]> pilppa.com Git - linux-2.6-omap-h63xx.git/commit
gpiolib: pcf857x i2c gpio expander support
authorDavid Brownell <dbrownell@users.sourceforge.net>
Tue, 5 Feb 2008 06:28:24 +0000 (22:28 -0800)
committerLinus Torvalds <torvalds@woody.linux-foundation.org>
Tue, 5 Feb 2008 17:44:13 +0000 (09:44 -0800)
commit15fae37d9f5f21571a9618d8353164b6ddfea6f6
tree13b4fb5479cf3a9522c6673cc6ccae20b6658e55
parent1c44f5f16fee880b294f8068354bfb9dddf1349b
gpiolib: pcf857x i2c gpio expander support

This is a new-style I2C driver for most common 8 and 16 bit I2C based
"quasi-bidirectional" GPIO expanders: pcf8574 or pcf8575, and several
compatible models (mostly faster, supporting I2C at up to 1 MHz).

The driver exposes the GPIO signals using the platform-neutral GPIO
programming interface, so they are easily accessed by other kernel code.  The
lack of such a flexible kernel API has been a big factor in the proliferation
of board-specific drivers for these chips...  stuff that rarely makes it
upstream since it's so ugly.  This driver will let such boards use standard
calls.

Since it's a new-style driver, these devices must be configured as part of
board-specific init.  That eliminates the need for error-prone manual
configuration of module parameters, and makes compatibility with legacy
drivers (pcf8574.c, pc8575.c) for these chips easier (there's a clear
either/or disjunction).

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>
Acked-by: Jean Delvare <khali@linux-fr.org>
Cc: Eric Miao <eric.miao@marvell.com>
Cc: Sam Ravnborg <sam@ravnborg.org>
Cc: Haavard Skinnemoen <hskinnemoen@atmel.com>
Cc: Philipp Zabel <philipp.zabel@gmail.com>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Ben Gardner <bgardner@wabtec.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
drivers/gpio/Kconfig
drivers/gpio/Makefile
drivers/gpio/pcf857x.c [new file with mode: 0644]
include/linux/i2c/pcf857x.h [new file with mode: 0644]