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: Mark 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: Mark 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: Davide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: Mark 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: Davide Ciminaghi <ciminaghi@gnudd.com>
Signed-off-by: Mark 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: Mark 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: Krystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: Mark 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: Mark 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: Anthony Olech <Anthony.Olech@diasemi.com>
Signed-off-by: Ashish Jangam <ashish.jangam@kpitcummins.com>
[Fixed coding style, don't check use_single_rw before assign --broonie ]
Signed-off-by: Mark 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: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark 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: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark 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: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark 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: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark 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: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Mark 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: Marc Reilly <marc@cpdesign.com.au>
Signed-off-by: Mark 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: Mark 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: Mark 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: Mark 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: Mark Brown <broonie@opensource.wolfsonmicro.com>
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>
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>
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>
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>
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>
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>
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>
Make the debugfs stubs static inline to avoid future compilation issues due to
duplicated symbols when CONFIG_DEBUG_FS=n once internal.h is included by
multiple source files.
Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark 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: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
We're going to be using these in quite a few places so factor out the
readable/writable/volatile/precious checks.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Copy over the read parts of the ASoC debugfs implementation into regmap,
allowing users to see what the register values the device has are at
runtime. The implementation, especially the support for seeking, is
mostly due to Dimitris Papastamos' work in ASoC.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
