ENOSYS is reserved to report invalid syscalls to userspace.
Consistently return ENOTSUPP to indicate that the driver doesn't support
the functionality or the reset framework is not enabled at all.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

When of_reset_control_get() is called without connection ID it returns
-ENOENT when the 'resets' property doesn't exists or is an empty entry.
However when a connection ID is given it returns -EINVAL when the 'resets'
property doesn't exists or the requested name can't be found. This is
because the error code returned by of_property_match_string() is just
passed down as an index to of_parse_phandle_with_args(), which then
returns -EINVAL.

To get a consistent return value with both code paths we must return
-ENOENT when of_property_match_string() fails.
Signed-off-by: NAlban Bedel <albeu@free.fr>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Add of_reset_control_get_by_index() to allow the drivers to get reset
device without knowing its name.
Signed-off-by: NVince Hsu <vinceh@nvidia.com>
[jonathanh@nvidia.com: Updated stub function to return -ENOTSUPP instead
 of -ENOSYS which should only be used for system calls.]
Signed-off-by: NJon Hunter <jonathanh@nvidia.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>

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>

Mark function of_reset_simple_xlate() as static in core.c
because it is not used outside this file.
Also, remove functions devm_reset_control_put() and
devm_reset_control_match() because they are unused.

This eliminates the following warnings in core.c:
drivers/reset/core.c:46:5: warning: no previous prototype for ‘of_reset_simple_xlate’ [-Wmissing-prototypes]
drivers/reset/core.c:262:6: warning: no previous prototype for ‘devm_reset_control_put’ [-Wmissing-prototypes]
Signed-off-by: NRashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: NJosh Triplett <josh@joshtriplett.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

If the requested reset controller is not yet available, have reset_control_get
and device_reset return -EPROBE_DEFER so the driver can decide to request
probe deferral.
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NShawn Guo <shawn.guo@linaro.org>
Reviewed-by: NStephen Warren <swarren@nvidia.com>

"rstc" is NULL here and we should use "rcdev" instead of "rstc->rcdev".
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.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>