Some bus types have very fast IO. For these, acquiring a mutex for every
IO operation is a significant overhead. Allow busses to indicate their IO
is fast, and enhance regmap to use a spinlock for those busses.

[Currently limited to native endian registers -- broonie]
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The only context needed by I2C and SPI bus definitions is the device
itself; this can be converted to an i2c_client or spi_device in order
to perform IO on the device. However, other bus types may need more
context in order to perform IO. Enable this by having regmap_init accept
a bus_context parameter, and pass this to all bus callbacks. The
existing callbacks simply pass the struct device here. Future bus types
may pass something else.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This change combines any padding bits into the register address bits when
determining register format handlers to use the next byte-divisible
register size.
A reg_shift member is introduced to the regmap struct to enable fixup
of the reg format.
Format handlers now take an extra parameter specifying the number of
bits to shift the value by.
Signed-off-by: NMarc Reilly <marc@cpdesign.com.au>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Add support for devices with 24 data bits.
Signed-off-by: NMarc Reilly <marc@cpdesign.com.au>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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: NPaul Gortmaker <paul.gortmaker@windriver.com>

[Fix for breakage which will be introduced during the merge window via
header reworks in another tree, the regmap tree does include device.h
but Paul's tree breaks that.  Reworded subject to reflect -- broonie]

regmap.s uses devres_alloc() and others that are prototyped in device.h.
Include that to solve the following:

drivers/base/regmap/regmap.c: In function 'devm_regmap_init':
drivers/base/regmap/regmap.c:331:2: error: implicit declaration of function 'devres_alloc' [-Werror=implicit-function-declaration]
drivers/base/regmap/regmap.c:338:3: error: implicit declaration of function 'devres_add' [-Werror=implicit-function-declaration]
drivers/base/regmap/regmap.c:340:3: error: implicit declaration of function 'devres_free' [-Werror=implicit-function-declaration]
drivers/base/regmap/regmap.c: In function '_regmap_raw_write':
drivers/base/regmap/regmap.c:421:5: error: implicit declaration of function 'dev_err' [-Werror=implicit-function-declaration]
Signed-off-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Remove unused module.h and/or replace with export.h
as required.
Signed-off-by: NPaul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Fall back to a register by register read to do so; most likely we'll be
cache only so the overhead will be low.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Generic infrastructure based on top of regmap may want to operate on
blocks of data and therefore find it useful to find the size of the
register values. Provide an accessor operation for this.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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

The bulk_write() supports the data transfer to multi
register which takes the data into cpu_endianness format
and does formatting of data to device format before
sending to device.
The transfer can be completed in single transfer or multiple
transfer based on data formatting.
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Adding support for caching of data into the
non-volatile register from the call of reg_raw_write().

This will allow the larger block of data write into multiple
register without worrying whether register is cached or not
through reg_raw_write().
Signed-off-by: NLaxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The first parameter should be "number of elements" and the second parameter
should be "element size".
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Save error handling and unwinding code in drivers by providing managed
versions of the regmap init functions, simplifying usage.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Using .format_write means, we have a custom function to write to the
chip, but not to read back. Also, mark registers as "not precious" and
"not volatile" which is implicit because we cannot read them. Make those
functions use 'regmap_readable' to reuse the checks done there.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

For the upcoming 2/6-format, we don't see debugfs output otherwise,
since the current division results in 0. I'd think 10/14 is broken
currently, too.
Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Signed-off-by: NWolfram Sang <w.sang@pengutronix.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Most of the data exposed via debugfs is for or from the cache so reset
all the debugfs configuration to make sure everything is up to date with
the latest configuration, especially if we're changing cache type.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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: NMark Brown <broonie@opensource.wolfsonmicro.com>

When we reinitialise the cache make sure that we reset the cache access
flags, ensuring that the reinitialised cache is in the default state
which is what callers would and do expect given the function name.

This is particularly likely to cause issues in systems where there was no
cache previously as those systems have cache bypass enabled, as for the
wm8994 driver where this was noticed.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some devices, especially those with high speed control interfaces, require
padding between the register and the data. Support this in the regmap API
by providing a pad_bits configuration parameter.

Only devices with integer byte counts are supported.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Sometimes the register map information may change in ways that drivers can
discover at runtime. For example, new revisions of a device may add new
registers. Support runtime discovery by drivers by allowing the register
cache to be reinitialised with a new function regmap_reinit_cache() which
discards the existing cache and creates a new one.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some users of regmap_update_bits() would like to be able to tell their
users if they actually did an update so provide a variant which also
returns a flag indicating if an update took place. We could return a
tristate in the return value of regmap_update_bits() but this makes the
API more cumbersome to use and doesn't fit with the general zero for
success idiom we have.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This allows caches to add custom debugfs files.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If the new register value is identical to the original one then suppress
the write to the hardware in regmap_update_bits(), saving some I/O cost.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This patch adds support for 10 bits register, 14 bits value type register
formating. This is for example used by the Analog Devices AD5380.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

For some register format types we do not provide a parse_val so we can not do a
hardware read. But a cached read is still possible, so try to read from the
cache first, before checking whether a hardware read is possible. Otherwise the
cache becomes pretty useless for these register types.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The regmap_init documentation states that it will either return a pointer to a
valid regmap structure or a ERR_PTR in case of an error. Currently it returns a
NULL pointer in case no bus or no config was given. Since NULL is not a
ERR_PTR a caller might assume that it is a pointer to a valid regmap structure,
so return a ERR_PTR(-EINVAL) instead.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If regcache initialization fails regmap_init will currently exit without
freeing work_buf.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Commit 10a08d9f ("regmap: Support some block operations on cached devices")
allowed raw read operations without throwing a warning when using caches if
all registers are volatile. This patch does the same for raw write operations.

This is for example useful when loading a firmware in a predefined volatile
region on a chip where we otherwise want registers to be cached.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We already have the same code for checking whether a register range is volatile
in two different places. Instead of duplicating it once more  add a small helper
function for checking whether a register range is voltaile.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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: NMark Brown <broonie@opensource.wolfsonmicro.com>

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

Support raw reads if all the registers being read are volatile, the cache
will have no impact for tem.

Support bulk reads either directly (if all the registers are volatile) or
by falling back to iterating over single register reads otherwise.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

As with the bulk reads we really should be able to make these play
nicely with the cache but warn for now.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>

Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This patch incorporates the regcache core code into regmap.  All previous
patches have been no-ops essentially up to this point.

The bulk read operation is not supported by regcache at the moment.  This
will be implemented incrementally.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Tested-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some buses like SPI have no standard notation of read or write operations.
The general scheme here is to set or clear specific bits in the register
address to indicate whether the operation is a read or write. We already
support having a read flag mask per bus, but as there is no standard
the bits which need to be set or cleared differ between devices and vendors,
thus we need a mechanism to specify them per device.

This patch adds two new entries to the regmap_config struct, read_flag_mask and
write_flag_mask. These will be or'ed onto the top byte when doing a read or
write operation. If both masks are empty the device will fallback to the
regmap_bus masks.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>