Pileus Git - ~andy/linux/blob - 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 ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
  60                                    unsigned int to, char __user *user_buf,
  61                                    size_t count, loff_t *ppos)
  62 {
  63         int reg_len, val_len, tot_len;
  64         size_t buf_pos = 0;
  65         loff_t p = 0;
  66         ssize_t ret;
  67         int i;
  68         char *buf;
  69         unsigned int val;
  70
  71         if (*ppos < 0 || !count)
  72                 return -EINVAL;
  73
  74         buf = kmalloc(count, GFP_KERNEL);
  75         if (!buf)
  76                 return -ENOMEM;
  77
  78         /* Calculate the length of a fixed format  */
  79         reg_len = regmap_calc_reg_len(map->max_register, buf, count);
  80         val_len = 2 * map->format.val_bytes;
  81         tot_len = reg_len + val_len + 3;      /* : \n */
  82
  83         for (i = from; i <= to; i += map->reg_stride) {
  84                 if (!regmap_readable(map, i))
  85                         continue;
  86
  87                 if (regmap_precious(map, i))
  88                         continue;
  89
  90                 /* If we're in the region the user is trying to read */
  91                 if (p >= *ppos) {
  92                         /* ...but not beyond it */
  93                         if (buf_pos >= count - 1 - tot_len)
  94                                 break;
  95
  96                         /* Format the register */
  97                         snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
  98                                  reg_len, i - from);
  99                         buf_pos += reg_len + 2;
 100
 101                         /* Format the value, write all X if we can't read */
 102                         ret = regmap_read(map, i, &val);
 103                         if (ret == 0)
 104                                 snprintf(buf + buf_pos, count - buf_pos,
 105                                          "%.*x", val_len, val);
 106                         else
 107                                 memset(buf + buf_pos, 'X', val_len);
 108                         buf_pos += 2 * map->format.val_bytes;
 109
 110                         buf[buf_pos++] = '\n';
 111                 }
 112                 p += tot_len;
 113         }
 114
 115         ret = buf_pos;
 116
 117         if (copy_to_user(user_buf, buf, buf_pos)) {
 118                 ret = -EFAULT;
 119                 goto out;
 120         }
 121
 122         *ppos += buf_pos;
 123
 124 out:
 125         kfree(buf);
 126         return ret;
 127 }
 128
 129 static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
 130                                     size_t count, loff_t *ppos)
 131 {
 132         struct regmap *map = file->private_data;
 133
 134         return regmap_read_debugfs(map, 0, map->max_register, user_buf,
 135                                    count, ppos);
 136 }
 137
 138 #undef REGMAP_ALLOW_WRITE_DEBUGFS
 139 #ifdef REGMAP_ALLOW_WRITE_DEBUGFS
 140 /*
 141  * This can be dangerous especially when we have clients such as
 142  * PMICs, therefore don't provide any real compile time configuration option
 143  * for this feature, people who want to use this will need to modify
 144  * the source code directly.
 145  */
 146 static ssize_t regmap_map_write_file(struct file *file,
 147                                      const char __user *user_buf,
 148                                      size_t count, loff_t *ppos)
 149 {
 150         char buf[32];
 151         size_t buf_size;
 152         char *start = buf;
 153         unsigned long reg, value;
 154         struct regmap *map = file->private_data;
 155
 156         buf_size = min(count, (sizeof(buf)-1));
 157         if (copy_from_user(buf, user_buf, buf_size))
 158                 return -EFAULT;
 159         buf[buf_size] = 0;
 160
 161         while (*start == ' ')
 162                 start++;
 163         reg = simple_strtoul(start, &start, 16);
 164         while (*start == ' ')
 165                 start++;
 166         if (strict_strtoul(start, 16, &value))
 167                 return -EINVAL;
 168
 169         /* Userspace has been fiddling around behind the kernel's back */
 170         add_taint(TAINT_USER);
 171
 172         regmap_write(map, reg, value);
 173         return buf_size;
 174 }
 175 #else
 176 #define regmap_map_write_file NULL
 177 #endif
 178
 179 static const struct file_operations regmap_map_fops = {
 180         .open = simple_open,
 181         .read = regmap_map_read_file,
 182         .write = regmap_map_write_file,
 183         .llseek = default_llseek,
 184 };
 185
 186 static ssize_t regmap_range_read_file(struct file *file, char __user *user_buf,
 187                                       size_t count, loff_t *ppos)
 188 {
 189         struct regmap_range_node *range = file->private_data;
 190         struct regmap *map = range->map;
 191
 192         return regmap_read_debugfs(map, range->range_min, range->range_max,
 193                                    user_buf, count, ppos);
 194 }
 195
 196 static const struct file_operations regmap_range_fops = {
 197         .open = simple_open,
 198         .read = regmap_range_read_file,
 199         .llseek = default_llseek,
 200 };
 201
 202 static ssize_t regmap_access_read_file(struct file *file,
 203                                        char __user *user_buf, size_t count,
 204                                        loff_t *ppos)
 205 {
 206         int reg_len, tot_len;
 207         size_t buf_pos = 0;
 208         loff_t p = 0;
 209         ssize_t ret;
 210         int i;
 211         struct regmap *map = file->private_data;
 212         char *buf;
 213
 214         if (*ppos < 0 || !count)
 215                 return -EINVAL;
 216
 217         buf = kmalloc(count, GFP_KERNEL);
 218         if (!buf)
 219                 return -ENOMEM;
 220
 221         /* Calculate the length of a fixed format  */
 222         reg_len = regmap_calc_reg_len(map->max_register, buf, count);
 223         tot_len = reg_len + 10; /* ': R W V P\n' */
 224
 225         for (i = 0; i <= map->max_register; i += map->reg_stride) {
 226                 /* Ignore registers which are neither readable nor writable */
 227                 if (!regmap_readable(map, i) && !regmap_writeable(map, i))
 228                         continue;
 229
 230                 /* If we're in the region the user is trying to read */
 231                 if (p >= *ppos) {
 232                         /* ...but not beyond it */
 233                         if (buf_pos >= count - 1 - tot_len)
 234                                 break;
 235
 236                         /* Format the register */
 237                         snprintf(buf + buf_pos, count - buf_pos,
 238                                  "%.*x: %c %c %c %c\n",
 239                                  reg_len, i,
 240                                  regmap_readable(map, i) ? 'y' : 'n',
 241                                  regmap_writeable(map, i) ? 'y' : 'n',
 242                                  regmap_volatile(map, i) ? 'y' : 'n',
 243                                  regmap_precious(map, i) ? 'y' : 'n');
 244
 245                         buf_pos += tot_len;
 246                 }
 247                 p += tot_len;
 248         }
 249
 250         ret = buf_pos;
 251
 252         if (copy_to_user(user_buf, buf, buf_pos)) {
 253                 ret = -EFAULT;
 254                 goto out;
 255         }
 256
 257         *ppos += buf_pos;
 258
 259 out:
 260         kfree(buf);
 261         return ret;
 262 }
 263
 264 static const struct file_operations regmap_access_fops = {
 265         .open = simple_open,
 266         .read = regmap_access_read_file,
 267         .llseek = default_llseek,
 268 };
 269
 270 void regmap_debugfs_init(struct regmap *map, const char *name)
 271 {
 272         struct rb_node *next;
 273         struct regmap_range_node *range_node;
 274
 275         if (name) {
 276                 map->debugfs_name = kasprintf(GFP_KERNEL, "%s-%s",
 277                                               dev_name(map->dev), name);
 278                 name = map->debugfs_name;
 279         } else {
 280                 name = dev_name(map->dev);
 281         }
 282
 283         map->debugfs = debugfs_create_dir(name, regmap_debugfs_root);
 284         if (!map->debugfs) {
 285                 dev_warn(map->dev, "Failed to create debugfs directory\n");
 286                 return;
 287         }
 288
 289         debugfs_create_file("name", 0400, map->debugfs,
 290                             map, &regmap_name_fops);
 291
 292         if (map->max_register) {
 293                 debugfs_create_file("registers", 0400, map->debugfs,
 294                                     map, &regmap_map_fops);
 295                 debugfs_create_file("access", 0400, map->debugfs,
 296                                     map, &regmap_access_fops);
 297         }
 298
 299         if (map->cache_type) {
 300                 debugfs_create_bool("cache_only", 0400, map->debugfs,
 301                                     &map->cache_only);
 302                 debugfs_create_bool("cache_dirty", 0400, map->debugfs,
 303                                     &map->cache_dirty);
 304                 debugfs_create_bool("cache_bypass", 0400, map->debugfs,
 305                                     &map->cache_bypass);
 306         }
 307
 308         next = rb_first(&map->range_tree);
 309         while (next) {
 310                 range_node = rb_entry(next, struct regmap_range_node, node);
 311
 312                 if (range_node->name)
 313                         debugfs_create_file(range_node->name, 0400,
 314                                             map->debugfs, range_node,
 315                                             &regmap_range_fops);
 316
 317                 next = rb_next(&range_node->node);
 318         }
 319 }
 320
 321 void regmap_debugfs_exit(struct regmap *map)
 322 {
 323         debugfs_remove_recursive(map->debugfs);
 324         kfree(map->debugfs_name);
 325 }
 326
 327 void regmap_debugfs_initcall(void)
 328 {
 329         regmap_debugfs_root = debugfs_create_dir("regmap", NULL);
 330         if (!regmap_debugfs_root) {
 331                 pr_warn("regmap: Failed to create debugfs root\n");
 332                 return;
 333         }
 334 }