Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <58ba3b6f-578f-0bdd-13cd-980eda28d2c7@linaro.org>
Date:   Mon, 27 Mar 2023 09:21:38 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.9.0
Subject: Re: [PATCH 06/14] dt-bindings: pinctrl: qcom: tlmm should use
 output-disable, not input-enable
To:     Douglas Anderson <dianders@chromium.org>,
        Bjorn Andersson <andersson@kernel.org>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        Mark Brown <broonie@kernel.org>,
        Linus Walleij <linus.walleij@linaro.org>
Cc:     Matthias Kaehlcke <mka@chromium.org>,
        Konrad Dybcio <konrad.dybcio@linaro.org>,
        linux-gpio@vger.kernel.org, Stephen Boyd <swboyd@chromium.org>,
        devicetree@vger.kernel.org, linux-arm-msm@vger.kernel.org,
        linux-spi@vger.kernel.org, Andy Gross <agross@kernel.org>,
        linux-kernel@vger.kernel.org
References: <20230323173019.3706069-1-dianders@chromium.org>
 <20230323102605.6.I291ce0ba2c6ea80b341659c4f75a567a76dd7ca6@changeid>
Content-Language: en-US
From:   Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
In-Reply-To: <20230323102605.6.I291ce0ba2c6ea80b341659c4f75a567a76dd7ca6@changeid>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit
Precedence: bulk

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@linaro.org>

Best regards,
Krzysztof