regulator: Add driver for gpio-controlled regulators
authorHeiko Stübner <heiko@sntech.de>
Wed, 5 Oct 2011 10:27:05 +0000 (12:27 +0200)
committerRohan Somvanshi <rsomvanshi@nvidia.com>
Thu, 19 Jan 2012 18:29:01 +0000 (10:29 -0800)
commit8501e757c02e6d30d775e1d4fb4da3ae1bee74bc
tree9338eb32c7eb62522bb62166db93780975c87e7f
parent6887f3b6246048d73132a138003af11288325ec2
regulator: Add driver for gpio-controlled regulators

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: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
(cherry picked from commit 3f0292ae8bb100cc8f96106a3de277df48134887)

regulator: Add module.h include to gpio-regulator

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
(cherry picked from commit ecc37edf7b670616a9dc78a0bdd4911a22d551ec)

regulator: Fix compile break due to missing arguments to regulator_register

The commit 2c043bcbf287 ("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: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
(cherry picked from commit 156843470c4b9ea9698cc245d2cff769b3784088)
Change-Id: I912886aae825ca440f4ad3e7a33fe4e84bde4e1b
Reviewed-on: http://git-master/r/74924
Reviewed-by: Laxman Dewangan <ldewangan@nvidia.com>
Tested-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-on: http://git-master/r/75547
Reviewed-by: Varun Wadekar <vwadekar@nvidia.com>
Tested-by: Varun Wadekar <vwadekar@nvidia.com>
drivers/regulator/Kconfig
drivers/regulator/Makefile
drivers/regulator/gpio-regulator.c [new file with mode: 0644]
include/linux/regulator/gpio-regulator.h [new file with mode: 0644]