acpi: Add a method to write tables for a device

A device may want to write out ACPI tables to describe itself to Linux.
Add a method to permit this.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Wolfgang Wallner <wolfgang.wallner@br-automation.com>
diff --git a/drivers/core/acpi.c b/drivers/core/acpi.c
index ba50d68..e09905c 100644
--- a/drivers/core/acpi.c
+++ b/drivers/core/acpi.c
@@ -11,8 +11,17 @@
 #include <common.h>
 #include <dm.h>
 #include <dm/acpi.h>
+#include <dm/device-internal.h>
 #include <dm/root.h>
 
+/* Type of method to call */
+enum method_t {
+	METHOD_WRITE_TABLES,
+};
+
+/* Prototype for all methods */
+typedef int (*acpi_method)(const struct udevice *dev, struct acpi_ctx *ctx);
+
 int acpi_copy_name(char *out_name, const char *name)
 {
 	strncpy(out_name, name, ACPI_NAME_LEN);
@@ -31,3 +40,56 @@
 
 	return -ENOSYS;
 }
+
+acpi_method acpi_get_method(struct udevice *dev, enum method_t method)
+{
+	struct acpi_ops *aops;
+
+	aops = device_get_acpi_ops(dev);
+	if (aops) {
+		switch (method) {
+		case METHOD_WRITE_TABLES:
+			return aops->write_tables;
+		}
+	}
+
+	return NULL;
+}
+
+int acpi_recurse_method(struct acpi_ctx *ctx, struct udevice *parent,
+			enum method_t method)
+{
+	struct udevice *dev;
+	acpi_method func;
+	int ret;
+
+	func = acpi_get_method(parent, method);
+	if (func) {
+		log_debug("\n");
+		log_debug("- %s %p\n", parent->name, func);
+		ret = device_ofdata_to_platdata(parent);
+		if (ret)
+			return log_msg_ret("ofdata", ret);
+		ret = func(parent, ctx);
+		if (ret)
+			return log_msg_ret("func", ret);
+	}
+	device_foreach_child(dev, parent) {
+		ret = acpi_recurse_method(ctx, dev, method);
+		if (ret)
+			return log_msg_ret("recurse", ret);
+	}
+
+	return 0;
+}
+
+int acpi_write_dev_tables(struct acpi_ctx *ctx)
+{
+	int ret;
+
+	log_debug("Writing device tables\n");
+	ret = acpi_recurse_method(ctx, dm_root(), METHOD_WRITE_TABLES);
+	log_debug("Writing finished, err=%d\n", ret);
+
+	return ret;
+}