summaryrefslogtreecommitdiffstats
path: root/drivers/pinctrl/pinmux.c
blob: a76a348321bb4284d6820279fed3bb679cd23fcf (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
/*
 * Core driver for the pin muxing portions of the pin control subsystem
 *
 * Copyright (C) 2011 ST-Ericsson SA
 * Written on behalf of Linaro for ST-Ericsson
 * Based on bits of regulator core, gpio core and clk core
 *
 * Author: Linus Walleij <linus.walleij@linaro.org>
 *
 * License terms: GNU General Public License (GPL) version 2
 */
#define pr_fmt(fmt) "pinmux core: " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/slab.h>
#include <linux/radix-tree.h>
#include <linux/err.h>
#include <linux/list.h>
#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/machine.h>
#include <linux/pinctrl/pinmux.h>
#include "core.h"

/* List of pinmuxes */
static DEFINE_MUTEX(pinmux_list_mutex);
static LIST_HEAD(pinmux_list);

/* Global pinmux maps */
static struct pinmux_map *pinmux_maps;
static unsigned pinmux_maps_num;

/**
 * struct pinmux_group - group list item for pinmux groups
 * @node: pinmux group list node
 * @group_selector: the group selector for this group
 */
struct pinmux_group {
	struct list_head node;
	unsigned group_selector;
};

/**
 * struct pinmux - per-device pinmux state holder
 * @node: global list node
 * @dev: the device using this pinmux
 * @usecount: the number of active users of this mux setting, used to keep
 *	track of nested use cases
 * @pins: an array of discrete physical pins used in this mapping, taken
 *	from the global pin enumeration space (copied from pinmux map)
 * @num_pins: the number of pins in this mapping array, i.e. the number of
 *	elements in .pins so we can iterate over that array (copied from
 *	pinmux map)
 * @pctldev: pin control device handling this pinmux
 * @func_selector: the function selector for the pinmux device handling
 *	this pinmux
 * @groups: the group selectors for the pinmux device and
 *	selector combination handling this pinmux, this is a list that
 *	will be traversed on all pinmux operations such as
 *	get/put/enable/disable
 * @mutex: a lock for the pinmux state holder
 */
struct pinmux {
	struct list_head node;
	struct device *dev;
	unsigned usecount;
	struct pinctrl_dev *pctldev;
	unsigned func_selector;
	struct list_head groups;
	struct mutex mutex;
};

/**
 * struct pinmux_hog - a list item to stash mux hogs
 * @node: pinmux hog list node
 * @map: map entry responsible for this hogging
 * @pmx: the pinmux hogged by this item
 */
struct pinmux_hog {
	struct list_head node;
	struct pinmux_map const *map;
	struct pinmux *pmx;
};

/**
 * pin_request() - request a single pin to be muxed in, typically for GPIO
 * @pin: the pin number in the global pin space
 * @function: a functional name to give to this pin, passed to the driver
 *	so it knows what function to mux in, e.g. the string "gpioNN"
 *	means that you want to mux in the pin for use as GPIO number NN
 * @gpio_range: the range matching the GPIO pin if this is a request for a
 *	single GPIO pin
 */
static int pin_request(struct pinctrl_dev *pctldev,
		       int pin, const char *function,
		       struct pinctrl_gpio_range *gpio_range)
{
	struct pin_desc *desc;
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	int status = -EINVAL;

	dev_dbg(pctldev->dev, "request pin %d for %s\n", pin, function);

	desc = pin_desc_get(pctldev, pin);
	if (desc == NULL) {
		dev_err(pctldev->dev,
			"pin is not registered so it cannot be requested\n");
		goto out;
	}

	if (!function) {
		dev_err(pctldev->dev, "no function name given\n");
		return -EINVAL;
	}

	spin_lock(&desc->lock);
	if (desc->mux_function) {
		spin_unlock(&desc->lock);
		dev_err(pctldev->dev,
			"pin already requested\n");
		goto out;
	}
	desc->mux_function = function;
	spin_unlock(&desc->lock);

	/* Let each pin increase references to this module */
	if (!try_module_get(pctldev->owner)) {
		dev_err(pctldev->dev,
			"could not increase module refcount for pin %d\n",
			pin);
		status = -EINVAL;
		goto out_free_pin;
	}

	/*
	 * If there is no kind of request function for the pin we just assume
	 * we got it by default and proceed.
	 */
	if (gpio_range && ops->gpio_request_enable)
		/* This requests and enables a single GPIO pin */
		status = ops->gpio_request_enable(pctldev, gpio_range, pin);
	else if (ops->request)
		status = ops->request(pctldev, pin);
	else
		status = 0;

	if (status)
		dev_err(pctldev->dev, "->request on device %s failed "
		       "for pin %d\n",
		       pctldev->desc->name, pin);
out_free_pin:
	if (status) {
		spin_lock(&desc->lock);
		desc->mux_function = NULL;
		spin_unlock(&desc->lock);
	}
out:
	if (status)
		dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
		       pin, function ? : "?", status);

	return status;
}

/**
 * pin_free() - release a single muxed in pin so something else can be muxed
 * @pctldev: pin controller device handling this pin
 * @pin: the pin to free
 * @gpio_range: the range matching the GPIO pin if this is a request for a
 *	single GPIO pin
 *
 * This function returns a pointer to the function name in use. This is used
 * for callers that dynamically allocate a function name so it can be freed
 * once the pin is free. This is done for GPIO request functions.
 */
static const char *pin_free(struct pinctrl_dev *pctldev, int pin,
			    struct pinctrl_gpio_range *gpio_range)
{
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	struct pin_desc *desc;
	const char *func;

	desc = pin_desc_get(pctldev, pin);
	if (desc == NULL) {
		dev_err(pctldev->dev,
			"pin is not registered so it cannot be freed\n");
		return NULL;
	}

	/*
	 * If there is no kind of request function for the pin we just assume
	 * we got it by default and proceed.
	 */
	if (gpio_range && ops->gpio_disable_free)
		ops->gpio_disable_free(pctldev, gpio_range, pin);
	else if (ops->free)
		ops->free(pctldev, pin);

	spin_lock(&desc->lock);
	func = desc->mux_function;
	desc->mux_function = NULL;
	spin_unlock(&desc->lock);
	module_put(pctldev->owner);

	return func;
}

/**
 * pinmux_request_gpio() - request a single pin to be muxed in as GPIO
 * @gpio: the GPIO pin number from the GPIO subsystem number space
 *
 * This function should *ONLY* be used from gpiolib-based GPIO drivers,
 * as part of their gpio_request() semantics, platforms and individual drivers
 * shall *NOT* request GPIO pins to be muxed in.
 */
int pinmux_request_gpio(unsigned gpio)
{
	char gpiostr[16];
	const char *function;
	struct pinctrl_dev *pctldev;
	struct pinctrl_gpio_range *range;
	int ret;
	int pin;

	ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
	if (ret)
		return -EINVAL;

	/* Convert to the pin controllers number space */
	pin = gpio - range->base + range->pin_base;

	/* Conjure some name stating what chip and pin this is taken by */
	snprintf(gpiostr, 15, "%s:%d", range->name, gpio);

	function = kstrdup(gpiostr, GFP_KERNEL);
	if (!function)
		return -EINVAL;

	ret = pin_request(pctldev, pin, function, range);
	if (ret < 0)
		kfree(function);

	return ret;
}
EXPORT_SYMBOL_GPL(pinmux_request_gpio);

/**
 * pinmux_free_gpio() - free a single pin, currently used as GPIO
 * @gpio: the GPIO pin number from the GPIO subsystem number space
 *
 * This function should *ONLY* be used from gpiolib-based GPIO drivers,
 * as part of their gpio_free() semantics, platforms and individual drivers
 * shall *NOT* request GPIO pins to be muxed out.
 */
void pinmux_free_gpio(unsigned gpio)
{
	struct pinctrl_dev *pctldev;
	struct pinctrl_gpio_range *range;
	int ret;
	int pin;
	const char *func;

	ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
	if (ret)
		return;

	/* Convert to the pin controllers number space */
	pin = gpio - range->base + range->pin_base;

	func = pin_free(pctldev, pin, range);
	kfree(func);
}
EXPORT_SYMBOL_GPL(pinmux_free_gpio);

static int pinmux_gpio_direction(unsigned gpio, bool input)
{
	struct pinctrl_dev *pctldev;
	struct pinctrl_gpio_range *range;
	const struct pinmux_ops *ops;
	int ret;
	int pin;

	ret = pinctrl_get_device_gpio_range(gpio, &pctldev, &range);
	if (ret)
		return ret;

	ops = pctldev->desc->pmxops;

	/* Convert to the pin controllers number space */
	pin = gpio - range->base + range->pin_base;

	if (ops->gpio_set_direction)
		ret = ops->gpio_set_direction(pctldev, range, pin, input);
	else
		ret = 0;

	return ret;
}

/**
 * pinmux_gpio_direction_input() - request a GPIO pin to go into input mode
 * @gpio: the GPIO pin number from the GPIO subsystem number space
 *
 * This function should *ONLY* be used from gpiolib-based GPIO drivers,
 * as part of their gpio_direction_input() semantics, platforms and individual
 * drivers shall *NOT* touch pinmux GPIO calls.
 */
int pinmux_gpio_direction_input(unsigned gpio)
{
	return pinmux_gpio_direction(gpio, true);
}
EXPORT_SYMBOL_GPL(pinmux_gpio_direction_input);

/**
 * pinmux_gpio_direction_output() - request a GPIO pin to go into output mode
 * @gpio: the GPIO pin number from the GPIO subsystem number space
 *
 * This function should *ONLY* be used from gpiolib-based GPIO drivers,
 * as part of their gpio_direction_output() semantics, platforms and individual
 * drivers shall *NOT* touch pinmux GPIO calls.
 */
int pinmux_gpio_direction_output(unsigned gpio)
{
	return pinmux_gpio_direction(gpio, false);
}
EXPORT_SYMBOL_GPL(pinmux_gpio_direction_output);

/**
 * pinmux_register_mappings() - register a set of pinmux mappings
 * @maps: the pinmux mappings table to register, this should be marked with
 *	__initdata so it can be discarded after boot, this function will
 *	perform a shallow copy for the mapping entries.
 * @num_maps: the number of maps in the mapping table
 *
 * Only call this once during initialization of your machine, the function is
 * tagged as __init and won't be callable after init has completed. The map
 * passed into this function will be owned by the pinmux core and cannot be
 * freed.
 */
int __init pinmux_register_mappings(struct pinmux_map const *maps,
				    unsigned num_maps)
{
	void *tmp_maps;
	int i;

	pr_debug("add %d pinmux maps\n", num_maps);

	/* First sanity check the new mapping */
	for (i = 0; i < num_maps; i++) {
		if (!maps[i].name) {
			pr_err("failed to register map %d: "
			       "no map name given\n", i);
			return -EINVAL;
		}

		if (!maps[i].ctrl_dev && !maps[i].ctrl_dev_name) {
			pr_err("failed to register map %s (%d): "
			       "no pin control device given\n",
			       maps[i].name, i);
			return -EINVAL;
		}

		if (!maps[i].function) {
			pr_err("failed to register map %s (%d): "
			       "no function ID given\n", maps[i].name, i);
			return -EINVAL;
		}

		if (!maps[i].dev && !maps[i].dev_name)
			pr_debug("add system map %s function %s with no device\n",
				 maps[i].name,
				 maps[i].function);
		else
			pr_debug("register map %s, function %s\n",
				 maps[i].name,
				 maps[i].function);
	}

	/*
	 * Make a copy of the map array - string pointers will end up in the
	 * kernel const section anyway so these do not need to be deep copied.
	 */
	if (!pinmux_maps_num) {
		/* On first call, just copy them */
		tmp_maps = kmemdup(maps,
				   sizeof(struct pinmux_map) * num_maps,
				   GFP_KERNEL);
		if (!tmp_maps)
			return -ENOMEM;
	} else {
		/* Subsequent calls, reallocate array to new size */
		size_t oldsize = sizeof(struct pinmux_map) * pinmux_maps_num;
		size_t newsize = sizeof(struct pinmux_map) * num_maps;

		tmp_maps = krealloc(pinmux_maps, oldsize + newsize, GFP_KERNEL);
		if (!tmp_maps)
			return -ENOMEM;
		memcpy((tmp_maps + oldsize), maps, newsize);
	}

	pinmux_maps = tmp_maps;
	pinmux_maps_num += num_maps;
	return 0;
}

/**
 * acquire_pins() - acquire all the pins for a certain funcion on a pinmux
 * @pctldev: the device to take the pins on
 * @func_selector: the function selector to acquire the pins for
 * @group_selector: the group selector containing the pins to acquire
 */
static int acquire_pins(struct pinctrl_dev *pctldev,
			unsigned func_selector,
			unsigned group_selector)
{
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
	const char *func = pmxops->get_function_name(pctldev,
						     func_selector);
	const unsigned *pins;
	unsigned num_pins;
	int ret;
	int i;

	ret = pctlops->get_group_pins(pctldev, group_selector,
				      &pins, &num_pins);
	if (ret)
		return ret;

	dev_dbg(pctldev->dev, "requesting the %u pins from group %u\n",
		num_pins, group_selector);

	/* Try to allocate all pins in this group, one by one */
	for (i = 0; i < num_pins; i++) {
		ret = pin_request(pctldev, pins[i], func, NULL);
		if (ret) {
			dev_err(pctldev->dev,
				"could not get pin %d for function %s "
				"on device %s - conflicting mux mappings?\n",
				pins[i], func ? : "(undefined)",
				pinctrl_dev_get_name(pctldev));
			/* On error release all taken pins */
			i--; /* this pin just failed */
			for (; i >= 0; i--)
				pin_free(pctldev, pins[i], NULL);
			return -ENODEV;
		}
	}
	return 0;
}

/**
 * release_pins() - release pins taken by earlier acquirement
 * @pctldev: the device to free the pinx on
 * @group_selector: the group selector containing the pins to free
 */
static void release_pins(struct pinctrl_dev *pctldev,
			 unsigned group_selector)
{
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
	const unsigned *pins;
	unsigned num_pins;
	int ret;
	int i;

	ret = pctlops->get_group_pins(pctldev, group_selector,
				      &pins, &num_pins);
	if (ret) {
		dev_err(pctldev->dev, "could not get pins to release for "
			"group selector %d\n",
			group_selector);
		return;
	}
	for (i = 0; i < num_pins; i++)
		pin_free(pctldev, pins[i], NULL);
}

/**
 * pinmux_check_pin_group() - check function and pin group combo
 * @pctldev: device to check the pin group vs function for
 * @func_selector: the function selector to check the pin group for, we have
 *	already looked this up in the calling function
 * @pin_group: the pin group to match to the function
 *
 * This function will check that the pinmux driver can supply the
 * selected pin group for a certain function, returns the group selector if
 * the group and function selector will work fine together, else returns
 * negative
 */
static int pinmux_check_pin_group(struct pinctrl_dev *pctldev,
				  unsigned func_selector,
				  const char *pin_group)
{
	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
	int ret;

	/*
	 * If the driver does not support different pin groups for the
	 * functions, we only support group 0, and assume this exists.
	 */
	if (!pctlops || !pctlops->list_groups)
		return 0;

	/*
	 * Passing NULL (no specific group) will select the first and
	 * hopefully only group of pins available for this function.
	 */
	if (!pin_group) {
		char const * const *groups;
		unsigned num_groups;

		ret = pmxops->get_function_groups(pctldev, func_selector,
						  &groups, &num_groups);
		if (ret)
			return ret;
		if (num_groups < 1)
			return -EINVAL;
		ret = pinctrl_get_group_selector(pctldev, groups[0]);
		if (ret < 0) {
			dev_err(pctldev->dev,
				"function %s wants group %s but the pin "
				"controller does not seem to have that group\n",
				pmxops->get_function_name(pctldev, func_selector),
				groups[0]);
			return ret;
		}

		if (num_groups > 1)
			dev_dbg(pctldev->dev,
				"function %s support more than one group, "
				"default-selecting first group %s (%d)\n",
				pmxops->get_function_name(pctldev, func_selector),
				groups[0],
				ret);

		return ret;
	}

	dev_dbg(pctldev->dev,
		"check if we have pin group %s on controller %s\n",
		pin_group, pinctrl_dev_get_name(pctldev));

	ret = pinctrl_get_group_selector(pctldev, pin_group);
	if (ret < 0) {
		dev_dbg(pctldev->dev,
			"%s does not support pin group %s with function %s\n",
			pinctrl_dev_get_name(pctldev),
			pin_group,
			pmxops->get_function_name(pctldev, func_selector));
	}
	return ret;
}

/**
 * pinmux_search_function() - check pin control driver for a certain function
 * @pctldev: device to check for function and position
 * @map: function map containing the function and position to look for
 * @func_selector: returns the applicable function selector if found
 * @group_selector: returns the applicable group selector if found
 *
 * This will search the pinmux driver for an applicable
 * function with a specific pin group, returns 0 if these can be mapped
 * negative otherwise
 */
static int pinmux_search_function(struct pinctrl_dev *pctldev,
				  struct pinmux_map const *map,
				  unsigned *func_selector,
				  unsigned *group_selector)
{
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	unsigned selector = 0;

	/* See if this pctldev has this function */
	while (ops->list_functions(pctldev, selector) >= 0) {
		const char *fname = ops->get_function_name(pctldev,
							   selector);
		int ret;

		if (!strcmp(map->function, fname)) {
			/* Found the function, check pin group */
			ret = pinmux_check_pin_group(pctldev, selector,
						     map->group);
			if (ret < 0)
				return ret;

			/* This function and group selector can be used */
			*func_selector = selector;
			*group_selector = ret;
			return 0;

		}
		selector++;
	}

	pr_err("%s does not support function %s\n",
	       pinctrl_dev_get_name(pctldev), map->function);
	return -EINVAL;
}

/**
 * pinmux_enable_muxmap() - enable a map entry for a certain pinmux
 */
static int pinmux_enable_muxmap(struct pinctrl_dev *pctldev,
				struct pinmux *pmx,
				struct device *dev,
				const char *devname,
				struct pinmux_map const *map)
{
	unsigned func_selector;
	unsigned group_selector;
	struct pinmux_group *grp;
	int ret;

	/*
	 * Note that we're not locking the pinmux mutex here, because
	 * this is only called at pinmux initialization time when it
	 * has not been added to any list and thus is not reachable
	 * by anyone else.
	 */

	if (pmx->pctldev && pmx->pctldev != pctldev) {
		dev_err(pctldev->dev,
			"different pin control devices given for device %s, "
			"function %s\n",
			devname,
			map->function);
		return -EINVAL;
	}
	pmx->dev = dev;
	pmx->pctldev = pctldev;

	/* Now go into the driver and try to match a function and group */
	ret = pinmux_search_function(pctldev, map, &func_selector,
				     &group_selector);
	if (ret < 0)
		return ret;

	/*
	 * If the function selector is already set, it needs to be identical,
	 * we support several groups with one function but not several
	 * functions with one or several groups in the same pinmux.
	 */
	if (pmx->func_selector != UINT_MAX &&
	    pmx->func_selector != func_selector) {
		dev_err(pctldev->dev,
			"dual function defines in the map for device %s\n",
		       devname);
		return -EINVAL;
	}
	pmx->func_selector = func_selector;

	/* Now add this group selector, we may have many of them */
	grp = kmalloc(sizeof(struct pinmux_group), GFP_KERNEL);
	if (!grp)
		return -ENOMEM;
	grp->group_selector = group_selector;
	ret = acquire_pins(pctldev, func_selector, group_selector);
	if (ret) {
		kfree(grp);
		return ret;
	}
	list_add(&grp->node, &pmx->groups);

	return 0;
}

static void pinmux_free_groups(struct pinmux *pmx)
{
	struct list_head *node, *tmp;

	list_for_each_safe(node, tmp, &pmx->groups) {
		struct pinmux_group *grp =
			list_entry(node, struct pinmux_group, node);
		/* Release all pins taken by this group */
		release_pins(pmx->pctldev, grp->group_selector);
		list_del(node);
		kfree(grp);
	}
}

/**
 * pinmux_get() - retrieves the pinmux for a certain device
 * @dev: the device to get the pinmux for
 * @name: an optional specific mux mapping name or NULL, the name is only
 *	needed if you want to have more than one mapping per device, or if you
 *	need an anonymous pinmux (not tied to any specific device)
 */
struct pinmux *pinmux_get(struct device *dev, const char *name)
{

	struct pinmux_map const *map = NULL;
	struct pinctrl_dev *pctldev = NULL;
	const char *devname = NULL;
	struct pinmux *pmx;
	bool found_map;
	unsigned num_maps = 0;
	int ret = -ENODEV;
	int i;

	/* We must have dev or ID or both */
	if (!dev && !name)
		return ERR_PTR(-EINVAL);

	if (dev)
		devname = dev_name(dev);

	pr_debug("get mux %s for device %s\n", name,
		 devname ? devname : "(none)");

	/*
	 * create the state cookie holder struct pinmux for each
	 * mapping, this is what consumers will get when requesting
	 * a pinmux handle with pinmux_get()
	 */
	pmx = kzalloc(sizeof(struct pinmux), GFP_KERNEL);
	if (pmx == NULL)
		return ERR_PTR(-ENOMEM);
	mutex_init(&pmx->mutex);
	pmx->func_selector = UINT_MAX;
	INIT_LIST_HEAD(&pmx->groups);

	/* Iterate over the pinmux maps to locate the right ones */
	for (i = 0; i < pinmux_maps_num; i++) {
		map = &pinmux_maps[i];
		found_map = false;

		/*
		 * First, try to find the pctldev given in the map
		 */
		pctldev = get_pinctrl_dev_from_dev(map->ctrl_dev,
						   map->ctrl_dev_name);
		if (!pctldev) {
			const char *devname = NULL;

			if (map->ctrl_dev)
				devname = dev_name(map->ctrl_dev);
			else if (map->ctrl_dev_name)
				devname = map->ctrl_dev_name;

			pr_warning("could not find a pinctrl device for pinmux "
				   "function %s, fishy, they shall all have one\n",
				   map->function);
			pr_warning("given pinctrl device name: %s",
				   devname ? devname : "UNDEFINED");

			/* Continue to check the other mappings anyway... */
			continue;
		}

		pr_debug("in map, found pctldev %s to handle function %s",
			 dev_name(pctldev->dev), map->function);


		/*
		 * If we're looking for a specific named map, this must match,
		 * else we loop and look for the next.
		 */
		if (name != NULL) {
			if (map->name == NULL)
				continue;
			if (strcmp(map->name, name))
				continue;
		}

		/*
		 * This is for the case where no device name is given, we
		 * already know that the function name matches from above
		 * code.
		 */
		if (!map->dev_name && (name != NULL))
			found_map = true;

		/* If the mapping has a device set up it must match */
		if (map->dev_name &&
		    (!devname || !strcmp(map->dev_name, devname)))
			/* MATCH! */
			found_map = true;

		/* If this map is applicable, then apply it */
		if (found_map) {
			ret = pinmux_enable_muxmap(pctldev, pmx, dev,
						   devname, map);
			if (ret) {
				pinmux_free_groups(pmx);
				kfree(pmx);
				return ERR_PTR(ret);
			}
			num_maps++;
		}
	}


	/* We should have atleast one map, right */
	if (!num_maps) {
		pr_err("could not find any mux maps for device %s, ID %s\n",
		       devname ? devname : "(anonymous)",
		       name ? name : "(undefined)");
		kfree(pmx);
		return ERR_PTR(-EINVAL);
	}

	pr_debug("found %u mux maps for device %s, UD %s\n",
		 num_maps,
		 devname ? devname : "(anonymous)",
		 name ? name : "(undefined)");

	/* Add the pinmux to the global list */
	mutex_lock(&pinmux_list_mutex);
	list_add(&pmx->node, &pinmux_list);
	mutex_unlock(&pinmux_list_mutex);

	return pmx;
}
EXPORT_SYMBOL_GPL(pinmux_get);

/**
 * pinmux_put() - release a previously claimed pinmux
 * @pmx: a pinmux previously claimed by pinmux_get()
 */
void pinmux_put(struct pinmux *pmx)
{
	if (pmx == NULL)
		return;

	mutex_lock(&pmx->mutex);
	if (pmx->usecount)
		pr_warn("releasing pinmux with active users!\n");
	/* Free the groups and all acquired pins */
	pinmux_free_groups(pmx);
	mutex_unlock(&pmx->mutex);

	/* Remove from list */
	mutex_lock(&pinmux_list_mutex);
	list_del(&pmx->node);
	mutex_unlock(&pinmux_list_mutex);

	kfree(pmx);
}
EXPORT_SYMBOL_GPL(pinmux_put);

/**
 * pinmux_enable() - enable a certain pinmux setting
 * @pmx: the pinmux to enable, previously claimed by pinmux_get()
 */
int pinmux_enable(struct pinmux *pmx)
{
	int ret = 0;

	if (pmx == NULL)
		return -EINVAL;
	mutex_lock(&pmx->mutex);
	if (pmx->usecount++ == 0) {
		struct pinctrl_dev *pctldev = pmx->pctldev;
		const struct pinmux_ops *ops = pctldev->desc->pmxops;
		struct pinmux_group *grp;

		list_for_each_entry(grp, &pmx->groups, node) {
			ret = ops->enable(pctldev, pmx->func_selector,
					  grp->group_selector);
			if (ret) {
				/*
				 * TODO: call disable() on all groups we called
				 * enable() on to this point?
				 */
				pmx->usecount--;
				break;
			}
		}
	}
	mutex_unlock(&pmx->mutex);
	return ret;
}
EXPORT_SYMBOL_GPL(pinmux_enable);

/**
 * pinmux_disable() - disable a certain pinmux setting
 * @pmx: the pinmux to disable, previously claimed by pinmux_get()
 */
void pinmux_disable(struct pinmux *pmx)
{
	if (pmx == NULL)
		return;

	mutex_lock(&pmx->mutex);
	if (--pmx->usecount == 0) {
		struct pinctrl_dev *pctldev = pmx->pctldev;
		const struct pinmux_ops *ops = pctldev->desc->pmxops;
		struct pinmux_group *grp;

		list_for_each_entry(grp, &pmx->groups, node) {
			ops->disable(pctldev, pmx->func_selector,
				     grp->group_selector);
		}
	}
	mutex_unlock(&pmx->mutex);
}
EXPORT_SYMBOL_GPL(pinmux_disable);

int pinmux_check_ops(const struct pinmux_ops *ops)
{
	/* Check that we implement required operations */
	if (!ops->list_functions ||
	    !ops->get_function_name ||
	    !ops->get_function_groups ||
	    !ops->enable ||
	    !ops->disable)
		return -EINVAL;

	return 0;
}

/* Hog a single map entry and add to the hoglist */
static int pinmux_hog_map(struct pinctrl_dev *pctldev,
			  struct pinmux_map const *map)
{
	struct pinmux_hog *hog;
	struct pinmux *pmx;
	int ret;

	if (map->dev || map->dev_name) {
		/*
		 * TODO: the day we have device tree support, we can
		 * traverse the device tree and hog to specific device nodes
		 * without any problems, so then we can hog pinmuxes for
		 * all devices that just want a static pin mux at this point.
		 */
		dev_err(pctldev->dev, "map %s wants to hog a non-system "
			"pinmux, this is not going to work\n", map->name);
		return -EINVAL;
	}

	hog = kzalloc(sizeof(struct pinmux_hog), GFP_KERNEL);
	if (!hog)
		return -ENOMEM;

	pmx = pinmux_get(NULL, map->name);
	if (IS_ERR(pmx)) {
		kfree(hog);
		dev_err(pctldev->dev,
			"could not get the %s pinmux mapping for hogging\n",
			map->name);
		return PTR_ERR(pmx);
	}

	ret = pinmux_enable(pmx);
	if (ret) {
		pinmux_put(pmx);
		kfree(hog);
		dev_err(pctldev->dev,
			"could not enable the %s pinmux mapping for hogging\n",
			map->name);
		return ret;
	}

	hog->map = map;
	hog->pmx = pmx;

	dev_info(pctldev->dev, "hogged map %s, function %s\n", map->name,
		 map->function);
	mutex_lock(&pctldev->pinmux_hogs_lock);
	list_add(&hog->node, &pctldev->pinmux_hogs);
	mutex_unlock(&pctldev->pinmux_hogs_lock);

	return 0;
}

/**
 * pinmux_hog_maps() - hog specific map entries on controller device
 * @pctldev: the pin control device to hog entries on
 *
 * When the pin controllers are registered, there may be some specific pinmux
 * map entries that need to be hogged, i.e. get+enabled until the system shuts
 * down.
 */
int pinmux_hog_maps(struct pinctrl_dev *pctldev)
{
	struct device *dev = pctldev->dev;
	const char *devname = dev_name(dev);
	int ret;
	int i;

	INIT_LIST_HEAD(&pctldev->pinmux_hogs);
	mutex_init(&pctldev->pinmux_hogs_lock);

	for (i = 0; i < pinmux_maps_num; i++) {
		struct pinmux_map const *map = &pinmux_maps[i];

		if (((map->ctrl_dev == dev) ||
		     !strcmp(map->ctrl_dev_name, devname)) &&
		    map->hog_on_boot) {
			/* OK time to hog! */
			ret = pinmux_hog_map(pctldev, map);
			if (ret)
				return ret;
		}
	}
	return 0;
}

/**
 * pinmux_unhog_maps() - unhog specific map entries on controller device
 * @pctldev: the pin control device to unhog entries on
 */
void pinmux_unhog_maps(struct pinctrl_dev *pctldev)
{
	struct list_head *node, *tmp;

	mutex_lock(&pctldev->pinmux_hogs_lock);
	list_for_each_safe(node, tmp, &pctldev->pinmux_hogs) {
		struct pinmux_hog *hog =
			list_entry(node, struct pinmux_hog, node);
		pinmux_disable(hog->pmx);
		pinmux_put(hog->pmx);
		list_del(node);
		kfree(hog);
	}
	mutex_unlock(&pctldev->pinmux_hogs_lock);
}

#ifdef CONFIG_DEBUG_FS

/* Called from pincontrol core */
static int pinmux_functions_show(struct seq_file *s, void *what)
{
	struct pinctrl_dev *pctldev = s->private;
	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
	unsigned func_selector = 0;

	while (pmxops->list_functions(pctldev, func_selector) >= 0) {
		const char *func = pmxops->get_function_name(pctldev,
							  func_selector);
		const char * const *groups;
		unsigned num_groups;
		int ret;
		int i;

		ret = pmxops->get_function_groups(pctldev, func_selector,
						  &groups, &num_groups);
		if (ret)
			seq_printf(s, "function %s: COULD NOT GET GROUPS\n",
				   func);

		seq_printf(s, "function: %s, groups = [ ", func);
		for (i = 0; i < num_groups; i++)
			seq_printf(s, "%s ", groups[i]);
		seq_puts(s, "]\n");

		func_selector++;

	}

	return 0;
}

static int pinmux_pins_show(struct seq_file *s, void *what)
{
	struct pinctrl_dev *pctldev = s->private;
	unsigned i, pin;

	seq_puts(s, "Pinmux settings per pin\n");
	seq_puts(s, "Format: pin (name): pinmuxfunction\n");

	/* The pin number can be retrived from the pin controller descriptor */
	for (i = 0; i < pctldev->desc->npins; i++) {

		struct pin_desc *desc;

		pin = pctldev->desc->pins[i].number;
		desc = pin_desc_get(pctldev, pin);
		/* Skip if we cannot search the pin */
		if (desc == NULL)
			continue;

		seq_printf(s, "pin %d (%s): %s\n", pin,
			   desc->name ? desc->name : "unnamed",
			   desc->mux_function ? desc->mux_function
					      : "UNCLAIMED");
	}

	return 0;
}

static int pinmux_hogs_show(struct seq_file *s, void *what)
{
	struct pinctrl_dev *pctldev = s->private;
	struct pinmux_hog *hog;

	seq_puts(s, "Pinmux map hogs held by device\n");

	list_for_each_entry(hog, &pctldev->pinmux_hogs, node)
		seq_printf(s, "%s\n", hog->map->name);

	return 0;
}

static int pinmux_show(struct seq_file *s, void *what)
{
	struct pinmux *pmx;

	seq_puts(s, "Requested pinmuxes and their maps:\n");
	list_for_each_entry(pmx, &pinmux_list, node) {
		struct pinctrl_dev *pctldev = pmx->pctldev;
		const struct pinmux_ops *pmxops;
		const struct pinctrl_ops *pctlops;
		struct pinmux_group *grp;

		if (!pctldev) {
			seq_puts(s, "NO PIN CONTROLLER DEVICE\n");
			continue;
		}

		pmxops = pctldev->desc->pmxops;
		pctlops = pctldev->desc->pctlops;

		seq_printf(s, "device: %s function: %s (%u),",
			   pinctrl_dev_get_name(pmx->pctldev),
			   pmxops->get_function_name(pctldev, pmx->func_selector),
			   pmx->func_selector);

		seq_printf(s, " groups: [");
		list_for_each_entry(grp, &pmx->groups, node) {
			seq_printf(s, " %s (%u)",
				   pctlops->get_group_name(pctldev, grp->group_selector),
				   grp->group_selector);
		}
		seq_printf(s, " ]");

		seq_printf(s, " users: %u map-> %s\n",
			   pmx->usecount,
			   pmx->dev ? dev_name(pmx->dev) : "(system)");
	}

	return 0;
}

static int pinmux_maps_show(struct seq_file *s, void *what)
{
	int i;

	seq_puts(s, "Pinmux maps:\n");

	for (i = 0; i < pinmux_maps_num; i++) {
		struct pinmux_map const *map = &pinmux_maps[i];

		seq_printf(s, "%s:\n", map->name);
		if (map->dev || map->dev_name)
			seq_printf(s, "  device: %s\n",
				   map->dev ? dev_name(map->dev) :
				   map->dev_name);
		else
			seq_printf(s, "  SYSTEM MUX\n");
		seq_printf(s, "  controlling device %s\n",
			   map->ctrl_dev ? dev_name(map->ctrl_dev) :
			   map->ctrl_dev_name);
		seq_printf(s, "  function: %s\n", map->function);
		seq_printf(s, "  group: %s\n", map->group ? map->group :
			   "(default)");
	}
	return 0;
}

static int pinmux_functions_open(struct inode *inode, struct file *file)
{
	return single_open(file, pinmux_functions_show, inode->i_private);
}

static int pinmux_pins_open(struct inode *inode, struct file *file)
{
	return single_open(file, pinmux_pins_show, inode->i_private);
}

static int pinmux_hogs_open(struct inode *inode, struct file *file)
{
	return single_open(file, pinmux_hogs_show, inode->i_private);
}

static int pinmux_open(struct inode *inode, struct file *file)
{
	return single_open(file, pinmux_show, NULL);
}

static int pinmux_maps_open(struct inode *inode, struct file *file)
{
	return single_open(file, pinmux_maps_show, NULL);
}

static const struct file_operations pinmux_functions_ops = {
	.open		= pinmux_functions_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct file_operations pinmux_pins_ops = {
	.open		= pinmux_pins_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct file_operations pinmux_hogs_ops = {
	.open		= pinmux_hogs_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct file_operations pinmux_ops = {
	.open		= pinmux_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

static const struct file_operations pinmux_maps_ops = {
	.open		= pinmux_maps_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
	.release	= single_release,
};

void pinmux_init_device_debugfs(struct dentry *devroot,
			 struct pinctrl_dev *pctldev)
{
	debugfs_create_file("pinmux-functions", S_IFREG | S_IRUGO,
			    devroot, pctldev, &pinmux_functions_ops);
	debugfs_create_file("pinmux-pins", S_IFREG | S_IRUGO,
			    devroot, pctldev, &pinmux_pins_ops);
	debugfs_create_file("pinmux-hogs", S_IFREG | S_IRUGO,
			    devroot, pctldev, &pinmux_hogs_ops);
}

void pinmux_init_debugfs(struct dentry *subsys_root)
{
	debugfs_create_file("pinmuxes", S_IFREG | S_IRUGO,
			    subsys_root, NULL, &pinmux_ops);
	debugfs_create_file("pinmux-maps", S_IFREG | S_IRUGO,
			    subsys_root, NULL, &pinmux_maps_ops);
}

#endif /* CONFIG_DEBUG_FS */
OpenPOWER on IntegriCloud