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torvalds
GitHub Repository: torvalds/linux
Path: blob/master/drivers/base/platform.c
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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 interupt 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(
848
const struct platform_device_info *pdevinfo)
849
{
850
int ret;
851
struct platform_device *pdev;
852
853
pdev = platform_device_alloc(pdevinfo->name, pdevinfo->id);
854
if (!pdev)
855
return ERR_PTR(-ENOMEM);
856
857
pdev->dev.parent = pdevinfo->parent;
858
pdev->dev.fwnode = pdevinfo->fwnode;
859
pdev->dev.of_node = of_node_get(to_of_node(pdev->dev.fwnode));
860
pdev->dev.of_node_reused = pdevinfo->of_node_reused;
861
862
if (pdevinfo->dma_mask) {
863
pdev->platform_dma_mask = pdevinfo->dma_mask;
864
pdev->dev.dma_mask = &pdev->platform_dma_mask;
865
pdev->dev.coherent_dma_mask = pdevinfo->dma_mask;
866
}
867
868
ret = platform_device_add_resources(pdev,
869
pdevinfo->res, pdevinfo->num_res);
870
if (ret)
871
goto err;
872
873
ret = platform_device_add_data(pdev,
874
pdevinfo->data, pdevinfo->size_data);
875
if (ret)
876
goto err;
877
878
if (pdevinfo->properties) {
879
ret = device_create_managed_software_node(&pdev->dev,
880
pdevinfo->properties, NULL);
881
if (ret)
882
goto err;
883
}
884
885
ret = platform_device_add(pdev);
886
if (ret) {
887
err:
888
ACPI_COMPANION_SET(&pdev->dev, NULL);
889
platform_device_put(pdev);
890
return ERR_PTR(ret);
891
}
892
893
return pdev;
894
}
895
EXPORT_SYMBOL_GPL(platform_device_register_full);
896
897
/**
898
* __platform_driver_register - register a driver for platform-level devices
899
* @drv: platform driver structure
900
* @owner: owning module/driver
901
*/
902
int __platform_driver_register(struct platform_driver *drv,
903
struct module *owner)
904
{
905
drv->driver.owner = owner;
906
drv->driver.bus = &platform_bus_type;
907
908
return driver_register(&drv->driver);
909
}
910
EXPORT_SYMBOL_GPL(__platform_driver_register);
911
912
/**
913
* platform_driver_unregister - unregister a driver for platform-level devices
914
* @drv: platform driver structure
915
*/
916
void platform_driver_unregister(struct platform_driver *drv)
917
{
918
driver_unregister(&drv->driver);
919
}
920
EXPORT_SYMBOL_GPL(platform_driver_unregister);
921
922
static int platform_probe_fail(struct platform_device *pdev)
923
{
924
return -ENXIO;
925
}
926
927
static int is_bound_to_driver(struct device *dev, void *driver)
928
{
929
if (dev->driver == driver)
930
return 1;
931
return 0;
932
}
933
934
/**
935
* __platform_driver_probe - register driver for non-hotpluggable device
936
* @drv: platform driver structure
937
* @probe: the driver probe routine, probably from an __init section
938
* @module: module which will be the owner of the driver
939
*
940
* Use this instead of platform_driver_register() when you know the device
941
* is not hotpluggable and has already been registered, and you want to
942
* remove its run-once probe() infrastructure from memory after the driver
943
* has bound to the device.
944
*
945
* One typical use for this would be with drivers for controllers integrated
946
* into system-on-chip processors, where the controller devices have been
947
* configured as part of board setup.
948
*
949
* Note that this is incompatible with deferred probing.
950
*
951
* Returns zero if the driver registered and bound to a device, else returns
952
* a negative error code and with the driver not registered.
953
*/
954
int __init_or_module __platform_driver_probe(struct platform_driver *drv,
955
int (*probe)(struct platform_device *), struct module *module)
956
{
957
int retval;
958
959
if (drv->driver.probe_type == PROBE_PREFER_ASYNCHRONOUS) {
960
pr_err("%s: drivers registered with %s can not be probed asynchronously\n",
961
drv->driver.name, __func__);
962
return -EINVAL;
963
}
964
965
/*
966
* We have to run our probes synchronously because we check if
967
* we find any devices to bind to and exit with error if there
968
* are any.
969
*/
970
drv->driver.probe_type = PROBE_FORCE_SYNCHRONOUS;
971
972
/*
973
* Prevent driver from requesting probe deferral to avoid further
974
* futile probe attempts.
975
*/
976
drv->prevent_deferred_probe = true;
977
978
/* make sure driver won't have bind/unbind attributes */
979
drv->driver.suppress_bind_attrs = true;
980
981
/* temporary section violation during probe() */
982
drv->probe = probe;
983
retval = __platform_driver_register(drv, module);
984
if (retval)
985
return retval;
986
987
/* Force all new probes of this driver to fail */
988
drv->probe = platform_probe_fail;
989
990
/* Walk all platform devices and see if any actually bound to this driver.
991
* If not, return an error as the device should have done so by now.
992
*/
993
if (!bus_for_each_dev(&platform_bus_type, NULL, &drv->driver, is_bound_to_driver)) {
994
retval = -ENODEV;
995
platform_driver_unregister(drv);
996
}
997
998
return retval;
999
}
1000
EXPORT_SYMBOL_GPL(__platform_driver_probe);
1001
1002
/**
1003
* __platform_create_bundle - register driver and create corresponding device
1004
* @driver: platform driver structure
1005
* @probe: the driver probe routine, probably from an __init section
1006
* @res: set of resources that needs to be allocated for the device
1007
* @n_res: number of resources
1008
* @data: platform specific data for this platform device
1009
* @size: size of platform specific data
1010
* @module: module which will be the owner of the driver
1011
*
1012
* Use this in legacy-style modules that probe hardware directly and
1013
* register a single platform device and corresponding platform driver.
1014
*
1015
* Returns &struct platform_device pointer on success, or ERR_PTR() on error.
1016
*/
1017
struct platform_device * __init_or_module __platform_create_bundle(
1018
struct platform_driver *driver,
1019
int (*probe)(struct platform_device *),
1020
struct resource *res, unsigned int n_res,
1021
const void *data, size_t size, struct module *module)
1022
{
1023
struct platform_device *pdev;
1024
int error;
1025
1026
pdev = platform_device_alloc(driver->driver.name, PLATFORM_DEVID_NONE);
1027
if (!pdev) {
1028
error = -ENOMEM;
1029
goto err_out;
1030
}
1031
1032
error = platform_device_add_resources(pdev, res, n_res);
1033
if (error)
1034
goto err_pdev_put;
1035
1036
error = platform_device_add_data(pdev, data, size);
1037
if (error)
1038
goto err_pdev_put;
1039
1040
error = platform_device_add(pdev);
1041
if (error)
1042
goto err_pdev_put;
1043
1044
error = __platform_driver_probe(driver, probe, module);
1045
if (error)
1046
goto err_pdev_del;
1047
1048
return pdev;
1049
1050
err_pdev_del:
1051
platform_device_del(pdev);
1052
err_pdev_put:
1053
platform_device_put(pdev);
1054
err_out:
1055
return ERR_PTR(error);
1056
}
1057
EXPORT_SYMBOL_GPL(__platform_create_bundle);
1058
1059
/**
1060
* __platform_register_drivers - register an array of platform drivers
1061
* @drivers: an array of drivers to register
1062
* @count: the number of drivers to register
1063
* @owner: module owning the drivers
1064
*
1065
* Registers platform drivers specified by an array. On failure to register a
1066
* driver, all previously registered drivers will be unregistered. Callers of
1067
* this API should use platform_unregister_drivers() to unregister drivers in
1068
* the reverse order.
1069
*
1070
* Returns: 0 on success or a negative error code on failure.
1071
*/
1072
int __platform_register_drivers(struct platform_driver * const *drivers,
1073
unsigned int count, struct module *owner)
1074
{
1075
unsigned int i;
1076
int err;
1077
1078
for (i = 0; i < count; i++) {
1079
pr_debug("registering platform driver %ps\n", drivers[i]);
1080
1081
err = __platform_driver_register(drivers[i], owner);
1082
if (err < 0) {
1083
pr_err("failed to register platform driver %ps: %d\n",
1084
drivers[i], err);
1085
goto error;
1086
}
1087
}
1088
1089
return 0;
1090
1091
error:
1092
while (i--) {
1093
pr_debug("unregistering platform driver %ps\n", drivers[i]);
1094
platform_driver_unregister(drivers[i]);
1095
}
1096
1097
return err;
1098
}
1099
EXPORT_SYMBOL_GPL(__platform_register_drivers);
1100
1101
/**
1102
* platform_unregister_drivers - unregister an array of platform drivers
1103
* @drivers: an array of drivers to unregister
1104
* @count: the number of drivers to unregister
1105
*
1106
* Unregisters platform drivers specified by an array. This is typically used
1107
* to complement an earlier call to platform_register_drivers(). Drivers are
1108
* unregistered in the reverse order in which they were registered.
1109
*/
1110
void platform_unregister_drivers(struct platform_driver * const *drivers,
1111
unsigned int count)
1112
{
1113
while (count--) {
1114
pr_debug("unregistering platform driver %ps\n", drivers[count]);
1115
platform_driver_unregister(drivers[count]);
1116
}
1117
}
1118
EXPORT_SYMBOL_GPL(platform_unregister_drivers);
1119
1120
static const struct platform_device_id *platform_match_id(
1121
const struct platform_device_id *id,
1122
struct platform_device *pdev)
1123
{
1124
while (id->name[0]) {
1125
if (strcmp(pdev->name, id->name) == 0) {
1126
pdev->id_entry = id;
1127
return id;
1128
}
1129
id++;
1130
}
1131
return NULL;
1132
}
1133
1134
#ifdef CONFIG_PM_SLEEP
1135
1136
static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
1137
{
1138
struct platform_driver *pdrv = to_platform_driver(dev->driver);
1139
struct platform_device *pdev = to_platform_device(dev);
1140
int ret = 0;
1141
1142
if (dev->driver && pdrv->suspend)
1143
ret = pdrv->suspend(pdev, mesg);
1144
1145
return ret;
1146
}
1147
1148
static int platform_legacy_resume(struct device *dev)
1149
{
1150
struct platform_driver *pdrv = to_platform_driver(dev->driver);
1151
struct platform_device *pdev = to_platform_device(dev);
1152
int ret = 0;
1153
1154
if (dev->driver && pdrv->resume)
1155
ret = pdrv->resume(pdev);
1156
1157
return ret;
1158
}
1159
1160
#endif /* CONFIG_PM_SLEEP */
1161
1162
#ifdef CONFIG_SUSPEND
1163
1164
int platform_pm_suspend(struct device *dev)
1165
{
1166
const struct device_driver *drv = dev->driver;
1167
int ret = 0;
1168
1169
if (!drv)
1170
return 0;
1171
1172
if (drv->pm) {
1173
if (drv->pm->suspend)
1174
ret = drv->pm->suspend(dev);
1175
} else {
1176
ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
1177
}
1178
1179
return ret;
1180
}
1181
1182
int platform_pm_resume(struct device *dev)
1183
{
1184
const struct device_driver *drv = dev->driver;
1185
int ret = 0;
1186
1187
if (!drv)
1188
return 0;
1189
1190
if (drv->pm) {
1191
if (drv->pm->resume)
1192
ret = drv->pm->resume(dev);
1193
} else {
1194
ret = platform_legacy_resume(dev);
1195
}
1196
1197
return ret;
1198
}
1199
1200
#endif /* CONFIG_SUSPEND */
1201
1202
#ifdef CONFIG_HIBERNATE_CALLBACKS
1203
1204
int platform_pm_freeze(struct device *dev)
1205
{
1206
const 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->freeze)
1214
ret = drv->pm->freeze(dev);
1215
} else {
1216
ret = platform_legacy_suspend(dev, PMSG_FREEZE);
1217
}
1218
1219
return ret;
1220
}
1221
1222
int platform_pm_thaw(struct device *dev)
1223
{
1224
const struct device_driver *drv = dev->driver;
1225
int ret = 0;
1226
1227
if (!drv)
1228
return 0;
1229
1230
if (drv->pm) {
1231
if (drv->pm->thaw)
1232
ret = drv->pm->thaw(dev);
1233
} else {
1234
ret = platform_legacy_resume(dev);
1235
}
1236
1237
return ret;
1238
}
1239
1240
int platform_pm_poweroff(struct device *dev)
1241
{
1242
const struct device_driver *drv = dev->driver;
1243
int ret = 0;
1244
1245
if (!drv)
1246
return 0;
1247
1248
if (drv->pm) {
1249
if (drv->pm->poweroff)
1250
ret = drv->pm->poweroff(dev);
1251
} else {
1252
ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
1253
}
1254
1255
return ret;
1256
}
1257
1258
int platform_pm_restore(struct device *dev)
1259
{
1260
const struct device_driver *drv = dev->driver;
1261
int ret = 0;
1262
1263
if (!drv)
1264
return 0;
1265
1266
if (drv->pm) {
1267
if (drv->pm->restore)
1268
ret = drv->pm->restore(dev);
1269
} else {
1270
ret = platform_legacy_resume(dev);
1271
}
1272
1273
return ret;
1274
}
1275
1276
#endif /* CONFIG_HIBERNATE_CALLBACKS */
1277
1278
/* modalias support enables more hands-off userspace setup:
1279
* (a) environment variable lets new-style hotplug events work once system is
1280
* fully running: "modprobe $MODALIAS"
1281
* (b) sysfs attribute lets new-style coldplug recover from hotplug events
1282
* mishandled before system is fully running: "modprobe $(cat modalias)"
1283
*/
1284
static ssize_t modalias_show(struct device *dev,
1285
struct device_attribute *attr, char *buf)
1286
{
1287
struct platform_device *pdev = to_platform_device(dev);
1288
int len;
1289
1290
len = of_device_modalias(dev, buf, PAGE_SIZE);
1291
if (len != -ENODEV)
1292
return len;
1293
1294
len = acpi_device_modalias(dev, buf, PAGE_SIZE - 1);
1295
if (len != -ENODEV)
1296
return len;
1297
1298
return sysfs_emit(buf, "platform:%s\n", pdev->name);
1299
}
1300
static DEVICE_ATTR_RO(modalias);
1301
1302
static ssize_t numa_node_show(struct device *dev,
1303
struct device_attribute *attr, char *buf)
1304
{
1305
return sysfs_emit(buf, "%d\n", dev_to_node(dev));
1306
}
1307
static DEVICE_ATTR_RO(numa_node);
1308
1309
static ssize_t driver_override_show(struct device *dev,
1310
struct device_attribute *attr, char *buf)
1311
{
1312
struct platform_device *pdev = to_platform_device(dev);
1313
ssize_t len;
1314
1315
device_lock(dev);
1316
len = sysfs_emit(buf, "%s\n", pdev->driver_override);
1317
device_unlock(dev);
1318
1319
return len;
1320
}
1321
1322
static ssize_t driver_override_store(struct device *dev,
1323
struct device_attribute *attr,
1324
const char *buf, size_t count)
1325
{
1326
struct platform_device *pdev = to_platform_device(dev);
1327
int ret;
1328
1329
ret = driver_set_override(dev, &pdev->driver_override, buf, count);
1330
if (ret)
1331
return ret;
1332
1333
return count;
1334
}
1335
static DEVICE_ATTR_RW(driver_override);
1336
1337
static struct attribute *platform_dev_attrs[] = {
1338
&dev_attr_modalias.attr,
1339
&dev_attr_numa_node.attr,
1340
&dev_attr_driver_override.attr,
1341
NULL,
1342
};
1343
1344
static umode_t platform_dev_attrs_visible(struct kobject *kobj, struct attribute *a,
1345
int n)
1346
{
1347
struct device *dev = container_of(kobj, typeof(*dev), kobj);
1348
1349
if (a == &dev_attr_numa_node.attr &&
1350
dev_to_node(dev) == NUMA_NO_NODE)
1351
return 0;
1352
1353
return a->mode;
1354
}
1355
1356
static const struct attribute_group platform_dev_group = {
1357
.attrs = platform_dev_attrs,
1358
.is_visible = platform_dev_attrs_visible,
1359
};
1360
__ATTRIBUTE_GROUPS(platform_dev);
1361
1362
1363
/**
1364
* platform_match - bind platform device to platform driver.
1365
* @dev: device.
1366
* @drv: driver.
1367
*
1368
* Platform device IDs are assumed to be encoded like this:
1369
* "<name><instance>", where <name> is a short description of the type of
1370
* device, like "pci" or "floppy", and <instance> is the enumerated
1371
* instance of the device, like '0' or '42'. Driver IDs are simply
1372
* "<name>". So, extract the <name> from the platform_device structure,
1373
* and compare it against the name of the driver. Return whether they match
1374
* or not.
1375
*/
1376
static int platform_match(struct device *dev, const struct device_driver *drv)
1377
{
1378
struct platform_device *pdev = to_platform_device(dev);
1379
struct platform_driver *pdrv = to_platform_driver(drv);
1380
1381
/* When driver_override is set, only bind to the matching driver */
1382
if (pdev->driver_override)
1383
return !strcmp(pdev->driver_override, drv->name);
1384
1385
/* Attempt an OF style match first */
1386
if (of_driver_match_device(dev, drv))
1387
return 1;
1388
1389
/* Then try ACPI style match */
1390
if (acpi_driver_match_device(dev, drv))
1391
return 1;
1392
1393
/* Then try to match against the id table */
1394
if (pdrv->id_table)
1395
return platform_match_id(pdrv->id_table, pdev) != NULL;
1396
1397
/* fall-back to driver name match */
1398
return (strcmp(pdev->name, drv->name) == 0);
1399
}
1400
1401
static int platform_uevent(const struct device *dev, struct kobj_uevent_env *env)
1402
{
1403
const struct platform_device *pdev = to_platform_device(dev);
1404
int rc;
1405
1406
/* Some devices have extra OF data and an OF-style MODALIAS */
1407
rc = of_device_uevent_modalias(dev, env);
1408
if (rc != -ENODEV)
1409
return rc;
1410
1411
rc = acpi_device_uevent_modalias(dev, env);
1412
if (rc != -ENODEV)
1413
return rc;
1414
1415
add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
1416
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
1569