regmap: new API regmap_multi_reg_write() definition

[~andy/linux] / drivers / base / regmap / regmap.c

diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 7d689a15c500bb34ddc3331f33b57512890341aa..c42ad69e527f186b62609b8a8acff2ae4663c725 100644 (file)
--- a/drivers/base/regmap/regmap.c
+++ b/drivers/base/regmap/regmap.c
@@ -1439,6 +1439,47 @@ out:
 }
 EXPORT_SYMBOL_GPL(regmap_bulk_write);
 
+/*
+ * regmap_multi_reg_write(): Write multiple registers to the device
+ *
+ * where the set of register are supplied in any order
+ *
+ * @map: Register map to write to
+ * @regs: Array of structures containing register,value to be written
+ * @num_regs: Number of registers to write
+ *
+ * This function is intended to be used for writing a large block of data
+ * atomically to the device in single transfer for those I2C client devices
+ * that implement this alternative block write mode.
+ *
+ * A value of zero will be returned on success, a negative errno will
+ * be returned in error cases.
+ */
+int regmap_multi_reg_write(struct regmap *map, struct reg_default *regs,
+                               int num_regs)
+{
+       int ret = 0, i;
+
+       for (i = 0; i < num_regs; i++) {
+               int reg = regs[i].reg;
+               if (reg % map->reg_stride)
+                       return -EINVAL;
+       }
+
+       map->lock(map->lock_arg);
+
+       for (i = 0; i < num_regs; i++) {
+               ret = _regmap_write(map, regs[i].reg, regs[i].def);
+               if (ret != 0)
+                       goto out;
+       }
+out:
+       map->unlock(map->lock_arg);
+
+       return ret;
+}
+EXPORT_SYMBOL_GPL(regmap_multi_reg_write);
+
 /**
  * regmap_raw_write_async(): Write raw values to one or more registers
  *                           asynchronously