The regulator framework maintains a list of consumer regulators
for a regulator device and protects it from concurrent access using
the regulator device's mutex lock.

In the case of regulator_put() the consumer is removed and regulator
device's parameters are updated without holding the regulator device's
mutex. This would lead to a race condition between the regulator_put()
and any function which traverses the consumer list or modifies regulator
device's parameters.
Fix this race condition by holding the regulator device's mutex in case
of regulator_put.

Signed-off-by: Ashay Jaiswal <ashayj@codeaurora.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: stable@vger.kernel.org

After freeing pin from regulator_ena_gpio_free, loop can access
the pin. So this patch fixes not to access pin after freeing.

Signed-off-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Add a PRE_DISABLE notification so that consumers can use a
notifier to run any steps required to prepare for the
regulator being switched off. Since the regulator disable
can fail an abort notification is also added.

Signed-off-by: Richard Fitzgerald <rf@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

Some systems have very large numbers of regulators so the constraint
logging done at startup can end up being a very big part of the boot
output which is both verbose and slows things down if the console is
a serial console. Lower to dev_dbg() instead, we may want to provide
a boot parameter to raise this in future but for now people can edit
the source.

Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>

Most drivers do not set the ena_gpio field of struct regulator_config
before passing it to the regulator core. This is fine as long as the
gpio identifier that is passed is a positive integer. But the gpio
identifier 0 is also valid. So we are not able to decide wether we got a
real gpio identifier or not based on a 0 in ena_gpio.

To be able to decide if it is a valid gpio that got passed, this patch
adds a ena_gpio_initialized field that should be set if was initialized
with a correct value, either a gpio >= 0 or a negative error number. The
core then checks if ena_gpio or ena_gpio_initialized before handling it
as a gpio. This way we maintain backwards compatibility and fix the
behaviour for gpio number 0.

Signed-off-by: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Mark Brown <broonie@kernel.org>

Currently regulator drivers which support DT all repeat very similar code
to supply a list of known regulator identifiers to be matched with DT,
convert that to platform data which is then matched up with the regulators
as they are registered. This is both fiddly to get right and for devices
which can use the standard helpers to provide their operations is the main
source of code in the driver.

Since this code is essentially identical for most drivers we can factor it
out into the core, moving the identifiers in the match table into the
regulator descriptors and also allowing drivers to pass in the name of the
subnode to search. When a driver provides an of_match string for the
regulator the core will attempt to use that to obtain init_data, allowing
the driver to remove all explicit code for DT parsing and simply provide
data instead.

The current code leaks the phandles for the child nodes, this will be
addressed incrementally and makes no practical difference for FDT anyway
as the DT data structures are never freed.

Signed-off-by: Mark Brown <broonie@linaro.org>