Rather than adding new arguments to regulator_register() every time we
want to add a new bit of dynamic information at runtime change the function
to take these via a struct. By doing this we avoid needing to do further
changes like the recent addition of device tree support which required each
regulator driver to be updated to take an additional parameter.

The regulator_desc which should (mostly) be static data is still passed
separately as most drivers are able to configure this statically at build
time.
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

There's some other allocations but they're not so trivial as they use
kmemdup() and kstrdup().
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Do not assume the gpio regulator states map is sorted in any order.
This patch ensures we always set the smallest voltage/current that falls within
the specified range.
Signed-off-by: NAxel Lin <axel.lin@gmail.com>
Acked-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

The commit 2c043bcb ("regulator: pass additional of_node to
regulator_register()") caused a compile break because it missed
updating the regulator_register() call in gpio-regulator.c with
the additional parameter (NULL).

The compile break as reported by Stephen Rothwell with the
x86_64 allmodconfig looked like this

drivers/regulator/gpio-regulator.c: In function 'gpio_regulator_probe':
drivers/regulator/gpio-regulator.c:287:8: error: too few arguments to function 'regulator_register'
include/linux/regulator/driver.h:215:23: note: declared here
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NRajendra Nayak <rnayak@ti.com>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>

This patch adds support for regulators that can be controlled via gpios.

Examples for such regulators are the TI-tps65024x voltage regulators
with 4 fixed and 1 runtime-switchable voltage regulators
or the TI-bq240XX charger regulators.

The number of controlling gpios is not limited, the mapping between
voltage/current and target gpio state is done via the states map
and the driver can be used for either voltage or current regulators.

A mapping for a regulator with two GPIOs could look like:

gpios = {
	{ .gpio = GPIO1, .flags = GPIOF_OUT_INIT_HIGH, .label = "gpio name 1" },
	{ .gpio = GPIO2, .flags = GPIOF_OUT_INIT_LOW,  .label = "gpio name 2" },
}

The flags element of the gpios array determines the initial state of
the gpio, set during probe. The initial state of the regulator is also
calculated from these values

states = {
	{ .value = volt_or_cur1, .gpios = (0 << 1) | (0 << 0) },
	{ .value = volt_or_cur2, .gpios = (0 << 1) | (1 << 0) },
	{ .value = volt_or_cur3, .gpios = (1 << 1) | (0 << 0) },
	{ .value = volt_or_cur4, .gpios = (1 << 1) | (1 << 0) },
}

The target-state for the n-th gpio is determined by the n-th bit
in the bitfield of the target-value.
Signed-off-by: NHeiko Stuebner <heiko@sntech.de>
Signed-off-by: NMark Brown <broonie@opensource.wolfsonmicro.com>