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