question about sys/bus/i2c/device

I’m a beginner of beagleboard.

         From below website, I find some informationabout read edid
from user space(see below), and it’s very useful to me.
http://groups.google.com/group/beagleboard/browse_thread/thread/ff79a14907cc8805?utoken=wO7b9C4AAADt1MNSQyAzza8h7Om2E8em3PCAJN4DukfuDlwfCKb08JMqM2WLZfSAgwj-9F_3BtI

************quote************
Not really usefull for debugging, but recent kernel list all i2c
devices in /sys:
root@beagleboard:/sys/bus/i2c/devices# ls .
1-0048 1-004a 3-0050 3-0052 3-0054 3-0056
1-0049 1-004b 3-0051 3-0053 3-0055 3-0057
root@beagleboard:/sys/bus/i2c/devices# cat 3-0050/eeprom
...).x��.�XL.&.PT/
��@..a@aYE@EY1@1YH?
@0b�2@@�..2..�2UP.
      �AU5131
�
...).x��.�XL.&.PT/
��@..a@aYE@EY1@1YH?
@0b�2@@�..2..�2UP.
      �AU5131
�
            Q
root@beagleboard:/sys/bus/i2c/devices#
My monitor is an IIyama AU5131, so EDID readout works :slight_smile:

***********end quote*********

         I’d like to try the same way to get edid on my beagleboard. I
have connected a DVI monitor to beagleboard, but in my /sys/bus/i2c/
devices, there is nothing about i2c 3, only some folders for i2c 1.

I see almost the same thing as you, but I also have something on i2c
bus 2:
root@beagleboard:/sys/bus/i2c/devices# ls
1-0048 1-0049 1-004a 1-004b 2-0068

i2cdetect gives me:
root@beagleboard:/# i2cdetect -a -y -r 3
     0 1 2 3 4 5 6 7 8 9 a b c d e f
00: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
10: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
20: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
30: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
40: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
50: 50 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
60: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
70: -- -- -- -- -- -- -- -- -- -- -- -- -- -- -- --
root@beagleboard:/#

I have noticed the following when I boot the beagleboard.
Starting i2c...
FATAL: Module i2c_pxa not found.
FATAL: Module i2c_dev not found.

-do you see the same thing?

Quist

i have test i2c bus 1,2,3 with ioctl, all of they work well
it's strange that you have a device on bus 2...since bus2 is NC on
beagleboard, it works defaultly as GPIO.

i havn't seem any message about i2c failed.