regmap: fix bogus error on regcache_sync success

commit fea88064445a59584460f7f67d102b6e5fc1ca1d upstream.

Since commit 0ec7731655de ("regmap: Ensure range selector registers
are updated after cach

regmap: fix bogus error on regcache_sync success

commit fea88064445a59584460f7f67d102b6e5fc1ca1d upstream.

Since commit 0ec7731655de ("regmap: Ensure range selector registers
are updated after cache sync") opening pcm512x based soundcards fail
with EINVAL and dmesg shows sync cache and pm_runtime_get errors:

[ 228.794676] pcm512x 1-004c: Failed to sync cache: -22
[ 228.794740] pcm512x 1-004c: ASoC: error at snd_soc_pcm_component_pm_runtime_get on pcm512x.1-004c: -22

This is caused by the cache check result leaking out into the
regcache_sync return value.

Fix this by making the check local-only, as the comment above the
regcache_read call states a non-zero return value means there's
nothing to do so the return value should not be altered.

Fixes: 0ec7731655de ("regmap: Ensure range selector registers are updated after cache sync")
Cc: stable@vger.kernel.org
Signed-off-by: Matthias Reichl <hias@horus.com>
Link: https://lore.kernel.org/r/20231203222216.96547-1-hias@horus.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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regmap: Ensure range selector registers are updated after cache sync

commit 0ec7731655de196bc1e4af99e495b38778109d22 upstream.

When we sync the register cache we do so with the cache bypassed in or

regmap: Ensure range selector registers are updated after cache sync

commit 0ec7731655de196bc1e4af99e495b38778109d22 upstream.

When we sync the register cache we do so with the cache bypassed in order
to avoid overhead from writing the synced values back into the cache. If
the regmap has ranges and the selector register for those ranges is in a
register which is cached this has the unfortunate side effect of meaning
that the physical and cached copies of the selector register can be out of
sync after a cache sync. The cache will have whatever the selector was when
the sync started and the hardware will have the selector for the register
that was synced last.

Fix this by rewriting all cached selector registers after every sync,
ensuring that the hardware and cache have the same content. This will
result in extra writes that wouldn't otherwise be needed but is simple
so hopefully robust. We don't read from the hardware since not all
devices have physical read support.

Given that nobody noticed this until now it is likely that we are rarely if
ever hitting this case.

Reported-by: Hector Martin <marcan@marcan.st>
Cc: stable@vger.kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20231026-regmap-fix-selector-sync-v1-1-633ded82770d@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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regcache: Push async I/O request down into the rbtree cache

Currently the regcache core unconditionally enables async I/O for all cache
types, causing problems for the maple tree cache which dynamic

regcache: Push async I/O request down into the rbtree cache

Currently the regcache core unconditionally enables async I/O for all cache
types, causing problems for the maple tree cache which dynamically allocates
the buffers used to write registers to the device since async requires the
buffers to be kept around until the I/O has been completed.

This use of async I/O is mainly for the rbtree cache which stores data in
a format directly usable for regmap_raw_write(), though there is a special
case for single register writes which would also have allowed it to be used
with the flat cache. It is a bit of a landmine for other caches since it
implicitly converts sync operations to async, and with modern hardware it
is not clear that async I/O is actually a performance win as shown by the
performance work David Jander did with SPI. In multi core systems the cost
of managing concurrency ends up swamping the performance benefit and almost
all modern systems are multi core.

Address this by pushing the enablement of async I/O down into the rbtree
cache where it is actively used, avoiding surprises for other cache
implementations.

Reported-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Fixes: bfa0b38c1483 ("regmap: maple: Implement block sync for the maple tree cache")
Reviewed-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Tested-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230719-regcache-async-rbtree-v1-1-b03d30cf1daf@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Let users check if a register is cached

The HDA driver has a use case for checking if a register is cached which
it bodges in awkwardly and unclearly. Provide an API which allows it to
direc

regmap: Let users check if a register is cached

The HDA driver has a use case for checking if a register is cached which
it bodges in awkwardly and unclearly. Provide an API which allows it to
directly do what it's trying to do.

Reviewed-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230717-regmap-cache-check-v1-1-73ef688afae3@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: cache: Revert "Add 64-bit mode support"

There is no support for 64-bit data size in regmap, so
there is no point to have it in regmap cache.

This reverts commit 8b7663de6e2bfe3c40e1846e1c46

regmap: cache: Revert "Add 64-bit mode support"

There is no support for 64-bit data size in regmap, so
there is no point to have it in regmap cache.

This reverts commit 8b7663de6e2bfe3c40e1846e1c4625f33d138757.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230622183613.58762-3-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: regcache: Don't sync read-only registers

regcache_maple_sync() tries to sync all cached values no matter
whether it's writable or not. OTOH, regache_sync_val() does care the
wrtability and

regmap: regcache: Don't sync read-only registers

regcache_maple_sync() tries to sync all cached values no matter
whether it's writable or not. OTOH, regache_sync_val() does care the
wrtability and returns -EIO for a read-only register. This results in
an error message like:
snd_hda_codec_realtek hdaudioC0D0: Unable to sync register 0x2f0009. -5
and the sync loop is aborted incompletely.

This patch adds the writable register check to regcache_sync_val() for
addressing the bug above.

Note that, although we may add the check in the caller side
(regcache_maple_sync()), here we put in regcache_sync_val(), so that a
similar case like this can be avoided in future.

Fixes: f033c26de5a5 ("regmap: Add maple tree based register cache")
Link: https://lore.kernel.org/r/877cs7g6f1.wl-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Link: https://lore.kernel.org/r/20230613112240.3361-1-tiwai@suse.de
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Don't check for changes in regcache_set_val()

The only user of regcache_set_val() ignores the return value so we may as
well not bother checking if the value we are trying to set is the same

regmap: Don't check for changes in regcache_set_val()

The only user of regcache_set_val() ignores the return value so we may as
well not bother checking if the value we are trying to set is the same as
the value already stored.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230609-regcache-set-val-no-ret-v1-1-9a6932760cf8@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: maple: Implement block sync for the maple tree cache

For register maps where we can write multiple values in a single bus
operation it is generally much faster to do so. Improve the performa

regmap: maple: Implement block sync for the maple tree cache

For register maps where we can write multiple values in a single bus
operation it is generally much faster to do so. Improve the performance of
maple tree cache syncs on such devices by identifying blocks of adjacent
registers that need to be written out and combining them into a single
operation.

Combining writes does mean that we need to allocate a scratch buffer and
format the data into it but it is expected that for most cases where caches
are in use the cost of I/O will be much greater than the cost of doing the
allocation and format.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230609-regcache-maple-sync-raw-v1-1-8ddeb4e2b9ab@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Add maple tree based register cache

The current state of the art for sparse register maps is the
rbtree cache. This works well for most applications but isn't
always ideal for sparser regis

regmap: Add maple tree based register cache

The current state of the art for sparse register maps is the
rbtree cache. This works well for most applications but isn't
always ideal for sparser register maps since the rbtree can get
deep, requiring a lot of walking. Fortunately the kernel has a
data structure intended to address this very problem, the maple
tree. Provide an initial implementation of a register cache
based on the maple tree to start taking advantage of it.

The entries stored in the maple tree are arrays of register
values, with the maple tree keys holding the register addresses.
We store data in host native format rather than device native
format as we do for rbtree, this will be a benefit for devices
where we don't marshal data within regmap and simplifies the code
but will result in additional CPU overhead when syncing the cache
on devices where we do marshal data in regmap.

This should work well for a lot of devices, though there's some
additional areas that could be looked at such as caching the
last accessed entry like we do for rbtree and trying to minimise
the maple tree level locking. We should also use bulk writes
rather than single register writes when resyncing the cache where
possible, even if we don't store in device native format.

Very small register maps may continue to to better with rbtree
longer term.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230325-regcache-maple-v3-2-23e271f93dc7@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Factor out single value register syncing

In order to support sparse caches that don't store data in raw format
factor out the parts of the raw block sync implementation that deal with
writin

regmap: Factor out single value register syncing

In order to support sparse caches that don't store data in raw format
factor out the parts of the raw block sync implementation that deal with
writing a single register via _regmap_write().

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230325-regcache-maple-v3-1-23e271f93dc7@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Removed compressed cache support

The compressed register cache support has assumptions that make it hard to
cover in testing, mainly that it requires raw registers defaults be
provided. Rath

regmap: Removed compressed cache support

The compressed register cache support has assumptions that make it hard to
cover in testing, mainly that it requires raw registers defaults be
provided. Rather than either address these assumptions or leave it untested
by the forthcoming KUnit tests let's remove it, the use case is quite thin
and there are no current users.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regcache-lzo-v1-1-08c5d63e2a5e@kernel.org

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regmap: Clarify error for unknown cache types

The error message printed when we fail to locate the cache type the map
requested says it can't find a compress type rather than a cache type,
fix that.

regmap: Clarify error for unknown cache types

The error message printed when we fail to locate the cache type the map
requested says it can't find a compress type rather than a cache type,
fix that. Since the compressed type is the only one currently compiled
conditionally it's likely to be the missing type but that might not always
be true and is still unclear.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regcache-unknown-v1-1-80deecbf196b@kernel.org

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regmap: Handle sparse caches in the default sync

If there is no cache entry available we will get -ENOENT from the cache
implementation, handle this gracefully and skip rather than treating it as
an

regmap: Handle sparse caches in the default sync

If there is no cache entry available we will get -ENOENT from the cache
implementation, handle this gracefully and skip rather than treating it as
an error.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230325-regcache-sparse-sync-v1-1-2a890239d061@kernel.org

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regmap: cache: Silence checkpatch warning

checkpatch.pl warned:
WARNING: ENOSYS means 'invalid syscall nr' and nothing else
Align the return value to regcache_drop_region().

Signed-off-by: Alexande

regmap: cache: Silence checkpatch warning

checkpatch.pl warned:
WARNING: ENOSYS means 'invalid syscall nr' and nothing else
Align the return value to regcache_drop_region().

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230313071812.13577-2-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: cache: Return error in cache sync operations for REGCACHE_NONE

There is no sense in doing a cache sync on REGCACHE_NONE regmaps.
Instead of panicking the kernel due to missing cache_ops, ret

regmap: cache: Return error in cache sync operations for REGCACHE_NONE

There is no sense in doing a cache sync on REGCACHE_NONE regmaps.
Instead of panicking the kernel due to missing cache_ops, return an error
to client driver.

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Link: https://lore.kernel.org/r/20230313071812.13577-1-alexander.stein@ew.tq-group.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: cache: Add extra parameter check in regcache_init

When num_reg_defaults > 0 but reg_defaults is NULL, there will be a
NULL pointer exception.

Current code has no such usage, but as addition

regmap: cache: Add extra parameter check in regcache_init

When num_reg_defaults > 0 but reg_defaults is NULL, there will be a
NULL pointer exception.

Current code has no such usage, but as additional hardening, also
check this to prevent any chance of crashing.

Signed-off-by: Schspa Shi <schspa@gmail.com>
Link: https://lore.kernel.org/r/20220629130951.63040-1-schspa@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Don't warn about cache only mode for devices with no cache

For devices with no cache it can make sense to use cache only mode as a
mechanism for trapping writes to hardware which is inaccess

regmap: Don't warn about cache only mode for devices with no cache

For devices with no cache it can make sense to use cache only mode as a
mechanism for trapping writes to hardware which is inaccessible but since
no cache is equivalent to cache bypass we force such devices into bypass
mode. This means that our check that bypass and cache only mode aren't both
enabled simultanously is less sensible for devices without a cache so relax
it.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20220622171723.1235749-1-broonie@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: cache: Fix syntax errors in comments

Delete the redundant word 'the'.

Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com>
Link: https://lore.kernel.org/r/20220604041603.9697-1-wangxiang@cdjrl

regmap: cache: Fix syntax errors in comments

Delete the redundant word 'the'.

Signed-off-by: Xiang wangx <wangxiang@cdjrlc.com>
Link: https://lore.kernel.org/r/20220604041603.9697-1-wangxiang@cdjrlc.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: cache: set max_register with reg_stride

Current logic does not consider multi-stride cases,
the max_register have to calculate with reg_stride
because it is a kind of address range.

Signed-

regmap: cache: set max_register with reg_stride

Current logic does not consider multi-stride cases,
the max_register have to calculate with reg_stride
because it is a kind of address range.

Signed-off-by: Jeongtae Park <jtp.park@samsung.com>
Link: https://lore.kernel.org/r/20220425114613.15934-1-jtp.park@samsung.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Assign boolean values to a bool variable

Fix the following coccicheck warnings:

./drivers/base/regmap/regcache.c:71:3-18: WARNING: Assignment of
0/1 to bool variable.

Reported-by: Abaci Ro

regmap: Assign boolean values to a bool variable

Fix the following coccicheck warnings:

./drivers/base/regmap/regcache.c:71:3-18: WARNING: Assignment of
0/1 to bool variable.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Zhong <abaci-bugfix@linux.alibaba.com>
Link: https://lore.kernel.org/r/1611215961-33725-1-git-send-email-abaci-bugfix@linux.alibaba.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: fix page selection for noinc writes

Non-incrementing writes can fail if register + length crosses page
border. However for non-incrementing writes we should not check for page
border crossin

regmap: fix page selection for noinc writes

Non-incrementing writes can fail if register + length crosses page
border. However for non-incrementing writes we should not check for page
border crossing. Fix this by passing additional flag to _regmap_raw_write
and passing length to _regmap_select_page basing on the flag.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Fixes: cdf6b11daa77 ("regmap: Add regmap_noinc_write API")
Link: https://lore.kernel.org/r/20200917153405.3139200-2-dmitry.baryshkov@linaro.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: add proper SPDX identifiers on files that did not have them.

There were a few files in the regmap code that did not have SPDX
identifiers on them, so fix that up. At the same time, remove t

regmap: add proper SPDX identifiers on files that did not have them.

There were a few files in the regmap code that did not have SPDX
identifiers on them, so fix that up. At the same time, remove the "free
form" text that specified the license of the file, as that is impossible
for any tool to properly parse.

Also, as Mark loves // comment markers, convert all of the headers to be
the same to make things look consistent :)

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Fix typo in IS_ENABLED() check

Reported-by: Andreas Ziegler <andreas.ziegler@fau.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: make LZO cache optional

Commit 2cbbb579bcbe3 ("regmap: Add the LZO cache support") added support
for LZO compression in regcache, but there were never any users added
afterwards. Since LZO s

regmap: make LZO cache optional

Commit 2cbbb579bcbe3 ("regmap: Add the LZO cache support") added support
for LZO compression in regcache, but there were never any users added
afterwards. Since LZO support itself has its own size, it currently is
rather a deoptimization.

So make it optional by introducing a symbol that can be selected by
drivers wanting to make use of it.

Saves e.g. ~46 kB on MIPS (size of LZO support + regcache LZO code).

Signed-off-by: Jonas Gorski <jonas.gorski@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Fixup the kernel-doc comments on functions/structures

Most of the kernel-doc comments in regmap don't actually generate
correctly. This patch fixes up a few common issues, corrects some typo

regmap: Fixup the kernel-doc comments on functions/structures

Most of the kernel-doc comments in regmap don't actually generate
correctly. This patch fixes up a few common issues, corrects some typos
and adds some missing argument descriptions.

The most common issues being using a : after the function name which
causes the short description to not render correctly and not separating
the long and short descriptions of the function. There are quite a few
instances of arguments not being described or given the wrong name as
well.

This patch doesn't fixup functions/structures that are currently missing
descriptions.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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