Merge branch 'broonie/spi-next' of git://git.kernel.org/pub/scm/linux/kernel/git...
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / drivers / base / regmap / regmap-debugfs.c
CommitLineData
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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>
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14#include <linux/mutex.h>
15#include <linux/debugfs.h>
16#include <linux/uaccess.h>
51990e82 17#include <linux/device.h>
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18
19#include "internal.h"
20
21static struct dentry *regmap_debugfs_root;
22
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23/* Calculate the length of a fixed format */
24static 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
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DP
30static 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
53static const struct file_operations regmap_name_fops = {
234e3405 54 .open = simple_open,
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55 .read = regmap_name_read_file,
56 .llseek = default_llseek,
57};
58
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59static 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
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72/*
73 * Work out where the start offset maps into register numbers, bearing
74 * in mind that we suppress hidden registers.
75 */
76static unsigned int regmap_debugfs_get_dump_start(struct regmap *map,
77 unsigned int base,
78 loff_t from,
79 loff_t *pos)
80{
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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);
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107 if (!c) {
108 regmap_debugfs_free_dump_cache(map);
109 return base;
110 }
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111 c->min = p;
112 c->base_reg = i;
113 }
114
115 p += map->debugfs_tot_len;
116 }
117 }
afab2f7b 118
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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);
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124 }
125
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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
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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) {
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139 *pos = c->min;
140 return c->base_reg;
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141 }
142
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143 *pos = c->min;
144 ret = c->base_reg;
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145 }
146
5166b7c0 147 return ret;
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148}
149
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150static 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;
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156 ssize_t ret;
157 int i;
31244e39 158 char *buf;
afab2f7b 159 unsigned int val, start_reg;
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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 */
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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
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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))
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182 continue;
183
8de2f081 184 if (regmap_precious(map, i))
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185 continue;
186
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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)
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191 break;
192
193 /* Format the register */
194 snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
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195 map->debugfs_reg_len, i - from);
196 buf_pos += map->debugfs_reg_len + 2;
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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
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204 memset(buf + buf_pos, 'X',
205 map->debugfs_val_len);
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206 buf_pos += 2 * map->format.val_bytes;
207
208 buf[buf_pos++] = '\n';
209 }
cbc1938b 210 p += map->debugfs_tot_len;
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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
222out:
223 kfree(buf);
224 return ret;
225}
226
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227static 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
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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 */
244static 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 277static 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,
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281 .llseek = default_llseek,
282};
283
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284static 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
294static const struct file_operations regmap_range_fops = {
295 .open = simple_open,
296 .read = regmap_range_read_file,
297 .llseek = default_llseek,
298};
299
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300static 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) {
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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
357out:
358 kfree(buf);
359 return ret;
360}
361
362static const struct file_operations regmap_access_fops = {
234e3405 363 .open = simple_open,
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364 .read = regmap_access_read_file,
365 .llseek = default_llseek,
366};
31244e39 367
d3c242e1 368void regmap_debugfs_init(struct regmap *map, const char *name)
31244e39 369{
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370 struct rb_node *next;
371 struct regmap_range_node *range_node;
372
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373 INIT_LIST_HEAD(&map->debugfs_off_cache);
374
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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);
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384 if (!map->debugfs) {
385 dev_warn(map->dev, "Failed to create debugfs directory\n");
386 return;
387 }
388
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389 debugfs_create_file("name", 0400, map->debugfs,
390 map, &regmap_name_fops);
391
449e3842 392 if (map->max_register) {
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393 debugfs_create_file("registers", 0400, map->debugfs,
394 map, &regmap_map_fops);
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395 debugfs_create_file("access", 0400, map->debugfs,
396 map, &regmap_access_fops);
397 }
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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 }
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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 &regmap_range_fops);
416
417 next = rb_next(&range_node->node);
418 }
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419}
420
421void 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);
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426}
427
428void 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}