dm: Provide a function to scan child FDT nodes

At present only root nodes in the device tree are scanned for devices.
But some devices can have children. For example a SPI bus may have
several children for each of its chip selects.

Add a function which scans subnodes and binds devices for each one. This
can be used for the root node scan also, so change it.

A device can call this function in its bind() or probe() methods to bind
its children.

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

1 files changed, 63 insertions, 0 deletions

diff --git a/test/dm/bus.c b/test/dm/bus.c
new file mode 100644
index 0000000..cfb9934
--- /dev/null
+++ b/test/dm/bus.c
@@ -0,0 +1,63 @@
+/*
+ * Copyright (c) 2014 Google, Inc
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/root.h>
+#include <dm/test.h>
+#include <dm/ut.h>
+#include <dm/util.h>
+
+DECLARE_GLOBAL_DATA_PTR;
+
+static int testbus_drv_probe(struct udevice *dev)
+{
+	return dm_scan_fdt_node(dev, gd->fdt_blob, dev->of_offset, false);
+}
+
+static const struct udevice_id testbus_ids[] = {
+	{
+		.compatible = "denx,u-boot-test-bus",
+		.data = DM_TEST_TYPE_FIRST },
+	{ }
+};
+
+U_BOOT_DRIVER(testbus_drv) = {
+	.name	= "testbus_drv",
+	.of_match	= testbus_ids,
+	.id	= UCLASS_TEST_BUS,
+	.probe	= testbus_drv_probe,
+	.priv_auto_alloc_size = sizeof(struct dm_test_priv),
+	.platdata_auto_alloc_size = sizeof(struct dm_test_pdata),
+};
+
+UCLASS_DRIVER(testbus) = {
+	.name		= "testbus",
+	.id		= UCLASS_TEST_BUS,
+};
+
+/* Test that we can probe for children */
+static int dm_test_bus_children(struct dm_test_state *dms)
+{
+	int num_devices = 4;
+	struct udevice *bus;
+	struct uclass *uc;
+
+	ut_assertok(uclass_get(UCLASS_TEST_FDT, &uc));
+	ut_asserteq(num_devices, list_count_items(&uc->dev_head));
+
+	/* Probe the bus, which should yield 3 more devices */
+	ut_assertok(uclass_get_device(UCLASS_TEST_BUS, 0, &bus));
+	num_devices += 3;
+
+	ut_assertok(uclass_get(UCLASS_TEST_FDT, &uc));
+	ut_asserteq(num_devices, list_count_items(&uc->dev_head));
+
+	ut_assert(!dm_check_devices(dms, num_devices));
+
+	return 0;
+}
+DM_TEST(dm_test_bus_children, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);