Input: add support for generic GPIO-based matrix keypad
authorEric Miao <eric.y.miao@gmail.com>
Mon, 29 Jun 2009 07:20:52 +0000 (00:20 -0700)
committerDmitry Torokhov <dmitry.torokhov@gmail.com>
Mon, 29 Jun 2009 07:30:16 +0000 (00:30 -0700)
commitbab7614d6d1b1fc96ec6c5a7ca34c8641060e659
treef7b493a73b03d39e982a325117a14a04b712d1c0
parentcb589529f74d69abc111887b45308f333f950ade
Input: add support for generic GPIO-based matrix keypad

Original patch by Marek Vasut, modified by Eric in:

1. use delayed work to simplify the debouncing
2. combine col_polarity/row_polarity into a single active_low field
3. use a generic bit array based XOR algorithm to detect key
   press/release, which should make the column assertion time
   shorter and code a bit cleaner
4. remove the ALT_FN handling, which is no way generic, the ALT_FN
   key should be treated as no different from other keys, and
   translation will be done by user space by commands like 'loadkeys'.
5. explicitly disable row IRQs and flush potential pending work,
   and schedule an immediate scan after resuming as suggested
   by Uli Luckas
6. incorporate review comments from many others

Patch tested on Littleton/PXA310 (though PXA310 has a dedicate keypad
controller, I have to configure those pins as generic GPIO to use this
driver, works quite well, though), and Sharp Zaurus model SL-C7x0
and SL-C1000.

[dtor@mail.ru: fix error unwinding path, support changing keymap
 from userspace]
Signed-off-by: Marek Vasut <marek.vasut@gmail.com>
Reviewed-by: Trilok Soni <soni.trilok@gmail.com>
Reviewed-by: Uli Luckas <u.luckas@road.de>
Reviewed-by: Russell King <linux@arm.linux.org.uk>
Reviewed-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Eric Miao <eric.miao@marvell.com>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>
drivers/input/keyboard/Kconfig
drivers/input/keyboard/Makefile
drivers/input/keyboard/matrix_keypad.c [new file with mode: 0644]
include/linux/input/matrix_keypad.h [new file with mode: 0644]