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1// SPDX-License-Identifier: GPL-2.0
2//
3// Register map access API - debugfs
4//
5// Copyright 2011 Wolfson Microelectronics plc
6//
7// Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
8
9#include <linux/slab.h>
10#include <linux/mutex.h>
11#include <linux/debugfs.h>
12#include <linux/uaccess.h>
13#include <linux/device.h>
14#include <linux/list.h>
15
16#include "internal.h"
17
18struct regmap_debugfs_node {
19 struct regmap *map;
20 struct list_head link;
21};
22
23static unsigned int dummy_index;
24static struct dentry *regmap_debugfs_root;
25static LIST_HEAD(regmap_debugfs_early_list);
26static DEFINE_MUTEX(regmap_debugfs_early_lock);
27
28/* Calculate the length of a fixed format */
29static size_t regmap_calc_reg_len(int max_val)
30{
31 return snprintf(NULL, 0, "%x", max_val);
32}
33
34static ssize_t regmap_name_read_file(struct file *file,
35 char __user *user_buf, size_t count,
36 loff_t *ppos)
37{
38 struct regmap *map = file->private_data;
39 const char *name = "nodev";
40 int ret;
41 char *buf;
42
43 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
44 if (!buf)
45 return -ENOMEM;
46
47 if (map->dev && map->dev->driver)
48 name = map->dev->driver->name;
49
50 ret = snprintf(buf, PAGE_SIZE, "%s\n", name);
51 if (ret >= PAGE_SIZE) {
52 kfree(buf);
53 return ret;
54 }
55
56 ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
57 kfree(buf);
58 return ret;
59}
60
61static const struct file_operations regmap_name_fops = {
62 .open = simple_open,
63 .read = regmap_name_read_file,
64 .llseek = default_llseek,
65};
66
67static void regmap_debugfs_free_dump_cache(struct regmap *map)
68{
69 struct regmap_debugfs_off_cache *c;
70
71 while (!list_empty(&map->debugfs_off_cache)) {
72 c = list_first_entry(&map->debugfs_off_cache,
73 struct regmap_debugfs_off_cache,
74 list);
75 list_del(&c->list);
76 kfree(c);
77 }
78}
79
80static bool regmap_printable(struct regmap *map, unsigned int reg)
81{
82 if (regmap_precious(map, reg))
83 return false;
84
85 if (!regmap_readable(map, reg) && !regmap_cached(map, reg))
86 return false;
87
88 return true;
89}
90
91/*
92 * Work out where the start offset maps into register numbers, bearing
93 * in mind that we suppress hidden registers.
94 */
95static unsigned int regmap_debugfs_get_dump_start(struct regmap *map,
96 unsigned int base,
97 loff_t from,
98 loff_t *pos)
99{
100 struct regmap_debugfs_off_cache *c = NULL;
101 loff_t p = 0;
102 unsigned int i, ret;
103 unsigned int fpos_offset;
104 unsigned int reg_offset;
105
106 /* Suppress the cache if we're using a subrange */
107 if (base)
108 return base;
109
110 /*
111 * If we don't have a cache build one so we don't have to do a
112 * linear scan each time.
113 */
114 mutex_lock(&map->cache_lock);
115 i = base;
116 if (list_empty(&map->debugfs_off_cache)) {
117 for (; i <= map->max_register; i += map->reg_stride) {
118 /* Skip unprinted registers, closing off cache entry */
119 if (!regmap_printable(map, i)) {
120 if (c) {
121 c->max = p - 1;
122 c->max_reg = i - map->reg_stride;
123 list_add_tail(&c->list,
124 &map->debugfs_off_cache);
125 c = NULL;
126 }
127
128 continue;
129 }
130
131 /* No cache entry? Start a new one */
132 if (!c) {
133 c = kzalloc(sizeof(*c), GFP_KERNEL);
134 if (!c) {
135 regmap_debugfs_free_dump_cache(map);
136 mutex_unlock(&map->cache_lock);
137 return base;
138 }
139 c->min = p;
140 c->base_reg = i;
141 }
142
143 p += map->debugfs_tot_len;
144 }
145 }
146
147 /* Close the last entry off if we didn't scan beyond it */
148 if (c) {
149 c->max = p - 1;
150 c->max_reg = i - map->reg_stride;
151 list_add_tail(&c->list,
152 &map->debugfs_off_cache);
153 }
154
155 /*
156 * This should never happen; we return above if we fail to
157 * allocate and we should never be in this code if there are
158 * no registers at all.
159 */
160 WARN_ON(list_empty(&map->debugfs_off_cache));
161 ret = base;
162
163 /* Find the relevant block:offset */
164 list_for_each_entry(c, &map->debugfs_off_cache, list) {
165 if (from >= c->min && from <= c->max) {
166 fpos_offset = from - c->min;
167 reg_offset = fpos_offset / map->debugfs_tot_len;
168 *pos = c->min + (reg_offset * map->debugfs_tot_len);
169 mutex_unlock(&map->cache_lock);
170 return c->base_reg + (reg_offset * map->reg_stride);
171 }
172
173 *pos = c->max;
174 ret = c->max_reg;
175 }
176 mutex_unlock(&map->cache_lock);
177
178 return ret;
179}
180
181static inline void regmap_calc_tot_len(struct regmap *map,
182 void *buf, size_t count)
183{
184 /* Calculate the length of a fixed format */
185 if (!map->debugfs_tot_len) {
186 map->debugfs_reg_len = regmap_calc_reg_len(map->max_register);
187 map->debugfs_val_len = 2 * map->format.val_bytes;
188 map->debugfs_tot_len = map->debugfs_reg_len +
189 map->debugfs_val_len + 3; /* : \n */
190 }
191}
192
193static int regmap_next_readable_reg(struct regmap *map, int reg)
194{
195 struct regmap_debugfs_off_cache *c;
196 int ret = -EINVAL;
197
198 if (regmap_printable(map, reg + map->reg_stride)) {
199 ret = reg + map->reg_stride;
200 } else {
201 mutex_lock(&map->cache_lock);
202 list_for_each_entry(c, &map->debugfs_off_cache, list) {
203 if (reg > c->max_reg)
204 continue;
205 if (reg < c->base_reg) {
206 ret = c->base_reg;
207 break;
208 }
209 }
210 mutex_unlock(&map->cache_lock);
211 }
212 return ret;
213}
214
215static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
216 unsigned int to, char __user *user_buf,
217 size_t count, loff_t *ppos)
218{
219 size_t buf_pos = 0;
220 loff_t p = *ppos;
221 ssize_t ret;
222 int i;
223 char *buf;
224 unsigned int val, start_reg;
225
226 if (*ppos < 0 || !count)
227 return -EINVAL;
228
229 if (count > (PAGE_SIZE << MAX_PAGE_ORDER))
230 count = PAGE_SIZE << MAX_PAGE_ORDER;
231
232 buf = kmalloc(count, GFP_KERNEL);
233 if (!buf)
234 return -ENOMEM;
235
236 regmap_calc_tot_len(map, buf, count);
237
238 /* Work out which register we're starting at */
239 start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p);
240
241 for (i = start_reg; i >= 0 && i <= to;
242 i = regmap_next_readable_reg(map, i)) {
243
244 /* If we're in the region the user is trying to read */
245 if (p >= *ppos) {
246 /* ...but not beyond it */
247 if (buf_pos + map->debugfs_tot_len > count)
248 break;
249
250 /* Format the register */
251 snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
252 map->debugfs_reg_len, i - from);
253 buf_pos += map->debugfs_reg_len + 2;
254
255 /* Format the value, write all X if we can't read */
256 ret = regmap_read(map, i, &val);
257 if (ret == 0)
258 snprintf(buf + buf_pos, count - buf_pos,
259 "%.*x", map->debugfs_val_len, val);
260 else
261 memset(buf + buf_pos, 'X',
262 map->debugfs_val_len);
263 buf_pos += 2 * map->format.val_bytes;
264
265 buf[buf_pos++] = '\n';
266 }
267 p += map->debugfs_tot_len;
268 }
269
270 ret = buf_pos;
271
272 if (copy_to_user(user_buf, buf, buf_pos)) {
273 ret = -EFAULT;
274 goto out;
275 }
276
277 *ppos += buf_pos;
278
279out:
280 kfree(buf);
281 return ret;
282}
283
284static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
285 size_t count, loff_t *ppos)
286{
287 struct regmap *map = file->private_data;
288
289 return regmap_read_debugfs(map, 0, map->max_register, user_buf,
290 count, ppos);
291}
292
293#undef REGMAP_ALLOW_WRITE_DEBUGFS
294#ifdef REGMAP_ALLOW_WRITE_DEBUGFS
295/*
296 * This can be dangerous especially when we have clients such as
297 * PMICs, therefore don't provide any real compile time configuration option
298 * for this feature, people who want to use this will need to modify
299 * the source code directly.
300 */
301static ssize_t regmap_map_write_file(struct file *file,
302 const char __user *user_buf,
303 size_t count, loff_t *ppos)
304{
305 char buf[32];
306 size_t buf_size;
307 char *start = buf;
308 unsigned long reg, value;
309 struct regmap *map = file->private_data;
310 int ret;
311
312 buf_size = min(count, (sizeof(buf)-1));
313 if (copy_from_user(buf, user_buf, buf_size))
314 return -EFAULT;
315 buf[buf_size] = 0;
316
317 while (*start == ' ')
318 start++;
319 reg = simple_strtoul(start, &start, 16);
320 while (*start == ' ')
321 start++;
322 if (kstrtoul(start, 16, &value))
323 return -EINVAL;
324
325 /* Userspace has been fiddling around behind the kernel's back */
326 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
327
328 ret = regmap_write(map, reg, value);
329 if (ret < 0)
330 return ret;
331 return buf_size;
332}
333#else
334#define regmap_map_write_file NULL
335#endif
336
337static const struct file_operations regmap_map_fops = {
338 .open = simple_open,
339 .read = regmap_map_read_file,
340 .write = regmap_map_write_file,
341 .llseek = default_llseek,
342};
343
344static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf,
345 size_t count, loff_t *ppos)
346{
347 struct regmap_range_node *range = file->private_data;
348 struct regmap *map = range->map;
349
350 return regmap_read_debugfs(map, range->range_min, range->range_max,
351 user_buf, count, ppos);
352}
353
354static const struct file_operations regmap_range_fops = {
355 .open = simple_open,
356 .read = regmap_range_read_file,
357 .llseek = default_llseek,
358};
359
360static ssize_t regmap_reg_ranges_read_file(struct file *file,
361 char __user *user_buf, size_t count,
362 loff_t *ppos)
363{
364 struct regmap *map = file->private_data;
365 struct regmap_debugfs_off_cache *c;
366 loff_t p = 0;
367 size_t buf_pos = 0;
368 char *buf;
369 char *entry;
370 int ret;
371 unsigned int entry_len;
372
373 if (*ppos < 0 || !count)
374 return -EINVAL;
375
376 if (count > (PAGE_SIZE << MAX_PAGE_ORDER))
377 count = PAGE_SIZE << MAX_PAGE_ORDER;
378
379 buf = kmalloc(count, GFP_KERNEL);
380 if (!buf)
381 return -ENOMEM;
382
383 entry = kmalloc(PAGE_SIZE, GFP_KERNEL);
384 if (!entry) {
385 kfree(buf);
386 return -ENOMEM;
387 }
388
389 /* While we are at it, build the register dump cache
390 * now so the read() operation on the `registers' file
391 * can benefit from using the cache. We do not care
392 * about the file position information that is contained
393 * in the cache, just about the actual register blocks */
394 regmap_calc_tot_len(map, buf, count);
395 regmap_debugfs_get_dump_start(map, 0, *ppos, &p);
396
397 /* Reset file pointer as the fixed-format of the `registers'
398 * file is not compatible with the `range' file */
399 p = 0;
400 mutex_lock(&map->cache_lock);
401 list_for_each_entry(c, &map->debugfs_off_cache, list) {
402 entry_len = snprintf(entry, PAGE_SIZE, "%x-%x\n",
403 c->base_reg, c->max_reg);
404 if (p >= *ppos) {
405 if (buf_pos + entry_len > count)
406 break;
407 memcpy(buf + buf_pos, entry, entry_len);
408 buf_pos += entry_len;
409 }
410 p += entry_len;
411 }
412 mutex_unlock(&map->cache_lock);
413
414 kfree(entry);
415 ret = buf_pos;
416
417 if (copy_to_user(user_buf, buf, buf_pos)) {
418 ret = -EFAULT;
419 goto out_buf;
420 }
421
422 *ppos += buf_pos;
423out_buf:
424 kfree(buf);
425 return ret;
426}
427
428static const struct file_operations regmap_reg_ranges_fops = {
429 .open = simple_open,
430 .read = regmap_reg_ranges_read_file,
431 .llseek = default_llseek,
432};
433
434static int regmap_access_show(struct seq_file *s, void *ignored)
435{
436 struct regmap *map = s->private;
437 int i, reg_len;
438
439 reg_len = regmap_calc_reg_len(map->max_register);
440
441 for (i = 0; i <= map->max_register; i += map->reg_stride) {
442 /* Ignore registers which are neither readable nor writable */
443 if (!regmap_readable(map, i) && !regmap_writeable(map, i))
444 continue;
445
446 /* Format the register */
447 seq_printf(s, "%.*x: %c %c %c %c\n", reg_len, i,
448 regmap_readable(map, i) ? 'y' : 'n',
449 regmap_writeable(map, i) ? 'y' : 'n',
450 regmap_volatile(map, i) ? 'y' : 'n',
451 regmap_precious(map, i) ? 'y' : 'n');
452 }
453
454 return 0;
455}
456
457DEFINE_SHOW_ATTRIBUTE(regmap_access);
458
459static ssize_t regmap_cache_only_write_file(struct file *file,
460 const char __user *user_buf,
461 size_t count, loff_t *ppos)
462{
463 struct regmap *map = container_of(file->private_data,
464 struct regmap, cache_only);
465 bool new_val, require_sync = false;
466 int err;
467
468 err = kstrtobool_from_user(user_buf, count, &new_val);
469 /* Ignore malforned data like debugfs_write_file_bool() */
470 if (err)
471 return count;
472
473 err = debugfs_file_get(file->f_path.dentry);
474 if (err)
475 return err;
476
477 map->lock(map->lock_arg);
478
479 if (new_val && !map->cache_only) {
480 dev_warn(map->dev, "debugfs cache_only=Y forced\n");
481 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
482 } else if (!new_val && map->cache_only) {
483 dev_warn(map->dev, "debugfs cache_only=N forced: syncing cache\n");
484 require_sync = true;
485 }
486 map->cache_only = new_val;
487
488 map->unlock(map->lock_arg);
489 debugfs_file_put(file->f_path.dentry);
490
491 if (require_sync) {
492 err = regcache_sync(map);
493 if (err)
494 dev_err(map->dev, "Failed to sync cache %d\n", err);
495 }
496
497 return count;
498}
499
500static const struct file_operations regmap_cache_only_fops = {
501 .open = simple_open,
502 .read = debugfs_read_file_bool,
503 .write = regmap_cache_only_write_file,
504};
505
506static ssize_t regmap_cache_bypass_write_file(struct file *file,
507 const char __user *user_buf,
508 size_t count, loff_t *ppos)
509{
510 struct regmap *map = container_of(file->private_data,
511 struct regmap, cache_bypass);
512 bool new_val;
513 int err;
514
515 err = kstrtobool_from_user(user_buf, count, &new_val);
516 /* Ignore malforned data like debugfs_write_file_bool() */
517 if (err)
518 return count;
519
520 err = debugfs_file_get(file->f_path.dentry);
521 if (err)
522 return err;
523
524 map->lock(map->lock_arg);
525
526 if (new_val && !map->cache_bypass) {
527 dev_warn(map->dev, "debugfs cache_bypass=Y forced\n");
528 add_taint(TAINT_USER, LOCKDEP_STILL_OK);
529 } else if (!new_val && map->cache_bypass) {
530 dev_warn(map->dev, "debugfs cache_bypass=N forced\n");
531 }
532 map->cache_bypass = new_val;
533
534 map->unlock(map->lock_arg);
535 debugfs_file_put(file->f_path.dentry);
536
537 return count;
538}
539
540static const struct file_operations regmap_cache_bypass_fops = {
541 .open = simple_open,
542 .read = debugfs_read_file_bool,
543 .write = regmap_cache_bypass_write_file,
544};
545
546void regmap_debugfs_init(struct regmap *map)
547{
548 struct rb_node *next;
549 struct regmap_range_node *range_node;
550 const char *devname = "dummy";
551 const char *name = map->name;
552
553 /*
554 * Userspace can initiate reads from the hardware over debugfs.
555 * Normally internal regmap structures and buffers are protected with
556 * a mutex or a spinlock, but if the regmap owner decided to disable
557 * all locking mechanisms, this is no longer the case. For safety:
558 * don't create the debugfs entries if locking is disabled.
559 */
560 if (map->debugfs_disable) {
561 dev_dbg(map->dev, "regmap locking disabled - not creating debugfs entries\n");
562 return;
563 }
564
565 /* If we don't have the debugfs root yet, postpone init */
566 if (!regmap_debugfs_root) {
567 struct regmap_debugfs_node *node;
568 node = kzalloc(sizeof(*node), GFP_KERNEL);
569 if (!node)
570 return;
571 node->map = map;
572 mutex_lock(®map_debugfs_early_lock);
573 list_add(&node->link, ®map_debugfs_early_list);
574 mutex_unlock(®map_debugfs_early_lock);
575 return;
576 }
577
578 INIT_LIST_HEAD(&map->debugfs_off_cache);
579 mutex_init(&map->cache_lock);
580
581 if (map->dev)
582 devname = dev_name(map->dev);
583
584 if (name) {
585 if (!map->debugfs_name) {
586 map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
587 devname, name);
588 if (!map->debugfs_name)
589 return;
590 }
591 name = map->debugfs_name;
592 } else {
593 name = devname;
594 }
595
596 if (!strcmp(name, "dummy")) {
597 kfree(map->debugfs_name);
598 map->debugfs_name = kasprintf(GFP_KERNEL, "dummy%d",
599 dummy_index);
600 if (!map->debugfs_name)
601 return;
602 name = map->debugfs_name;
603 dummy_index++;
604 }
605
606 map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
607
608 debugfs_create_file("name", 0400, map->debugfs,
609 map, ®map_name_fops);
610
611 debugfs_create_file("range", 0400, map->debugfs,
612 map, ®map_reg_ranges_fops);
613
614 if (map->max_register || regmap_readable(map, 0)) {
615 umode_t registers_mode;
616
617#if defined(REGMAP_ALLOW_WRITE_DEBUGFS)
618 registers_mode = 0600;
619#else
620 registers_mode = 0400;
621#endif
622
623 debugfs_create_file("registers", registers_mode, map->debugfs,
624 map, ®map_map_fops);
625 debugfs_create_file("access", 0400, map->debugfs,
626 map, ®map_access_fops);
627 }
628
629 if (map->cache_type) {
630 debugfs_create_file("cache_only", 0600, map->debugfs,
631 &map->cache_only, ®map_cache_only_fops);
632 debugfs_create_bool("cache_dirty", 0400, map->debugfs,
633 &map->cache_dirty);
634 debugfs_create_file("cache_bypass", 0600, map->debugfs,
635 &map->cache_bypass,
636 ®map_cache_bypass_fops);
637 }
638
639 /*
640 * This could interfere with driver operation. Therefore, don't provide
641 * any real compile time configuration option for this feature. One will
642 * have to modify the source code directly in order to use it.
643 */
644#undef REGMAP_ALLOW_FORCE_WRITE_FIELD_DEBUGFS
645#ifdef REGMAP_ALLOW_FORCE_WRITE_FIELD_DEBUGFS
646 debugfs_create_bool("force_write_field", 0600, map->debugfs,
647 &map->force_write_field);
648#endif
649
650 next = rb_first(&map->range_tree);
651 while (next) {
652 range_node = rb_entry(next, struct regmap_range_node, node);
653
654 if (range_node->name)
655 debugfs_create_file(range_node->name, 0400,
656 map->debugfs, range_node,
657 ®map_range_fops);
658
659 next = rb_next(&range_node->node);
660 }
661
662 if (map->cache_ops && map->cache_ops->debugfs_init)
663 map->cache_ops->debugfs_init(map);
664}
665
666void regmap_debugfs_exit(struct regmap *map)
667{
668 if (map->debugfs) {
669 debugfs_remove_recursive(map->debugfs);
670 mutex_lock(&map->cache_lock);
671 regmap_debugfs_free_dump_cache(map);
672 mutex_unlock(&map->cache_lock);
673 kfree(map->debugfs_name);
674 map->debugfs_name = NULL;
675 } else {
676 struct regmap_debugfs_node *node, *tmp;
677
678 mutex_lock(®map_debugfs_early_lock);
679 list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list,
680 link) {
681 if (node->map == map) {
682 list_del(&node->link);
683 kfree(node);
684 }
685 }
686 mutex_unlock(®map_debugfs_early_lock);
687 }
688}
689
690void regmap_debugfs_initcall(void)
691{
692 struct regmap_debugfs_node *node, *tmp;
693
694 regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
695
696 mutex_lock(®map_debugfs_early_lock);
697 list_for_each_entry_safe(node, tmp, ®map_debugfs_early_list, link) {
698 regmap_debugfs_init(node->map);
699 list_del(&node->link);
700 kfree(node);
701 }
702 mutex_unlock(®map_debugfs_early_lock);
703}
1/*
2 * Register map access API - debugfs
3 *
4 * Copyright 2011 Wolfson Microelectronics plc
5 *
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 as
10 * published by the Free Software Foundation.
11 */
12
13#include <linux/slab.h>
14#include <linux/mutex.h>
15#include <linux/debugfs.h>
16#include <linux/uaccess.h>
17#include <linux/device.h>
18
19#include "internal.h"
20
21static struct dentry *regmap_debugfs_root;
22
23/* Calculate the length of a fixed format */
24static size_t regmap_calc_reg_len(int max_val, char *buf, size_t buf_size)
25{
26 snprintf(buf, buf_size, "%x", max_val);
27 return strlen(buf);
28}
29
30static ssize_t regmap_name_read_file(struct file *file,
31 char __user *user_buf, size_t count,
32 loff_t *ppos)
33{
34 struct regmap *map = file->private_data;
35 int ret;
36 char *buf;
37
38 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
39 if (!buf)
40 return -ENOMEM;
41
42 ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name);
43 if (ret < 0) {
44 kfree(buf);
45 return ret;
46 }
47
48 ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
49 kfree(buf);
50 return ret;
51}
52
53static const struct file_operations regmap_name_fops = {
54 .open = simple_open,
55 .read = regmap_name_read_file,
56 .llseek = default_llseek,
57};
58
59static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
60 size_t count, loff_t *ppos)
61{
62 int reg_len, val_len, tot_len;
63 size_t buf_pos = 0;
64 loff_t p = 0;
65 ssize_t ret;
66 int i;
67 struct regmap *map = file->private_data;
68 char *buf;
69 unsigned int val;
70
71 if (*ppos < 0 || !count)
72 return -EINVAL;
73
74 buf = kmalloc(count, GFP_KERNEL);
75 if (!buf)
76 return -ENOMEM;
77
78 /* Calculate the length of a fixed format */
79 reg_len = regmap_calc_reg_len(map->max_register, buf, count);
80 val_len = 2 * map->format.val_bytes;
81 tot_len = reg_len + val_len + 3; /* : \n */
82
83 for (i = 0; i <= map->max_register; i += map->reg_stride) {
84 if (!regmap_readable(map, i))
85 continue;
86
87 if (regmap_precious(map, i))
88 continue;
89
90 /* If we're in the region the user is trying to read */
91 if (p >= *ppos) {
92 /* ...but not beyond it */
93 if (buf_pos >= count - 1 - tot_len)
94 break;
95
96 /* Format the register */
97 snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
98 reg_len, i);
99 buf_pos += reg_len + 2;
100
101 /* Format the value, write all X if we can't read */
102 ret = regmap_read(map, i, &val);
103 if (ret == 0)
104 snprintf(buf + buf_pos, count - buf_pos,
105 "%.*x", val_len, val);
106 else
107 memset(buf + buf_pos, 'X', val_len);
108 buf_pos += 2 * map->format.val_bytes;
109
110 buf[buf_pos++] = '\n';
111 }
112 p += tot_len;
113 }
114
115 ret = buf_pos;
116
117 if (copy_to_user(user_buf, buf, buf_pos)) {
118 ret = -EFAULT;
119 goto out;
120 }
121
122 *ppos += buf_pos;
123
124out:
125 kfree(buf);
126 return ret;
127}
128
129#undef REGMAP_ALLOW_WRITE_DEBUGFS
130#ifdef REGMAP_ALLOW_WRITE_DEBUGFS
131/*
132 * This can be dangerous especially when we have clients such as
133 * PMICs, therefore don't provide any real compile time configuration option
134 * for this feature, people who want to use this will need to modify
135 * the source code directly.
136 */
137static ssize_t regmap_map_write_file(struct file *file,
138 const char __user *user_buf,
139 size_t count, loff_t *ppos)
140{
141 char buf[32];
142 size_t buf_size;
143 char *start = buf;
144 unsigned long reg, value;
145 struct regmap *map = file->private_data;
146
147 buf_size = min(count, (sizeof(buf)-1));
148 if (copy_from_user(buf, user_buf, buf_size))
149 return -EFAULT;
150 buf[buf_size] = 0;
151
152 while (*start == ' ')
153 start++;
154 reg = simple_strtoul(start, &start, 16);
155 while (*start == ' ')
156 start++;
157 if (strict_strtoul(start, 16, &value))
158 return -EINVAL;
159
160 /* Userspace has been fiddling around behind the kernel's back */
161 add_taint(TAINT_USER);
162
163 regmap_write(map, reg, value);
164 return buf_size;
165}
166#else
167#define regmap_map_write_file NULL
168#endif
169
170static const struct file_operations regmap_map_fops = {
171 .open = simple_open,
172 .read = regmap_map_read_file,
173 .write = regmap_map_write_file,
174 .llseek = default_llseek,
175};
176
177static ssize_t regmap_access_read_file(struct file *file,
178 char __user *user_buf, size_t count,
179 loff_t *ppos)
180{
181 int reg_len, tot_len;
182 size_t buf_pos = 0;
183 loff_t p = 0;
184 ssize_t ret;
185 int i;
186 struct regmap *map = file->private_data;
187 char *buf;
188
189 if (*ppos < 0 || !count)
190 return -EINVAL;
191
192 buf = kmalloc(count, GFP_KERNEL);
193 if (!buf)
194 return -ENOMEM;
195
196 /* Calculate the length of a fixed format */
197 reg_len = regmap_calc_reg_len(map->max_register, buf, count);
198 tot_len = reg_len + 10; /* ': R W V P\n' */
199
200 for (i = 0; i <= map->max_register; i += map->reg_stride) {
201 /* Ignore registers which are neither readable nor writable */
202 if (!regmap_readable(map, i) && !regmap_writeable(map, i))
203 continue;
204
205 /* If we're in the region the user is trying to read */
206 if (p >= *ppos) {
207 /* ...but not beyond it */
208 if (buf_pos >= count - 1 - tot_len)
209 break;
210
211 /* Format the register */
212 snprintf(buf + buf_pos, count - buf_pos,
213 "%.*x: %c %c %c %c\n",
214 reg_len, i,
215 regmap_readable(map, i) ? 'y' : 'n',
216 regmap_writeable(map, i) ? 'y' : 'n',
217 regmap_volatile(map, i) ? 'y' : 'n',
218 regmap_precious(map, i) ? 'y' : 'n');
219
220 buf_pos += tot_len;
221 }
222 p += tot_len;
223 }
224
225 ret = buf_pos;
226
227 if (copy_to_user(user_buf, buf, buf_pos)) {
228 ret = -EFAULT;
229 goto out;
230 }
231
232 *ppos += buf_pos;
233
234out:
235 kfree(buf);
236 return ret;
237}
238
239static const struct file_operations regmap_access_fops = {
240 .open = simple_open,
241 .read = regmap_access_read_file,
242 .llseek = default_llseek,
243};
244
245void regmap_debugfs_init(struct regmap *map, const char *name)
246{
247 if (name) {
248 map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
249 dev_name(map->dev), name);
250 name = map->debugfs_name;
251 } else {
252 name = dev_name(map->dev);
253 }
254
255 map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
256 if (!map->debugfs) {
257 dev_warn(map->dev, "Failed to create debugfs directory\n");
258 return;
259 }
260
261 debugfs_create_file("name", 0400, map->debugfs,
262 map, ®map_name_fops);
263
264 if (map->max_register) {
265 debugfs_create_file("registers", 0400, map->debugfs,
266 map, ®map_map_fops);
267 debugfs_create_file("access", 0400, map->debugfs,
268 map, ®map_access_fops);
269 }
270
271 if (map->cache_type) {
272 debugfs_create_bool("cache_only", 0400, map->debugfs,
273 &map->cache_only);
274 debugfs_create_bool("cache_dirty", 0400, map->debugfs,
275 &map->cache_dirty);
276 debugfs_create_bool("cache_bypass", 0400, map->debugfs,
277 &map->cache_bypass);
278 }
279}
280
281void regmap_debugfs_exit(struct regmap *map)
282{
283 debugfs_remove_recursive(map->debugfs);
284 kfree(map->debugfs_name);
285}
286
287void regmap_debugfs_initcall(void)
288{
289 regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
290 if (!regmap_debugfs_root) {
291 pr_warn("regmap: Failed to create debugfs root\n");
292 return;
293 }
294}