aboutsummaryrefslogtreecommitdiff
path: root/drivers/base/regmap/regmap-debugfs.c
blob: 5799a0b9e6cc4168168bef46d864fbbe0db4020e (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
/*
 * Register map access API - debugfs
 *
 * Copyright 2011 Wolfson Microelectronics plc
 *
 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 as
 * published by the Free Software Foundation.
 */

#include <linux/slab.h>
#include <linux/mutex.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/device.h>
#include <linux/list.h>

#include "internal.h"

struct regmap_debugfs_node {
	struct regmap *map;
	const char *name;
	struct list_head link;
};

static struct dentry *regmap_debugfs_root;
static LIST_HEAD(regmap_debugfs_early_list);
static DEFINE_MUTEX(regmap_debugfs_early_lock);

/* Calculate the length of a fixed format  */
static size_t regmap_calc_reg_len(int max_val, char *buf, size_t buf_size)
{
	snprintf(buf, buf_size, "%x", max_val);
	return strlen(buf);
}

static ssize_t regmap_name_read_file(struct file *file,
				     char __user *user_buf, size_t count,
				     loff_t *ppos)
{
	struct regmap *map = file->private_data;
	int ret;
	char *buf;

	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name);
	if (ret < 0) {
		kfree(buf);
		return ret;
	}

	ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
	kfree(buf);
	return ret;
}

static const struct file_operations regmap_name_fops = {
	.open = simple_open,
	.read = regmap_name_read_file,
	.llseek = default_llseek,
};

static void regmap_debugfs_free_dump_cache(struct regmap *map)
{
	struct regmap_debugfs_off_cache *c;

	while (!list_empty(&map->debugfs_off_cache)) {
		c = list_first_entry(&map->debugfs_off_cache,
				     struct regmap_debugfs_off_cache,
				     list);
		list_del(&c->list);
		kfree(c);
	}
}

/*
 * Work out where the start offset maps into register numbers, bearing
 * in mind that we suppress hidden registers.
 */
static unsigned int regmap_debugfs_get_dump_start(struct regmap *map,
						  unsigned int base,
						  loff_t from,
						  loff_t *pos)
{
	struct regmap_debugfs_off_cache *c = NULL;
	loff_t p = 0;
	unsigned int i, ret;
	unsigned int fpos_offset;
	unsigned int reg_offset;

	/* Suppress the cache if we're using a subrange */
	if (base)
		return base;

	/*
	 * If we don't have a cache build one so we don't have to do a
	 * linear scan each time.
	 */
	mutex_lock(&map->cache_lock);
	i = base;
	if (list_empty(&map->debugfs_off_cache)) {
		for (; i <= map->max_register; i += map->reg_stride) {
			/* Skip unprinted registers, closing off cache entry */
			if (!regmap_readable(map, i) ||
			    regmap_precious(map, i)) {
				if (c) {
					c->max = p - 1;
					c->max_reg = i - map->reg_stride;
					list_add_tail(&c->list,
						      &map->debugfs_off_cache);
					c = NULL;
				}

				continue;
			}

			/* No cache entry?  Start a new one */
			if (!c) {
				c = kzalloc(sizeof(*c), GFP_KERNEL);
				if (!c) {
					regmap_debugfs_free_dump_cache(map);
					mutex_unlock(&map->cache_lock);
					return base;
				}
				c->min = p;
				c->base_reg = i;
			}

			p += map->debugfs_tot_len;
		}
	}

	/* Close the last entry off if we didn't scan beyond it */
	if (c) {
		c->max = p - 1;
		c->max_reg = i - map->reg_stride;
		list_add_tail(&c->list,
			      &map->debugfs_off_cache);
	}

	/*
	 * This should never happen; we return above if we fail to
	 * allocate and we should never be in this code if there are
	 * no registers at all.
	 */
	WARN_ON(list_empty(&map->debugfs_off_cache));
	ret = base;

	/* Find the relevant block:offset */
	list_for_each_entry(c, &map->debugfs_off_cache, list) {
		if (from >= c->min && from <= c->max) {
			fpos_offset = from - c->min;
			reg_offset = fpos_offset / map->debugfs_tot_len;
			*pos = c->min + (reg_offset * map->debugfs_tot_len);
			mutex_unlock(&map->cache_lock);
			return c->base_reg + (reg_offset * map->reg_stride);
		}

		*pos = c->max;
		ret = c->max_reg;
	}
	mutex_unlock(&map->cache_lock);

	return ret;
}

static inline void regmap_calc_tot_len(struct regmap *map,
				       void *buf, size_t count)
{
	/* Calculate the length of a fixed format  */
	if (!map->debugfs_tot_len) {
		map->debugfs_reg_len = regmap_calc_reg_len(map->max_register,
							   buf, count);
		map->debugfs_val_len = 2 * map->format.val_bytes;
		map->debugfs_tot_len = map->debugfs_reg_len +
			map->debugfs_val_len + 3;      /* : \n */
	}
}

static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
				   unsigned int to, char __user *user_buf,
				   size_t count, loff_t *ppos)
{
	size_t buf_pos = 0;
	loff_t p = *ppos;
	ssize_t ret;
	int i;
	char *buf;
	unsigned int val, start_reg;

	if (*ppos < 0 || !count)
		return -EINVAL;

	buf = kmalloc(count, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	regmap_calc_tot_len(map, buf, count);

	/* Work out which register we're starting at */
	start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p);

	for (i = start_reg; i <= to; i += map->reg_stride) {
		if (!regmap_readable(map, i))
			continue;

		if (regmap_precious(map, i))
			continue;

		/* If we're in the region the user is trying to read */
		if (p >= *ppos) {
			/* ...but not beyond it */
			if (buf_pos + map->debugfs_tot_len > count)
				break;

			/* Format the register */
			snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
				 map->debugfs_reg_len, i - from);
			buf_pos += map->debugfs_reg_len + 2;

			/* Format the value, write all X if we can't read */
			ret = regmap_read(map, i, &val);
			if (ret == 0)
				snprintf(buf + buf_pos, count - buf_pos,
					 "%.*x", map->debugfs_val_len, val);
			else
				memset(buf + buf_pos, 'X',
				       map->debugfs_val_len);
			buf_pos += 2 * map->format.val_bytes;

			buf[buf_pos++] = '\n';
		}
		p += map->debugfs_tot_len;
	}

	ret = buf_pos;

	if (copy_to_user(user_buf, buf, buf_pos)) {
		ret = -EFAULT;
		goto out;
	}

	*ppos += buf_pos;

out:
	kfree(buf);
	return ret;
}

static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
				    size_t count, loff_t *ppos)
{
	struct regmap *map = file->private_data;

	return regmap_read_debugfs(map, 0, map->max_register, user_buf,
				   count, ppos);
}

#undef REGMAP_ALLOW_WRITE_DEBUGFS
#ifdef REGMAP_ALLOW_WRITE_DEBUGFS
/*
 * This can be dangerous especially when we have clients such as
 * PMICs, therefore don't provide any real compile time configuration option
 * for this feature, people who want to use this will need to modify
 * the source code directly.
 */
static ssize_t regmap_map_write_file(struct file *file,
				     const char __user *user_buf,
				     size_t count, loff_t *ppos)
{
	char buf[32];
	size_t buf_size;
	char *start = buf;
	unsigned long reg, value;
	struct regmap *map = file->private_data;
	int ret;

	buf_size = min(count, (sizeof(buf)-1));
	if (copy_from_user(buf, user_buf, buf_size))
		return -EFAULT;
	buf[buf_size] = 0;

	while (*start == ' ')
		start++;
	reg = simple_strtoul(start, &start, 16);
	while (*start == ' ')
		start++;
	if (kstrtoul(start, 16, &value))
		return -EINVAL;

	/* Userspace has been fiddling around behind the kernel's back */
	add_taint(TAINT_USER, LOCKDEP_STILL_OK);

	ret = regmap_write(map, reg, value);
	if (ret < 0)
		return ret;
	return buf_size;
}
#else
#define regmap_map_write_file NULL
#endif

static const struct file_operations regmap_map_fops = {
	.open = simple_open,
	.read = regmap_map_read_file,
	.write = regmap_map_write_file,
	.llseek = default_llseek,
};

static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf,
				      size_t count, loff_t *ppos)
{
	struct regmap_range_node *range = file->private_data;
	struct regmap *map = range->map;

	return regmap_read_debugfs(map, range->range_min, range->range_max,
				   user_buf, count, ppos);
}

static const struct file_operations regmap_range_fops = {
	.open = simple_open,
	.read = regmap_range_read_file,
	.llseek = default_llseek,
};

static ssize_t regmap_reg_ranges_read_file(struct file *file,
					   char __user *user_buf, size_t count,
					   loff_t *ppos)
{
	struct regmap *map = file->private_data;
	struct regmap_debugfs_off_cache *c;
	loff_t p = 0;
	size_t buf_pos = 0;
	char *buf;
	char *entry;
	int ret;

	if (*ppos < 0 || !count)
		return -EINVAL;

	buf = kmalloc(count, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	entry = kmalloc(PAGE_SIZE, GFP_KERNEL);
	if (!entry) {
		kfree(buf);
		return -ENOMEM;
	}

	/* While we are at it, build the register dump cache
	 * now so the read() operation on the `registers' file
	 * can benefit from using the cache.  We do not care
	 * about the file position information that is contained
	 * in the cache, just about the actual register blocks */
	regmap_calc_tot_len(map, buf, count);
	regmap_debugfs_get_dump_start(map, 0, *ppos, &p);

	/* Reset file pointer as the fixed-format of the `registers'
	 * file is not compatible with the `range' file */
	p = 0;
	mutex_lock(&map->cache_lock);
	list_for_each_entry(c, &map->debugfs_off_cache, list) {
		snprintf(entry, PAGE_SIZE, "%x-%x",
			 c->base_reg, c->max_reg);
		if (p >= *ppos) {
			if (buf_pos + 1 + strlen(entry) > count)
				break;
			snprintf(buf + buf_pos, count - buf_pos,
				 "%s", entry);
			buf_pos += strlen(entry);
			buf[buf_pos] = '\n';
			buf_pos++;
		}
		p += strlen(entry) + 1;
	}
	mutex_unlock(&map->cache_lock);

	kfree(entry);
	ret = buf_pos;

	if (copy_to_user(user_buf, buf, buf_pos)) {
		ret = -EFAULT;
		goto out_buf;
	}

	*ppos += buf_pos;
out_buf:
	kfree(buf);
	return ret;
}

static const struct file_operations regmap_reg_ranges_fops = {
	.open = simple_open,
	.read = regmap_reg_ranges_read_file,
	.llseek = default_llseek,
};

static ssize_t regmap_access_read_file(struct file *file,
				       char __user *user_buf, size_t count,
				       loff_t *ppos)
{
	int reg_len, tot_len;
	size_t buf_pos = 0;
	loff_t p = 0;
	ssize_t ret;
	int i;
	struct regmap *map = file->private_data;
	char *buf;

	if (*ppos < 0 || !count)
		return -EINVAL;

	buf = kmalloc(count, GFP_KERNEL);
	if (!buf)
		return -ENOMEM;

	/* Calculate the length of a fixed format  */
	reg_len = regmap_calc_reg_len(map->max_register, buf, count);
	tot_len = reg_len + 10; /* ': R W V P\n' */

	for (i = 0; i <= map->max_register; i += map->reg_stride) {
		/* Ignore registers which are neither readable nor writable */
		if (!regmap_readable(map, i) && !regmap_writeable(map, i))
			continue;

		/* If we're in the region the user is trying to read */
		if (p >= *ppos) {
			/* ...but not beyond it */
			if (buf_pos >= count - 1 - tot_len)
				break;

			/* Format the register */
			snprintf(buf + buf_pos, count - buf_pos,
				 "%.*x: %c %c %c %c\n",
				 reg_len, i,
				 regmap_readable(map, i) ? 'y' : 'n',
				 regmap_writeable(map, i) ? 'y' : 'n',
				 regmap_volatile(map, i) ? 'y' : 'n',
				 regmap_precious(map, i) ? 'y' : 'n');

			buf_pos += tot_len;
		}
		p += tot_len;
	}

	ret = buf_pos;

	if (copy_to_user(user_buf, buf, buf_pos)) {
		ret = -EFAULT;
		goto out;
	}

	*ppos += buf_pos;

out:
	kfree(buf);
	return ret;
}

static const struct file_operations regmap_access_fops = {
	.open = simple_open,
	.read = regmap_access_read_file,
	.llseek = default_llseek,
};

void regmap_debugfs_init(struct regmap *map, const char *name)
{
	struct rb_node *next;
	struct regmap_range_node *range_node;
	const char *devname = "dummy";

	/* If we don't have the debugfs root yet, postpone init */
	if (!regmap_debugfs_root) {
		struct regmap_debugfs_node *node;
		node = kzalloc(sizeof(*node), GFP_KERNEL);
		if (!node)
			return;
		node->map = map;
		node->name = name;
		mutex_lock(&regmap_debugfs_early_lock);
		list_add(&node->link, &regmap_debugfs_early_list);
		mutex_unlock(&regmap_debugfs_early_lock);
		return;
	}

	INIT_LIST_HEAD(&map->debugfs_off_cache);
	mutex_init(&map->cache_lock);

	if (map->dev)
		devname = dev_name(map->dev);

	if (name) {
		map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
					      devname, name);
		name = map->debugfs_name;
	} else {
		name = devname;
	}

	map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
	if (!map->debugfs) {
		dev_warn(map->dev, "Failed to create debugfs directory\n");
		return;
	}

	debugfs_create_file("name", 0400, map->debugfs,
			    map, &regmap_name_fops);

	debugfs_create_file("range", 0400, map->debugfs,
			    map, &regmap_reg_ranges_fops);

	if (map->max_register || regmap_readable(map, 0)) {
		umode_t registers_mode;

		if (IS_ENABLED(REGMAP_ALLOW_WRITE_DEBUGFS))
			registers_mode = 0600;
		else
			registers_mode = 0400;

		debugfs_create_file("registers", registers_mode, map->debugfs,
				    map, &regmap_map_fops);
		debugfs_create_file("access", 0400, map->debugfs,
				    map, &regmap_access_fops);
	}

	if (map->cache_type) {
		debugfs_create_bool("cache_only", 0400, map->debugfs,
				    &map->cache_only);
		debugfs_create_bool("cache_dirty", 0400, map->debugfs,
				    &map->cache_dirty);
		debugfs_create_bool("cache_bypass", 0400, map->debugfs,
				    &map->cache_bypass);
	}

	next = rb_first(&map->range_tree);
	while (next) {
		range_node = rb_entry(next, struct regmap_range_node, node);

		if (range_node->name)
			debugfs_create_file(range_node->name, 0400,
					    map->debugfs, range_node,
					    &regmap_range_fops);

		next = rb_next(&range_node->node);
	}

	if (map->cache_ops && map->cache_ops->debugfs_init)
		map->cache_ops->debugfs_init(map);
}

void regmap_debugfs_exit(struct regmap *map)
{
	if (map->debugfs) {
		debugfs_remove_recursive(map->debugfs);
		mutex_lock(&map->cache_lock);
		regmap_debugfs_free_dump_cache(map);
		mutex_unlock(&map->cache_lock);
		kfree(map->debugfs_name);
	} else {
		struct regmap_debugfs_node *node, *tmp;

		mutex_lock(&regmap_debugfs_early_lock);
		list_for_each_entry_safe(node, tmp, &regmap_debugfs_early_list,
					 link) {
			if (node->map == map) {
				list_del(&node->link);
				kfree(node);
			}
		}
		mutex_unlock(&regmap_debugfs_early_lock);
	}
}

void regmap_debugfs_initcall(void)
{
	struct regmap_debugfs_node *node, *tmp;

	regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
	if (!regmap_debugfs_root) {
		pr_warn("regmap: Failed to create debugfs root\n");
		return;
	}

	mutex_lock(&regmap_debugfs_early_lock);
	list_for_each_entry_safe(node, tmp, &regmap_debugfs_early_list, link) {
		regmap_debugfs_init(node->map, node->name);
		list_del(&node->link);
		kfree(node);
	}
	mutex_unlock(&regmap_debugfs_early_lock);
}