acpi: Add a function to get a device path and scope

Add a function to build up the ACPI path for a device and another for its
scope.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

1 files changed, 44 insertions, 0 deletions

diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
new file mode 100644
index 0000000000..37a675f101
--- /dev/null
+++ b/include/acpi/acpi_device.h
@@ -0,0 +1,44 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+/*
+ * Generation of tables for particular device types
+ *
+ * Copyright 2019 Google LLC
+ * Mostly taken from coreboot file of the same name
+ */
+
+#ifndef __ACPI_DEVICE_H
+#define __ACPI_DEVICE_H
+
+struct udevice;
+
+/* Length of a full path to an ACPI device */
+#define ACPI_PATH_MAX		30
+
+/**
+ * acpi_device_path() - Get the full path to an ACPI device
+ *
+ * This gets the full path in the form XXXX.YYYY.ZZZZ where XXXX is the root
+ * and ZZZZ is the device. All parent devices are added to the path.
+ *
+ * @dev: Device to check
+ * @buf: Buffer to place the path in (should be ACPI_PATH_MAX long)
+ * @maxlen: Size of buffer (typically ACPI_PATH_MAX)
+ * @return 0 if OK, -ve on error
+ */
+int acpi_device_path(const struct udevice *dev, char *buf, int maxlen);
+
+/**
+ * acpi_device_scope() - Get the scope of an ACPI device
+ *
+ * This gets the scope which is the full path of the parent device, as per
+ * acpi_device_path().
+ *
+ * @dev: Device to check
+ * @buf: Buffer to place the path in (should be ACPI_PATH_MAX long)
+ * @maxlen: Size of buffer (typically ACPI_PATH_MAX)
+ * @return 0 if OK, -EINVAL if the device has no parent, other -ve on other
+ *	error
+ */
+int acpi_device_scope(const struct udevice *dev, char *scope, int maxlen);
+
+#endif