From e33fabd365596178e72f62bb4b89f0aaad0509ad Mon Sep 17 00:00:00 2001 From: Anthony Olech Date: Fri, 11 Oct 2013 15:31:11 +0100 Subject: 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 Signed-off-by: David Dajun Chen Signed-off-by: Mark Brown --- drivers/base/regmap/regmap.c | 41 +++++++++++++++++++++++++++++++++++++++++ 1 file changed, 41 insertions(+) (limited to 'drivers/base') 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 -- cgit v1.2.3-59-g8ed1b