AVDD28/VDDIO error while intergrating GT911 touch controller with Verdin iMX8M Mini

Technical Support
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1

URGENT HELP IS NEEDED. THANKS IN ADVANCE !!

Verdin iMX8M Mini Quad 2GB/16GB WL/BT IT V 1.1A
BSP Linux 5.4.0
Custom Carrier Board

Trying to integrate Goodix GT911 based 5.5" touchschreen. Kernel module goodix.ko is built error free. But does not load.

root@verdin-imx8mm-06902306:~# dmesg | grep Goodix

[    4.424995] Goodix-TS 3-005d: 3-005d supply AVDD28 not found, using dummy regulator
[    4.438729] Goodix-TS 3-005d: 3-005d supply VDDIO not found, using dummy regulator
[    4.549376] Goodix-TS 3-005d: i2c test failed attempt 1: -6
[    4.585330] Goodix-TS 3-005d: i2c test failed attempt 2: -6
[    4.613082] Goodix-TS 3-005d: I2C communication failure: -6

Device tree is as given below.

&i2c4 {
     touchscreen@5d {
                compatible = "goodix,gt911";
                reg = <0x5d>;
                pinctrl-names = "default";
                // pinctrl-0 =  pinctrl_i2c>;
                interrupt-parent = <&gpio3>;
                interrupts = <0 0>;
                reset-gpios = <&gpio3 12 1>;
                irq-gpios = <&gpio3 13 1>;
                touchscreen-size-x = <1080>;
                touchscreen-size-y = <1920>;
                // AVDD28-supply = <&reg_2v8_p>;
                // VDDIO-supply = <&reg_1v8_p>;
                status = "okay";
    };
};

If I uncomment the AVDD28-supply and VDDIO-supply, then the board does not boot. It halts with the following error.

ERROR: Did not find a cmdline Flattened Device Tree
FDT and ATAGS support not compiled in - hanging
### ERROR ### Please RESET the board ###

In our custom board, we have connected the touchscreen to i2c4 thru a level translator IC.

Thanks and regards

Partha

2

Hi @spsarathy1 ,

Thanks for writing to Toradex Community.

Can you please confirm if you are using Torizon or Yocto BSP Linux? Also share the changes you have done in device tree and kernel config and below command output

cat /etc/issue
dmesg > log.txt
lsmod

Regarding your query have you already tested from userspace? Are you able to see device on i2c channel? Please check with i2ctransfer and see if touchscreen give any response.
What pins are being used for reset and interrupt? Can you share circuit/schematic for touch controller part?

Best Regards
Ritesh Kumar

3

Hi Ritesh,
This is fixed yesterday. Problem is with the touch screen. The touch screen we have, can alternate between 2 I2C address 0x5D and 0x14 based on reset and poweron condition. That is fixed. Now touch screen is responding.
Thanks & regards
Partha

4

Hi @spsarathy1

Please I have exactly the same issue as yours, can you tel me what did you do exactly to fix it, I know there are two i2c slave device addresses: 0x14 and 0x5D that the device alternates but what modifications you did in device tree exactly ?

Thanks

Youssef