acpi: Add a way to check device status

At present U-Boot does not support the different ACPI status values, but
it is best to put this logic in a central place. Add a function to get the
device status.

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>
diff --git a/include/acpi/acpi_device.h b/include/acpi/acpi_device.h
index 37a675f..09c2274 100644
--- a/include/acpi/acpi_device.h
+++ b/include/acpi/acpi_device.h
@@ -9,11 +9,28 @@
 #ifndef __ACPI_DEVICE_H
 #define __ACPI_DEVICE_H
 
+#include <linux/bitops.h>
+
 struct udevice;
 
 /* Length of a full path to an ACPI device */
 #define ACPI_PATH_MAX		30
 
+/* Values that can be returned for ACPI device _STA method */
+enum acpi_dev_status {
+	ACPI_DSTATUS_PRESENT		= BIT(0),
+	ACPI_DSTATUS_ENABLED		= BIT(1),
+	ACPI_DSTATUS_SHOW_IN_UI		= BIT(2),
+	ACPI_DSTATUS_OK			= BIT(3),
+	ACPI_DSTATUS_HAS_BATTERY	= BIT(4),
+
+	ACPI_DSTATUS_ALL_OFF	= 0,
+	ACPI_DSTATUS_HIDDEN_ON	= ACPI_DSTATUS_PRESENT | ACPI_DSTATUS_ENABLED |
+		ACPI_DSTATUS_OK,
+	ACPI_DSTATUS_ALL_ON	= ACPI_DSTATUS_HIDDEN_ON |
+		ACPI_DSTATUS_SHOW_IN_UI,
+};
+
 /**
  * acpi_device_path() - Get the full path to an ACPI device
  *
@@ -41,4 +58,15 @@
  */
 int acpi_device_scope(const struct udevice *dev, char *scope, int maxlen);
 
+/**
+ * acpi_device_status() - Get the status of a device
+ *
+ * This currently just returns ACPI_DSTATUS_ALL_ON. It does not support
+ * inactive or hidden devices.
+ *
+ * @dev: Device to check
+ * @return device status, as ACPI_DSTATUS_...
+ */
+enum acpi_dev_status acpi_device_status(const struct udevice *dev);
+
 #endif