The chip PCA9538 is a 8 bit I/O expander connected to the systems I2C
bus. Add a chip driver to support this chip.
Beside the pure chip driver two interface functions are provided to read
the state of the pins and write output values to the pins.
As the slave address of this chip is hardware configurable the function
pca9538_get_dev() is used to get the right slave address. This function
needs to be implemented in mainboard code if one needs to use the
interface functions to read and write I/O state.
Change-Id: Ic856123b4f4c8b721928ee3a2a4bb37833ea4b20
Signed-off-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-on: https://review.coreboot.org/23748
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
