From: David Brownell Date: Tue, 5 Feb 2008 06:28:24 +0000 (-0800) Subject: gpiolib: pcf857x i2c gpio expander support X-Git-Tag: v2.6.25-rc1~992 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=15fae37d9f5f21571a9618d8353164b6ddfea6f6;p=pandora-kernel.git 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 Acked-by: Jean Delvare Cc: Eric Miao Cc: Sam Ravnborg Cc: Haavard Skinnemoen Cc: Philipp Zabel Cc: Russell King Cc: Ben Gardner Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- Reading git-diff-tree failed