regmap: Add debugfs file for forcing field writes

`_regmap_update_bits()` checks if the current register value differs
from the new value, and only writes to the register if they differ. When
testin

regmap: Add debugfs file for forcing field writes

`_regmap_update_bits()` checks if the current register value differs
from the new value, and only writes to the register if they differ. When
testing hardware drivers, it might be desirable to always force a
register write, for example when writing to a `regmap_field`. This
enables and simplifies testing and verification of the hardware
interaction. For example, when using a hardware mock/simulation model,
one can then more easily verify that the driver makes the correct
expected register writes during certain events.

Add a bool variable `force_write_field` and a corresponding debugfs
entry to enable this. Since this feature could interfere with driver
operation, guard it with a macro.

Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://lore.kernel.org/r/pnd1qifa7sj.fsf@axis.com
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: Provide a ram backed regmap with raw support

Provide a simple, 16 bit only, RAM backed regmap which supports raw I/O for
use in testing.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link:

regmap: Provide a ram backed regmap with raw support

Provide a simple, 16 bit only, RAM backed regmap which supports raw I/O for
use in testing.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230610-regcache-raw-kunit-v1-1-583112cd28ac@kernel.org
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: allow upshifting register addresses before performing operations

Similar to the existing reg_downshift mechanism, that is used to
translate register addresses on busses that have a smaller a

regmap: allow upshifting register addresses before performing operations

Similar to the existing reg_downshift mechanism, that is used to
translate register addresses on busses that have a smaller address
stride, it's also possible to want to upshift register addresses.

Such a case was encountered when network PHYs and PCS that usually sit
on a MDIO bus (16-bits register with a stride of 1) are integrated
directly as memory-mapped devices. Here, the same register layout
defined in 802.3 is used, but the register now have a larger stride.

Introduce a mechanism to also allow upshifting register addresses.
Re-purpose reg_downshift into a more generic, signed reg_shift, whose
sign indicates the direction of the shift. To avoid confusion, also
introduce macros to explicitly indicate if we want to downshift or
upshift.

For bisectability, change any use of reg_downshift to use reg_shift.

Signed-off-by: Maxime Chevallier <maxime.chevallier@bootlin.com>
Tested-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20230407152604.105467-1-maxime.chevallier@bootlin.com
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: Add RAM backed register map

Add a register map that is a simple array of memory, for use in
KUnit testing of the framework. This is not exposed in regmap.h
since I can't think of a non-test

regmap: Add RAM backed register map

Add a register map that is a simple array of memory, for use in
KUnit testing of the framework. This is not exposed in regmap.h
since I can't think of a non-test use case, it is purely for use
internally. To facilitate testing we track if registers have been
read or written to.

Signed-off-by: Mark Brown <broonie@kernel.org>
Link: https://lore.kernel.org/r/20230324-regmap-kunit-v2-1-b208801dc2c8@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: Add bulk read/write callbacks into regmap_config

Currently the regmap_config structure only allows the user to implement
single element register read/write using .reg_read/.reg_write callbac

regmap: Add bulk read/write callbacks into regmap_config

Currently the regmap_config structure only allows the user to implement
single element register read/write using .reg_read/.reg_write callbacks.
The regmap_bus already implements bulk counterparts of both, and is being
misused as a workaround for the missing bulk read/write callbacks in
regmap_config by a couple of drivers. To stop this misuse, add the bulk
read/write callbacks to regmap_config and call them from the regmap core
code.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Jagan Teki <jagan@amarulasolutions.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Maxime Ripard <maxime@cerno.tech>
Cc: Robert Foss <robert.foss@linaro.org>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
To: dri-devel@lists.freedesktop.org
Link: https://lore.kernel.org/r/20220430025145.640305-1-marex@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: allow a defined reg_base to be added to every address

There's an inconsistency that arises when a register set can be accessed
internally via MMIO, or externally via SPI. The VSC7514 chip al

regmap: allow a defined reg_base to be added to every address

There's an inconsistency that arises when a register set can be accessed
internally via MMIO, or externally via SPI. The VSC7514 chip allows both
modes of operation. When internally accessed, the system utilizes __iomem,
devm_ioremap_resource, and devm_regmap_init_mmio.

For SPI it isn't possible to utilize memory-mapped IO. To properly operate,
the resource base must be added to the register before every operation.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20220313224524.399947-3-colin.foster@in-advantage.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: add configurable downshift for addresses

Add an additional reg_downshift to be applied to register addresses before
any register accesses. An example of a device that uses this is a VSC7514

regmap: add configurable downshift for addresses

Add an additional reg_downshift to be applied to register addresses before
any register accesses. An example of a device that uses this is a VSC7514
chip, which require each register address to be downshifted by two if the
access is performed over a SPI bus.

Signed-off-by: Colin Foster <colin.foster@in-advantage.com>
Link: https://lore.kernel.org/r/20220313224524.399947-2-colin.foster@in-advantage.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: teach regmap to use raw spinlocks if requested in the config

Some drivers might access regmap in a context where a raw spinlock is
held. An example is drivers/irqchip/irq-ls-extirq.c, which

regmap: teach regmap to use raw spinlocks if requested in the config

Some drivers might access regmap in a context where a raw spinlock is
held. An example is drivers/irqchip/irq-ls-extirq.c, which calls
regmap_update_bits() from struct irq_chip :: irq_set_type, which is a
method called by __irq_set_trigger() under the desc->lock raw spin lock.

Since desc->lock is a raw spin lock and the regmap internal lock for
mmio is a plain spinlock (which can become sleepable on RT), this is an
invalid locking scheme and we get a splat stating that this is a
"[ BUG: Invalid wait context ]".

It seems reasonable for regmap to have an option use a raw spinlock too,
so add that in the config such that drivers can request it.

Suggested-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20210825205041.927788-2-vladimir.oltean@nxp.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: debugfs: Fix handling of name string for debugfs init delays

In regmap_debugfs_init the initialisation of the debugfs is delayed
if the root node isn't ready yet. Most callers of regmap_debu

regmap: debugfs: Fix handling of name string for debugfs init delays

In regmap_debugfs_init the initialisation of the debugfs is delayed
if the root node isn't ready yet. Most callers of regmap_debugfs_init
pass the name from the regmap_config, which is considered temporary
ie. may be unallocated after the regmap_init call returns. This leads
to a potential use after free, where config->name has been freed by
the time it is used in regmap_debugfs_initcall.

This situation can be seen on Zynq, where the architecture init_irq
callback registers a syscon device, using a local variable for the
regmap_config. As init_irq is very early in the platform bring up the
regmap debugfs root isn't ready yet. Although this doesn't crash it
does result in the debugfs entry not having the correct name.

Regmap already sets map->name from config->name on the regmap_init
path and the fact that a separate field is used to pass the name
to regmap_debugfs_init appears to be an artifact of the debugfs
name being added before the map name. As such this patch updates
regmap_debugfs_init to use map->name, which is already duplicated from
the config avoiding the issue.

This does however leave two lose ends, both regmap_attach_dev and
regmap_reinit_cache can be called after a regmap is registered and
would have had the effect of applying a new name to the debugfs
entries. In both of these cases it was chosen to update the map
name. In the case of regmap_attach_dev there are 3 users that
currently use this function to update the name, thus doing so avoids
changes for those users and it seems reasonable that attaching
a device would want to set the name of the map. In the case of
regmap_reinit_cache the primary use-case appears to be devices that
need some register access to identify the device (for example devices
in the same family) and then update the cache to match the exact
hardware. Whilst no users do currently update the name here, given the
use-case it seemed reasonable the name might want to be updated once
the device is better identified.

Signed-off-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20200917120828.12987-1-ckeepax@opensource.cirrus.com
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Add can_sleep configuration option

Regmap can't sleep if spinlock is used for the locking protection.
This patch fixes regression caused by a previous commit that switched
regmap to use fsle

regmap: Add can_sleep configuration option

Regmap can't sleep if spinlock is used for the locking protection.
This patch fixes regression caused by a previous commit that switched
regmap to use fsleep() and this broke Amlogic S922X platform.

This patch adds new configuration option for regmap users, allowing to
specify whether regmap operations can sleep and assuming that sleep is
allowed if mutex is used for the regmap locking protection.

Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Fixes: 2b32d2f7ce0a ("regmap: Use flexible sleep")
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Tested-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20200902141843.6591-1-digetx@gmail.com
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: Add regmap_noinc_write API

The regmap API had a noinc_read function added for instances where devices
supported returning data from an internal FIFO in a single read.

This commit adds the n

regmap: Add regmap_noinc_write API

The regmap API had a noinc_read function added for instances where devices
supported returning data from an internal FIFO in a single read.

This commit adds the noinc_write variant to allow writing to a non
incrementing register, this is used in devices such as the sx1301 for
loading firmware.

Signed-off-by: Ben Whitten <ben.whitten@lairdtech.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: fix comment for regmap.use_single_write

Signed-off-by: David Frey <dpfrey@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

regmap: Add regmap_noinc_read API

The regmap API usually assumes that bulk read operations will read a
range of registers but some I2C/SPI devices have certain registers for
which a such a read oper

regmap: Add regmap_noinc_read API

The regmap API usually assumes that bulk read operations will read a
range of registers but some I2C/SPI devices have certain registers for
which a such a read operation will return data from an internal FIFO
instead. Add an explicit API to support bulk read without range semantics.

Some linux drivers use regmap_bulk_read or regmap_raw_read for such
registers, for example mpu6050 or bmi150 from IIO. This only happens to
work because when caching is disabled a single regmap read op will map
to a single bus read op (as desired). This breaks if caching is enabled and
reg+1 happens to be a cacheable register.

Without regmap support refactoring a driver to enable regmap caching
requires separate I2C and SPI paths. This is exactly what regmap is
supposed to help avoid.

Suggested-by: Jonathan Cameron <jic23@kernel.org>
Signed-off-by: Crestez Dan Leonard <leonard.crestez@intel.com>
Signed-off-by: Stefan Popa <stefan.popa@analog.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Disable debugfs when locking is disabled

The recently added support for disabling the regmap internal locking left
debugfs enabled for devices with the locking disabled. This is a problem
si

regmap: Disable debugfs when locking is disabled

The recently added support for disabling the regmap internal locking left
debugfs enabled for devices with the locking disabled. This is a problem
since debugfs allows userspace to do things like initiate reads from the
hardware which will use the scratch buffers protected by the regmap locking
so could cause data corruption.

For safety address this by just disabling debugfs for these devices. That
is overly conservative since some of the debugfs files just read internal
data structures but it's much simpler to implmement and less likely to
lead to problems with tooling that works with debugfs.

Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Add hardware spinlock support

On some platforms, when reading or writing some special registers through
regmap, we should acquire one hardware spinlock to synchronize between
the multiple su

regmap: Add hardware spinlock support

On some platforms, when reading or writing some special registers through
regmap, we should acquire one hardware spinlock to synchronize between
the multiple subsystems. Thus this patch adds the hardware spinlock
support for regmap.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Allow longer flag masks for read and write

We currently only support masking the top bit for read and write
flags. Let's make the mask unsigned long and mask the bytes based
on the configure

regmap: Allow longer flag masks for read and write

We currently only support masking the top bit for read and write
flags. Let's make the mask unsigned long and mask the bytes based
on the configured register length to make things more generic.

This allows using regmap for more exotic combinations like SPI
devices that need little endian addressing.

Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Add a function to check if a regmap register is cached

Add a function to check if a regmap register is cached. This will be used
in debugfs to dump the cached values of write only registers.

regmap: Add a function to check if a regmap register is cached

Add a function to check if a regmap register is cached. This will be used
in debugfs to dump the cached values of write only registers.

Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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regmap: Fix implicit inclusion of device.h

internal.h is using dev_name() but doesn't include device.h which
defines it. Add an explicit include to avoid build problems due to
this.

Tested-by: Ale

regmap: Fix implicit inclusion of device.h

internal.h is using dev_name() but doesn't include device.h which
defines it. Add an explicit include to avoid build problems due to
this.

Tested-by: Alexander Stein <alexander.stein@systec-electronic.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

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