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Date:      Mon, 26 Apr 2021 16:11:38 +0200
From:      Emmanuel Vadot <manu@bidouilliste.com>
To:        Mark Murray <markm@FreeBSD.org>
Cc:        freebsd-arm <freebsd-arm@freebsd.org>
Subject:   Re: I2C/IIC working on RPI4 8GB?
Message-ID:  <20210426161138.a8f44b6e1134f73a411be57d@bidouilliste.com>
In-Reply-To: <1C2DD11C-B1F6-4C2A-9AB0-5F1553520FF5@FreeBSD.org>
References:  <1C2DD11C-B1F6-4C2A-9AB0-5F1553520FF5@FreeBSD.org>

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On Sun, 25 Apr 2021 13:32:00 +0100
Mark Murray <markm@FreeBSD.org> wrote:

> Hi All,
> 
> Does anyone here have IIC/I2C working on a CURRENT (I'm running latest) FreeBSD?
> 
> I've never seen it work; Last time I had working IIC was on an RPI3.
> 
> There is a /dev/iic0, and I have a known working RTC on it, but the scan just times out:
> 
> [root@grasshopper ~]# i2c -s
> Hardware may not support START/STOP scanning; trying less-reliable read method.
> <TIMEOUT>
> Scanning I2C devices on /dev/iic0: <none found>
> 
> 
> I suspect something not-quite-right in DTS land, but I lack the knowledge to investigate. I've done some random stumbling around in the dark with overlays and the like, but I've either seen the above error, or a total lack of /dev/iic0.
> 
> Thanks!
> 
> M
> --
> Mark R V Murray
> 

 I2C is disabled by default.
 You need to copy i2c0.dtbo (or i2c1<X> I don't know which one maps to
the pins you want to use) in the ESP partition and add "i2c<X>" to the
dtoverlay line in config.txt

-- 
Emmanuel Vadot <manu@bidouilliste.com> <manu@FreeBSD.org>



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