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From: Marcel Ziswiler <marcel.ziswiler@toradex.com>
To: "linux-arm-kernel@lists.infradead.org" 
	<linux-arm-kernel@lists.infradead.org>,
	"vladimir_zapolskiy@mentor.com" <vladimir_zapolskiy@mentor.com>
Cc: "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
	"robh+dt@kernel.org" <robh+dt@kernel.org>,
	"pawel.moll@arm.com" <pawel.moll@arm.com>,
	"stefan@agner.ch" <stefan@agner.ch>,
	"devicetree@vger.kernel.org" <devicetree@vger.kernel.org>,
	"festevam@gmail.com" <festevam@gmail.com>,
	"mark.rutland@arm.com" <mark.rutland@arm.com>,
	"galak@codeaurora.org" <galak@codeaurora.org>,
	"ijc+devicetree@hellion.org.uk" <ijc+devicetree@hellion.org.uk>,
	"stillcompiling@gmail.com" <stillcompiling@gmail.com>,
	"ynezz@true.cz" <ynezz@true.cz>,
	"shawnguo@kernel.org" <shawnguo@kernel.org>,
	"l.stach@pengutronix.de" <l.stach@pengutronix.de>,
	"kernel@pengutronix.de" <kernel@pengutronix.de>,
	"linux@arm.linux.org.uk" <linux@arm.linux.org.uk>
Subject: Re: [PATCH v5 1/2] ARM: dts: imx6: Add support for Toradex Apalis iMX6Q/D SoM
Date: Fri, 16 Sep 2016 13:28:42 +0000	[thread overview]
Message-ID: <1474032521.3103.17.camel@toradex.com> (raw)
In-Reply-To: <97a3d506-35a0-2a15-18ef-2719c0596cc1@mentor.com>

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@true.cz>
> > 
> > Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
> > Signed-off-by: Petr Štetiar <ynezz@true.cz>
> > Reviewed-by: Stefan Agner <stefan@agner.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 because the change is in mainline now below is kind of out of date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

  parent reply	other threads:[~2016-09-16 21:03 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-02-05 16:12 [PATCH v5 0/2] ARM: dts: imx6: Add support for Toradex Apalis iMX6Q/D SoM/Ixora carrier board Marcel Ziswiler
2016-02-05 16:12 ` [PATCH v5 1/2] ARM: dts: imx6: Add support for Toradex Apalis iMX6Q/D SoM Marcel Ziswiler
2016-08-29 13:28   ` Vladimir Zapolskiy
2016-08-29 20:54     ` Stefan Agner
2016-09-16 13:28     ` Marcel Ziswiler [this message]
2016-02-05 16:12 ` [PATCH v5 2/2] ARM: dts: imx6: Add support for Toradex Ixora carrier board Marcel Ziswiler
2016-02-14  6:54 ` [PATCH v5 0/2] ARM: dts: imx6: Add support for Toradex Apalis iMX6Q/D SoM/Ixora " Shawn Guo

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