Add regulator_get_linear_step(), which returns the voltage step size
between VSEL values for linear regulators.  This is intended for use
by regulator consumers which build their own voltage-to-VSEL tables.

Signed-off-by: Paul Walmsley <pwalmsley@nvidia.com>
Reviewed-by: Andrew Chew <achew@nvidia.com>
Cc: Matthew Longnecker <mlongnecker@nvidia.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

Add a couple kernel-doc lines to get rid of kernel-doc generation
warnings, no functional change.

Signed-off-by: Robert P. J. Day <rpjday@crashcourse.ca>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

A lot of regulator hardware has ascendant voltage list.
This patch adds regulator_map_voltage_ascend() and export it.

Drivers that have ascendant voltage list can use this as their map_voltage()
operation, this is more efficient than default regulator_map_voltage_iterate()
function.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

commit 6d191a5fc7a969d972f1681e1c23781aecb06a61
(regulator: core: Don't defer probe if there's no DT binding for a supply)

Attempted to differentiate between regulator_get() with an actual
DT binding for the supply and when there is none to avoid unnecessary
deferal.
However, ret value supplied by regulator_dev_lookup() is being
ignored by regulator_get(). So, exit with the appropriate return value.

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