ads7846: data read from tsc2046 are all zeros

Hi all,

I'm working on the tsc2046 touchscreen controller (using ads7846 driver) on
sdp2430 v5.0.1 board. I can't get the touchscreen work with the linux-omap git tree. The driver builds, boots and register itself with no problem, interrupts can also be triggered when touching the panel, but no input events can be read. By enabling debug output, I finally found that all the values read from tsc2046 are all zeros.

Does anyone encounter the same problem? What could be the root cause for this problem? Any suggestions are welcome.

On 11/8/07, *Yang, Xiaopeng* <[email protected] <mailto:[email protected]>> wrote:

Hi all,

I'm working on the tsc2046 touchscreen controller (using ads7846 driver) on
sdp2430 v5.0.1 board. I can't get the touchscreen work with the linux-omap
git tree. The driver builds, boots and register itself with no problem, interrupts can also be triggered when touching the panel, but no input events can be read. By enabling debug output, I finally found that all the
values read from tsc2046 are all zeros.

Does anyone encounter the same problem? What could be the root cause for
this problem? Any suggestions are welcome.

I'd check the pin muxes on the input (SPI I'm guessing) device you are using to connecto to tsc2046). If still nothing I'd hook up logic analyzer to the SPI lines and see what's happening.

- Juha

Signature · 1 line

Madness takes it's toll. Please have exact change.

Hi all,

I captured the signals of the host-side pins of tsc2046, the SPI pins and PENIRQ work correctly except DOUT remains LOW during CS is active. That's why all read values are zore.

It seems like the tsc2046 doesn't work at all. I measured the voltage of the power supply of tsc2046, the Vcc is only 0.93V. This shouldn't happen in the normal operation. Maybe there is a switch to turn the power on for tsc2046?

Thanks,
Xiaopeng

Quoted 21 lines · Juha Kuikka

On 11/8/07, *Yang, Xiaopeng* <[email protected] <mailto:[email protected]>> wrote:

Hi all,

I'm working on the tsc2046 touchscreen controller (using ads7846 driver) on
sdp2430 v5.0.1 board. I can't get the touchscreen work with the linux-omap
git tree. The driver builds, boots and register itself with no
problem,
interrupts can also be triggered when touching the panel, but no
input
events can be read. By enabling debug output, I finally found that all the
values read from tsc2046 are all zeros.

Does anyone encounter the same problem? What could be the root cause for
this problem? Any suggestions are welcome.

Quoted 7 lines

I'd check the pin muxes on the input (SPI I'm guessing) device you are using to connecto to tsc2046). If still nothing I'd hook up logic analyzer to the SPI lines and see what's happening.

- Juha

Signature · 1 line

Madness takes it's toll. Please have exact change.

_______________________________________________
Linux-omap-open-source mailing list
[email protected]
http://linux.omap.com/mailman/listinfo/linux-omap-open-source