topic Re: how do rotate hid-multitouch in i.MX Processors

how do rotate hid-multitouch

MicMoba — Fri, 04 Sep 2020 10:40:27 GMT

Hi I have a touchscreen connected over USB to my i.MX6 quad.

The touch controller is detected by my Linux:

[ 2.299132] hid-multitouch 0003:0EEF:C002.0001: input,hiddev96: USB HID v1.11 Mouse [eGalax Inc. eGalaxTouch P80H32 4009 v0059_M00 k03_215] on usb-ci_hdrc.0-1/input0

And the touch works, but I have to rotate it by 180°.

Is there a possibility to rotate it over the devicetree?

There is a touchscreen-inverted-x property in the common touchscreen description but I don't know how to use it in the DT.

Thanks

Re: how do rotate hid-multitouch

MicMoba — Fri, 04 Sep 2020 10:44:08 GMT

Sorry I forgot. I use a framebuffer system.

Re: how do rotate hid-multitouch

igorpadykov — Sat, 05 Sep 2020 00:32:22 GMT

Hi MicMoba

for better understanding of these properties one can look at

"DT helper functions for touchscreen devices "

https://source.codeaurora.org/external/imx/linux-imx/tree/drivers/input/touchscreen/of_touchscreen.c?h=imx_5.4.24_2.1.0

Best regards
igor

Re: how do rotate hid-multitouch

MicMoba — Sat, 05 Sep 2020 13:39:30 GMT

Hi Igor,

thanks for reply. I always read the DT Documetation about touchscreen but I don't know how to implement this in my DT. When I use a I2C touchscreen I put the touchscreen properties into the I2C node. But I don't know where to place the properties when I have a USB touchscreen.

Re: how do rotate hid-multitouch

ujwal-setlur — Fri, 25 Sep 2020 01:20:56 GMT

I have exactly the same problem. Did you figure it out?

Re: how do rotate hid-multitouch

MicMoba — Fri, 25 Sep 2020 04:09:09 GMT

Hi ujwal-setlur

no not really. I wanted to rotate the touch with the device tree but I didn't find a way to do that.

Finally I used the tool ts_calibrate which comes with libts. After calibrating the touch was rotated.

You can test it with ts_test which comes also with libts.

But if I started my QT application and the touch wasn't rotated as I expected. So I use the following QT environment variable to rotate the touch in QT:

export QT_QPA_EVDEV_TOUCHSCREEN_PARAMETERS=/dev/input/event0:rotate=180

Re: how do rotate hid-multitouch

ujwal-setlur — Fri, 25 Sep 2020 04:38:09 GMT

Thanks @MicMoba . I am on Android-9, so I wonder if that will work for me, but I will give it a shot!