regmap: Allow specifying read/write width

Right now, regmap_read() and regmap_write() read/write a 32-bit value
only. To write other lengths, regmap_raw_read() and regmap_raw_write()
need to be used.

This means that any driver ported from Linux that relies on
regmap_{read,write}() to know the size already has to be updated at each
callsite. This makes the port harder to maintain.

So, allow specifying the read/write width to make it easier to port the
drivers, since now the only change needed is when initializing the
regmap.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 34 insertions, 19 deletions

diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
index 809f58489f..c71b961234 100644
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -25,6 +25,10 @@ DECLARE_GLOBAL_DATA_PTR;
  * regmap_alloc() - Allocate a regmap with a given number of ranges.
  *
  * @count: Number of ranges to be allocated for the regmap.
+ *
+ * The default regmap width is set to REGMAP_SIZE_32. Callers can override it
+ * if they need.
+ *
  * Return: A pointer to the newly allocated regmap, or NULL on error.
  */
 static struct regmap *regmap_alloc(int count)
@@ -36,6 +40,7 @@ static struct regmap *regmap_alloc(int count)
 	if (!map)
 		return NULL;
 	map->range_count = count;
+	map->width = REGMAP_SIZE_32;
 
 	return map;
 }
@@ -244,7 +249,7 @@ struct regmap *devm_regmap_init(struct udevice *dev,
 				const struct regmap_config *config)
 {
 	int rc;
-	struct regmap **mapp;
+	struct regmap **mapp, *map;
 
 	mapp = devres_alloc(devm_regmap_release, sizeof(struct regmap *),
 			    __GFP_ZERO);
@@ -255,6 +260,10 @@ struct regmap *devm_regmap_init(struct udevice *dev,
 	if (rc)
 		return ERR_PTR(rc);
 
+	map = *mapp;
+	if (config)
+		map->width = config->width;
+
 	devres_add(dev, mapp);
 	return *mapp;
 }
@@ -377,7 +386,7 @@ int regmap_raw_read(struct regmap *map, uint offset, void *valp, size_t val_len)
 
 int regmap_read(struct regmap *map, uint offset, uint *valp)
 {
-	return regmap_raw_read(map, offset, valp, REGMAP_SIZE_32);
+	return regmap_raw_read(map, offset, valp, map->width);
 }
 
 static inline void __write_8(u8 *addr, const u8 *val,
@@ -487,7 +496,7 @@ int regmap_raw_write(struct regmap *map, uint offset, const void *val,
 
 int regmap_write(struct regmap *map, uint offset, uint val)
 {
-	return regmap_raw_write(map, offset, &val, REGMAP_SIZE_32);
+	return regmap_raw_write(map, offset, &val, map->width);
 }
 
 int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val)
diff --git a/include/regmap.h b/include/regmap.h
index c7dd240a74..19474e6de1 100644
--- a/include/regmap.h
+++ b/include/regmap.h
@@ -76,16 +76,28 @@ struct regmap_range {
 };
 
 struct regmap_bus;
-struct regmap_config;
+
+/**
+ * struct regmap_config - Configure the behaviour of a regmap
+ *
+ * @width:		Width of the read/write operations. Defaults to
+ *			REGMAP_SIZE_32 if set to 0.
+ */
+struct regmap_config {
+	enum regmap_size_t width;
+};
 
 /**
  * struct regmap - a way of accessing hardware/bus registers
  *
+ * @width:		Width of the read/write operations. Defaults to
+ *			REGMAP_SIZE_32 if set to 0.
  * @range_count:	Number of ranges available within the map
  * @ranges:		Array of ranges
  */
 struct regmap {
 	enum regmap_endianness_t endianness;
+	enum regmap_size_t width;
 	int range_count;
 	struct regmap_range ranges[0];
 };
@@ -96,32 +108,24 @@ struct regmap {
  */
 
 /**
- * regmap_write() - Write a 32-bit value to a regmap
+ * regmap_write() - Write a value to a regmap
  *
  * @map:	Regmap to write to
  * @offset:	Offset in the regmap to write to
  * @val:	Data to write to the regmap at the specified offset
  *
- * Note that this function will only write values of 32 bit width to the
- * regmap; if the size of data to be read is different, the regmap_raw_write
- * function can be used.
- *
  * Return: 0 if OK, -ve on error
  */
 int regmap_write(struct regmap *map, uint offset, uint val);
 
 /**
- * regmap_read() - Read a 32-bit value from a regmap
+ * regmap_read() - Read a value from a regmap
  *
  * @map:	Regmap to read from
  * @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
  *
- * Note that this function will only read values of 32 bit width from the
- * regmap; if the size of data to be read is different, the regmap_raw_read
- * function can be used.
- *
  * Return: 0 if OK, -ve on error
  */
 int regmap_read(struct regmap *map, uint offset, uint *valp);
@@ -135,8 +139,9 @@ int regmap_read(struct regmap *map, uint offset, uint *valp);
  * @val_len:	Length of the data to be written to the regmap
  *
  * Note that this function will, as opposed to regmap_write, write data of
- * arbitrary length to the regmap, and not just 32-bit values, and is thus a
- * generalized version of regmap_write.
+ * arbitrary length to the regmap, and not just the size configured in the
+ * regmap (defaults to 32-bit) and is thus a generalized version of
+ * regmap_write.
  *
  * Return: 0 if OK, -ve on error
  */
@@ -153,8 +158,9 @@ int regmap_raw_write(struct regmap *map, uint offset, const void *val,
  * @val_len:	Length of the data to be read from the regmap
  *
  * Note that this function will, as opposed to regmap_read, read data of
- * arbitrary length from the regmap, and not just 32-bit values, and is thus a
- * generalized version of regmap_read.
+ * arbitrary length from the regmap, and not just the size configured in the
+ * regmap (defaults to 32-bit) and is thus a generalized version of
+ * regmap_read.
  *
  * Return: 0 if OK, -ve on error
  */
@@ -344,7 +350,7 @@ int regmap_init_mem_index(ofnode node, struct regmap **mapp, int index);
  * @dev: Device that will be interacted with
  * @bus: Bus-specific callbacks to use with device (IGNORED)
  * @bus_context: Data passed to bus-specific callbacks (IGNORED)
- * @config: Configuration for register map (IGNORED)
+ * @config: Configuration for register map
  *
  * @Return a valid pointer to a struct regmap or a ERR_PTR() on error.
  * The structure is automatically freed when the device is unbound