linux-toradex.git/drivers/base/regmap/regcache.c, branch v3.2.15

regmap: Fix cache defaults initialization from raw cache defaults

2012-03-01T00:30:52+00:00

commit 61cddc57dc14a5dffa0921d9a24fd68edbb374ac upstream.

Currently registers with a value of 0 are ignored when initializing the register
defaults from raw defaults. This worked in the past, because registers without a
explicit default were assumed to have a default value of 0. This was changed in
commit b03622a8 ("regmap: Ensure rbtree syncs registers set to zero properly").
As a result registers, which have a raw default value of 0 are now assumed to
have no default. This again can result in unnecessary writes when syncing the
cache. It will also result in unnecessary reads for e.g. the first update
operation. In the case where readback is not possible this will even let the
update operation fail, if the register has not been written to before.

So this patch removes the check. Instead it adds a check to ignore raw defaults
for registers which are volatile, since those registers are not cached.

Signed-off-by: Lars-Peter Clausen 
Signed-off-by: Mark Brown 
Signed-off-by: Greg Kroah-Hartman

drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required.

2011-10-31T23:31:38+00:00

Most of these files were implicitly getting EXPORT_SYMBOL via
device.h which was including module.h, but that path will be broken
soon.

[ with input from Stephen Rothwell  ]

Signed-off-by: Paul Gortmaker

regmap: Allow caches for devices with no defaults

2011-10-10T10:55:32+00:00

We only really need the defaults in order to cut down the number of
registers we sync and to satisfy reads while the device is powered off
but not all devices are going to need to do that (always on devices like
PMICs being the prime example) so don't require those devices to supply
a default.  Instead only try to fall back to hardware defaults if the
driver told us to.

Devices using LZO won't be able to instantiate with this, that will require
some updates in the LZO code to handle this case.

Signed-off-by: Mark Brown 
Acked-by: Dimitris Papastamos

regmap: Return a sensible error code if we fail to read the cache

2011-10-10T09:24:03+00:00

If a register isn't cached then let callers know that so they can fall
back or error handle appropriately.

Signed-off-by: Mark Brown 
Acked-by: Dimitris Papastamos

regmap: Use bsearch() to search the register defaults

2011-10-09T11:36:56+00:00

Rather than open coding a binary search use the standard bsearch() using
the comparison function we're already using for sort() on insert. This
fixes a lockup I was observing due to iterating on min <= max rather
than min < max when we fail to look up.

Signed-off-by: Mark Brown 
Acked-by: Dimitris Papastamos

regmap: Fix doc comment

2011-10-03T10:50:53+00:00

Signed-off-by: Dimitris Papastamos 
Signed-off-by: Mark Brown

regmap: Optimize the lookup path to use binary search

2011-10-03T10:50:53+00:00

Since there are more lookups than insertions in a typical
scenario, optimize the linear search into a binary search.  For
this to work, we need to keep reg_defaults sorted upon
insertions, for now be lazy and use sort().

Signed-off-by: Dimitris Papastamos 
Signed-off-by: Mark Brown

regmap: Ensure we scream if we enable cache bypass/only at the same time

2011-09-30T12:57:47+00:00

Signed-off-by: Dimitris Papastamos 
Signed-off-by: Mark Brown

regmap: Implement regcache_cache_bypass helper function

2011-09-30T12:57:47+00:00

Ensure we've got a function so users can enable/disable the
cache bypass option.

Signed-off-by: Dimitris Papastamos 
Signed-off-by: Mark Brown

regmap: Save/restore the bypass state upon syncing

2011-09-30T12:57:47+00:00

Signed-off-by: Dimitris Papastamos 
Signed-off-by: Mark Brown