tree b28c4098a5b75a34efd8262efcc99fdf8d586365
parent afab2f7b21b042bcbffb1e82f78243382a122d70
author Mark Brown <broonie@opensource.wolfsonmicro.com> 1355156669 +0900
committer Mark Brown <broonie@opensource.wolfsonmicro.com> 1355156987 +0900

regmap: debugfs: Cache offsets of valid regions for dump

Avoid doing a linear scan of the entire register map for each read() of
the debugfs register dump by recording the offsets where valid registers
exist when we first read the registers file. This assumes the set of
valid registers never changes, if this is not the case invalidation of
the cache will be required.

This could be further improved for large blocks of contiguous registers
by calculating the register we will read from within the block - currently
we do a linear scan of the block. An rbtree may also be worthwhile.

Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>