2 * Register map access API - debugfs
4 * Copyright 2011 Wolfson Microelectronics plc
6 * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
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.
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>
21 static struct dentry *regmap_debugfs_root;
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)
26 snprintf(buf, buf_size, "%x", max_val);
30 static ssize_t regmap_name_read_file(struct file *file,
31 char __user *user_buf, size_t count,
34 struct regmap *map = file->private_data;
38 buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
42 ret = snprintf(buf, PAGE_SIZE, "%s\n", map->dev->driver->name);
48 ret = simple_read_from_buffer(user_buf, count, ppos, buf, ret);
53 static const struct file_operations regmap_name_fops = {
55 .read = regmap_name_read_file,
56 .llseek = default_llseek,
60 * Work out where the start offset maps into register numbers, bearing
61 * in mind that we suppress hidden registers.
63 static unsigned int regmap_debugfs_get_dump_start(struct regmap *map,
68 struct regmap_debugfs_off_cache *c = NULL;
73 * If we don't have a cache build one so we don't have to do a
74 * linear scan each time.
76 if (list_empty(&map->debugfs_off_cache)) {
77 for (i = base; i <= map->max_register; i += map->reg_stride) {
78 /* Skip unprinted registers, closing off cache entry */
79 if (!regmap_readable(map, i) ||
80 regmap_precious(map, i)) {
83 list_add_tail(&c->list,
84 &map->debugfs_off_cache);
91 /* No cache entry? Start a new one */
93 c = kzalloc(sizeof(*c), GFP_KERNEL);
100 p += map->debugfs_tot_len;
104 /* Find the relevant block */
105 list_for_each_entry(c, &map->debugfs_off_cache, list) {
106 if (*pos >= c->min && *pos <= c->max) {
117 static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
118 unsigned int to, char __user *user_buf,
119 size_t count, loff_t *ppos)
126 unsigned int val, start_reg;
128 if (*ppos < 0 || !count)
131 buf = kmalloc(count, GFP_KERNEL);
135 /* Calculate the length of a fixed format */
136 if (!map->debugfs_tot_len) {
137 map->debugfs_reg_len = regmap_calc_reg_len(map->max_register,
139 map->debugfs_val_len = 2 * map->format.val_bytes;
140 map->debugfs_tot_len = map->debugfs_reg_len +
141 map->debugfs_val_len + 3; /* : \n */
144 /* Work out which register we're starting at */
145 start_reg = regmap_debugfs_get_dump_start(map, from, *ppos, &p);
147 for (i = start_reg; i <= to; i += map->reg_stride) {
148 if (!regmap_readable(map, i))
151 if (regmap_precious(map, i))
154 /* If we're in the region the user is trying to read */
156 /* ...but not beyond it */
157 if (buf_pos + 1 + map->debugfs_tot_len >= count)
160 /* Format the register */
161 snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
162 map->debugfs_reg_len, i - from);
163 buf_pos += map->debugfs_reg_len + 2;
165 /* Format the value, write all X if we can't read */
166 ret = regmap_read(map, i, &val);
168 snprintf(buf + buf_pos, count - buf_pos,
169 "%.*x", map->debugfs_val_len, val);
171 memset(buf + buf_pos, 'X',
172 map->debugfs_val_len);
173 buf_pos += 2 * map->format.val_bytes;
175 buf[buf_pos++] = '\n';
177 p += map->debugfs_tot_len;
182 if (copy_to_user(user_buf, buf, buf_pos)) {
194 static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
195 size_t count, loff_t *ppos)
197 struct regmap *map = file->private_data;
199 return regmap_read_debugfs(map, 0, map->max_register, user_buf,
203 #undef REGMAP_ALLOW_WRITE_DEBUGFS
204 #ifdef REGMAP_ALLOW_WRITE_DEBUGFS
206 * This can be dangerous especially when we have clients such as
207 * PMICs, therefore don't provide any real compile time configuration option
208 * for this feature, people who want to use this will need to modify
209 * the source code directly.
211 static ssize_t regmap_map_write_file(struct file *file,
212 const char __user *user_buf,
213 size_t count, loff_t *ppos)
218 unsigned long reg, value;
219 struct regmap *map = file->private_data;
221 buf_size = min(count, (sizeof(buf)-1));
222 if (copy_from_user(buf, user_buf, buf_size))
226 while (*start == ' ')
228 reg = simple_strtoul(start, &start, 16);
229 while (*start == ' ')
231 if (strict_strtoul(start, 16, &value))
234 /* Userspace has been fiddling around behind the kernel's back */
235 add_taint(TAINT_USER);
237 regmap_write(map, reg, value);
241 #define regmap_map_write_file NULL
244 static const struct file_operations regmap_map_fops = {
246 .read = regmap_map_read_file,
247 .write = regmap_map_write_file,
248 .llseek = default_llseek,
251 static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf,
252 size_t count, loff_t *ppos)
254 struct regmap_range_node *range = file->private_data;
255 struct regmap *map = range->map;
257 return regmap_read_debugfs(map, range->range_min, range->range_max,
258 user_buf, count, ppos);
261 static const struct file_operations regmap_range_fops = {
263 .read = regmap_range_read_file,
264 .llseek = default_llseek,
267 static ssize_t regmap_access_read_file(struct file *file,
268 char __user *user_buf, size_t count,
271 int reg_len, tot_len;
276 struct regmap *map = file->private_data;
279 if (*ppos < 0 || !count)
282 buf = kmalloc(count, GFP_KERNEL);
286 /* Calculate the length of a fixed format */
287 reg_len = regmap_calc_reg_len(map->max_register, buf, count);
288 tot_len = reg_len + 10; /* ': R W V P\n' */
290 for (i = 0; i <= map->max_register; i += map->reg_stride) {
291 /* Ignore registers which are neither readable nor writable */
292 if (!regmap_readable(map, i) && !regmap_writeable(map, i))
295 /* If we're in the region the user is trying to read */
297 /* ...but not beyond it */
298 if (buf_pos >= count - 1 - tot_len)
301 /* Format the register */
302 snprintf(buf + buf_pos, count - buf_pos,
303 "%.*x: %c %c %c %c\n",
305 regmap_readable(map, i) ? 'y' : 'n',
306 regmap_writeable(map, i) ? 'y' : 'n',
307 regmap_volatile(map, i) ? 'y' : 'n',
308 regmap_precious(map, i) ? 'y' : 'n');
317 if (copy_to_user(user_buf, buf, buf_pos)) {
329 static const struct file_operations regmap_access_fops = {
331 .read = regmap_access_read_file,
332 .llseek = default_llseek,
335 void regmap_debugfs_init(struct regmap *map, const char *name)
337 struct rb_node *next;
338 struct regmap_range_node *range_node;
340 INIT_LIST_HEAD(&map->debugfs_off_cache);
343 map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
344 dev_name(map->dev), name);
345 name = map->debugfs_name;
347 name = dev_name(map->dev);
350 map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
352 dev_warn(map->dev, "Failed to create debugfs directory\n");
356 debugfs_create_file("name", 0400, map->debugfs,
357 map, ®map_name_fops);
359 if (map->max_register) {
360 debugfs_create_file("registers", 0400, map->debugfs,
361 map, ®map_map_fops);
362 debugfs_create_file("access", 0400, map->debugfs,
363 map, ®map_access_fops);
366 if (map->cache_type) {
367 debugfs_create_bool("cache_only", 0400, map->debugfs,
369 debugfs_create_bool("cache_dirty", 0400, map->debugfs,
371 debugfs_create_bool("cache_bypass", 0400, map->debugfs,
375 next = rb_first(&map->range_tree);
377 range_node = rb_entry(next, struct regmap_range_node, node);
379 if (range_node->name)
380 debugfs_create_file(range_node->name, 0400,
381 map->debugfs, range_node,
384 next = rb_next(&range_node->node);
388 void regmap_debugfs_exit(struct regmap *map)
390 struct regmap_debugfs_off_cache *c;
392 debugfs_remove_recursive(map->debugfs);
393 while (!list_empty(&map->debugfs_off_cache)) {
394 c = list_first_entry(&map->debugfs_off_cache,
395 struct regmap_debugfs_off_cache,
400 kfree(map->debugfs_name);
403 void regmap_debugfs_initcall(void)
405 regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
406 if (!regmap_debugfs_root) {
407 pr_warn("regmap: Failed to create debugfs root\n");