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