Rename the internal __reset_control_get/put functions to
__reset_control_get/put_internal and add an exported
__reset_control_get equivalent to __of_reset_control_get
that takes a struct device parameter.
This avoids the confusing call to __of_reset_control_get in
the non-DT case and fixes the devm_reset_control_get_optional
function to return NULL if RESET_CONTROLLER is enabled but
dev->of_node == NULL.

Fixes: bb475230 ("reset: make optional functions really optional")
Reported-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: NAndy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

When RESET_CONTROLLER is not enabled, the optional reset_control_get
stubs should now also return NULL.

Since it is now valid for reset_control_assert/deassert/reset/status/put
to be called unconditionally, with NULL as an argument for optional
resets, the stubs are not allowed to warn anymore.

Fixes: bb475230 ("reset: make optional functions really optional")
Reported-by: NAndrzej Hajda <a.hajda@samsung.com>
Tested-by: NAndrzej Hajda <a.hajda@samsung.com>
Reviewed-by: NAndrzej Hajda <a.hajda@samsung.com>
Cc: Ramiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The *_get_optional_* functions weren't really optional so this patch
makes them really optional.

These *_get_optional_* functions will now return NULL instead of an error
if no matching reset phandle is found in the DT, and all the
reset_control_* functions now accept NULL rstc pointers.
Signed-off-by: NRamiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Since the new parameter being added is going to be a bool this patch
changes the shared flag from int to bool to match the new parameter.
Signed-off-by: NRamiro Oliveira <Ramiro.Oliveira@synopsys.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Standardise the way inline functions:

  devm_reset_control_get_shared_by_index
  devm_reset_control_get_exclusive_by_index

... are formatted.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Consumers need to be able to specify whether they are requesting an
'exclusive' or 'shared' reset line no matter which API (of_*, devm_*,
etc) they are using.  This change allows users of the optional_* API
in particular to specify that their request is for a 'shared' line.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Consumers need to be able to specify whether they are requesting an
'exclusive' or 'shared' reset line no matter which API (of_*, devm_*,
etc) they are using.  This change allows users of the of_* API in
particular to specify that their request is for a 'shared' line.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Phasing out generic reset line requests enables us to make some better
decisions on when and how to (de)assert said lines.  If an 'exclusive'
line is requested, we know a device *requires* a reset and that it's
preferable to act upon a request right away.  However, if a 'shared'
reset line is requested, we can reasonably assume sure that placing a
device into reset isn't a hard requirement, but probably a measure to
save power and is thus able to cope with not being asserted if another
device is still in use.

In order allow gentle adoption and not to forcing all consumers to
move to the API immediately, causing administration headache between
subsystems, this patch adds some temporary stand-in shim-calls.  This
will ease the burden at merge time and allow subsystems to migrate over
to the new API in a more realistic time-frame.
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

We're about to split the current API into two, where consumers will
be forced to be explicit when requesting reset lines.  The choice
will be to either the call the *_exclusive or *_shared variant
depending on whether they can actually tolorate not being asserted
when that request is made.

The new API will look like this once reorded and complete:

  reset_control_get_exclusive()
  reset_control_get_shared()
  reset_control_get_optional_exclusive()
  reset_control_get_optional_shared()
  of_reset_control_get_exclusive()
  of_reset_control_get_shared()
  of_reset_control_get_exclusive_by_index()
  of_reset_control_get_shared_by_index()
  devm_reset_control_get_exclusive()
  devm_reset_control_get_shared()
  devm_reset_control_get_optional_exclusive()
  devm_reset_control_get_optional_shared()
  devm_reset_control_get_exclusive_by_index()
  devm_reset_control_get_shared_by_index()
Signed-off-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

Prior to commit 6c96f05c ("reset: Make [of_]reset_control_get[_foo]
functions wrappers"), the "optional" functions returned -ENOTSUPP when
CONFIG_RESET_CONTROLLER was not set.

Revert back to the old behavior by changing the new
__devm_reset_control_get() and __of_reset_control_get() functions to
return ERR_PTR(-ENOTSUPP) when compiled without CONFIG_RESET_CONTROLLER.

Otherwise they will return -EINVAL causing users to think that an error
occurred when CONFIG_RESET_CONTROLLER is not set.

Fixes: 6c96f05c ("reset: Make [of_]reset_control_get[_foo] functions wrappers")
Signed-off-by: NJohn Youn <johnyoun@synopsys.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

The Mediatek's thermal driver fails to compile when the RESET_CONTROLLER
option is not set. Logically, as the driver depends on this option to compile,
the Kconfig should select it but actually that is not correct because the
Kconfig provides also the COMPILE_TEST to increase the compile test coverage.

By providing the missing 'device_reset' stub for the driver in reset.h, that
let the kernel to compile on different platforms with the Mediatek thermal
driver enabled with the COMPILE_TEST option.
Signed-off-by: NDaniel Lezcano <daniel.lezcano@linaro.org>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

In some SoCs some hw-blocks share a reset control. Add support for this
setup by adding new:

reset_control_get_shared()
devm_reset_control_get_shared()
devm_reset_control_get_shared_by_index()

methods to get a reset_control. Note that this patch omits adding of_
variants, if these are needed later they can be easily added.

This patch also changes the behavior of the existing exclusive
reset_control_get() variants, if these are now called more then once
for the same reset_control they will return -EBUSY. To catch existing
drivers triggering this error (there should not be any) a WARN_ON(1)
is added in this path.

When a reset_control is shared, the behavior of reset_control_assert /
deassert is changed, for shared reset_controls these will work like the
clock-enable/disable and regulator-on/off functions. They will keep a
deassert_count, and only (re-)assert the reset after reset_control_assert
has been called as many times as reset_control_deassert was called.

Calling reset_control_assert without first calling reset_control_deassert
is not allowed on a shared reset control. Calling reset_control_reset is
also not allowed on a shared reset control.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

With both the regular, _by_index and _optional variants we already have
quite a few variants of [of_]reset_control_get[_foo], the upcoming
addition of shared reset lines support makes this worse.

This commit changes all the variants into wrappers around common core
functions. For completeness sake this commit also adds a new
devm_get_reset_control_by_index wrapper.
Signed-off-by: NHans de Goede <hdegoede@redhat.com>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>

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>

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>

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>