linux/arch/avr32
Ben Nizette 92c548cd35 favr32: improve touchscreen response
The ezLCD+101 board (to which an favr-32 is fitted) has a long,
unshielded, nasty lead between the touch panel and the ads7843 touch
controller.  In order to get satisfactory response then, we need to
employ every noise-reduction trick in the driver's arsenal.  After
extensive fiddling I've found some good settings:

1) We keep vref on all the time to dramatically reduce settling times
(at the cost of a tiny increase in power consumption).

2) Despite 1 the settling time is still non-zero.  500uS is plenty of
time for the signals to settle

3) Despite 1 and 2 there's still a little bit of noise around.  By
setting a pen recheck delay we make the panel feel less touchy and
twitchy.

Someone with more time and patience myself might be able to tune this
numbers further but these settings are now perfectly acceptable for
normal use.

Tested on ezLCD+101 though should only improve response on other ezLCD+/
favr-32 boards too.

Signed-off-by: Ben Nizette <bn@niasdigital.com>
Signed-off-by: Haavard Skinnemoen <haavard.skinnemoen@atmel.com>
2009-07-27 13:16:45 +02:00
..
boards favr32: improve touchscreen response 2009-07-27 13:16:45 +02:00
boot avr32: remove .note.gnu.build-id section when making vmlinux.bin 2008-12-17 11:44:10 +01:00
configs avr32: Add support for Mediama RMTx add-on board for ATNGW100 2009-06-08 12:55:35 +02:00
include/asm sched: INIT_PREEMPT_COUNT 2009-07-10 14:24:05 -07:00
kernel Remove multiple KERN_ prefixes from printk formats 2009-07-08 10:30:03 -07:00
lib avr32/lib: fix unaligned memcpy where len < 4 2009-07-27 12:37:28 +02:00
mach-at32ap avr32: Fix clash in ATMEL_USART_ flags 2009-06-03 11:38:20 +02:00
mm Move FAULT_FLAG_xyz into handle_mm_fault() callers 2009-06-21 13:08:22 -07:00
oprofile Add kernel support for oprofile callgraphs on AVR32 2008-09-22 09:51:01 +02:00
Kconfig Merge branch 'avr32-arch' of git://git.kernel.org/pub/scm/linux/kernel/git/hskinnemoen/avr32-2.6 2009-04-05 11:15:28 -07:00
Kconfig.debug [AVR32] Include instrumentation menu 2008-01-25 08:31:40 +01:00
Makefile avr32: drop unused CLEAN_FILES 2009-05-01 10:54:00 +02:00