On Mon, Feb 11, 2019 at 11:01:12AM -0800, egranata@xxxxxxxxxxxx wrote: > From: Enrico Granata <egranata@xxxxxxxxxxxx> > > ACPI 5 added support for GpioInt resources as a way to provide > information about interrupts mediated via a GPIO controller. > > Several device buses (e.g. SPI, I2C) have support for retrieving > an IRQ specified via this type of resource, and providing it > directly to the driver as an IRQ number. > > This is not currently done for the platform drivers, as platform_get_irq() > does not try to parse GpioInt() resources. This requires drivers to > either have to support only one possible IRQ resource, or to have code > in place to try both as a failsafe. > > While there is a possibility of ambiguity for devices that exposes > multiple IRQs, it is easy and feasible to support the common case > of devices that only expose one IRQ which would be of either type > depending on the underlying system's architecture. > > This commit adds support for parsing a GpioInt resource in order > to fulfill a request for the index 0 IRQ for a platform device. > Yes, let's go this way as a compromise to get major of the cases working. Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx> > Signed-off-by: Enrico Granata <egranata@xxxxxxxxxxxx> > --- > Changes in v2: > - only support IRQ index 0 > > drivers/base/platform.c | 15 ++++++++++++++- > 1 file changed, 14 insertions(+), 1 deletion(-) > > diff --git a/drivers/base/platform.c b/drivers/base/platform.c > index 1c958eb33ef4d..0d3611cd1b3bc 100644 > --- a/drivers/base/platform.c > +++ b/drivers/base/platform.c > @@ -127,7 +127,20 @@ int platform_get_irq(struct platform_device *dev, unsigned int num) > irqd_set_trigger_type(irqd, r->flags & IORESOURCE_BITS); > } > > - return r ? r->start : -ENXIO; > + if (r) > + return r->start; > + > + /* > + * For the index 0 interrupt, allow falling back to GpioInt > + * resources. While a device could have both Interrupt and GpioInt > + * resources, making this fallback ambiguous, in many common cases > + * the device will only expose one IRQ, and this fallback > + * allows a common code path across either kind of resource. > + */ > + if (num == 0 && has_acpi_companion(&dev->dev)) > + return acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num); > + > + return -ENXIO; > #endif > } > EXPORT_SYMBOL_GPL(platform_get_irq); > -- > 2.20.1.791.gb4d0f1c61a-goog > -- With Best Regards, Andy Shevchenko
