Bulk reads may potentially read a lot of registers and regmap_read will
take and release the regmap lock for each register. Avoid bouncing
the lock so frequently by holding the lock locally and calling
_regmap_read instead. This also has the nice side-effect that all the
reads will be done atomically so no other threads can sneak a write in
during the regmap_bulk_read.
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Raw reads may need to be split into small chunks if max_raw_read is
set.  Tidy up the code implementing this, the new code is slightly
clearer, slightly shorter and slightly more efficient.
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Currently regmap_bulk_read will split a read into chunks before
calling regmap_raw_read if max_raw_read is set. It is more logical for
this handling to be inside regmap_raw_read itself, as this removes the
need to keep re-implementing the chunking code, which would be the
same for all users of regmap_raw_read.
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

As a helper function exists for calculating register offsets lets use
that rather than open coding with the reg_stride.
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

A bulk read can be implemented either through regmap_raw_read, or
by reading each register individually using regmap_read.  Both
regmap_read and regmap_bulk_read should return values in native
endian. In the individual case the current implementation calls
format_val to put the data into the output array, which can cause
endian issues. The regmap_read will have already converted the data
into native endian, if the hosts endian differs from the device then
format_val will switch the endian back again.

Rather than using format_val simply use the code that is called if
there is no format_val function. This code supports all cases except
24-bit but there don't appear to be any users of regmap_bulk_read for
24-bit. Additionally, it would have to be a big endian host for the
old code to actually function correctly anyway.

Fixes: 15b8d2c4 ("regmap: Fix regmap_bulk_read in BE mode")
Reported-by: NDavid Rhodes <david.rhodes@cirrus.com>
Signed-off-by: NCharles Keepax <ckeepax@opensource.cirrus.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

We're supposed to be checking that "val_len" is not too large but
instead we check if it is smaller than the max.

The only function affected would be regmap_i2c_smbus_i2c_write() in
drivers/base/regmap/regmap-i2c.c.  Strangely that function has its own
limit check which returns an error if (count >= I2C_SMBUS_BLOCK_MAX) so
it doesn't look like it has ever been able to do anything except return
an error.

Fixes: c335931e ("regmap: Add raw_write/read checks for max_raw_write/read sizes")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NMark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

All zero read and write masks in the regmap config are used to signal no
special mask is needed and the bus defaults are used. In some devices
all zero read/write masks are the special mask and bus defaults should
not be used. To signal this a new variable is added.

For example SPI often sets bit 7 in address to signal to the device a
read is requested. On TI AFE44xx parts with SPI interfaces no bit
needs to be set as registers are either read or write only and the
operation can be determined from the address only. For this case both
masks must be zero to not effect the address.
Signed-off-by: NAndrew F. Davis <afd@ti.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Since the hwlock id 0 is valid for hardware spinlock core, but now id 0
is treated as one invalid value for regmap. Thus we should add one extra
flag for regmap config to indicate if a hardware spinlock should be used,
then id 0 can be valid for regmap to request.
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

The map->work_buf is a buffer preallocated in __regmap_init() with size
allowing it to store all 3 parts of a buffer - reg, pad and val. While
reg and val parts are always properly setup before each transaction, the
pad part is left at its default value (zeros). Until it is overwritten,
that is.

_regmap_bus_read(), when calling _regmap_raw_read() uses beginning of
work_buf as a place to store data read. Usually that is fine but if
val_bits > reg_bits && pad_bits > 0, padding area of work_buf() may get
overwritten. Since padding is not zeroed before each transaction,
garbage will be used on next calls.

This patch moves the val pointer used for _regmap_raw_read() to point
to a part of work_buf intended for storing value read.
Signed-off-by: NKrzysztof Adamski <krzysztof.adamski@nokia.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Currently we just copy over the pointer passed to regmap_init() in
the regmap config struct. To be on the safe side: duplicate the string
with kstrdup_const() so that if an unaware user passes an address to
a stack-allocated buffer, we won't crash.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NMark Brown <broonie@kernel.org>

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: NLars-Peter Clausen <lars@metafoo.de>
Signed-off-by: NMark Brown <broonie@kernel.org>

Minor naming convention tweak.
Suggested-by: NAndy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NMark Brown <broonie@kernel.org>

We have a use case in the at24 EEPROM driver (recently converted to
using regmap instead of raw i2c/smbus calls) where we read from/write
to the regmap in a loop, while protecting the entire loop with
a mutex.

Currently this implicitly makes us use two mutexes - one in the driver
and one in regmap. While browsing the code for similar use cases I
noticed a significant number of places where locking *seems* redundant.

Allow users to completely disable any locking mechanisms in regmap
config.
Signed-off-by: NBartosz Golaszewski <brgl@bgdev.pl>
Signed-off-by: NMark Brown <broonie@kernel.org>

The hwspinlock was changed to a bool by commit d048236d
("hwspinlock: Change hwspinlock to a bool"), so we do not need
the REGMAP_HWSPINLOCK config to select hwspinlock or not.
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch fixes the warning of label 'err_map' defined but not used.
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

We should free any hwspinlocks when we destroy the regmap, do so.
Signed-off-by: NMark Brown <broonie@kernel.org>

The previous patch to allow the hwspinlock code to be disabled missed
handling the free in the error path, do so using the better IS_ENABLED()
pattern as suggested by Baolin. While we're at it also check that we have
a hardware spinlock before freeing it - the core code reports an error
when freeing an invalid lock.
Suggested-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

Unlike other lock types hwspinlocks are optional and can be built
modular so we can't use them unconditionally in regmap so add a config
option that drivers that want to use hwspinlocks with regmap can select
which will ensure that hwspinlock is built in.
Signed-off-by: NMark Brown <broonie@kernel.org>

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

Most of the kernel-doc comments in regmap don't actually generate
correctly. This patch fixes up a few common issues, corrects some typos
and adds some missing argument descriptions.

The most common issues being using a : after the function name which
causes the short description to not render correctly and not separating
the long and short descriptions of the function. There are quite a few
instances of arguments not being described or given the wrong name as
well.

This patch doesn't fixup functions/structures that are currently missing
descriptions.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

To make the code clearer, use rb_entry() instead of container_of() to
deal with rbtree.
Signed-off-by: NGeliang Tang <geliangtang@gmail.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Commit 815806e3 ("regmap: drop cache if the bus transfer error")
added a call to regcache_drop_region() to error path in
_regmap_raw_write(). However that path runs with regmap lock taken,
and regcache_drop_region() tries to re-take it, causing a deadlock.
Fix that by calling map->cache_ops->drop() directly.
Signed-off-by: NNikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This with the longer read and write masks allow supporting more
exotic devices. For example a little endian SPI device:

static const struct regmap_config foo_regmap_config = {
	.reg_bits = 16,
	.reg_stride = 4,
	.val_bits = 16,
	.write_flag_mask = 0x8000,
	.reg_format_endian = REGMAP_ENDIAN_LITTLE,
	.val_format_endian = REGMAP_ENDIAN_LITTLE,
	...
};
Signed-off-by: NTony Lindgren <tony@atomide.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

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

regmap_write
->_regmap_raw_write
-->regcache_write first and than use map->bus->write to wirte i2c or spi
But if the i2c or spi transfer failed, But the cache is updated, So if I use
regmap_read will get the cache data which is not the real register value.
Signed-off-by: NElaine Zhang <zhangqing@rock-chips.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

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

When doing a bulk writes from a device which lacks raw I/O support we
fall back to doing register at a time reads but we still use the raw
formatters in order to render the data into the word size used by the
device (since bulk reads still operate on the device word size rather
than unsigned ints).  This means that devices without raw formatting
such as those that provide reg_read() are not supported.  Provide
handling for them by copying the values read into native endian values
of the appropriate size.

This complements commit d5b98eb1 ("regmap: Support bulk reads for
devices without raw formatting").
Signed-off-by: NChen-Yu Tsai <wens@csie.org>
Signed-off-by: NMark Brown <broonie@kernel.org>

commit 23b92e4cf5fd ("regmap: remove regmap_write_bits()")
removed regmap_write_bits(), but MFD driver was using it.
So, commit e30fccd6771d ("regmap: Keep regmap_write_bits()")
turns out it, but it is using original style.
This patch uses regmap_update_bits_base() for regmap_write_bits()
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch merges regmap_fields_update_bits() into macro
by using regmap_field_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch merges regmap_fields_write() into macro
by using regmap_fields_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch adds new regmap_fields_update_bits_base() which is using
regmap_update_bits_base().
Current regmap_fields_xxx() can be merged into it by macro.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch merges regmap_field_update_bits() into macro
by using regmap_field_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch merges regmap_field_write() into macro
by using regmap_field_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

This patch adds new regmap_field_update_bits_base() which is using
regmap_update_bits_base().
Current regmap_field_xxx() can be merged into it by macro.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current regmap has many similar update functions like below,
but the difference is very few.
	regmap_update_bits()
	regmap_update_bits_async()
	regmap_update_bits_check()
	regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits_check_async() into macro
by using regmap_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current regmap has many similar update functions like below,
but the difference is very few.
	regmap_update_bits()
	regmap_update_bits_async()
	regmap_update_bits_check()
	regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits_check() into macro
by using regmap_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current regmap has many similar update functions like below,
but the difference is very few.
	regmap_update_bits()
	regmap_update_bits_async()
	regmap_update_bits_check()
	regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits_async() into macro
by using regmap_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current regmap has many similar update functions like below,
but the difference is very few.
	regmap_update_bits()
	regmap_update_bits_async()
	regmap_update_bits_check()
	regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch merges regmap_update_bits() into macro
by using regmap_update_bits_base().
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>

Current regmap has many similar update functions like below,
but the difference is very few.
	regmap_update_bits()
	regmap_update_bits_async()
	regmap_update_bits_check()
	regmap_update_bits_check_async()
Furthermore, we can add *force* write option too in the future.

This patch adds new regmap_update_bits_base() which is feature
merged function. Above functions can be merged into it by macro.
Signed-off-by: NKuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: NMark Brown <broonie@kernel.org>