This is an I2C driver for the Awinic AW9523B I/O expander. As well
as the supporting usual digital I/Os, this device features the
ability to drive LEDs directly, and can control the drive current
to each LED individually. The driver was derived from the PCA9555
driver, provides all the standard interfaces of an i/o expander
driver. It also features support for the special features of the
AW9523B through pin direction IOEXPANDER_DIRECTION_OUT_LED and
IOEXPANDER_OPTION_NONGENERIC with AW9523B_OPTION_* options.
The driver has a number of configurable features including interrupt
handling and a shadow register mode based on the PCA9555 driver,
plus new LED/dimming support.
Testing was done using an ESP32S3 host and I2C connection to the
Adafruit AW9523 breakout board.
Signed-off-by: Zik Saleeba <zik@zikzak.net>