Load switches are modeled as regulators but they just provide
the voltage of their parent input supply. So, the drivers for
these switches usually neither provide a .list_voltage handler
not set a .n_voltages count. But there is code in the kernel
that assumes that all regulators should be able to provide this
information (e.g: cpufreq and mmc subsystems).

If the voltage count and list are not available for a regulator
and it has a parent input supply, then use the parent values.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@linaro.org>

Load switches are modeled as regulators but they just provide
the voltage of their parent input supply. So the drivers for
these switches usually don't provide a .get_voltage function
handler but there is code in the kernel that assumes that all
regulators should be able to provide its current voltage rail.

So, if the output voltage for a regulator is not available and
it has a parent supply, then pass the voltage of its parent.

Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk>
Signed-off-by: Mark Brown <broonie@linaro.org>

Add helper functions that allow regulator consumers to obtain low-level
details about the regulator hardware, like the voltage selector register
address and such. These details can be useful when configuring hardware
or firmware that want to do low-level access to regulators, with no
involvement from the kernel.

The use-case for Tegra is a voltage-controlled oscillator clocksource
which has control logic to change the supply voltage via I2C to achieve
a desired output clock rate.

Signed-off-by: Tuomas Tynkkynen <ttynkkynen@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Convert the regulator GPIO handling to use a gpio descriptor rather than
numbers.  This allows us to revise the interfaces to permit all GPIOs
to be used with the regulator core.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Mark Brown <broonie@linaro.org>

With commit 064d5cd110f94ce41ca5681dcda8b77fa63d5b95
(regulator: core: Fix the init of DT defined fixed regulators)
We ensure that regulator must be capable of providing it's current
voltage when constraints are used, however adding the return value in
the print is a little more informative to explain the nature of the
failure involved.

So, instead of providing message such as:
smps9: failed to get the current voltage

having error value added to the message such as:
smps9: failed to get the current voltage(-22)

is a little more informative for debugging the error.

Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

When a regulator is defined using DT and it has a single voltage the
regulator init always tries to apply this voltage. However it fails if
the regulator isn't settable because it is using an internal low level
function. To overcome this we now first query the regulator and only
set it if needed.

Signed-off-by: Alban Bedel <alban.bedel@avionic-design.de>
Signed-off-by: Mark Brown <broonie@linaro.org>

regulator_init_complete does a scan of regulators which dont have
always-on or consumers are automatically disabled as being unused.
However, with deferred probing, late_initcall() is too soon to
declare a regulator as unused as the regulator itself might not
have registered due to defferal - Example: A regulator deffered due
to i2bus not available which in turn is deffered due to pinctrl
availability.

Since deferred probing is done in late_initcall(), do the cleanup of
unused regulators by regulator_init_complete in late_initcall_sync
instead of late_initcall.

Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Markus Pargmann <mpa@pengutronix.de>
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>
[nm@ti.com: minor rewording]
Signed-off-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Mark Brown <broonie@linaro.org>