diff options
| -rw-r--r-- | drivers/base/regmap/regmap-debugfs.c | 42 |
1 files changed, 42 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap-debugfs.c b/drivers/base/regmap/regmap-debugfs.c index b3b4b8f7f409..7accb81dd94e 100644 --- a/drivers/base/regmap/regmap-debugfs.c +++ b/drivers/base/regmap/regmap-debugfs.c @@ -103,9 +103,51 @@ out: return ret; } +#undef REGMAP_ALLOW_WRITE_DEBUGFS +#ifdef REGMAP_ALLOW_WRITE_DEBUGFS +/* + * This can be dangerous especially when we have clients such as + * PMICs, therefore don't provide any real compile time configuration option + * for this feature, people who want to use this will need to modify + * the source code directly. + */ +static ssize_t regmap_map_write_file(struct file *file, + const char __user *user_buf, + size_t count, loff_t *ppos) +{ + char buf[32]; + size_t buf_size; + char *start = buf; + unsigned long reg, value; + struct regmap *map = file->private_data; + + buf_size = min(count, (sizeof(buf)-1)); + if (copy_from_user(buf, user_buf, buf_size)) + return -EFAULT; + buf[buf_size] = 0; + + while (*start == ' ') + start++; + reg = simple_strtoul(start, &start, 16); + while (*start == ' ') + start++; + if (strict_strtoul(start, 16, &value)) + return -EINVAL; + + /* Userspace has been fiddling around behind the kernel's back */ + add_taint(TAINT_USER); + + regmap_write(map, reg, value); + return buf_size; +} +#else +#define regmap_map_write_file NULL +#endif + static const struct file_operations regmap_map_fops = { .open = regmap_open_file, .read = regmap_map_read_file, + .write = regmap_map_write_file, .llseek = default_llseek, }; |