About problem of Rock960 board's I2C being not able to driven up


#1

Recently our R&D team is evaluating Rock960 board. We encountered some problem of Camera integration. Currently our R&D progress is blocked at I2C being not able to driven up。 Even we are using official open-source code project and Devicetree file: rock960-model-ab-linux.dtb. The phenomenon is any enabled I2C bus, SDA SCLkeep low. If externally connect to pull-up circuit,SDA become high voltage,but SCL is still less than 0.2V.

Check dmesg, it reports: “rk3x-i2c ff120000.i2c: timeout, ipd: 0x00, state:1”

The code we downloaded is as below
repo init -u https://github.com/96rocks/manifests -m rock960.xml

Devicetree files:

rock960-model-ab-linux.dts


#2

which hardware port are you using? i2c is available on both HS and LS connector.


#3

Thank you for the reply. We are using i2c2 and i2c7. And I found only i2c0 which connects to PMIC is working.


#4

on the rock960-model-ab-debian-lxde-armhf-20180814_2020.img firmware, we hooked up a eeprom, r/w is working fine.

root@linaro-alip:~# i2cdetect -r 7
WARNING! This program can confuse your I2C bus, cause data loss and worse!
I will probe file /dev/i2c-7 using read byte commands.
I will probe address range 0x03-0x77.
Continue? [Y/n] Y
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – -- – -- – -- –
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: – -- – -- – -- – -- – -- – -- – -- – --
50: 50 51 52 53 54 55 56 57 – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: – -- – -- – -- – --
root@linaro-alip:~# i2cset -y 7 0x50 0x02 0x20
root@linaro-alip:~# i2cget -y 7 0x51 0x02
0x20


#5

Dear HipBoi,

Thank you for your reply and the test you did. It is really good news! I noticed the rock960-model-ab-debian-lxde-armhf-20180814_2020.img has been newly released.

But may I ask what code and device tree file is it based on? I am not sure where to find the source code to compare what is wrong with my previous load code.

Best Regards,
Sonia


#6

You can refer the device tree here:

https://github.com/96rocks/kernel/blob/rock960-4.4-dev/arch/arm64/boot/dts/rockchip/rock960-model-ab-linux.dts


#7

Still, I’m experiencing timeout issue on I2C7. Is it due to the absence of external Pull-up?

-Mani