Hi, I just came across a chip by NXP which seems to be a modernized replacement of the tca6424.

After a quick look into the data sheets, it seems to have: * the same package * same pin assignment * same basic functions * same registers 0-15 * additional registers 16-31 * better interrupt / latch / debounce handling

Generally this could solve some IRQ extension problems with the ts3a227 because the tca6424 may trigger interrupts if a pin is changed from input to output. And, it reports any interrupt change and resets them in parallel, so that there is a general risk to loose interrupts.

There is not yet code in Linux but it is very likely a simple extension of the pca953x driver.

Since the chip seems to be a drop-in replacement, it is quite simple to test it on a modified V5.1.3 mainboard.

What do you think?

BR, Nikolaus

http://elixir.free-electrons.com/linux/v4.14-rc1/source/Documentation/device... https://www.nxp.com/docs/en/data-sheet/PCAL6524.pdf http://www.ti.com/lit/ds/symlink/tca6424a.pdf