdev);
820 }
821 EXPORT_SYMBOL_GPL(platform_device_register);
822 
823 /**
824  * platform_device_unregister - unregister a platform-level device
825  * @pdev: platform device we're unregistering
826  *
827  * Unregistration is done in 2 steps. First we release all resources
828  * and remove it from the subsystem, then we drop reference count by
829  * calling platform_device_put().
830  */
831 void platform_device_unregister(struct platform_device *pdev)
832 {
833 	platform_device_del(pdev);
834 	platform_device_put(pdev);
835 }
836 EXPORT_SYMBOL_GPL(platform_device_unregister);
837 
838 /**
839  * platform_device_register_full - add a platform-level device with
840  * resources and platform-specific data
841  *
842  * @pdevinfo: data used to create device
843  *
844  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
845  */
846 struct platform_device *platform_device_register_full(
847 		const struct platform_device_info *pdevinfo)
848 {
849 	int ret;
850 	struct platform_device *pdev;
851 
852 	pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
853 	if (!pdev)
854 		return ERR_PTR(-ENOMEM);
855 
856 	pdev->dev.parent = pdevinfo->parent;
857 	pdev->dev.fwnode = pdevinfo->fwnode;
858 	pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
859 	pdev->dev.of_node_reused = pdevinfo->of_node_reused;
860 
861 	if (pdevinfo->dma_mask) {
862 		pdev->platform_dma_mask = pdevinfo->dma_mask;
863 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
864 		pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
865 	}
866 
867 	ret = platform_device_add_resources(pdev,
868 			pdevinfo->res, pdevinfo->num_res);
869 	if (ret)
870 		goto err;
871 
872 	ret = platform_device_add_data(pdev,
873 			pdevinfo->data, pdevinfo->size_data);
874 	if (ret)
875 		goto err;
876 
877 	if (pdevinfo->properties) {
878 		ret = platform_device_add_properties(pdev,
879 						     pdevinfo->properties);
880 		if (ret)
881 			goto err;
882 	}
883 
884 	ret = platform_device_add(pdev);
885 	if (ret) {
886 err:
887 		ACPI_COMPANION_SET(&pdev->dev, NULL);
888 		platform_device_put(pdev);
889 		return ERR_PTR(ret);
890 	}
891 
892 	return pdev;
893 }
894 EXPORT_SYMBOL_GPL(platform_device_register_full);
895 
896 /**
897  * __platform_driver_register - register a driver for platform-level devices
898  * @drv: platform driver structure
899  * @owner: owning module/driver
900  */
901 int __platform_driver_register(struct platform_driver *drv,
902 				struct module *owner)
903 {
904 	drv->driver.owner = owner;
905 	drv->driver.bus = &platform_bus_type;
906 
907 	return driver_register(&drv->driver);
908 }
909 EXPORT_SYMBOL_GPL(__platform_driver_register);
910 
911 /**
912  * platform_driver_unregister - unregister a driver for platform-level devices
913  * @drv: platform driver structure
914  */
915 void platform_driver_unregister(struct platform_driver *drv)
916 {
917 	driver_unregister(&drv->driver);
918 }
919 EXPORT_SYMBOL_GPL(platform_driver_unregister);
920 
921 static int platform_probe_fail(struct platform_device *pdev)
922 {
923 	return -ENXIO;
924 }
925 
926 /**
927  * __platform_driver_probe - register driver for non-hotpluggable device
928  * @drv: platform driver structure
929  * @probe: the driver probe routine, probably from an __init section
930  * @module: module which will be the owner of the driver
931  *
932  * Use this instead of platform_driver_register() when you know the device
933  * is not hotpluggable and has already been registered, and you want to
934  * remove its run-once probe() infrastructure from memory after the driver
935  * has bound to the device.
936  *
937  * One typical use for this would be with drivers for controllers integrated
938  * into system-on-chip processors, where the controller devices have been
939  * configured as part of board setup.
940  *
941  * Note that this is incompatible with deferred probing.
942  *
943  * Returns zero if the driver registered and bound to a device, else returns
944  * a negative error code and with the driver not registered.
945  */
946 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
947 		int (*probe)(struct platform_device *), struct module *module)
948 {
949 	int retval, code;
950 
951 	if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
952 		pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
953 			 drv->driver.name, __func__);
954 		return -EINVAL;
955 	}
956 
957 	/*
958 	 * We have to run our probes synchronously because we check if
959 	 * we find any devices to bind to and exit with error if there
960 	 * are any.
961 	 */
962 	drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
963 
964 	/*
965 	 * Prevent driver from requesting probe deferral to avoid further
966 	 * futile probe attempts.
967 	 */
968 	drv->prevent_deferred_probe = true;
969 
970 	/* make sure driver won't have bind/unbind attributes */
971 	drv->driver.suppress_bind_attrs = true;
972 
973 	/* temporary section violation during probe() */
974 	drv->probe = probe;
975 	retval = code = __platform_driver_register(drv, module);
976 	if (retval)
977 		return retval;
978 
979 	/*
980 	 * Fixup that section violation, being paranoid about code scanning
981 	 * the list of drivers in order to probe new devices.  Check to see
982 	 * if the probe was successful, and make sure any forced probes of
983 	 * new devices fail.
984 	 */
985 	spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
986 	drv->probe = platform_probe_fail;
987 	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
988 		retval = -ENODEV;
989 	spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);
990 
991 	if (code != retval)
992 		platform_driver_unregister(drv);
993 	return retval;
994 }
995 EXPORT_SYMBOL_GPL(__platform_driver_probe);
996 
997 /**
998  * __platform_create_bundle - register driver and create corresponding device
999  * @driver: platform driver structure
1000  * @probe: the driver probe routine, probably from an __init section
1001  * @res: set of resources that needs to be allocated for the device
1002  * @n_res: number of resources
1003  * @data: platform specific data for this platform device
1004  * @size: size of platform specific data
1005  * @module: module which will be the owner of the driver
1006  *
1007  * Use this in legacy-style modules that probe hardware directly and
1008  * register a single platform device and corresponding platform driver.
1009  *
1010  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
1011  */
1012 struct platform_device * __init_or_module __platform_create_bundle(
1013 			struct platform_driver *driver,
1014 			int (*probe)(struct platform_device *),
1015 			struct resource *res, unsigned int n_res,
1016 			const void *data, size_t size, struct module *module)
1017 {
1018 	struct platform_device *pdev;
1019 	int error;
1020 
1021 	pdev = platform_device_alloc(driver->driver.name, -1);
1022 	if (!pdev) {
1023 		error = -ENOMEM;
1024 		goto err_out;
1025 	}
1026 
1027 	error = platform_device_add_resources(pdev, res, n_res);
1028 	if (error)
1029 		goto err_pdev_put;
1030 
1031 	error = platform_device_add_data(pdev, data, size);
1032 	if (error)
1033 		goto err_pdev_put;
1034 
1035 	error = platform_device_add(pdev);
1036 	if (error)
1037 		goto err_pdev_put;
1038 
1039 	error = __platform_driver_probe(driver, probe, module);
1040 	if (error)
1041 		goto err_pdev_del;
1042 
1043 	return pdev;
1044 
1045 err_pdev_del:
1046 	platform_device_del(pdev);
1047 err_pdev_put:
1048 	platform_device_put(pdev);
1049 err_out:
1050 	return ERR_PTR(error);
1051 }
1052 EXPORT_SYMBOL_GPL(__platform_create_bundle);
1053 
1054 /**
1055  * __platform_register_drivers - register an array of platform drivers
1056  * @drivers: an array of drivers to register
1057  * @count: the number of drivers to register
1058  * @owner: module owning the drivers
1059  *
1060  * Registers platform drivers specified by an array. On failure to register a
1061  * driver, all previously registered drivers will be unregistered. Callers of
1062  * this API should use platform_unregister_drivers() to unregister drivers in
1063  * the reverse order.
1064  *
1065  * Returns: 0 on success or a negative error code on failure.
1066  */
1067 int __platform_register_drivers(struct platform_driver * const *drivers,
1068 				unsigned int count, struct module *owner)
1069 {
1070 	unsigned int i;
1071 	int err;
1072 
1073 	for (i = 0; i < count; i++) {
1074 		pr_debug("registering platform driver %ps\n", drivers[i]);
1075 
1076 		err = __platform_driver_register(drivers[i], owner);
1077 		if (err < 0) {
1078 			pr_err("failed to register platform driver %ps: %d\n",
1079 			       drivers[i], err);
1080 			goto error;
1081 		}
1082 	}
1083 
1084 	return 0;
1085 
1086 error:
1087 	while (i--) {
1088 		pr_debug("unregistering platform driver %ps\n", drivers[i]);
1089 		platform_driver_unregister(drivers[i]);
1090 	}
1091 
1092 	return err;
1093 }
1094 EXPORT_SYMBOL_GPL(__platform_register_drivers);
1095 
1096 /**
1097  * platform_unregister_drivers - unregister an array of platform drivers
1098  * @drivers: an array of drivers to unregister
1099  * @count: the number of drivers to unregister
1100  *
1101  * Unregisters platform drivers specified by an array. This is typically used
1102  * to complement an earlier call to platform_register_drivers(). Drivers are
1103  * unregistered in the reverse order in which they were registered.
1104  */
1105 void platform_unregister_drivers(struct platform_driver * const *drivers,
1106 				 unsigned int count)
1107 {
1108 	while (count--) {
1109 		pr_debug("unregistering platform driver %ps\n", drivers[count]);
1110 		platform_driver_unregister(drivers[count]);
1111 	}
1112 }
1113 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
1114 
1115 static const struct platform_device_id *platform_match_id(
1116 			const struct platform_device_id *id,
1117 			struct platform_device *pdev)
1118 {
1119 	while (id->name[0]) {
1120 		if (strcmp(pdev->name, id->name) == 0) {
1121 			pdev->id_entry = id;
1122 			return id;
1123 		}
1124 		id++;
1125 	}
1126 	return NULL;
1127 }
1128 
1129 #ifdef CONFIG_PM_SLEEP
1130 
1131 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1132 {
1133 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1134 	struct platform_device *pdev = to_platform_device(dev);
1135 	int ret = 0;
1136 
1137 	if (dev->driver && pdrv->suspend)
1138 		ret = pdrv->suspend(pdev, mesg);
1139 
1140 	return ret;
1141 }
1142 
1143 static int platform_legacy_resume(struct device *dev)
1144 {
1145 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1146 	struct platform_device *pdev = to_platform_device(dev);
1147 	int ret = 0;
1148 
1149 	if (dev->driver && pdrv->resume)
1150 		ret = pdrv->resume(pdev);
1151 
1152 	return ret;
1153 }
1154 
1155 #endif /* CONFIG_PM_SLEEP */
1156 
1157 #ifdef CONFIG_SUSPEND
1158 
1159 int platform_pm_suspend(struct device *dev)
1160 {
1161 	struct device_driver *drv = dev->driver;
1162 	int ret = 0;
1163 
1164 	if (!drv)
1165 		return 0;
1166 
1167 	if (drv->pm) {
1168 		if (drv->pm->suspend)
1169 			ret = drv->pm->suspend(dev);
1170 	} else {
1171 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1172 	}
1173 
1174 	return ret;
1175 }
1176 
1177 int platform_pm_resume(struct device *dev)
1178 {
1179 	struct device_driver *drv = dev->driver;
1180 	int ret = 0;
1181 
1182 	if (!drv)
1183 		return 0;
1184 
1185 	if (drv->pm) {
1186 		if (drv->pm->resume)
1187 			ret = drv->pm->resume(dev);
1188 	} else {
1189 		ret = platform_legacy_resume(dev);
1190 	}
1191 
1192 	return ret;
1193 }
1194 
1195 #endif /* CONFIG_SUSPEND */
1196 
1197 #ifdef CONFIG_HIBERNATE_CALLBACKS
1198 
1199 int platform_pm_freeze(struct device *dev)
1200 {
1201 	struct device_driver *drv = dev->driver;
1202 	int ret = 0;
1203 
1204 	if (!drv)
1205 		return 0;
1206 
1207 	if (drv->pm) {
1208 		if (drv->pm->freeze)
1209 			ret = drv->pm->freeze(dev);
1210 	} else {
1211 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1212 	}
1213 
1214 	return ret;
1215 }
1216 
1217 int platform_pm_thaw(struct device *dev)
1218 {
1219 	struct device_driver *drv = dev->driver;
1220 	int ret = 0;
1221 
1222 	if (!drv)
1223 		return 0;
1224 
1225 	if (drv->pm) {
1226 		if (drv->pm->thaw)
1227 			ret = drv->pm->thaw(dev);
1228 	} else {
1229 		ret = platform_legacy_resume(dev);
1230 	}
1231 
1232 	return ret;
1233 }
1234 
1235 int platform_pm_poweroff(struct device *dev)
1236 {
1237 	struct device_driver *drv = dev->driver;
1238 	int ret = 0;
1239 
1240 	if (!drv)
1241 		return 0;
1242 
1243 	if (drv->pm) {
1244 		if (drv->pm->poweroff)
1245 			ret = drv->pm->poweroff(dev);
1246 	} else {
1247 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1248 	}
1249 
1250 	return ret;
1251 }
1252 
1253 int platform_pm_restore(struct device *dev)
1254 {
1255 	struct device_driver *drv = dev->driver;
1256 	int ret = 0;
1257 
1258 	if (!drv)
1259 		return 0;
1260 
1261 	if (drv->pm) {
1262 		if (drv->pm->restore)
1263 			ret = drv->pm->restore(dev);
1264 	} else {
1265 		ret = platform_legacy_resume(dev);
1266 	}
1267 
1268 	return ret;
1269 }
1270 
1271 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1272 
1273 /* modalias support enables more hands-off userspace setup:
1274  * (a) environment variable lets new-style hotplug events work once system is
1275  *     fully running:  "modprobe $MODALIAS"
1276  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
1277  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
1278  */
1279 static ssize_t modalias_show(struct device *dev,
1280 			     struct device_attribute *attr, char *buf)
1281 {
1282 	struct platform_device *pdev = to_platform_device(dev);
1283 	int len;
1284 
1285 	len = of_device_modalias(dev, buf, PAGE_SIZE);
1286 	if (len != -ENODEV)
1287 		return len;
1288 
1289 	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
1290 	if (len != -ENODEV)
1291 		return len;
1292 
1293 	return sysfs_emit(buf, "platform:%s\n", pdev->name);
1294 }
1295 static DEVICE_ATTR_RO(modalias);
1296 
1297 static ssize_t numa_node_show(struct device *dev,
1298 			      struct device_attribute *attr, char *buf)
1299 {
1300 	return sysfs_emit(buf, "%d\n", dev_to_node(dev));
1301 }
1302 static DEVICE_ATTR_RO(numa_node);
1303 
1304 static ssize_t driver_override_show(struct device *dev,
1305 				    struct device_attribute *attr, char *buf)
1306 {
1307 	struct platform_device *pdev = to_platform_device(dev);
1308 	ssize_t len;
1309 
1310 	device_lock(dev);
1311 	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
1312 	device_unlock(dev);
1313 
1314 	return len;
1315 }
1316 
1317 static ssize_t driver_override_store(struct device *dev,
1318 				     struct device_attribute *attr,
1319 				     const char *buf, size_t count)
1320 {
1321 	struct platform_device *pdev = to_platform_device(dev);
1322 	char *driver_override, *old, *cp;
1323 
1324 	/* We need to keep extra room for a newline */
1325 	if (count >= (PAGE_SIZE - 1))
1326 		return -EINVAL;
1327 
1328 	driver_override = kstrndup(buf, count, GFP_KERNEL);
1329 	if (!driver_override)
1330 		return -ENOMEM;
1331 
1332 	cp = strchr(driver_override, '\n');
1333 	if (cp)
1334 		*cp = '\0';
1335 
1336 	device_lock(dev);
1337 	old = pdev->driver_override;
1338 	if (strlen(driver_override)) {
1339 		pdev->driver_override = driver_override;
1340 	} else {
1341 		kfree(driver_override);
1342 		pdev->driver_override = NULL;
1343 	}
1344 	device_unlock(dev);
1345 
1346 	kfree(old);
1347 
1348 	return count;
1349 }
1350 static DEVICE_ATTR_RW(driver_override);
1351 
1352 static struct attribute *platform_dev_attrs[] = {
1353 	&dev_attr_modalias.attr,
1354 	&dev_attr_numa_node.attr,
1355 	&dev_attr_driver_override.attr,
1356 	NULL,
1357 };
1358 
1359 static umode_t platform_dev_attrs_visible(struct kobject *kobj, struct attribute *a,
1360 		int n)
1361 {
1362 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
1363 
1364 	if (a == &dev_attr_numa_node.attr &&
1365 			dev_to_node(dev) == NUMA_NO_NODE)
1366 		return 0;
1367 
1368 	return a->mode;
1369 }
1370 
1371 static struct attribute_group platform_dev_group = {
1372 	.attrs = platform_dev_attrs,
1373 	.is_visible = platform_dev_attrs_visible,
1374 };
1375 __ATTRIBUTE_GROUPS(platform_dev);
1376 
1377 
1378 /**
1379  * platform_match - bind platform device to platform driver.
1380  * @dev: device.
1381  * @drv: driver.
1382  *
1383  * Platform device IDs are assumed to be encoded like this:
1384  * "<name><instance>", where <name> is a short description of the type of
1385  * device, like "pci" or "floppy", and <instance> is the enumerated
1386  * instance of the device, like '0' or '42'.  Driver IDs are simply
1387  * "<name>".  So, extract the <name> from the platform_device structure,
1388  * and compare it against the name of the driver. Return whether they match
1389  * or not.
1390  */
1391 static int platform_match(struct device *dev, struct device_driver *drv)
1392 {
1393 	struct platform_device *pdev = to_platform_device(dev);
1394 	struct platform_driver *pdrv = to_platform_driver(drv);
1395 
1396 	/* When driver_override is set, only bind to the matching driver */
1397 	if (pdev->driver_override)
1398 		return !strcmp(pdev->driver_override, drv->name);
1399 
1400 	/* Attempt an OF style match first */
1401 	if (of_driver_match_device(dev, drv))
1402 		return 1;
1403 
1404 	/* Then try ACPI style match */
1405 	if (acpi_driver_match_device(dev, drv))
1406 		return 1;
1407 
1408 	/* Then try to match against the id table */
1409 	if (pdrv->id_table)
1410 		return platform_match_id(pdrv->id_table, pdev) != NULL;
1411 
1412 	/* fall-back to driver name match */
1413 	return (strcmp(pdev->name, drv->name) == 0);
1414 }
1415 
1416 static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
1417 {
1418 	struct platform_device	*pdev = to_platform_device(dev);
1419 	int rc;
1420 
1421 	/* Some devices have extra OF data and an OF-style MODALIAS */
1422 	rc = of_device_uevent_modalias(dev, env);
1423 	if (rc != -ENODEV)
1424 		return rc;
1425 
1426 	rc = acpi_device_uevent_modalias(dev, env);
1427 	if (rc != -ENODEV)
1428 		return rc;
1429 
1430 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1431 			pdev->name);
1432 	return 0;
1433 }
1434 
1435 static int platform_probe(struct device *_dev)
1436 {
1437 	struct platform_driver *drv = to_platform_driver(_dev->driver);
1438 	struct platform_device *dev = to_platform_device(_dev);
1439 	int ret;
1440 
1441 	/*
1442 	 * A driver registered using platform_driver_probe() cannot be bound
1443 	 * again later because the probe function usually lives in __init code
1444 	 * and so is gone. For these drivers .probe is set to
1445 	 * platform_probe_fail in __platform_driver_probe(). Don't even prepare
1446 	 * clocks and PM domains for these to match the traditional behaviour.
1447 	 */
1448 	if (unlikely(drv->probe == platform_probe_fail))
1449 		return -ENXIO;
1450 
1451 	ret = of_clk_set_defaults(_dev->of_node, false);
1452 	if (ret < 0)
1453 		return ret;
1454 
1455 	ret = dev_pm_domain_attach(_dev, true);
1456 	if (ret)
1457 		goto out;
1458 
1459 	if (drv->probe) {
1460 		ret = drv->probe(dev);
1461 		if (ret)
1462 			dev_pm_domain_detach(_dev, true);
1463 	}
1464 
1465 out:
1466 	if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
1467 		dev_warn(_dev, "probe deferral not supported\n");
1468 		ret = -ENXIO;
1469 	}
1470 
1471 	return ret;
1472 }
1473 
1474 static int platform_remove(struct device *_dev)
1475 {
1476 	struct platform_driver *drv = to_platform_driver(_dev->driver);
1477 	struct platform_device *dev = to_platform_device(_dev);
1478 
1479 	if (drv->remove) {
1480 		int ret = drv->remove(dev);
1481 
1482 		if (ret)
1483 			dev_warn(_dev, "remove callback returned a non-zero value. This will be ignored.\n");
1484 	}
1485 	dev_pm_domain_detach(_dev, true);
1486 
1487 	return 0;
1488 }
1489 
1490 static void platform_shutdown(struct device *_dev)
1491 {
1492 	struct platform_device *dev = to_platform_device(_dev);
1493 	struct platform_driver *drv;
1494 
1495 	if (!_dev->driver)
1496 		return;
1497 
1498 	drv = to_platform_driver(_dev->driver);
1499 	if (drv->shutdown)
1500 		drv->shutdown(dev);
1501 }
1502 
1503 
1504 int platform_dma_configure(struct device *dev)
1505 {
1506 	enum dev_dma_attr attr;
1507 	int ret = 0;
1508 
1509 	if (dev->of_node) {
1510 		ret = of_dma_configure(dev, dev->of_node, true);
1511 	} else if (has_acpi_companion(dev)) {
1512 		attr = acpi_get_dma_attr(to_acpi_device_node(dev->fwnode));
1513 		ret = acpi_dma_configure(dev, attr);
1514 	}
1515 
1516 	return ret;
1517 }
1518 
1519 static const struct dev_pm_ops platform_dev_pm_ops = {
1520 	.runtime_suspend = pm_generic_runtime_suspend,
1521 	.runtime_resume = pm_generic_runtime_resume,
1522 	USE_PLATFORM_PM_SLEEP_OPS
1523 };
1524 
1525 struct bus_type platform_bus_type = {
1526 	.name		= "platform",
1527 	.dev_groups	= platform_dev_groups,
1528 	.match		= platform_match,
1529 	.uevent		= platform_uevent,
1530 	.probe		= platform_probe,
1531 	.remove		= platform_remove,
1532 	.shutdown	= platform_shutdown,
1533 	.dma_configure	= platform_dma_configure,
1534 	.pm		= &platform_dev_pm_ops,
1535 };
1536 EXPORT_SYMBOL_GPL(platform_bus_type);
1537 
1538 static inline int __platform_match(struct device *dev, const void *drv)
1539 {
1540 	return platform_match(dev, (struct device_driver *)drv);
1541 }
1542 
1543 /**
1544  * platform_find_device_by_driver - Find a platform device with a given
1545  * driver.
1546  * @start: The device to start the search from.
1547  * @drv: The device driver to look for.
1548  */
1549 struct device *platform_find_device_by_driver(struct device *start,
1550 					      const struct device_driver *drv)
1551 {
1552 	return bus_find_device(&platform_bus_type, start, drv,
1553 			       __platform_match);
1554 }
1555 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1556 
1557 void __weak __init early_platform_cleanup(void) { }
1558 
1559 int __init platform_bus_init(void)
1560 {
1561 	int error;
1562 
1563 	early_platform_cleanup();
1564 
1565 	error = device_register(&platform_bus);
1566 	if (error) {
1567 		put_device(&platform_bus);
1568 		return error;
1569 	}
1570 	error =  bus_register(&platform_bus_type);
1571 	if (error)
1572 		device_unregister(&platform_bus);
1573 	of_platform_register_reconfig_notifier();
1574 	return error;
1575 }
1576