[coreboot-gerrit] New patch to review for coreboot: acpi_device: Add special HID for DT namespace

[Furquan Shaikh (furquan@google.com)]

Furquan Shaikh (furquan at google.com) just uploaded a new patch set to gerrit, which you can find at https://review.coreboot.org/17842

-gerrit

commit e2cd9362ad215158f937e2b9a01cffa294abfa19
Author: Furquan Shaikh <furquan at chromium.org>
Date:   Tue Dec 13 09:43:46 2016 -0800

    acpi_device: Add special HID for DT namespace
    
    BUG=chrome-os-partner:60194
    BRANCH=None
    TEST=Compiles successfully
    
    Change-Id: I0fe146cf2235c7c4ad3ea5589ed556884de3a368
    Signed-off-by: Furquan Shaikh <furquan at chromium.org>
---
 src/arch/x86/include/arch/acpi_device.h | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/src/arch/x86/include/arch/acpi_device.h b/src/arch/x86/include/arch/acpi_device.h
index b0285d2..6e8f812 100644
--- a/src/arch/x86/include/arch/acpi_device.h
+++ b/src/arch/x86/include/arch/acpi_device.h
@@ -24,6 +24,18 @@
 #define ACPI_DESCRIPTOR_GPIO		(ACPI_DESCRIPTOR_LARGE | 12)
 #define ACPI_DESCRIPTOR_SERIAL_BUS	(ACPI_DESCRIPTOR_LARGE | 14)
 
+/*
+ * PRP0001 is a special DT namespace link device ID. It provides a means to use
+ * existing DT-compatible device identification in ACPI. When this _HID is used
+ * by an ACPI device, the ACPI subsystem in OS looks up "compatible" property in
+ * device object's _DSD and will use the value of that property to identify the
+ * corresponding device in analogy with the original DT device identification
+ * algorithm.
+ * More details can be found in Linux kernel documentation:
+ * Documentation/acpi/enumeration.txt
+ */
+#define ACPI_DT_NAMESPACE_HID		"PRP0001"
+
 struct device;
 const char *acpi_device_name(struct device *dev);
 const char *acpi_device_path(struct device *dev);