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authorMatthew Garrett <mjg@redhat.com>2012-05-11 16:08:26 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2012-05-11 17:03:12 -0700
commit38ac0f1b90dc9486cc039f1a4d8b0202813e5b67 (patch)
tree906f48f2bfb685d6075b74f50bc338768014ca3e /drivers/acpi/utils.c
parent66886d6f8c9bcdee3d7fce5796dcffd6b4bc0b48 (diff)
downloadop-kernel-dev-38ac0f1b90dc9486cc039f1a4d8b0202813e5b67.zip
op-kernel-dev-38ac0f1b90dc9486cc039f1a4d8b0202813e5b67.tar.gz
ACPI: Add _PLD support
Add a simple helper function to allow drivers to obtain the physical device location data. Acked-by: Len Brown <len.brown@intel.com> Signed-off-by: Matthew Garrett <mjg@redhat.com> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/acpi/utils.c')
-rw-r--r--drivers/acpi/utils.c30
1 files changed, 30 insertions, 0 deletions
diff --git a/drivers/acpi/utils.c b/drivers/acpi/utils.c
index b002a47..adbbc1c 100644
--- a/drivers/acpi/utils.c
+++ b/drivers/acpi/utils.c
@@ -382,3 +382,33 @@ acpi_evaluate_reference(acpi_handle handle,
}
EXPORT_SYMBOL(acpi_evaluate_reference);
+
+acpi_status
+acpi_get_physical_device_location(acpi_handle handle, struct acpi_pld *pld)
+{
+ acpi_status status;
+ struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL };
+ union acpi_object *output;
+
+ status = acpi_evaluate_object(handle, "_PLD", NULL, &buffer);
+
+ if (ACPI_FAILURE(status))
+ return status;
+
+ output = buffer.pointer;
+
+ if (!output || output->type != ACPI_TYPE_PACKAGE
+ || !output->package.count
+ || output->package.elements[0].type != ACPI_TYPE_BUFFER
+ || output->package.elements[0].buffer.length > sizeof(*pld)) {
+ status = AE_TYPE;
+ goto out;
+ }
+
+ memcpy(pld, output->package.elements[0].buffer.pointer,
+ output->package.elements[0].buffer.length);
+out:
+ kfree(buffer.pointer);
+ return status;
+}
+EXPORT_SYMBOL(acpi_get_physical_device_location);
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