regmap: Factor out debugfs register read

This will allow the use of the same code for reading register ranges.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

drivers/base/regmap/regmap-debugfs.c

@@ -56,15 +56,15 @@ static const struct file_operations regmap_name_fops = {
 	.llseek = default_llseek,
 };
 
-static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
-				    size_t count, loff_t *ppos)
+static ssize_t regmap_read_debugfs(struct regmap *map, unsigned int from,
+				   unsigned int to, char __user *user_buf,
+				   size_t count, loff_t *ppos)
 {
 	int reg_len, val_len, tot_len;
 	size_t buf_pos = 0;
 	loff_t p = 0;
 	ssize_t ret;
 	int i;
-	struct regmap *map = file->private_data;
 	char *buf;
 	unsigned int val;
 
@@ -80,7 +80,7 @@ static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
 	val_len = 2 * map->format.val_bytes;
 	tot_len = reg_len + val_len + 3;      /* : \n */
 
-	for (i = 0; i <= map->max_register; i += map->reg_stride) {
+	for (i = from; i <= to; i += map->reg_stride) {
 		if (!regmap_readable(map, i))
 			continue;
 
@@ -95,7 +95,7 @@ static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
 
 			/* Format the register */
 			snprintf(buf + buf_pos, count - buf_pos, "%.*x: ",
-				 reg_len, i);
+				 reg_len, i - from);
 			buf_pos += reg_len + 2;
 
 			/* Format the value, write all X if we can't read */
@@ -126,6 +126,15 @@ static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
 	return ret;
 }
 
+static ssize_t regmap_map_read_file(struct file *file, char __user *user_buf,
+				    size_t count, loff_t *ppos)
+{
+	struct regmap *map = file->private_data;
+
+	return regmap_read_debugfs(map, 0, map->max_register, user_buf,
+				   count, ppos);
+}
+
 #undef REGMAP_ALLOW_WRITE_DEBUGFS
 #ifdef REGMAP_ALLOW_WRITE_DEBUGFS
 /*