From mboxrd@z Thu Jan 1 00:00:00 1970 From: Archit Taneja Subject: Re: [PATCH v2 2/4] drm/msm/hdmi: Clean up HDMI gpio DT bindings Date: Tue, 13 Sep 2016 18:45:58 +0530 Message-ID: <57D7FC0E.6030209@codeaurora.org> References: <1467957354-7620-1-git-send-email-architt@codeaurora.org> <1472737015-29382-1-git-send-email-architt@codeaurora.org> <1472737015-29382-3-git-send-email-architt@codeaurora.org> <20160912131914.GA15499@rob-hp-laptop> <57D7A6CD.60803@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <57D7A6CD.60803@codeaurora.org> Sender: linux-arm-msm-owner@vger.kernel.org To: Rob Herring , robdclark@gmail.com Cc: andy.gross@linaro.org, linux-arm-msm@vger.kernel.org, john.stultz@linaro.org, dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org List-Id: devicetree@vger.kernel.org On 9/13/2016 12:42 PM, Archit Taneja wrote: > > > On 9/12/2016 6:49 PM, Rob Herring wrote: >> On Thu, Sep 01, 2016 at 07:06:52PM +0530, Archit Taneja wrote: >>> Make the following changes in the HDMI gpio bindings: >>> >>> - Use "-gpios" as the suffix for all the gpio names >>> - Move all the gpios to optional, since there are platforms that use >>> none >>> of them. >>> - The HPD gpio is a standard one, remove the "qcom,hdmi-tx-" prefix from >>> it. >>> - Add a missing lpm gpio used on some platforms. >>> >>> Make the necessary changes in the driver to incorporate these changes. >>> >>> There hasn't been any upstream DT that uses the HDMI bindings, so it's >>> okay to change and move around these properties. >>> >>> Cc: Rob Herring >>> Cc: devicetree@vger.kernel.org >>> Signed-off-by: Archit Taneja >>> --- >>> v2: >>> - Keep "qcom,hdmi-tx-" suffix for all gpios except for hpd. >>> - Use "-gpios" suffix instead of "-gpio". >>> - Move all the gpios to optional properties. >>> >>> .../devicetree/bindings/display/msm/hdmi.txt | 11 ++++++----- >>> drivers/gpu/drm/msm/hdmi/hdmi.c | 21 >>> +++++++++++++++++++-- >>> 2 files changed, 25 insertions(+), 7 deletions(-) >>> >>> diff --git a/Documentation/devicetree/bindings/display/msm/hdmi.txt >>> b/Documentation/devicetree/bindings/display/msm/hdmi.txt >>> index ce84459..f1a83ab 100644 >>> --- a/Documentation/devicetree/bindings/display/msm/hdmi.txt >>> +++ b/Documentation/devicetree/bindings/display/msm/hdmi.txt >>> @@ -13,17 +13,18 @@ Required properties: >>> - interrupts: The interrupt signal from the hdmi block. >>> - clocks: device clocks >>> See ../clocks/clock-bindings.txt for details. >>> -- qcom,hdmi-tx-ddc-clk-gpio: ddc clk pin >>> -- qcom,hdmi-tx-ddc-data-gpio: ddc data pin >>> -- qcom,hdmi-tx-hpd-gpio: hpd pin >>> - core-vdda-supply: phandle to supply regulator >>> - hdmi-mux-supply: phandle to mux regulator >>> - phys: the phandle for the HDMI PHY device >>> - phy-names: the name of the corresponding PHY device >>> >>> Optional properties: >>> -- qcom,hdmi-tx-mux-en-gpio: hdmi mux enable pin >>> -- qcom,hdmi-tx-mux-sel-gpio: hdmi mux select pin >>> +- qcom,hdmi-tx-ddc-clk-gpios: ddc clk pin >>> +- qcom,hdmi-tx-ddc-data-gpios: ddc data pin >> >> Sorry, for raising another point, but couldn't you use the i2c-gpio >> binding for these instead? > > I'm not entirely sure what these are used for either, they predate the > APQ8064 SoC. They are certainly not bit-banged to implement i2c, since > the driver just sets them to a high during driver initialization, and > we have our dedicated i2c controller anyway. > I just checked some old qualcomm kernels. It looks like they were passed as gpios just so that the pins could be configured(function, pull up/down, strength etc) using gpiolib api. I guess these kernels predated pinctrl drivers. I will post a new revision of the patch with these removed. Thanks, Archit > Rob, > > Are you aware why we have these for older SoCs? > > Thanks, > Archit > >> >>> +- hpd-gpios: hpd pin >>> +- qcom,hdmi-tx-mux-en-gpios: hdmi mux enable pin >>> +- qcom,hdmi-tx-mux-sel-gpios: hdmi mux select pin >>> +- qcom,hdmi-tx-mux-lpm-gpios: hdmi mux lpm pin >>> - power-domains: reference to the power domain(s), if available. >>> - pinctrl-names: the pin control state names; should contain "default" >>> - pinctrl-0: the default pinctrl state (active) > -- Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project