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authorAnthony Olech <anthony.olech.opensource@diasemi.com>2013-10-11 15:31:11 +0100
committerMark Brown <broonie@linaro.org>2013-10-14 15:09:16 +0100
commite33fabd365596178e72f62bb4b89f0aaad0509ad (patch)
tree6c0aad1f15bc40d0596cd4678658ad51022029fc /drivers/base/regmap/regmap.c
parent61e6cfa80de5760bbe406f4e815b7739205754d2 (diff)
downloadlinux-linaro-stable-e33fabd365596178e72f62bb4b89f0aaad0509ad.tar.gz
regmap: new API regmap_multi_reg_write() definition
New API regmap_multi_reg_write() is defined that allows a set of reg,val pairs to be written to a I2C client device as one block transfer from the point of view of a single I2C master system. A simple demonstration implementation is included that just splits the block write request into a sequence of single register writes. The implementation will be modified later to support those I2C clients that implement the alternative non-standard MULTIWRITE block write mode so to achieve a single I2C transfer that will be atomic even in multiple I2C master systems. Signed-off-by: Anthony Olech <anthony.olech.opensource@diasemi.com> Signed-off-by: David Dajun Chen <david.chen@diasemi.com> Signed-off-by: Mark Brown <broonie@linaro.org>
Diffstat (limited to 'drivers/base/regmap/regmap.c')
-rw-r--r--drivers/base/regmap/regmap.c41
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c
index 7d689a15c500..c42ad69e527f 100644
--- 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