Re: [PATCH 0/3] pinctrl: mcp23s08: Fixups for mcp23x17

[Rob Herring]

On Fri, Aug 14, 2020 at 02:56:54PM +0100, Thomas Preston wrote:
> On 14/08/2020 11:03, Thomas Preston wrote:
> > I'm in the process of adding a device tree overlay for the PiFace
> > Digital Raspberry Pi daughter board [0]. It's an mcp23s17 SPI GPIO port
> > expander. In doing so, I noticed some errors with the mcp23s08 driver.
> [snip]
> > They're quite trivial and backwards compatible, although I might be
> > wrong about "interrupt-controller". Can someone please confirm?
> [snip]
> > [0] https://github.com/raspberrypi/linux/pull/3794
> 
> Actually I think I'm wrong about the interrupt-controller changes in patches
> 0002 and 0003.

You are. Looking at the datasheet, the GPIOs have interrupt capability. 
GPIO controllers are typically both an interrupt client and provider.

Rob