I have i.MX53 QSB with Seiko WVGA Rev-B display connected to Expansion Port. On board is written SCH-27104 Rev B, 700-27104 Rev C and I use preinstalled Ubuntu 10.04.
Under X, touchscreen works fine, it only needs calibration, but I don't need this.
I have compiled Qt embedded 4.8.4 with tslib mouse driver. Without X, ts_calibrate works fine and touchscreen in my Qt embedded application moves fine, but when i tap, it only sends pressed() signal, not clicked() - many standard things like closing windows with cross button, system dialogs etc. does not work - buttons looks like pressed (changes colour, border etc.) but does'n execute desired action. My buttons using pressed() signals works fine.
My problem looks similar to How to make Seiko-LCD detect "tap" (and interpret it as a click)? , but my touchscreen works fine under X, problem is only with Qt embedded - without X.