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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 MB |
86 | |
87 | /* | |
88 | * If we don't have a cache build one so we don't have to do a | |
89 | * linear scan each time. | |
90 | */ | |
91 | if (list_empty(&map->debugfs_off_cache)) { | |
92 | for (i = base; i <= map->max_register; i += map->reg_stride) { | |
93 | /* Skip unprinted registers, closing off cache entry */ | |
94 | if (!regmap_readable(map, i) || | |
95 | regmap_precious(map, i)) { | |
96 | if (c) { | |
97 | c->max = p - 1; | |
c2c1ee66 DP |
98 | fpos_offset = c->max - c->min; |
99 | reg_offset = fpos_offset / map->debugfs_tot_len; | |
100 | c->max_reg = c->base_reg + reg_offset; | |
5166b7c0 MB |
101 | list_add_tail(&c->list, |
102 | &map->debugfs_off_cache); | |
103 | c = NULL; | |
104 | } | |
105 | ||
106 | continue; | |
107 | } | |
108 | ||
109 | /* No cache entry? Start a new one */ | |
110 | if (!c) { | |
111 | c = kzalloc(sizeof(*c), GFP_KERNEL); | |
95f971c7 MB |
112 | if (!c) { |
113 | regmap_debugfs_free_dump_cache(map); | |
114 | return base; | |
115 | } | |
5166b7c0 MB |
116 | c->min = p; |
117 | c->base_reg = i; | |
118 | } | |
119 | ||
120 | p += map->debugfs_tot_len; | |
121 | } | |
122 | } | |
afab2f7b | 123 | |
e8d6539c MB |
124 | /* Close the last entry off if we didn't scan beyond it */ |
125 | if (c) { | |
126 | c->max = p - 1; | |
c2c1ee66 DP |
127 | fpos_offset = c->max - c->min; |
128 | reg_offset = fpos_offset / map->debugfs_tot_len; | |
129 | c->max_reg = c->base_reg + reg_offset; | |
e8d6539c MB |
130 | list_add_tail(&c->list, |
131 | &map->debugfs_off_cache); | |
e8d6539c MB |
132 | } |
133 | ||
5bd9f4bb MB |
134 | /* |
135 | * This should never happen; we return above if we fail to | |
136 | * allocate and we should never be in this code if there are | |
137 | * no registers at all. | |
138 | */ | |
a3471469 RK |
139 | WARN_ON(list_empty(&map->debugfs_off_cache)); |
140 | ret = base; | |
5bd9f4bb | 141 | |
cf57d607 | 142 | /* Find the relevant block:offset */ |
5166b7c0 | 143 | list_for_each_entry(c, &map->debugfs_off_cache, list) { |
5a1d6d17 | 144 | if (from >= c->min && from <= c->max) { |
cf57d607 DP |
145 | fpos_offset = from - c->min; |
146 | reg_offset = fpos_offset / map->debugfs_tot_len; | |
147 | *pos = c->min + (reg_offset * map->debugfs_tot_len); | |
148 | return c->base_reg + reg_offset; | |
afab2f7b MB |
149 | } |
150 | ||
cf57d607 DP |
151 | *pos = c->max; |
152 | ret = c->max_reg; | |
afab2f7b MB |
153 | } |
154 | ||
5166b7c0 | 155 | return ret; |
afab2f7b MB |
156 | } |
157 | ||
4dd7c553 DP |
158 | static inline void regmap_calc_tot_len(struct regmap *map, |
159 | void *buf, size_t count) | |
160 | { | |
161 | /* Calculate the length of a fixed format */ | |
162 | if (!map->debugfs_tot_len) { | |
163 | map->debugfs_reg_len = regmap_calc_reg_len(map->max_register, | |
164 | buf, count); | |
165 | map->debugfs_val_len = 2 * map->format.val_bytes; | |
166 | map->debugfs_tot_len = map->debugfs_reg_len + | |
167 | map->debugfs_val_len + 3; /* : \n */ | |
168 | } | |
169 | } | |
170 | ||
bd9cc12f MB |
171 | static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from, |
172 | unsigned int to, char __user *user_buf, | |
173 | size_t count, loff_t *ppos) | |
31244e39 | 174 | { |
31244e39 | 175 | size_t buf_pos = 0; |
afab2f7b | 176 | loff_t p = *ppos; |
31244e39 MB |
177 | ssize_t ret; |
178 | int i; | |
31244e39 | 179 | char *buf; |
afab2f7b | 180 | unsigned int val, start_reg; |
31244e39 MB |
181 | |
182 | if (*ppos < 0 || !count) | |
183 | return -EINVAL; | |
184 | ||
185 | buf = kmalloc(count, GFP_KERNEL); | |
186 | if (!buf) | |
187 | return -ENOMEM; | |
188 | ||
4dd7c553 | 189 | regmap_calc_tot_len(map, buf, count); |
31244e39 | 190 | |
afab2f7b MB |
191 | /* Work out which register we're starting at */ |
192 | start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p); | |
193 | ||
194 | for (i = start_reg; i <= to; i += map->reg_stride) { | |
8de2f081 | 195 | if (!regmap_readable(map, i)) |
31244e39 MB |
196 | continue; |
197 | ||
8de2f081 | 198 | if (regmap_precious(map, i)) |
2efe1642 MB |
199 | continue; |
200 | ||
31244e39 MB |
201 | /* If we're in the region the user is trying to read */ |
202 | if (p >= *ppos) { | |
203 | /* ...but not beyond it */ | |
f3eb8399 | 204 | if (buf_pos + map->debugfs_tot_len > count) |
31244e39 MB |
205 | break; |
206 | ||
207 | /* Format the register */ | |
208 | snprintf(buf + buf_pos, count - buf_pos, "%.*x: ", | |
cbc1938b MB |
209 | map->debugfs_reg_len, i - from); |
210 | buf_pos += map->debugfs_reg_len + 2; | |
31244e39 MB |
211 | |
212 | /* Format the value, write all X if we can't read */ | |
213 | ret = regmap_read(map, i, &val); | |
214 | if (ret == 0) | |
215 | snprintf(buf + buf_pos, count - buf_pos, | |
cbc1938b | 216 | "%.*x", map->debugfs_val_len, val); |
31244e39 | 217 | else |
cbc1938b MB |
218 | memset(buf + buf_pos, 'X', |
219 | map->debugfs_val_len); | |
31244e39 MB |
220 | buf_pos += 2 * map->format.val_bytes; |
221 | ||
222 | buf[buf_pos++] = '\n'; | |
223 | } | |
cbc1938b | 224 | p += map->debugfs_tot_len; |
31244e39 MB |
225 | } |
226 | ||
227 | ret = buf_pos; | |
228 | ||
229 | if (copy_to_user(user_buf, buf, buf_pos)) { | |
230 | ret = -EFAULT; | |
231 | goto out; | |
232 | } | |
233 | ||
234 | *ppos += buf_pos; | |
235 | ||
236 | out: | |
237 | kfree(buf); | |
238 | return ret; | |
239 | } | |
240 | ||
bd9cc12f MB |
241 | static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf, |
242 | size_t count, loff_t *ppos) | |
243 | { | |
244 | struct regmap *map = file->private_data; | |
245 | ||
246 | return regmap_read_debugfs(map, 0, map->max_register, user_buf, | |
247 | count, ppos); | |
248 | } | |
249 | ||
09c6ecd3 DP |
250 | #undef REGMAP_ALLOW_WRITE_DEBUGFS |
251 | #ifdef REGMAP_ALLOW_WRITE_DEBUGFS | |
252 | /* | |
253 | * This can be dangerous especially when we have clients such as | |
254 | * PMICs, therefore don't provide any real compile time configuration option | |
255 | * for this feature, people who want to use this will need to modify | |
256 | * the source code directly. | |
257 | */ | |
258 | static ssize_t regmap_map_write_file(struct file *file, | |
259 | const char __user *user_buf, | |
260 | size_t count, loff_t *ppos) | |
261 | { | |
262 | char buf[32]; | |
263 | size_t buf_size; | |
264 | char *start = buf; | |
265 | unsigned long reg, value; | |
266 | struct regmap *map = file->private_data; | |
267 | ||
268 | buf_size = min(count, (sizeof(buf)-1)); | |
269 | if (copy_from_user(buf, user_buf, buf_size)) | |
270 | return -EFAULT; | |
271 | buf[buf_size] = 0; | |
272 | ||
273 | while (*start == ' ') | |
274 | start++; | |
275 | reg = simple_strtoul(start, &start, 16); | |
276 | while (*start == ' ') | |
277 | start++; | |
278 | if (strict_strtoul(start, 16, &value)) | |
279 | return -EINVAL; | |
280 | ||
281 | /* Userspace has been fiddling around behind the kernel's back */ | |
373d4d09 | 282 | add_taint(TAINT_USER, LOCKDEP_NOW_UNRELIABLE); |
09c6ecd3 DP |
283 | |
284 | regmap_write(map, reg, value); | |
285 | return buf_size; | |
286 | } | |
287 | #else | |
288 | #define regmap_map_write_file NULL | |
289 | #endif | |
290 | ||
31244e39 | 291 | static const struct file_operations regmap_map_fops = { |
234e3405 | 292 | .open = simple_open, |
31244e39 | 293 | .read = regmap_map_read_file, |
09c6ecd3 | 294 | .write = regmap_map_write_file, |
31244e39 MB |
295 | .llseek = default_llseek, |
296 | }; | |
297 | ||
4b020b3f MB |
298 | static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf, |
299 | size_t count, loff_t *ppos) | |
300 | { | |
301 | struct regmap_range_node *range = file->private_data; | |
302 | struct regmap *map = range->map; | |
303 | ||
304 | return regmap_read_debugfs(map, range->range_min, range->range_max, | |
305 | user_buf, count, ppos); | |
306 | } | |
307 | ||
308 | static const struct file_operations regmap_range_fops = { | |
309 | .open = simple_open, | |
310 | .read = regmap_range_read_file, | |
311 | .llseek = default_llseek, | |
312 | }; | |
313 | ||
449e3842 MB |
314 | static ssize_t regmap_access_read_file(struct file *file, |
315 | char __user *user_buf, size_t count, | |
316 | loff_t *ppos) | |
317 | { | |
318 | int reg_len, tot_len; | |
319 | size_t buf_pos = 0; | |
320 | loff_t p = 0; | |
321 | ssize_t ret; | |
322 | int i; | |
323 | struct regmap *map = file->private_data; | |
324 | char *buf; | |
325 | ||
326 | if (*ppos < 0 || !count) | |
327 | return -EINVAL; | |
328 | ||
329 | buf = kmalloc(count, GFP_KERNEL); | |
330 | if (!buf) | |
331 | return -ENOMEM; | |
332 | ||
333 | /* Calculate the length of a fixed format */ | |
334 | reg_len = regmap_calc_reg_len(map->max_register, buf, count); | |
335 | tot_len = reg_len + 10; /* ': R W V P\n' */ | |
336 | ||
f01ee60f | 337 | for (i = 0; i <= map->max_register; i += map->reg_stride) { |
449e3842 MB |
338 | /* Ignore registers which are neither readable nor writable */ |
339 | if (!regmap_readable(map, i) && !regmap_writeable(map, i)) | |
340 | continue; | |
341 | ||
342 | /* If we're in the region the user is trying to read */ | |
343 | if (p >= *ppos) { | |
344 | /* ...but not beyond it */ | |
345 | if (buf_pos >= count - 1 - tot_len) | |
346 | break; | |
347 | ||
348 | /* Format the register */ | |
349 | snprintf(buf + buf_pos, count - buf_pos, | |
350 | "%.*x: %c %c %c %c\n", | |
351 | reg_len, i, | |
352 | regmap_readable(map, i) ? 'y' : 'n', | |
353 | regmap_writeable(map, i) ? 'y' : 'n', | |
354 | regmap_volatile(map, i) ? 'y' : 'n', | |
355 | regmap_precious(map, i) ? 'y' : 'n'); | |
356 | ||
357 | buf_pos += tot_len; | |
358 | } | |
359 | p += tot_len; | |
360 | } | |
361 | ||
362 | ret = buf_pos; | |
363 | ||
364 | if (copy_to_user(user_buf, buf, buf_pos)) { | |
365 | ret = -EFAULT; | |
366 | goto out; | |
367 | } | |
368 | ||
369 | *ppos += buf_pos; | |
370 | ||
371 | out: | |
372 | kfree(buf); | |
373 | return ret; | |
374 | } | |
375 | ||
376 | static const struct file_operations regmap_access_fops = { | |
234e3405 | 377 | .open = simple_open, |
449e3842 MB |
378 | .read = regmap_access_read_file, |
379 | .llseek = default_llseek, | |
380 | }; | |
31244e39 | 381 | |
d3c242e1 | 382 | void regmap_debugfs_init(struct regmap *map, const char *name) |
31244e39 | 383 | { |
4b020b3f MB |
384 | struct rb_node *next; |
385 | struct regmap_range_node *range_node; | |
386 | ||
5166b7c0 MB |
387 | INIT_LIST_HEAD(&map->debugfs_off_cache); |
388 | ||
d3c242e1 SW |
389 | if (name) { |
390 | map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s", | |
391 | dev_name(map->dev), name); | |
392 | name = map->debugfs_name; | |
393 | } else { | |
394 | name = dev_name(map->dev); | |
395 | } | |
396 | ||
397 | map->debugfs = debugfs_create_dir(name, regmap_debugfs_root); | |
31244e39 MB |
398 | if (!map->debugfs) { |
399 | dev_warn(map->dev, "Failed to create debugfs directory\n"); | |
400 | return; | |
401 | } | |
402 | ||
f0c2319f DP |
403 | debugfs_create_file("name", 0400, map->debugfs, |
404 | map, ®map_name_fops); | |
405 | ||
449e3842 | 406 | if (map->max_register) { |
31244e39 MB |
407 | debugfs_create_file("registers", 0400, map->debugfs, |
408 | map, ®map_map_fops); | |
449e3842 MB |
409 | debugfs_create_file("access", 0400, map->debugfs, |
410 | map, ®map_access_fops); | |
411 | } | |
028a01e6 MB |
412 | |
413 | if (map->cache_type) { | |
414 | debugfs_create_bool("cache_only", 0400, map->debugfs, | |
415 | &map->cache_only); | |
416 | debugfs_create_bool("cache_dirty", 0400, map->debugfs, | |
417 | &map->cache_dirty); | |
418 | debugfs_create_bool("cache_bypass", 0400, map->debugfs, | |
419 | &map->cache_bypass); | |
420 | } | |
4b020b3f MB |
421 | |
422 | next = rb_first(&map->range_tree); | |
423 | while (next) { | |
424 | range_node = rb_entry(next, struct regmap_range_node, node); | |
425 | ||
426 | if (range_node->name) | |
427 | debugfs_create_file(range_node->name, 0400, | |
428 | map->debugfs, range_node, | |
429 | ®map_range_fops); | |
430 | ||
431 | next = rb_next(&range_node->node); | |
432 | } | |
31244e39 MB |
433 | } |
434 | ||
435 | void regmap_debugfs_exit(struct regmap *map) | |
436 | { | |
437 | debugfs_remove_recursive(map->debugfs); | |
95f971c7 | 438 | regmap_debugfs_free_dump_cache(map); |
d3c242e1 | 439 | kfree(map->debugfs_name); |
31244e39 MB |
440 | } |
441 | ||
442 | void regmap_debugfs_initcall(void) | |
443 | { | |
444 | regmap_debugfs_root = debugfs_create_dir("regmap", NULL); | |
445 | if (!regmap_debugfs_root) { | |
446 | pr_warn("regmap: Failed to create debugfs root\n"); | |
447 | return; | |
448 | } | |
449 | } |