Merge tag 'regmap-3.9' of git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap
[~shefty/rdma-dev.git] / drivers / base / regmap / regmap-debugfs.c
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>
14 #include <linux/mutex.h>
15 #include <linux/debugfs.h>
16 #include <linux/uaccess.h>
17 #include <linux/device.h>
18
19 #include "internal.h"
20
21 static struct dentry *regmap_debugfs_root;
22
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
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 = {
54         .open = simple_open,
55         .read = regmap_name_read_file,
56         .llseek = default_llseek,
57 };
58
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
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 {
81         struct regmap_debugfs_off_cache *c = NULL;
82         loff_t p = 0;
83         unsigned int i, ret;
84         unsigned int fpos_offset;
85         unsigned int reg_offset;
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;
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;
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);
112                                 if (!c) {
113                                         regmap_debugfs_free_dump_cache(map);
114                                         return base;
115                                 }
116                                 c->min = p;
117                                 c->base_reg = i;
118                         }
119
120                         p += map->debugfs_tot_len;
121                 }
122         }
123
124         /* Close the last entry off if we didn't scan beyond it */
125         if (c) {
126                 c->max = p - 1;
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;
130                 list_add_tail(&c->list,
131                               &map->debugfs_off_cache);
132         }
133
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          */
139         WARN_ON(list_empty(&map->debugfs_off_cache));
140         ret = base;
141
142         /* Find the relevant block:offset */
143         list_for_each_entry(c, &map->debugfs_off_cache, list) {
144                 if (from >= c->min && from <= c->max) {
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;
149                 }
150
151                 *pos = c->max;
152                 ret = c->max_reg;
153         }
154
155         return ret;
156 }
157
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
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)
174 {
175         size_t buf_pos = 0;
176         loff_t p = *ppos;
177         ssize_t ret;
178         int i;
179         char *buf;
180         unsigned int val, start_reg;
181
182         if (*ppos < 0 || !count)
183                 return -EINVAL;
184
185         buf = kmalloc(count, GFP_KERNEL);
186         if (!buf)
187                 return -ENOMEM;
188
189         regmap_calc_tot_len(map, buf, count);
190
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) {
195                 if (!regmap_readable(map, i))
196                         continue;
197
198                 if (regmap_precious(map, i))
199                         continue;
200
201                 /* If we're in the region the user is trying to read */
202                 if (p >= *ppos) {
203                         /* ...but not beyond it */
204                         if (buf_pos + map->debugfs_tot_len > count)
205                                 break;
206
207                         /* Format the register */
208                         snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
209                                  map->debugfs_reg_len, i - from);
210                         buf_pos += map->debugfs_reg_len + 2;
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,
216                                          "%.*x", map->debugfs_val_len, val);
217                         else
218                                 memset(buf + buf_pos, 'X',
219                                        map->debugfs_val_len);
220                         buf_pos += 2 * map->format.val_bytes;
221
222                         buf[buf_pos++] = '\n';
223                 }
224                 p += map->debugfs_tot_len;
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
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
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 */
282         add_taint(TAINT_USER);
283
284         regmap_write(map, reg, value);
285         return buf_size;
286 }
287 #else
288 #define regmap_map_write_file NULL
289 #endif
290
291 static const struct file_operations regmap_map_fops = {
292         .open = simple_open,
293         .read = regmap_map_read_file,
294         .write = regmap_map_write_file,
295         .llseek = default_llseek,
296 };
297
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
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
337         for (i = 0; i <= map->max_register; i += map->reg_stride) {
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 = {
377         .open = simple_open,
378         .read = regmap_access_read_file,
379         .llseek = default_llseek,
380 };
381
382 void regmap_debugfs_init(struct regmap *map, const char *name)
383 {
384         struct rb_node *next;
385         struct regmap_range_node *range_node;
386
387         INIT_LIST_HEAD(&map->debugfs_off_cache);
388
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);
398         if (!map->debugfs) {
399                 dev_warn(map->dev, "Failed to create debugfs directory\n");
400                 return;
401         }
402
403         debugfs_create_file("name", 0400, map->debugfs,
404                             map, &regmap_name_fops);
405
406         if (map->max_register) {
407                 debugfs_create_file("registers", 0400, map->debugfs,
408                                     map, &regmap_map_fops);
409                 debugfs_create_file("access", 0400, map->debugfs,
410                                     map, &regmap_access_fops);
411         }
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         }
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                                             &regmap_range_fops);
430
431                 next = rb_next(&range_node->node);
432         }
433 }
434
435 void regmap_debugfs_exit(struct regmap *map)
436 {
437         debugfs_remove_recursive(map->debugfs);
438         regmap_debugfs_free_dump_cache(map);
439         kfree(map->debugfs_name);
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 }