Some device drivers using the register map API need to copy the
value from one register to another. Even though it can be done
with a combination of regmap_read() and regmap_write(), it is
better to have a function to avoid code duplication, sanity check
passed values and do it atomically by holding the regmap lock.
Signed-off-by: Javier Martinez Canillas <javier.martinez@xxxxxxxxxxxxxxx>
---
drivers/base/regmap/regmap.c | 34 ++++++++++++++++++++++++++++++++++
include/linux/regmap.h | 9 +++++++++
2 files changed, 43 insertions(+)
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 74d8c06..a2e0b04 100644
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -2555,6 +2555,40 @@ int regmap_parse_val(struct regmap *map, const void *buf,
}
EXPORT_SYMBOL_GPL(regmap_parse_val);
+/**
+ * regmap_reg_copy(): Copy a value from a single register to another one
+ *
+ * @map: Register map to operate on
+ * @dest: Register to copy the value to
+ * @src: Register to copy the value from
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_reg_copy(struct regmap *map, unsigned int dest, unsigned int src)
+{
+ int val;
+ int ret = 0;
+
+ if (dest == src)
+ return ret;
+
+ if (dest % map->reg_stride ||
+ src % map->reg_stride)
+ return -EINVAL;
+
+ map->lock(map->lock_arg);
+
+ ret = _regmap_read(map, src, &val);
+ if (!ret)
+ ret = _regmap_write(map, dest, val);
+
+ map->unlock(map->lock_arg);
+
+ return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_reg_copy);
+
static int __init regmap_initcall(void)
{
regmap_debugfs_initcall();
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index 7b0e4b4..116c22b 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -445,6 +445,8 @@ int regmap_register_patch(struct regmap *map, const struct reg_default *regs,
int regmap_parse_val(struct regmap *map, const void *buf,
unsigned int *val);
+int regmap_reg_copy(struct regmap *map, unsigned int dest, unsigned int src);
+
static inline bool regmap_reg_in_range(unsigned int reg,
const struct regmap_range *range)
{
@@ -723,6 +725,13 @@ static inline int regmap_parse_val(struct regmap *map, const void *buf,
return -EINVAL;
}
+static inline int regmap_reg_copy(struct regmap *map, unsigned int dest,
+ unsigned int src)
+{
+ WARN_ONCE(1, "regmap API is disabled");
+ return -EINVAL;
+}
+
static inline struct regmap *dev_get_regmap(struct device *dev,
const char *name)
{
--
2.0.0.rc2
--
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