So the drivers can be compiled with CONFIG_RESET_CONTROLLER disabled.
Signed-off-by: NAxel Lin <axel.lin@ingics.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

There are cases where a system will want to read a reset status bit before
doing any other toggling. Add a reset_control_status helper function to the
reset controller API.
Signed-off-by: NDinh Nguyen <dinguyen@opensource.altera.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

of_reset_control_get is not declared static in drivers/reset/core.c, which
is correct as we want to use it elsewhere too. But it does not have a
protype declared anywhere under include/linux. Add a prototype / stub for it
to linux/reset.h to fix this.
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

This patch adds device_reset_optional and (devm_)reset_control_get_optional
variants that drivers can use to indicate they can function without control
over the reset line. For those functions, stubs are added so the drivers can
be compiled with CONFIG_RESET_CONTROLLER disabled.
Also, device_reset is annotated with __must_check. Drivers ignoring the return
value should use device_reset_optional instead.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: NMarek Vasut <marex@denx.de>
Acked-by: NWolfram Sang <wsa@the-dreams.de>

In some cases, you might need to deassert from reset an hardware block that
doesn't associated to a struct device (CPUs, timers, etc.).

Add a small helper to retrieve the reset controller from the device tree
without the need to pass a struct device.
Signed-off-by: NMaxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

This adds a simple API for devices to request being reset
by separate reset controller hardware and implements the
reset signal device tree binding.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: NStephen Warren <swarren@nvidia.com>
Reviewed-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-by: NMarek Vasut <marex@denx.de>
Reviewed-by: NPavel Machek <pavel@ucw.cz>