[PATCH 0/2] leds: pca955x: Expose GPIOs for all pins
joel at jms.id.au
Mon Feb 21 18:33:59 AEDT 2022
On Fri, 24 Sept 2021 at 06:41, Cédric Le Goater <clg at kaod.org> wrote:
> On 9/21/21 06:39, Andrew Jeffery wrote:
> > Without these patches the driver limits the number of pins exposed on
> > the gpiochip to the number of pins specified as GPIO in the devicetree,
> > but doesn't map between the GPIO and pin number spaces. The result is
> > that specifying offset or interleaved GPIOs in the devicetree gives
> > unexpected behaviour in userspace.
> > By always exposing all pins as GPIOs the patches resolve the lack of
> > mapping between GPIO offsets and pins on the package in the driver by
> > ensuring we always have a 1-to-1 mapping.
> > The issue is primarily addressed by patch 1/2. Patch 2/2 makes it
> > possible to not expose any pins as LEDs (and therefore make them all
> > accessible as GPIOs). This has a follow-on effect of allowing the driver
> > to bind to a device instantiated at runtime without requiring a
> > description in the devicetree.
> > I've tested the series under qemu to inspect the various interactions
> > between LEDs vs GPIOs as well as conflicting GPIO requests.
> > Please review!
> This is simpler than the 'ngpio' business we had before.
> Reviewed-by: Cédric Le Goater <clg at kaod.org>
I saw that you recently merged some LED patches. I was wondering if
you could consider this series for v5.18. It still applies cleanly,
and we've been running it for a while now, so it's very well tested.
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