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