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

From	Marcel Ziswiler <marcel.ziswiler@toradex.com>
Newsgroups	linux.kernel
Subject	Re: [PATCH v5 1/2] ARM: dts: imx6: Add support for Toradex Apalis iMX6Q/D SoM
Date	2016-09-16 23:10 +0200
Message-ID	<si8yt-1HA-21@gated-at.bofh.it> (permalink)
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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 because the change is in mainline now below is kind of out of date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

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Re: [PATCH v5 1/2] ARM: dts: imx6: Add support for Toradex Apalis  iMX6Q/D SoM Marcel Ziswiler <marcel.ziswiler@toradex.com> - 2016-09-16 23:10 +0200

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