_regmap_raw_write() contains code to call regcache_write() to write
values to the cache. That code calls memcpy() to copy the value data to
the start of the work_buf. However, at least when _regmap_raw_write() is
called from _regmap_bus_raw_write(), the value data is in the work_buf,
and this memcpy() operation may over-write part of that value data,
depending on the value of reg_bytes + pad_bytes. At least when using
reg_bytes==1 and pad_bytes==0, corruption of the value data does occur.

To solve this, remove the memcpy() operation, and modify the subsequent
.parse_val() call to parse the original value buffer directly.

At least in the case of 8-bit register address and 16-bit values, and
writes of single registers at a time, this memcpy-then-parse combination
used to cancel each-other out; for a work-buffer containing xx 89 03,
the memcpy changed it to 89 03 03, and the parse_val changed it back to
89 89 03, thus leaving the value uncorrupted. This appears completely
accidental though. Since commit 8a819ff8 "regmap: core: Split out in
place value parsing", .parse_val only returns the parsed value, and does
not modify the buffer, and hence does not (accidentally) undo the
corruption caused by memcpy(). This caused bogus values to get written
to HW, thus preventing e.g. audio playback on systems with a WM8903
CODEC. This patch fixes that.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This reverts commit bc8ce4 (regmap: don't corrupt work buffer in
_regmap_raw_write()) since it turns out that it can cause issues when
taken in isolation from the other changes in -next that lead to its
discovery.  On the basis that nobody noticed the problems for quite some
time without that subsequent work let's drop it from v3.9.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Let's only write once...
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Mainly useful internally but exported since this is a public API that's
being checked for.
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>

Don't grind to a screaming halt, just generate a warning.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

_regmap_raw_write() contains code to call regcache_write() to write
values to the cache. That code calls memcpy() to copy the value data to
the start of the work_buf. However, at least when _regmap_raw_write() is
called from _regmap_bus_raw_write(), the value data is in the work_buf,
and this memcpy() operation may over-write part of that value data,
depending on the value of reg_bytes + pad_bytes. At least when using
reg_bytes==1 and pad_bytes==0, corruption of the value data does occur.

To solve this, remove the memcpy() operation, and modify the subsequent
.parse_val() call to parse the original value buffer directly.

At least in the case of 8-bit register address and 16-bit values, and
writes of single registers at a time, this memcpy-then-parse combination
used to cancel each-other out; for a work-buffer containing xx 89 03,
the memcpy changed it to 89 03 03, and the parse_val changed it back to
89 89 03, thus leaving the value uncorrupted. This appears completely
accidental though. Since commit 8a819ff8 "regmap: core: Split out in
place value parsing", .parse_val only returns the parsed value, and does
not modify the buffer, and hence does not (accidentally) undo the
corruption caused by memcpy(). This caused bogus values to get written
to HW, thus preventing e.g. audio playback on systems with a WM8903
CODEC. This patch fixes that.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

In the rbtree code we are exposing statistics relating to the
number of nodes/registers of the rbtree cache for each of the
devices.  Ensure that `map->debugfs' has been initialized before
we attempt to initialize the debugfs entry for the rbtree cache.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org

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>

Trace when we start and complete async writes, and when we start and
finish blocking for their completion. This is useful for performance
analysis of the resulting I/O patterns.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

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

This fixes below build error when CONFIG_REGMAP=y && CONFIG_REGMAP_SPI=m

ERROR: "regmap_async_complete_cb" [drivers/base/regmap/regmap-spi.ko] undefined!
make[1]: *** [__modpost] Error 1
make: *** [modules] Error 2
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This fixes:

drivers/base/regmap/regmap.c: In function 'regmap_async_complete_cb':
drivers/base/regmap/regmap.c:1656:3: error: 'TASK_NORMAL' undeclared (first use in this function)
drivers/base/regmap/regmap.c:1656:3: note: each undeclared identifier is reported only once for each function it appears in
drivers/base/regmap/regmap.c: In function 'regmap_async_complete':
drivers/base/regmap/regmap.c:1688:2: error: 'TASK_UNINTERRUPTIBLE' undeclared (first use in this function)
drivers/base/regmap/regmap.c:1688:2: error: implicit declaration of function 'schedule'

An alternative might be to adjust linux/wait.h to include linux/sched.h,
but since that hasn't been done before, I assume we're consciously
avoiding doing that.
Signed-off-by: NStephen Warren <swarren@nvidia.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>

Signed-off-by: NNestor Ovroy <novroy@riseup.net>
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>

Since regmap already has support for formatting 24 bit wide values, so adding
support for 24 bit wide registers is pretty much straight forward.
Signed-off-by: NLars-Peter Clausen <lars@metafoo.de>
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>

This seems to be the most common way of reporting register numbers, it's
certainly what we do for trace.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

val_bytes is of 'size_t', so it should be printed as '%zu'.

Fixes the following build warning on x86:

drivers/base/regmap/regmap.c:872:4: warning: format '%d' expects argument of type 'int', but argument 5 has type 'size_t' [-Wformat]
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.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>

Building regmap.o triggers this GCC warning:
    drivers/base/regmap/regmap.c: In function ‘regmap_raw_read’:
    drivers/base/regmap/regmap.c:1172:6: warning: ‘ret’ may be used uninitialized in this function [-Wmaybe-uninitialized]

Long story short: Jakub Jelinek pointed out that there is a type
mismatch between 'num' in regmap_volatile_range() and 'val_count' in
regmap_raw_read(). And indeed, converting 'num' to the type of
'val_count' (ie, size_t) makes this warning go away.
Signed-off-by: NPaul Bolle <pebolle@tiscali.nl>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If a block write covers a paged memory region and crosses a window
boundary then rather than failing the write split the transfer up
into multiple writes, making the whole process more transparent for
drivers.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The range code was written to check for return codes less than zero as
errors but throughout the rest of the API return codes not equal to zero
are errors. Change all these checks to match the house style.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This will support a subsequent update to allow bulk writes to cross window
boundaries.
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>

Rather than just returning a single error code for every possible thing we
can notice print an error message saying what the problem was. This makes
it very much easier to figure out what's wrong and fix it.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This makes things consistent with the rest of the API and is actually what
the documentation says. We don't currently have any in tree users so low
cost.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

When bus->fast_io is set, the locking here is done with spinlocks.
This is currently true for the regmap-mmio bus implementation.

While holding a spinlock we can't go to sleep, various operations
like removing the debugfs entries or re-initializing the cache will
sleep, therefore, shift the locking up to the user.
Signed-off-by: NDimitris Papastamos <dp@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Sometimes for failures during very early init the trace infrastructure
isn't available early enough to be used.  For this sort of problem
defining LOG_DEVICE will add printks for basic register I/O on a specific
device, allowing trace to be extracted when the trace system doesn't come
up early enough to work with.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

After page update, orginal work_buf has to be restored regardless of
the result.
Signed-off-by: NKrystian Garbaciak <krystian.garbaciak@diasemi.com>
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>

Locks are moved to regmap_update_bits(), which allows to reenter internal
function _regmap_update_bits() from inside of regmap read/write routines.
Signed-off-by: NKrystian Garbaciak <krystian.garbaciak@diasemi.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

It's supposed to be there for drivers.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The word to be transmitted/received via regmap is composed by the following
parts:

config->reg_bits
config->val_bits
config->pad_bits

,so the total size should be calculated by summing up the number of bits of
each element and using a DIV_ROUND_UP to return the number of bytes.
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

If debugfs isn't cleaned up, stale files will be left in the filesystem
which will cause an OOPS when accessed the first time, and hang the
accessing application when accessed again, presumably due to some lock
being left held.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Add a field to struct regmap_bus that allows bus drivers to request that
register addresses and values be formatted with a specific endianness.

The default endianness is unchanged from current operation: Big.

Implement native endian formatting/parsing for 16- and 32-bit values.
This will be enough to support regmap-mmio.c.
Signed-off-by: NStephen Warren <swarren@nvidia.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>