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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; | |
84 | ||
85 | /* | |
86 | * If we don't have a cache build one so we don't have to do a | |
87 | * linear scan each time. | |
88 | */ | |
89 | if (list_empty(&map->debugfs_off_cache)) { | |
90 | for (i = base; i <= map->max_register; i += map->reg_stride) { | |
91 | /* Skip unprinted registers, closing off cache entry */ | |
92 | if (!regmap_readable(map, i) || | |
93 | regmap_precious(map, i)) { | |
94 | if (c) { | |
95 | c->max = p - 1; | |
96 | list_add_tail(&c->list, | |
97 | &map->debugfs_off_cache); | |
98 | c = NULL; | |
99 | } | |
100 | ||
101 | continue; | |
102 | } | |
103 | ||
104 | /* No cache entry? Start a new one */ | |
105 | if (!c) { | |
106 | c = kzalloc(sizeof(*c), GFP_KERNEL); | |
95f971c7 MB |
107 | if (!c) { |
108 | regmap_debugfs_free_dump_cache(map); | |
109 | return base; | |
110 | } | |
5166b7c0 MB |
111 | c->min = p; |
112 | c->base_reg = i; | |
113 | } | |
114 | ||
115 | p += map->debugfs_tot_len; | |
116 | } | |
117 | } | |
afab2f7b | 118 | |
e8d6539c MB |
119 | /* Close the last entry off if we didn't scan beyond it */ |
120 | if (c) { | |
121 | c->max = p - 1; | |
122 | list_add_tail(&c->list, | |
123 | &map->debugfs_off_cache); | |
e8d6539c MB |
124 | } |
125 | ||
5bd9f4bb MB |
126 | /* |
127 | * This should never happen; we return above if we fail to | |
128 | * allocate and we should never be in this code if there are | |
129 | * no registers at all. | |
130 | */ | |
131 | if (list_empty(&map->debugfs_off_cache)) { | |
132 | WARN_ON(list_empty(&map->debugfs_off_cache)); | |
133 | return base; | |
134 | } | |
135 | ||
5166b7c0 MB |
136 | /* Find the relevant block */ |
137 | list_for_each_entry(c, &map->debugfs_off_cache, list) { | |
5a1d6d17 | 138 | if (from >= c->min && from <= c->max) { |
5166b7c0 MB |
139 | *pos = c->min; |
140 | return c->base_reg; | |
afab2f7b MB |
141 | } |
142 | ||
120f8051 MB |
143 | *pos = c->min; |
144 | ret = c->base_reg; | |
afab2f7b MB |
145 | } |
146 | ||
5166b7c0 | 147 | return ret; |
afab2f7b MB |
148 | } |
149 | ||
bd9cc12f MB |
150 | static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from, |
151 | unsigned int to, char __user *user_buf, | |
152 | size_t count, loff_t *ppos) | |
31244e39 | 153 | { |
31244e39 | 154 | size_t buf_pos = 0; |
afab2f7b | 155 | loff_t p = *ppos; |
31244e39 MB |
156 | ssize_t ret; |
157 | int i; | |
31244e39 | 158 | char *buf; |
afab2f7b | 159 | unsigned int val, start_reg; |
31244e39 MB |
160 | |
161 | if (*ppos < 0 || !count) | |
162 | return -EINVAL; | |
163 | ||
164 | buf = kmalloc(count, GFP_KERNEL); | |
165 | if (!buf) | |
166 | return -ENOMEM; | |
167 | ||
168 | /* Calculate the length of a fixed format */ | |
cbc1938b MB |
169 | if (!map->debugfs_tot_len) { |
170 | map->debugfs_reg_len = regmap_calc_reg_len(map->max_register, | |
171 | buf, count); | |
172 | map->debugfs_val_len = 2 * map->format.val_bytes; | |
173 | map->debugfs_tot_len = map->debugfs_reg_len + | |
174 | map->debugfs_val_len + 3; /* : \n */ | |
175 | } | |
31244e39 | 176 | |
afab2f7b MB |
177 | /* Work out which register we're starting at */ |
178 | start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p); | |
179 | ||
180 | for (i = start_reg; i <= to; i += map->reg_stride) { | |
8de2f081 | 181 | if (!regmap_readable(map, i)) |
31244e39 MB |
182 | continue; |
183 | ||
8de2f081 | 184 | if (regmap_precious(map, i)) |
2efe1642 MB |
185 | continue; |
186 | ||
31244e39 MB |
187 | /* If we're in the region the user is trying to read */ |
188 | if (p >= *ppos) { | |
189 | /* ...but not beyond it */ | |
db04328c | 190 | if (buf_pos + 1 + map->debugfs_tot_len >= count) |
31244e39 MB |
191 | break; |
192 | ||
193 | /* Format the register */ | |
194 | snprintf(buf + buf_pos, count - buf_pos, "%.*x: ", | |
cbc1938b MB |
195 | map->debugfs_reg_len, i - from); |
196 | buf_pos += map->debugfs_reg_len + 2; | |
31244e39 MB |
197 | |
198 | /* Format the value, write all X if we can't read */ | |
199 | ret = regmap_read(map, i, &val); | |
200 | if (ret == 0) | |
201 | snprintf(buf + buf_pos, count - buf_pos, | |
cbc1938b | 202 | "%.*x", map->debugfs_val_len, val); |
31244e39 | 203 | else |
cbc1938b MB |
204 | memset(buf + buf_pos, 'X', |
205 | map->debugfs_val_len); | |
31244e39 MB |
206 | buf_pos += 2 * map->format.val_bytes; |
207 | ||
208 | buf[buf_pos++] = '\n'; | |
209 | } | |
cbc1938b | 210 | p += map->debugfs_tot_len; |
31244e39 MB |
211 | } |
212 | ||
213 | ret = buf_pos; | |
214 | ||
215 | if (copy_to_user(user_buf, buf, buf_pos)) { | |
216 | ret = -EFAULT; | |
217 | goto out; | |
218 | } | |
219 | ||
220 | *ppos += buf_pos; | |
221 | ||
222 | out: | |
223 | kfree(buf); | |
224 | return ret; | |
225 | } | |
226 | ||
bd9cc12f MB |
227 | static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf, |
228 | size_t count, loff_t *ppos) | |
229 | { | |
230 | struct regmap *map = file->private_data; | |
231 | ||
232 | return regmap_read_debugfs(map, 0, map->max_register, user_buf, | |
233 | count, ppos); | |
234 | } | |
235 | ||
09c6ecd3 DP |
236 | #undef REGMAP_ALLOW_WRITE_DEBUGFS |
237 | #ifdef REGMAP_ALLOW_WRITE_DEBUGFS | |
238 | /* | |
239 | * This can be dangerous especially when we have clients such as | |
240 | * PMICs, therefore don't provide any real compile time configuration option | |
241 | * for this feature, people who want to use this will need to modify | |
242 | * the source code directly. | |
243 | */ | |
244 | static ssize_t regmap_map_write_file(struct file *file, | |
245 | const char __user *user_buf, | |
246 | size_t count, loff_t *ppos) | |
247 | { | |
248 | char buf[32]; | |
249 | size_t buf_size; | |
250 | char *start = buf; | |
251 | unsigned long reg, value; | |
252 | struct regmap *map = file->private_data; | |
253 | ||
254 | buf_size = min(count, (sizeof(buf)-1)); | |
255 | if (copy_from_user(buf, user_buf, buf_size)) | |
256 | return -EFAULT; | |
257 | buf[buf_size] = 0; | |
258 | ||
259 | while (*start == ' ') | |
260 | start++; | |
261 | reg = simple_strtoul(start, &start, 16); | |
262 | while (*start == ' ') | |
263 | start++; | |
264 | if (strict_strtoul(start, 16, &value)) | |
265 | return -EINVAL; | |
266 | ||
267 | /* Userspace has been fiddling around behind the kernel's back */ | |
268 | add_taint(TAINT_USER); | |
269 | ||
270 | regmap_write(map, reg, value); | |
271 | return buf_size; | |
272 | } | |
273 | #else | |
274 | #define regmap_map_write_file NULL | |
275 | #endif | |
276 | ||
31244e39 | 277 | static const struct file_operations regmap_map_fops = { |
234e3405 | 278 | .open = simple_open, |
31244e39 | 279 | .read = regmap_map_read_file, |
09c6ecd3 | 280 | .write = regmap_map_write_file, |
31244e39 MB |
281 | .llseek = default_llseek, |
282 | }; | |
283 | ||
4b020b3f MB |
284 | static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf, |
285 | size_t count, loff_t *ppos) | |
286 | { | |
287 | struct regmap_range_node *range = file->private_data; | |
288 | struct regmap *map = range->map; | |
289 | ||
290 | return regmap_read_debugfs(map, range->range_min, range->range_max, | |
291 | user_buf, count, ppos); | |
292 | } | |
293 | ||
294 | static const struct file_operations regmap_range_fops = { | |
295 | .open = simple_open, | |
296 | .read = regmap_range_read_file, | |
297 | .llseek = default_llseek, | |
298 | }; | |
299 | ||
449e3842 MB |
300 | static ssize_t regmap_access_read_file(struct file *file, |
301 | char __user *user_buf, size_t count, | |
302 | loff_t *ppos) | |
303 | { | |
304 | int reg_len, tot_len; | |
305 | size_t buf_pos = 0; | |
306 | loff_t p = 0; | |
307 | ssize_t ret; | |
308 | int i; | |
309 | struct regmap *map = file->private_data; | |
310 | char *buf; | |
311 | ||
312 | if (*ppos < 0 || !count) | |
313 | return -EINVAL; | |
314 | ||
315 | buf = kmalloc(count, GFP_KERNEL); | |
316 | if (!buf) | |
317 | return -ENOMEM; | |
318 | ||
319 | /* Calculate the length of a fixed format */ | |
320 | reg_len = regmap_calc_reg_len(map->max_register, buf, count); | |
321 | tot_len = reg_len + 10; /* ': R W V P\n' */ | |
322 | ||
f01ee60f | 323 | for (i = 0; i <= map->max_register; i += map->reg_stride) { |
449e3842 MB |
324 | /* Ignore registers which are neither readable nor writable */ |
325 | if (!regmap_readable(map, i) && !regmap_writeable(map, i)) | |
326 | continue; | |
327 | ||
328 | /* If we're in the region the user is trying to read */ | |
329 | if (p >= *ppos) { | |
330 | /* ...but not beyond it */ | |
331 | if (buf_pos >= count - 1 - tot_len) | |
332 | break; | |
333 | ||
334 | /* Format the register */ | |
335 | snprintf(buf + buf_pos, count - buf_pos, | |
336 | "%.*x: %c %c %c %c\n", | |
337 | reg_len, i, | |
338 | regmap_readable(map, i) ? 'y' : 'n', | |
339 | regmap_writeable(map, i) ? 'y' : 'n', | |
340 | regmap_volatile(map, i) ? 'y' : 'n', | |
341 | regmap_precious(map, i) ? 'y' : 'n'); | |
342 | ||
343 | buf_pos += tot_len; | |
344 | } | |
345 | p += tot_len; | |
346 | } | |
347 | ||
348 | ret = buf_pos; | |
349 | ||
350 | if (copy_to_user(user_buf, buf, buf_pos)) { | |
351 | ret = -EFAULT; | |
352 | goto out; | |
353 | } | |
354 | ||
355 | *ppos += buf_pos; | |
356 | ||
357 | out: | |
358 | kfree(buf); | |
359 | return ret; | |
360 | } | |
361 | ||
362 | static const struct file_operations regmap_access_fops = { | |
234e3405 | 363 | .open = simple_open, |
449e3842 MB |
364 | .read = regmap_access_read_file, |
365 | .llseek = default_llseek, | |
366 | }; | |
31244e39 | 367 | |
d3c242e1 | 368 | void regmap_debugfs_init(struct regmap *map, const char *name) |
31244e39 | 369 | { |
4b020b3f MB |
370 | struct rb_node *next; |
371 | struct regmap_range_node *range_node; | |
372 | ||
5166b7c0 MB |
373 | INIT_LIST_HEAD(&map->debugfs_off_cache); |
374 | ||
d3c242e1 SW |
375 | if (name) { |
376 | map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s", | |
377 | dev_name(map->dev), name); | |
378 | name = map->debugfs_name; | |
379 | } else { | |
380 | name = dev_name(map->dev); | |
381 | } | |
382 | ||
383 | map->debugfs = debugfs_create_dir(name, regmap_debugfs_root); | |
31244e39 MB |
384 | if (!map->debugfs) { |
385 | dev_warn(map->dev, "Failed to create debugfs directory\n"); | |
386 | return; | |
387 | } | |
388 | ||
f0c2319f DP |
389 | debugfs_create_file("name", 0400, map->debugfs, |
390 | map, ®map_name_fops); | |
391 | ||
449e3842 | 392 | if (map->max_register) { |
31244e39 MB |
393 | debugfs_create_file("registers", 0400, map->debugfs, |
394 | map, ®map_map_fops); | |
449e3842 MB |
395 | debugfs_create_file("access", 0400, map->debugfs, |
396 | map, ®map_access_fops); | |
397 | } | |
028a01e6 MB |
398 | |
399 | if (map->cache_type) { | |
400 | debugfs_create_bool("cache_only", 0400, map->debugfs, | |
401 | &map->cache_only); | |
402 | debugfs_create_bool("cache_dirty", 0400, map->debugfs, | |
403 | &map->cache_dirty); | |
404 | debugfs_create_bool("cache_bypass", 0400, map->debugfs, | |
405 | &map->cache_bypass); | |
406 | } | |
4b020b3f MB |
407 | |
408 | next = rb_first(&map->range_tree); | |
409 | while (next) { | |
410 | range_node = rb_entry(next, struct regmap_range_node, node); | |
411 | ||
412 | if (range_node->name) | |
413 | debugfs_create_file(range_node->name, 0400, | |
414 | map->debugfs, range_node, | |
415 | ®map_range_fops); | |
416 | ||
417 | next = rb_next(&range_node->node); | |
418 | } | |
31244e39 MB |
419 | } |
420 | ||
421 | void regmap_debugfs_exit(struct regmap *map) | |
422 | { | |
423 | debugfs_remove_recursive(map->debugfs); | |
95f971c7 | 424 | regmap_debugfs_free_dump_cache(map); |
d3c242e1 | 425 | kfree(map->debugfs_name); |
31244e39 MB |
426 | } |
427 | ||
428 | void regmap_debugfs_initcall(void) | |
429 | { | |
430 | regmap_debugfs_root = debugfs_create_dir("regmap", NULL); | |
431 | if (!regmap_debugfs_root) { | |
432 | pr_warn("regmap: Failed to create debugfs root\n"); | |
433 | return; | |
434 | } | |
435 | } |