gpiolib: pca9539 i2c gpio expander support
This adds a new-style I2C driver with basic support for the sixteen bit
PCA9539 GPIO expanders. These chips have multiple registers, push-pull output
drivers, and (not supported in this patch) pin change interrupts.
Board-specific code must provide "pca9539_platform_data" with each chip's
"i2c_board_info". That provides the GPIO numbers to be used by that chip, and
callbacks for board-specific setup/teardown logic.
Derived from drivers/i2c/chips/pca9539.c (which has no current known users).
This is faster and simpler; it uses 16-bit register access, and cache the
OUTPUT and DIRECTION registers for fast access
Signed-off-by: eric miao <[email protected]>
Signed-off-by: David Brownell <[email protected]>
Acked-by: Jean Delvare <[email protected]>
Cc: Sam Ravnborg <[email protected]>
Cc: Haavard Skinnemoen <[email protected]>
Cc: Philipp Zabel <[email protected]>
Cc: Russell King <[email protected]>
Cc: Ben Gardner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
4 files changed
