topic Re: tsc2004 touchscreen driver on Jelly Bean(JB) jb4.2.1_1.0.0-alpha in i.MX Processors

tsc2004 touchscreen driver on Jelly Bean(JB) jb4.2.1_1.0.0-alpha

ManoharChinnadu — Tue, 02 Apr 2013 14:04:18 GMT

Hi All,

Here i'm using jb4.2.1_1.0.0-alpha base code to bringup android Jelly bean on imx6 based hardware and i'm using tsc2004 Resistive touch screen driver.

From the kernel, i'm able to bringup the touchscreen driver and able to get the events from the touch screen driver to UI. But X and Y co ordinates are not properly configured.

i'm using tsc2004.idc and /data/system/calibration which is working for ICS and which is not effecting on the JB release.

i try to calibrate using ts_calibrate tool to calibrate and it's not working properly.

In JB, what is the procedure to calibrate JB based device?

Thanks in advance.

Re: tsc2004 touchscreen driver on Jelly Bean(JB) jb4.2.1_1.0.0-alpha

EricNelson — Wed, 03 Apr 2013 00:41:27 GMT

Hi Manohar,

The tsc2004 device needs calibration. I haven't yet worked through the JB details, but on ICS (and Gingerbread and Froyo before that), we've needed to patch the ts_calibrator as shown here:

https://github.com/boundarydevices/android_system_core/commits/gingerbread/ts_calibrator

The key piece is that it looks for 'tsdev' on the kernel command line to identify the touch device.

Then you'll need to call out to the calibrator in your init as shown here:

https://github.com/boundarydevices/android_device_boundary/blob/nit6x-wifi/nitrogen6x/init.rc#L124

Or, if you're running on one of our boards, you might be able to copy this set of coefficients into

/sys/module/tsc2004/parameters/calibration:

-68188

695

271392166

-1150

70727

-9349007

Re: tsc2004 touchscreen driver on Jelly Bean(JB) jb4.2.1_1.0.0-alpha

ManoharChinnadu — Fri, 05 Apr 2013 09:37:32 GMT

Thanks Eric,

The /data/system/calibration file coordinates are not picking up from the sysfs entry fil /sys/module/tsc2004/parameters/calibration( from sysfs entry it's showing 0,0,0,0,0,0 value)

The tsc2004.c driver file is not part of the JB release kernel source and i just integrated the driver file by taking from ICS release kernel by modifying the Makefile and Kconfig files.

how does sysfs entry file pickup the calibration coordinates from the /data/system/calibration file from the Android ICS code.?

Re: tsc2004 touchscreen driver on Jelly Bean(JB) jb4.2.1_1.0.0-alpha

EricNelson — Fri, 05 Apr 2013 13:47:32 GMT

Hi Manohar,

The ts_calibrator program does this.

https://github.com/boundarydevices/android_system_core/blob/nitrogen6x/ts_calibrator/ts_calibrator.c#L73

Note that it takes the multi-line data shown above and converts it into a single line, separated by commas.

Re: tsc2004 touchscreen driver on Jelly Bean(JB) jb4.2.1_1.0.0-alpha

EricNelson — Thu, 04 Jul 2013 17:20:33 GMT

We integrated these patches into our latest JB code base, but found that there's an issue running exec from init.rc.

Some notes are available in this post:

http://boundarydevices.com/android-jellybean-on-i-mx6-with-no-disclaimers/