| e466de05194b666114713b753e2f4be1d4200140 |
|
03-Apr-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Export regcache_sync_region()
regcache_sync_region() isn't going to be useful to most drivers if we
don't export it since otherwise they can't use it when built modular.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 51990e825431089747f8896244b5c17d3a6423f1 |
|
22-Jan-2012 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
device.h: cleanup users outside of linux/include (C files)
For files that are actively using linux/device.h, make sure
that they call it out. This will allow us to clean up some
of the implicit uses of linux/device.h within include/*
without introducing build regressions.
Yes, this was created by "cheating" -- i.e. the headers were
cleaned up, and then the fallout was found and fixed, and then
the two commits were reordered. This ensures we don't introduce
build regressions into the git history.
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
|
| 4d4cfd1656b5f6c88eae51c40741a695b108b006 |
|
23-Feb-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Allow drivers to sync only part of the register cache
Provide a regcache_sync_region() operation which allows drivers to
write only part of the cache back to the hardware. This is intended
for use in cases like power domains or DSP memories where part of the
device register map may be reset without fully resetting the device.
Fully supporting these devices is likely to require additional work to
make specific regions of the register map cache only while they are in
reset, but this is enough for most devices.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| ac8d91c801905a061ca883dca427a5e19602a1e7 |
|
23-Feb-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Supply ranges to the sync operations
In order to allow us to support partial sync operations add minimum and
maximum register arguments to the sync operation and update the rbtree
and lzo caches to use this new information. The LZO implementation is
obviously not good, we could exit the iteration earlier, but there may
be room for more wide reaching optimisation there.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 5d5b7d4f80ed6e861c1c220fd57e3dad0912526e |
|
23-Feb-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Add tracepoints for cache only and cache bypass
Useful for figuring out where the hardware interaction went or came from.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 6ff7373809a9b4eb644d83e2e299da297e1cbffa |
|
23-Feb-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Mark the cache as clean after a successful sync
Previously the cache would never be marked clean, meaning syncs would
never be suppressed which isn't the end of the world but could be
inefficient.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| c3ec23288a92e20e0aff84a4cb6fbc7cc9bcf567 |
|
23-Feb-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Remove default cache sync implementation
It's not used as all cache types have sync operations so it's just dead
code which never gets tested.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 7d5e525b9ceda0e3b85da0acdaa2de19fea51edc |
|
18-Feb-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Implement support for 32 bit registers and values
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| df00c79f78d8b0ad788daf689ea461ace9d0811f |
|
17-Feb-2012 |
Laxman Dewangan <ldewangan@nvidia.com> |
regmap: Bypassing cache when initializing cache
During regcache_init, if client has not passed the
default data of cached register then it is directly
read from the hw to initialize cache. This hw register
read happens before cache ops are initialized and hence
avoiding register read to check for the data available
on cache or not by enabling flag of cache_bypass.
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 61cddc57dc14a5dffa0921d9a24fd68edbb374ac |
|
15-Feb-2012 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Fix cache defaults initialization from raw cache defaults
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 <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org
|
| aa795d129246cb4c973076e3242b8a2eb374f1ef |
|
31-Jan-2012 |
Axel Lin <axel.lin@gmail.com> |
regmap: Remove incorrect unreachable comment in regcache_set_val()
regcache_set_val() returns false if cache[idx] != val.
Thus it actually is not unreachable.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 8a892d6996b60c822f19ad1844eb15b96ce393c7 |
|
25-Jan-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Bypass the cache when applying patches
Otherwise any patch that affects a register which is writable may trash
cached values.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| d9db762708e27c2892db9d8a54e735a8e506e16e |
|
25-Jan-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Skip patch application when the cache is not dirty on sync
On the basis that if we don't actually need to resync the cache then the
patches are probably also already applied.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 7e53b195e412a813e915843adc7e4d91868e8e94 |
|
25-Jan-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Unexport regcache_write() and regcache_read()
They have no current users which is fortunate as they don't take the lock
and therefore aren't safe to use externally. We'll need to add new
operations if direct cache access is needed.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 22f0d90a34827812413bb3fbeda6a2a79bb58423 |
|
21-Jan-2012 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Support register patch sets
Device manufacturers frequently provide register sequences, usually not
fully documented, to be run at startup in order to provide better defaults
for devices (for example, improving performance in the light of silicon
evaluation). Support such updates by allowing drivers to register update
sets with the core. These updates will be written to the device immediately
and will also be rewritten when the cache is synced.
The assumption is that the reason for resyncing the cache will always be
that the device has been powered off. If this turns out to not be the case
then a separate operation can be provided.
Currently the implementation only allows a single set of updates to be
specified for a device, this could be extended in future.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 94f9ec936513b9743996cf89d2f9c8e3110cf0f4 |
|
16-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Move initialization of regcache related fields to regcache_init
Move the initialization regcache related fields of the regmap struct to
regcache_init. This allows us to keep regmap and regcache code better
separated.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| bc7ee55633867909bb05e71f957a4d3c1aa1b488 |
|
30-Nov-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Add trace event for successful cache reads
Currently we only trace physical reads, there's no instrumentation if
the read is satisfied from cache.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 4c691664583ef6a91f9ed0e08a75fbd30a5ffd5c |
|
18-Nov-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Remove indexed cache type
There should be no situation where it offers any advantage over rbtree
and there are no current users so remove the code for simplicity.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| b44d48c1ccf70273a91b7d3a920b0b54c3cb314f |
|
16-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Drop check whether a register is readable in regcache_read
One of the reasons for using a cache is to have a software shadow of a register
which is writable but not readable. This allows us to do a read-modify-write
operation on such a register.
Currently regcache checks whether a register is readable when performing a
cached read and returns an error if it is not. Drop this check, since it will
prevent us from using the cache for registers where read-back is not possible.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 064d4db11e23949c40b8a2f2f6be11c131b53932 |
|
16-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Properly round cache_word_size
regcache currently only properly works with val bit sizes of 8 or 16, since
it will, when calculating the cache word size, round down. This causes the
cache storage to be too small to hold the full register value. Fix this by
rounding up instead.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 720e4616e8fd85284ef1addd8b8d93d8415e8dbc |
|
16-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Make reg_config reg_defaults const
The reg_defaults field usually points to a static per driver array, which should
not be modified. Make requirement this explicit by making reg_defaults const.
To allow this the regcache_init code needs some minor changes. Previoulsy the
reg_config was not available in regcache_init and regmap->reg_defaults was used
to pass the default register set to regcache_init. Now that the reg_config is
available we can work on it directly.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| e5e3b8abeda1cf45f5a079458dbc267952694c7a |
|
16-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Move initialization of regcache related fields to regcache_init
Move the initialization regcache related fields of the regmap struct to
regcache_init. This allows us to keep regmap and regcache code better
separated.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| bd061c78cabc28bb64ed79f784d24918b6bdb791 |
|
14-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Fix memory leak in regcache_init error path
Make sure all allocated memory gets freed again in case initializing the cache
failed.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 021cd616decb4e8a4b31f1f8c466a847e8c04e67 |
|
14-Nov-2011 |
Lars-Peter Clausen <lars@metafoo.de> |
regmap: Fix memory leak in regcache_hw_init error path
Make sure reg_defaults_raw gets freed in case of an error.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 8ae0d7e8a918e9603748abe9b31984fc5d96abb3 |
|
26-Oct-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Track if the register cache is dirty and suppress unneeded syncs
Allow drivers to optimise out the register cache sync if they didn't need
to do one. If the hardware is desynced from the register cache (by power
loss for example) then the driver should call regcache_mark_dirty() to
let the core know about this.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 1b6bc32f0a7380102499deb6aa99a59e789efb33 |
|
27-May-2011 |
Paul Gortmaker <paul.gortmaker@windriver.com> |
drivers/base: Add export.h for EXPORT_SYMBOL/THIS_MODULE as required.
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 <sfr@canb.auug.org.au> ]
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
|
| 8528bdd450d34687b380c0f87992d105bdf54ca3 |
|
09-Oct-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Allow caches for devices with no defaults
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 <broonie@opensource.wolfsonmicro.com>
Acked-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
|
| 6e6ace00a045251bd172b9b9c2379857bbff3dc7 |
|
09-Oct-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Return a sensible error code if we fail to read the cache
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 <broonie@opensource.wolfsonmicro.com>
Acked-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
|
| f094fea68f0575286c55c06141cc89ffd0049024 |
|
04-Oct-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Use bsearch() to search the register defaults
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 <broonie@opensource.wolfsonmicro.com>
Acked-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
|
| 0eef6b0415f58ed16aff95af8c92514ce5c01258 |
|
03-Oct-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Fix doc comment
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| c08604b8ae72b4fa1843a76fc7b403ddec49f8f4 |
|
03-Oct-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Optimize the lookup path to use binary search
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 <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| ac77a765cb6e3b5aa41c186ad9f37db7fdad7dbe |
|
29-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Ensure we scream if we enable cache bypass/only at the same time
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 6eb0f5e0154facfe4f0acdb9f474cde773319efc |
|
29-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Implement regcache_cache_bypass helper function
Ensure we've got a function so users can enable/disable the
cache bypass option.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| beb1a10f219ce720c13168203bd5ebe4ce7879e0 |
|
29-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Save/restore the bypass state upon syncing
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 13753a9088af23c61e2f5c10a8f3ea136d8ebab5 |
|
29-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Lock the sync path, ensure we use the lockless _regmap_write()
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 5fcd2560767cead8f0c741340e132c5417d9f73b |
|
29-Sep-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Fix apostrophe usage
An apostrophe does not mean "look out, here comes an s!".
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 2cd148f1599a425f0f3ac6753da96a1a1aa3ce76 |
|
29-Sep-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Fix lock used for regcache_cache_only()
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 38f6916976f9e964748f097be3688e334fb60f3d |
|
28-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Grab the lock in regcache_cache_only()
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| ec8a365fe62c78a16268bd1d12dfbebc2b775991 |
|
28-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Modify map->cache_bypass directly
In preperation for the upcoming patches, modify map->cache_bypass
directly. The helper functions will grab an exclusive lock. Because
we'll have acquired the same lock we need to avoid a deadlock.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| a40c282362419b8bccb75cea081992f535841085 |
|
28-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Fix regcache_sync generic implementation
We want to use regmap_write() to actually write anything
to the HW.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 954757d767a78bc4b863fa9ea703bd7f814c8a55 |
|
27-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Implement generic syncing functionality
In the absence of a sync callback, do it manually. This of course
can't take advantange of the specific optimizations of each
cache type but it will do well enough in most cases.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 92afb286d744511f51a05f8acb6c111d05737617 |
|
19-Sep-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: Allow drivers to control cache_only flag
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| e7a6db30df42234bc0f7b9a0af402838e0f146b1 |
|
19-Sep-2011 |
Mark Brown <broonie@opensource.wolfsonmicro.com> |
regmap: A cache type of _NONE behaves like a bypassed cache
Avoid extra special casing by setting the cache_bypass flag when we're
not caching.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 593600890110c02eb471cf844649dee213870416 |
|
19-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Add the regcache_sync trace event
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 2cbbb579bcbe3e11baf1c59920dcd5a780b80447 |
|
19-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Add the LZO cache support
This patch adds support for LZO compression when storing the register
cache.
For a typical device whose register map would normally occupy 25kB or 50kB
by using the LZO compression technique, one can get down to ~5-7kB. There
might be a performance penalty associated with each individual read/write
due to decompressing/compressing the underlying cache, however that should not
be noticeable. These memory benefits depend on whether the target architecture
can get rid of the memory occupied by the original register defaults cache
which is marked as __devinitconst. Nevertheless there will be some memory
gain even if the target architecture can't get rid of the original register
map, this should be around ~30-32kB instead of 50kB.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 28644c809f44498b8cd91d00b4cdb09e63b99843 |
|
19-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Add the rbtree cache support
This patch adds support for the rbtree cache compression type.
Each rbnode manages a variable length block of registers. There can be no
two nodes with overlapping blocks. Each block has a base register and a
currently top register, all the other registers, if any, lie in between these
two and in ascending order.
The reasoning behind the construction of this rbtree is simple. In the
snd_soc_rbtree_cache_init() function, we iterate over the register defaults
provided by the regcache core. For each register value that is non-zero we
insert it in the rbtree. In order to determine in which rbnode we need
to add the register, we first look if there is another register already
added that is adjacent to the one we are about to add. If that is the case
we append it in that rbnode block, otherwise we create a new rbnode
with a single register in its block and add it to the tree.
There are various optimizations across the implementation to speed up lookups
by caching the most recently used rbnode.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Tested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 195af65ca92179ac2b524d35d732dc6fecec2744 |
|
19-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Add the indexed cache support
This is the simplest form of a cache available in regcache. Any
registers whose default value is 0 are ignored. If any of those
registers are modified in the future, they will be placed in the
cache on demand. The cache layout is essentially using the provided
register defaults by the regcache core directly and does not re-map
it to another representation.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
|
| 9fabe24e9b1af84509b842731d2beaf85e66681e |
|
19-Sep-2011 |
Dimitris Papastamos <dp@opensource.wolfsonmicro.com> |
regmap: Introduce caching support
This patch introduces caching support for regmap. The regcache API
has evolved essentially out of ASoC soc-cache so most of the actual
caching types (except LZO) have been tested in the past.
The purpose of regcache is to optimize in time and space the handling
of register caches. Time optimization is achieved by not having to go
over a slow bus like I2C to read the value of a register, instead it is
cached locally in memory and can be retrieved faster. Regarding space
optimization, some of the cache types are better at packing the caches,
for e.g. the rbtree and the LZO caches. By doing this the sacrifice in
time still wins over doing I2C transactions.
Signed-off-by: Dimitris Papastamos <dp@opensource.wolfsonmicro.com>
Tested-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
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