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31244e39 MB |
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> | |
31244e39 MB |
14 | #include <linux/mutex.h> |
15 | #include <linux/debugfs.h> | |
16 | #include <linux/uaccess.h> | |
51990e82 | 17 | #include <linux/device.h> |
31244e39 MB |
18 | |
19 | #include "internal.h" | |
20 | ||
21 | static struct dentry *regmap_debugfs_root; | |
22 | ||
21f55544 MB |
23 | /* Calculate the length of a fixed format */ |
24 | static 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 | ||
f0c2319f DP |
30 | static 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 | ||
53 | static const struct file_operations regmap_name_fops = { | |
234e3405 | 54 | .open = simple_open, |
f0c2319f DP |
55 | .read = regmap_name_read_file, |
56 | .llseek = default_llseek, | |
57 | }; | |
58 | ||
95f971c7 MB |
59 | static void regmap_debugfs_free_dump_cache(struct regmap *map) |
60 | { | |
61 | struct regmap_debugfs_off_cache *c; | |
62 | ||
63 | while (!list_empty(&map->debugfs_off_cache)) { | |
64 | c = list_first_entry(&map->debugfs_off_cache, | |
65 | struct regmap_debugfs_off_cache, | |
66 | list); | |
67 | list_del(&c->list); | |
68 | kfree(c); | |
69 | } | |
70 | } | |
71 | ||
afab2f7b MB |
72 | /* |
73 | * Work out where the start offset maps into register numbers, bearing | |
74 | * in mind that we suppress hidden registers. | |
75 | */ | |
76 | static unsigned int regmap_debugfs_get_dump_start(struct regmap *map, | |
77 | unsigned int base, | |
78 | loff_t from, | |
79 | loff_t *pos) | |
80 | { | |
5166b7c0 MB |
81 | struct regmap_debugfs_off_cache *c = NULL; |
82 | loff_t p = 0; | |
83 | unsigned int i, ret; | |
c2c1ee66 DP |
84 | unsigned int fpos_offset; |
85 | unsigned int reg_offset; | |
5166b7c0 | 86 | |
d6814a7d | 87 | /* Suppress the cache if we're using a subrange */ |
26ee4741 LPC |
88 | if (base) |
89 | return base; | |
d6814a7d | 90 | |
5166b7c0 MB |
91 | /* |
92 | * If we don't have a cache build one so we don't have to do a | |
93 | * linear scan each time. | |
94 | */ | |
065b4c58 | 95 | mutex_lock(&map->cache_lock); |
480738de | 96 | i = base; |
5166b7c0 | 97 | if (list_empty(&map->debugfs_off_cache)) { |
480738de | 98 | for (; i <= map->max_register; i += map->reg_stride) { |
5166b7c0 MB |
99 | /* Skip unprinted registers, closing off cache entry */ |
100 | if (!regmap_readable(map, i) || | |
101 | regmap_precious(map, i)) { | |
102 | if (c) { | |
103 | c->max = p - 1; | |
480738de | 104 | c->max_reg = i - map->reg_stride; |
5166b7c0 MB |
105 | list_add_tail(&c->list, |
106 | &map->debugfs_off_cache); | |
107 | c = NULL; | |
108 | } | |
109 | ||
110 | continue; | |
111 | } | |
112 | ||
113 | /* No cache entry? Start a new one */ | |
114 | if (!c) { | |
115 | c = kzalloc(sizeof(*c), GFP_KERNEL); | |
95f971c7 MB |
116 | if (!c) { |
117 | regmap_debugfs_free_dump_cache(map); | |
065b4c58 | 118 | mutex_unlock(&map->cache_lock); |
95f971c7 MB |
119 | return base; |
120 | } | |
5166b7c0 MB |
121 | c->min = p; |
122 | c->base_reg = i; | |
123 | } | |
124 | ||
125 | p += map->debugfs_tot_len; | |
126 | } | |
127 | } | |
afab2f7b | 128 | |
e8d6539c MB |
129 | /* Close the last entry off if we didn't scan beyond it */ |
130 | if (c) { | |
131 | c->max = p - 1; | |
480738de | 132 | c->max_reg = i - map->reg_stride; |
e8d6539c MB |
133 | list_add_tail(&c->list, |
134 | &map->debugfs_off_cache); | |
e8d6539c MB |
135 | } |
136 | ||
5bd9f4bb MB |
137 | /* |
138 | * This should never happen; we return above if we fail to | |
139 | * allocate and we should never be in this code if there are | |
140 | * no registers at all. | |
141 | */ | |
a3471469 RK |
142 | WARN_ON(list_empty(&map->debugfs_off_cache)); |
143 | ret = base; | |
5bd9f4bb | 144 | |
cf57d607 | 145 | /* Find the relevant block:offset */ |
5166b7c0 | 146 | list_for_each_entry(c, &map->debugfs_off_cache, list) { |
5a1d6d17 | 147 | if (from >= c->min && from <= c->max) { |
cf57d607 DP |
148 | fpos_offset = from - c->min; |
149 | reg_offset = fpos_offset / map->debugfs_tot_len; | |
150 | *pos = c->min + (reg_offset * map->debugfs_tot_len); | |
065b4c58 | 151 | mutex_unlock(&map->cache_lock); |
213fa5d9 | 152 | return c->base_reg + (reg_offset * map->reg_stride); |
afab2f7b MB |
153 | } |
154 | ||
cf57d607 DP |
155 | *pos = c->max; |
156 | ret = c->max_reg; | |
afab2f7b | 157 | } |
065b4c58 | 158 | mutex_unlock(&map->cache_lock); |
afab2f7b | 159 | |
5166b7c0 | 160 | return ret; |
afab2f7b MB |
161 | } |
162 | ||
4dd7c553 DP |
163 | static inline void regmap_calc_tot_len(struct regmap *map, |
164 | void *buf, size_t count) | |
165 | { | |
166 | /* Calculate the length of a fixed format */ | |
167 | if (!map->debugfs_tot_len) { | |
168 | map->debugfs_reg_len = regmap_calc_reg_len(map->max_register, | |
169 | buf, count); | |
170 | map->debugfs_val_len = 2 * map->format.val_bytes; | |
171 | map->debugfs_tot_len = map->debugfs_reg_len + | |
172 | map->debugfs_val_len + 3; /* : \n */ | |
173 | } | |
174 | } | |
175 | ||
bd9cc12f MB |
176 | static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from, |
177 | unsigned int to, char __user *user_buf, | |
178 | size_t count, loff_t *ppos) | |
31244e39 | 179 | { |
31244e39 | 180 | size_t buf_pos = 0; |
afab2f7b | 181 | loff_t p = *ppos; |
31244e39 MB |
182 | ssize_t ret; |
183 | int i; | |
31244e39 | 184 | char *buf; |
afab2f7b | 185 | unsigned int val, start_reg; |
31244e39 MB |
186 | |
187 | if (*ppos < 0 || !count) | |
188 | return -EINVAL; | |
189 | ||
190 | buf = kmalloc(count, GFP_KERNEL); | |
191 | if (!buf) | |
192 | return -ENOMEM; | |
193 | ||
4dd7c553 | 194 | regmap_calc_tot_len(map, buf, count); |
31244e39 | 195 | |
afab2f7b MB |
196 | /* Work out which register we're starting at */ |
197 | start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p); | |
198 | ||
199 | for (i = start_reg; i <= to; i += map->reg_stride) { | |
8de2f081 | 200 | if (!regmap_readable(map, i)) |
31244e39 MB |
201 | continue; |
202 | ||
8de2f081 | 203 | if (regmap_precious(map, i)) |
2efe1642 MB |
204 | continue; |
205 | ||
31244e39 MB |
206 | /* If we're in the region the user is trying to read */ |
207 | if (p >= *ppos) { | |
208 | /* ...but not beyond it */ | |
f3eb8399 | 209 | if (buf_pos + map->debugfs_tot_len > count) |
31244e39 MB |
210 | break; |
211 | ||
212 | /* Format the register */ | |
213 | snprintf(buf + buf_pos, count - buf_pos, "%.*x: ", | |
cbc1938b MB |
214 | map->debugfs_reg_len, i - from); |
215 | buf_pos += map->debugfs_reg_len + 2; | |
31244e39 MB |
216 | |
217 | /* Format the value, write all X if we can't read */ | |
218 | ret = regmap_read(map, i, &val); | |
219 | if (ret == 0) | |
220 | snprintf(buf + buf_pos, count - buf_pos, | |
cbc1938b | 221 | "%.*x", map->debugfs_val_len, val); |
31244e39 | 222 | else |
cbc1938b MB |
223 | memset(buf + buf_pos, 'X', |
224 | map->debugfs_val_len); | |
31244e39 MB |
225 | buf_pos += 2 * map->format.val_bytes; |
226 | ||
227 | buf[buf_pos++] = '\n'; | |
228 | } | |
cbc1938b | 229 | p += map->debugfs_tot_len; |
31244e39 MB |
230 | } |
231 | ||
232 | ret = buf_pos; | |
233 | ||
234 | if (copy_to_user(user_buf, buf, buf_pos)) { | |
235 | ret = -EFAULT; | |
236 | goto out; | |
237 | } | |
238 | ||
239 | *ppos += buf_pos; | |
240 | ||
241 | out: | |
242 | kfree(buf); | |
243 | return ret; | |
244 | } | |
245 | ||
bd9cc12f MB |
246 | static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf, |
247 | size_t count, loff_t *ppos) | |
248 | { | |
249 | struct regmap *map = file->private_data; | |
250 | ||
251 | return regmap_read_debugfs(map, 0, map->max_register, user_buf, | |
252 | count, ppos); | |
253 | } | |
254 | ||
09c6ecd3 DP |
255 | #undef REGMAP_ALLOW_WRITE_DEBUGFS |
256 | #ifdef REGMAP_ALLOW_WRITE_DEBUGFS | |
257 | /* | |
258 | * This can be dangerous especially when we have clients such as | |
259 | * PMICs, therefore don't provide any real compile time configuration option | |
260 | * for this feature, people who want to use this will need to modify | |
261 | * the source code directly. | |
262 | */ | |
263 | static ssize_t regmap_map_write_file(struct file *file, | |
264 | const char __user *user_buf, | |
265 | size_t count, loff_t *ppos) | |
266 | { | |
267 | char buf[32]; | |
268 | size_t buf_size; | |
269 | char *start = buf; | |
270 | unsigned long reg, value; | |
271 | struct regmap *map = file->private_data; | |
68e850d8 | 272 | int ret; |
09c6ecd3 DP |
273 | |
274 | buf_size = min(count, (sizeof(buf)-1)); | |
275 | if (copy_from_user(buf, user_buf, buf_size)) | |
276 | return -EFAULT; | |
277 | buf[buf_size] = 0; | |
278 | ||
279 | while (*start == ' ') | |
280 | start++; | |
281 | reg = simple_strtoul(start, &start, 16); | |
282 | while (*start == ' ') | |
283 | start++; | |
34da5e67 | 284 | if (kstrtoul(start, 16, &value)) |
09c6ecd3 DP |
285 | return -EINVAL; |
286 | ||
287 | /* Userspace has been fiddling around behind the kernel's back */ | |
f9e464a5 | 288 | add_taint(TAINT_USER, LOCKDEP_STILL_OK); |
09c6ecd3 | 289 | |
68e850d8 DP |
290 | ret = regmap_write(map, reg, value); |
291 | if (ret < 0) | |
292 | return ret; | |
09c6ecd3 DP |
293 | return buf_size; |
294 | } | |
295 | #else | |
296 | #define regmap_map_write_file NULL | |
297 | #endif | |
298 | ||
31244e39 | 299 | static const struct file_operations regmap_map_fops = { |
234e3405 | 300 | .open = simple_open, |
31244e39 | 301 | .read = regmap_map_read_file, |
09c6ecd3 | 302 | .write = regmap_map_write_file, |
31244e39 MB |
303 | .llseek = default_llseek, |
304 | }; | |
305 | ||
4b020b3f MB |
306 | static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf, |
307 | size_t count, loff_t *ppos) | |
308 | { | |
309 | struct regmap_range_node *range = file->private_data; | |
310 | struct regmap *map = range->map; | |
311 | ||
312 | return regmap_read_debugfs(map, range->range_min, range->range_max, | |
313 | user_buf, count, ppos); | |
314 | } | |
315 | ||
316 | static const struct file_operations regmap_range_fops = { | |
317 | .open = simple_open, | |
318 | .read = regmap_range_read_file, | |
319 | .llseek = default_llseek, | |
320 | }; | |
321 | ||
065b4c58 DP |
322 | static ssize_t regmap_reg_ranges_read_file(struct file *file, |
323 | char __user *user_buf, size_t count, | |
324 | loff_t *ppos) | |
325 | { | |
326 | struct regmap *map = file->private_data; | |
327 | struct regmap_debugfs_off_cache *c; | |
328 | loff_t p = 0; | |
329 | size_t buf_pos = 0; | |
330 | char *buf; | |
331 | char *entry; | |
332 | int ret; | |
333 | ||
334 | if (*ppos < 0 || !count) | |
335 | return -EINVAL; | |
336 | ||
337 | buf = kmalloc(count, GFP_KERNEL); | |
338 | if (!buf) | |
339 | return -ENOMEM; | |
340 | ||
341 | entry = kmalloc(PAGE_SIZE, GFP_KERNEL); | |
342 | if (!entry) { | |
343 | kfree(buf); | |
344 | return -ENOMEM; | |
345 | } | |
346 | ||
347 | /* While we are at it, build the register dump cache | |
348 | * now so the read() operation on the `registers' file | |
349 | * can benefit from using the cache. We do not care | |
350 | * about the file position information that is contained | |
351 | * in the cache, just about the actual register blocks */ | |
352 | regmap_calc_tot_len(map, buf, count); | |
353 | regmap_debugfs_get_dump_start(map, 0, *ppos, &p); | |
354 | ||
355 | /* Reset file pointer as the fixed-format of the `registers' | |
356 | * file is not compatible with the `range' file */ | |
357 | p = 0; | |
358 | mutex_lock(&map->cache_lock); | |
359 | list_for_each_entry(c, &map->debugfs_off_cache, list) { | |
360 | snprintf(entry, PAGE_SIZE, "%x-%x", | |
361 | c->base_reg, c->max_reg); | |
362 | if (p >= *ppos) { | |
363 | if (buf_pos + 1 + strlen(entry) > count) | |
364 | break; | |
365 | snprintf(buf + buf_pos, count - buf_pos, | |
366 | "%s", entry); | |
367 | buf_pos += strlen(entry); | |
368 | buf[buf_pos] = '\n'; | |
369 | buf_pos++; | |
370 | } | |
371 | p += strlen(entry) + 1; | |
372 | } | |
373 | mutex_unlock(&map->cache_lock); | |
374 | ||
375 | kfree(entry); | |
376 | ret = buf_pos; | |
377 | ||
378 | if (copy_to_user(user_buf, buf, buf_pos)) { | |
379 | ret = -EFAULT; | |
380 | goto out_buf; | |
381 | } | |
382 | ||
383 | *ppos += buf_pos; | |
384 | out_buf: | |
385 | kfree(buf); | |
386 | return ret; | |
387 | } | |
388 | ||
389 | static const struct file_operations regmap_reg_ranges_fops = { | |
390 | .open = simple_open, | |
391 | .read = regmap_reg_ranges_read_file, | |
392 | .llseek = default_llseek, | |
393 | }; | |
394 | ||
449e3842 MB |
395 | static ssize_t regmap_access_read_file(struct file *file, |
396 | char __user *user_buf, size_t count, | |
397 | loff_t *ppos) | |
398 | { | |
399 | int reg_len, tot_len; | |
400 | size_t buf_pos = 0; | |
401 | loff_t p = 0; | |
402 | ssize_t ret; | |
403 | int i; | |
404 | struct regmap *map = file->private_data; | |
405 | char *buf; | |
406 | ||
407 | if (*ppos < 0 || !count) | |
408 | return -EINVAL; | |
409 | ||
410 | buf = kmalloc(count, GFP_KERNEL); | |
411 | if (!buf) | |
412 | return -ENOMEM; | |
413 | ||
414 | /* Calculate the length of a fixed format */ | |
415 | reg_len = regmap_calc_reg_len(map->max_register, buf, count); | |
416 | tot_len = reg_len + 10; /* ': R W V P\n' */ | |
417 | ||
f01ee60f | 418 | for (i = 0; i <= map->max_register; i += map->reg_stride) { |
449e3842 MB |
419 | /* Ignore registers which are neither readable nor writable */ |
420 | if (!regmap_readable(map, i) && !regmap_writeable(map, i)) | |
421 | continue; | |
422 | ||
423 | /* If we're in the region the user is trying to read */ | |
424 | if (p >= *ppos) { | |
425 | /* ...but not beyond it */ | |
426 | if (buf_pos >= count - 1 - tot_len) | |
427 | break; | |
428 | ||
429 | /* Format the register */ | |
430 | snprintf(buf + buf_pos, count - buf_pos, | |
431 | "%.*x: %c %c %c %c\n", | |
432 | reg_len, i, | |
433 | regmap_readable(map, i) ? 'y' : 'n', | |
434 | regmap_writeable(map, i) ? 'y' : 'n', | |
435 | regmap_volatile(map, i) ? 'y' : 'n', | |
436 | regmap_precious(map, i) ? 'y' : 'n'); | |
437 | ||
438 | buf_pos += tot_len; | |
439 | } | |
440 | p += tot_len; | |
441 | } | |
442 | ||
443 | ret = buf_pos; | |
444 | ||
445 | if (copy_to_user(user_buf, buf, buf_pos)) { | |
446 | ret = -EFAULT; | |
447 | goto out; | |
448 | } | |
449 | ||
450 | *ppos += buf_pos; | |
451 | ||
452 | out: | |
453 | kfree(buf); | |
454 | return ret; | |
455 | } | |
456 | ||
457 | static const struct file_operations regmap_access_fops = { | |
234e3405 | 458 | .open = simple_open, |
449e3842 MB |
459 | .read = regmap_access_read_file, |
460 | .llseek = default_llseek, | |
461 | }; | |
31244e39 | 462 | |
d3c242e1 | 463 | void regmap_debugfs_init(struct regmap *map, const char *name) |
31244e39 | 464 | { |
4b020b3f MB |
465 | struct rb_node *next; |
466 | struct regmap_range_node *range_node; | |
467 | ||
5166b7c0 | 468 | INIT_LIST_HEAD(&map->debugfs_off_cache); |
065b4c58 | 469 | mutex_init(&map->cache_lock); |
5166b7c0 | 470 | |
d3c242e1 SW |
471 | if (name) { |
472 | map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s", | |
473 | dev_name(map->dev), name); | |
474 | name = map->debugfs_name; | |
475 | } else { | |
476 | name = dev_name(map->dev); | |
477 | } | |
478 | ||
479 | map->debugfs = debugfs_create_dir(name, regmap_debugfs_root); | |
31244e39 MB |
480 | if (!map->debugfs) { |
481 | dev_warn(map->dev, "Failed to create debugfs directory\n"); | |
482 | return; | |
483 | } | |
484 | ||
f0c2319f DP |
485 | debugfs_create_file("name", 0400, map->debugfs, |
486 | map, ®map_name_fops); | |
487 | ||
065b4c58 DP |
488 | debugfs_create_file("range", 0400, map->debugfs, |
489 | map, ®map_reg_ranges_fops); | |
490 | ||
449e3842 | 491 | if (map->max_register) { |
31244e39 MB |
492 | debugfs_create_file("registers", 0400, map->debugfs, |
493 | map, ®map_map_fops); | |
449e3842 MB |
494 | debugfs_create_file("access", 0400, map->debugfs, |
495 | map, ®map_access_fops); | |
496 | } | |
028a01e6 MB |
497 | |
498 | if (map->cache_type) { | |
499 | debugfs_create_bool("cache_only", 0400, map->debugfs, | |
500 | &map->cache_only); | |
501 | debugfs_create_bool("cache_dirty", 0400, map->debugfs, | |
502 | &map->cache_dirty); | |
503 | debugfs_create_bool("cache_bypass", 0400, map->debugfs, | |
504 | &map->cache_bypass); | |
505 | } | |
4b020b3f MB |
506 | |
507 | next = rb_first(&map->range_tree); | |
508 | while (next) { | |
509 | range_node = rb_entry(next, struct regmap_range_node, node); | |
510 | ||
511 | if (range_node->name) | |
512 | debugfs_create_file(range_node->name, 0400, | |
513 | map->debugfs, range_node, | |
514 | ®map_range_fops); | |
515 | ||
516 | next = rb_next(&range_node->node); | |
517 | } | |
31244e39 MB |
518 | } |
519 | ||
520 | void regmap_debugfs_exit(struct regmap *map) | |
521 | { | |
522 | debugfs_remove_recursive(map->debugfs); | |
065b4c58 | 523 | mutex_lock(&map->cache_lock); |
95f971c7 | 524 | regmap_debugfs_free_dump_cache(map); |
065b4c58 | 525 | mutex_unlock(&map->cache_lock); |
d3c242e1 | 526 | kfree(map->debugfs_name); |
31244e39 MB |
527 | } |
528 | ||
529 | void regmap_debugfs_initcall(void) | |
530 | { | |
531 | regmap_debugfs_root = debugfs_create_dir("regmap", NULL); | |
532 | if (!regmap_debugfs_root) { | |
533 | pr_warn("regmap: Failed to create debugfs root\n"); | |
534 | return; | |
535 | } | |
536 | } |