Merge branch 'for-3.9-cpuset' of git://git.kernel.org/pub/scm/linux/kernel/git/tj...
[~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
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);
107                                 if (!c) {
108                                         regmap_debugfs_free_dump_cache(map);
109                                         return base;
110                                 }
111                                 c->min = p;
112                                 c->base_reg = i;
113                         }
114
115                         p += map->debugfs_tot_len;
116                 }
117         }
118
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);
124         }
125
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
136         /* Find the relevant block */
137         list_for_each_entry(c, &map->debugfs_off_cache, list) {
138                 if (from >= c->min && from <= c->max) {
139                         *pos = c->min;
140                         return c->base_reg;
141                 }
142
143                 *pos = c->min;
144                 ret = c->base_reg;
145         }
146
147         return ret;
148 }
149
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)
153 {
154         size_t buf_pos = 0;
155         loff_t p = *ppos;
156         ssize_t ret;
157         int i;
158         char *buf;
159         unsigned int val, start_reg;
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  */
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         }
176
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) {
181                 if (!regmap_readable(map, i))
182                         continue;
183
184                 if (regmap_precious(map, i))
185                         continue;
186
187                 /* If we're in the region the user is trying to read */
188                 if (p >= *ppos) {
189                         /* ...but not beyond it */
190                         if (buf_pos + 1 + map->debugfs_tot_len >= count)
191                                 break;
192
193                         /* Format the register */
194                         snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
195                                  map->debugfs_reg_len, i - from);
196                         buf_pos += map->debugfs_reg_len + 2;
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,
202                                          "%.*x", map->debugfs_val_len, val);
203                         else
204                                 memset(buf + buf_pos, 'X',
205                                        map->debugfs_val_len);
206                         buf_pos += 2 * map->format.val_bytes;
207
208                         buf[buf_pos++] = '\n';
209                 }
210                 p += map->debugfs_tot_len;
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
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
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
277 static const struct file_operations regmap_map_fops = {
278         .open = simple_open,
279         .read = regmap_map_read_file,
280         .write = regmap_map_write_file,
281         .llseek = default_llseek,
282 };
283
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
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
323         for (i = 0; i <= map->max_register; i += map->reg_stride) {
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 = {
363         .open = simple_open,
364         .read = regmap_access_read_file,
365         .llseek = default_llseek,
366 };
367
368 void regmap_debugfs_init(struct regmap *map, const char *name)
369 {
370         struct rb_node *next;
371         struct regmap_range_node *range_node;
372
373         INIT_LIST_HEAD(&map->debugfs_off_cache);
374
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);
384         if (!map->debugfs) {
385                 dev_warn(map->dev, "Failed to create debugfs directory\n");
386                 return;
387         }
388
389         debugfs_create_file("name", 0400, map->debugfs,
390                             map, &regmap_name_fops);
391
392         if (map->max_register) {
393                 debugfs_create_file("registers", 0400, map->debugfs,
394                                     map, &regmap_map_fops);
395                 debugfs_create_file("access", 0400, map->debugfs,
396                                     map, &regmap_access_fops);
397         }
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         }
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         }
419 }
420
421 void regmap_debugfs_exit(struct regmap *map)
422 {
423         debugfs_remove_recursive(map->debugfs);
424         regmap_debugfs_free_dump_cache(map);
425         kfree(map->debugfs_name);
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 }