Usage of i2c_-Tools in Barebox

Sascha Hauer s.hauer at
Tue May 5 08:54:50 PDT 2015

Hi Marcel,

On Tue, May 05, 2015 at 04:56:10PM +0200, Marcel Behlau wrote:
> Hi,
> i'm using a phyFLEX-i.MX6 SBC and want to communicate with an
> external µC over I2C. I only want to read/set 1 register, so i tried
> to use the builtin i2c_read and i2c_write-Commands. The µC is
> connected to i2c-bus 1 of the device, so i tried to probe the hole
> bus with "i2c_bus 1 3 30". The command only answered with
> "i2c_probe: No such device". I tried also the busses 0-3, with the
> same result. I searched in the board.c sourcecode of the phyflex,
> but couldn't find i2c related stuff, so i think, i have to add the
> initalisation for the i2c.
> Do i have to add the i2c-init in the boards/phytec-pfla02/board.c
> -file? Is there some documenation about this stuff?

The phyFLEX board is device tree based. You have to enable the i2c
controller in the dts file (same as you would do in the kernel).
Usually a:

&i2c0 {
	status = "okay";

Should be enough. You probably also have to add the proper pinctrl node.


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