aboutsummaryrefslogtreecommitdiffstats
path: root/drivers/pinctrl/pinmux.c
blob: 9248ce4efed4d446fefb3cc736b82ffe7c796a28 (plain) (blame)
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
/*
 * Core driver for the pin muxing portions of the pin control subsystem
 *
 * Copyright (C) 2011-2012 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>
 *
 * Copyright (C) 2012 NVIDIA CORPORATION. All rights reserved.
 *
 * 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/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"
#include "pinmux.h"

int pinmux_check_ops(struct pinctrl_dev *pctldev)
{
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	unsigned nfuncs;
	unsigned selector = 0;

	/* Check that we implement required operations */
	if (!ops ||
	    !ops->get_functions_count ||
	    !ops->get_function_name ||
	    !ops->get_function_groups ||
	    !ops->enable) {
		dev_err(pctldev->dev, "pinmux ops lacks necessary functions\n");
		return -EINVAL;
	}
	/* Check that all functions registered have names */
	nfuncs = ops->get_functions_count(pctldev);
	while (selector < nfuncs) {
		const char *fname = ops->get_function_name(pctldev,
							   selector);
		if (!fname) {
			dev_err(pctldev->dev, "pinmux ops has no name for function%u\n",
				selector);
			return -EINVAL;
		}
		selector++;
	}

	return 0;
}

int pinmux_validate_map(struct pinctrl_map const *map, int i)
{
	if (!map->data.mux.function) {
		pr_err("failed to register map %s (%d): no function given\n",
		       map->name, i);
		return -EINVAL;
	}

	return 0;
}

/**
 * pin_request() - request a single pin to be muxed in, typically for GPIO
 * @pin: the pin number in the global pin space
 * @owner: a representation of the owner of this pin; typically the device
 *	name that controls its mux function, or the requested GPIO name
 * @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 *owner,
		       struct pinctrl_gpio_range *gpio_range)
{
	struct pin_desc *desc;
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	int status = -EINVAL;

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

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

	if (gpio_range) {
		/* There's no need to support multiple GPIO requests */
		if (desc->gpio_owner) {
			dev_err(pctldev->dev,
				"pin %s already requested by %s; cannot claim for %s\n",
				desc->name, desc->gpio_owner, owner);
			goto out;
		}

		desc->gpio_owner = owner;
	} else {
		if (desc->mux_usecount && strcmp(desc->mux_owner, owner)) {
			dev_err(pctldev->dev,
				"pin %s already requested by %s; cannot claim for %s\n",
				desc->name, desc->mux_owner, owner);
			goto out;
		}

		desc->mux_usecount++;
		if (desc->mux_usecount > 1)
			return 0;

		desc->mux_owner = owner;
	}

	/* 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() failed for pin %d\n", pin);
		module_put(pctldev->owner);
	}

out_free_pin:
	if (status) {
		if (gpio_range) {
			desc->gpio_owner = NULL;
		} else {
			desc->mux_usecount--;
			if (!desc->mux_usecount)
				desc->mux_owner = NULL;
		}
	}
out:
	if (status)
		dev_err(pctldev->dev, "pin-%d (%s) status %d\n",
			pin, owner, 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 previous owner. This is used
 * for callers that dynamically allocate an owner 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 *owner;

	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 (!gpio_range) {
		/*
		 * A pin should not be freed more times than allocated.
		 */
		if (WARN_ON(!desc->mux_usecount))
			return NULL;
		desc->mux_usecount--;
		if (desc->mux_usecount)
			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);

	if (gpio_range) {
		owner = desc->gpio_owner;
		desc->gpio_owner = NULL;
	} else {
		owner = desc->mux_owner;
		desc->mux_owner = NULL;
		desc->mux_setting = NULL;
	}

	module_put(pctldev->owner);

	return owner;
}

/**
 * pinmux_request_gpio() - request pinmuxing for a GPIO pin
 * @pctldev: pin controller device affected
 * @pin: the pin to mux in for GPIO
 * @range: the applicable GPIO range
 */
int pinmux_request_gpio(struct pinctrl_dev *pctldev,
			struct pinctrl_gpio_range *range,
			unsigned pin, unsigned gpio)
{
	const char *owner;
	int ret;

	/* Conjure some name stating what chip and pin this is taken by */
	owner = kasprintf(GFP_KERNEL, "%s:%d", range->name, gpio);
	if (!owner)
		return -EINVAL;

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

	return ret;
}

/**
 * pinmux_free_gpio() - release a pin from GPIO muxing
 * @pctldev: the pin controller device for the pin
 * @pin: the affected currently GPIO-muxed in pin
 * @range: applicable GPIO range
 */
void pinmux_free_gpio(struct pinctrl_dev *pctldev, unsigned pin,
		      struct pinctrl_gpio_range *range)
{
	const char *owner;

	owner = pin_free(pctldev, pin, range);
	kfree(owner);
}

/**
 * pinmux_gpio_direction() - set the direction of a single muxed-in GPIO pin
 * @pctldev: the pin controller handling this pin
 * @range: applicable GPIO range
 * @pin: the affected GPIO pin in this controller
 * @input: true if we set the pin as input, false for output
 */
int pinmux_gpio_direction(struct pinctrl_dev *pctldev,
			  struct pinctrl_gpio_range *range,
			  unsigned pin, bool input)
{
	const struct pinmux_ops *ops;
	int ret;

	ops = pctldev->desc->pmxops;

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

	return ret;
}

static int pinmux_func_name_to_selector(struct pinctrl_dev *pctldev,
					const char *function)
{
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	unsigned nfuncs = ops->get_functions_count(pctldev);
	unsigned selector = 0;

	/* See if this pctldev has this function */
	while (selector < nfuncs) {
		const char *fname = ops->get_function_name(pctldev,
							   selector);

		if (!strcmp(function, fname))
			return selector;

		selector++;
	}

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

int pinmux_map_to_setting(struct pinctrl_map const *map,
			  struct pinctrl_setting *setting)
{
	struct pinctrl_dev *pctldev = setting->pctldev;
	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
	char const * const *groups;
	unsigned num_groups;
	int ret;
	const char *group;
	int i;

	if (!pmxops) {
		dev_err(pctldev->dev, "does not support mux function\n");
		return -EINVAL;
	}

	ret = pinmux_func_name_to_selector(pctldev, map->data.mux.function);
	if (ret < 0) {
		dev_err(pctldev->dev, "invalid function %s in map table\n",
			map->data.mux.function);
		return ret;
	}
	setting->data.mux.func = ret;

	ret = pmxops->get_function_groups(pctldev, setting->data.mux.func,
					  &groups, &num_groups);
	if (ret < 0) {
		dev_err(pctldev->dev, "can't query groups for function %s\n",
			map->data.mux.function);
		return ret;
	}
	if (!num_groups) {
		dev_err(pctldev->dev,
			"function %s can't be selected on any group\n",
			map->data.mux.function);
		return -EINVAL;
	}
	if (map->data.mux.group) {
		bool found = false;
		group = map->data.mux.group;
		for (i = 0; i < num_groups; i++) {
			if (!strcmp(group, groups[i])) {
				found = true;
				break;
			}
		}
		if (!found) {
			dev_err(pctldev->dev,
				"invalid group \"%s\" for function \"%s\"\n",
				group, map->data.mux.function);
			return -EINVAL;
		}
	} else {
		group = groups[0];
	}

	ret = pinctrl_get_group_selector(pctldev, group);
	if (ret < 0) {
		dev_err(pctldev->dev, "invalid group %s in map table\n",
			map->data.mux.group);
		return ret;
	}
	setting->data.mux.group = ret;

	return 0;
}

void pinmux_free_setting(struct pinctrl_setting const *setting)
{
	/* This function is currently unused */
}

int pinmux_enable_setting(struct pinctrl_setting const *setting)
{
	struct pinctrl_dev *pctldev = setting->pctldev;
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	int ret;
	const unsigned *pins;
	unsigned num_pins;
	int i;
	struct pin_desc *desc;

	ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
				      &pins, &num_pins);
	if (ret) {
		const char *gname;

		/* errors only affect debug data, so just warn */
		gname = pctlops->get_group_name(pctldev,
						setting->data.mux.group);
		dev_warn(pctldev->dev,
			 "could not get pins for group %s\n",
			 gname);
		num_pins = 0;
	}

	/* Try to allocate all pins in this group, one by one */
	for (i = 0; i < num_pins; i++) {
		ret = pin_request(pctldev, pins[i], setting->dev_name, NULL);
		if (ret) {
			const char *gname;
			const char *pname;

			desc = pin_desc_get(pctldev, pins[i]);
			pname = desc ? desc->name : "non-existing";
			gname = pctlops->get_group_name(pctldev,
						setting->data.mux.group);
			dev_err(pctldev->dev,
				"could not request pin %d (%s) from group %s "
				" on device %s\n",
				pins[i], pname, gname,
				pinctrl_dev_get_name(pctldev));
			goto err_pin_request;
		}
	}

	/* Now that we have acquired the pins, encode the mux setting */
	for (i = 0; i < num_pins; i++) {
		desc = pin_desc_get(pctldev, pins[i]);
		if (desc == NULL) {
			dev_warn(pctldev->dev,
				 "could not get pin desc for pin %d\n",
				 pins[i]);
			continue;
		}
		desc->mux_setting = &(setting->data.mux);
	}

	ret = ops->enable(pctldev, setting->data.mux.func,
			  setting->data.mux.group);

	if (ret)
		goto err_enable;

	return 0;

err_enable:
	for (i = 0; i < num_pins; i++) {
		desc = pin_desc_get(pctldev, pins[i]);
		if (desc)
			desc->mux_setting = NULL;
	}
err_pin_request:
	/* On error release all taken pins */
	while (--i >= 0)
		pin_free(pctldev, pins[i], NULL);

	return ret;
}

void pinmux_disable_setting(struct pinctrl_setting const *setting)
{
	struct pinctrl_dev *pctldev = setting->pctldev;
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
	const struct pinmux_ops *ops = pctldev->desc->pmxops;
	int ret;
	const unsigned *pins;
	unsigned num_pins;
	int i;
	struct pin_desc *desc;

	ret = pctlops->get_group_pins(pctldev, setting->data.mux.group,
				      &pins, &num_pins);
	if (ret) {
		const char *gname;

		/* errors only affect debug data, so just warn */
		gname = pctlops->get_group_name(pctldev,
						setting->data.mux.group);
		dev_warn(pctldev->dev,
			 "could not get pins for group %s\n",
			 gname);
		num_pins = 0;
	}

	/* Flag the descs that no setting is active */
	for (i = 0; i < num_pins; i++) {
		desc = pin_desc_get(pctldev, pins[i]);
		if (desc == NULL) {
			dev_warn(pctldev->dev,
				 "could not get pin desc for pin %d\n",
				 pins[i]);
			continue;
		}
		if (desc->mux_setting == &(setting->data.mux)) {
			desc->mux_setting = NULL;
			/* And release the pin */
			pin_free(pctldev, pins[i], NULL);
		} else {
			const char *gname;

			gname = pctlops->get_group_name(pctldev,
						setting->data.mux.group);
			dev_warn(pctldev->dev,
				 "not freeing pin %d (%s) as part of "
				 "deactivating group %s - it is already "
				 "used for some other setting",
				 pins[i], desc->name, gname);
		}
	}

	if (ops->disable)
		ops->disable(pctldev, setting->data.mux.func, setting->data.mux.group);
}

#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 nfuncs;
	unsigned func_selector = 0;

	if (!pmxops)
		return 0;

	mutex_lock(&pctldev->mutex);
	nfuncs = pmxops->get_functions_count(pctldev);
	while (func_selector < nfuncs) {
		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++;
	}

	mutex_unlock(&pctldev->mutex);

	return 0;
}

static int pinmux_pins_show(struct seq_file *s, void *what)
{
	struct pinctrl_dev *pctldev = s->private;
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
	unsigned i, pin;

	if (!pmxops)
		return 0;

	seq_puts(s, "Pinmux settings per pin\n");
	seq_puts(s, "Format: pin (name): mux_owner gpio_owner hog?\n");

	mutex_lock(&pctldev->mutex);

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

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

		if (desc->mux_owner &&
		    !strcmp(desc->mux_owner, pinctrl_dev_get_name(pctldev)))
			is_hog = true;

		seq_printf(s, "pin %d (%s): %s %s%s", pin,
			   desc->name ? desc->name : "unnamed",
			   desc->mux_owner ? desc->mux_owner
				: "(MUX UNCLAIMED)",
			   desc->gpio_owner ? desc->gpio_owner
				: "(GPIO UNCLAIMED)",
			   is_hog ? " (HOG)" : "");

		if (desc->mux_setting)
			seq_printf(s, " function %s group %s\n",
				   pmxops->get_function_name(pctldev,
					desc->mux_setting->func),
				   pctlops->get_group_name(pctldev,
					desc->mux_setting->group));
		else
			seq_printf(s, "\n");
	}

	mutex_unlock(&pctldev->mutex);

	return 0;
}

void pinmux_show_map(struct seq_file *s, struct pinctrl_map const *map)
{
	seq_printf(s, "group %s\nfunction %s\n",
		map->data.mux.group ? map->data.mux.group : "(default)",
		map->data.mux.function);
}

void pinmux_show_setting(struct seq_file *s,
			 struct pinctrl_setting const *setting)
{
	struct pinctrl_dev *pctldev = setting->pctldev;
	const struct pinmux_ops *pmxops = pctldev->desc->pmxops;
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;

	seq_printf(s, "group: %s (%u) function: %s (%u)\n",
		   pctlops->get_group_name(pctldev, setting->data.mux.group),
		   setting->data.mux.group,
		   pmxops->get_function_name(pctldev, setting->data.mux.func),
		   setting->data.mux.func);
}

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 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,
};

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);
}

#endif /* CONFIG_DEBUG_FS */