Device Tree (OF) API¶

The KUnit device tree API is used to test device tree (of_*) dependent code.

int __of_overlay_apply_kunit(struct kunit *test, u8 *overlay_begin, const u8 *overlay_end)¶: Test managed of_overlay_fdt_apply() variant

Parameters

struct kunit *test: test context
u8 *overlay_begin: start address of overlay to apply
const u8 *overlay_end: end address of overlay to apply

Description

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

of_overlay_apply_kunit¶

of_overlay_apply_kunit (test, overlay_name)

Test managed of_overlay_fdt_apply() for built-in overlays

Parameters

test: test context
overlay_name: name of overlay to apply

Description

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

obj-$(CONFIG_OF_OVERLAY_KUNIT_TEST) += overlay_test.o kunit_overlay_test.dtbo.o

In the test

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.

void of_root_kunit_skip(struct kunit *test)¶: Skip test if the root node isn’t populated

Parameters

struct kunit *test: test to skip if the root node isn’t populated

int of_overlay_fdt_apply_kunit(struct kunit *test, void *overlay_fdt, u32 overlay_fdt_size, int *ovcs_id)¶: Test managed of_overlay_fdt_apply()

Parameters

struct kunit *test: test context
void *overlay_fdt: device tree overlay to apply
u32 overlay_fdt_size: size in bytes of overlay_fdt
int *ovcs_id: identifier of overlay, used to remove the overlay

Description

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

void of_node_put_kunit(struct kunit *test, struct device_node *node)¶: Test managed of_node_put()

Parameters

struct kunit *test: test context
struct device_node *node: node to pass to of_node_put()

Description

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.