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authorEnrico Granata <egranata@chromium.org>2019-02-11 22:01:12 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2019-02-12 12:36:49 +0300
commitdaaef255dc96834aaaad627d3271504cba3ac2dc (patch)
tree7aca979c0f93f168e293a0b941e510e575abec6f /drivers/base
parent4417967bf2479020652049155c11a2d5b3a0136e (diff)
downloadlinux-daaef255dc96834aaaad627d3271504cba3ac2dc.tar.xz
driver: platform: Support parsing GpioInt 0 in platform_get_irq()
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@chromium.org> Reviewed-by: Dmitry Torokhov <dtor@chromium.org> Acked-by: Hans de Goede <hdegoede@redhat.com> Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/base')
-rw-r--r--drivers/base/platform.c15
1 files changed, 14 insertions, 1 deletions
diff --git a/drivers/base/platform.c b/drivers/base/platform.c
index 1c958eb33ef4..0d3611cd1b3b 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);