Re: [PATCH v11 2/3] dt-bindings: pinctrl: mt8195: Add mediatek,drive-strength-adv property

From: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
To: Tinghan Shen <tinghan.shen@mediatek.com>,
	Rob Herring <robh+dt@kernel.org>,
	Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>,
	Linus Walleij <linus.walleij@linaro.org>,
	Matthias Brugger <matthias.bgg@gmail.com>,
	Bartosz Golaszewski <bgolaszewski@baylibre.com>,
	Sean Wang <sean.wang@mediatek.com>
Cc: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org,
	linux-gpio@vger.kernel.org, linux-arm-kernel@lists.infradead.org,
	linux-mediatek@lists.infradead.org,
	Project_Global_Chrome_Upstream_Group@mediatek.com,
	ryder.lee@kernel.org, wenst@chromium.org,
	chunfeng.yun@mediatek.com
Subject: Re: [PATCH v11 2/3] dt-bindings: pinctrl: mt8195: Add mediatek,drive-strength-adv property
Date: Wed, 16 Feb 2022 12:44:02 +0100	[thread overview]
Message-ID: <cc5e7f4b-8a70-01a3-3219-b6b3c825504d@collabora.com> (raw)
In-Reply-To: <20220216113131.13145-3-tinghan.shen@mediatek.com>

Il 16/02/22 12:31, Tinghan Shen ha scritto:
> Extend driving support for I2C pins on SoC mt8195.
> This property is already documented in mediatek,mt8183-pinctrl.yaml.
> 
> Signed-off-by: Tinghan Shen <tinghan.shen@mediatek.com>
> Reviewed-by: Rob Herring <robh@kernel.org>

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>

> ---
>   .../bindings/pinctrl/pinctrl-mt8195.yaml      | 35 +++++++++++++++++++
>   1 file changed, 35 insertions(+)
> 
> diff --git a/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8195.yaml b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8195.yaml
> index 8299662c2c09..c5b755514c46 100644
> --- a/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8195.yaml
> +++ b/Documentation/devicetree/bindings/pinctrl/pinctrl-mt8195.yaml
> @@ -98,6 +98,32 @@ patternProperties:
>             drive-strength:
>               enum: [2, 4, 6, 8, 10, 12, 14, 16]
>   
> +          mediatek,drive-strength-adv:
> +            description: |
> +              Describe the specific driving setup property.
> +              For I2C pins, the existing generic driving setup can only support
> +              2/4/6/8/10/12/14/16mA driving. But in specific driving setup, they
> +              can support 0.125/0.25/0.5/1mA adjustment. If we enable specific
> +              driving setup, the existing generic setup will be disabled.
> +              The specific driving setup is controlled by E1E0EN.
> +              When E1=0/E0=0, the strength is 0.125mA.
> +              When E1=0/E0=1, the strength is 0.25mA.
> +              When E1=1/E0=0, the strength is 0.5mA.
> +              When E1=1/E0=1, the strength is 1mA.
> +              EN is used to enable or disable the specific driving setup.
> +              Valid arguments are described as below:
> +              0: (E1, E0, EN) = (0, 0, 0)
> +              1: (E1, E0, EN) = (0, 0, 1)
> +              2: (E1, E0, EN) = (0, 1, 0)
> +              3: (E1, E0, EN) = (0, 1, 1)
> +              4: (E1, E0, EN) = (1, 0, 0)
> +              5: (E1, E0, EN) = (1, 0, 1)
> +              6: (E1, E0, EN) = (1, 1, 0)
> +              7: (E1, E0, EN) = (1, 1, 1)
> +              So the valid arguments are from 0 to 7.
> +            $ref: /schemas/types.yaml#/definitions/uint32
> +            enum: [0, 1, 2, 3, 4, 5, 6, 7]
> +
>             bias-pull-down:
>               oneOf:
>                 - type: boolean
> @@ -270,4 +296,13 @@ examples:
>             bias-pull-down;
>           };
>         };
> +
> +      i2c0-pins {
> +        pins {
> +          pinmux = <PINMUX_GPIO8__FUNC_SDA0>,
> +                   <PINMUX_GPIO9__FUNC_SCL0>;
> +          bias-disable;
> +          mediatek,drive-strength-adv = <7>;
> +        };
> +      };
>       };

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