From mboxrd@z Thu Jan  1 00:00:00 1970
From: sebastian.hesselbarth@gmail.com (Sebastian Hesselbarth)
Date: Sat, 22 Feb 2014 23:25:41 +0100
Subject: Stuck getting DTS working for a new kirkwood board
In-Reply-To: <5308FE07.5070809@sigpipe.me>
References: <20140221013407.GX7862@titan.lakedaemon.net>
 <5307029C.20006@sigpipe.me> <20140221151530.GZ7862@titan.lakedaemon.net>
 <5307A727.9080508@sigpipe.me> <20140221200855.GM7862@titan.lakedaemon.net>
 <5307CCCD.5010505@sigpipe.me> <20140221221251.GH11878@lunn.ch>
 <530865C9.6000704@sigpipe.me> <20140222184119.GF6667@lunn.ch>
 <5308F16C.1070207@sigpipe.me> <20140222193031.GG6667@lunn.ch>
 <5308FE07.5070809@sigpipe.me>
Message-ID: <530923E5.7090901@gmail.com>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

On 02/22/2014 08:44 PM, Dashie wrote:
> On 02/22/2014 08:30 PM, Andrew Lunn wrote:
>>> root at debian:~# i2cdetect 0
>>> WARNING! This program can confuse your I2C bus, cause data loss and worse!
>>> I will probe file /dev/i2c-0.
>>> I will probe address range 0x03-0x77.
>>> Continue? [Y/n]
>>>      0  1  2  3  4  5  6  7  8  9  a  b  c  d  e  f
>>> 00:          -- -- -- -- -- -- -- -- -- UU -- -- --
>>> 10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 40: -- -- -- -- -- -- -- -- -- UU -- -- -- -- -- --
>>> 50: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
>>> 60: -- -- -- -- 64 -- -- -- -- -- -- -- -- -- -- --
>>> 70: -- -- -- -- -- -- -- --
>> The datasheet for M41TC8025 says it uses 0x64.
>>
>> Could you of read the part wrong from the photo?
>>
>>        Andrew
> The only readings on the chip is :
> "M41T80
> ST(logo) E9927"
>
> I have a picture here :
> http://wiki.sigpipe.me/lib/exe/fetch.php?media=hacking:img_3329.jpg
>

Looking at the picture, I can see M41T80 and an Atmel i2c eeprom above
it. Given to M41T80 datasheet its i2c address is fixed at 0x68 as
Gerhard also noted. The eeprom is coded to 0x50 - you can see that all
right pins are connected to GND which is on pin 4, the white arrow
points to pin 1. You should see both devices but none is in the above
i2cdetect output.

Kirkwood only has one i2c controller, so my guess is that the devices
you are looking for are either connected to some i2c switch or mux, are
on a gpio bitbang i2c, or not connected to the SoC but some
microcontroller instead.

 From the wiki link above, you say there is an NXP 8051-compatible uC..
that would be my guess then.

Sebastian