[PATCH 0/2] power: sequencing: add kunit test cases

[PATCH 0/2] power: sequencing: add kunit test cases

[Bartosz Golaszewski]

Add a set of kunit test cases for the power sequencing subsystem. Also
fix an issue I noticed when writing the tests.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
Bartosz Golaszewski (2):
      power: sequencing: don't call .post_enable() if pwrseq_unit_enable() failed
      power: sequencing: add kunit test cases

 drivers/power/sequencing/Kconfig        |   10 +
 drivers/power/sequencing/Makefile       |    1 +
 drivers/power/sequencing/core.c         |    2 +
 drivers/power/sequencing/pwrseq-kunit.c | 1497 +++++++++++++++++++++++++++++++
 4 files changed, 1510 insertions(+)
---
base-commit: cee9395acd8043be0644b25c34bfa86623f2b935
change-id: 20260629-pwrseq-kunit-367029f9b446

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>

[PATCH 1/2] power: sequencing: don't call .post_enable() if pwrseq_unit_enable() failed

[Bartosz Golaszewski]

If the call to pwrseq_unit_enable() failed in pwrseq_enable(), bail out
instead of calling target->post_enable() which assumes the target was
successfully enabled.

Fixes: 249ebf3f65f8 ("power: sequencing: implement the pwrseq core")
Cc: stable@vger.kernel.org
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/power/sequencing/core.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/power/sequencing/core.c b/drivers/power/sequencing/core.c
index 721e888b658d1f254513e126bb72f2d0487a8383..76c39600f690d9f19a21f4a89512ee24942e3b14 100644
--- a/drivers/power/sequencing/core.c
+++ b/drivers/power/sequencing/core.c
@@ -912,6 +912,8 @@ int pwrseq_enable(struct pwrseq_desc *desc)
 		if (!ret)
 			desc->powered_on = true;
 	}
+	if (ret)
+		return ret;
 
 	if (target->post_enable) {
 		ret = target->post_enable(pwrseq);

-- 
2.47.3

[PATCH 2/2] power: sequencing: add kunit test cases

[Bartosz Golaszewski]

Add a set of kunit test-cases for the power sequencing subsystem. Verify
several use-cases such as detecting circural dependencies, tracking of
the enable-count, shared dependencies, swnode lookup, missing target on
matching provider, etc.

Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
---
 drivers/power/sequencing/Kconfig        |   10 +
 drivers/power/sequencing/Makefile       |    1 +
 drivers/power/sequencing/pwrseq-kunit.c | 1497 +++++++++++++++++++++++++++++++
 3 files changed, 1508 insertions(+)

diff --git a/drivers/power/sequencing/Kconfig b/drivers/power/sequencing/Kconfig
index 1c5f5820f5b76479b380df79971ca5e245e62c6b..a09f18b41feafd97833dffe82e103288ffb6ce1b 100644
--- a/drivers/power/sequencing/Kconfig
+++ b/drivers/power/sequencing/Kconfig
@@ -46,4 +46,14 @@ config POWER_SEQUENCING_PCIE_M2
 	  connectors. This driver handles the power sequencing for the M.2
 	  connectors exposing multiple interfaces like PCIe, SATA, UART, etc...
 
+config POWER_SEQUENCING_KUNIT
+	tristate "Build power sequencing KUnit test cases"
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Say Y here to build the module containing KUnit test cases for the
+	  power sequencing subsystem.
+
+	  If unsure, say N.
+
 endif
diff --git a/drivers/power/sequencing/Makefile b/drivers/power/sequencing/Makefile
index 0911d461829897c5018e26dbe475b28f6fb6914c..cde06a5115d0c57b02b1a7d66cc641b691c5f5e3 100644
--- a/drivers/power/sequencing/Makefile
+++ b/drivers/power/sequencing/Makefile
@@ -6,3 +6,4 @@ pwrseq-core-y				:= core.o
 obj-$(CONFIG_POWER_SEQUENCING_QCOM_WCN)	+= pwrseq-qcom-wcn.o
 obj-$(CONFIG_POWER_SEQUENCING_TH1520_GPU) += pwrseq-thead-gpu.o
 obj-$(CONFIG_POWER_SEQUENCING_PCIE_M2)	+= pwrseq-pcie-m2.o
+obj-$(CONFIG_POWER_SEQUENCING_KUNIT)	+= pwrseq-kunit.o
diff --git a/drivers/power/sequencing/pwrseq-kunit.c b/drivers/power/sequencing/pwrseq-kunit.c
new file mode 100644
index 0000000000000000000000000000000000000000..c2899f3b16e6450eab7178e58d75e9ddc005d5e5
--- /dev/null
+++ b/drivers/power/sequencing/pwrseq-kunit.c
@@ -0,0 +1,1497 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (C) 2026 Qualcomm Technologies, Inc. and/or its subsidiaries
+ */
+
+#include <linux/err.h>
+#include <linux/fwnode.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+#include <linux/pwrseq/consumer.h>
+#include <linux/pwrseq/provider.h>
+
+#include <kunit/fwnode.h>
+#include <kunit/platform_device.h>
+#include <kunit/resource.h>
+#include <kunit/test.h>
+
+#define PWRSEQ_TEST_PARENT			"pwrseq-test-parent"
+#define PWRSEQ_TEST_CONSUMER			"pwrseq-test-consumer"
+
+#define PWRSEQ_SWNODE_TEST_PROVIDER		"pwrseq-swnode-test-provider"
+#define PWRSEQ_SWNODE_TEST_PROVIDER_2		"pwrseq-swnode-test-provider-2"
+#define PWRSEQ_PROBE_ORDER_TEST_CONSUMER	"pwrseq-probe-order-test-consumer"
+#define PWRSEQ_PROBE_DEFER_TEST_CONSUMER	"pwrseq-probe-defer-test-consumer"
+
+static const struct software_node pwrseq_test_provider_swnode = {
+	.name = "pwrseq-test-provider",
+};
+
+KUNIT_DEFINE_ACTION_WRAPPER(pwrseq_device_unregister_wrapper,
+			    pwrseq_device_unregister,
+			    struct pwrseq_device *);
+
+static struct pwrseq_device *
+kunit_pwrseq_device_register(struct kunit *test,
+			     const struct pwrseq_config *config)
+{
+	struct pwrseq_device *pwrseq;
+	int ret;
+
+	pwrseq = pwrseq_device_register(config);
+	if (IS_ERR(pwrseq))
+		return pwrseq;
+
+	ret = kunit_add_action_or_reset(test, pwrseq_device_unregister_wrapper,
+					pwrseq);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return pwrseq;
+}
+
+KUNIT_DEFINE_ACTION_WRAPPER(pwrseq_put_wrapper, pwrseq_put,
+			    struct pwrseq_desc *);
+
+static struct pwrseq_desc *
+kunit_pwrseq_get(struct kunit *test, struct device *dev, const char *target)
+{
+	struct pwrseq_desc *desc;
+	int ret;
+
+	desc = pwrseq_get(dev, target);
+	if (IS_ERR(desc))
+		return desc;
+
+	ret = kunit_add_action_or_reset(test, pwrseq_put_wrapper, desc);
+	if (ret)
+		return ERR_PTR(ret);
+
+	return desc;
+}
+
+struct pwrseq_test_ctx {
+	const char *consumer_name;
+	int enable_count_a;
+	int enable_count_b;
+	int disable_count_a;
+	int disable_count_b;
+	int enable_calls_a;
+	int post_enable_calls;
+	bool enable_error_a;
+	bool enable_error_b;
+	bool post_enable_error;
+};
+
+static int pwrseq_test_no_match(struct pwrseq_device *pwrseq,
+				struct device *dev)
+{
+	return PWRSEQ_NO_MATCH;
+}
+
+static int pwrseq_test_match_by_name(struct pwrseq_device *pwrseq,
+				     struct device *dev)
+{
+	struct pwrseq_test_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	return strcmp(dev_name(dev), ctx->consumer_name) == 0 ?
+					PWRSEQ_MATCH_OK : PWRSEQ_NO_MATCH;
+}
+
+static int pwrseq_test_match_always(struct pwrseq_device *pwrseq,
+				    struct device *dev)
+{
+	return PWRSEQ_MATCH_OK;
+}
+
+static int pwrseq_test_enable_a(struct pwrseq_device *pwrseq)
+{
+	struct pwrseq_test_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	ctx->enable_calls_a++;
+
+	if (ctx->enable_error_a)
+		return -EIO;
+
+	ctx->enable_count_a++;
+
+	return 0;
+}
+
+static int pwrseq_test_disable_a(struct pwrseq_device *pwrseq)
+{
+	struct pwrseq_test_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	ctx->disable_count_a++;
+
+	return 0;
+}
+
+static int pwrseq_test_enable_b(struct pwrseq_device *pwrseq)
+{
+	struct pwrseq_test_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	if (ctx->enable_error_b)
+		return -EIO;
+
+	ctx->enable_count_b++;
+
+	return 0;
+}
+
+static int pwrseq_test_disable_b(struct pwrseq_device *pwrseq)
+{
+	struct pwrseq_test_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	ctx->disable_count_b++;
+
+	return 0;
+}
+
+static int pwrseq_test_post_enable(struct pwrseq_device *pwrseq)
+{
+	struct pwrseq_test_ctx *ctx = pwrseq_device_get_drvdata(pwrseq);
+
+	ctx->post_enable_calls++;
+
+	return ctx->post_enable_error ? -EIO : 0;
+}
+
+static int pwrseq_test_parent_probe(struct platform_device *pdev)
+{
+	return 0;
+}
+
+static struct platform_driver pwrseq_test_parent_driver = {
+	.probe = pwrseq_test_parent_probe,
+	.driver = {
+		.name = PWRSEQ_TEST_PARENT,
+	},
+};
+
+static int pwrseq_test_parent_init(struct kunit *test)
+{
+	static const struct platform_device_info pdevinfo = {
+		.name = PWRSEQ_TEST_PARENT,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	struct platform_device *pdev;
+	bool bound;
+	int ret;
+
+	ret = kunit_platform_driver_register(test, &pwrseq_test_parent_driver);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	wait_for_device_probe();
+	scoped_guard(device, &pdev->dev)
+		bound = device_is_bound(&pdev->dev);
+
+	KUNIT_ASSERT_TRUE(test, bound);
+
+	test->priv = pdev;
+
+	return 0;
+}
+
+/*
+ * Test that registering a power sequencer whose unit dependency graph
+ * contains a two-node cycle (A -> B -> A) is rejected with -EINVAL.
+ */
+static void pwrseq_circular_deps(struct kunit *test)
+{
+	const struct pwrseq_unit_data *unit_a_deps[2] = { };
+	const struct pwrseq_unit_data *unit_b_deps[2] = { };
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct pwrseq_unit_data unit_a, unit_b;
+	struct pwrseq_target_data target;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+
+	unit_a = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.deps = unit_a_deps,
+	};
+
+	unit_b = (struct pwrseq_unit_data){
+		.name = "unit-b",
+		.deps = unit_b_deps,
+	};
+
+	unit_a_deps[0] = &unit_b;
+	unit_b_deps[0] = &unit_a;
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit_a,
+	};
+
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.match = pwrseq_test_no_match,
+		.targets = targets,
+	};
+
+	kunit_warning_suppress(test) {
+		pwrseq = kunit_pwrseq_device_register(test, &config);
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+	}
+
+	KUNIT_EXPECT_TRUE(test, IS_ERR(pwrseq));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(pwrseq), -EINVAL);
+}
+
+/*
+ * Test that a longer chain cycle (A -> B -> C -> D -> A) is also rejected
+ * with -EINVAL.
+ */
+static void pwrseq_circular_deps_chain(struct kunit *test)
+{
+	struct pwrseq_unit_data unit_a, unit_b, unit_c, unit_d;
+	const struct pwrseq_unit_data *unit_a_deps[2] = { };
+	const struct pwrseq_unit_data *unit_b_deps[2] = { };
+	const struct pwrseq_unit_data *unit_c_deps[2] = { };
+	const struct pwrseq_unit_data *unit_d_deps[2] = { };
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct pwrseq_target_data target;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+
+	unit_a = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.deps = unit_a_deps,
+	};
+	unit_b = (struct pwrseq_unit_data){
+		.name = "unit-b",
+		.deps = unit_b_deps,
+	};
+	unit_c = (struct pwrseq_unit_data){
+		.name = "unit-c",
+		.deps = unit_c_deps,
+	};
+	unit_d = (struct pwrseq_unit_data){
+		.name = "unit-d",
+		.deps = unit_d_deps,
+	};
+
+	unit_a_deps[0] = &unit_b;
+	unit_b_deps[0] = &unit_c;
+	unit_c_deps[0] = &unit_d;
+	unit_d_deps[0] = &unit_a;
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit_a,
+	};
+
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.match = pwrseq_test_no_match,
+		.targets = targets,
+	};
+
+	kunit_warning_suppress(test) {
+		pwrseq = kunit_pwrseq_device_register(test, &config);
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+	}
+
+	KUNIT_EXPECT_TRUE(test, IS_ERR(pwrseq));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(pwrseq), -EINVAL);
+}
+
+/*
+ * Test that a valid acyclic dependency graph (A -> B) registers successfully.
+ */
+static void pwrseq_register_valid(struct kunit *test)
+{
+	const struct pwrseq_unit_data *unit_a_deps[2] = { };
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct pwrseq_unit_data unit_a, unit_b;
+	struct pwrseq_target_data target;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+
+	unit_b = (struct pwrseq_unit_data){
+		.name = "unit-b",
+	};
+
+	unit_a_deps[0] = &unit_b;
+	unit_a = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.deps = unit_a_deps,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit_a,
+	};
+
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.match = pwrseq_test_no_match,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+}
+
+/*
+ * Test that registration is rejected with -EINVAL when .parent, .match or
+ * .targets is missing, or when .targets is a non-NULL but empty array.
+ */
+static void pwrseq_register_invalid_args(struct kunit *test)
+{
+	const struct pwrseq_target_data *empty_targets[1] = { };
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct pwrseq_target_data target;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+
+	unit = (struct pwrseq_unit_data){ .name = "unit-a" };
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit,
+	};
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.match = pwrseq_test_no_match,
+		.targets = targets,
+	};
+
+	config.parent = NULL;
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_EXPECT_TRUE(test, IS_ERR(pwrseq));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(pwrseq), -EINVAL);
+	config.parent = &pdev->dev;
+
+	config.match = NULL;
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_EXPECT_TRUE(test, IS_ERR(pwrseq));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(pwrseq), -EINVAL);
+	config.match = pwrseq_test_no_match;
+
+	config.targets = NULL;
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_EXPECT_TRUE(test, IS_ERR(pwrseq));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(pwrseq), -EINVAL);
+
+	config.targets = empty_targets;
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_EXPECT_TRUE(test, IS_ERR(pwrseq));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(pwrseq), -EINVAL);
+}
+
+/*
+ * Test that a target without a unit is rejected with -EINVAL.
+ */
+static void pwrseq_register_target_without_unit(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct pwrseq_target_data target;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = NULL,
+	};
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.match = pwrseq_test_no_match,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_EXPECT_TRUE(test, IS_ERR(pwrseq));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(pwrseq), -EINVAL);
+}
+
+/*
+ * Test that enabling and disabling a single-unit target increments and
+ * decrements enable_count correctly and fires the enable/disable callbacks
+ * exactly once.
+ */
+static void pwrseq_enable_disable(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_test_ctx *ctx;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+	struct pwrseq_desc *desc;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	unit = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.enable = pwrseq_test_enable_a,
+		.disable = pwrseq_test_disable_a,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit,
+	};
+
+	targets[0] = &target;
+
+	ctx->consumer_name = PWRSEQ_TEST_CONSUMER;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_by_name,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	desc = kunit_pwrseq_get(test, &pdev->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc);
+
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 0);
+
+	ret = pwrseq_disable(desc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 1);
+}
+
+/*
+ * Test that two consumers sharing a common dependency unit cause it to be
+ * enabled only once and disabled only once, while enable_count tracks each
+ * consumer correctly.
+ */
+static void pwrseq_shared_deps(struct kunit *test)
+{
+	const struct pwrseq_unit_data *unit_a_deps[2] = { };
+	const struct pwrseq_unit_data *unit_b_deps[2] = { };
+	const struct pwrseq_target_data *targets[3] = { };
+	struct pwrseq_unit_data dep_unit, unit_a, unit_b;
+	struct pwrseq_target_data target_a, target_b;
+	struct platform_device *parent = test->priv;
+	struct platform_device *pdev_a, *pdev_b;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_desc *desc_a, *desc_b;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+	struct pwrseq_test_ctx *ctx;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	dep_unit = (struct pwrseq_unit_data){
+		.name = "dep",
+		.enable = pwrseq_test_enable_a,
+		.disable = pwrseq_test_disable_a,
+	};
+
+	unit_a_deps[0] = &dep_unit;
+	unit_a = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.deps = unit_a_deps,
+		.enable = pwrseq_test_enable_b,
+		.disable = pwrseq_test_disable_b,
+	};
+
+	unit_b_deps[0] = &dep_unit;
+	unit_b = (struct pwrseq_unit_data){
+		.name = "unit-b",
+		.deps = unit_b_deps,
+	};
+
+	target_a = (struct pwrseq_target_data){
+		.name = "target-a",
+		.unit = &unit_a,
+	};
+	target_b = (struct pwrseq_target_data){
+		.name = "target-b",
+		.unit = &unit_b,
+	};
+
+	targets[0] = &target_a;
+	targets[1] = &target_b;
+
+	ctx->consumer_name = PWRSEQ_TEST_CONSUMER "-a";
+
+	config = (struct pwrseq_config){
+		.parent = &parent->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_by_name,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER "-a",
+		.id = PLATFORM_DEVID_NONE,
+	};
+	pdev_a = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev_a);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER "-b",
+		.id = PLATFORM_DEVID_NONE,
+	};
+	pdev_b = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev_b);
+
+	/*
+	 * match_by_name() only matches one consumer name at a time, so
+	 * reconfigure ctx->consumer_name between the two pwrseq_get() calls
+	 * below to acquire descriptors for both consumer-a and consumer-b.
+	 */
+	desc_a = kunit_pwrseq_get(test, &pdev_a->dev, "target-a");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc_a);
+
+	ctx->consumer_name = PWRSEQ_TEST_CONSUMER "-b";
+	desc_b = kunit_pwrseq_get(test, &pdev_b->dev, "target-b");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc_b);
+
+	ret = pwrseq_enable(desc_a);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_b, 1);
+
+	ret = pwrseq_enable(desc_b);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+
+	ret = pwrseq_disable(desc_a);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 0);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_b, 1);
+
+	ret = pwrseq_disable(desc_b);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 1);
+}
+
+/*
+ * Test that calling pwrseq_enable() twice on the same descriptor has no
+ * effect.
+ */
+static void pwrseq_enable_idempotent(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_config config;
+	struct pwrseq_test_ctx *ctx;
+	struct pwrseq_desc *desc;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	unit = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.enable = pwrseq_test_enable_a,
+		.disable = pwrseq_test_disable_a,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit,
+	};
+
+	targets[0] = &target;
+
+	ctx->consumer_name = PWRSEQ_TEST_CONSUMER;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_by_name,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	desc = kunit_pwrseq_get(test, &pdev->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc);
+
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+
+	/* Second power_on on same descriptor must be a no-op. */
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+
+	ret = pwrseq_disable(desc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 1);
+}
+
+/*
+ * Test that when a dependency unit's enable() callback fails, the error
+ * propagates to the caller, the top unit's enable callback is never reached,
+ * and target->post_enable() is never invoked.
+ */
+static void pwrseq_enable_enable_error(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	const struct pwrseq_unit_data *top_deps[2] = { };
+	struct pwrseq_unit_data dep_unit, top_unit;
+	struct platform_device *pdev = test->priv;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+	struct pwrseq_test_ctx *ctx;
+	struct pwrseq_desc *desc;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	dep_unit = (struct pwrseq_unit_data){
+		.name = "dep",
+		.enable = pwrseq_test_enable_a,
+	};
+
+	top_deps[0] = &dep_unit;
+	top_unit = (struct pwrseq_unit_data){
+		.name = "top",
+		.deps = top_deps,
+		.enable = pwrseq_test_enable_b,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &top_unit,
+		.post_enable = pwrseq_test_post_enable,
+	};
+
+	targets[0] = &target;
+
+	ctx->consumer_name = PWRSEQ_TEST_CONSUMER;
+	ctx->enable_error_a = true;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_by_name,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	desc = kunit_pwrseq_get(test, &pdev->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc);
+
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, -EIO);
+	/*
+	 * Dependency's enable() was attempted but failed, so it never
+	 * incremented.
+	 */
+	KUNIT_EXPECT_EQ(test, ctx->enable_calls_a, 1);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 0);
+	/* Target unit's enable() was never reached. */
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_b, 0);
+	/* Target's .post_enable() must not run on an unpowered sequencer. */
+	KUNIT_EXPECT_EQ(test, ctx->post_enable_calls, 0);
+}
+
+/*
+ * Test that when the top unit's own enable() callback fails after its
+ * dependency's enable() already succeeded, the dependency is rolled back.
+ */
+static void pwrseq_enable_rollback_on_top_failure(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	const struct pwrseq_unit_data *top_deps[2] = { };
+	struct pwrseq_unit_data dep_unit, top_unit;
+	struct platform_device *pdev = test->priv;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+	struct pwrseq_test_ctx *ctx;
+	struct pwrseq_desc *desc;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	dep_unit = (struct pwrseq_unit_data){
+		.name = "dep",
+		.enable = pwrseq_test_enable_a,
+		.disable = pwrseq_test_disable_a,
+	};
+
+	top_deps[0] = &dep_unit;
+	top_unit = (struct pwrseq_unit_data){
+		.name = "top",
+		.deps = top_deps,
+		.enable = pwrseq_test_enable_b,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &top_unit,
+	};
+
+	targets[0] = &target;
+
+	ctx->consumer_name = PWRSEQ_TEST_CONSUMER;
+	ctx->enable_error_b = true;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_by_name,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	desc = kunit_pwrseq_get(test, &pdev->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc);
+
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, -EIO);
+	/*
+	 * Dependency was enabled, then rolled back once top's own enable
+	 * failed.
+	 */
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 1);
+	/*
+	 * Target unit's own enable never incremented since it returned an
+	 * error.
+	 */
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_b, 0);
+}
+
+/*
+ * Test target->post_enable() on both the success and failure paths: it must
+ * run exactly once per pwrseq_enable() call that actually powers the target
+ * unit on, and a failing post_enable() must roll the unit back and clear
+ * powered_on so a subsequent pwrseq_enable() is called again.
+ */
+static void pwrseq_enable_post_enable(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+	struct pwrseq_test_ctx *ctx;
+	struct pwrseq_desc *desc;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	unit = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.enable = pwrseq_test_enable_a,
+		.disable = pwrseq_test_disable_a,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit,
+		.post_enable = pwrseq_test_post_enable,
+	};
+
+	targets[0] = &target;
+
+	ctx->consumer_name = PWRSEQ_TEST_CONSUMER;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_by_name,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	desc = kunit_pwrseq_get(test, &pdev->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc);
+
+	/* Success path: post_enable() runs once and reports success. */
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->post_enable_calls, 1);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 1);
+
+	ret = pwrseq_disable(desc);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	/* Failure path: post_enable() fails, unit is rolled back. */
+	ctx->post_enable_error = true;
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, -EIO);
+	KUNIT_EXPECT_EQ(test, ctx->post_enable_calls, 2);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 2);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 2);
+
+	/* powered_on must have been cleared. */
+	ret = pwrseq_enable(desc);
+	KUNIT_EXPECT_EQ(test, ret, -EIO);
+	KUNIT_EXPECT_EQ(test, ctx->enable_count_a, 3);
+}
+
+/*
+ * Test that pwrseq_get() returns -ENOENT when the matched provider does not
+ * have the requested target name.
+ */
+static void pwrseq_get_target_not_found(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+	struct pwrseq_desc *desc;
+
+	unit = (struct pwrseq_unit_data){
+		.name = "unit-a",
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "real-target",
+		.unit = &unit,
+	};
+
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.match = pwrseq_test_match_always,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	desc = kunit_pwrseq_get(test, &pdev->dev, "nonexistent-target");
+	KUNIT_EXPECT_TRUE(test, IS_ERR(desc));
+	KUNIT_EXPECT_EQ(test, PTR_ERR(desc), -ENOENT);
+}
+
+/*
+ * Test that pwrseq_put() on a descriptor that is still powered on disables
+ * it as part of tear-down, instead of leaking the power-on state.
+ */
+static void pwrseq_put_disables_powered_desc(struct kunit *test)
+{
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device *pdev = test->priv;
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_test_ctx *ctx;
+	struct pwrseq_config config;
+	struct pwrseq_desc *desc;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	unit = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.enable = pwrseq_test_enable_a,
+		.disable = pwrseq_test_disable_a,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit,
+	};
+
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_always,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	pdev = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+	desc = kunit_pwrseq_get(test, &pdev->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc);
+
+	ret = pwrseq_enable(desc);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 0);
+
+	/*
+	 * Run the deferred pwrseq_put() action now instead of at test
+	 * teardown, so its effect can be asserted below.
+	 */
+	kunit_release_action(test, pwrseq_put_wrapper, desc);
+	KUNIT_EXPECT_EQ(test, ctx->disable_count_a, 1);
+}
+
+/*
+ * Test that pwrseq_device_unregister() on a target with an active user
+ * triggers "REMOVING POWER SEQUENCER WITH ACTIVE USERS", and that both
+ * pwrseq_enable() and pwrseq_disable() start returning -ENODEV for
+ * previously acquired descriptors afterwards.
+ */
+static void pwrseq_unregister_with_active_user(struct kunit *test)
+{
+	struct platform_device *pdev = test->priv, *cons_a, *cons_b;
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device_info pdevinfo;
+	struct pwrseq_desc *desc_a, *desc_b;
+	struct pwrseq_target_data target;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_test_ctx *ctx;
+	struct pwrseq_config config;
+	bool bound;
+	int ret;
+
+	ctx = kunit_kzalloc(test, sizeof(*ctx), GFP_KERNEL);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, ctx);
+
+	unit = (struct pwrseq_unit_data){
+		.name = "unit-a",
+		.enable = pwrseq_test_enable_a,
+		.disable = pwrseq_test_disable_a,
+	};
+
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit,
+	};
+
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = ctx,
+		.match = pwrseq_test_match_always,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = 0,
+	};
+	cons_a = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons_a);
+
+	wait_for_device_probe();
+	scoped_guard(device, &cons_a->dev)
+		bound = device_is_bound(&cons_a->dev);
+
+	KUNIT_ASSERT_FALSE(test, bound);
+
+	pdevinfo.id = 1;
+	cons_b = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons_b);
+
+	wait_for_device_probe();
+	scoped_guard(device, &cons_b->dev)
+		bound = device_is_bound(&cons_b->dev);
+
+	KUNIT_ASSERT_FALSE(test, bound);
+
+	desc_a = kunit_pwrseq_get(test, &cons_a->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc_a);
+	desc_b = kunit_pwrseq_get(test, &cons_b->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc_b);
+
+	ret = pwrseq_enable(desc_a);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	kunit_warning_suppress(test) {
+		kunit_release_action(test, pwrseq_device_unregister_wrapper, pwrseq);
+		KUNIT_EXPECT_SUPPRESSED_WARNING_COUNT(test, 1);
+	}
+
+	ret = pwrseq_enable(desc_b);
+	KUNIT_EXPECT_EQ(test, ret, -ENODEV);
+
+	ret = pwrseq_disable(desc_a);
+	KUNIT_EXPECT_EQ(test, ret, -ENODEV);
+}
+
+/*
+ * Test that pwrseq_to_device() returns the pwrseq provider's own device,
+ * and NULL for a NULL descriptor.
+ */
+static void pwrseq_to_device_test(struct kunit *test)
+{
+	struct platform_device *parent = test->priv, *cons;
+	const struct pwrseq_target_data *targets[2] = { };
+	struct platform_device_info pdevinfo;
+	struct pwrseq_target_data target;
+	struct pwrseq_unit_data unit;
+	struct pwrseq_device *pwrseq;
+	struct pwrseq_config config;
+	struct pwrseq_desc *desc;
+	struct device *dev;
+
+	unit = (struct pwrseq_unit_data){ .name = "unit-a" };
+	target = (struct pwrseq_target_data){
+		.name = "test-target",
+		.unit = &unit,
+	};
+	targets[0] = &target;
+
+	config = (struct pwrseq_config){
+		.parent = &parent->dev,
+		.match = pwrseq_test_match_always,
+		.targets = targets,
+	};
+
+	pwrseq = kunit_pwrseq_device_register(test, &config);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pwrseq);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+	};
+
+	cons = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons);
+
+	desc = kunit_pwrseq_get(test, &cons->dev, "test-target");
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc);
+
+	dev = pwrseq_to_device(desc);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, dev);
+	KUNIT_EXPECT_PTR_EQ(test, dev->parent, &parent->dev);
+	KUNIT_EXPECT_TRUE(test, device_is_registered(dev));
+
+	KUNIT_EXPECT_PTR_EQ(test, pwrseq_to_device(NULL), NULL);
+}
+
+static struct kunit_case pwrseq_tests[] = {
+	KUNIT_CASE(pwrseq_circular_deps),
+	KUNIT_CASE(pwrseq_circular_deps_chain),
+	KUNIT_CASE(pwrseq_register_valid),
+	KUNIT_CASE(pwrseq_register_invalid_args),
+	KUNIT_CASE(pwrseq_register_target_without_unit),
+	KUNIT_CASE(pwrseq_enable_disable),
+	KUNIT_CASE(pwrseq_shared_deps),
+	KUNIT_CASE(pwrseq_enable_idempotent),
+	KUNIT_CASE(pwrseq_enable_enable_error),
+	KUNIT_CASE(pwrseq_enable_rollback_on_top_failure),
+	KUNIT_CASE(pwrseq_enable_post_enable),
+	KUNIT_CASE(pwrseq_get_target_not_found),
+	KUNIT_CASE(pwrseq_put_disables_powered_desc),
+	KUNIT_CASE(pwrseq_unregister_with_active_user),
+	KUNIT_CASE(pwrseq_to_device_test),
+	{ }
+};
+
+static struct kunit_suite pwrseq_test_suite = {
+	.name = "pwrseq",
+	.init = pwrseq_test_parent_init,
+	.test_cases = pwrseq_tests,
+};
+
+/*
+ * Match a consumer to this test provider by resolving its "pwrseq-provider"
+ * software-node reference and comparing it to the provider's own fwnode.
+ */
+static int pwrseq_test_match_by_swnode_ref(struct pwrseq_device *pwrseq,
+					   struct device *dev)
+{
+	const struct software_node *provider_swnode;
+	struct fwnode_handle *provider_fwnode, *ref;
+	bool match;
+
+	if (!dev_fwnode(dev))
+		return PWRSEQ_NO_MATCH;
+
+	ref = fwnode_find_reference(dev_fwnode(dev), "pwrseq-provider", 0);
+	if (IS_ERR_OR_NULL(ref))
+		return PWRSEQ_NO_MATCH;
+
+	provider_swnode = pwrseq_device_get_drvdata(pwrseq);
+	provider_fwnode = software_node_fwnode(provider_swnode);
+	match = (ref == provider_fwnode);
+	fwnode_handle_put(ref);
+
+	return match ? PWRSEQ_MATCH_OK : PWRSEQ_NO_MATCH;
+}
+
+static const struct pwrseq_unit_data pwrseq_swnode_test_unit = {
+	.name = "test-target",
+};
+
+static const struct pwrseq_target_data pwrseq_swnode_test_target = {
+	.name = "test-target",
+	.unit = &pwrseq_swnode_test_unit,
+};
+
+static const struct pwrseq_target_data *pwrseq_swnode_test_targets[] = {
+	&pwrseq_swnode_test_target,
+	NULL,
+};
+
+struct pwrseq_swnode_provider_pdata {
+	const struct software_node *provider_swnode;
+};
+
+static int pwrseq_swnode_provider_probe(struct platform_device *pdev)
+{
+	const struct pwrseq_swnode_provider_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct pwrseq_config config;
+
+	config = (struct pwrseq_config){
+		.parent = &pdev->dev,
+		.drvdata = (void *)pdata->provider_swnode,
+		.match = pwrseq_test_match_by_swnode_ref,
+		.targets = pwrseq_swnode_test_targets,
+	};
+
+	return PTR_ERR_OR_ZERO(devm_pwrseq_device_register(&pdev->dev, &config));
+}
+
+static struct platform_driver pwrseq_swnode_provider_driver = {
+	.probe = pwrseq_swnode_provider_probe,
+	.driver = {
+		.name = PWRSEQ_SWNODE_TEST_PROVIDER,
+	},
+};
+
+static struct platform_driver pwrseq_swnode_provider_driver_2 = {
+	.probe = pwrseq_swnode_provider_probe,
+	.driver = {
+		.name = PWRSEQ_SWNODE_TEST_PROVIDER_2,
+	},
+};
+
+struct pwrseq_probe_order_pdata {
+	unsigned int probe_count;
+	int pwrseq_err;
+};
+
+static const struct pwrseq_probe_order_pdata pwrseq_probe_order_pdata_template;
+
+static int pwrseq_probe_order_consumer_probe(struct platform_device *pdev)
+{
+	struct pwrseq_probe_order_pdata *pdata = dev_get_platdata(&pdev->dev);
+	struct pwrseq_desc *desc;
+
+	pdata->probe_count++;
+
+	desc = devm_pwrseq_get(&pdev->dev, "test-target");
+	pdata->pwrseq_err = PTR_ERR_OR_ZERO(desc);
+	if (IS_ERR(desc))
+		return PTR_ERR(desc);
+
+	return 0;
+}
+
+static struct platform_driver pwrseq_probe_order_consumer_driver = {
+	.probe = pwrseq_probe_order_consumer_probe,
+	.driver = {
+		.name = PWRSEQ_PROBE_ORDER_TEST_CONSUMER,
+	},
+};
+
+static struct platform_driver pwrseq_probe_defer_consumer_driver = {
+	.probe = pwrseq_probe_order_consumer_probe,
+	.driver = {
+		.name = PWRSEQ_PROBE_DEFER_TEST_CONSUMER,
+	},
+};
+
+/*
+ * Verify that driver core orders the probe of a pwrseq consumer after its
+ * provider. The consumer references the provider through a software node and
+ * is registered first and we rely on devlink for ordering.
+ */
+static void pwrseq_swnode_probe_order(struct kunit *test)
+{
+	struct property_entry properties[2] = { };
+	struct pwrseq_probe_order_pdata *pdata;
+	struct platform_device_info pdevinfo;
+	struct platform_device *prvd, *cons;
+	struct fwnode_handle *fwnode;
+	bool bound = false;
+	int ret;
+
+	ret = kunit_platform_driver_register(test, &pwrseq_swnode_provider_driver);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = kunit_platform_driver_register(test, &pwrseq_probe_order_consumer_driver);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	fwnode = kunit_software_node_register(test, &pwrseq_test_provider_swnode);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fwnode);
+
+	properties[0] = PROPERTY_ENTRY_REF("pwrseq-provider",
+					   &pwrseq_test_provider_swnode);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_PROBE_ORDER_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+		.data = &pwrseq_probe_order_pdata_template,
+		.size_data = sizeof(pwrseq_probe_order_pdata_template),
+		.properties = properties,
+	};
+
+	cons = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons);
+
+	wait_for_device_probe();
+	scoped_guard(device, &cons->dev)
+		bound = device_is_bound(&cons->dev);
+
+	KUNIT_ASSERT_FALSE(test, bound);
+
+	pdata = dev_get_platdata(&cons->dev);
+	KUNIT_ASSERT_EQ(test, pdata->probe_count, 0);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_SWNODE_TEST_PROVIDER,
+		.id = PLATFORM_DEVID_NONE,
+		.swnode = &pwrseq_test_provider_swnode,
+		.data = &(const struct pwrseq_swnode_provider_pdata){
+			.provider_swnode = &pwrseq_test_provider_swnode,
+		},
+		.size_data = sizeof(struct pwrseq_swnode_provider_pdata),
+	};
+
+	prvd = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, prvd);
+
+	wait_for_device_probe();
+
+	scoped_guard(device, &prvd->dev)
+		bound = device_is_bound(&prvd->dev);
+	KUNIT_ASSERT_TRUE(test, bound);
+
+	scoped_guard(device, &cons->dev)
+		bound = device_is_bound(&cons->dev);
+	KUNIT_ASSERT_TRUE(test, bound);
+
+	pdata = dev_get_platdata(&cons->dev);
+	KUNIT_EXPECT_EQ(test, pdata->probe_count, 1);
+	KUNIT_EXPECT_EQ(test, pdata->pwrseq_err, 0);
+}
+
+/*
+ * Verify that a pwrseq consumer referencing a provider whose software node is
+ * not registered yet, defers its probe instead of failing.
+ *
+ * The provider software node is deliberately left unregistered when the
+ * consumer is added. fw_devlink cannot resolve the reference, so it creates no
+ * supplier link and does not order the consumer - the consumer's probe() runs
+ * and calls pwrseq_get(), which finds no matching provider and returns
+ * -EPROBE_DEFER. Once the provider software node and device appear, the
+ * deferred consumer probes again and binds.
+ */
+static void pwrseq_swnode_probe_defer_on_unregistered(struct kunit *test)
+{
+	struct property_entry properties[2] = { };
+	struct pwrseq_probe_order_pdata *pdata;
+	struct platform_device_info pdevinfo;
+	struct platform_device *prvd, *cons;
+	struct fwnode_handle *fwnode;
+	bool bound = false;
+	int ret;
+
+	ret = kunit_platform_driver_register(test, &pwrseq_swnode_provider_driver_2);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	ret = kunit_platform_driver_register(test, &pwrseq_probe_defer_consumer_driver);
+	KUNIT_ASSERT_EQ(test, ret, 0);
+
+	properties[0] = PROPERTY_ENTRY_REF("pwrseq-provider",
+					   &pwrseq_test_provider_swnode);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_PROBE_DEFER_TEST_CONSUMER,
+		.id = PLATFORM_DEVID_NONE,
+		.data = &pwrseq_probe_order_pdata_template,
+		.size_data = sizeof(pwrseq_probe_order_pdata_template),
+		.properties = properties,
+	};
+
+	cons = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, cons);
+
+	wait_for_device_probe();
+	scoped_guard(device, &cons->dev)
+		bound = device_is_bound(&cons->dev);
+
+	KUNIT_ASSERT_FALSE(test, bound);
+
+	pdata = dev_get_platdata(&cons->dev);
+	KUNIT_ASSERT_GT(test, pdata->probe_count, 0);
+	KUNIT_ASSERT_EQ(test, pdata->pwrseq_err, -EPROBE_DEFER);
+
+	fwnode = kunit_software_node_register(test, &pwrseq_test_provider_swnode);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fwnode);
+
+	pdevinfo = (struct platform_device_info){
+		.name = PWRSEQ_SWNODE_TEST_PROVIDER_2,
+		.id = PLATFORM_DEVID_NONE,
+		.swnode = &pwrseq_test_provider_swnode,
+		.data = &(const struct pwrseq_swnode_provider_pdata){
+			.provider_swnode = &pwrseq_test_provider_swnode,
+		},
+		.size_data = sizeof(struct pwrseq_swnode_provider_pdata),
+	};
+
+	prvd = kunit_platform_device_register_full(test, &pdevinfo);
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, prvd);
+
+	wait_for_device_probe();
+
+	scoped_guard(device, &prvd->dev)
+		bound = device_is_bound(&prvd->dev);
+	KUNIT_ASSERT_TRUE(test, bound);
+
+	scoped_guard(device, &cons->dev)
+		bound = device_is_bound(&cons->dev);
+	KUNIT_ASSERT_TRUE(test, bound);
+
+	pdata = dev_get_platdata(&cons->dev);
+	KUNIT_EXPECT_EQ(test, pdata->pwrseq_err, 0);
+}
+
+static int pwrseq_swnode_test_init(struct kunit *test)
+{
+	/*
+	 * A device link teardown from an earlier test case, or from this
+	 * suite's previous module load, may still be queued on device_link_mq.
+	 * Flush it so software_node_register() below doesn't spuriously see
+	 * the about-to-be-reused node name as still taken.
+	 */
+	device_link_wait_removal();
+
+	return 0;
+}
+
+static struct kunit_case pwrseq_swnode_probe_order_tests[] = {
+	KUNIT_CASE(pwrseq_swnode_probe_order),
+	KUNIT_CASE(pwrseq_swnode_probe_defer_on_unregistered),
+	{ }
+};
+
+static struct kunit_suite pwrseq_swnode_probe_order_test_suite = {
+	.name = "pwrseq-swnode-probe-order",
+	.init = pwrseq_swnode_test_init,
+	.test_cases = pwrseq_swnode_probe_order_tests,
+};
+
+kunit_test_suites(&pwrseq_test_suite,
+		  &pwrseq_swnode_probe_order_test_suite);
+
+MODULE_DESCRIPTION("KUnit test cases for the power sequencing subsystem");
+MODULE_AUTHOR("Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>");
+MODULE_LICENSE("GPL");

-- 
2.47.3