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author | Anthony Olech <anthony.olech.opensource@diasemi.com> | 2013-10-11 14:31:11 (GMT) |
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committer | Mark Brown <broonie@linaro.org> | 2013-10-14 14:09:16 (GMT) |
commit | e33fabd365596178e72f62bb4b89f0aaad0509ad (patch) | |
tree | 6c0aad1f15bc40d0596cd4678658ad51022029fc /drivers/base/regmap | |
parent | 61e6cfa80de5760bbe406f4e815b7739205754d2 (diff) | |
download | linux-e33fabd365596178e72f62bb4b89f0aaad0509ad.tar.xz |
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')
-rw-r--r-- | drivers/base/regmap/regmap.c | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index 7d689a1..c42ad69 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 |