regcache: Make sure we sync register 0 in an rbtree cache
[linux-2.6.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
18 #include "internal.h"
19
20 static struct dentry *regmap_debugfs_root;
21
22 /* Calculate the length of a fixed format  */
23 static size_t regmap_calc_reg_len(int max_val, char *buf, size_t buf_size)
24 {
25         snprintf(buf, buf_size, "%x", max_val);
26         return strlen(buf);
27 }
28
29 static int regmap_open_file(struct inode *inode, struct file *file)
30 {
31         file->private_data = inode->i_private;
32         return 0;
33 }
34
35 static ssize_t regmap_name_read_file(struct file *file,
36                                      char __user *user_buf, size_t count,
37                                      loff_t *ppos)
38 {
39         struct regmap *map = file->private_data;
40         int ret;
41         char *buf;
42
43         buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
44         if (!buf)
45                 return -ENOMEM;
46
47         ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name);
48         if (ret < 0) {
49                 kfree(buf);
50                 return ret;
51         }
52
53         ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
54         kfree(buf);
55         return ret;
56 }
57
58 static const struct file_operations regmap_name_fops = {
59         .open = regmap_open_file,
60         .read = regmap_name_read_file,
61         .llseek = default_llseek,
62 };
63
64 static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
65                                     size_t count, loff_t *ppos)
66 {
67         int reg_len, val_len, tot_len;
68         size_t buf_pos = 0;
69         loff_t p = 0;
70         ssize_t ret;
71         int i;
72         struct regmap *map = file->private_data;
73         char *buf;
74         unsigned int val;
75
76         if (*ppos < 0 || !count)
77                 return -EINVAL;
78
79         buf = kmalloc(count, GFP_KERNEL);
80         if (!buf)
81                 return -ENOMEM;
82
83         /* Calculate the length of a fixed format  */
84         reg_len = regmap_calc_reg_len(map->max_register, buf, count);
85         val_len = 2 * map->format.val_bytes;
86         tot_len = reg_len + val_len + 3;      /* : \n */
87
88         for (i = 0; i < map->max_register + 1; i++) {
89                 if (!regmap_readable(map, i))
90                         continue;
91
92                 if (regmap_precious(map, i))
93                         continue;
94
95                 /* If we're in the region the user is trying to read */
96                 if (p >= *ppos) {
97                         /* ...but not beyond it */
98                         if (buf_pos >= count - 1 - tot_len)
99                                 break;
100
101                         /* Format the register */
102                         snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
103                                  reg_len, i);
104                         buf_pos += reg_len + 2;
105
106                         /* Format the value, write all X if we can't read */
107                         ret = regmap_read(map, i, &val);
108                         if (ret == 0)
109                                 snprintf(buf + buf_pos, count - buf_pos,
110                                          "%.*x", val_len, val);
111                         else
112                                 memset(buf + buf_pos, 'X', val_len);
113                         buf_pos += 2 * map->format.val_bytes;
114
115                         buf[buf_pos++] = '\n';
116                 }
117                 p += tot_len;
118         }
119
120         ret = buf_pos;
121
122         if (copy_to_user(user_buf, buf, buf_pos)) {
123                 ret = -EFAULT;
124                 goto out;
125         }
126
127         *ppos += buf_pos;
128
129 out:
130         kfree(buf);
131         return ret;
132 }
133
134 #undef REGMAP_ALLOW_WRITE_DEBUGFS
135 #ifdef REGMAP_ALLOW_WRITE_DEBUGFS
136 /*
137  * This can be dangerous especially when we have clients such as
138  * PMICs, therefore don't provide any real compile time configuration option
139  * for this feature, people who want to use this will need to modify
140  * the source code directly.
141  */
142 static ssize_t regmap_map_write_file(struct file *file,
143                                      const char __user *user_buf,
144                                      size_t count, loff_t *ppos)
145 {
146         char buf[32];
147         size_t buf_size;
148         char *start = buf;
149         unsigned long reg, value;
150         struct regmap *map = file->private_data;
151
152         buf_size = min(count, (sizeof(buf)-1));
153         if (copy_from_user(buf, user_buf, buf_size))
154                 return -EFAULT;
155         buf[buf_size] = 0;
156
157         while (*start == ' ')
158                 start++;
159         reg = simple_strtoul(start, &start, 16);
160         while (*start == ' ')
161                 start++;
162         if (strict_strtoul(start, 16, &value))
163                 return -EINVAL;
164
165         /* Userspace has been fiddling around behind the kernel's back */
166         add_taint(TAINT_USER);
167
168         regmap_write(map, reg, value);
169         return buf_size;
170 }
171 #else
172 #define regmap_map_write_file NULL
173 #endif
174
175 static const struct file_operations regmap_map_fops = {
176         .open = regmap_open_file,
177         .read = regmap_map_read_file,
178         .write = regmap_map_write_file,
179         .llseek = default_llseek,
180 };
181
182 static ssize_t regmap_access_read_file(struct file *file,
183                                        char __user *user_buf, size_t count,
184                                        loff_t *ppos)
185 {
186         int reg_len, tot_len;
187         size_t buf_pos = 0;
188         loff_t p = 0;
189         ssize_t ret;
190         int i;
191         struct regmap *map = file->private_data;
192         char *buf;
193
194         if (*ppos < 0 || !count)
195                 return -EINVAL;
196
197         buf = kmalloc(count, GFP_KERNEL);
198         if (!buf)
199                 return -ENOMEM;
200
201         /* Calculate the length of a fixed format  */
202         reg_len = regmap_calc_reg_len(map->max_register, buf, count);
203         tot_len = reg_len + 10; /* ': R W V P\n' */
204
205         for (i = 0; i < map->max_register + 1; i++) {
206                 /* Ignore registers which are neither readable nor writable */
207                 if (!regmap_readable(map, i) && !regmap_writeable(map, i))
208                         continue;
209
210                 /* If we're in the region the user is trying to read */
211                 if (p >= *ppos) {
212                         /* ...but not beyond it */
213                         if (buf_pos >= count - 1 - tot_len)
214                                 break;
215
216                         /* Format the register */
217                         snprintf(buf + buf_pos, count - buf_pos,
218                                  "%.*x: %c %c %c %c\n",
219                                  reg_len, i,
220                                  regmap_readable(map, i) ? 'y' : 'n',
221                                  regmap_writeable(map, i) ? 'y' : 'n',
222                                  regmap_volatile(map, i) ? 'y' : 'n',
223                                  regmap_precious(map, i) ? 'y' : 'n');
224
225                         buf_pos += tot_len;
226                 }
227                 p += tot_len;
228         }
229
230         ret = buf_pos;
231
232         if (copy_to_user(user_buf, buf, buf_pos)) {
233                 ret = -EFAULT;
234                 goto out;
235         }
236
237         *ppos += buf_pos;
238
239 out:
240         kfree(buf);
241         return ret;
242 }
243
244 static const struct file_operations regmap_access_fops = {
245         .open = regmap_open_file,
246         .read = regmap_access_read_file,
247         .llseek = default_llseek,
248 };
249
250 void regmap_debugfs_init(struct regmap *map)
251 {
252         map->debugfs = debugfs_create_dir(dev_name(map->dev),
253                                           regmap_debugfs_root);
254         if (!map->debugfs) {
255                 dev_warn(map->dev, "Failed to create debugfs directory\n");
256                 return;
257         }
258
259         debugfs_create_file("name", 0400, map->debugfs,
260                             map, &regmap_name_fops);
261
262         if (map->max_register) {
263                 debugfs_create_file("registers", 0400, map->debugfs,
264                                     map, &regmap_map_fops);
265                 debugfs_create_file("access", 0400, map->debugfs,
266                                     map, &regmap_access_fops);
267         }
268
269         if (map->cache_type) {
270                 debugfs_create_bool("cache_only", 0400, map->debugfs,
271                                     &map->cache_only);
272                 debugfs_create_bool("cache_dirty", 0400, map->debugfs,
273                                     &map->cache_dirty);
274                 debugfs_create_bool("cache_bypass", 0400, map->debugfs,
275                                     &map->cache_bypass);
276         }
277 }
278
279 void regmap_debugfs_exit(struct regmap *map)
280 {
281         debugfs_remove_recursive(map->debugfs);
282 }
283
284 void regmap_debugfs_initcall(void)
285 {
286         regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
287         if (!regmap_debugfs_root) {
288                 pr_warn("regmap: Failed to create debugfs root\n");
289                 return;
290         }
291 }