linux-kernel - Re: [PATCH 06/14] dt-bindings: pinctrl: qcom: tlmm should use output-disable, not input-enable

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Message-ID: <58ba3b6f-578f-0bdd-13cd-980eda28d2c7@linaro.org>
Date:   Mon, 27 Mar 2023 09:21:38 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Douglas Anderson <dianders@...omium.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Mark Brown <broonie@...nel.org>,
        Linus Walleij <linus.walleij@...aro.org>
Cc:     Matthias Kaehlcke <mka@...omium.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        linux-gpio@...r.kernel.org, Stephen Boyd <swboyd@...omium.org>,
        devicetree@...r.kernel.org, linux-arm-msm@...r.kernel.org,
        linux-spi@...r.kernel.org, Andy Gross <agross@...nel.org>,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH 06/14] dt-bindings: pinctrl: qcom: tlmm should use
 output-disable, not input-enable

On 23/03/2023 18:30, Douglas Anderson wrote:
> As evidenced by the Qualcomm TLMM Linux driver, the TLMM IP block in
> Qualcomm SoCs has a bit to enable/disable the output for a pin that's
> configured as a GPIO but _not_ a bit to enable/disable an input
> buffer. Current device trees that are specifying "input-enable" for
> pins managed by TLMM are either doing so needlessly or are using it to
> mean "output-disable".
> 
> Presumably the current convention of using "input-enable" to mean
> "output-disable" stems from the fact that "output-disable" is a "new"
> property from 2017. It was introduced in commit 425562429d4f
> ("pinctrl: generic: Add output-enable property"). The "input-enable"
> handling in Qualcomm drivers is from 2015 introduced in commit
> 407f5e392f9c ("pinctrl: qcom: handle input-enable pinconf property").
> 
> Given that there's no other use for "input-enable" for TLMM, we can
> still handle old device trees in code, but let's encourage people to
> move to the proper / documented property by updating the bindings.
> 


Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>

Best regards,
Krzysztof