xref: /linux/drivers/base/platform.c (revision d1880d5f5899c572337ceb3d7e067052b22597e1)
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 #include <linux/iommu.h>
34 #include <linux/dma-map-ops.h>
35 
36 #include "base.h"
37 #include "power/power.h"
38 
39 /* For automatically allocated device IDs */
40 static DEFINE_IDA(platform_devid_ida);
41 
42 struct device platform_bus = {
43 	.init_name	= "platform",
44 };
45 EXPORT_SYMBOL_GPL(platform_bus);
46 
47 /**
48  * platform_get_resource - get a resource for a device
49  * @dev: platform device
50  * @type: resource type
51  * @num: resource index
52  *
53  * Return: a pointer to the resource or NULL on failure.
54  */
55 struct resource *platform_get_resource(struct platform_device *dev,
56 				       unsigned int type, unsigned int num)
57 {
58 	u32 i;
59 
60 	for (i = 0; i < dev->num_resources; i++) {
61 		struct resource *r = &dev->resource[i];
62 
63 		if (type == resource_type(r) && num-- == 0)
64 			return r;
65 	}
66 	return NULL;
67 }
68 EXPORT_SYMBOL_GPL(platform_get_resource);
69 
70 struct resource *platform_get_mem_or_io(struct platform_device *dev,
71 					unsigned int num)
72 {
73 	u32 i;
74 
75 	for (i = 0; i < dev->num_resources; i++) {
76 		struct resource *r = &dev->resource[i];
77 
78 		if ((resource_type(r) & (IORESOURCE_MEM | IORESOURCE_IO)) && num-- == 0)
79 			return r;
80 	}
81 	return NULL;
82 }
83 EXPORT_SYMBOL_GPL(platform_get_mem_or_io);
84 
85 #ifdef CONFIG_HAS_IOMEM
86 /**
87  * devm_platform_get_and_ioremap_resource - call devm_ioremap_resource() for a
88  *					    platform device and get resource
89  *
90  * @pdev: platform device to use both for memory resource lookup as well as
91  *        resource management
92  * @index: resource index
93  * @res: optional output parameter to store a pointer to the obtained resource.
94  *
95  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
96  * on failure.
97  */
98 void __iomem *
99 devm_platform_get_and_ioremap_resource(struct platform_device *pdev,
100 				       unsigned int index, struct resource **res)
101 {
102 	struct resource *r;
103 
104 	r = platform_get_resource(pdev, IORESOURCE_MEM, index);
105 	if (res)
106 		*res = r;
107 	return devm_ioremap_resource(&pdev->dev, r);
108 }
109 EXPORT_SYMBOL_GPL(devm_platform_get_and_ioremap_resource);
110 
111 /**
112  * devm_platform_ioremap_resource - call devm_ioremap_resource() for a platform
113  *				    device
114  *
115  * @pdev: platform device to use both for memory resource lookup as well as
116  *        resource management
117  * @index: resource index
118  *
119  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
120  * on failure.
121  */
122 void __iomem *devm_platform_ioremap_resource(struct platform_device *pdev,
123 					     unsigned int index)
124 {
125 	return devm_platform_get_and_ioremap_resource(pdev, index, NULL);
126 }
127 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource);
128 
129 /**
130  * devm_platform_ioremap_resource_byname - call devm_ioremap_resource for
131  *					   a platform device, retrieve the
132  *					   resource by name
133  *
134  * @pdev: platform device to use both for memory resource lookup as well as
135  *	  resource management
136  * @name: name of the resource
137  *
138  * Return: a pointer to the remapped memory or an ERR_PTR() encoded error code
139  * on failure.
140  */
141 void __iomem *
142 devm_platform_ioremap_resource_byname(struct platform_device *pdev,
143 				      const char *name)
144 {
145 	struct resource *res;
146 
147 	res = platform_get_resource_byname(pdev, IORESOURCE_MEM, name);
148 	return devm_ioremap_resource(&pdev->dev, res);
149 }
150 EXPORT_SYMBOL_GPL(devm_platform_ioremap_resource_byname);
151 #endif /* CONFIG_HAS_IOMEM */
152 
153 static const struct cpumask *get_irq_affinity(struct platform_device *dev,
154 					      unsigned int num)
155 {
156 	const struct cpumask *mask = NULL;
157 #ifndef CONFIG_SPARC
158 	struct fwnode_handle *fwnode = dev_fwnode(&dev->dev);
159 
160 	if (is_of_node(fwnode))
161 		mask = of_irq_get_affinity(to_of_node(fwnode), num);
162 	else if (is_acpi_device_node(fwnode))
163 		mask = acpi_irq_get_affinity(ACPI_HANDLE_FWNODE(fwnode), num);
164 #endif
165 
166 	return mask ?: cpu_possible_mask;
167 }
168 
169 /**
170  * platform_get_irq_affinity - get an optional IRQ and its affinity for a device
171  * @dev:	platform device
172  * @num:	interrupt number index
173  * @affinity:	optional cpumask pointer to get the affinity of a per-cpu interrupt
174  *
175  * Gets an interrupt for a platform device. Device drivers should check the
176  * return value for errors so as to not pass a negative integer value to
177  * the request_irq() APIs. Optional affinity information is provided in the
178  * affinity pointer if available, and NULL otherwise.
179  *
180  * Return: non-zero interrupt number on success, negative error number on failure.
181  */
182 int platform_get_irq_affinity(struct platform_device *dev, unsigned int num,
183 			      const struct cpumask **affinity)
184 {
185 	int ret;
186 #ifdef CONFIG_SPARC
187 	/* sparc does not have irqs represented as IORESOURCE_IRQ resources */
188 	if (!dev || num >= dev->archdata.num_irqs)
189 		goto out_not_found;
190 	ret = dev->archdata.irqs[num];
191 	goto out;
192 #else
193 	struct fwnode_handle *fwnode = dev_fwnode(&dev->dev);
194 	struct resource *r;
195 
196 	if (is_of_node(fwnode)) {
197 		ret = of_irq_get(to_of_node(fwnode), num);
198 		if (ret > 0 || ret == -EPROBE_DEFER)
199 			goto out;
200 	}
201 
202 	r = platform_get_resource(dev, IORESOURCE_IRQ, num);
203 	if (is_acpi_device_node(fwnode)) {
204 		if (r && r->flags & IORESOURCE_DISABLED) {
205 			ret = acpi_irq_get(ACPI_HANDLE_FWNODE(fwnode), num, r);
206 			if (ret)
207 				goto out;
208 		}
209 	}
210 
211 	/*
212 	 * The resources may pass trigger flags to the irqs that need
213 	 * to be set up. It so happens that the trigger flags for
214 	 * IORESOURCE_BITS correspond 1-to-1 to the IRQF_TRIGGER*
215 	 * settings.
216 	 */
217 	if (r && r->flags & IORESOURCE_BITS) {
218 		struct irq_data *irqd;
219 
220 		irqd = irq_get_irq_data(r->start);
221 		if (!irqd)
222 			goto out_not_found;
223 		irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS);
224 	}
225 
226 	if (r) {
227 		ret = r->start;
228 		goto out;
229 	}
230 
231 	/*
232 	 * For the index 0 interrupt, allow falling back to GpioInt
233 	 * resources. While a device could have both Interrupt and GpioInt
234 	 * resources, making this fallback ambiguous, in many common cases
235 	 * the device will only expose one IRQ, and this fallback
236 	 * allows a common code path across either kind of resource.
237 	 */
238 	if (num == 0 && is_acpi_device_node(fwnode)) {
239 		ret = acpi_dev_gpio_irq_get(to_acpi_device_node(fwnode), num);
240 		/* Our callers expect -ENXIO for missing IRQs. */
241 		if (ret >= 0 || ret == -EPROBE_DEFER)
242 			goto out;
243 	}
244 
245 #endif
246 out_not_found:
247 	ret = -ENXIO;
248 out:
249 	if (WARN(!ret, "0 is an invalid IRQ number\n"))
250 		return -EINVAL;
251 
252 	if (ret > 0 && affinity)
253 		*affinity = get_irq_affinity(dev, num);
254 
255 	return ret;
256 }
257 EXPORT_SYMBOL_GPL(platform_get_irq_affinity);
258 
259 /**
260  * platform_get_irq_optional - get an optional interrupt for a device
261  * @dev:	platform device
262  * @num:	interrupt number index
263  *
264  * Gets an interrupt for a platform device. Device drivers should check the
265  * return value for errors so as to not pass a negative integer value to
266  * the request_irq() APIs. This is the same as platform_get_irq(), except
267  * that it does not print an error message if an interrupt can not be
268  * obtained.
269  *
270  * For example::
271  *
272  *		int irq = platform_get_irq_optional(pdev, 0);
273  *		if (irq < 0)
274  *			return irq;
275  *
276  * Return: non-zero interrupt number on success, negative error number on failure.
277  */
278 int platform_get_irq_optional(struct platform_device *dev, unsigned int num)
279 {
280 	return platform_get_irq_affinity(dev, num, NULL);
281 }
282 EXPORT_SYMBOL_GPL(platform_get_irq_optional);
283 
284 /**
285  * platform_get_irq - get an IRQ for a device
286  * @dev: platform device
287  * @num: IRQ number index
288  *
289  * Gets an IRQ for a platform device and prints an error message if finding the
290  * IRQ fails. Device drivers should check the return value for errors so as to
291  * not pass a negative integer value to the request_irq() APIs.
292  *
293  * For example::
294  *
295  *		int irq = platform_get_irq(pdev, 0);
296  *		if (irq < 0)
297  *			return irq;
298  *
299  * Return: non-zero IRQ number on success, negative error number on failure.
300  */
301 int platform_get_irq(struct platform_device *dev, unsigned int num)
302 {
303 	int ret;
304 
305 	ret = platform_get_irq_optional(dev, num);
306 	if (ret < 0)
307 		return dev_err_probe(&dev->dev, ret,
308 				     "IRQ index %u not found\n", num);
309 
310 	return ret;
311 }
312 EXPORT_SYMBOL_GPL(platform_get_irq);
313 
314 /**
315  * platform_irq_count - Count the number of IRQs a platform device uses
316  * @dev: platform device
317  *
318  * Return: Number of IRQs a platform device uses or EPROBE_DEFER
319  */
320 int platform_irq_count(struct platform_device *dev)
321 {
322 	int ret, nr = 0;
323 
324 	while ((ret = platform_get_irq_optional(dev, nr)) >= 0)
325 		nr++;
326 
327 	if (ret == -EPROBE_DEFER)
328 		return ret;
329 
330 	return nr;
331 }
332 EXPORT_SYMBOL_GPL(platform_irq_count);
333 
334 struct irq_affinity_devres {
335 	unsigned int count;
336 	unsigned int irq[] __counted_by(count);
337 };
338 
339 static void platform_disable_acpi_irq(struct platform_device *pdev, int index)
340 {
341 	struct resource *r;
342 
343 	r = platform_get_resource(pdev, IORESOURCE_IRQ, index);
344 	if (r)
345 		irqresource_disabled(r, 0);
346 }
347 
348 static void devm_platform_get_irqs_affinity_release(struct device *dev,
349 						    void *res)
350 {
351 	struct irq_affinity_devres *ptr = res;
352 	int i;
353 
354 	for (i = 0; i < ptr->count; i++) {
355 		irq_dispose_mapping(ptr->irq[i]);
356 
357 		if (is_acpi_device_node(dev_fwnode(dev)))
358 			platform_disable_acpi_irq(to_platform_device(dev), i);
359 	}
360 }
361 
362 /**
363  * devm_platform_get_irqs_affinity - devm method to get a set of IRQs for a
364  *				device using an interrupt affinity descriptor
365  * @dev: platform device pointer
366  * @affd: affinity descriptor
367  * @minvec: minimum count of interrupt vectors
368  * @maxvec: maximum count of interrupt vectors
369  * @irqs: pointer holder for IRQ numbers
370  *
371  * Gets a set of IRQs for a platform device, and updates IRQ afffinty according
372  * to the passed affinity descriptor
373  *
374  * Return: Number of vectors on success, negative error number on failure.
375  */
376 int devm_platform_get_irqs_affinity(struct platform_device *dev,
377 				    struct irq_affinity *affd,
378 				    unsigned int minvec,
379 				    unsigned int maxvec,
380 				    int **irqs)
381 {
382 	struct irq_affinity_devres *ptr;
383 	struct irq_affinity_desc *desc;
384 	size_t size;
385 	int i, ret, nvec;
386 
387 	if (!affd)
388 		return -EPERM;
389 
390 	if (maxvec < minvec)
391 		return -ERANGE;
392 
393 	nvec = platform_irq_count(dev);
394 	if (nvec < 0)
395 		return nvec;
396 
397 	if (nvec < minvec)
398 		return -ENOSPC;
399 
400 	nvec = irq_calc_affinity_vectors(minvec, nvec, affd);
401 	if (nvec < minvec)
402 		return -ENOSPC;
403 
404 	if (nvec > maxvec)
405 		nvec = maxvec;
406 
407 	size = sizeof(*ptr) + sizeof(unsigned int) * nvec;
408 	ptr = devres_alloc(devm_platform_get_irqs_affinity_release, size,
409 			   GFP_KERNEL);
410 	if (!ptr)
411 		return -ENOMEM;
412 
413 	ptr->count = nvec;
414 
415 	for (i = 0; i < nvec; i++) {
416 		int irq = platform_get_irq(dev, i);
417 		if (irq < 0) {
418 			ret = irq;
419 			goto err_free_devres;
420 		}
421 		ptr->irq[i] = irq;
422 	}
423 
424 	desc = irq_create_affinity_masks(nvec, affd);
425 	if (!desc) {
426 		ret = -ENOMEM;
427 		goto err_free_devres;
428 	}
429 
430 	for (i = 0; i < nvec; i++) {
431 		ret = irq_update_affinity_desc(ptr->irq[i], &desc[i]);
432 		if (ret) {
433 			dev_err(&dev->dev, "failed to update irq%d affinity descriptor (%d)\n",
434 				ptr->irq[i], ret);
435 			goto err_free_desc;
436 		}
437 	}
438 
439 	devres_add(&dev->dev, ptr);
440 
441 	kfree(desc);
442 
443 	*irqs = ptr->irq;
444 
445 	return nvec;
446 
447 err_free_desc:
448 	kfree(desc);
449 err_free_devres:
450 	devres_free(ptr);
451 	return ret;
452 }
453 EXPORT_SYMBOL_GPL(devm_platform_get_irqs_affinity);
454 
455 /**
456  * platform_get_resource_byname - get a resource for a device by name
457  * @dev: platform device
458  * @type: resource type
459  * @name: resource name
460  */
461 struct resource *platform_get_resource_byname(struct platform_device *dev,
462 					      unsigned int type,
463 					      const char *name)
464 {
465 	u32 i;
466 
467 	for (i = 0; i < dev->num_resources; i++) {
468 		struct resource *r = &dev->resource[i];
469 
470 		if (unlikely(!r->name))
471 			continue;
472 
473 		if (type == resource_type(r) && !strcmp(r->name, name))
474 			return r;
475 	}
476 	return NULL;
477 }
478 EXPORT_SYMBOL_GPL(platform_get_resource_byname);
479 
480 static int __platform_get_irq_byname(struct platform_device *dev,
481 				     const char *name)
482 {
483 	struct resource *r;
484 	int ret;
485 
486 	ret = fwnode_irq_get_byname(dev_fwnode(&dev->dev), name);
487 	if (ret > 0 || ret == -EPROBE_DEFER)
488 		return ret;
489 
490 	r = platform_get_resource_byname(dev, IORESOURCE_IRQ, name);
491 	if (r) {
492 		if (WARN(!r->start, "0 is an invalid IRQ number\n"))
493 			return -EINVAL;
494 		return r->start;
495 	}
496 
497 	return -ENXIO;
498 }
499 
500 /**
501  * platform_get_irq_byname - get an IRQ for a device by name
502  * @dev: platform device
503  * @name: IRQ name
504  *
505  * Get an IRQ like platform_get_irq(), but then by name rather then by index.
506  *
507  * Return: non-zero IRQ number on success, negative error number on failure.
508  */
509 int platform_get_irq_byname(struct platform_device *dev, const char *name)
510 {
511 	int ret;
512 
513 	ret = __platform_get_irq_byname(dev, name);
514 	if (ret < 0)
515 		return dev_err_probe(&dev->dev, ret, "IRQ %s not found\n",
516 				     name);
517 	return ret;
518 }
519 EXPORT_SYMBOL_GPL(platform_get_irq_byname);
520 
521 /**
522  * platform_get_irq_byname_optional - get an optional IRQ for a device by name
523  * @dev: platform device
524  * @name: IRQ name
525  *
526  * Get an optional IRQ by name like platform_get_irq_byname(). Except that it
527  * does not print an error message if an IRQ can not be obtained.
528  *
529  * Return: non-zero IRQ number on success, negative error number on failure.
530  */
531 int platform_get_irq_byname_optional(struct platform_device *dev,
532 				     const char *name)
533 {
534 	return __platform_get_irq_byname(dev, name);
535 }
536 EXPORT_SYMBOL_GPL(platform_get_irq_byname_optional);
537 
538 /**
539  * platform_add_devices - add a numbers of platform devices
540  * @devs: array of platform devices to add
541  * @num: number of platform devices in array
542  *
543  * Return: 0 on success, negative error number on failure.
544  */
545 int platform_add_devices(struct platform_device **devs, int num)
546 {
547 	int i, ret = 0;
548 
549 	for (i = 0; i < num; i++) {
550 		ret = platform_device_register(devs[i]);
551 		if (ret) {
552 			while (--i >= 0)
553 				platform_device_unregister(devs[i]);
554 			break;
555 		}
556 	}
557 
558 	return ret;
559 }
560 EXPORT_SYMBOL_GPL(platform_add_devices);
561 
562 struct platform_object {
563 	struct platform_device pdev;
564 	char name[];
565 };
566 
567 /*
568  * Set up default DMA mask for platform devices if the they weren't
569  * previously set by the architecture / DT.
570  */
571 static void setup_pdev_dma_masks(struct platform_device *pdev)
572 {
573 	pdev->dev.dma_parms = &pdev->dma_parms;
574 
575 	if (!pdev->dev.coherent_dma_mask)
576 		pdev->dev.coherent_dma_mask = DMA_BIT_MASK(32);
577 	if (!pdev->dev.dma_mask) {
578 		pdev->platform_dma_mask = DMA_BIT_MASK(32);
579 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
580 	}
581 };
582 
583 /**
584  * platform_device_put - destroy a platform device
585  * @pdev: platform device to free
586  *
587  * Free all memory associated with a platform device.  This function must
588  * _only_ be externally called in error cases.  All other usage is a bug.
589  */
590 void platform_device_put(struct platform_device *pdev)
591 {
592 	if (!IS_ERR_OR_NULL(pdev))
593 		put_device(&pdev->dev);
594 }
595 EXPORT_SYMBOL_GPL(platform_device_put);
596 
597 static void platform_device_release(struct device *dev)
598 {
599 	struct platform_object *pa = container_of(dev, struct platform_object,
600 						  pdev.dev);
601 
602 	of_node_put(pa->pdev.dev.of_node);
603 	kfree(pa->pdev.dev.platform_data);
604 	kfree(pa->pdev.mfd_cell);
605 	kfree(pa->pdev.resource);
606 	kfree(pa->pdev.driver_override);
607 	kfree(pa);
608 }
609 
610 /**
611  * platform_device_alloc - create a platform device
612  * @name: base name of the device we're adding
613  * @id: instance id
614  *
615  * Create a platform device object which can have other objects attached
616  * to it, and which will have attached objects freed when it is released.
617  */
618 struct platform_device *platform_device_alloc(const char *name, int id)
619 {
620 	struct platform_object *pa;
621 
622 	pa = kzalloc(sizeof(*pa) + strlen(name) + 1, GFP_KERNEL);
623 	if (pa) {
624 		strcpy(pa->name, name);
625 		pa->pdev.name = pa->name;
626 		pa->pdev.id = id;
627 		device_initialize(&pa->pdev.dev);
628 		pa->pdev.dev.release = platform_device_release;
629 		setup_pdev_dma_masks(&pa->pdev);
630 	}
631 
632 	return pa ? &pa->pdev : NULL;
633 }
634 EXPORT_SYMBOL_GPL(platform_device_alloc);
635 
636 /**
637  * platform_device_add_resources - add resources to a platform device
638  * @pdev: platform device allocated by platform_device_alloc to add resources to
639  * @res: set of resources that needs to be allocated for the device
640  * @num: number of resources
641  *
642  * Add a copy of the resources to the platform device.  The memory
643  * associated with the resources will be freed when the platform device is
644  * released.
645  */
646 int platform_device_add_resources(struct platform_device *pdev,
647 				  const struct resource *res, unsigned int num)
648 {
649 	struct resource *r = NULL;
650 
651 	if (res) {
652 		r = kmemdup_array(res, num, sizeof(*r), GFP_KERNEL);
653 		if (!r)
654 			return -ENOMEM;
655 	}
656 
657 	kfree(pdev->resource);
658 	pdev->resource = r;
659 	pdev->num_resources = num;
660 	return 0;
661 }
662 EXPORT_SYMBOL_GPL(platform_device_add_resources);
663 
664 /**
665  * platform_device_add_data - add platform-specific data to a platform device
666  * @pdev: platform device allocated by platform_device_alloc to add resources to
667  * @data: platform specific data for this platform device
668  * @size: size of platform specific data
669  *
670  * Add a copy of platform specific data to the platform device's
671  * platform_data pointer.  The memory associated with the platform data
672  * will be freed when the platform device is released.
673  */
674 int platform_device_add_data(struct platform_device *pdev, const void *data,
675 			     size_t size)
676 {
677 	void *d = NULL;
678 
679 	if (data) {
680 		d = kmemdup(data, size, GFP_KERNEL);
681 		if (!d)
682 			return -ENOMEM;
683 	}
684 
685 	kfree(pdev->dev.platform_data);
686 	pdev->dev.platform_data = d;
687 	return 0;
688 }
689 EXPORT_SYMBOL_GPL(platform_device_add_data);
690 
691 /**
692  * platform_device_add - add a platform device to device hierarchy
693  * @pdev: platform device we're adding
694  *
695  * This is part 2 of platform_device_register(), though may be called
696  * separately _iff_ pdev was allocated by platform_device_alloc().
697  */
698 int platform_device_add(struct platform_device *pdev)
699 {
700 	struct device *dev = &pdev->dev;
701 	u32 i;
702 	int ret;
703 
704 	if (!dev->parent)
705 		dev->parent = &platform_bus;
706 
707 	dev->bus = &platform_bus_type;
708 
709 	switch (pdev->id) {
710 	default:
711 		dev_set_name(dev, "%s.%d", pdev->name,  pdev->id);
712 		break;
713 	case PLATFORM_DEVID_NONE:
714 		dev_set_name(dev, "%s", pdev->name);
715 		break;
716 	case PLATFORM_DEVID_AUTO:
717 		/*
718 		 * Automatically allocated device ID. We mark it as such so
719 		 * that we remember it must be freed, and we append a suffix
720 		 * to avoid namespace collision with explicit IDs.
721 		 */
722 		ret = ida_alloc(&platform_devid_ida, GFP_KERNEL);
723 		if (ret < 0)
724 			return ret;
725 		pdev->id = ret;
726 		pdev->id_auto = true;
727 		dev_set_name(dev, "%s.%d.auto", pdev->name, pdev->id);
728 		break;
729 	}
730 
731 	for (i = 0; i < pdev->num_resources; i++) {
732 		struct resource *p, *r = &pdev->resource[i];
733 
734 		if (r->name == NULL)
735 			r->name = dev_name(dev);
736 
737 		p = r->parent;
738 		if (!p) {
739 			if (resource_type(r) == IORESOURCE_MEM)
740 				p = &iomem_resource;
741 			else if (resource_type(r) == IORESOURCE_IO)
742 				p = &ioport_resource;
743 		}
744 
745 		if (p) {
746 			ret = insert_resource(p, r);
747 			if (ret) {
748 				dev_err(dev, "failed to claim resource %d: %pR\n", i, r);
749 				goto failed;
750 			}
751 		}
752 	}
753 
754 	pr_debug("Registering platform device '%s'. Parent at %s\n", dev_name(dev),
755 		 dev_name(dev->parent));
756 
757 	ret = device_add(dev);
758 	if (ret)
759 		goto failed;
760 
761 	return 0;
762 
763  failed:
764 	if (pdev->id_auto) {
765 		ida_free(&platform_devid_ida, pdev->id);
766 		pdev->id = PLATFORM_DEVID_AUTO;
767 	}
768 
769 	while (i--) {
770 		struct resource *r = &pdev->resource[i];
771 		if (r->parent)
772 			release_resource(r);
773 	}
774 
775 	return ret;
776 }
777 EXPORT_SYMBOL_GPL(platform_device_add);
778 
779 /**
780  * platform_device_del - remove a platform-level device
781  * @pdev: platform device we're removing
782  *
783  * Note that this function will also release all memory- and port-based
784  * resources owned by the device (@dev->resource).  This function must
785  * _only_ be externally called in error cases.  All other usage is a bug.
786  */
787 void platform_device_del(struct platform_device *pdev)
788 {
789 	u32 i;
790 
791 	if (!IS_ERR_OR_NULL(pdev)) {
792 		device_del(&pdev->dev);
793 
794 		if (pdev->id_auto) {
795 			ida_free(&platform_devid_ida, pdev->id);
796 			pdev->id = PLATFORM_DEVID_AUTO;
797 		}
798 
799 		for (i = 0; i < pdev->num_resources; i++) {
800 			struct resource *r = &pdev->resource[i];
801 			if (r->parent)
802 				release_resource(r);
803 		}
804 	}
805 }
806 EXPORT_SYMBOL_GPL(platform_device_del);
807 
808 /**
809  * platform_device_register - add a platform-level device
810  * @pdev: platform device we're adding
811  *
812  * NOTE: _Never_ directly free @pdev after calling this function, even if it
813  * returned an error! Always use platform_device_put() to give up the
814  * reference initialised in this function instead.
815  */
816 int platform_device_register(struct platform_device *pdev)
817 {
818 	device_initialize(&pdev->dev);
819 	setup_pdev_dma_masks(pdev);
820 	return platform_device_add(pdev);
821 }
822 EXPORT_SYMBOL_GPL(platform_device_register);
823 
824 /**
825  * platform_device_unregister - unregister a platform-level device
826  * @pdev: platform device we're unregistering
827  *
828  * Unregistration is done in 2 steps. First we release all resources
829  * and remove it from the subsystem, then we drop reference count by
830  * calling platform_device_put().
831  */
832 void platform_device_unregister(struct platform_device *pdev)
833 {
834 	platform_device_del(pdev);
835 	platform_device_put(pdev);
836 }
837 EXPORT_SYMBOL_GPL(platform_device_unregister);
838 
839 /**
840  * platform_device_register_full - add a platform-level device with
841  * resources and platform-specific data
842  *
843  * @pdevinfo: data used to create device
844  *
845  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
846  */
847 struct platform_device *platform_device_register_full(const struct platform_device_info *pdevinfo)
848 {
849 	int ret;
850 	struct platform_device *pdev;
851 
852 	if (pdevinfo->swnode && pdevinfo->properties)
853 		return ERR_PTR(-EINVAL);
854 
855 	pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
856 	if (!pdev)
857 		return ERR_PTR(-ENOMEM);
858 
859 	pdev->dev.parent = pdevinfo->parent;
860 	pdev->dev.fwnode = pdevinfo->fwnode;
861 	pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
862 	pdev->dev.of_node_reused = pdevinfo->of_node_reused;
863 
864 	if (pdevinfo->dma_mask) {
865 		pdev->platform_dma_mask = pdevinfo->dma_mask;
866 		pdev->dev.dma_mask = &pdev->platform_dma_mask;
867 		pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
868 	}
869 
870 	ret = platform_device_add_resources(pdev, pdevinfo->res, pdevinfo->num_res);
871 	if (ret)
872 		goto err;
873 
874 	ret = platform_device_add_data(pdev, pdevinfo->data, pdevinfo->size_data);
875 	if (ret)
876 		goto err;
877 
878 	if (pdevinfo->swnode) {
879 		ret = device_add_software_node(&pdev->dev, pdevinfo->swnode);
880 		if (ret)
881 			goto err;
882 	} else if (pdevinfo->properties) {
883 		ret = device_create_managed_software_node(&pdev->dev,
884 							  pdevinfo->properties, NULL);
885 		if (ret)
886 			goto err;
887 	}
888 
889 	ret = platform_device_add(pdev);
890 	if (ret) {
891 err:
892 		ACPI_COMPANION_SET(&pdev->dev, NULL);
893 		platform_device_put(pdev);
894 		return ERR_PTR(ret);
895 	}
896 
897 	return pdev;
898 }
899 EXPORT_SYMBOL_GPL(platform_device_register_full);
900 
901 /**
902  * __platform_driver_register - register a driver for platform-level devices
903  * @drv: platform driver structure
904  * @owner: owning module/driver
905  */
906 int __platform_driver_register(struct platform_driver *drv, struct module *owner)
907 {
908 	drv->driver.owner = owner;
909 	drv->driver.bus = &platform_bus_type;
910 
911 	return driver_register(&drv->driver);
912 }
913 EXPORT_SYMBOL_GPL(__platform_driver_register);
914 
915 /**
916  * platform_driver_unregister - unregister a driver for platform-level devices
917  * @drv: platform driver structure
918  */
919 void platform_driver_unregister(struct platform_driver *drv)
920 {
921 	driver_unregister(&drv->driver);
922 }
923 EXPORT_SYMBOL_GPL(platform_driver_unregister);
924 
925 static int platform_probe_fail(struct platform_device *pdev)
926 {
927 	return -ENXIO;
928 }
929 
930 static int is_bound_to_driver(struct device *dev, void *driver)
931 {
932 	if (dev->driver == driver)
933 		return 1;
934 	return 0;
935 }
936 
937 /**
938  * __platform_driver_probe - register driver for non-hotpluggable device
939  * @drv: platform driver structure
940  * @probe: the driver probe routine, probably from an __init section
941  * @module: module which will be the owner of the driver
942  *
943  * Use this instead of platform_driver_register() when you know the device
944  * is not hotpluggable and has already been registered, and you want to
945  * remove its run-once probe() infrastructure from memory after the driver
946  * has bound to the device.
947  *
948  * One typical use for this would be with drivers for controllers integrated
949  * into system-on-chip processors, where the controller devices have been
950  * configured as part of board setup.
951  *
952  * Note that this is incompatible with deferred probing.
953  *
954  * Returns zero if the driver registered and bound to a device, else returns
955  * a negative error code and with the driver not registered.
956  */
957 int __init_or_module __platform_driver_probe(struct platform_driver *drv,
958 					     int (*probe)(struct platform_device *),
959 					     struct module *module)
960 {
961 	int retval;
962 
963 	if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
964 		pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
965 		       drv->driver.name, __func__);
966 		return -EINVAL;
967 	}
968 
969 	/*
970 	 * We have to run our probes synchronously because we check if
971 	 * we find any devices to bind to and exit with error if there
972 	 * are any.
973 	 */
974 	drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
975 
976 	/*
977 	 * Prevent driver from requesting probe deferral to avoid further
978 	 * futile probe attempts.
979 	 */
980 	drv->prevent_deferred_probe = true;
981 
982 	/* make sure driver won't have bind/unbind attributes */
983 	drv->driver.suppress_bind_attrs = true;
984 
985 	/* temporary section violation during probe() */
986 	drv->probe = probe;
987 	retval = __platform_driver_register(drv, module);
988 	if (retval)
989 		return retval;
990 
991 	/* Force all new probes of this driver to fail */
992 	drv->probe = platform_probe_fail;
993 
994 	/* Walk all platform devices and see if any actually bound to this driver.
995 	 * If not, return an error as the device should have done so by now.
996 	 */
997 	if (!bus_for_each_dev(&platform_bus_type, NULL, &drv->driver, is_bound_to_driver)) {
998 		retval = -ENODEV;
999 		platform_driver_unregister(drv);
1000 	}
1001 
1002 	return retval;
1003 }
1004 EXPORT_SYMBOL_GPL(__platform_driver_probe);
1005 
1006 /**
1007  * __platform_create_bundle - register driver and create corresponding device
1008  * @driver: platform driver structure
1009  * @probe: the driver probe routine, probably from an __init section
1010  * @res: set of resources that needs to be allocated for the device
1011  * @n_res: number of resources
1012  * @data: platform specific data for this platform device
1013  * @size: size of platform specific data
1014  * @module: module which will be the owner of the driver
1015  *
1016  * Use this in legacy-style modules that probe hardware directly and
1017  * register a single platform device and corresponding platform driver.
1018  *
1019  * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
1020  */
1021 struct platform_device * __init_or_module
1022 __platform_create_bundle(struct platform_driver *driver,
1023 			 int (*probe)(struct platform_device *),
1024 			 struct resource *res, unsigned int n_res,
1025 			 const void *data, size_t size, struct module *module)
1026 {
1027 	struct platform_device *pdev;
1028 	int error;
1029 
1030 	pdev = platform_device_alloc(driver->driver.name, PLATFORM_DEVID_NONE);
1031 	if (!pdev) {
1032 		error = -ENOMEM;
1033 		goto err_out;
1034 	}
1035 
1036 	error = platform_device_add_resources(pdev, res, n_res);
1037 	if (error)
1038 		goto err_pdev_put;
1039 
1040 	error = platform_device_add_data(pdev, data, size);
1041 	if (error)
1042 		goto err_pdev_put;
1043 
1044 	error = platform_device_add(pdev);
1045 	if (error)
1046 		goto err_pdev_put;
1047 
1048 	error = __platform_driver_probe(driver, probe, module);
1049 	if (error)
1050 		goto err_pdev_del;
1051 
1052 	return pdev;
1053 
1054 err_pdev_del:
1055 	platform_device_del(pdev);
1056 err_pdev_put:
1057 	platform_device_put(pdev);
1058 err_out:
1059 	return ERR_PTR(error);
1060 }
1061 EXPORT_SYMBOL_GPL(__platform_create_bundle);
1062 
1063 /**
1064  * __platform_register_drivers - register an array of platform drivers
1065  * @drivers: an array of drivers to register
1066  * @count: the number of drivers to register
1067  * @owner: module owning the drivers
1068  *
1069  * Registers platform drivers specified by an array. On failure to register a
1070  * driver, all previously registered drivers will be unregistered. Callers of
1071  * this API should use platform_unregister_drivers() to unregister drivers in
1072  * the reverse order.
1073  *
1074  * Returns: 0 on success or a negative error code on failure.
1075  */
1076 int __platform_register_drivers(struct platform_driver * const *drivers,
1077 				unsigned int count, struct module *owner)
1078 {
1079 	unsigned int i;
1080 	int err;
1081 
1082 	for (i = 0; i < count; i++) {
1083 		pr_debug("registering platform driver %ps\n", drivers[i]);
1084 
1085 		err = __platform_driver_register(drivers[i], owner);
1086 		if (err < 0) {
1087 			pr_err("failed to register platform driver %ps: %d\n",
1088 			       drivers[i], err);
1089 			goto error;
1090 		}
1091 	}
1092 
1093 	return 0;
1094 
1095 error:
1096 	while (i--) {
1097 		pr_debug("unregistering platform driver %ps\n", drivers[i]);
1098 		platform_driver_unregister(drivers[i]);
1099 	}
1100 
1101 	return err;
1102 }
1103 EXPORT_SYMBOL_GPL(__platform_register_drivers);
1104 
1105 /**
1106  * platform_unregister_drivers - unregister an array of platform drivers
1107  * @drivers: an array of drivers to unregister
1108  * @count: the number of drivers to unregister
1109  *
1110  * Unregisters platform drivers specified by an array. This is typically used
1111  * to complement an earlier call to platform_register_drivers(). Drivers are
1112  * unregistered in the reverse order in which they were registered.
1113  */
1114 void platform_unregister_drivers(struct platform_driver * const *drivers,
1115 				 unsigned int count)
1116 {
1117 	while (count--) {
1118 		pr_debug("unregistering platform driver %ps\n", drivers[count]);
1119 		platform_driver_unregister(drivers[count]);
1120 	}
1121 }
1122 EXPORT_SYMBOL_GPL(platform_unregister_drivers);
1123 
1124 static const struct platform_device_id *
1125 platform_match_id(const struct platform_device_id *id, struct platform_device *pdev)
1126 {
1127 	while (id->name[0]) {
1128 		if (strcmp(pdev->name, id->name) == 0) {
1129 			pdev->id_entry = id;
1130 			return id;
1131 		}
1132 		id++;
1133 	}
1134 	return NULL;
1135 }
1136 
1137 #ifdef CONFIG_PM_SLEEP
1138 
1139 static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1140 {
1141 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1142 	struct platform_device *pdev = to_platform_device(dev);
1143 	int ret = 0;
1144 
1145 	if (dev->driver && pdrv->suspend)
1146 		ret = pdrv->suspend(pdev, mesg);
1147 
1148 	return ret;
1149 }
1150 
1151 static int platform_legacy_resume(struct device *dev)
1152 {
1153 	struct platform_driver *pdrv = to_platform_driver(dev->driver);
1154 	struct platform_device *pdev = to_platform_device(dev);
1155 	int ret = 0;
1156 
1157 	if (dev->driver && pdrv->resume)
1158 		ret = pdrv->resume(pdev);
1159 
1160 	return ret;
1161 }
1162 
1163 #endif /* CONFIG_PM_SLEEP */
1164 
1165 #ifdef CONFIG_SUSPEND
1166 
1167 int platform_pm_suspend(struct device *dev)
1168 {
1169 	const struct device_driver *drv = dev->driver;
1170 	int ret = 0;
1171 
1172 	if (!drv)
1173 		return 0;
1174 
1175 	if (drv->pm) {
1176 		if (drv->pm->suspend)
1177 			ret = drv->pm->suspend(dev);
1178 	} else {
1179 		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1180 	}
1181 
1182 	return ret;
1183 }
1184 
1185 int platform_pm_resume(struct device *dev)
1186 {
1187 	const struct device_driver *drv = dev->driver;
1188 	int ret = 0;
1189 
1190 	if (!drv)
1191 		return 0;
1192 
1193 	if (drv->pm) {
1194 		if (drv->pm->resume)
1195 			ret = drv->pm->resume(dev);
1196 	} else {
1197 		ret = platform_legacy_resume(dev);
1198 	}
1199 
1200 	return ret;
1201 }
1202 
1203 #endif /* CONFIG_SUSPEND */
1204 
1205 #ifdef CONFIG_HIBERNATE_CALLBACKS
1206 
1207 int platform_pm_freeze(struct device *dev)
1208 {
1209 	const struct device_driver *drv = dev->driver;
1210 	int ret = 0;
1211 
1212 	if (!drv)
1213 		return 0;
1214 
1215 	if (drv->pm) {
1216 		if (drv->pm->freeze)
1217 			ret = drv->pm->freeze(dev);
1218 	} else {
1219 		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1220 	}
1221 
1222 	return ret;
1223 }
1224 
1225 int platform_pm_thaw(struct device *dev)
1226 {
1227 	const struct device_driver *drv = dev->driver;
1228 	int ret = 0;
1229 
1230 	if (!drv)
1231 		return 0;
1232 
1233 	if (drv->pm) {
1234 		if (drv->pm->thaw)
1235 			ret = drv->pm->thaw(dev);
1236 	} else {
1237 		ret = platform_legacy_resume(dev);
1238 	}
1239 
1240 	return ret;
1241 }
1242 
1243 int platform_pm_poweroff(struct device *dev)
1244 {
1245 	const struct device_driver *drv = dev->driver;
1246 	int ret = 0;
1247 
1248 	if (!drv)
1249 		return 0;
1250 
1251 	if (drv->pm) {
1252 		if (drv->pm->poweroff)
1253 			ret = drv->pm->poweroff(dev);
1254 	} else {
1255 		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1256 	}
1257 
1258 	return ret;
1259 }
1260 
1261 int platform_pm_restore(struct device *dev)
1262 {
1263 	const struct device_driver *drv = dev->driver;
1264 	int ret = 0;
1265 
1266 	if (!drv)
1267 		return 0;
1268 
1269 	if (drv->pm) {
1270 		if (drv->pm->restore)
1271 			ret = drv->pm->restore(dev);
1272 	} else {
1273 		ret = platform_legacy_resume(dev);
1274 	}
1275 
1276 	return ret;
1277 }
1278 
1279 #endif /* CONFIG_HIBERNATE_CALLBACKS */
1280 
1281 /* modalias support enables more hands-off userspace setup:
1282  * (a) environment variable lets new-style hotplug events work once system is
1283  *     fully running:  "modprobe $MODALIAS"
1284  * (b) sysfs attribute lets new-style coldplug recover from hotplug events
1285  *     mishandled before system is fully running:  "modprobe $(cat modalias)"
1286  */
1287 static ssize_t modalias_show(struct device *dev,
1288 			     struct device_attribute *attr, char *buf)
1289 {
1290 	struct platform_device *pdev = to_platform_device(dev);
1291 	int len;
1292 
1293 	len = of_device_modalias(dev, buf, PAGE_SIZE);
1294 	if (len != -ENODEV)
1295 		return len;
1296 
1297 	len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
1298 	if (len != -ENODEV)
1299 		return len;
1300 
1301 	return sysfs_emit(buf, "platform:%s\n", pdev->name);
1302 }
1303 static DEVICE_ATTR_RO(modalias);
1304 
1305 static ssize_t numa_node_show(struct device *dev,
1306 			      struct device_attribute *attr, char *buf)
1307 {
1308 	return sysfs_emit(buf, "%d\n", dev_to_node(dev));
1309 }
1310 static DEVICE_ATTR_RO(numa_node);
1311 
1312 static ssize_t driver_override_show(struct device *dev,
1313 				    struct device_attribute *attr, char *buf)
1314 {
1315 	struct platform_device *pdev = to_platform_device(dev);
1316 	ssize_t len;
1317 
1318 	device_lock(dev);
1319 	len = sysfs_emit(buf, "%s\n", pdev->driver_override);
1320 	device_unlock(dev);
1321 
1322 	return len;
1323 }
1324 
1325 static ssize_t driver_override_store(struct device *dev,
1326 				     struct device_attribute *attr,
1327 				     const char *buf, size_t count)
1328 {
1329 	struct platform_device *pdev = to_platform_device(dev);
1330 	int ret;
1331 
1332 	ret = driver_set_override(dev, &pdev->driver_override, buf, count);
1333 	if (ret)
1334 		return ret;
1335 
1336 	return count;
1337 }
1338 static DEVICE_ATTR_RW(driver_override);
1339 
1340 static struct attribute *platform_dev_attrs[] = {
1341 	&dev_attr_modalias.attr,
1342 	&dev_attr_numa_node.attr,
1343 	&dev_attr_driver_override.attr,
1344 	NULL,
1345 };
1346 
1347 static umode_t platform_dev_attrs_visible(struct kobject *kobj,
1348 					  struct attribute *a, int n)
1349 {
1350 	struct device *dev = container_of(kobj, typeof(*dev), kobj);
1351 
1352 	if (a == &dev_attr_numa_node.attr && dev_to_node(dev) == NUMA_NO_NODE)
1353 		return 0;
1354 
1355 	return a->mode;
1356 }
1357 
1358 static const struct attribute_group platform_dev_group = {
1359 	.attrs = platform_dev_attrs,
1360 	.is_visible = platform_dev_attrs_visible,
1361 };
1362 __ATTRIBUTE_GROUPS(platform_dev);
1363 
1364 /**
1365  * platform_match - bind platform device to platform driver.
1366  * @dev: device.
1367  * @drv: driver.
1368  *
1369  * Platform device IDs are assumed to be encoded like this:
1370  * "<name><instance>", where <name> is a short description of the type of
1371  * device, like "pci" or "floppy", and <instance> is the enumerated
1372  * instance of the device, like '0' or '42'.  Driver IDs are simply
1373  * "<name>".  So, extract the <name> from the platform_device structure,
1374  * and compare it against the name of the driver. Return whether they match
1375  * or not.
1376  */
1377 static int platform_match(struct device *dev, const struct device_driver *drv)
1378 {
1379 	struct platform_device *pdev = to_platform_device(dev);
1380 	struct platform_driver *pdrv = to_platform_driver(drv);
1381 
1382 	/* When driver_override is set, only bind to the matching driver */
1383 	if (pdev->driver_override)
1384 		return !strcmp(pdev->driver_override, drv->name);
1385 
1386 	/* Attempt an OF style match first */
1387 	if (of_driver_match_device(dev, drv))
1388 		return 1;
1389 
1390 	/* Then try ACPI style match */
1391 	if (acpi_driver_match_device(dev, drv))
1392 		return 1;
1393 
1394 	/* Then try to match against the id table */
1395 	if (pdrv->id_table)
1396 		return platform_match_id(pdrv->id_table, pdev) != NULL;
1397 
1398 	/* fall-back to driver name match */
1399 	return (strcmp(pdev->name, drv->name) == 0);
1400 }
1401 
1402 static int platform_uevent(const struct device *dev, struct kobj_uevent_env *env)
1403 {
1404 	const struct platform_device *pdev = to_platform_device(dev);
1405 	int rc;
1406 
1407 	/* Some devices have extra OF data and an OF-style MODALIAS */
1408 	rc = of_device_uevent_modalias(dev, env);
1409 	if (rc != -ENODEV)
1410 		return rc;
1411 
1412 	rc = acpi_device_uevent_modalias(dev, env);
1413 	if (rc != -ENODEV)
1414 		return rc;
1415 
1416 	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX, pdev->name);
1417 	return 0;
1418 }
1419 
1420 static int platform_probe(struct device *_dev)
1421 {
1422 	struct platform_driver *drv = to_platform_driver(_dev->driver);
1423 	struct platform_device *dev = to_platform_device(_dev);
1424 	int ret;
1425 
1426 	/*
1427 	 * A driver registered using platform_driver_probe() cannot be bound
1428 	 * again later because the probe function usually lives in __init code
1429 	 * and so is gone. For these drivers .probe is set to
1430 	 * platform_probe_fail in __platform_driver_probe(). Don't even prepare
1431 	 * clocks and PM domains for these to match the traditional behaviour.
1432 	 */
1433 	if (unlikely(drv->probe == platform_probe_fail))
1434 		return -ENXIO;
1435 
1436 	ret = of_clk_set_defaults(_dev->of_node, false);
1437 	if (ret < 0)
1438 		return ret;
1439 
1440 	ret = dev_pm_domain_attach(_dev, PD_FLAG_ATTACH_POWER_ON |
1441 					 PD_FLAG_DETACH_POWER_OFF);
1442 	if (ret)
1443 		goto out;
1444 
1445 	if (drv->probe)
1446 		ret = drv->probe(dev);
1447 
1448 out:
1449 	if (drv->prevent_deferred_probe && ret == -EPROBE_DEFER) {
1450 		dev_warn(_dev, "probe deferral not supported\n");
1451 		ret = -ENXIO;
1452 	}
1453 
1454 	return ret;
1455 }
1456 
1457 static void platform_remove(struct device *_dev)
1458 {
1459 	struct platform_driver *drv = to_platform_driver(_dev->driver);
1460 	struct platform_device *dev = to_platform_device(_dev);
1461 
1462 	if (drv->remove)
1463 		drv->remove(dev);
1464 }
1465 
1466 static void platform_shutdown(struct device *_dev)
1467 {
1468 	struct platform_device *dev = to_platform_device(_dev);
1469 	struct platform_driver *drv;
1470 
1471 	if (!_dev->driver)
1472 		return;
1473 
1474 	drv = to_platform_driver(_dev->driver);
1475 	if (drv->shutdown)
1476 		drv->shutdown(dev);
1477 }
1478 
1479 static int platform_dma_configure(struct device *dev)
1480 {
1481 	struct device_driver *drv = READ_ONCE(dev->driver);
1482 	struct fwnode_handle *fwnode = dev_fwnode(dev);
1483 	enum dev_dma_attr attr;
1484 	int ret = 0;
1485 
1486 	if (is_of_node(fwnode)) {
1487 		ret = of_dma_configure(dev, to_of_node(fwnode), true);
1488 	} else if (is_acpi_device_node(fwnode)) {
1489 		attr = acpi_get_dma_attr(to_acpi_device_node(fwnode));
1490 		ret = acpi_dma_configure(dev, attr);
1491 	}
1492 	/* @dev->driver may not be valid when we're called from the IOMMU layer */
1493 	if (ret || !drv || to_platform_driver(drv)->driver_managed_dma)
1494 		return ret;
1495 
1496 	ret = iommu_device_use_default_domain(dev);
1497 	if (ret)
1498 		arch_teardown_dma_ops(dev);
1499 
1500 	return ret;
1501 }
1502 
1503 static void platform_dma_cleanup(struct device *dev)
1504 {
1505 	struct platform_driver *drv = to_platform_driver(dev->driver);
1506 
1507 	if (!drv->driver_managed_dma)
1508 		iommu_device_unuse_default_domain(dev);
1509 }
1510 
1511 static const struct dev_pm_ops platform_dev_pm_ops = {
1512 	SET_RUNTIME_PM_OPS(pm_generic_runtime_suspend, pm_generic_runtime_resume, NULL)
1513 	USE_PLATFORM_PM_SLEEP_OPS
1514 };
1515 
1516 const struct bus_type platform_bus_type = {
1517 	.name		= "platform",
1518 	.dev_groups	= platform_dev_groups,
1519 	.match		= platform_match,
1520 	.uevent		= platform_uevent,
1521 	.probe		= platform_probe,
1522 	.remove		= platform_remove,
1523 	.shutdown	= platform_shutdown,
1524 	.dma_configure	= platform_dma_configure,
1525 	.dma_cleanup	= platform_dma_cleanup,
1526 	.pm		= &platform_dev_pm_ops,
1527 };
1528 EXPORT_SYMBOL_GPL(platform_bus_type);
1529 
1530 static inline int __platform_match(struct device *dev, const void *drv)
1531 {
1532 	return platform_match(dev, (struct device_driver *)drv);
1533 }
1534 
1535 /**
1536  * platform_find_device_by_driver - Find a platform device with a given
1537  * driver.
1538  * @start: The device to start the search from.
1539  * @drv: The device driver to look for.
1540  */
1541 struct device *platform_find_device_by_driver(struct device *start,
1542 					      const struct device_driver *drv)
1543 {
1544 	return bus_find_device(&platform_bus_type, start, drv,
1545 			       __platform_match);
1546 }
1547 EXPORT_SYMBOL_GPL(platform_find_device_by_driver);
1548 
1549 void __weak __init early_platform_cleanup(void) { }
1550 
1551 int __init platform_bus_init(void)
1552 {
1553 	int error;
1554 
1555 	early_platform_cleanup();
1556 
1557 	error = device_register(&platform_bus);
1558 	if (error) {
1559 		put_device(&platform_bus);
1560 		return error;
1561 	}
1562 	error =  bus_register(&platform_bus_type);
1563 	if (error)
1564 		device_unregister(&platform_bus);
1565 
1566 	return error;
1567 }
1568