Weird behavior

Hello,

I have a beagleboard rev c4.
I have a touchscreen controller that I connect to the expansion pins.
The thing is :

When I boot up my board from an external power, the touchscreen is not
detected but When after booting from an external power I press the
reset button, now my touchscreen is detected and work fine :

here the log :

When after booting from an external power :

[ 11.754638] ads7846 spi3.0: touchscreen, irq 293
[ 11.759521] ads7846 spi3.0: no device detected, test read result
was 0x00000000

after reset button :
[ 10.951934] ads7846 spi3.0: touchscreen, irq 293
[ 10.957275] input: ADS7846 Touchscreen as /devices/platform/
omap2_mcspi.3/spi3.0/input/input1

I found that the pin mmc2_dat3 is up since the begining when booting
from external power and when I press the reset button, this pin change
to low state and change again to up state after approximatively 11.5
second.

So I think the controller needs a rising edge in order to work.

How can I make this rising edge on the mmc2_dat3 even if it is booting
up with external power ?

thank you !

up

I wrote this email to let you know that I have successful make this
touch screen to work with Rowboat GingerBread 2.3.4. However, I still
haven't found solution for you problems.
Hope this information is useful for you.