dm: core: Add support for simple-bus

Add a driver for the simple-bus nodes, which allows devices within these
nodes to be bound.

Signed-off-by: Simon Glass <sjg@chromium.org>

drivers/core/Makefile

@@ -5,3 +5,4 @@
 #
 
 obj-y := device.o lists.o root.o uclass.o util.o
+obj-$(CONFIG_OF_CONTROL) += simple-bus.o

drivers/core/simple-bus.c

@@ -0,0 +1,33 @@
+/*
+ * Copyright (c) 2014 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/root.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int simple_bus_post_bind(struct udevice *dev)
+{
+	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
+}
+
+UCLASS_DRIVER(simple_bus) = {
+	.id		= UCLASS_SIMPLE_BUS,
+	.name		= "simple_bus",
+	.post_bind	= simple_bus_post_bind,
+};
+
+static const struct udevice_id generic_simple_bus_ids[] = {
+	{ .compatible = "simple-bus" },
+	{ }
+};
+
+U_BOOT_DRIVER(simple_bus_drv) = {
+	.name	= "generic_simple_bus",
+	.id	= UCLASS_SIMPLE_BUS,
+	.of_match = generic_simple_bus_ids,
+};

include/dm/uclass-id.h

@@ -19,6 +19,7 @@ enum uclass_id {
 	UCLASS_TEST_FDT,
 	UCLASS_TEST_BUS,
 	UCLASS_SPI_EMUL,	/* sandbox SPI device emulator */
+	UCLASS_SIMPLE_BUS,
 
 	/* U-Boot uclasses start here */
 	UCLASS_GPIO,		/* Bank of general-purpose I/O pins */