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. Signed-off-by: Enrico Granata <egranata@xxxxxxxxxxxx> --- Changes in v3: - ensured that -ENOENT return from acpi_dev_gpio_irq_get is not propagated upwards, as some drivers expect platform_get_irq to return either a valid IRQ or -ENXIO and will break otherwise drivers/base/platform.c | 19 ++++++++++++++++++- 1 file changed, 18 insertions(+), 1 deletion(-) diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 1c958eb33ef4d..afd8b916303e4 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -127,7 +127,24 @@ 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)) { + int ret = acpi_dev_gpio_irq_get(ACPI_COMPANION(&dev->dev), num); + + if (ret > 0 || ret == -EPROBE_DEFER) + return ret; + } + + return -ENXIO; #endif } EXPORT_SYMBOL_GPL(platform_get_irq); -- 2.21.0.rc0.258.g878e2cd30e-goog