dm: Add a No-op uclass

This uclass is intended for devices that do not need any features from the
uclass, including binding children.
This will typically be used by devices that are used to bind child devices
but do not use dm_scan_fdt_dev() to do it. That is for example the case of
several USB wrappers that have 2 child devices (1 for device and 1 for
host) but bind only one at a any given time.

Signed-off-by: Jean-Jacques Hiblot <jjhiblot@ti.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 74 insertions, 0 deletions

diff --git a/test/dm/Makefile b/test/dm/Makefile
index 49857c5092..aeb3aa0ca7 100644
--- a/test/dm/Makefile
+++ b/test/dm/Makefile
@@ -3,6 +3,7 @@
 # Copyright (c) 2013 Google, Inc
 
 obj-$(CONFIG_UT_DM) += bus.o
+obj-$(CONFIG_UT_DM) += nop.o
 obj-$(CONFIG_UT_DM) += test-driver.o
 obj-$(CONFIG_UT_DM) += test-fdt.o
 obj-$(CONFIG_UT_DM) += test-main.o
diff --git a/test/dm/nop.c b/test/dm/nop.c
new file mode 100644
index 0000000000..2df29f3d15
--- /dev/null
+++ b/test/dm/nop.c
@@ -0,0 +1,73 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Test for the NOP uclass
+ *
+ * (C) Copyright 2019 - Texas Instruments Incorporated - http://www.ti.com/
+ * Jean-Jacques Hiblot <jjhiblot@ti.com>
+ */
+
+#include <common.h>
+#include <dm.h>
+#include <dm/ofnode.h>
+#include <dm/lists.h>
+#include <dm/device.h>
+#include <dm/test.h>
+#include <misc.h>
+#include <test/ut.h>
+
+static int noptest_bind(struct udevice *parent)
+{
+	ofnode ofnode = dev_read_first_subnode(parent);
+
+	while (ofnode_valid(ofnode)) {
+		struct udevice *dev;
+		const char *bind_flag = ofnode_read_string(ofnode, "bind");
+
+		if (bind_flag && (strcmp(bind_flag, "True") == 0))
+			lists_bind_fdt(parent, ofnode, &dev, false);
+		ofnode = dev_read_next_subnode(ofnode);
+	}
+
+	return 0;
+}
+
+static const struct udevice_id noptest1_ids[] = {
+	{
+		.compatible = "sandbox,nop_sandbox1",
+	},
+	{ }
+};
+
+U_BOOT_DRIVER(noptest_drv1) = {
+	.name	= "noptest1_drv",
+	.of_match	= noptest1_ids,
+	.id	= UCLASS_NOP,
+	.bind = noptest_bind,
+};
+
+static const struct udevice_id noptest2_ids[] = {
+	{
+		.compatible = "sandbox,nop_sandbox2",
+	},
+	{ }
+};
+
+U_BOOT_DRIVER(noptest_drv2) = {
+	.name	= "noptest2_drv",
+	.of_match	= noptest2_ids,
+	.id	= UCLASS_NOP,
+};
+
+static int dm_test_nop(struct unit_test_state *uts)
+{
+	struct udevice *dev;
+
+	ut_assertok(uclass_get_device_by_name(UCLASS_NOP, "nop-test_0", &dev));
+	ut_assertok(uclass_get_device_by_name(UCLASS_NOP, "nop-test_1", &dev));
+	ut_asserteq(-ENODEV,
+		    uclass_get_device_by_name(UCLASS_NOP, "nop-test_2", &dev));
+
+	return 0;
+}
+
+DM_TEST(dm_test_nop, DM_TESTF_FLAT_TREE | DM_TESTF_SCAN_FDT);