On Thu, Mar 29, 2018 at 10:29 PM, H. Nikolaus Schaller
[off-list ref] wrote:

Another issue I have fixed is that the pcal6524 has 4 registers per
bank while the pcal9555a has only 2.

So, you mean it's still in non-working case in Linus' tree?
Please, send patches!

This is encoded in the address
constants for the new "L"-registers and has to be taken care of in
pca953x_read_regs_24() and pca953x_write_regs_24().

But I still have another problem:

[    4.808823] pca953x 4-0022: irq 186: unsupported type 8
[    4.814303] genirq: Setting trigger mode 8 for irq 186 failed (pca953x_irq_set_type+0x0/0xa8)

This comes from https://elixir.bootlin.com/linux/v4.16-rc7/source/sound/soc/codecs/ts3a227e.c#L314

It appears that the pca953x driver/interrupt-controller can't handle
IRQF_TRIGGER_LOW, but that is hard coded into the ts3a227 driver.

Anyone with knowledge and help about this issue?

This is easy to fix (not read datasheet for better solution though):
emulate it via FALLING (LOW) and RISING (HIGH).


-- 
With Best Regards,
Andy Shevchenko