In the initial case when no reg_defaults values are
provided and no register value was added to the cache
yet, the cache_present bitmap is NULL. If this function
is invoked for any register it should return false
(i.e. the register is not cached) instead of true.
Signed-off-by: NIonut Nicu <ioan.nicu.ext@nsn.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

It is common to access regmap registers at bit level, using
regmap_update_bits or regmap_read functions, however the end user has to
take care of a mask or shifting. This becomes overhead when such use
cases are high. Having a common function to do this is much convenient
and less error prone.

The idea of regmap_field is simple, regmap_field gives a logical
structure to bits of the regmap register, and the driver can use this
logical entity without the knowledge of the bit positions and masks all
over the code. This way code looks much neat and it need not handle the
masks, shifts every time it access the those entities.

With this new regmap_field_read/write apis the end user can setup a
regmap field using regmap_field_init and use the return regmap_field to
read write the register field without worrying about the masks or
shifts.

Also this apis will be useful for drivers which are based on regmaps,
like some clocks or pinctrls which can work on the regmap_fields
directly without having to worry about bit positions.
Signed-off-by: NSrinivas Kandagatla <srinivas.kandagatla@st.com>
Signed-off-by: NMark Brown <broonie@linaro.org>

regmap-mmio uses a spinlock with spin_lock() and spin_unlock() for locking.
To be able to use the regmap API from different contexts (atomic vs non-atomic),
without the risk of race conditions, we need to use spin_lock_irqsave() and
spin_lock_irqrestore() instead. A new field, the spinlock_flags field, is added
to regmap struct to store the flags between regmap_{,un}lock_spinlock(). The
spinlock_flags field itself is also protected by the spinlock.

Thanks to Stephen Warren for the suggestion of this particular solution.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Allow drivers to discard parts of the register cache, for example if part
of the hardware has been reset.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The idea of holding blocks of registers in device format is shared between
at least rbtree and lzo cache formats so split out the loop that does the
sync from the rbtree code so optimisations on it can be reused.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>

The idea of maintaining a bitmap of present registers is something that
can usefully be used by other cache types that maintain blocks of cached
registers so move the code out of the rbtree cache and into the generic
regcache code.

Refactor the interface slightly as we go to wrap the set bit and enlarge
bitmap operations (since we never do one without the other) and make it
more robust for reads of uncached registers by bounds checking before we
look at the bitmap.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>

Provide a helper to do the size based index into a block of registers and
use it when reading a value.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This allows the cache to sync values directly to the device when stored
in native format and also allows asynchronous I/O.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This file lists the register ranges in the register map.  The condition
to split the range is based on whether the block is readable or not.

Ensure that we lock the `debugfs_off_cache' list whenever we access
and modify the list.  There is a possible race otherwise between the
read() operations of the `registers' file and the `range' file.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Currently the value parsing operations both return the parsed value and
modify the passed buffer. This precludes their use in places like the cache
code so split out the in place modification into a new parse_inplace()
operation.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It's more idiomatic to pass the map structure around and this means we
can use other bits of information from the map.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

We are keeping track of the maximum register as well, this will make
things easier for us in sharing this code with the code implementing
the register ranges functionality.  It also simplifies a bit the
calculations when looking for the relevant block:offset from within
the cache.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some use cases like firmware download can transfer a lot of data in quick
succession. With high speed buses these use cases can benefit from having
multiple transfers scheduled at once since this allows the bus to minimise
the delay between transfers.

Support this by adding regmap_raw_write_async(), allowing raw transfers to
be scheduled, and regmap_async_complete() to wait for them to finish.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This commit adds provision for "no-bus" usage of the regmap API. In
this configuration user can provide API with two callbacks 'reg_read'
and 'reg_write' which are to be called when reads and writes to one of
device's registers is performed. This is useful for devices that
expose registers but whose register access sequence does not fit the 'bus'
abstraction.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This commit is a preparatory commit to provide "no-bus" configuration
option for regmap API. It adds necessary plumbing needed to have the
ability to provide user define register write function.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This commit is a preparatory commit to provide "no-bus" configuration
option for regmap API. It adds necessary plumbing needed to have the
ability to provide user define register read function.
Signed-off-by: NAndrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

While for I2C and SPI devices the overhead of using rbtree for devices with
only one block of registers is negligible the same isn't always going to
be true for MMIO devices where the I/O costs are very much lower. Cater
for these devices by adding a simple flat array type for them where the
lookups are simple array accesses, taking us right back to the original
ASoC cache implementation.

Thanks to Magnus Damm for the discussion which prompted this.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Avoid doing a linear scan of the entire register map for each read() of
the debugfs register dump by recording the offsets where valid registers
exist when we first read the registers file. This assumes the set of
valid registers never changes, if this is not the case invalidation of
the cache will be required.

This could be further improved for large blocks of contiguous registers
by calculating the register we will read from within the block - currently
we do a linear scan of the block. An rbtree may also be worthwhile.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

No point in calculating them every time.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Many of the regmap enabled drivers implementing one or more of the
readable, writeable, volatile and precious methods use the same code
pattern:

	return ((reg >= X && reg <= Y) || (reg >= W && reg <= Z) || ...)

Switch to a data driven approach, using tables to describe
readable/writeable/volatile and precious registers ranges instead.
The table based check can still be overridden by passing the usual function
pointers via struct regmap_config.
Signed-off-by: NDavide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It is sometimes convenient for a regmap user to override the standard
regmap lock/unlock functions with custom functions.
For instance this can be useful in case an already existing spinlock
or mutex has to be used for locking a set of registers instead of the
internal regmap spinlock/mutex.
Note that the fast_io field of struct regmap_bus is ignored in case
custom locking functions are used.
Signed-off-by: NDavide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If a register range is named then provide a debugfs file showing the
contents of the range separately.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

For more useful diagnostics.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Devices with register paging or indirectly accessed registers can configure
register mapping to map those on virtual address range. During access to
virtually mapped register range, indirect addressing is processed
automatically, in following steps:
  1. selector for page or indirect register is updated (when needed);
  2. register in data window is accessed.

Configuration should provide minimum and maximum register for virtual range,
details of selector field for page selection, minimum and maximum register of
data window for indirect access.

Virtual range registers are managed by cache as well as direct access
registers. In order to make indirect access more efficient, selector register
should be declared as non-volatile, if possible.

struct regmap_config is extended with the following:
struct regmap_range_cfg	*ranges;
unsigned int		n_ranges;

[Also reordered debugfs init to later on since the cleanup code was
conflicting with the new cleanup code for ranges anyway -- broonie]
Signed-off-by: NKrystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Use devres to implement dev_get_regmap(). This should mean that in almost
all cases devices wishing to take advantage of framework features based on
regmap shouldn't need to explicitly pass the regmap into the framework.
This simplifies device setup a bit.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some devices does not support bulk read and write operations, for them
we have series of single write and read operations.
Signed-off-by: NAnthony Olech <Anthony.Olech@diasemi.com>
Signed-off-by: NAshish Jangam <ashish.jangam@kpitcummins.com>
[Fixed coding style, don't check use_single_rw before assign --broonie ]
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

regmap_config.reg_stride is introduced. All extant register addresses
are a multiple of this value. Users of serial-oriented regmap busses will
typically set this to 1. Users of the MMIO regmap bus will typically set
this based on the value size of their registers, in bytes, so 4 for a
32-bit register.

Throughout the regmap code, actual register addresses are used. Wherever
the register address is used to index some array of values, the address
is divided by the stride to determine the index, or vice-versa. Error-
checking is added to all entry-points for register address data to ensure
that register addresses actually satisfy the specified stride. The MMIO
bus ensures that the specified stride is large enough for the register
size.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Commit 79c64d5 "regmap: allow regmap instances to be named" changed the
prototype of regmap_debugfs_init, but didn't update the dummy inline used
when !CONFIG_DEBUGFS. Fix this.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some devices have multiple separate register regions. Logically, one
regmap would be created per region. One issue that prevents this is that
each instance will attempt to create the same debugfs files. Avoid this
by allowing regmaps to be named, and use the name to construct the
debugfs directory name.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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>

regmap_config.reg_stride is introduced. All extant register addresses
are a multiple of this value. Users of serial-oriented regmap busses will
typically set this to 1. Users of the MMIO regmap bus will typically set
this based on the value size of their registers, in bytes, so 4 for a
32-bit register.

Throughout the regmap code, actual register addresses are used. Wherever
the register address is used to index some array of values, the address
is divided by the stride to determine the index, or vice-versa. Error-
checking is added to all entry-points for register address data to ensure
that register addresses actually satisfy the specified stride. The MMIO
bus ensures that the specified stride is large enough for the register
size.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Commit 79c64d5 "regmap: allow regmap instances to be named" changed the
prototype of regmap_debugfs_init, but didn't update the dummy inline used
when !CONFIG_DEBUGFS. Fix this.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Some devices have multiple separate register regions. Logically, one
regmap would be created per region. One issue that prevents this is that
each instance will attempt to create the same debugfs files. Avoid this
by allowing regmaps to be named, and use the name to construct the
debugfs directory name.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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>

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

This was a cut'n'paste from some older code.

Since we're about to add debugfs support don't do the obvious thing and
use bool, use u32 instead (which debugfs has been using since time
immemorial).
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>