regmap: add regmap_update_bits() helper

Add the regmap_update_bits() to simply the read/modify/write of registers
in a single command. The function is taken from Linux regmap
implementation.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

diff --git a/drivers/core/regmap.c b/drivers/core/regmap.c
index fabcc5f53a838fb7bf1bc2a86f7cadfb0763e6e9..8e5c3bcf61bbc4927b2ccf577df927bafba1efb6 100644 (file)
--- a/drivers/core/regmap.c
+++ b/drivers/core/regmap.c
@@ -132,3 +132,17 @@ int regmap_write(struct regmap *map, uint offset, uint val)
 
        return 0;
 }
+
+int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val)
+{
+       uint reg;
+       int ret;
+
+       ret = regmap_read(map, offset, &reg);
+       if (ret)
+               return ret;
+
+       reg &= ~mask;
+
+       return regmap_write(map, offset, reg | val);
+}

diff --git a/include/regmap.h b/include/regmap.h
index e96c79dd26a219843d6343fb7d789aa63ae1cad5..6a574eaa41294a740a688f3bc717c0ba68afcf8f 100644 (file)
--- a/include/regmap.h
+++ b/include/regmap.h
@@ -42,6 +42,16 @@ int regmap_read(struct regmap *map, uint offset, uint *valp);
 #define regmap_read32(map, ptr, member, valp) \
        regmap_read(map, (uint32_t *)(ptr)->member - (uint32_t *)(ptr), valp)
 
+/**
+ * regmap_update_bits() - Perform a read/modify/write using a mask
+ *
+ * @map:       The map returned by regmap_init_mem*()
+ * @offset:    Offset of the memory
+ * @mask:      Mask to apply to the read value
+ * @val:       Value to apply to the value to write
+ */
+int regmap_update_bits(struct regmap *map, uint offset, uint mask, uint val);
+
 /**
  * regmap_init_mem() - Set up a new register map that uses memory access
  *