summaryrefslogtreecommitdiff
path: root/drivers/pinctrl/core.c
blob: 79c56d90fcc59968c92280313fc1309805f370d8 (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
/*
 * Core driver for 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) "pinctrl core: " fmt

#include <linux/kernel.h>
#include <linux/export.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/sysfs.h>
#include <linux/debugfs.h>
#include <linux/seq_file.h>
#include <linux/pinctrl/pinctrl.h>
#include <linux/pinctrl/machine.h>
#include "core.h"
#include "pinmux.h"
#include "pinconf.h"

/* Global list of pin control devices */
static DEFINE_MUTEX(pinctrldev_list_mutex);
static LIST_HEAD(pinctrldev_list);

const char *pinctrl_dev_get_name(struct pinctrl_dev *pctldev)
{
	/* We're not allowed to register devices without name */
	return pctldev->desc->name;
}
EXPORT_SYMBOL_GPL(pinctrl_dev_get_name);

void *pinctrl_dev_get_drvdata(struct pinctrl_dev *pctldev)
{
	return pctldev->driver_data;
}
EXPORT_SYMBOL_GPL(pinctrl_dev_get_drvdata);

/**
 * get_pinctrl_dev_from_dev() - look up pin controller device
 * @dev: a device pointer, this may be NULL but then devname needs to be
 *	defined instead
 * @devname: the name of a device instance, as returned by dev_name(), this
 *	may be NULL but then dev needs to be defined instead
 *
 * Looks up a pin control device matching a certain device name or pure device
 * pointer, the pure device pointer will take precedence.
 */
struct pinctrl_dev *get_pinctrl_dev_from_dev(struct device *dev,
					     const char *devname)
{
	struct pinctrl_dev *pctldev = NULL;
	bool found = false;

	mutex_lock(&pinctrldev_list_mutex);
	list_for_each_entry(pctldev, &pinctrldev_list, node) {
		if (dev && pctldev->dev == dev) {
			/* Matched on device pointer */
			found = true;
			break;
		}

		if (devname &&
		    !strcmp(dev_name(pctldev->dev), devname)) {
			/* Matched on device name */
			found = true;
			break;
		}
	}
	mutex_unlock(&pinctrldev_list_mutex);

	return found ? pctldev : NULL;
}

struct pin_desc *pin_desc_get(struct pinctrl_dev *pctldev, unsigned int pin)
{
	struct pin_desc *pindesc;
	unsigned long flags;

	spin_lock_irqsave(&pctldev->pin_desc_tree_lock, flags);
	pindesc = radix_tree_lookup(&pctldev->pin_desc_tree, pin);
	spin_unlock_irqrestore(&pctldev->pin_desc_tree_lock, flags);

	return pindesc;
}

/**
 * pin_get_from_name() - look up a pin number from a name
 * @pctldev: the pin control device to lookup the pin on
 * @name: the name of the pin to look up
 */
int pin_get_from_name(struct pinctrl_dev *pctldev, const char *name)
{
	unsigned i, pin;

	/* 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);
		/* Pin space may be sparse */
		if (desc == NULL)
			continue;
		if (desc->name && !strcmp(name, desc->name))
			return pin;
	}

	return -EINVAL;
}

/**
 * pin_is_valid() - check if pin exists on controller
 * @pctldev: the pin control device to check the pin on
 * @pin: pin to check, use the local pin controller index number
 *
 * This tells us whether a certain pin exist on a certain pin controller or
 * not. Pin lists may be sparse, so some pins may not exist.
 */
bool pin_is_valid(struct pinctrl_dev *pctldev, int pin)
{
	struct pin_desc *pindesc;

	if (pin < 0)
		return false;

	pindesc = pin_desc_get(pctldev, pin);
	if (pindesc == NULL)
		return false;

	return true;
}
EXPORT_SYMBOL_GPL(pin_is_valid);

/* Deletes a range of pin descriptors */
static void pinctrl_free_pindescs(struct pinctrl_dev *pctldev,
				  const struct pinctrl_pin_desc *pins,
				  unsigned num_pins)
{
	int i;

	spin_lock(&pctldev->pin_desc_tree_lock);
	for (i = 0; i < num_pins; i++) {
		struct pin_desc *pindesc;

		pindesc = radix_tree_lookup(&pctldev->pin_desc_tree,
					    pins[i].number);
		if (pindesc != NULL) {
			radix_tree_delete(&pctldev->pin_desc_tree,
					  pins[i].number);
			if (pindesc->dynamic_name)
				kfree(pindesc->name);
		}
		kfree(pindesc);
	}
	spin_unlock(&pctldev->pin_desc_tree_lock);
}

static int pinctrl_register_one_pin(struct pinctrl_dev *pctldev,
				    unsigned number, const char *name)
{
	struct pin_desc *pindesc;

	pindesc = pin_desc_get(pctldev, number);
	if (pindesc != NULL) {
		pr_err("pin %d already registered on %s\n", number,
		       pctldev->desc->name);
		return -EINVAL;
	}

	pindesc = kzalloc(sizeof(*pindesc), GFP_KERNEL);
	if (pindesc == NULL)
		return -ENOMEM;

	spin_lock_init(&pindesc->lock);

	/* Set owner */
	pindesc->pctldev = pctldev;

	/* Copy basic pin info */
	if (pindesc->name) {
		pindesc->name = name;
	} else {
		pindesc->name = kasprintf(GFP_KERNEL, "PIN%u", number);
		if (pindesc->name == NULL)
			return -ENOMEM;
		pindesc->dynamic_name = true;
	}

	spin_lock(&pctldev->pin_desc_tree_lock);
	radix_tree_insert(&pctldev->pin_desc_tree, number, pindesc);
	spin_unlock(&pctldev->pin_desc_tree_lock);
	pr_debug("registered pin %d (%s) on %s\n",
		 number, pindesc->name, pctldev->desc->name);
	return 0;
}

static int pinctrl_register_pins(struct pinctrl_dev *pctldev,
				 struct pinctrl_pin_desc const *pins,
				 unsigned num_descs)
{
	unsigned i;
	int ret = 0;

	for (i = 0; i < num_descs; i++) {
		ret = pinctrl_register_one_pin(pctldev,
					       pins[i].number, pins[i].name);
		if (ret)
			return ret;
	}

	return 0;
}

/**
 * pinctrl_match_gpio_range() - check if a certain GPIO pin is in range
 * @pctldev: pin controller device to check
 * @gpio: gpio pin to check taken from the global GPIO pin space
 *
 * Tries to match a GPIO pin number to the ranges handled by a certain pin
 * controller, return the range or NULL
 */
static struct pinctrl_gpio_range *
pinctrl_match_gpio_range(struct pinctrl_dev *pctldev, unsigned gpio)
{
	struct pinctrl_gpio_range *range = NULL;

	/* Loop over the ranges */
	mutex_lock(&pctldev->gpio_ranges_lock);
	list_for_each_entry(range, &pctldev->gpio_ranges, node) {
		/* Check if we're in the valid range */
		if (gpio >= range->base &&
		    gpio < range->base + range->npins) {
			mutex_unlock(&pctldev->gpio_ranges_lock);
			return range;
		}
	}
	mutex_unlock(&pctldev->gpio_ranges_lock);

	return NULL;
}

/**
 * pinctrl_get_device_gpio_range() - find device for GPIO range
 * @gpio: the pin to locate the pin controller for
 * @outdev: the pin control device if found
 * @outrange: the GPIO range if found
 *
 * Find the pin controller handling a certain GPIO pin from the pinspace of
 * the GPIO subsystem, return the device and the matching GPIO range. Returns
 * negative if the GPIO range could not be found in any device.
 */
int pinctrl_get_device_gpio_range(unsigned gpio,
				struct pinctrl_dev **outdev,
				struct pinctrl_gpio_range **outrange)
{
	struct pinctrl_dev *pctldev = NULL;

	/* Loop over the pin controllers */
	mutex_lock(&pinctrldev_list_mutex);
	list_for_each_entry(pctldev, &pinctrldev_list, node) {
		struct pinctrl_gpio_range *range;

		range = pinctrl_match_gpio_range(pctldev, gpio);
		if (range != NULL) {
			*outdev = pctldev;
			*outrange = range;
			mutex_unlock(&pinctrldev_list_mutex);
			return 0;
		}
	}
	mutex_unlock(&pinctrldev_list_mutex);

	return -EINVAL;
}

/**
 * pinctrl_add_gpio_range() - register a GPIO range for a controller
 * @pctldev: pin controller device to add the range to
 * @range: the GPIO range to add
 *
 * This adds a range of GPIOs to be handled by a certain pin controller. Call
 * this to register handled ranges after registering your pin controller.
 */
void pinctrl_add_gpio_range(struct pinctrl_dev *pctldev,
			    struct pinctrl_gpio_range *range)
{
	mutex_lock(&pctldev->gpio_ranges_lock);
	list_add(&range->node, &pctldev->gpio_ranges);
	mutex_unlock(&pctldev->gpio_ranges_lock);
}

/**
 * pinctrl_remove_gpio_range() - remove a range of GPIOs fro a pin controller
 * @pctldev: pin controller device to remove the range from
 * @range: the GPIO range to remove
 */
void pinctrl_remove_gpio_range(struct pinctrl_dev *pctldev,
			       struct pinctrl_gpio_range *range)
{
	mutex_lock(&pctldev->gpio_ranges_lock);
	list_del(&range->node);
	mutex_unlock(&pctldev->gpio_ranges_lock);
}

/**
 * pinctrl_get_group_selector() - returns the group selector for a group
 * @pctldev: the pin controller handling the group
 * @pin_group: the pin group to look up
 */
int pinctrl_get_group_selector(struct pinctrl_dev *pctldev,
			       const char *pin_group)
{
	const struct pinctrl_ops *pctlops = pctldev->desc->pctlops;
	unsigned group_selector = 0;

	while (pctlops->list_groups(pctldev, group_selector) >= 0) {
		const char *gname = pctlops->get_group_name(pctldev,
							    group_selector);
		if (!strcmp(gname, pin_group)) {
			dev_dbg(pctldev->dev,
				"found group selector %u for %s\n",
				group_selector,
				pin_group);
			return group_selector;
		}

		group_selector++;
	}

	dev_err(pctldev->dev, "does not have pin group %s\n",
		pin_group);

	return -EINVAL;
}

#ifdef CONFIG_DEBUG_FS

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

	seq_printf(s, "registered pins: %d\n", pctldev->desc->npins);
	seq_printf(s, "max pin number: %d\n", pctldev->desc->maxpin);

	/* 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);
		/* Pin space may be sparse */
		if (desc == NULL)
			continue;

		seq_printf(s, "pin %d (%s) ", pin,
			   desc->name ? desc->name : "unnamed");

		/* Driver-specific info per pin */
		if (ops->pin_dbg_show)
			ops->pin_dbg_show(pctldev, s, pin);

		seq_puts(s, "\n");
	}

	return 0;
}

static int pinctrl_groups_show(struct seq_file *s, void *what)
{
	struct pinctrl_dev *pctldev = s->private;
	const struct pinctrl_ops *ops = pctldev->desc->pctlops;
	unsigned selector = 0;

	/* No grouping */
	if (!ops)
		return 0;

	seq_puts(s, "registered pin groups:\n");
	while (ops->list_groups(pctldev, selector) >= 0) {
		const unsigned *pins;
		unsigned num_pins;
		const char *gname = ops->get_group_name(pctldev, selector);
		int ret;
		int i;

		ret = ops->get_group_pins(pctldev, selector,
					  &pins, &num_pins);
		if (ret)
			seq_printf(s, "%s [ERROR GETTING PINS]\n",
				   gname);
		else {
			seq_printf(s, "group: %s, pins = [ ", gname);
			for (i = 0; i < num_pins; i++)
				seq_printf(s, "%d ", pins[i]);
			seq_puts(s, "]\n");
		}
		selector++;
	}


	return 0;
}

static int pinctrl_gpioranges_show(struct seq_file *s, void *what)
{
	struct pinctrl_dev *pctldev = s->private;
	struct pinctrl_gpio_range *range = NULL;

	seq_puts(s, "GPIO ranges handled:\n");

	/* Loop over the ranges */
	mutex_lock(&pctldev->gpio_ranges_lock);
	list_for_each_entry(range, &pctldev->gpio_ranges, node) {
		seq_printf(s, "%u: %s GPIOS [%u - %u] PINS [%u - %u]\n",
			   range->id, range->name,
			   range->base, (range->base + range->npins - 1),
			   range->pin_base,
			   (range->pin_base + range->npins - 1));
	}
	mutex_unlock(&pctldev->gpio_ranges_lock);

	return 0;
}

static int pinctrl_devices_show(struct seq_file *s, void *what)
{
	struct pinctrl_dev *pctldev;

	seq_puts(s, "name [pinmux] [pinconf]\n");
	mutex_lock(&pinctrldev_list_mutex);
	list_for_each_entry(pctldev, &pinctrldev_list, node) {
		seq_printf(s, "%s ", pctldev->desc->name);
		if (pctldev->desc->pmxops)
			seq_puts(s, "yes ");
		else
			seq_puts(s, "no ");
		if (pctldev->desc->confops)
			seq_puts(s, "yes");
		else
			seq_puts(s, "no");
		seq_puts(s, "\n");
	}
	mutex_unlock(&pinctrldev_list_mutex);

	return 0;
}

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

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

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

static int pinctrl_devices_open(struct inode *inode, struct file *file)
{
	return single_open(file, pinctrl_devices_show, NULL);
}

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

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

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

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

static struct dentry *debugfs_root;

static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev)
{
	static struct dentry *device_root;

	device_root = debugfs_create_dir(dev_name(pctldev->dev),
					 debugfs_root);
	if (IS_ERR(device_root) || !device_root) {
		pr_warn("failed to create debugfs directory for %s\n",
			dev_name(pctldev->dev));
		return;
	}
	debugfs_create_file("pins", S_IFREG | S_IRUGO,
			    device_root, pctldev, &pinctrl_pins_ops);
	debugfs_create_file("pingroups", S_IFREG | S_IRUGO,
			    device_root, pctldev, &pinctrl_groups_ops);
	debugfs_create_file("gpio-ranges", S_IFREG | S_IRUGO,
			    device_root, pctldev, &pinctrl_gpioranges_ops);
	pinmux_init_device_debugfs(device_root, pctldev);
	pinconf_init_device_debugfs(device_root, pctldev);
}

static void pinctrl_init_debugfs(void)
{
	debugfs_root = debugfs_create_dir("pinctrl", NULL);
	if (IS_ERR(debugfs_root) || !debugfs_root) {
		pr_warn("failed to create debugfs directory\n");
		debugfs_root = NULL;
		return;
	}

	debugfs_create_file("pinctrl-devices", S_IFREG | S_IRUGO,
			    debugfs_root, NULL, &pinctrl_devices_ops);
	pinmux_init_debugfs(debugfs_root);
}

#else /* CONFIG_DEBUG_FS */

static void pinctrl_init_device_debugfs(struct pinctrl_dev *pctldev)
{
}

static void pinctrl_init_debugfs(void)
{
}

#endif

/**
 * pinctrl_register() - register a pin controller device
 * @pctldesc: descriptor for this pin controller
 * @dev: parent device for this pin controller
 * @driver_data: private pin controller data for this pin controller
 */
struct pinctrl_dev *pinctrl_register(struct pinctrl_desc *pctldesc,
				    struct device *dev, void *driver_data)
{
	struct pinctrl_dev *pctldev;
	int ret;

	if (pctldesc == NULL)
		return NULL;
	if (pctldesc->name == NULL)
		return NULL;

	/* If we're implementing pinmuxing, check the ops for sanity */
	if (pctldesc->pmxops) {
		ret = pinmux_check_ops(pctldesc->pmxops);
		if (ret) {
			pr_err("%s pinmux ops lacks necessary functions\n",
			       pctldesc->name);
			return NULL;
		}
	}

	/* If we're implementing pinconfig, check the ops for sanity */
	if (pctldesc->confops) {
		ret = pinconf_check_ops(pctldesc->confops);
		if (ret) {
			pr_err("%s pin config ops lacks necessary functions\n",
			       pctldesc->name);
			return NULL;
		}
	}

	pctldev = kzalloc(sizeof(struct pinctrl_dev), GFP_KERNEL);
	if (pctldev == NULL)
		return NULL;

	/* Initialize pin control device struct */
	pctldev->owner = pctldesc->owner;
	pctldev->desc = pctldesc;
	pctldev->driver_data = driver_data;
	INIT_RADIX_TREE(&pctldev->pin_desc_tree, GFP_KERNEL);
	spin_lock_init(&pctldev->pin_desc_tree_lock);
	INIT_LIST_HEAD(&pctldev->gpio_ranges);
	mutex_init(&pctldev->gpio_ranges_lock);
	pctldev->dev = dev;

	/* Register all the pins */
	pr_debug("try to register %d pins on %s...\n",
		 pctldesc->npins, pctldesc->name);
	ret = pinctrl_register_pins(pctldev, pctldesc->pins, pctldesc->npins);
	if (ret) {
		pr_err("error during pin registration\n");
		pinctrl_free_pindescs(pctldev, pctldesc->pins,
				      pctldesc->npins);
		goto out_err;
	}

	pinctrl_init_device_debugfs(pctldev);
	mutex_lock(&pinctrldev_list_mutex);
	list_add(&pctldev->node, &pinctrldev_list);
	mutex_unlock(&pinctrldev_list_mutex);
	pinmux_hog_maps(pctldev);
	return pctldev;

out_err:
	kfree(pctldev);
	return NULL;
}
EXPORT_SYMBOL_GPL(pinctrl_register);

/**
 * pinctrl_unregister() - unregister pinmux
 * @pctldev: pin controller to unregister
 *
 * Called by pinmux drivers to unregister a pinmux.
 */
void pinctrl_unregister(struct pinctrl_dev *pctldev)
{
	if (pctldev == NULL)
		return;

	pinmux_unhog_maps(pctldev);
	/* TODO: check that no pinmuxes are still active? */
	mutex_lock(&pinctrldev_list_mutex);
	list_del(&pctldev->node);
	mutex_unlock(&pinctrldev_list_mutex);
	/* Destroy descriptor tree */
	pinctrl_free_pindescs(pctldev, pctldev->desc->pins,
			      pctldev->desc->npins);
	kfree(pctldev);
}
EXPORT_SYMBOL_GPL(pinctrl_unregister);

static int __init pinctrl_init(void)
{
	pr_info("initialized pinctrl subsystem\n");
	pinctrl_init_debugfs();
	return 0;
}

/* init early since many drivers really need to initialized pinmux early */
core_initcall(pinctrl_init);