aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/base/platform.c
blob: 99a5272d7c2fde1d3b148fc0fd2150fc9ffb8121 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
/*
 * platform.c - platform 'pseudo' bus for legacy devices
 *
 * Copyright (c) 2002-3 Patrick Mochel
 * Copyright (c) 2002-3 Open Source Development Labs
 *
 * This file is released under the GPLv2
 *
 * Please see Documentation/driver-model/platform.txt for more
 * information.
 */

#include <linux/string.h>
#include <linux/platform_device.h>
#include <linux/of_device.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <linux/bootmem.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>

#include "base.h"

#define to_platform_driver(drv)	(container_of((drv), struct platform_driver, \
				 driver))

struct device platform_bus = {
	.init_name	= "platform",
};
EXPORT_SYMBOL_GPL(platform_bus);

/**
 * arch_setup_pdev_archdata - Allow manipulation of archdata before its used
 * @pdev: platform device
 *
 * This is called before platform_device_add() such that any pdev_archdata may
 * be setup before the platform_notifier is called.  So if a user needs to
 * manipulate any relevant information in the pdev_archdata they can do:
 *
 * 	platform_devic_alloc()
 * 	... manipulate ...
 * 	platform_device_add()
 *
 * And if they don't care they can just call platform_device_register() and
 * everything will just work out.
 */
void __weak arch_setup_pdev_archdata(struct platform_device *pdev)
{
}

/**
 * platform_get_resource - get a resource for a device
 * @dev: platform device
 * @type: resource type
 * @num: resource index
 */
struct resource *platform_get_resource(struct platform_device *dev,
				       unsigned int type, unsigned int num)
{
	int i;

	for (i = 0; i < dev->num_resources; i++) {
		struct resource *r = &dev->resource[i];

		if (type == resource_type(r) && num-- == 0)
			return r;
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(platform_get_resource);

/**
 * platform_get_irq - get an IRQ for a device
 * @dev: platform device
 * @num: IRQ number index
 */
int platform_get_irq(struct platform_device *dev, unsigned int num)
{
	struct resource *r = platform_get_resource(dev, IORESOURCE_IRQ, num);

	return r ? r->start : -ENXIO;
}
EXPORT_SYMBOL_GPL(platform_get_irq);

/**
 * platform_get_resource_byname - get a resource for a device by name
 * @dev: platform device
 * @type: resource type
 * @name: resource name
 */
struct resource *platform_get_resource_byname(struct platform_device *dev,
					      unsigned int type,
					      const char *name)
{
	int i;

	for (i = 0; i < dev->num_resources; i++) {
		struct resource *r = &dev->resource[i];

		if (type == resource_type(r) && !strcmp(r->name, name))
			return r;
	}
	return NULL;
}
EXPORT_SYMBOL_GPL(platform_get_resource_byname);

/**
 * platform_get_irq - get an IRQ for a device
 * @dev: platform device
 * @name: IRQ name
 */
int platform_get_irq_byname(struct platform_device *dev, const char *name)
{
	struct resource *r = platform_get_resource_byname(dev, IORESOURCE_IRQ,
							  name);

	return r ? r->start : -ENXIO;
}
EXPORT_SYMBOL_GPL(platform_get_irq_byname);

/**
 * platform_add_devices - add a numbers of platform devices
 * @devs: array of platform devices to add
 * @num: number of platform devices in array
 */
int platform_add_devices(struct platform_device **devs, int num)
{
	int i, ret = 0;

	for (i = 0; i < num; i++) {
		ret = platform_device_register(devs[i]);
		if (ret) {
			while (--i >= 0)
				platform_device_unregister(devs[i]);
			break;
		}
	}

	return ret;
}
EXPORT_SYMBOL_GPL(platform_add_devices);

struct platform_object {
	struct platform_device pdev;
	char name[1];
};

/**
 * platform_device_put - destroy a platform device
 * @pdev: platform device to free
 *
 * Free all memory associated with a platform device.  This function must
 * _only_ be externally called in error cases.  All other usage is a bug.
 */
void platform_device_put(struct platform_device *pdev)
{
	if (pdev)
		put_device(&pdev->dev);
}
EXPORT_SYMBOL_GPL(platform_device_put);

static void platform_device_release(struct device *dev)
{
	struct platform_object *pa = container_of(dev, struct platform_object,
						  pdev.dev);

	of_device_node_put(&pa->pdev.dev);
	kfree(pa->pdev.dev.platform_data);
	kfree(pa->pdev.mfd_cell);
	kfree(pa->pdev.resource);
	kfree(pa);
}

/**
 * platform_device_alloc - create a platform device
 * @name: base name of the device we're adding
 * @id: instance id
 *
 * Create a platform device object which can have other objects attached
 * to it, and which will have attached objects freed when it is released.
 */
struct platform_device *platform_device_alloc(const char *name, int id)
{
	struct platform_object *pa;

	pa = kzalloc(sizeof(struct platform_object) + strlen(name), GFP_KERNEL);
	if (pa) {
		strcpy(pa->name, name);
		pa->pdev.name = pa->name;
		pa->pdev.id = id;
		device_initialize(&pa->pdev.dev);
		pa->pdev.dev.release = platform_device_release;
		arch_setup_pdev_archdata(&pa->pdev);
	}

	return pa ? &pa->pdev : NULL;
}
EXPORT_SYMBOL_GPL(platform_device_alloc);

/**
 * platform_device_add_resources - add resources to a platform device
 * @pdev: platform device allocated by platform_device_alloc to add resources to
 * @res: set of resources that needs to be allocated for the device
 * @num: number of resources
 *
 * Add a copy of the resources to the platform device.  The memory
 * associated with the resources will be freed when the platform device is
 * released.
 */
int platform_device_add_resources(struct platform_device *pdev,
				  const struct resource *res, unsigned int num)
{
	struct resource *r = NULL;

	if (res) {
		r = kmemdup(res, sizeof(struct resource) * num, GFP_KERNEL);
		if (!r)
			return -ENOMEM;
	}

	kfree(pdev->resource);
	pdev->resource = r;
	pdev->num_resources = num;
	return 0;
}
EXPORT_SYMBOL_GPL(platform_device_add_resources);

/**
 * platform_device_add_data - add platform-specific data to a platform device
 * @pdev: platform device allocated by platform_device_alloc to add resources to
 * @data: platform specific data for this platform device
 * @size: size of platform specific data
 *
 * Add a copy of platform specific data to the platform device's
 * platform_data pointer.  The memory associated with the platform data
 * will be freed when the platform device is released.
 */
int platform_device_add_data(struct platform_device *pdev, const void *data,
			     size_t size)
{
	void *d = NULL;

	if (data) {
		d = kmemdup(data, size, GFP_KERNEL);
		if (!d)
			return -ENOMEM;
	}

	kfree(pdev->dev.platform_data);
	pdev->dev.platform_data = d;
	return 0;
}
EXPORT_SYMBOL_GPL(platform_device_add_data);

/**
 * platform_device_add - add a platform device to device hierarchy
 * @pdev: platform device we're adding
 *
 * This is part 2 of platform_device_register(), though may be called
 * separately _iff_ pdev was allocated by platform_device_alloc().
 */
int platform_device_add(struct platform_device *pdev)
{
	int i, ret = 0;

	if (!pdev)
		return -EINVAL;

	if (!pdev->dev.parent)
		pdev->dev.parent = &platform_bus;

	pdev->dev.bus = &platform_bus_type;

	if (pdev->id != -1)
		dev_set_name(&pdev->dev, "%s.%d", pdev->name,  pdev->id);
	else
		dev_set_name(&pdev->dev, "%s", pdev->name);

	for (i = 0; i < pdev->num_resources; i++) {
		struct resource *p, *r = &pdev->resource[i];

		if (r->name == NULL)
			r->name = dev_name(&pdev->dev);

		p = r->parent;
		if (!p) {
			if (resource_type(r) == IORESOURCE_MEM)
				p = &iomem_resource;
			else if (resource_type(r) == IORESOURCE_IO)
				p = &ioport_resource;
		}

		if (p && insert_resource(p, r)) {
			printk(KERN_ERR
			       "%s: failed to claim resource %d\n",
			       dev_name(&pdev->dev), i);
			ret = -EBUSY;
			goto failed;
		}
	}

	pr_debug("Registering platform device '%s'. Parent at %s\n",
		 dev_name(&pdev->dev), dev_name(pdev->dev.parent));

	ret = device_add(&pdev->dev);
	if (ret == 0)
		return ret;

 failed:
	while (--i >= 0) {
		struct resource *r = &pdev->resource[i];
		unsigned long type = resource_type(r);

		if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
			release_resource(r);
	}

	return ret;
}
EXPORT_SYMBOL_GPL(platform_device_add);

/**
 * platform_device_del - remove a platform-level device
 * @pdev: platform device we're removing
 *
 * Note that this function will also release all memory- and port-based
 * resources owned by the device (@dev->resource).  This function must
 * _only_ be externally called in error cases.  All other usage is a bug.
 */
void platform_device_del(struct platform_device *pdev)
{
	int i;

	if (pdev) {
		device_del(&pdev->dev);

		for (i = 0; i < pdev->num_resources; i++) {
			struct resource *r = &pdev->resource[i];
			unsigned long type = resource_type(r);

			if (type == IORESOURCE_MEM || type == IORESOURCE_IO)
				release_resource(r);
		}
	}
}
EXPORT_SYMBOL_GPL(platform_device_del);

/**
 * platform_device_register - add a platform-level device
 * @pdev: platform device we're adding
 */
int platform_device_register(struct platform_device *pdev)
{
	device_initialize(&pdev->dev);
	arch_setup_pdev_archdata(pdev);
	return platform_device_add(pdev);
}
EXPORT_SYMBOL_GPL(platform_device_register);

/**
 * platform_device_unregister - unregister a platform-level device
 * @pdev: platform device we're unregistering
 *
 * Unregistration is done in 2 steps. First we release all resources
 * and remove it from the subsystem, then we drop reference count by
 * calling platform_device_put().
 */
void platform_device_unregister(struct platform_device *pdev)
{
	platform_device_del(pdev);
	platform_device_put(pdev);
}
EXPORT_SYMBOL_GPL(platform_device_unregister);

/**
 * platform_device_register_resndata - add a platform-level device with
 * resources and platform-specific data
 *
 * @parent: parent device for the device we're adding
 * @name: base name of the device we're adding
 * @id: instance id
 * @res: set of resources that needs to be allocated for the device
 * @num: number of resources
 * @data: platform specific data for this platform device
 * @size: size of platform specific data
 *
 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
 */
struct platform_device *platform_device_register_resndata(
		struct device *parent,
		const char *name, int id,
		const struct resource *res, unsigned int num,
		const void *data, size_t size)
{
	int ret = -ENOMEM;
	struct platform_device *pdev;

	pdev = platform_device_alloc(name, id);
	if (!pdev)
		goto err;

	pdev->dev.parent = parent;

	ret = platform_device_add_resources(pdev, res, num);
	if (ret)
		goto err;

	ret = platform_device_add_data(pdev, data, size);
	if (ret)
		goto err;

	ret = platform_device_add(pdev);
	if (ret) {
err:
		platform_device_put(pdev);
		return ERR_PTR(ret);
	}

	return pdev;
}
EXPORT_SYMBOL_GPL(platform_device_register_resndata);

static int platform_drv_probe(struct device *_dev)
{
	struct platform_driver *drv = to_platform_driver(_dev->driver);
	struct platform_device *dev = to_platform_device(_dev);

	return drv->probe(dev);
}

static int platform_drv_probe_fail(struct device *_dev)
{
	return -ENXIO;
}

static int platform_drv_remove(struct device *_dev)
{
	struct platform_driver *drv = to_platform_driver(_dev->driver);
	struct platform_device *dev = to_platform_device(_dev);

	return drv->remove(dev);
}

static void platform_drv_shutdown(struct device *_dev)
{
	struct platform_driver *drv = to_platform_driver(_dev->driver);
	struct platform_device *dev = to_platform_device(_dev);

	drv->shutdown(dev);
}

/**
 * platform_driver_register - register a driver for platform-level devices
 * @drv: platform driver structure
 */
int platform_driver_register(struct platform_driver *drv)
{
	drv->driver.bus = &platform_bus_type;
	if (drv->probe)
		drv->driver.probe = platform_drv_probe;
	if (drv->remove)
		drv->driver.remove = platform_drv_remove;
	if (drv->shutdown)
		drv->driver.shutdown = platform_drv_shutdown;

	return driver_register(&drv->driver);
}
EXPORT_SYMBOL_GPL(platform_driver_register);

/**
 * platform_driver_unregister - unregister a driver for platform-level devices
 * @drv: platform driver structure
 */
void platform_driver_unregister(struct platform_driver *drv)
{
	driver_unregister(&drv->driver);
}
EXPORT_SYMBOL_GPL(platform_driver_unregister);

/**
 * platform_driver_probe - register driver for non-hotpluggable device
 * @drv: platform driver structure
 * @probe: the driver probe routine, probably from an __init section
 *
 * Use this instead of platform_driver_register() when you know the device
 * is not hotpluggable and has already been registered, and you want to
 * remove its run-once probe() infrastructure from memory after the driver
 * has bound to the device.
 *
 * One typical use for this would be with drivers for controllers integrated
 * into system-on-chip processors, where the controller devices have been
 * configured as part of board setup.
 *
 * Returns zero if the driver registered and bound to a device, else returns
 * a negative error code and with the driver not registered.
 */
int __init_or_module platform_driver_probe(struct platform_driver *drv,
		int (*probe)(struct platform_device *))
{
	int retval, code;

	/* make sure driver won't have bind/unbind attributes */
	drv->driver.suppress_bind_attrs = true;

	/* temporary section violation during probe() */
	drv->probe = probe;
	retval = code = platform_driver_register(drv);

	/*
	 * Fixup that section violation, being paranoid about code scanning
	 * the list of drivers in order to probe new devices.  Check to see
	 * if the probe was successful, and make sure any forced probes of
	 * new devices fail.
	 */
	spin_lock(&drv->driver.bus->p->klist_drivers.k_lock);
	drv->probe = NULL;
	if (code == 0 && list_empty(&drv->driver.p->klist_devices.k_list))
		retval = -ENODEV;
	drv->driver.probe = platform_drv_probe_fail;
	spin_unlock(&drv->driver.bus->p->klist_drivers.k_lock);

	if (code != retval)
		platform_driver_unregister(drv);
	return retval;
}
EXPORT_SYMBOL_GPL(platform_driver_probe);

/**
 * platform_create_bundle - register driver and create corresponding device
 * @driver: platform driver structure
 * @probe: the driver probe routine, probably from an __init section
 * @res: set of resources that needs to be allocated for the device
 * @n_res: number of resources
 * @data: platform specific data for this platform device
 * @size: size of platform specific data
 *
 * Use this in legacy-style modules that probe hardware directly and
 * register a single platform device and corresponding platform driver.
 *
 * Returns &struct platform_device pointer on success, or ERR_PTR() on error.
 */
struct platform_device * __init_or_module 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 platform_device *pdev;
	int error;

	pdev = platform_device_alloc(driver->driver.name, -1);
	if (!pdev) {
		error = -ENOMEM;
		goto err_out;
	}

	error = platform_device_add_resources(pdev, res, n_res);
	if (error)
		goto err_pdev_put;

	error = platform_device_add_data(pdev, data, size);
	if (error)
		goto err_pdev_put;

	error = platform_device_add(pdev);
	if (error)
		goto err_pdev_put;

	error = platform_driver_probe(driver, probe);
	if (error)
		goto err_pdev_del;

	return pdev;

err_pdev_del:
	platform_device_del(pdev);
err_pdev_put:
	platform_device_put(pdev);
err_out:
	return ERR_PTR(error);
}
EXPORT_SYMBOL_GPL(platform_create_bundle);

/* modalias support enables more hands-off userspace setup:
 * (a) environment variable lets new-style hotplug events work once system is
 *     fully running:  "modprobe $MODALIAS"
 * (b) sysfs attribute lets new-style coldplug recover from hotplug events
 *     mishandled before system is fully running:  "modprobe $(cat modalias)"
 */
static ssize_t modalias_show(struct device *dev, struct device_attribute *a,
			     char *buf)
{
	struct platform_device	*pdev = to_platform_device(dev);
	int len = snprintf(buf, PAGE_SIZE, "platform:%s\n", pdev->name);

	return (len >= PAGE_SIZE) ? (PAGE_SIZE - 1) : len;
}

static struct device_attribute platform_dev_attrs[] = {
	__ATTR_RO(modalias),
	__ATTR_NULL,
};

static int platform_uevent(struct device *dev, struct kobj_uevent_env *env)
{
	struct platform_device	*pdev = to_platform_device(dev);
	int rc;

	/* Some devices have extra OF data and an OF-style MODALIAS */
	rc = of_device_uevent(dev,env);
	if (rc != -ENODEV)
		return rc;

	add_uevent_var(env, "MODALIAS=%s%s", PLATFORM_MODULE_PREFIX,
		(pdev->id_entry) ? pdev->id_entry->name : pdev->name);
	return 0;
}

static const struct platform_device_id *platform_match_id(
			const struct platform_device_id *id,
			struct platform_device *pdev)
{
	while (id->name[0]) {
		if (strcmp(pdev->name, id->name) == 0) {
			pdev->id_entry = id;
			return id;
		}
		id++;
	}
	return NULL;
}

/**
 * platform_match - bind platform device to platform driver.
 * @dev: device.
 * @drv: driver.
 *
 * Platform device IDs are assumed to be encoded like this:
 * "<name><instance>", where <name> is a short description of the type of
 * device, like "pci" or "floppy", and <instance> is the enumerated
 * instance of the device, like '0' or '42'.  Driver IDs are simply
 * "<name>".  So, extract the <name> from the platform_device structure,
 * and compare it against the name of the driver. Return whether they match
 * or not.
 */
static int platform_match(struct device *dev, struct device_driver *drv)
{
	struct platform_device *pdev = to_platform_device(dev);
	struct platform_driver *pdrv = to_platform_driver(drv);

	/* Attempt an OF style match first */
	if (of_driver_match_device(dev, drv))
		return 1;

	/* Then try to match against the id table */
	if (pdrv->id_table)
		return platform_match_id(pdrv->id_table, pdev) != NULL;

	/* fall-back to driver name match */
	return (strcmp(pdev->name, drv->name) == 0);
}

#ifdef CONFIG_PM_SLEEP

static int platform_legacy_suspend(struct device *dev, pm_message_t mesg)
{
	struct platform_driver *pdrv = to_platform_driver(dev->driver);
	struct platform_device *pdev = to_platform_device(dev);
	int ret = 0;

	if (dev->driver && pdrv->suspend)
		ret = pdrv->suspend(pdev, mesg);

	return ret;
}

static int platform_legacy_resume(struct device *dev)
{
	struct platform_driver *pdrv = to_platform_driver(dev->driver);
	struct platform_device *pdev = to_platform_device(dev);
	int ret = 0;

	if (dev->driver && pdrv->resume)
		ret = pdrv->resume(pdev);

	return ret;
}

int platform_pm_prepare(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (drv && drv->pm && drv->pm->prepare)
		ret = drv->pm->prepare(dev);

	return ret;
}

void platform_pm_complete(struct device *dev)
{
	struct device_driver *drv = dev->driver;

	if (drv && drv->pm && drv->pm->complete)
		drv->pm->complete(dev);
}

#endif /* CONFIG_PM_SLEEP */

#ifdef CONFIG_SUSPEND

int platform_pm_suspend(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->suspend)
			ret = drv->pm->suspend(dev);
	} else {
		ret = platform_legacy_suspend(dev, PMSG_SUSPEND);
	}

	return ret;
}

int platform_pm_suspend_noirq(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->suspend_noirq)
			ret = drv->pm->suspend_noirq(dev);
	}

	return ret;
}

int platform_pm_resume(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->resume)
			ret = drv->pm->resume(dev);
	} else {
		ret = platform_legacy_resume(dev);
	}

	return ret;
}

int platform_pm_resume_noirq(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->resume_noirq)
			ret = drv->pm->resume_noirq(dev);
	}

	return ret;
}

#endif /* CONFIG_SUSPEND */

#ifdef CONFIG_HIBERNATE_CALLBACKS

int platform_pm_freeze(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->freeze)
			ret = drv->pm->freeze(dev);
	} else {
		ret = platform_legacy_suspend(dev, PMSG_FREEZE);
	}

	return ret;
}

int platform_pm_freeze_noirq(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->freeze_noirq)
			ret = drv->pm->freeze_noirq(dev);
	}

	return ret;
}

int platform_pm_thaw(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->thaw)
			ret = drv->pm->thaw(dev);
	} else {
		ret = platform_legacy_resume(dev);
	}

	return ret;
}

int platform_pm_thaw_noirq(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->thaw_noirq)
			ret = drv->pm->thaw_noirq(dev);
	}

	return ret;
}

int platform_pm_poweroff(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->poweroff)
			ret = drv->pm->poweroff(dev);
	} else {
		ret = platform_legacy_suspend(dev, PMSG_HIBERNATE);
	}

	return ret;
}

int platform_pm_poweroff_noirq(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->poweroff_noirq)
			ret = drv->pm->poweroff_noirq(dev);
	}

	return ret;
}

int platform_pm_restore(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->restore)
			ret = drv->pm->restore(dev);
	} else {
		ret = platform_legacy_resume(dev);
	}

	return ret;
}

int platform_pm_restore_noirq(struct device *dev)
{
	struct device_driver *drv = dev->driver;
	int ret = 0;

	if (!drv)
		return 0;

	if (drv->pm) {
		if (drv->pm->restore_noirq)
			ret = drv->pm->restore_noirq(dev);
	}

	return ret;
}

#endif /* CONFIG_HIBERNATE_CALLBACKS */

static const struct dev_pm_ops platform_dev_pm_ops = {
	.runtime_suspend = pm_generic_runtime_suspend,
	.runtime_resume = pm_generic_runtime_resume,
	.runtime_idle = pm_generic_runtime_idle,
	USE_PLATFORM_PM_SLEEP_OPS
};

struct bus_type platform_bus_type = {
	.name		= "platform",
	.dev_attrs	= platform_dev_attrs,
	.match		= platform_match,
	.uevent		= platform_uevent,
	.pm		= &platform_dev_pm_ops,
};
EXPORT_SYMBOL_GPL(platform_bus_type);

int __init platform_bus_init(void)
{
	int error;

	early_platform_cleanup();

	error = device_register(&platform_bus);
	if (error)
		return error;
	error =  bus_register(&platform_bus_type);
	if (error)
		device_unregister(&platform_bus);
	return error;
}

#ifndef ARCH_HAS_DMA_GET_REQUIRED_MASK
u64 dma_get_required_mask(struct device *dev)
{
	u32 low_totalram = ((max_pfn - 1) << PAGE_SHIFT);
	u32 high_totalram = ((max_pfn - 1) >> (32 - PAGE_SHIFT));
	u64 mask;

	if (!high_totalram) {
		/* convert to mask just covering totalram */
		low_totalram = (1 << (fls(low_totalram) - 1));
		low_totalram += low_totalram - 1;
		mask = low_totalram;
	} else {
		high_totalram = (1 << (fls(high_totalram) - 1));
		high_totalram += high_totalram - 1;
		mask = (((u64)high_totalram) << 32) + 0xffffffff;
	}
	return mask;
}
EXPORT_SYMBOL_GPL(dma_get_required_mask);
#endif

static __initdata LIST_HEAD(early_platform_driver_list);
static __initdata LIST_HEAD(early_platform_device_list);

/**
 * early_platform_driver_register - register early platform driver
 * @epdrv: early_platform driver structure
 * @buf: string passed from early_param()
 *
 * Helper function for early_platform_init() / early_platform_init_buffer()
 */
int __init early_platform_driver_register(struct early_platform_driver *epdrv,
					  char *buf)
{
	char *tmp;
	int n;

	/* Simply add the driver to the end of the global list.
	 * Drivers will by default be put on the list in compiled-in order.
	 */
	if (!epdrv->list.next) {
		INIT_LIST_HEAD(&epdrv->list);
		list_add_tail(&epdrv->list, &early_platform_driver_list);
	}

	/* If the user has specified device then make sure the driver
	 * gets prioritized. The driver of the last device specified on
	 * command line will be put first on the list.
	 */
	n = strlen(epdrv->pdrv->driver.name);
	if (buf && !strncmp(buf, epdrv->pdrv->driver.name, n)) {
		list_move(&epdrv->list, &early_platform_driver_list);

		/* Allow passing parameters after device name */
		if (buf[n] == '\0' || buf[n] == ',')
			epdrv->requested_id = -1;
		else {
			epdrv->requested_id = simple_strtoul(&buf[n + 1],
							     &tmp, 10);

			if (buf[n] != '.' || (tmp == &buf[n + 1])) {
				epdrv->requested_id = EARLY_PLATFORM_ID_ERROR;
				n = 0;
			} else
				n += strcspn(&buf[n + 1], ",") + 1;
		}

		if (buf[n] == ',')
			n++;

		if (epdrv->bufsize) {
			memcpy(epdrv->buffer, &buf[n],
			       min_t(int, epdrv->bufsize, strlen(&buf[n]) + 1));
			epdrv->buffer[epdrv->bufsize - 1] = '\0';
		}
	}

	return 0;
}

/**
 * early_platform_add_devices - adds a number of early platform devices
 * @devs: array of early platform devices to add
 * @num: number of early platform devices in array
 *
 * Used by early architecture code to register early platform devices and
 * their platform data.
 */
void __init early_platform_add_devices(struct platform_device **devs, int num)
{
	struct device *dev;
	int i;

	/* simply add the devices to list */
	for (i = 0; i < num; i++) {
		dev = &devs[i]->dev;

		if (!dev->devres_head.next) {
			INIT_LIST_HEAD(&dev->devres_head);
			list_add_tail(&dev->devres_head,
				      &early_platform_device_list);
		}
	}
}

/**
 * early_platform_driver_register_all - register early platform drivers
 * @class_str: string to identify early platform driver class
 *
 * Used by architecture code to register all early platform drivers
 * for a certain class. If omitted then only early platform drivers
 * with matching kernel command line class parameters will be registered.
 */
void __init early_platform_driver_register_all(char *class_str)
{
	/* The "class_str" parameter may or may not be present on the kernel
	 * command line. If it is present then there may be more than one
	 * matching parameter.
	 *
	 * Since we register our early platform drivers using early_param()
	 * we need to make sure that they also get registered in the case
	 * when the parameter is missing from the kernel command line.
	 *
	 * We use parse_early_options() to make sure the early_param() gets
	 * called at least once. The early_param() may be called more than
	 * once since the name of the preferred device may be specified on
	 * the kernel command line. early_platform_driver_register() handles
	 * this case for us.
	 */
	parse_early_options(class_str);
}

/**
 * early_platform_match - find early platform device matching driver
 * @epdrv: early platform driver structure
 * @id: id to match against
 */
static  __init struct platform_device *
early_platform_match(struct early_platform_driver *epdrv, int id)
{
	struct platform_device *pd;

	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
			if (pd->id == id)
				return pd;

	return NULL;
}

/**
 * early_platform_left - check if early platform driver has matching devices
 * @epdrv: early platform driver structure
 * @id: return true if id or above exists
 */
static  __init int early_platform_left(struct early_platform_driver *epdrv,
				       int id)
{
	struct platform_device *pd;

	list_for_each_entry(pd, &early_platform_device_list, dev.devres_head)
		if (platform_match(&pd->dev, &epdrv->pdrv->driver))
			if (pd->id >= id)
				return 1;

	return 0;
}

/**
 * early_platform_driver_probe_id - probe drivers matching class_str and id
 * @class_str: string to identify early platform driver class
 * @id: id to match against
 * @nr_probe: number of platform devices to successfully probe before exiting
 */
static int __init early_platform_driver_probe_id(char *class_str,
						 int id,
						 int nr_probe)
{
	struct early_platform_driver *epdrv;
	struct platform_device *match;
	int match_id;
	int n = 0;
	int left = 0;

	list_for_each_entry(epdrv, &early_platform_driver_list, list) {
		/* only use drivers matching our class_str */
		if (strcmp(class_str, epdrv->class_str))
			continue;

		if (id == -2) {
			match_id = epdrv->requested_id;
			left = 1;

		} else {
			match_id = id;
			left += early_platform_left(epdrv, id);

			/* skip requested id */
			switch (epdrv->requested_id) {
			case EARLY_PLATFORM_ID_ERROR:
			case EARLY_PLATFORM_ID_UNSET:
				break;
			default:
				if (epdrv->requested_id == id)
					match_id = EARLY_PLATFORM_ID_UNSET;
			}
		}

		switch (match_id) {
		case EARLY_PLATFORM_ID_ERROR:
			pr_warning("%s: unable to parse %s parameter\n",
				   class_str, epdrv->pdrv->driver.name);
			/* fall-through */
		case EARLY_PLATFORM_ID_UNSET:
			match = NULL;
			break;
		default:
			match = early_platform_match(epdrv, match_id);
		}

		if (match) {
			/*
			 * Set up a sensible init_name to enable
			 * dev_name() and others to be used before the
			 * rest of the driver core is initialized.
			 */
			if (!match->dev.init_name && slab_is_available()) {
				if (match->id != -1)
					match->dev.init_name =
						kasprintf(GFP_KERNEL, "%s.%d",
							  match->name,
							  match->id);
				else
					match->dev.init_name =
						kasprintf(GFP_KERNEL, "%s",
							  match->name);

				if (!match->dev.init_name)
					return -ENOMEM;
			}

			if (epdrv->pdrv->probe(match))
				pr_warning("%s: unable to probe %s early.\n",
					   class_str, match->name);
			else
				n++;
		}

		if (n >= nr_probe)
			break;
	}

	if (left)
		return n;
	else
		return -ENODEV;
}

/**
 * early_platform_driver_probe - probe a class of registered drivers
 * @class_str: string to identify early platform driver class
 * @nr_probe: number of platform devices to successfully probe before exiting
 * @user_only: only probe user specified early platform devices
 *
 * Used by architecture code to probe registered early platform drivers
 * within a certain class. For probe to happen a registered early platform
 * device matching a registered early platform driver is needed.
 */
int __init early_platform_driver_probe(char *class_str,
				       int nr_probe,
				       int user_only)
{
	int k, n, i;

	n = 0;
	for (i = -2; n < nr_probe; i++) {
		k = early_platform_driver_probe_id(class_str, i, nr_probe - n);

		if (k < 0)
			break;

		n += k;

		if (user_only)
			break;
	}

	return n;
}

/**
 * early_platform_cleanup - clean up early platform code
 */
void __init early_platform_cleanup(void)
{
	struct platform_device *pd, *pd2;

	/* clean up the devres list used to chain devices */
	list_for_each_entry_safe(pd, pd2, &early_platform_device_list,
				 dev.devres_head) {
		list_del(&pd->dev.devres_head);
		memset(&pd->dev.devres_head, 0, sizeof(pd->dev.devres_head));
	}
}

Privacy Policy