From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:39128 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755110AbeBOIfy (ORCPT ); Thu, 15 Feb 2018 03:35:54 -0500 Subject: Patch "media: dt-bindings/media/cec-gpio.txt: mention the CEC/HPD max voltages" has been added to the 4.15-stable tree To: hverkuil@xs4all.nl, gregkh@linuxfoundation.org, hans.verkuil@cisco.com, mchehab@s-opensource.com, robh@kernel.org Cc: , From: Date: Thu, 15 Feb 2018 09:34:36 +0100 Message-ID: <1518683676195187@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled media: dt-bindings/media/cec-gpio.txt: mention the CEC/HPD max voltages to the 4.15-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: media-dt-bindings-media-cec-gpio.txt-mention-the-cec-hpd-max-voltages.patch and it can be found in the queue-4.15 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From dac15ed62dc9d7898d3695a3c393d6f712d66185 Mon Sep 17 00:00:00 2001 From: Hans Verkuil Date: Sat, 16 Dec 2017 05:44:13 -0500 Subject: media: dt-bindings/media/cec-gpio.txt: mention the CEC/HPD max voltages From: Hans Verkuil commit dac15ed62dc9d7898d3695a3c393d6f712d66185 upstream. Mention the maximum voltages of the CEC and HPD lines. Since in the example these lines are connected to a Raspberry Pi and the Rpi GPIO lines are 3.3V it is a good idea to warn against directly connecting the HPD to the Raspberry Pi's GPIO line. Signed-off-by: Hans Verkuil Reviewed-by: Rob Herring Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Greg Kroah-Hartman --- Documentation/devicetree/bindings/media/cec-gpio.txt | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) --- a/Documentation/devicetree/bindings/media/cec-gpio.txt +++ b/Documentation/devicetree/bindings/media/cec-gpio.txt @@ -4,6 +4,10 @@ The HDMI CEC GPIO module supports CEC im 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 +when connecting them to a GPIO line. + Required properties: - compatible: value must be "cec-gpio". - cec-gpios: gpio that the CEC line is connected to. The line should be @@ -21,7 +25,7 @@ the following property is optional: 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: +connected to pin 11 aka BCM17 (some level shifter is needed for this!): #include Patches currently in stable-queue which might be from hverkuil@xs4all.nl are queue-4.15/media-dt-bindings-media-cec-gpio.txt-mention-the-cec-hpd-max-voltages.patch