[PATCH v5 0/7] gpio: introduce a gpio driver for SCMI

[PATCH v5 0/7] gpio: introduce a gpio driver for SCMI

[Dan Carpenter]

This basically abandons my earlier attempts and goes back to Takahiro
Akashi's driver.  Here is the link to Takahiro's patchset:

https://lore.kernel.org/all/20231005025843.508689-1-takahiro.akashi@linaro.org/

v5: Addresses Andy's cleanups to the driver.
    Adrresses Krzysztof's comments about the dt spec file.
    And almost all the subsystem prefixes were wrong.

v4: Addressed Andy's comments about kernel-doc
    Addressed Rob's comments on the spec file

v3: Forward ported Takahiro's patches and added some fixes ups to make
    it work on current kernels.

AKASHI Takahiro (3):
  pinctrl: introduce pinctrl_gpio_get_config()
  gpio: dt-bindings: Add bindings for pinctrl based generic gpio driver
  gpio: gpio-by-pinctrl: add pinctrl based generic GPIO driver

Dan Carpenter (4):
  pinctrl: scmi: Add SCMI_PIN_INPUT_VALUE
  pinctrl: scmi: Delete PIN_CONFIG_OUTPUT_IMPEDANCE_OHMS support
  pinctrl: scmi: ignore PIN_CONFIG_PERSIST_STATE
  firmware: arm_scmi: Allow PINCTRL_REQUEST to return EOPNOTSUPP

 .../bindings/gpio/pin-control-gpio.yaml       |  59 ++++++++++
 drivers/firmware/arm_scmi/pinctrl.c           |   2 +
 drivers/gpio/Kconfig                          |  13 +++
 drivers/gpio/Makefile                         |   1 +
 drivers/gpio/gpio-by-pinctrl.c                | 101 ++++++++++++++++++
 drivers/pinctrl/core.c                        |  31 ++++++
 drivers/pinctrl/pinctrl-scmi.c                |  46 +++++---
 include/linux/pinctrl/consumer.h              |   9 ++
 8 files changed, 249 insertions(+), 13 deletions(-)
 create mode 100644 Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml
 create mode 100644 drivers/gpio/gpio-by-pinctrl.c

-- 
2.51.0

[PATCH v5 6/7] gpio: dt-bindings: Add bindings for pinctrl based generic gpio driver

[Dan Carpenter]

From: AKASHI Takahiro <takahiro.akashi@linaro.org>

Traditionally, firmware will provide a GPIO interface or a pin control
interface.  However, the SCMI protocol provides a generic pin control
interface and the GPIO support is built on top of that using the normal
pin control interfaces.  Potentially other firmware will adopt a
similar generic approach in the future.

Document how to configure the GPIO device.

Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Reviewed-by: Linus Walleij <linusw@kernel.org>
---
v5: Fix subsystem prefix
    Re-word the commit message
    I removed all references to the driver.  I also removed the
    reference to pin muxing because that's described in the pin control
    spec file.
    Fix 3 vs 4 typo in the example.
v4: Changed additionalProperties: true to false.
    Add gpio-line-names.
    Deleted one example.
    Add r-b tags
v3: Forward port and update

 .../bindings/gpio/pin-control-gpio.yaml       | 59 +++++++++++++++++++
 1 file changed, 59 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml

diff --git a/Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml b/Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml
new file mode 100644
index 000000000000..9d20b5f23cdc
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml
@@ -0,0 +1,59 @@
+# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/pin-control-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Pin control based generic GPIO controller
+
+description:
+  The pin control-based GPIO will facilitate a pin controller's ability
+  to drive electric lines high/low and other generic properties of a
+  pin controller to perform general-purpose one-bit binary I/O.
+
+maintainers:
+  - Dan Carpenter <dan.carpenter@linaro.og>
+
+properties:
+  compatible:
+    const: scmi-pinctrl-gpio
+
+  gpio-controller: true
+
+  "#gpio-cells":
+    const: 2
+
+  gpio-line-names: true
+
+  gpio-ranges: true
+
+  ngpios: true
+
+patternProperties:
+  "^.+-hog(-[0-9]+)?$":
+    type: object
+
+    required:
+      - gpio-hog
+
+required:
+  - compatible
+  - gpio-controller
+  - "#gpio-cells"
+  - gpio-ranges
+  - ngpios
+
+additionalProperties: false
+
+examples:
+  - |
+    gpio {
+        compatible = "scmi-pinctrl-gpio";
+        gpio-controller;
+        #gpio-cells = <2>;
+        ngpios = <4>;
+        gpio-line-names = "gpio_5_17", "gpio_5_20", "gpio_5_22", "gpio_2_1";
+        gpio-ranges = <&scmi_pinctrl 0 30 4>;
+        pinctrl-names = "default";
+        pinctrl-0 = <&keys_pins>;
+    };
-- 
2.51.0

Re: [PATCH v5 6/7] gpio: dt-bindings: Add bindings for pinctrl based generic gpio driver

[Krzysztof Kozlowski]

On Sat, 21 Mar 2026 13:13:57 +0300, Dan Carpenter <dan.carpenter@linaro.org> wrote:
> Traditionally, firmware will provide a GPIO interface or a pin control
> interface.  However, the SCMI protocol provides a generic pin control
> interface and the GPIO support is built on top of that using the normal
> pin control interfaces.  Potentially other firmware will adopt a
> similar generic approach in the future.
> 
> Document how to configure the GPIO device.
> 
> Signed-off-by: AKASHI Takahiro <takahiro.akashi@linaro.org>
> Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
> Reviewed-by: Linus Walleij <linusw@kernel.org>

Subject still did not improve. Drop driver.

A nit, subject: drop second/last, redundant "bindings". The
"dt-bindings" prefix is already stating that these are bindings.
See also:
https://elixir.bootlin.com/linux/v6.17-rc3/source/Documentation/devicetree/bindings/submitting-patches.rst#L18

>
>
> diff --git a/Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml b/Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml
> new file mode 100644
> index 000000000000..9d20b5f23cdc
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/gpio/pin-control-gpio.yaml
> @@ -0,0 +1,59 @@
> +# SPDX-License-Identifier: GPL-2.0-only OR BSD-2-Clause
> +%YAML 1.2
> +---
> +$id: http://devicetree.org/schemas/gpio/pin-control-gpio.yaml#
> +$schema: http://devicetree.org/meta-schemas/core.yaml#
> +
> +title: Pin control based generic GPIO controller
> +
> +description:
> +  The pin control-based GPIO will facilitate a pin controller's ability
> +  to drive electric lines high/low and other generic properties of a
> +  pin controller to perform general-purpose one-bit binary I/O.
> +
> +maintainers:
> +  - Dan Carpenter <dan.carpenter@linaro.og>

Typo, org.

Rest looks good, so with subject fix and above:


Best regards,
Krzysztof

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>

-- 
Krzysztof Kozlowski <krzk@kernel.org>

Re: [PATCH v5 0/7] gpio: introduce a gpio driver for SCMI

[Bartosz Golaszewski]

On Sat, Mar 21, 2026 at 11:13 AM Dan Carpenter <dan.carpenter@linaro.org> wrote:
>
> This basically abandons my earlier attempts and goes back to Takahiro
> Akashi's driver.  Here is the link to Takahiro's patchset:
>
> https://lore.kernel.org/all/20231005025843.508689-1-takahiro.akashi@linaro.org/
>
> v5: Addresses Andy's cleanups to the driver.
>     Adrresses Krzysztof's comments about the dt spec file.
>     And almost all the subsystem prefixes were wrong.
>
> v4: Addressed Andy's comments about kernel-doc
>     Addressed Rob's comments on the spec file
>
> v3: Forward ported Takahiro's patches and added some fixes ups to make
>     it work on current kernels.
>

Once ready, how should this go in? Immutable branch in pinctrl and
final two patches through GPIO tree?

Bart

Re: [PATCH v5 0/7] gpio: introduce a gpio driver for SCMI

[Linus Walleij]

On Mon, Mar 23, 2026 at 10:58 AM Bartosz Golaszewski <brgl@kernel.org> wrote:
> On Sat, Mar 21, 2026 at 11:13 AM Dan Carpenter <dan.carpenter@linaro.org> wrote:
> >
> > This basically abandons my earlier attempts and goes back to Takahiro
> > Akashi's driver.  Here is the link to Takahiro's patchset:
> >
> > https://lore.kernel.org/all/20231005025843.508689-1-takahiro.akashi@linaro.org/
> >
> > v5: Addresses Andy's cleanups to the driver.
> >     Adrresses Krzysztof's comments about the dt spec file.
> >     And almost all the subsystem prefixes were wrong.
> >
> > v4: Addressed Andy's comments about kernel-doc
> >     Addressed Rob's comments on the spec file
> >
> > v3: Forward ported Takahiro's patches and added some fixes ups to make
> >     it work on current kernels.
>
> Once ready, how should this go in? Immutable branch in pinctrl and
> final two patches through GPIO tree?

Sounds like a plan, let's do that.

Yours,
Linus Walleij