clk: Add kunit tests for fixed rate and parent data

We'd like to apply overlays to the root node in KUnit so we can test platform devices created as children of the root node.

On some architectures (powerpc), the root node isn't marked with OF_POPULATED_BUS. If an overlay tries to modify the root node on these platforms it will fail, while on other platforms, such as ARM, it will succeed. This is because the root node is marked with OF_POPULATED_BUS by of_platform_default_populate_init() calling of_platform_default_populate() with NULL as the first argument.

Loosen the requirement here so that platform devices can be created for nodes created as children of the root node via DT overlays even if the platform bus wasn't populated for the root node.

Cc Rob Herring <[email protected]>

Cc Saravana Kannan <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---
 drivers/of/platform.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Add test managed wrappers for of_overlay_apply() that automatically removes the overlay when the test is finished. This API is intended for use by KUnit tests that test code which relies on 'struct device_node's and of_*() APIs.

KUnit tests will call of_overlay_apply_kunit() to load an overlay that's been built into the kernel image. When the test is complete, the overlay will be removed.

This has a few benefits:

1) It keeps the tests hermetic because the overlay is removed when the test is complete. Tests won't even be aware that an overlay was loaded in another test.

2) The overlay code can live right next to the unit test that loads it. The overlay and the unit test can be compiled into one kernel module if desired.

3) We can test different device tree configurations by loading different overlays. The overlays can be written for a specific test, and there can be many of them loaded per-test without needing to jam all possible combinations into one DTB.

4) It also allows KUnit to test device tree dependent code on any architecture, not just UML. This allows KUnit tests to test architecture specific device tree code.

There are some potential pitfalls though. Test authors need to be careful to not overwrite properties in the live tree. The easiest way to do this is to add and remove nodes with a 'kunit-' prefix, almost guaranteeing that the same node won't be present in the tree loaded at boot.

Suggested-by Rob Herring <[email protected]>

Cc Rob Herring <[email protected]>

Cc Saravana Kannan <[email protected]>

Reviewed-by Rob Herring (Arm) <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---

 Documentation/dev-tools/kunit/api/index.rst |  11 ++
 Documentation/dev-tools/kunit/api/of.rst    |  13 +++
 drivers/of/Makefile                         |   1 +
 drivers/of/of_kunit_helpers.c               |  74 +++++++++++++
 include/kunit/of.h                          | 115 ++++++++++++++++++++
 5 files changed, 214 insertions(+)
 create mode 100644 Documentation/dev-tools/kunit/api/of.rst
 create mode 100644 drivers/of/of_kunit_helpers.c
 create mode 100644 include/kunit/of.h

Documentation/dev-tools/kunit/api/index.rst +11 -0

index 2d8f756aab56..282befa17edf 100644
@@ -9,11 +9,15 @@ API Reference
        test
        resource
        functionredirection
+       of
 
 
 This page documents the KUnit kernel testing API. It is divided into the
 following sections:
 
+Core KUnit API
+==============
+
 Documentation/dev-tools/kunit/api/test.rst
 
  - Documents all of the standard testing API

@@ -25,3 +29,10 @@ Documentation/dev-tools/kunit/api/resource.rst
 Documentation/dev-tools/kunit/api/functionredirection.rst
 
  - Documents the KUnit Function Redirection API
+
+Driver KUnit API
+================
+
+Documentation/dev-tools/kunit/api/of.rst
+
+ - Documents the KUnit device tree (OF) API

Documentation/dev-tools/kunit/api/of.rst new file +13 -0

new file mode 100644
index 000000000000..cb4193dcddbb
@@ -0,0 +1,13 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================
+Device Tree (OF) API
+====================
+
+The KUnit device tree API is used to test device tree (of_*) dependent code.
+
+.. kernel-doc:: include/kunit/of.h
+   :internal:
+
+.. kernel-doc:: drivers/of/of_kunit_helpers.c
+   :export:

drivers/of/Makefile +1 -0

index 251d33532148..2ae909adde49 100644
@@ -19,6 +19,7 @@ obj-y += kexec.o
 endif
 endif
 
+obj-$(CONFIG_KUNIT) += of_kunit_helpers.o
 obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
 
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/

drivers/of/of_kunit_helpers.c new file +74 -0

new file mode 100644
index 000000000000..8a09132e32a8
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test managed device tree APIs
+ */
+
+#include <linux/of.h>
+#include <linux/of_fdt.h>
+
+#include <kunit/of.h>
+#include <kunit/test.h>
+#include <kunit/resource.h>
+
+#if defined(CONFIG_OF_OVERLAY) && defined(CONFIG_OF_EARLY_FLATTREE)
+
+static void of_overlay_fdt_apply_kunit_exit(void *ovcs_id)
+{
+       of_overlay_remove(ovcs_id);
+}
+
+/**
+ * of_overlay_fdt_apply_kunit() - Test managed of_overlay_fdt_apply()
+ * @test: test context
+ * @overlay_fdt: device tree overlay to apply
+ * @overlay_fdt_size: size in bytes of @overlay_fdt
+ * @ovcs_id: identifier of overlay, used to remove the overlay
+ *
+ * Just like of_overlay_fdt_apply(), except the overlay is managed by the test
+ * case and is automatically removed with of_overlay_remove() after the test
+ * case concludes.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+int of_overlay_fdt_apply_kunit(struct kunit *test, void *overlay_fdt,
+                              u32 overlay_fdt_size, int *ovcs_id)
+{
+       int ret;
+       int *copy_id;
+
+       copy_id = kunit_kmalloc(test, sizeof(*copy_id), GFP_KERNEL);
+       if (!copy_id)
+               return -ENOMEM;
+
+       ret = of_overlay_fdt_apply(overlay_fdt, overlay_fdt_size,
+                                  ovcs_id, NULL);
+       if (ret)
+               return ret;
+
+       *copy_id = *ovcs_id;
+
+       return kunit_add_action_or_reset(test, of_overlay_fdt_apply_kunit_exit,
+                                        copy_id);
+}
+EXPORT_SYMBOL_GPL(of_overlay_fdt_apply_kunit);
+
+#endif
+
+KUNIT_DEFINE_ACTION_WRAPPER(of_node_put_wrapper, of_node_put, struct device_node *);
+
+/**
+ * of_node_put_kunit() - Test managed of_node_put()
+ * @test: test context
+ * @node: node to pass to `of_node_put()`
+ *
+ * Just like of_node_put(), except the node is managed by the test case and is
+ * automatically put with of_node_put() after the test case concludes.
+ */
+void of_node_put_kunit(struct kunit *test, struct device_node *node)
+{
+       if (kunit_add_action(test, of_node_put_wrapper, node)) {
+               KUNIT_FAIL(test,
+                          "Can't allocate a kunit resource to put of_node\n");
+       }
+}
+EXPORT_SYMBOL_GPL(of_node_put_kunit);

include/kunit/of.h new file +115 -1

new file mode 100644
index 000000000000..48d4e70c9666
@@ -0,0 +1,115 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _KUNIT_OF_H
+#define _KUNIT_OF_H
+
+#include <kunit/test.h>
+
+struct device_node;
+
+#ifdef CONFIG_OF
+
+void of_node_put_kunit(struct kunit *test, struct device_node *node);
+
+#else
+
+static inline
+void of_node_put_kunit(struct kunit *test, struct device_node *node)
+{
+       kunit_skip(test, "requires CONFIG_OF");
+}
+
+#endif /* !CONFIG_OF */
+
+#if defined(CONFIG_OF) && defined(CONFIG_OF_OVERLAY) && defined(CONFIG_OF_EARLY_FLATTREE)
+
+int of_overlay_fdt_apply_kunit(struct kunit *test, void *overlay_fdt,
+                              u32 overlay_fdt_size, int *ovcs_id);
+#else
+
+static inline int
+of_overlay_fdt_apply_kunit(struct kunit *test, void *overlay_fdt,
+                          u32 overlay_fdt_size, int *ovcs_id)
+{
+       kunit_skip(test, "requires CONFIG_OF and CONFIG_OF_OVERLAY and CONFIG_OF_EARLY_FLATTREE for root node");
+       return -EINVAL;
+}
+
+#endif
+
+/**
+ * __of_overlay_apply_kunit() - Test managed of_overlay_fdt_apply() variant
+ * @test: test context
+ * @overlay_begin: start address of overlay to apply
+ * @overlay_end: end address of overlay to apply
+ *
+ * This is mostly internal API. See of_overlay_apply_kunit() for the wrapper
+ * that makes this easier to use.
+ *
+ * Similar to of_overlay_fdt_apply(), except the overlay is managed by the test
+ * case and is automatically removed with of_overlay_remove() after the test
+ * case concludes.
+ *
+ * Return: 0 on success, negative errno on failure
+ */
+static inline int __of_overlay_apply_kunit(struct kunit *test,
+                                          u8 *overlay_begin,
+                                          const u8 *overlay_end)
+{
+       int unused;
+
+       return of_overlay_fdt_apply_kunit(test, overlay_begin,
+                                         overlay_end - overlay_begin,
+                                         &unused);
+}
+
+/**
+ * of_overlay_apply_kunit() - Test managed of_overlay_fdt_apply() for built-in overlays
+ * @test: test context
+ * @overlay_name: name of overlay to apply
+ *
+ * This macro is used to apply a device tree overlay built with the
+ * cmd_dt_S_dtbo rule in scripts/Makefile.lib that has been compiled into the
+ * kernel image or KUnit test module. The overlay is automatically removed when
+ * the test is finished.
+ *
+ * Unit tests that need device tree nodes should compile an overlay file with
+ * @overlay_name\.dtbo.o in their Makefile along with their unit test and then
+ * load the overlay during their test. The @overlay_name matches the filename
+ * of the overlay without the dtbo filename extension. If CONFIG_OF_OVERLAY is
+ * not enabled, the @test will be skipped.
+ *
+ * In the Makefile
+ *
+ * .. code-block:: none
+ *
+ *     obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay_test.o kunit_overlay_test.dtbo.o
+ *
+ * In the test
+ *
+ * .. code-block:: c
+ *
+ *     static void of_overlay_kunit_of_overlay_apply(struct kunit *test)
+ *     {
+ *             struct device_node *np;
+ *
+ *             KUNIT_ASSERT_EQ(test, 0,
+ *                             of_overlay_apply_kunit(test, kunit_overlay_test));
+ *
+ *             np = of_find_node_by_name(NULL, "test-kunit");
+ *             KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+ *             of_node_put(np);
+ *     }
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+#define of_overlay_apply_kunit(test, overlay_name)             \
+({                                                             \
+       extern uint8_t __dtbo_##overlay_name##_begin[];         \
+       extern uint8_t __dtbo_##overlay_name##_end[];           \
+                                                               \
+       __of_overlay_apply_kunit((test),                        \
+                       __dtbo_##overlay_name##_begin,          \
+                       __dtbo_##overlay_name##_end);           \
+})
+
+#endif
--

https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

This looks good to me.

I was a little confused at first by some of the wrapper names: in particular that of_overlay_fdt_apply_kunit() is applying the overlay immediately, and deferring a cleanup action, but of_node_put_kunit() is not doing anything immediately, and deferring the put action. My feeling is that the ideal thing would be to have wrappers for all of the of_* functions which return a node which needs to be 'put', and have those wrappers add an of_node_put() action. You could then have of_node_put_kunit() provide a way to trigger that action early. But that seems like it'd be a lot of work and generate a lot of wrappers we otherwise wouldn't need, so this seems an okay compromise to be able to keep using the existing of_ functions. The documentation / comments help make this more clear, too.

So, no actual problems. (Assuming you don't want to put the documentation under the devicetree rather than under KUnit -- it can go either way.)

Reviewed-by David Gow <[email protected]>

Test the KUnit test managed overlay APIs. Confirm that platform devices are created and destroyed properly. This provides us confidence that the test managed APIs work correctly and can be relied upon to provide tests with fake platform devices and device nodes via overlays compiled into the kernel image.

Cc Rob Herring <[email protected]>

Cc Saravana Kannan <[email protected]>

Cc Daniel Latypov <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Reviewed-by Rob Herring (Arm) <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---
 drivers/of/.kunitconfig            |   1 +
 drivers/of/Kconfig                 |  10 +++
 drivers/of/Makefile                |   1 +
 drivers/of/kunit_overlay_test.dtso |   9 +++
 drivers/of/overlay_test.c          | 116 +++++++++++++++++++++++++++++
 5 files changed, 137 insertions(+)
 create mode 100644 drivers/of/kunit_overlay_test.dtso
 create mode 100644 drivers/of/overlay_test.c

drivers/of/.kunitconfig +1 -0

index 5a8fee11978c..4c53d2c7a275 100644
@@ -1,3 +1,4 @@
 CONFIG_KUNIT=y
 CONFIG_OF=y
 CONFIG_OF_KUNIT_TEST=y
+CONFIG_OF_OVERLAY_KUNIT_TEST=y

drivers/of/Kconfig +10 -0

index dd726c7056bf..0e2d608c3e20 100644
@@ -107,6 +107,16 @@ config OF_OVERLAY
 	  While this option is selected automatically when needed, you can
 	  enable it manually to improve device tree unit test coverage.
 
+config OF_OVERLAY_KUNIT_TEST
+	tristate "Device Tree overlay KUnit tests" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	select OF_OVERLAY
+	help
+	  This option builds KUnit unit tests for the device tree overlay code.
+
+	  If unsure, say N here, but this option is safe to enable.
+
 config OF_NUMA
 	bool
 

drivers/of/Makefile +1 -0

index 2ae909adde49..abd9c578343b 100644
@@ -21,5 +21,6 @@ endif
 
 obj-$(CONFIG_KUNIT) += of_kunit_helpers.o
 obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay_test.o kunit_overlay_test.dtbo.o
 
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/

drivers/of/kunit_overlay_test.dtso new file +9 -0

new file mode 100644
index 000000000000..85f20b4b4c16
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&{/} {
+	kunit-test {
+		compatible = "test,empty";
+	};
+};

drivers/of/overlay_test.c new file +33 -0

new file mode 100644
index 000000000000..9a8083c3a659
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for device tree overlays
+ */
+#include <linux/device/bus.h>
+#include <linux/kconfig.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <kunit/of.h>
+#include <kunit/test.h>
+
+static const char * const kunit_node_name = "kunit-test";
+static const char * const kunit_compatible = "test,empty";
+
+/* Test that of_overlay_apply_kunit() adds a node to the live tree */
+static void of_overlay_apply_kunit_apply(struct kunit *test)
+{
+	struct device_node *np;
+
+	KUNIT_ASSERT_EQ(test, 0,
+			of_overlay_apply_kunit(test, kunit_overlay_test));
+
+	np = of_find_node_by_name(NULL, kunit_node_name);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+	of_node_put(np);
+}
+
+/*
+ * Test that of_overlay_apply_kunit() creates platform devices with the
+ * expected device_node
+ */

drivers/of/overlay_test.c new file +27 -0

+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);
+
+	pdev = of_find_device_by_node(np);
+	KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pdev);
+	if (pdev)
+		put_device(&pdev->dev);
+}
+
+static int of_overlay_bus_match_compatible(struct device *dev, const void *data)
+{
+	return of_device_is_compatible(dev->of_node, data);
+}
+
+/* Test that of_overlay_apply_kunit() cleans up after the test is finished */
+static void of_overlay_apply_kunit_cleanup(struct kunit *test)
+{
+	struct kunit fake;
+	struct platform_device *pdev;
+	struct device *dev;
+	struct device_node *np;
+
+	if (!IS_ENABLED(CONFIG_OF_OVERLAY))
+		kunit_skip(test, "requires CONFIG_OF_OVERLAY");
+	if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
+		kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE for root node");
+
+	kunit_init_test(&fake, "fake test", NULL);

drivers/of/overlay_test.c new file +36 -0

+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+	put_device(&pdev->dev); /* Not derefing 'pdev' after this */
+
+	/* Remove overlay */
+	kunit_cleanup(&fake);
+
+	/* The node and device should be removed */
+	np = of_find_node_by_name(NULL, kunit_node_name);
+	KUNIT_EXPECT_PTR_EQ(test, NULL, np);
+	of_node_put(np);
+
+	dev = bus_find_device(&platform_bus_type, NULL, kunit_compatible,
+			      of_overlay_bus_match_compatible);
+	KUNIT_EXPECT_PTR_EQ(test, NULL, dev);
+	put_device(dev);
+}
+
+static struct kunit_case of_overlay_apply_kunit_test_cases[] = {
+	KUNIT_CASE(of_overlay_apply_kunit_apply),
+	KUNIT_CASE(of_overlay_apply_kunit_platform_device),
+	KUNIT_CASE(of_overlay_apply_kunit_cleanup),
+	{}
+};
+
+/*
+ * Test suite for test managed device tree overlays.
+ */
+static struct kunit_suite of_overlay_apply_kunit_suite = {
+	.name = "of_overlay_apply_kunit",
+	.test_cases = of_overlay_apply_kunit_test_cases,
+};
+
+kunit_test_suites(
+	&of_overlay_apply_kunit_suite,
+);
+MODULE_LICENSE("GPL");

Signature · 2 lines

https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

Quoted 46 lines

drivers/of/Makefile +0 -0

index 2ae909adde49..abd9c578343b 100644

drivers/of/overlay_test.c new file +38 -0

new file mode 100644
index 000000000000..9a8083c3a659
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for device tree overlays
+ */
+#include <linux/device/bus.h>
+#include <linux/kconfig.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <kunit/of.h>
+#include <kunit/test.h>
+
+static const char * const kunit_node_name = "kunit-test";
+static const char * const kunit_compatible = "test,empty";
+
+/* Test that of_overlay_apply_kunit() adds a node to the live tree */
+static void of_overlay_apply_kunit_apply(struct kunit *test)
+{
+     struct device_node *np;
+
+     KUNIT_ASSERT_EQ(test, 0,
+                     of_overlay_apply_kunit(test, kunit_overlay_test));
+
+     np = of_find_node_by_name(NULL, kunit_node_name);
+     KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+     of_node_put(np);
+}
+
+/*
+ * Test that of_overlay_apply_kunit() creates platform devices with the
+ * expected device_node
+ */
+static void of_overlay_apply_kunit_platform_device(struct kunit *test)
+{
+     struct platform_device *pdev;
+     struct device_node *np;
+

drivers/of/overlay_test.c line 43

Quoted 5 lines

drivers/of/overlay_test.c new file +5 -0

+     KUNIT_ASSERT_EQ(test, 0,
+                     of_overlay_apply_kunit(test, kunit_overlay_test));
+
+     np = of_find_node_by_name(NULL, kunit_node_name);
+     of_node_put_kunit(test, np);

Moving target, but we now have of_node_put() cleanups. Would that work here instead?

Quoted 32 lines

drivers/of/overlay_test.c new file +31 -0

+     KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);
+
+     pdev = of_find_device_by_node(np);
+     KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pdev);
+     if (pdev)
+             put_device(&pdev->dev);
+}
+
+static int of_overlay_bus_match_compatible(struct device *dev, const void *data)
+{
+     return of_device_is_compatible(dev->of_node, data);
+}
+
+/* Test that of_overlay_apply_kunit() cleans up after the test is finished */
+static void of_overlay_apply_kunit_cleanup(struct kunit *test)
+{
+     struct kunit fake;
+     struct platform_device *pdev;
+     struct device *dev;
+     struct device_node *np;
+
+     if (!IS_ENABLED(CONFIG_OF_OVERLAY))
+             kunit_skip(test, "requires CONFIG_OF_OVERLAY");
+     if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
+             kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE for root node");
+
+     kunit_init_test(&fake, "fake test", NULL);
+     KUNIT_ASSERT_EQ(test, fake.status, KUNIT_SUCCESS);
+
+     KUNIT_ASSERT_EQ(test, 0,
+                     of_overlay_apply_kunit(&fake, kunit_overlay_test));

drivers/of/overlay_test.c line 80

Quoted 6 lines

drivers/of/overlay_test.c new file +6 -0

+
+     np = of_find_node_by_name(NULL, kunit_node_name);
+     of_node_put(np); /* Not derefing 'np' after this */
+     KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);
+
+     pdev = of_find_device_by_node(np);

Don't you need to hold a ref on np until here?

Test the KUnit test managed overlay APIs. Confirm that platform devices are created and destroyed properly. This provides us confidence that the test managed APIs work correctly and can be relied upon to provide tests with fake platform devices and device nodes via overlays compiled into the kernel image.

Cc Rob Herring <[email protected]>

Cc Saravana Kannan <[email protected]>

Cc Daniel Latypov <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Reviewed-by Rob Herring (Arm) <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---

 drivers/of/.kunitconfig            |   1 +
 drivers/of/Kconfig                 |  10 +++
 drivers/of/Makefile                |   1 +
 drivers/of/kunit_overlay_test.dtso |   9 +++
 drivers/of/overlay_test.c          | 116 +++++++++++++++++++++++++++++
 5 files changed, 137 insertions(+)
 create mode 100644 drivers/of/kunit_overlay_test.dtso
 create mode 100644 drivers/of/overlay_test.c

drivers/of/.kunitconfig +1 -0

index 5a8fee11978c..4c53d2c7a275 100644
@@ -1,3 +1,4 @@
 CONFIG_KUNIT=y
 CONFIG_OF=y
 CONFIG_OF_KUNIT_TEST=y
+CONFIG_OF_OVERLAY_KUNIT_TEST=y

drivers/of/Kconfig +10 -0

index dd726c7056bf..0e2d608c3e20 100644
@@ -107,6 +107,16 @@ config OF_OVERLAY
          While this option is selected automatically when needed, you can
          enable it manually to improve device tree unit test coverage.
 
+config OF_OVERLAY_KUNIT_TEST
+       tristate "Device Tree overlay KUnit tests" if !KUNIT_ALL_TESTS
+       depends on KUNIT
+       default KUNIT_ALL_TESTS
+       select OF_OVERLAY
+       help
+         This option builds KUnit unit tests for the device tree overlay code.
+
+         If unsure, say N here, but this option is safe to enable.
+
 config OF_NUMA
        bool
 

drivers/of/Makefile +1 -0

index 2ae909adde49..abd9c578343b 100644
@@ -21,5 +21,6 @@ endif
 
 obj-$(CONFIG_KUNIT) += of_kunit_helpers.o
 obj-$(CONFIG_OF_KUNIT_TEST) += of_test.o
+obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay_test.o kunit_overlay_test.dtbo.o
 
 obj-$(CONFIG_OF_UNITTEST) += unittest-data/

drivers/of/kunit_overlay_test.dtso new file +9 -0

new file mode 100644
index 000000000000..85f20b4b4c16
@@ -0,0 +1,9 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+&{/} {
+       kunit-test {
+               compatible = "test,empty";
+       };
+};

drivers/of/overlay_test.c new file +116 -1

new file mode 100644
index 000000000000..9a8083c3a659
@@ -0,0 +1,116 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for device tree overlays
+ */
+#include <linux/device/bus.h>
+#include <linux/kconfig.h>
+#include <linux/of.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+
+#include <kunit/of.h>
+#include <kunit/test.h>
+
+static const char * const kunit_node_name = "kunit-test";
+static const char * const kunit_compatible = "test,empty";
+
+/* Test that of_overlay_apply_kunit() adds a node to the live tree */
+static void of_overlay_apply_kunit_apply(struct kunit *test)
+{
+       struct device_node *np;
+
+       KUNIT_ASSERT_EQ(test, 0,
+                       of_overlay_apply_kunit(test, kunit_overlay_test));
+
+       np = of_find_node_by_name(NULL, kunit_node_name);
+       KUNIT_EXPECT_NOT_ERR_OR_NULL(test, np);
+       of_node_put(np);
+}
+
+/*
+ * Test that of_overlay_apply_kunit() creates platform devices with the
+ * expected device_node
+ */
+static void of_overlay_apply_kunit_platform_device(struct kunit *test)
+{
+       struct platform_device *pdev;
+       struct device_node *np;
+
+       KUNIT_ASSERT_EQ(test, 0,
+                       of_overlay_apply_kunit(test, kunit_overlay_test));
+
+       np = of_find_node_by_name(NULL, kunit_node_name);
+       of_node_put_kunit(test, np);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);
+
+       pdev = of_find_device_by_node(np);
+       KUNIT_EXPECT_NOT_ERR_OR_NULL(test, pdev);
+       if (pdev)
+               put_device(&pdev->dev);
+}
+
+static int of_overlay_bus_match_compatible(struct device *dev, const void *data)
+{
+       return of_device_is_compatible(dev->of_node, data);
+}
+
+/* Test that of_overlay_apply_kunit() cleans up after the test is finished */
+static void of_overlay_apply_kunit_cleanup(struct kunit *test)
+{
+       struct kunit fake;
+       struct platform_device *pdev;
+       struct device *dev;
+       struct device_node *np;
+
+       if (!IS_ENABLED(CONFIG_OF_OVERLAY))
+               kunit_skip(test, "requires CONFIG_OF_OVERLAY");
+       if (!IS_ENABLED(CONFIG_OF_EARLY_FLATTREE))
+               kunit_skip(test, "requires CONFIG_OF_EARLY_FLATTREE for root node");
+
+       kunit_init_test(&fake, "fake test", NULL);
+       KUNIT_ASSERT_EQ(test, fake.status, KUNIT_SUCCESS);
+
+       KUNIT_ASSERT_EQ(test, 0,
+                       of_overlay_apply_kunit(&fake, kunit_overlay_test));
+
+       np = of_find_node_by_name(NULL, kunit_node_name);
+       of_node_put(np); /* Not derefing 'np' after this */
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, np);
+
+       pdev = of_find_device_by_node(np);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+       put_device(&pdev->dev); /* Not derefing 'pdev' after this */
+
+       /* Remove overlay */
+       kunit_cleanup(&fake);
+
+       /* The node and device should be removed */
+       np = of_find_node_by_name(NULL, kunit_node_name);
+       KUNIT_EXPECT_PTR_EQ(test, NULL, np);
+       of_node_put(np);
+
+       dev = bus_find_device(&platform_bus_type, NULL, kunit_compatible,
+                             of_overlay_bus_match_compatible);
+       KUNIT_EXPECT_PTR_EQ(test, NULL, dev);
+       put_device(dev);
+}
+
+static struct kunit_case of_overlay_apply_kunit_test_cases[] = {
+       KUNIT_CASE(of_overlay_apply_kunit_apply),
+       KUNIT_CASE(of_overlay_apply_kunit_platform_device),
+       KUNIT_CASE(of_overlay_apply_kunit_cleanup),
+       {}
+};
+
+/*
+ * Test suite for test managed device tree overlays.
+ */
+static struct kunit_suite of_overlay_apply_kunit_suite = {
+       .name = "of_overlay_apply_kunit",
+       .test_cases = of_overlay_apply_kunit_test_cases,
+};
+
+kunit_test_suites(
+       &of_overlay_apply_kunit_suite,
+);
+MODULE_LICENSE("GPL");
--

https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

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Quoted 15 lines

Test the KUnit test managed overlay APIs. Confirm that platform devices are created and destroyed properly. This provides us confidence that the test managed APIs work correctly and can be relied upon to provide tests with fake platform devices and device nodes via overlays compiled into the kernel image.

Cc Rob Herring <[email protected]>

Cc Saravana Kannan <[email protected]>

Cc Daniel Latypov <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Reviewed-by Rob Herring (Arm) <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

Quoted 1 line

---

This is looking good from my point of view, and passes on my test setup. One minor question (do we need both to select OF_OVERLAY and skip if it's not enabled?), but otherwise:

Introduce KUnit resource wrappers around platform_driver_register(), platform_device_alloc(), and platform_device_add() so that test authors can register platform drivers/devices from their tests and have the drivers/devices automatically be unregistered when the test is done.

This makes test setup code simpler when a platform driver or platform device is needed. Add a few test cases at the same time to make sure the APIs work as intended.

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Cc Greg Kroah-Hartman <[email protected]>

Cc "Rafael J. Wysocki" <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---
 Documentation/dev-tools/kunit/api/index.rst   |   5 +
 .../dev-tools/kunit/api/platformdevice.rst    |  10 +
 include/kunit/platform_device.h               |  20 ++
 lib/kunit/Makefile                            |   4 +-
 lib/kunit/platform-test.c                     | 223 +++++++++++++
 lib/kunit/platform.c                          | 302 ++++++++++++++++++
 6 files changed, 563 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/dev-tools/kunit/api/platformdevice.rst
 create mode 100644 include/kunit/platform_device.h
 create mode 100644 lib/kunit/platform-test.c
 create mode 100644 lib/kunit/platform.c

Introduce KUnit resource wrappers around platform_driver_register(), platform_device_alloc(), and platform_device_add() so that test authors can register platform drivers/devices from their tests and have the drivers/devices automatically be unregistered when the test is done.

This makes test setup code simpler when a platform driver or platform device is needed. Add a few test cases at the same time to make sure the APIs work as intended.

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Cc Greg Kroah-Hartman <[email protected]>

Cc "Rafael J. Wysocki" <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---

 Documentation/dev-tools/kunit/api/index.rst   |   5 +
 .../dev-tools/kunit/api/platformdevice.rst    |  10 +
 include/kunit/platform_device.h               |  20 ++
 lib/kunit/Makefile                            |   4 +-
 lib/kunit/platform-test.c                     | 223 +++++++++++++
 lib/kunit/platform.c                          | 302 ++++++++++++++++++
 6 files changed, 563 insertions(+), 1 deletion(-)
 create mode 100644 Documentation/dev-tools/kunit/api/platformdevice.rst
 create mode 100644 include/kunit/platform_device.h
 create mode 100644 lib/kunit/platform-test.c
 create mode 100644 lib/kunit/platform.c

Documentation/dev-tools/kunit/api/index.rst +5 -0

index 282befa17edf..02b26f5e8750 100644
@@ -10,6 +10,7 @@ API Reference
        resource
        functionredirection
        of
+       platformdevice
 
 
 This page documents the KUnit kernel testing API. It is divided into the

@@ -36,3 +37,7 @@ Driver KUnit API
 Documentation/dev-tools/kunit/api/of.rst
 
  - Documents the KUnit device tree (OF) API
+
+Documentation/dev-tools/kunit/api/platformdevice.rst
+
+ - Documents the KUnit platform device API

Documentation/dev-tools/kunit/api/platformdevice.rst new file +10 -0

new file mode 100644
index 000000000000..49ddd5729003
@@ -0,0 +1,10 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+===================
+Platform Device API
+===================
+
+The KUnit platform device API is used to test platform devices.
+
+.. kernel-doc:: lib/kunit/platform.c
+   :export:

include/kunit/platform_device.h new file +20 -0

new file mode 100644
index 000000000000..0fc0999d2420
@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _KUNIT_PLATFORM_DRIVER_H
+#define _KUNIT_PLATFORM_DRIVER_H
+
+struct kunit;
+struct platform_device;
+struct platform_driver;
+
+struct platform_device *
+kunit_platform_device_alloc(struct kunit *test, const char *name, int id);
+int kunit_platform_device_add(struct kunit *test, struct platform_device *pdev);
+
+int kunit_platform_device_prepare_wait_for_probe(struct kunit *test,
+                                                struct platform_device *pdev,
+                                                struct completion *x);
+
+int kunit_platform_driver_register(struct kunit *test,
+                                  struct platform_driver *drv);
+
+#endif

lib/kunit/Makefile +3 -1

index 309659a32a78..a980ae62eff6 100644
@@ -8,7 +8,8 @@ kunit-objs +=                           test.o \
                                        try-catch.o \
                                        executor.o \
                                        attributes.o \
-                                       device.o
+                                       device.o \
+                                       platform.o
 
 ifeq ($(CONFIG_KUNIT_DEBUGFS),y)
 kunit-objs +=                          debugfs.o

@@ -18,6 +19,7 @@ endif
 obj-y +=                               hooks.o
 
 obj-$(CONFIG_KUNIT_TEST) +=            kunit-test.o
+obj-$(CONFIG_KUNIT_TEST) +=            platform-test.o
 
 # string-stream-test compiles built-in only.
 ifeq ($(CONFIG_KUNIT_TEST),y)

lib/kunit/platform-test.c new file +223 -0

new file mode 100644
index 000000000000..b4fbedadc55e
@@ -0,0 +1,223 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for platform driver infrastructure.
+ */
+
+#include <linux/platform_device.h>
+
+#include <kunit/platform_device.h>
+#include <kunit/test.h>
+
+/*
+ * Test that kunit_platform_device_alloc() creates a platform device.
+ */
+static void kunit_platform_device_alloc_test(struct kunit *test)
+{
+       KUNIT_EXPECT_NOT_ERR_OR_NULL(test,
+                       kunit_platform_device_alloc(test, "kunit-platform", 1));
+}
+
+/*
+ * Test that kunit_platform_device_add() registers a platform device on the
+ * platform bus with the proper name and id.
+ */
+static void kunit_platform_device_add_test(struct kunit *test)
+{
+       struct platform_device *pdev;
+       const char *name = "kunit-platform-add";
+       const int id = -1;
+
+       pdev = kunit_platform_device_alloc(test, name, id);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+       KUNIT_EXPECT_EQ(test, 0, kunit_platform_device_add(test, pdev));
+       KUNIT_EXPECT_TRUE(test, dev_is_platform(&pdev->dev));
+       KUNIT_EXPECT_STREQ(test, pdev->name, name);
+       KUNIT_EXPECT_EQ(test, pdev->id, id);
+}
+
+/*
+ * Test that kunit_platform_device_add() called twice with the same device name
+ * and id fails the second time and properly cleans up.
+ */
+static void kunit_platform_device_add_twice_fails_test(struct kunit *test)
+{
+       struct platform_device *pdev;
+       const char *name = "kunit-platform-add-2";
+       const int id = -1;
+
+       pdev = kunit_platform_device_alloc(test, name, id);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_add(test, pdev));
+
+       pdev = kunit_platform_device_alloc(test, name, id);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+       KUNIT_EXPECT_NE(test, 0, kunit_platform_device_add(test, pdev));
+}
+
+static int kunit_platform_device_find_by_name(struct device *dev, const void *data)
+{
+       return strcmp(dev_name(dev), data) == 0;
+}
+
+/*
+ * Test that kunit_platform_device_add() cleans up by removing the platform
+ * device when the test finishes. */
+static void kunit_platform_device_add_cleans_up(struct kunit *test)
+{
+       struct platform_device *pdev;
+       const char *name = "kunit-platform-clean";
+       const int id = -1;
+       struct kunit fake;
+       struct device *dev;
+
+       kunit_init_test(&fake, "kunit_platform_device_add_fake_test", NULL);
+       KUNIT_ASSERT_EQ(test, fake.status, KUNIT_SUCCESS);
+
+       pdev = kunit_platform_device_alloc(&fake, name, id);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_add(&fake, pdev));
+       dev = bus_find_device(&platform_bus_type, NULL, name,
+                             kunit_platform_device_find_by_name);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+       put_device(dev);
+
+       /* Remove pdev */
+       kunit_cleanup(&fake);
+
+       /*
+        * Failing to migrate the kunit_resource would lead to an extra
+        * put_device() call on the platform device. The best we can do here is
+        * make sure the device no longer exists on the bus, but if something
+        * is wrong we'll see a refcount underflow here. We can't test for a
+        * refcount underflow because the kref matches the lifetime of the
+        * device which should already be freed and could be used by something
+        * else.
+        */
+       dev = bus_find_device(&platform_bus_type, NULL, name,
+                             kunit_platform_device_find_by_name);
+       KUNIT_EXPECT_PTR_EQ(test, NULL, dev);
+       put_device(dev);
+}
+
+/*
+ * Test suite for struct platform_device kunit APIs
+ */
+static struct kunit_case kunit_platform_device_test_cases[] = {
+       KUNIT_CASE(kunit_platform_device_alloc_test),
+       KUNIT_CASE(kunit_platform_device_add_test),
+       KUNIT_CASE(kunit_platform_device_add_twice_fails_test),
+       KUNIT_CASE(kunit_platform_device_add_cleans_up),
+       {}
+};
+
+static struct kunit_suite kunit_platform_device_suite = {
+       .name = "kunit_platform_device",
+       .test_cases = kunit_platform_device_test_cases,
+};
+
+struct kunit_platform_driver_test_context {
+       struct platform_driver pdrv;
+       const char *data;
+};
+
+static const char * const test_data = "test data";
+
+static inline struct kunit_platform_driver_test_context *
+to_test_context(struct platform_device *pdev)
+{
+       return container_of(to_platform_driver(pdev->dev.driver),
+                           struct kunit_platform_driver_test_context,
+                           pdrv);
+}
+
+static int kunit_platform_driver_probe(struct platform_device *pdev)
+{
+       struct kunit_platform_driver_test_context *ctx;
+
+       ctx = to_test_context(pdev);
+       ctx->data = test_data;
+
+       return 0;
+}
+
+/* Test that kunit_platform_driver_register() registers a driver that probes. */
+static void kunit_platform_driver_register_test(struct kunit *test)
+{
+       struct platform_device *pdev;
+       struct kunit_platform_driver_test_context *ctx;
+       DECLARE_COMPLETION_ONSTACK(comp);
+       const char *name = "kunit-platform-register";
+
+       ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+       pdev = kunit_platform_device_alloc(test, name, -1);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_add(test, pdev));
+
+       ctx->pdrv.probe = kunit_platform_driver_probe;
+       ctx->pdrv.driver.name = name;
+       ctx->pdrv.driver.owner = THIS_MODULE;
+
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_prepare_wait_for_probe(test, pdev, &comp));
+
+       KUNIT_EXPECT_EQ(test, 0, kunit_platform_driver_register(test, &ctx->pdrv));
+       KUNIT_EXPECT_NE(test, 0, wait_for_completion_timeout(&comp, 3 * HZ));
+       KUNIT_EXPECT_STREQ(test, ctx->data, test_data);
+}
+
+/*
+ * Test that kunit_platform_device_prepare_wait_for_probe() completes the completion
+ * when the device is already probed.
+ */
+static void kunit_platform_device_prepare_wait_for_probe_completes_when_already_probed(struct kunit *test)
+{
+       struct platform_device *pdev;
+       struct kunit_platform_driver_test_context *ctx;
+       DECLARE_COMPLETION_ONSTACK(comp);
+       const char *name = "kunit-platform-wait";
+
+       ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+       pdev = kunit_platform_device_alloc(test, name, -1);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_add(test, pdev));
+
+       ctx->pdrv.probe = kunit_platform_driver_probe;
+       ctx->pdrv.driver.name = name;
+       ctx->pdrv.driver.owner = THIS_MODULE;
+
+       /* Make sure driver has actually probed */
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_prepare_wait_for_probe(test, pdev, &comp));
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_driver_register(test, &ctx->pdrv));
+       KUNIT_ASSERT_NE(test, 0, wait_for_completion_timeout(&comp, 3 * HZ));
+
+       reinit_completion(&comp);
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_prepare_wait_for_probe(test, pdev, &comp));
+
+       KUNIT_EXPECT_NE(test, 0, wait_for_completion_timeout(&comp, HZ));
+}
+
+static struct kunit_case kunit_platform_driver_test_cases[] = {
+       KUNIT_CASE(kunit_platform_driver_register_test),
+       KUNIT_CASE(kunit_platform_device_prepare_wait_for_probe_completes_when_already_probed),
+       {}
+};
+
+/*
+ * Test suite for struct platform_driver kunit APIs
+ */
+static struct kunit_suite kunit_platform_driver_suite = {
+       .name = "kunit_platform_driver",
+       .test_cases = kunit_platform_driver_test_cases,
+};
+
+kunit_test_suites(
+       &kunit_platform_device_suite,
+       &kunit_platform_driver_suite,
+);
+
+MODULE_LICENSE("GPL");

lib/kunit/platform.c new file +302 -1

new file mode 100644
index 000000000000..ba1b0006dc45
@@ -0,0 +1,302 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Test managed platform driver
+ */
+
+#include <linux/completion.h>
+#include <linux/device/bus.h>
+#include <linux/device/driver.h>
+#include <linux/platform_device.h>
+
+#include <kunit/platform_device.h>
+#include <kunit/resource.h>
+
+struct kunit_platform_device_alloc_params {
+       const char *name;
+       int id;
+};
+
+static int kunit_platform_device_alloc_init(struct kunit_resource *res, void *context)
+{
+       struct kunit_platform_device_alloc_params *params = context;
+       struct platform_device *pdev;
+
+       pdev = platform_device_alloc(params->name, params->id);
+       if (!pdev)
+               return -ENOMEM;
+
+       res->data = pdev;
+
+       return 0;
+}
+
+static void kunit_platform_device_alloc_exit(struct kunit_resource *res)
+{
+       struct platform_device *pdev = res->data;
+
+       platform_device_put(pdev);
+}
+
+/**
+ * kunit_platform_device_alloc() - Allocate a KUnit test managed platform device
+ * @test: test context
+ * @name: device name of platform device to alloc
+ * @id: identifier of platform device to alloc.
+ *
+ * Allocate a test managed platform device. The device is put when the test completes.
+ *
+ * Return: Allocated platform device on success, NULL on failure.
+ */
+struct platform_device *
+kunit_platform_device_alloc(struct kunit *test, const char *name, int id)
+{
+       struct kunit_platform_device_alloc_params params = {
+               .name = name,
+               .id = id,
+       };
+
+       return kunit_alloc_resource(test,
+                                   kunit_platform_device_alloc_init,
+                                   kunit_platform_device_alloc_exit,
+                                   GFP_KERNEL, &params);
+}
+EXPORT_SYMBOL_GPL(kunit_platform_device_alloc);
+
+static void kunit_platform_device_add_exit(struct kunit_resource *res)
+{
+       struct platform_device *pdev = res->data;
+
+       platform_device_unregister(pdev);
+}
+
+static bool
+kunit_platform_device_alloc_match(struct kunit *test,
+                                 struct kunit_resource *res, void *match_data)
+{
+       struct platform_device *pdev = match_data;
+
+       return res->data == pdev && res->free != kunit_platform_device_alloc_exit;
+}
+
+KUNIT_DEFINE_ACTION_WRAPPER(platform_device_unregister_wrapper,
+                           platform_device_unregister, struct platform_device *);
+/**
+ * kunit_platform_device_add() - Register a KUnit test managed platform device
+ * @test: test context
+ * @pdev: platform device to add
+ *
+ * Register a test managed platform device. The device is unregistered when the
+ * test completes.
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kunit_platform_device_add(struct kunit *test, struct platform_device *pdev)
+{
+       struct kunit_resource *res;
+       int ret;
+
+       ret = platform_device_add(pdev);
+       if (ret)
+               return ret;
+
+       res = kunit_find_resource(test, kunit_platform_device_alloc_match, pdev);
+       if (res) {
+               /*
+                * Transfer the reference count of the platform device if it
+                * was allocated with kunit_platform_device_alloc(). In this
+                * case, calling platform_device_put() when the test exits from
+                * kunit_platform_device_alloc_exit() would lead to reference
+                * count underflow because platform_device_unregister_wrapper()
+                * calls platform_device_unregister() which also calls
+                * platform_device_put().
+                *
+                * Usually callers transfer the refcount initialized in
+                * platform_device_alloc() to platform_device_add() by calling
+                * platform_device_unregister() when platform_device_add()
+                * succeeds or platform_device_put() when it fails. KUnit has to
+                * keep this straight by redirecting the free routine for the
+                * resource to the right function. Luckily this only has to
+                * account for the success scenario.
+                */
+               res->free = kunit_platform_device_add_exit;
+               kunit_put_resource(res);
+       } else {
+               ret = kunit_add_action_or_reset(test, platform_device_unregister_wrapper, pdev);
+               if (ret)
+                       return ret;
+       }
+
+       return 0;
+}
+EXPORT_SYMBOL_GPL(kunit_platform_device_add);
+
+struct kunit_platform_device_probe_nb {
+       struct completion *x;
+       struct device *dev;
+       struct notifier_block nb;
+};
+
+static int kunit_platform_device_probe_notify(struct notifier_block *nb,
+                                             unsigned long event, void *data)
+{
+       struct kunit_platform_device_probe_nb *knb;
+       struct device *dev = data;
+
+       knb = container_of(nb, struct kunit_platform_device_probe_nb, nb);
+       if (event != BUS_NOTIFY_BOUND_DRIVER || knb->dev != dev)
+               return NOTIFY_DONE;
+
+       complete(knb->x);
+
+       return NOTIFY_OK;
+}
+
+static void kunit_platform_device_probe_nb_remove(void *nb)
+{
+       bus_unregister_notifier(&platform_bus_type, nb);
+}
+
+/**
+ * kunit_platform_device_prepare_wait_for_probe() - Prepare a completion
+ * variable to wait for a platform device to probe
+ * @test: test context
+ * @pdev: platform device to prepare to wait for probe of
+ * @x: completion variable completed when @dev has probed
+ *
+ * Prepare a completion variable @x to wait for @pdev to probe. Waiting on the
+ * completion forces a preemption, allowing the platform driver to probe.
+ *
+ * Example
+ *
+ * .. code-block:: c
+ *
+ *     static int kunit_platform_driver_probe(struct platform_device *pdev)
+ *     {
+ *             return 0;
+ *     }
+ *
+ *     static void kunit_platform_driver_test(struct kunit *test)
+ *     {
+ *             struct platform_device *pdev;
+ *             struct platform_driver *pdrv;
+ *             DECLARE_COMPLETION_ONSTACK(comp);
+ *
+ *             pdev = kunit_platform_device_alloc(test, "kunit-platform", -1);
+ *             KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+ *             KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_add(test, pdev));
+ *
+ *             pdrv = kunit_kzalloc(test, sizeof(*pdrv), GFP_KERNEL);
+ *             KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdrv);
+ *
+ *             pdrv->probe = kunit_platform_driver_probe;
+ *             pdrv->driver.name = "kunit-platform";
+ *             pdrv->driver.owner = THIS_MODULE;
+ *
+ *             KUNIT_ASSERT_EQ(test, 0, kunit_platform_device_prepare_wait_for_probe(test, pdev, &comp));
+ *             KUNIT_ASSERT_EQ(test, 0, kunit_platform_driver_register(test, pdrv));
+ *
+ *             KUNIT_EXPECT_NE(test, 0, wait_for_completion_timeout(&comp, 3 * HZ));
+ *     }
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kunit_platform_device_prepare_wait_for_probe(struct kunit *test,
+                                                struct platform_device *pdev,
+                                                struct completion *x)
+{
+       struct device *dev = &pdev->dev;
+       struct kunit_platform_device_probe_nb *knb;
+       bool bound;
+
+       knb = kunit_kzalloc(test, sizeof(*knb), GFP_KERNEL);
+       if (!knb)
+               return -ENOMEM;
+
+       knb->nb.notifier_call = kunit_platform_device_probe_notify;
+       knb->dev = dev;
+       knb->x = x;
+
+       device_lock(dev);
+       bound = device_is_bound(dev);
+       if (bound) {
+               device_unlock(dev);
+               complete(x);
+               kunit_kfree(test, knb);
+               return 0;
+       }
+
+       bus_register_notifier(&platform_bus_type, &knb->nb);
+       device_unlock(&pdev->dev);
+
+       return kunit_add_action_or_reset(test, kunit_platform_device_probe_nb_remove, &knb->nb);
+}
+EXPORT_SYMBOL_GPL(kunit_platform_device_prepare_wait_for_probe);
+
+KUNIT_DEFINE_ACTION_WRAPPER(platform_driver_unregister_wrapper,
+                           platform_driver_unregister, struct platform_driver *);
+/**
+ * kunit_platform_driver_register() - Register a KUnit test managed platform driver
+ * @test: test context
+ * @drv: platform driver to register
+ *
+ * Register a test managed platform driver. This allows callers to embed the
+ * @drv in a container structure and use container_of() in the probe function
+ * to pass information to KUnit tests.
+ *
+ * Example
+ *
+ * .. code-block:: c
+ *
+ *     struct kunit_test_context {
+ *             struct platform_driver pdrv;
+ *             const char *data;
+ *     };
+ *
+ *     static inline struct kunit_test_context *
+ *     to_test_context(struct platform_device *pdev)
+ *     {
+ *             return container_of(to_platform_driver(pdev->dev.driver),
+ *                                 struct kunit_test_context,
+ *                                 pdrv);
+ *     }
+ *
+ *     static int kunit_platform_driver_probe(struct platform_device *pdev)
+ *     {
+ *             struct kunit_test_context *ctx;
+ *
+ *             ctx = to_test_context(pdev);
+ *             ctx->data = "test data";
+ *
+ *             return 0;
+ *     }
+ *
+ *     static void kunit_platform_driver_test(struct kunit *test)
+ *     {
+ *             struct kunit_test_context *ctx;
+ *
+ *             ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+ *             KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+ *
+ *             ctx->pdrv.probe = kunit_platform_driver_probe;
+ *             ctx->pdrv.driver.name = "kunit-platform";
+ *             ctx->pdrv.driver.owner = THIS_MODULE;
+ *
+ *             KUNIT_EXPECT_EQ(test, 0, kunit_platform_driver_register(test, &ctx->pdrv));
+ *             <... wait for driver to probe ...>
+ *             KUNIT_EXPECT_STREQ(test, ctx->data, "test data");
+ *     }
+ *
+ * Return: 0 on success, negative errno on failure.
+ */
+int kunit_platform_driver_register(struct kunit *test,
+                                  struct platform_driver *drv)
+{
+       int ret;
+
+       ret = platform_driver_register(drv);
+       if (ret)
+               return ret;
+
+       return kunit_add_action_or_reset(test, platform_driver_unregister_wrapper, drv);
+}
+EXPORT_SYMBOL_GPL(kunit_platform_driver_register);
--

https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

Describe a binding for a device that consumes a single clk in DT. This will initially be used by a KUnit test to clk_get() the clk registered by of_fixed_clk_setup() and test that it is setup properly.

Cc Rob Herring <[email protected]>

Cc Krzysztof Kozlowski <[email protected]>

Cc Conor Dooley <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---
 .../test/test,single-clk-consumer.yaml        | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml

Describe a binding for a device that consumes a single clk in DT. This will initially be used by a KUnit test to clk_get() the clk registered by of_fixed_clk_setup() and test that it is setup properly.

Cc Rob Herring <[email protected]>

Cc Krzysztof Kozlowski <[email protected]>

Cc Conor Dooley <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---
 .../test/test,single-clk-consumer.yaml        | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml

Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml new file +7 -0

new file mode 100644
index 000000000000..8c384c48707d
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/test/test,single-clk-consumer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Test consumer of a single clock

Quoted 29 lines

Describe a binding for a device that consumes a single clk in DT. This will initially be used by a KUnit test to clk_get() the clk registered by of_fixed_clk_setup() and test that it is setup properly.

Cc Rob Herring <[email protected]>

Cc Krzysztof Kozlowski <[email protected]>

Cc Conor Dooley <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---
 .../test/test,single-clk-consumer.yaml        | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml

Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml new file +7 -0

new file mode 100644
index 000000000000..8c384c48707d
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/test/test,single-clk-consumer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Test consumer of a single clock

Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml line 17

Quoted 10 lines

Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml new file +10 -0

+
+maintainers:
+  - Stephen Boyd <[email protected]>
+
+description:
+  A consumer of a single clock used in tests.
+
+properties:
+  compatible:
+    const: test,single-clk-consumer

I don't know if there's much value in defining bindings for tests. We could alternatively make 'test,' opt out of everything. There's already some support in dtschema for this with 'foo,'.

I need something for the DT unittest as well.

Quoting Rob Herring (2024-06-04 06:05:26)

Quoted 45 lines · Stephen Boyd

Quoted 29 lines

Describe a binding for a device that consumes a single clk in DT. This will initially be used by a KUnit test to clk_get() the clk registered by of_fixed_clk_setup() and test that it is setup properly.

Cc Rob Herring <[email protected]>

Cc Krzysztof Kozlowski <[email protected]>

Cc Conor Dooley <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---
 .../test/test,single-clk-consumer.yaml        | 34 +++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml

Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml new file +7 -0

new file mode 100644
index 000000000000..8c384c48707d
@@ -0,0 +1,34 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/test/test,single-clk-consumer.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Test consumer of a single clock

Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml line 17

Quoted 10 lines

Documentation/devicetree/bindings/test/test,single-clk-consumer.yaml new file +10 -0

+
+maintainers:
+  - Stephen Boyd <[email protected]>
+
+description:
+  A consumer of a single clock used in tests.
+
+properties:
+  compatible:
+    const: test,single-clk-consumer

I don't know if there's much value in defining bindings for tests. We could alternatively make 'test,' opt out of everything. There's already some support in dtschema for this with 'foo,'.

Quoted 2 lines

I need something for the DT unittest as well.

Ok. So I should drop this patch and the other one that adds a binding for the fake clock provider?

And replace it with something that makes
the test vendor prefix opt out of all checking? How is that done? Some patch to dtschema directly?

Quoted 4 lines

And replace it with something that makes
the test vendor prefix opt out of all checking? How is that done? Some patch to dtschema directly?

Yes, but I just added it for you.

Yes, but I just added it for you.

Test that clks registered with 'struct clk_parent_data' work as intended and can find their parents.

Cc Christian Marangi <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---

 drivers/clk/Kconfig                         |   1 +
 drivers/clk/Makefile                        |   3 +-
 drivers/clk/clk_parent_data_test.h          |  10 +
 drivers/clk/clk_test.c                      | 451 +++++++++++++++++++-
 drivers/clk/kunit_clk_parent_data_test.dtso |  28 ++
 5 files changed, 491 insertions(+), 2 deletions(-)
 create mode 100644 drivers/clk/clk_parent_data_test.h
 create mode 100644 drivers/clk/kunit_clk_parent_data_test.dtso

drivers/clk/Kconfig +1 -0

index f649f2a0279c..c33fdf9fdcd6 100644
@@ -508,6 +508,7 @@ config CLK_KUNIT_TEST
        tristate "Basic Clock Framework Kunit Tests" if !KUNIT_ALL_TESTS
        depends on KUNIT
        default KUNIT_ALL_TESTS
+       select OF_OVERLAY if OF
        help
          Kunit tests for the common clock framework.
 

drivers/clk/Makefile +0 -0

index 7b57e3d22cee..ed4e1a0e6943 100644

drivers/clk/Makefile +0 -0

 obj-$(CONFIG_COMMON_CLK)       += clk-divider.o
 obj-$(CONFIG_COMMON_CLK)       += clk-fixed-factor.o
 obj-$(CONFIG_COMMON_CLK)       += clk-fixed-rate.o

drivers/clk/clk_parent_data_test.h new file +10 -0

new file mode 100644
index 000000000000..eedd53ae910d
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef _CLK_PARENT_DATA_TEST_H
+#define _CLK_PARENT_DATA_TEST_H
+
+#define CLK_PARENT_DATA_1MHZ_NAME      "1mhz_fixed_legacy"
+#define CLK_PARENT_DATA_PARENT1                "parent_fwname"
+#define CLK_PARENT_DATA_PARENT2                "50"
+#define CLK_PARENT_DATA_50MHZ_NAME     "50_clk"
+
+#endif

drivers/clk/clk_test.c +101 -0

index 39e2b5ff4f51..bdf3c4bb2243 100644
@@ -4,12 +4,19 @@
  */
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
 
 /* Needed for clk_hw_get_clk() */
 #include "clk.h"
 
+#include <kunit/clk.h>
+#include <kunit/of.h>
+#include <kunit/platform_device.h>
 #include <kunit/test.h>
 
+#include "clk_parent_data_test.h"
+
 static const struct clk_ops empty_clk_ops = { };
 
 #define DUMMY_CLOCK_INIT_RATE  (42 * 1000 * 1000)

@@ -2659,6 +2666,446 @@ static struct kunit_suite clk_mux_no_reparent_test_suite = {
        .test_cases = clk_mux_no_reparent_test_cases,
 };
 
+struct clk_register_clk_parent_data_test_case {
+       const char *desc;
+       struct clk_parent_data pdata;
+};
+
+static void
+clk_register_clk_parent_data_test_case_to_desc(
+               const struct clk_register_clk_parent_data_test_case *t, char *desc)
+{
+       strcpy(desc, t->desc);
+}
+
+static const struct clk_register_clk_parent_data_test_case
+clk_register_clk_parent_data_of_cases[] = {
+       {
+               /*
+                * Test that a clk registered with a struct device_node can
+                * find a parent based on struct clk_parent_data::index.
+                */
+               .desc = "clk_parent_data_of_index_test",
+               .pdata.index = 0,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device_node can
+                * find a parent based on struct clk_parent_data::fwname.
+                */
+               .desc = "clk_parent_data_of_fwname_test",
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT1,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device_node can
+                * find a parent based on struct clk_parent_data::name.
+                */
+               .desc = "clk_parent_data_of_name_test",
+               /* The index must be negative to indicate firmware not used */
+               .pdata.index = -1,
+               .pdata.name = CLK_PARENT_DATA_1MHZ_NAME,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device_node can
+                * find a parent based on struct
+                * clk_parent_data::{fw_name,name}.
+                */
+               .desc = "clk_parent_data_of_fwname_name_test",
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT1,
+               .pdata.name = "not_matching",
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device_node can
+                * find a parent based on struct clk_parent_data::{index,name}.
+                * Index takes priority.
+                */
+               .desc = "clk_parent_data_of_index_name_priority_test",
+               .pdata.index = 0,
+               .pdata.name = "not_matching",
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device_node can
+                * find a parent based on struct
+                * clk_parent_data::{index,fwname,name}. The fw_name takes
+                * priority over index and name.
+                */
+               .desc = "clk_parent_data_of_index_fwname_name_priority_test",
+               .pdata.index = 1,
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT1,
+               .pdata.name = "not_matching",
+       },
+};
+
+KUNIT_ARRAY_PARAM(clk_register_clk_parent_data_of_test, clk_register_clk_parent_data_of_cases,
+                 clk_register_clk_parent_data_test_case_to_desc)
+
+/**
+ * struct clk_register_clk_parent_data_of_ctx - Context for clk_parent_data OF tests
+ * @np: device node of clk under test
+ * @hw: clk_hw for clk under test
+ */
+struct clk_register_clk_parent_data_of_ctx {
+       struct device_node *np;
+       struct clk_hw hw;
+};
+
+static int clk_register_clk_parent_data_of_test_init(struct kunit *test)
+{
+       struct clk_register_clk_parent_data_of_ctx *ctx;
+
+       KUNIT_ASSERT_EQ(test, 0,
+                       of_overlay_apply_kunit(test, kunit_clk_parent_data_test));
+

drivers/clk/clk_test.c +339 -1

+}
+
+/*
+ * Test that a clk registered with a struct device_node can find a parent based on
+ * struct clk_parent_data when the hw member isn't set.
+ */
+static void clk_register_clk_parent_data_of_test(struct kunit *test)
+{
+       struct clk_register_clk_parent_data_of_ctx *ctx = test->priv;
+       struct clk_hw *parent_hw;
+       const struct clk_register_clk_parent_data_test_case *test_param;
+       struct clk_init_data init = { };
+       struct clk *expected_parent, *actual_parent;
+
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->np);
+
+       expected_parent = of_clk_get_kunit(test, ctx->np, 0);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_parent);
+
+       test_param = test->param_value;
+       init.parent_data = &test_param->pdata;
+       init.num_parents = 1;
+       init.name = "parent_data_of_test_clk";
+       init.ops = &clk_dummy_single_parent_ops;
+       ctx->hw.init = &init;
+       KUNIT_ASSERT_EQ(test, 0, of_clk_hw_register_kunit(test, ctx->np, &ctx->hw));
+
+       parent_hw = clk_hw_get_parent(&ctx->hw);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent_hw);
+
+       actual_parent = clk_hw_get_clk_kunit(test, parent_hw, __func__);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, actual_parent);
+
+       KUNIT_EXPECT_TRUE(test, clk_is_match(expected_parent, actual_parent));
+}
+
+static struct kunit_case clk_register_clk_parent_data_of_test_cases[] = {
+       KUNIT_CASE_PARAM(clk_register_clk_parent_data_of_test,
+                        clk_register_clk_parent_data_of_test_gen_params),
+       {}
+};
+
+/*
+ * Test suite for registering clks with struct clk_parent_data and a struct
+ * device_node.
+ */
+static struct kunit_suite clk_register_clk_parent_data_of_suite = {
+       .name = "clk_register_clk_parent_data_of",
+       .init = clk_register_clk_parent_data_of_test_init,
+       .test_cases = clk_register_clk_parent_data_of_test_cases,
+};
+
+/**
+ * struct clk_register_clk_parent_data_device_ctx - Context for clk_parent_data device tests
+ * @dev: device of clk under test
+ * @hw: clk_hw for clk under test
+ * @pdrv: driver to attach to find @dev
+ */
+struct clk_register_clk_parent_data_device_ctx {
+       struct device *dev;
+       struct clk_hw hw;
+       struct platform_driver pdrv;
+};
+
+static inline struct clk_register_clk_parent_data_device_ctx *
+clk_register_clk_parent_data_driver_to_test_context(struct platform_device *pdev)
+{
+       return container_of(to_platform_driver(pdev->dev.driver),
+                           struct clk_register_clk_parent_data_device_ctx, pdrv);
+}
+
+static int clk_register_clk_parent_data_device_probe(struct platform_device *pdev)
+{
+       struct clk_register_clk_parent_data_device_ctx *ctx;
+
+       ctx = clk_register_clk_parent_data_driver_to_test_context(pdev);
+       ctx->dev = &pdev->dev;
+
+       return 0;
+}
+
+static void clk_register_clk_parent_data_device_driver(struct kunit *test)
+{
+       struct clk_register_clk_parent_data_device_ctx *ctx = test->priv;
+       static const struct of_device_id match_table[] = {
+               { .compatible = "test,clk-parent-data" },
+               { }
+       };
+
+       ctx->pdrv.probe = clk_register_clk_parent_data_device_probe;
+       ctx->pdrv.driver.of_match_table = match_table;
+       ctx->pdrv.driver.name = __func__;
+       ctx->pdrv.driver.owner = THIS_MODULE;
+
+       KUNIT_ASSERT_EQ(test, 0, kunit_platform_driver_register(test, &ctx->pdrv));
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx->dev);
+}
+
+static const struct clk_register_clk_parent_data_test_case
+clk_register_clk_parent_data_device_cases[] = {
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::index.
+                */
+               .desc = "clk_parent_data_device_index_test",
+               .pdata.index = 1,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::fwname.
+                */
+               .desc = "clk_parent_data_device_fwname_test",
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT2,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::name.
+                */
+               .desc = "clk_parent_data_device_name_test",
+               /* The index must be negative to indicate firmware not used */
+               .pdata.index = -1,
+               .pdata.name = CLK_PARENT_DATA_50MHZ_NAME,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::{fw_name,name}.
+                */
+               .desc = "clk_parent_data_device_fwname_name_test",
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT2,
+               .pdata.name = "not_matching",
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::{index,name}. Index
+                * takes priority.
+                */
+               .desc = "clk_parent_data_device_index_name_priority_test",
+               .pdata.index = 1,
+               .pdata.name = "not_matching",
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::{index,fwname,name}.
+                * The fw_name takes priority over index and name.
+                */
+               .desc = "clk_parent_data_device_index_fwname_name_priority_test",
+               .pdata.index = 0,
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT2,
+               .pdata.name = "not_matching",
+       },
+};
+
+KUNIT_ARRAY_PARAM(clk_register_clk_parent_data_device_test,
+                 clk_register_clk_parent_data_device_cases,
+                 clk_register_clk_parent_data_test_case_to_desc)
+
+/*
+ * Test that a clk registered with a struct device can find a parent based on
+ * struct clk_parent_data when the hw member isn't set.
+ */
+static void clk_register_clk_parent_data_device_test(struct kunit *test)
+{
+       struct clk_register_clk_parent_data_device_ctx *ctx;
+       const struct clk_register_clk_parent_data_test_case *test_param;
+       struct clk_hw *parent_hw;
+       struct clk_init_data init = { };
+       struct clk *expected_parent, *actual_parent;
+
+       ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+       test->priv = ctx;
+
+       clk_register_clk_parent_data_device_driver(test);
+
+       expected_parent = clk_get_kunit(test, ctx->dev, "50");
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, expected_parent);
+
+       test_param = test->param_value;
+       init.parent_data = &test_param->pdata;
+       init.num_parents = 1;
+       init.name = "parent_data_device_test_clk";
+       init.ops = &clk_dummy_single_parent_ops;
+       ctx->hw.init = &init;
+       KUNIT_ASSERT_EQ(test, 0, clk_hw_register_kunit(test, ctx->dev, &ctx->hw));
+
+       parent_hw = clk_hw_get_parent(&ctx->hw);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent_hw);
+
+       actual_parent = clk_hw_get_clk_kunit(test, parent_hw, __func__);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, actual_parent);
+
+       KUNIT_EXPECT_TRUE(test, clk_is_match(expected_parent, actual_parent));
+}
+
+static const struct clk_register_clk_parent_data_test_case
+clk_register_clk_parent_data_device_hw_cases[] = {
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::hw.
+                */
+               .desc = "clk_parent_data_device_hw_index_test",
+               /* The index must be negative to indicate firmware not used */
+               .pdata.index = -1,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::hw when
+                * struct clk_parent_data::fw_name is set.
+                */
+               .desc = "clk_parent_data_device_hw_fwname_test",
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT2,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::hw when struct
+                * clk_parent_data::name is set.
+                */
+               .desc = "clk_parent_data_device_hw_name_test",
+               /* The index must be negative to indicate firmware not used */
+               .pdata.index = -1,
+               .pdata.name = CLK_PARENT_DATA_50MHZ_NAME,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::hw when struct
+                * clk_parent_data::{fw_name,name} are set.
+                */
+               .desc = "clk_parent_data_device_hw_fwname_name_test",
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT2,
+               .pdata.name = "not_matching",
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::hw when struct
+                * clk_parent_data::index is set. The hw pointer takes
+                * priority.
+                */
+               .desc = "clk_parent_data_device_hw_index_priority_test",
+               .pdata.index = 0,
+       },
+       {
+               /*
+                * Test that a clk registered with a struct device can find a
+                * parent based on struct clk_parent_data::hw when
+                * struct clk_parent_data::{index,fwname,name} are set.
+                * The hw pointer takes priority over everything else.
+                */
+               .desc = "clk_parent_data_device_hw_index_fwname_name_priority_test",
+               .pdata.index = 0,
+               .pdata.fw_name = CLK_PARENT_DATA_PARENT2,
+               .pdata.name = "not_matching",
+       },
+};
+
+KUNIT_ARRAY_PARAM(clk_register_clk_parent_data_device_hw_test,
+                 clk_register_clk_parent_data_device_hw_cases,
+                 clk_register_clk_parent_data_test_case_to_desc)
+
+/*
+ * Test that a clk registered with a struct device can find a
+ * parent based on struct clk_parent_data::hw.
+ */
+static void clk_register_clk_parent_data_device_hw_test(struct kunit *test)
+{
+       struct clk_register_clk_parent_data_device_ctx *ctx;
+       const struct clk_register_clk_parent_data_test_case *test_param;
+       struct clk_dummy_context *parent;
+       struct clk_hw *parent_hw;
+       struct clk_parent_data pdata = { };
+       struct clk_init_data init = { };
+
+       ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+       test->priv = ctx;
+
+       clk_register_clk_parent_data_device_driver(test);
+
+       parent = kunit_kzalloc(test, sizeof(*parent), GFP_KERNEL);
+       KUNIT_ASSERT_NOT_ERR_OR_NULL(test, parent);
+
+       parent_hw = &parent->hw;
+       parent_hw->init = CLK_HW_INIT_NO_PARENT("parenlookst-clk",
+                                               &clk_dummy_rate_ops, 0);
+
+       KUNIT_ASSERT_EQ(test, 0, clk_hw_register_kunit(test, ctx->dev, parent_hw));
+
+       test_param = test->param_value;
+       memcpy(&pdata, &test_param->pdata, sizeof(pdata));
+       pdata.hw = parent_hw;
+       init.parent_data = &pdata;
+       init.num_parents = 1;
+       init.ops = &clk_dummy_single_parent_ops;
+       init.name = "parent_data_device_hw_test_clk";
+       ctx->hw.init = &init;
+       KUNIT_ASSERT_EQ(test, 0, clk_hw_register_kunit(test, ctx->dev, &ctx->hw));
+
+       KUNIT_EXPECT_PTR_EQ(test, parent_hw, clk_hw_get_parent(&ctx->hw));
+}
+
+static struct kunit_case clk_register_clk_parent_data_device_test_cases[] = {
+       KUNIT_CASE_PARAM(clk_register_clk_parent_data_device_test,
+                        clk_register_clk_parent_data_device_test_gen_params),
+       KUNIT_CASE_PARAM(clk_register_clk_parent_data_device_hw_test,
+                        clk_register_clk_parent_data_device_hw_test_gen_params),
+       {}
+};
+
+static int clk_register_clk_parent_data_device_init(struct kunit *test)
+{
+       KUNIT_ASSERT_EQ(test, 0,
+                       of_overlay_apply_kunit(test, kunit_clk_parent_data_test));
+
+       return 0;
+}
+
+/*
+ * Test suite for registering clks with struct clk_parent_data and a struct
+ * device.
+ */
+static struct kunit_suite clk_register_clk_parent_data_device_suite = {
+       .name = "clk_register_clk_parent_data_device",
+       .init = clk_register_clk_parent_data_device_init,
+       .test_cases = clk_register_clk_parent_data_device_test_cases,
+};
+
 kunit_test_suites(
        &clk_leaf_mux_set_rate_parent_test_suite,
        &clk_test_suite,

@@ -2671,7 +3118,9 @@ kunit_test_suites(
        &clk_range_test_suite,
        &clk_range_maximize_test_suite,
        &clk_range_minimize_test_suite,
+       &clk_register_clk_parent_data_of_suite,
+       &clk_register_clk_parent_data_device_suite,
        &clk_single_parent_mux_test_suite,
-       &clk_uncached_test_suite
+       &clk_uncached_test_suite,
 );
 MODULE_LICENSE("GPL v2");

drivers/clk/kunit_clk_parent_data_test.dtso new file +28 -1

new file mode 100644
index 000000000000..7d3ed9a5a2e8
@@ -0,0 +1,28 @@
+// SPDX-License-Identifier: GPL-2.0
+/dts-v1/;
+/plugin/;
+
+#include "clk_parent_data_test.h"
+
+&{/} {
+       fixed_50: kunit-clock-50MHz {
+               compatible = "fixed-clock";
+               #clock-cells = <0>;
+               clock-frequency = <50000000>;
+               clock-output-names = CLK_PARENT_DATA_50MHZ_NAME;
+       };
+
+       fixed_parent: kunit-clock-1MHz {
+               compatible = "fixed-clock";
+               #clock-cells = <0>;
+               clock-frequency = <1000000>;
+               clock-output-names = CLK_PARENT_DATA_1MHZ_NAME;
+       };
+
+       kunit-clock-controller {
+               compatible = "test,clk-parent-data";
+               clocks = <&fixed_parent>, <&fixed_50>;
+               clock-names = CLK_PARENT_DATA_PARENT1, CLK_PARENT_DATA_PARENT2;
+               #clock-cells = <1>;
+       };
+};
--

https://git.kernel.org/pub/scm/linux/kernel/git/clk/linux.git/
https://git.kernel.org/pub/scm/linux/kernel/git/sboyd/spmi.git

Quoted 10 lines

Test that clks registered with 'struct clk_parent_data' work as intended and can find their parents.

Cc Christian Marangi <[email protected]>

Cc Brendan Higgins <[email protected]>

Cc David Gow <[email protected]>

Cc Rae Moar <[email protected]>

Signed-off-by Stephen Boyd <[email protected]>

---

This seems good to me overall, but will break if we can't compile the dtbo.o file. Maybe these need to live behind a #if IS_ENABLED(CONFIG_OF) or equivalent.

Also, there's a cast to kunit_action_t* which needs to use a wrapper.

Otherwise,

Reviewed-by David Gow <[email protected]>

Cheers,
-- David

Quoted 21 lines

 drivers/clk/Kconfig                         |   1 +
 drivers/clk/Makefile                        |   3 +-
 drivers/clk/clk_parent_data_test.h          |  10 +
 drivers/clk/clk_test.c                      | 451 +++++++++++++++++++-
 drivers/clk/kunit_clk_parent_data_test.dtso |  28 ++
 5 files changed, 491 insertions(+), 2 deletions(-)
 create mode 100644 drivers/clk/clk_parent_data_test.h
 create mode 100644 drivers/clk/kunit_clk_parent_data_test.dtso

drivers/clk/Kconfig +1 -0

index f649f2a0279c..c33fdf9fdcd6 100644
@@ -508,6 +508,7 @@ config CLK_KUNIT_TEST
        tristate "Basic Clock Framework Kunit Tests" if !KUNIT_ALL_TESTS
        depends on KUNIT
        default KUNIT_ALL_TESTS
+       select OF_OVERLAY if OF
        help
          Kunit tests for the common clock framework.
 

drivers/clk/Makefile line 6

Quoted 11 lines

drivers/clk/Makefile +2 -1

index 7b57e3d22cee..ed4e1a0e6943 100644
@@ -2,7 +2,8 @@
 # common clock types
 obj-$(CONFIG_HAVE_CLK)         += clk-devres.o clk-bulk.o clkdev.o
 obj-$(CONFIG_COMMON_CLK)       += clk.o
-obj-$(CONFIG_CLK_KUNIT_TEST)   += clk_test.o
+obj-$(CONFIG_CLK_KUNIT_TEST)   += clk_test.o \
+                                  kunit_clk_parent_data_test.dtbo.o

This breaks if CONFIG_OF isn't enabled, as there's no rule to compile it:
make[5]: *** No rule to make target 'drivers/clk/kunit_clk_parent_data_test.dtbo.o', needed by 'drivers/clk/modules.order'. Stop.

Quoted 13 lines

drivers/clk/clk_test.c +2 -0

index 39e2b5ff4f51..bdf3c4bb2243 100644
@@ -4,12 +4,19 @@
  */
 #include <linux/clk.h>
 #include <linux/clk-provider.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
 
 /* Needed for clk_hw_get_clk() */
 #include "clk.h"

Quoted 24 lines

drivers/clk/clk_test.c +24 -0

+
+/**
+ * struct clk_register_clk_parent_data_of_ctx - Context for clk_parent_data OF tests
+ * @np: device node of clk under test
+ * @hw: clk_hw for clk under test
+ */
+struct clk_register_clk_parent_data_of_ctx {
+       struct device_node *np;
+       struct clk_hw hw;
+};
+
+static int clk_register_clk_parent_data_of_test_init(struct kunit *test)
+{
+       struct clk_register_clk_parent_data_of_ctx *ctx;
+
+       KUNIT_ASSERT_EQ(test, 0,
+                       of_overlay_apply_kunit(test, kunit_clk_parent_data_test));
+
+       ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+       if (!ctx)
+               return -ENOMEM;
+       test->priv = ctx;
+
+       ctx->np = of_find_compatible_node(NULL, NULL, "test,clk-parent-data");

drivers/clk/clk_test.c static struct kunit_suite clk_mux_no_reparent_test_suite = { · line 2772

Quoted 4 lines

drivers/clk/clk_test.c +4 -0

+       if (!ctx->np)
+               return -ENODEV;
+
+       return kunit_add_action_or_reset(test, (kunit_action_t *)&of_node_put, ctx->np);

We should use an action wrapper here (KUNIT_DEFINE_ACTION_WRAPPER()), as casting function pointers to kunit_action_t* breaks control-flow integrity.

Quoting David Gow (2024-06-13 00:56:08)

Quoted 4 lines

We should use an action wrapper here (KUNIT_DEFINE_ACTION_WRAPPER()), as casting function pointers to kunit_action_t* breaks control-flow integrity.

Got it, thanks. Maybe there should be an of_node_put_kunit_exit() helper that does that and can be used anywhere.