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