From mboxrd@z Thu Jan  1 00:00:00 1970
From: Wolfram Sang <wsa-z923LK4zBo2bacvFa/9K2g@public.gmane.org>
Subject: Re: Problem with multiple i2c multiplexers on the same bus
Date: Fri, 31 Oct 2014 22:59:39 +0100
Message-ID: <20141031215938.GA5370@katana>
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To: Martin Belanger <martin.belanger-Ir6+u9MVKBtBDgjK7y7TUQ@public.gmane.org>
Cc: Guenter Roeck <linux-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org>, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Jean Delvare <jdelvare-l3A5Bk7waGM@public.gmane.org>
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> You are correct Guenter.  We need to address both i2c- and gpio-based
> multiplexers.  You and Jean suggested the following solution:
>=20
> I2C Mux:  i2c-N-mux-i2c-XX (chan_id M)
> GPIO Mux: i2c-N-mux-gpio-XX (chan_id M)
>=20
> Where XX is the i2c address or the first GPIO pin number.  This
> ensures unique IDs for both technologies.

I rediscovered this series:

http://www.spinics.net/lists/linux-i2c/msg11542.html
("i2c-mux: expose i2c bus topology under sysfs")

=46rom a glimpse, I like this approach better. I wonder if we can maintain
backward compatibility somehow. I need to play with it. But not today,
this has to wait till tomorrow.


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