Add devres helpers

 - devm_reset_control_bulk_get_exclusive_deasserted
 - devm_reset_control_bulk_get_optional_exclusive_deasserted
 - devm_reset_control_bulk_get_optional_shared_deasserted
 - devm_reset_control_bulk_get_shared_deasserted
 - devm_reset_control_get_exclusive_deasserted
 - devm_reset_control_get_optional_exclusive_deasserted
 - devm_reset_control_get_optional_shared_deasserted
 - devm_reset_control_get_shared_deasserted

to request and immediately deassert reset controls. During cleanup,
reset_control_assert() will be called automatically on the returned
reset controls.

Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240925-reset-get-deasserted-v2-2-b3601bbd0458@pengutronix.de
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Introduce enum reset_control_flags and replace the list of boolean
parameters to the internal reset_control_get functions with a single
flags parameter, before adding more boolean options.

The separate boolean parameters have been shown to be error prone in
the past. See for example commit a57f68ddc886 ("reset: Fix devm bulk
optional exclusive control getter").

Acked-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240925-reset-get-deasserted-v2-1-b3601bbd0458@pengutronix.de
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Since the rcdev structure is allocated by the reset controller drivers
themselves, they need to exists as long as there is a consumer. A call to
module_get() is already existing but that does not work when using
device-tree overlays. In order to guarantee that the underlying reset
controller device does not vanish while using it, add a get_device() call
when retrieving a reset control from a reset controller device and a
put_device() when releasing that control.

Signed-off-by: Clément Léger <clement.leger@bootlin.com>
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Link: https://lore.kernel.org/r/20240808154658.247873-8-herve.codina@bootlin.com
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Simplify error handling (less gotos) over locks with guard().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://lore.kernel.org/r/20240825-reset-cleanup-scoped-v1-3-03f6d834f8c0@linaro.org
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Devices sharing a reset GPIO could use the reset framework for
coordinated handling of that shared GPIO line.  We have several cases of
such needs, at least for Devicetree-based platforms.

If Devicetree-based device requests a reset line, while "resets"
Devicetree property is missing but there is a "reset-gpios" one,
instantiate a new "reset-gpio" platform device which will handle such
reset line.  This allows seamless handling of such shared reset-gpios
without need of changing Devicetree binding [1].

To avoid creating multiple "reset-gpio" platform devices, store the
Devicetree "reset-gpios" GPIO specifiers used for new devices on a
linked list.  Later such Devicetree GPIO specifier (phandle to GPIO
controller, GPIO number and GPIO flags) is used to check if reset
controller for given GPIO was already registered.

If two devices have conflicting "reset-gpios" property, e.g. with
different ACTIVE_xxx flags, this would allow to spawn two separate
"reset-gpio" devices, where the second would fail probing on busy GPIO
request.

Link: https://lore.kernel.org/all/YXi5CUCEi7YmNxXM@robh.at.kernel.org/ [1]
Cc: Bartosz Golaszewski <brgl@bgdev.pl>
Cc: Chris Packham <chris.packham@alliedtelesis.co.nz>
Cc: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Acked-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240129115216.96479-5-krzysztof.kozlowski@linaro.org
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

When obtaining one or more optional resets, non-existent resets are
stored as NULL pointers, and all related error and cleanup paths need to
take this into account.

Currently only reset_control_put() and reset_control_bulk_put()
get this right.  All of __reset_control_bulk_get(),
of_reset_control_array_get(), and reset_control_array_put() lack the
proper checking, causing NULL pointer dereferences on failure or
release.

Fix this by moving the existing check from reset_control_bulk_put() to
__reset_control_put_internal(), so it applies to all callers.
The double check in reset_control_put() doesn't hurt.

Fixes: 17c82e206d2a3cd8 ("reset: Add APIs to manage array of resets")
Fixes: 48d71395896d54ee ("reset: Add reset_control_bulk API")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://lore.kernel.org/r/2440edae7ca8534628cdbaf559ded288f2998178.1701276806.git.geert+renesas@glider.be
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct reset_control_array.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230922175229.work.838-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

Some of the IO devices like I2C or SPI require reset at runtime to
recover from an error condition without changing the power state of
the system. Added check for ACPI handle and a call to method '__RST'
if supported. Devices using device tree method are unaffected by this.

Signed-off-by: Krishna Yarlagadda <kyarlagadda@nvidia.com>
[p.zabel@pengutronix.de: wrap in #ifdef CONFIG_ACPI due to missing stubs]
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Link: https://lore.kernel.org/r/20220307135626.16673-1-kyarlagadda@nvidia.com

Abort instead of returning a new reset control for a reset controller
device that is going to have its module unloaded.

Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 61fc41317666 ("reset: Add reset controller API")
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Link: https://lore.kernel.org/r/20210607082615.15160-1-p.zabel@pengutronix.de
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>

Fixes checkpatch issues:

  CHECK: Alignment should match open parenthesis
  #87: FILE: drivers/reset/core.c:87:
  +static int of_reset_simple_xlate(struct reset_controller_dev *rcdev,
  +			  const struct of_phandle_args *reset_spec)

  CHECK: Lines should not end with a '('
  #540: FILE: drivers/reset/core.c:540:
  +static struct reset_control *__reset_control_get_internal(

  CHECK: Alignment should match open parenthesis
  #603: FILE: drivers/reset/core.c:603:
  +struct reset_control *__of_reset_control_get(struct device_node *node,
  +				     const char *id, int index, bool shared,

  CHECK: Alignment should match open parenthesis
  #781: FILE: drivers/reset/core.c:781:
  +struct reset_control *__devm_reset_control_get(struct device *dev,
  +				     const char *id, int index, bool shared,

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>