From: Ben Gardiner Date: Thu, 9 Dec 2010 21:51:04 +0000 (-0500) Subject: da850-evm: add UI Expander pushbuttons X-Git-Tag: v2.6.38-rc1~471^2^2~3^2~5 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=75929f5e2bcba7cc328fcf9a3d7ba7076946ac3a;p=pandora-kernel.git da850-evm: add UI Expander pushbuttons This patch adds EV_KEYs for each of the 8 pushbuttons on the UI board via a gpio-key device. The expander is a tca6416; it controls the SEL_{A,B,C} lines which enable and disable the peripherals found on the UI board in addition to the 8 pushbuttons mentioned above. The reason the existing tca6416-keypad driver is not employed is because there was no aparent way to keep the gpio lines used as SEL_{A,B,C} registered while simultaneously registering the pushbuttons as a tca6416-keypad instance. Some experimentation with the polling interval was performed; we were searching for the largest polling interval that did not affect the feel of the responsiveness of the buttons. It is very subjective but 200ms seems to be a good value that accepts firm pushes but rejects very light ones. The key values assigned to the buttons were arbitrarily chosen to be F1-F8. Signed-off-by: Ben Gardiner Reviewed-by: Chris Cordahi CC: Govindarajan, Sriramakrishnan Reviewed-by: Sekhar Nori Signed-off-by: Sekhar Nori CC: Kevin Hilman CC: Gabor Juhos Signed-off-by: Kevin Hilman --- Reading git-diff-tree failed