summoningdark wrote:
I'm having trouble getting the samsung touchscreen working with an overo fire and a palo43. I have the LCD working as the main display, but the touchscreen doesn't appear to do anything. the ts_print_raw command never reports anything, and the ts_calibrate program doesn't register anything either. I checked the resistances on the LCD and they are within spec. Are there any other ways to check the LCD?
On thing that worries me a little is that both the LCD and the overo module get pretty hot in operation.
further investigation revealed some interesting things. The touchscreen controller chip is detected by the kernel during boot:
ads7846 spi1.0: touchscreen, irq 274
input: ADS784x Touchscreen as /devices/platform/omap2_mcspi.1/spi1.0/input/input0
but probing the x+-,y+- connections to the touchscreen reveals that the chip is not doing anything. according to the datasheet, the chip should drive +3.3v on each of the + touchscreen lines at some point during a measurement, but no voltage is seen after boot. Also after the initial serial transiaction during boot, there is no more communication on the spi bus. From my reading of the datasheet, each conversion of the A/D in the ads7846 is started by a byte written to the device, so I would expect a constant polling of the chip to read touchscreen data. the only other way I could see it working is to use the pen interrupt, but the control byte written to the chip at boot is 0xD3 which disables the pen interrupt by setting PD1 and PD0 to 1.
Does anyone know what's going on with the driver, or how this is supposed to work?
