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author | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-11-29 20:10:36 (GMT) |
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committer | Mark Brown <broonie@opensource.wolfsonmicro.com> | 2011-11-29 20:15:50 (GMT) |
commit | 018690d33ecf4aa1eb1415e38c40e2b0b6c7808e (patch) | |
tree | 3ae08fb9d199813840564fb392ebc9b4a5d8c230 /drivers/base/regmap | |
parent | c86845dc7b56be050b9e53b31079e8bd0a3dc279 (diff) | |
download | linux-018690d33ecf4aa1eb1415e38c40e2b0b6c7808e.tar.xz |
regmap: Allow regmap_update_bits() users to detect changes
Some users of regmap_update_bits() would like to be able to tell their
users if they actually did an update so provide a variant which also
returns a flag indicating if an update took place. We could return a
tristate in the return value of regmap_update_bits() but this makes the
API more cumbersome to use and doesn't fit with the general zero for
success idiom we have.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Diffstat (limited to 'drivers/base/regmap')
-rw-r--r-- | drivers/base/regmap/regmap.c | 58 |
1 files changed, 45 insertions, 13 deletions
diff --git a/drivers/base/regmap/regmap.c b/drivers/base/regmap/regmap.c index a862090..add5da6 100644 --- a/drivers/base/regmap/regmap.c +++ b/drivers/base/regmap/regmap.c @@ -569,18 +569,9 @@ int regmap_bulk_read(struct regmap *map, unsigned int reg, void *val, } EXPORT_SYMBOL_GPL(regmap_bulk_read); -/** - * regmap_update_bits: Perform a read/modify/write cycle on the register map - * - * @map: Register map to update - * @reg: Register to update - * @mask: Bitmask to change - * @val: New value for bitmask - * - * Returns zero for success, a negative number on error. - */ -int regmap_update_bits(struct regmap *map, unsigned int reg, - unsigned int mask, unsigned int val) +static int _regmap_update_bits(struct regmap *map, unsigned int reg, + unsigned int mask, unsigned int val, + bool *change) { int ret; unsigned int tmp, orig; @@ -594,16 +585,57 @@ int regmap_update_bits(struct regmap *map, unsigned int reg, tmp = orig & ~mask; tmp |= val & mask; - if (tmp != orig) + if (tmp != orig) { ret = _regmap_write(map, reg, tmp); + *change = true; + } else { + *change = false; + } out: mutex_unlock(&map->lock); return ret; } + +/** + * regmap_update_bits: Perform a read/modify/write cycle on the register map + * + * @map: Register map to update + * @reg: Register to update + * @mask: Bitmask to change + * @val: New value for bitmask + * + * Returns zero for success, a negative number on error. + */ +int regmap_update_bits(struct regmap *map, unsigned int reg, + unsigned int mask, unsigned int val) +{ + bool change; + return _regmap_update_bits(map, reg, mask, val, &change); +} EXPORT_SYMBOL_GPL(regmap_update_bits); +/** + * regmap_update_bits_check: Perform a read/modify/write cycle on the + * register map and report if updated + * + * @map: Register map to update + * @reg: Register to update + * @mask: Bitmask to change + * @val: New value for bitmask + * @change: Boolean indicating if a write was done + * + * Returns zero for success, a negative number on error. + */ +int regmap_update_bits_check(struct regmap *map, unsigned int reg, + unsigned int mask, unsigned int val, + bool *change) +{ + return _regmap_update_bits(map, reg, mask, val, change); +} +EXPORT_SYMBOL_GPL(regmap_update_bits_check); + static int __init regmap_initcall(void) { regmap_debugfs_initcall(); |