linux-kernel - Re: [PATCH v5 1/2] ARM: dts: imx6: Add support for Toradex Apalis iMX6Q/D SoM

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <1474032521.3103.17.camel@toradex.com>
Date:   Fri, 16 Sep 2016 13:28:42 +0000
From:   Marcel Ziswiler <marcel.ziswiler@...adex.com>
To:     "linux-arm-kernel@...ts.infradead.org" 
        <linux-arm-kernel@...ts.infradead.org>,
        "vladimir_zapolskiy@...tor.com" <vladimir_zapolskiy@...tor.com>
CC:     "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
        "robh+dt@...nel.org" <robh+dt@...nel.org>,
        "pawel.moll@....com" <pawel.moll@....com>,
        "stefan@...er.ch" <stefan@...er.ch>,
        "devicetree@...r.kernel.org" <devicetree@...r.kernel.org>,
        "festevam@...il.com" <festevam@...il.com>,
        "mark.rutland@....com" <mark.rutland@....com>,
        "galak@...eaurora.org" <galak@...eaurora.org>,
        "ijc+devicetree@...lion.org.uk" <ijc+devicetree@...lion.org.uk>,
        "stillcompiling@...il.com" <stillcompiling@...il.com>,
        "ynezz@...e.cz" <ynezz@...e.cz>,
        "shawnguo@...nel.org" <shawnguo@...nel.org>,
        "l.stach@...gutronix.de" <l.stach@...gutronix.de>,
        "kernel@...gutronix.de" <kernel@...gutronix.de>,
        "linux@....linux.org.uk" <linux@....linux.org.uk>
Subject: Re: [PATCH v5 1/2] ARM: dts: imx6: Add support for Toradex Apalis
 iMX6Q/D SoM

Hi Vladimir

On Mon, 2016-08-29 at 16:28 +0300, Vladimir Zapolskiy wrote:
> Hi Marcel,
> 
> On 02/05/2016 06:12 PM, Marcel Ziswiler wrote:
> > 
> > From: Petr Štetiar <ynezz@...e.cz>
> > 
> > Signed-off-by: Marcel Ziswiler <marcel.ziswiler@...adex.com>
> > Signed-off-by: Petr Štetiar <ynezz@...e.cz>
> > Reviewed-by: Stefan Agner <stefan@...er.ch>
> > ---
> > 
> because the change is in mainline now below is kind of out of date
> information, but you may find it helpful.
> 
> [snip]
> 
> > 
> > - fixed HDMI DDC (requires GPIO-based bitbanging I2C to be enabled)
> This is not needed.
> 
> [snip]
> 
> > 
> > +	/* DDC_I2C: I2C2_SDA/SCL on MXM3 205/207 */
> > +	i2cddc: i2c@0 {
> > +		compatible = "i2c-gpio";
> > +		pinctrl-names = "default";
> > +		pinctrl-0 = <&pinctrl_i2c_ddc>;
> > +		gpios = <&gpio3 16 GPIO_ACTIVE_HIGH /* sda */
> > +			 &gpio2 30 GPIO_ACTIVE_HIGH /* scl */
> > +			>;
> > +		i2c-gpio,delay-us = <2>;	/* ~100 kHz */
> > +		status = "disabled";
> > +	};
> > +
> This is not needed.
> 
> [snip]
> 
> > 
> > +	pinctrl_i2c_ddc: gpioi2cddcgrp {
> > +		fsl,pins = <
> > +			/* DDC bitbang */
> > +			MX6QDL_PAD_EIM_EB2__GPIO2_IO30 0x1b0b0
> > +			MX6QDL_PAD_EIM_D16__GPIO3_IO16 0x1b0b0
> > +		>;
> > +	};
> > +
> Practically you don't need this overcomplicated GPIO-based bitbanging
> to emulate I2C, because the DW HDMI controller has a reduced I2C
> controller on board, you may take a look at its support published
> here:
> 
>     http://www.spinics.net/lists/dri-devel/msg116308.html
> 
> To utilize it the pads should be set to HDMI function instead of
> I2C or GPIO.

Works nicely indeed, thanks for letting us know.

> --
> With best wishes,
> Vladimir

Best wishes to you too!

Cheers

Marcel