Messages in this thread | | | Subject | Re: [PATCH v2 1/3] dt-bindings: gpio: Add binding documentation for gpio-thunderx | From | David Daney <> | Date | Mon, 9 Jan 2017 11:44:22 -0800 |
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On 01/09/2017 11:36 AM, Linus Walleij wrote: > On Sat, Jan 7, 2017 at 12:22 AM, David Daney <ddaney.cavm@gmail.com> wrote: > >> From: David Daney <david.daney@cavium.com> >> >> Signed-off-by: David Daney <david.daney@cavium.com> > (...) > >> +Optional Properties: >> +- compatible: "cavium,thunder-8890-gpio", unused as PCI driver binding is used. >> +- interrupt-controller: Marks the device node as an interrupt controller. >> +- #interrupt-cells: Must be present and have value of 2 if >> + "interrupt-controller" is present. >> + - First cell is the GPIO pin number relative to the controller. >> + - Second cell is triggering flags as defined in interrupts.txt. > > AFAICT this device has an optional list of interrupts as well? > One per pin even?
I'm not sure I understand your question.
The GPIO hardware supports an interrupt on each pin. The underlying interrupt mechanism is via PCI MSI-X, which are fully discoverable by the driver, so lack of device tree binding for the these underlying MSI-X is fully appropriate. On the other hand, users of the GPIO interrupt pins need this "interrupt-controller" and "#interrupt-cells" to be able to properly find and configure the proper interrupts.
I said the "interrupt-controller" property was optional, because some systems don't use GPIO interrupts and can function without specifying that it is also an interrupt controller.
> > Yours, > Linus Walleij >
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