regmap: Support reading from specific range

It is useful to be able to treat the different ranges of a regmap
separately to be able to use distinct offset for them, but this is
currently not implemented in the regmap API.

To preserve backwards compatibility, add regmap_read_range and
regmap_write_range functions that take an additional parameter
'range_num' that identifies the range to operate on.

Reviewed-by: Anatolij Gustschin <agust@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Mario Six <mario.six@gdsys.cc>

drivers/core/regmap.c

@@ -188,11 +188,25 @@ int regmap_uninit(struct regmap *map)
 	return 0;
 }
 
-int regmap_raw_read(struct regmap *map, uint offset, void *valp, size_t val_len)
+int regmap_raw_read_range(struct regmap *map, uint range_num, uint offset,
+			  void *valp, size_t val_len)
 {
+	struct regmap_range *range;
 	void *ptr;
 
-	ptr = map_physmem(map->ranges[0].start + offset, val_len, MAP_NOCACHE);
+	if (range_num >= map->range_count) {
+		debug("%s: range index %d larger than range count\n",
+		      __func__, range_num);
+		return -ERANGE;
+	}
+	range = &map->ranges[range_num];
+
+	ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
+
+	if (offset + val_len > range->size) {
+		debug("%s: offset/size combination invalid\n", __func__);
+		return -ERANGE;
+	}
 
 	switch (val_len) {
 	case REGMAP_SIZE_8:
@@ -213,20 +227,39 @@ int regmap_raw_read(struct regmap *map, uint offset, void *valp, size_t val_len)
 		debug("%s: regmap size %zu unknown\n", __func__, val_len);
 		return -EINVAL;
 	}
+
 	return 0;
 }
 
+int regmap_raw_read(struct regmap *map, uint offset, void *valp, size_t val_len)
+{
+	return regmap_raw_read_range(map, 0, offset, valp, val_len);
+}
+
 int regmap_read(struct regmap *map, uint offset, uint *valp)
 {
 	return regmap_raw_read(map, offset, valp, REGMAP_SIZE_32);
 }
 
-int regmap_raw_write(struct regmap *map, uint offset, const void *val,
-		     size_t val_len)
+int regmap_raw_write_range(struct regmap *map, uint range_num, uint offset,
+			   const void *val, size_t val_len)
 {
+	struct regmap_range *range;
 	void *ptr;
 
-	ptr = map_physmem(map->ranges[0].start + offset, val_len, MAP_NOCACHE);
+	if (range_num >= map->range_count) {
+		debug("%s: range index %d larger than range count\n",
+		      __func__, range_num);
+		return -ERANGE;
+	}
+	range = &map->ranges[range_num];
+
+	ptr = map_physmem(range->start + offset, val_len, MAP_NOCACHE);
+
+	if (offset + val_len > range->size) {
+		debug("%s: offset/size combination invalid\n", __func__);
+		return -ERANGE;
+	}
 
 	switch (val_len) {
 	case REGMAP_SIZE_8:
@@ -251,6 +284,12 @@ int regmap_raw_write(struct regmap *map, uint offset, const void *val,
 	return 0;
 }
 
+int regmap_raw_write(struct regmap *map, uint offset, const void *val,
+		     size_t val_len)
+{
+	return regmap_raw_write_range(map, 0, offset, val, val_len);
+}
+
 int regmap_write(struct regmap *map, uint offset, uint val)
 {
 	return regmap_raw_write(map, offset, &val, REGMAP_SIZE_32);

include/regmap.h

@@ -115,6 +115,37 @@ int regmap_raw_write(struct regmap *map, uint offset, const void *val,
 int regmap_raw_read(struct regmap *map, uint offset, void *valp,
 		    size_t val_len);
 
+/**
+ * regmap_raw_write_range() - Write a value of specified length to a range of a
+ *			      regmap
+ *
+ * @map:	Regmap to write to
+ * @range_num:	Number of the range in the regmap to write to
+ * @offset:	Offset in the regmap to write to
+ * @val:	Value to write to the regmap at the specified offset
+ * @val_len:	Length of the data to be written to the regmap
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int regmap_raw_write_range(struct regmap *map, uint range_num, uint offset,
+			   const void *val, size_t val_len);
+
+/**
+ * regmap_raw_read_range() - Read a value of specified length from a range of a
+ *			     regmap
+ *
+ * @map:	Regmap to read from
+ * @range_num:	Number of the range in the regmap to write to
+ * @offset:	Offset in the regmap to read from
+ * @valp:	Pointer to the buffer to receive the data read from the regmap
+ *		at the specified offset
+ * @val_len:	Length of the data to be read from the regmap
+ *
+ * Return: 0 if OK, -ve on error
+ */
+int regmap_raw_read_range(struct regmap *map, uint range_num, uint offset,
+			  void *valp, size_t val_len);
+
 #define regmap_write32(map, ptr, member, val) \
 	regmap_write(map, (uint32_t *)(ptr)->member - (uint32_t *)(ptr), val)