From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Date: Fri, 20 Jul 2018 12:05:30 -0600 From: Rob Herring Subject: Re: [PATCH 1/5] cec-gpio.txt: add v5-gpios for testing the 5V line Message-ID: <20180720180530.GA21569@rob-hp-laptop> References: <20180717132909.92158-1-hverkuil@xs4all.nl> <20180717132909.92158-2-hverkuil@xs4all.nl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180717132909.92158-2-hverkuil@xs4all.nl> To: Hans Verkuil Cc: linux-media@vger.kernel.org, devicetree@vger.kernel.org, Hans Verkuil List-ID: On Tue, Jul 17, 2018 at 03:29:05PM +0200, Hans Verkuil wrote: > From: Hans Verkuil > > In order to debug the HDMI 5V line we need to add a new v5-gpios > property. > > Signed-off-by: Hans Verkuil > --- > .../devicetree/bindings/media/cec-gpio.txt | 17 ++++++++++------- > 1 file changed, 10 insertions(+), 7 deletions(-) > > diff --git a/Documentation/devicetree/bindings/media/cec-gpio.txt b/Documentation/devicetree/bindings/media/cec-gpio.txt > index 12fcd55ed153..1d53ce89da74 100644 > --- a/Documentation/devicetree/bindings/media/cec-gpio.txt > +++ b/Documentation/devicetree/bindings/media/cec-gpio.txt > @@ -4,8 +4,8 @@ The HDMI CEC GPIO module supports CEC implementations where the CEC line > is hooked up to a pull-up GPIO line and - optionally - the HPD line is > hooked up to another GPIO line. > > -Please note: the maximum voltage for the CEC line is 3.63V, for the HPD > -line it is 5.3V. So you may need some sort of level conversion circuitry > +Please note: the maximum voltage for the CEC line is 3.63V, for the HPD and > +5V lines it is 5.3V. So you may need some sort of level conversion circuitry > when connecting them to a GPIO line. > > Required properties: > @@ -22,15 +22,18 @@ If the CEC line is not associated with an HDMI receiver/transmitter, then > the following property is optional: > > - hpd-gpios: gpio that the HPD line is connected to. > + - v5-gpios: gpio that the 5V line is connected to. This is a bit strange without the context of debugging. So can you mention that here. With that, Reviewed-by: Rob Herring > > Example for the Raspberry Pi 3 where the CEC line is connected to > -pin 26 aka BCM7 aka CE1 on the GPIO pin header and the HPD line is > -connected to pin 11 aka BCM17 (some level shifter is needed for this!): > +pin 26 aka BCM7 aka CE1 on the GPIO pin header, the HPD line is > +connected to pin 11 aka BCM17 and the 5V line is connected to pin > +15 aka BCM22 (some level shifter is needed for the HPD and 5V lines!): > > #include > > cec-gpio { > - compatible = "cec-gpio"; > - cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>; > - hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>; > + compatible = "cec-gpio"; > + cec-gpios = <&gpio 7 (GPIO_ACTIVE_HIGH|GPIO_OPEN_DRAIN)>; > + hpd-gpios = <&gpio 17 GPIO_ACTIVE_HIGH>; > + v5-gpios = <&gpio 22 GPIO_ACTIVE_HIGH>; > }; > -- > 2.18.0 >