From mboxrd@z Thu Jan 1 00:00:00 1970 From: Philipp Zabel Subject: Re: [PATCH 1/3] staging: imx-drm: document internal HDMI I2C master controller DT binding Date: Mon, 01 Dec 2014 16:11:43 +0100 Message-ID: <1417446703.4624.18.camel@pengutronix.de> References: <1416073759-19939-1-git-send-email-vladimir_zapolskiy@mentor.com> <1416073759-19939-2-git-send-email-vladimir_zapolskiy@mentor.com> <547C8113.3050100@mentor.com> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <547C8113.3050100@mentor.com> Sender: linux-media-owner@vger.kernel.org To: Vladimir Zapolskiy Cc: Shawn Guo , Wolfram Sang , devicetree@vger.kernel.org, linux-media@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-i2c@vger.kernel.org List-Id: devicetree@vger.kernel.org Am Montag, den 01.12.2014, 16:54 +0200 schrieb Vladimir Zapolskiy: > Hi Philipp and Shawn, > > On 15.11.2014 19:49, Vladimir Zapolskiy wrote: > > Provide information about how to bind internal iMX6Q/DL HDMI DDC I2C > > master controller. The property is set as optional one, because iMX6 > > HDMI DDC bus may be represented by one of general purpose I2C busses > > found on SoC. > > > > Signed-off-by: Vladimir Zapolskiy > > Cc: Wolfram Sang > > Cc: Philipp Zabel > > Cc: Shawn Guo > > Cc: devicetree@vger.kernel.org > > Cc: linux-media@vger.kernel.org > > Cc: linux-arm-kernel@lists.infradead.org > > Cc: linux-i2c@vger.kernel.org > > --- > > Documentation/devicetree/bindings/staging/imx-drm/hdmi.txt | 10 +++++++++- > > 1 file changed, 9 insertions(+), 1 deletion(-) > > > > diff --git a/Documentation/devicetree/bindings/staging/imx-drm/hdmi.txt b/Documentation/devicetree/bindings/staging/imx-drm/hdmi.txt > > index 1b756cf..43c8924 100644 > > --- a/Documentation/devicetree/bindings/staging/imx-drm/hdmi.txt > > +++ b/Documentation/devicetree/bindings/staging/imx-drm/hdmi.txt > > @@ -10,6 +10,8 @@ Required properties: > > - #address-cells : should be <1> > > - #size-cells : should be <0> > > - compatible : should be "fsl,imx6q-hdmi" or "fsl,imx6dl-hdmi". > > + If internal HDMI DDC I2C master controller is supposed to be used, > > + then "simple-bus" should be added to compatible value. > > - gpr : should be <&gpr>. > > The phandle points to the iomuxc-gpr region containing the HDMI > > multiplexer control register. > > @@ -22,6 +24,7 @@ Required properties: > > > > Optional properties: > > - ddc-i2c-bus: phandle of an I2C controller used for DDC EDID probing > > + - ddc: internal HDMI DDC I2C master controller > > > > example: > > > > @@ -32,7 +35,7 @@ example: > > hdmi: hdmi@0120000 { > > #address-cells = <1>; > > #size-cells = <0>; > > - compatible = "fsl,imx6q-hdmi"; > > + compatible = "fsl,imx6q-hdmi", "simple-bus"; > > reg = <0x00120000 0x9000>; > > interrupts = <0 115 0x04>; > > gpr = <&gpr>; > > @@ -40,6 +43,11 @@ example: > > clock-names = "iahb", "isfr"; > > ddc-i2c-bus = <&i2c2>; > > > > + hdmi_ddc: ddc { > > + compatible = "fsl,imx6q-hdmi-ddc"; > > + status = "disabled"; > > + }; > > + > > port@0 { > > reg = <0>; > > > > > > knowing in advance that I2C framework lacks a graceful support of non > fully compliant I2C devices, do you have any objections to the proposed > iMX HDMI DTS change? I'm not sure about this. Have you seen "drm: Decouple EDID parsing from I2C adapter"? I feel like in the absence of a ddc-i2c-bus property the imx-hdmi/dw-hdmi driver should try to use the internal HDMI DDC I2C master controller, bypassing the I2C framework altogether. regards Philipp