At Sun, 02/02/2025 at 18:09 +0100, Philippe Mathieu-Daudé writes: > No clue about compatibility. If you unfortunately need to add it, > then please address my comments in the next version. TCA6416 is _way_ more complex device than PCF8574. Basically PCF8574 is shift register directly connected to IO lines, while TCA6416 is more like fully-fledged GPIO controller with output direction, drive strength, interrupt mask configuration etc etc.
In Linux kernel these devices are handled by family-compatible driver drivers/gpio/gpio-pca953x.c Closest things by implementation in QEMU source tree are hw/gpio/pca9552.c and hw/gpio/pca9554.c However they are NOT register-compatible with pca953x. I suppose, best decision would be new driver for TCA6416 which eventually should support whole pca953x family of I2C GPIO expanders. Best regards, Dmitrii
