[PATCH 0/2] gpio: add kunit tests for GPIO core

[Bartosz Golaszewski]

This series adds a first batch of kunit tests for GPIO core. I intend to
gradually add more coverage for functionalities that can't really be
tested from user-space with the existing kernel selftests or libgpiod
tests.

Merging strategy: with an Ack from kunit maintainers, this can go
through the GPIO tree for v7.2.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---
Bartosz Golaszewski (2):
kunit: provide kunit_platform_device_register_full()
gpio: add kunit test cases for the GPIO subsystem

drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +
drivers/gpio/gpiolib-kunit.c | 354 ++++++++++++++++++++++++++++++++++++++++
include/kunit/platform_device.h | 4 +
lib/kunit/platform.c | 31 ++++
5 files changed, 398 insertions(+)
---
base-commit: 4a1989fb6514ca2a4b157ff4700bdcc8bdd9a978
change-id: 20260326-gpiolib-kunit-d7f1b5541ffa

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

[Bartosz Golaszewski]

Provide a kunit-managed variant of platform_device_register_full().

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

include/kunit/platform_device.h | 4 ++++
lib/kunit/platform.c | 31 +++++++++++++++++++++++++++++++
2 files changed, 35 insertions(+)

diff --git a/include/kunit/platform_device.h b/include/kunit/platform_device.h
index f8236a8536f7ebcee6b0e00a7bd799a14b345c1b..8cad6e1c3e7efba862862b579089f2f317784a73 100644
--- a/include/kunit/platform_device.h
+++ b/include/kunit/platform_device.h
@@ -6,10 +6,14 @@ struct completion;
struct kunit;
struct platform_device;
struct platform_driver;
+struct platform_device_info;

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);
+struct platform_device *
+kunit_platform_device_register_full(struct kunit *test,
+ const struct platform_device_info *pdevinfo);

int kunit_platform_device_prepare_wait_for_probe(struct kunit *test,
struct platform_device *pdev,
diff --git a/lib/kunit/platform.c b/lib/kunit/platform.c
index 0b518de26065d65dac3bd49dd94a4b3e7ea0634b..583b50b538c79599ebbf33e261fe2e9ced35efa9 100644
--- a/lib/kunit/platform.c
+++ b/lib/kunit/platform.c
@@ -6,6 +6,7 @@
#include <linux/completion.h>
#include <linux/device/bus.h>
#include <linux/device/driver.h>
+#include <linux/err.h>
#include <linux/platform_device.h>

#include <kunit/platform_device.h>
@@ -130,6 +131,36 @@ int kunit_platform_device_add(struct kunit *test, struct platform_device *pdev)
}
EXPORT_SYMBOL_GPL(kunit_platform_device_add);

+/**
+ * kunit_platform_device_register_full() - Register a KUnit test-managed platform
+ * device described by platform device info
+ * @test: test context
+ * @pdevinfo: platform device information describing the new device
+ *
+ * Register a test-managed platform device. The device is unregistered when the
+ * test completes.
+ *
+ * Return: New platform device on success, IS_ERR() on error.
+ */
+struct platform_device *
+kunit_platform_device_register_full(struct kunit *test,
+ const struct platform_device_info *pdevinfo)
+{
+ struct platform_device *pdev;
+ int ret;
+
+ pdev = platform_device_register_full(pdevinfo);
+ if (IS_ERR(pdev))
+ return pdev;
+
+ ret = kunit_add_action_or_reset(test, platform_device_unregister_wrapper, pdev);
+ if (ret)
+ return ERR_PTR(ret);
+
+ return pdev;
+}
+EXPORT_SYMBOL_GPL(kunit_platform_device_register_full);
+
struct kunit_platform_device_probe_nb {
struct completion *x;
struct device *dev;

--
2.47.3

[Bartosz Golaszewski]

Add a module containing kunit test cases for GPIO core. The idea is to
use it to test functionalities that can't easily be tested from
user-space with kernel selftests or GPIO character device test suites
provided by the libgpiod package.

For now add test cases that verify software node based lookup and ensure
that a GPIO provider unbinding with active consumers does not cause a
crash.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +

drivers/gpio/gpiolib-kunit.c | 354 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 363 insertions(+)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 020e51e30317a8574638bbe31365a3cf49591641..2ed9ba8d9c12b0fec9f6fa3fe6077f5588bf719c 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -102,6 +102,14 @@ config GPIO_CDEV_V1
This ABI version is deprecated.
Please use the latest ABI for new developments.

+config GPIO_KUNIT
+ tristate "Build GPIO Kunit test cases"
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ Say Y here to build the module containing Kunit test cases verifying
+ the functionality of the GPIO subsystem.
+
config GPIO_GENERIC
depends on HAS_IOMEM # Only for IOMEM drivers
tristate
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index b267598b517de089cf6339d837264f1d09e275c0..b01163c6a94db1aa21d895fb897e87be62b816e4 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o
gpiolib-acpi-y := gpiolib-acpi-core.o gpiolib-acpi-quirks.o
obj-$(CONFIG_GPIOLIB) += gpiolib-swnode.o
obj-$(CONFIG_GPIO_SHARED) += gpiolib-shared.o
+obj-$(CONFIG_GPIO_KUNIT) += gpiolib-kunit.o

# Device drivers. Generally keep list sorted alphabetically
obj-$(CONFIG_GPIO_REGMAP) += gpio-regmap.o
diff --git a/drivers/gpio/gpiolib-kunit.c b/drivers/gpio/gpiolib-kunit.c
new file mode 100644
index 0000000000000000000000000000000000000000..f45ba72362f82387d7e345fe57c6ae976265ff9c
--- /dev/null
+++ b/drivers/gpio/gpiolib-kunit.c
@@ -0,0 +1,354 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) Qualcomm Technologies, Inc. and/or its subsidiaries
+ */
+
+#include <linux/fwnode.h>
+#include <linux/gpio/consumer.h>
+#include <linux/gpio/driver.h>
+#include <linux/gpio/machine.h>
+#include <linux/gpio/property.h>
+#include <linux/notifier.h>
+#include <linux/platform_device.h>
+#include <linux/property.h>
+
+#include <kunit/platform_device.h>
+#include <kunit/test.h>
+
+#define GPIO_TEST_PROVIDER "gpio-test-provider"
+#define GPIO_SWNODE_TEST_CONSUMER "gpio-swnode-test-consumer"
+#define GPIO_UNBIND_TEST_CONSUMER "gpio-unbind-test-consumer"
+
+static int gpio_test_provider_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+ return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int gpio_test_provider_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+ return 0;
+}
+
+static int gpio_test_provider_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct gpio_chip *gc;
+
+ gc = devm_kzalloc(dev, sizeof(*gc), GFP_KERNEL);
+ if (!gc)
+ return -ENOMEM;
+
+ gc->base = -1;
+ gc->ngpio = 4;
+ gc->label = "gpio-swnode-consumer-test-device";
+ gc->parent = dev;
+ gc->owner = THIS_MODULE;
+
+ gc->get_direction = gpio_test_provider_get_direction;
+ gc->set = gpio_test_provider_set;
+
+ return devm_gpiochip_add_data(dev, gc, NULL);
+}
+
+static struct platform_driver gpio_test_provider_driver = {
+ .probe = gpio_test_provider_probe,
+ .driver = {
+ .name = GPIO_TEST_PROVIDER,
+ },
+};
+
+static const struct software_node gpio_test_provider_swnode = {
+ .name = "gpio-test-provider-primary",
+};
+
+struct gpio_swnode_consumer_pdata {
+ bool gpio_ok;
+};
+
+static const struct gpio_swnode_consumer_pdata gpio_swnode_pdata_template = {
+ .gpio_ok = false,
+};
+
+static int gpio_swnode_consumer_probe(struct platform_device *pdev)
+{
+ struct device *dev = &pdev->dev;
+ struct gpio_swnode_consumer_pdata *pdata = dev_get_platdata(dev);
+ struct gpio_desc *desc;
+
+ desc = devm_gpiod_get(dev, "foo", GPIOD_OUT_HIGH);
+ if (IS_ERR(desc))
+ return PTR_ERR(desc);
+
+ pdata->gpio_ok = true;
+
+ return 0;
+}
+
+static struct platform_driver gpio_swnode_consumer_driver = {
+ .probe = gpio_swnode_consumer_probe,
+ .driver = {
+ .name = GPIO_SWNODE_TEST_CONSUMER,
+ },
+};
+
+static void gpio_swnode_lookup_by_primary(struct kunit *test)
+{
+ struct gpio_swnode_consumer_pdata *pdata;
+ struct platform_device_info pdevinfo;
+ struct property_entry properties[2];

+ struct platform_device *pdev;
+ int ret;
+

+ ret = kunit_platform_driver_register(test, &gpio_test_provider_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ ret = kunit_platform_driver_register(test, &gpio_swnode_consumer_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_TEST_PROVIDER,
+ .id = PLATFORM_DEVID_NONE,
+ .swnode = &gpio_test_provider_swnode,
+ };
+
+ pdev = kunit_platform_device_register_full(test, &pdevinfo);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+ properties[0] = PROPERTY_ENTRY_GPIO("foo-gpios",
+ &gpio_test_provider_swnode,
+ 0, GPIO_ACTIVE_HIGH);
+ properties[1] = (struct property_entry){ };
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_SWNODE_TEST_CONSUMER,
+ .id = PLATFORM_DEVID_NONE,
+ .data = &gpio_swnode_pdata_template,
+ .size_data = sizeof(gpio_swnode_pdata_template),
+ .properties = properties,
+ };
+
+ 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)
+ KUNIT_ASSERT_TRUE(test, device_is_bound(&pdev->dev));
+
+ pdata = dev_get_platdata(&pdev->dev);
+ KUNIT_ASSERT_TRUE(test, pdata->gpio_ok);
+}
+
+static void gpio_swnode_lookup_by_secondary(struct kunit *test)
+{
+ struct gpio_swnode_consumer_pdata *pdata;
+ struct platform_device_info pdevinfo;
+ struct property_entry properties[2];
+ struct fwnode_handle *primary;

+ struct platform_device *pdev;
+ int ret;
+

+ /*
+ * Can't live on the stack as it will still get referenced in cleanup
+ * path after this function returns.
+ */
+ primary = kunit_kzalloc(test, sizeof(*primary), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, primary);
+
+ ret = kunit_platform_driver_register(test, &gpio_test_provider_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ ret = kunit_platform_driver_register(test, &gpio_swnode_consumer_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ fwnode_init(primary, NULL);
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_TEST_PROVIDER,
+ .id = PLATFORM_DEVID_NONE,
+ .fwnode = primary,
+ .swnode = &gpio_test_provider_swnode,
+ };
+
+ pdev = kunit_platform_device_register_full(test, &pdevinfo);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev);
+
+ properties[0] = PROPERTY_ENTRY_GPIO("foo-gpios",
+ &gpio_test_provider_swnode,
+ 0, GPIO_ACTIVE_HIGH);
+ properties[1] = (struct property_entry){ };
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_SWNODE_TEST_CONSUMER,
+ .id = PLATFORM_DEVID_NONE,
+ .data = &gpio_swnode_pdata_template,
+ .size_data = sizeof(gpio_swnode_pdata_template),
+ .properties = properties,
+ };
+
+ 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)
+ KUNIT_ASSERT_TRUE(test, device_is_bound(&pdev->dev));
+
+ pdata = dev_get_platdata(&pdev->dev);
+ KUNIT_ASSERT_TRUE(test, pdata->gpio_ok);
+}
+
+static struct kunit_case gpio_swnode_lookup_tests[] = {
+ KUNIT_CASE(gpio_swnode_lookup_by_primary),
+ KUNIT_CASE(gpio_swnode_lookup_by_secondary),
+ { }
+};
+
+static struct kunit_suite gpio_swnode_lookup_test_suite = {
+ .name = "gpio-swnode-lookup",
+ .test_cases = gpio_swnode_lookup_tests,
+};
+
+static BLOCKING_NOTIFIER_HEAD(gpio_unbind_notifier);
+
+struct gpio_unbind_consumer_drvdata {
+ struct device *dev;
+ struct gpio_desc *desc;
+ struct notifier_block nb;
+ int set_retval;
+};
+
+static int gpio_unbind_notify(struct notifier_block *nb, unsigned long action,
+ void *data)
+{
+ struct gpio_unbind_consumer_drvdata *drvdata =
+ container_of(nb, struct gpio_unbind_consumer_drvdata, nb);
+ struct device *dev = data;
+
+ if (dev != drvdata->dev)
+ return NOTIFY_DONE;
+
+ drvdata->set_retval = gpiod_set_value_cansleep(drvdata->desc, 0);
+
+ return NOTIFY_OK;
+}
+
+static void gpio_unbind_unregister_notifier(void *data)
+{
+ struct notifier_block *nb = data;
+
+ blocking_notifier_chain_unregister(&gpio_unbind_notifier, nb);
+}
+
+static int gpio_unbind_consumer_probe(struct platform_device *pdev)
+{
+ struct gpio_unbind_consumer_drvdata *data;
+ struct device *dev = &pdev->dev;
+ int ret;
+
+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dev = dev;
+
+ data->desc = devm_gpiod_get(dev, "foo", GPIOD_OUT_HIGH);
+ if (IS_ERR(data->desc))
+ return PTR_ERR(data->desc);
+
+ data->nb.notifier_call = gpio_unbind_notify;
+ ret = blocking_notifier_chain_register(&gpio_unbind_notifier, &data->nb);
+ if (ret)
+ return ret;
+
+ ret = devm_add_action_or_reset(dev, gpio_unbind_unregister_notifier, &data->nb);
+ if (ret)
+ return ret;
+
+ platform_set_drvdata(pdev, data);
+
+ return 0;
+}
+
+static struct platform_driver gpio_unbind_consumer_driver = {
+ .probe = gpio_unbind_consumer_probe,
+ .driver = {
+ .name = GPIO_UNBIND_TEST_CONSUMER,
+ },
+};
+
+static void gpio_unbind_with_consumers(struct kunit *test)
+{
+ struct gpio_unbind_consumer_drvdata *cons_data;
+ struct platform_device_info pdevinfo;
+ struct property_entry properties[2];
+ struct platform_device *prvd, *cons;
+ int ret;
+
+ ret = kunit_platform_driver_register(test, &gpio_test_provider_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ ret = kunit_platform_driver_register(test, &gpio_unbind_consumer_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_TEST_PROVIDER,
+ .id = PLATFORM_DEVID_NONE,
+ .swnode = &gpio_test_provider_swnode,
+ };
+
+ prvd = platform_device_register_full(&pdevinfo);
+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, prvd);
+
+ properties[0] = PROPERTY_ENTRY_GPIO("foo-gpios",
+ &gpio_test_provider_swnode,
+ 0, GPIO_ACTIVE_HIGH);
+ properties[1] = (struct property_entry){ };
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_UNBIND_TEST_CONSUMER,
+ .id = PLATFORM_DEVID_NONE,
+ .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)
+ KUNIT_ASSERT_TRUE(test, device_is_bound(&cons->dev));
+
+ platform_device_unregister(prvd);
+
+ ret = blocking_notifier_call_chain(&gpio_unbind_notifier, 0, &cons->dev);
+ KUNIT_ASSERT_EQ(test, ret, NOTIFY_OK);
+
+ scoped_guard(device, &cons->dev) {
+ cons_data = platform_get_drvdata(cons);
+ /*
+ * We can't have KUNIT_ASSERT_EQ() under the guard. Despite
+ * the lock being released automatically, it will complain that
+ * a lock is still taken during a test abort.
+ */
+ ret = cons_data->set_retval;
+ }
+
+ KUNIT_ASSERT_EQ(test, cons_data->set_retval, -ENODEV);
+}
+
+static struct kunit_case gpio_unbind_with_consumers_tests[] = {
+ KUNIT_CASE(gpio_unbind_with_consumers),
+ { }
+};
+
+static struct kunit_suite gpio_unbind_with_consumers_test_suite = {
+ .name = "gpio-unbind-with-consumers",
+ .test_cases = gpio_unbind_with_consumers_tests,
+};
+
+kunit_test_suites(
+ &gpio_swnode_lookup_test_suite,
+ &gpio_unbind_with_consumers_test_suite,
+);
+
+MODULE_DESCRIPTION("Test module for the GPIO subsystem");
+MODULE_AUTHOR("Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>");
+MODULE_LICENSE("GPL");

--
2.47.3

[Bartosz Golaszewski]

This series adds a first batch of kunit tests for GPIO core. I intend to
gradually add more coverage for functionalities that can't really be
tested from user-space with the existing kernel selftests or libgpiod
tests.

Merging strategy: with an Ack from kunit maintainers, this can go
through the GPIO tree for v7.2.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

Changes in v2:
- Remove cases of kunit killing a thread on test failure with device lock
taken
- Fix a platform device leak on test failure
- New patch: provide kunit_platform_device_unregister()
- Link to v1: https://patch.msgid.link/20260518-gpiolib-kun...@oss.qualcomm.com

---
Bartosz Golaszewski (3):
kunit: provide kunit_platform_device_register_full()
kunit: provide kunit_platform_device_unregister()

gpio: add kunit test cases for the GPIO subsystem

drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +

drivers/gpio/gpiolib-kunit.c | 358 ++++++++++++++++++++++++++++++++++++++++
include/kunit/platform_device.h | 6 +
lib/kunit/platform.c | 46 ++++++
5 files changed, 419 insertions(+)
---
base-commit: 80dd246accce631c328ea43294e53b2b2dd2aa32

[Bartosz Golaszewski]

Provide a kunit-managed variant of platform_device_register_full().

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

+ struct platform_device *pdev;
+ int ret;
+

+ pdev = platform_device_register_full(pdevinfo);
+ if (IS_ERR(pdev))
+ return pdev;
+
+ ret = kunit_add_action_or_reset(test, platform_device_unregister_wrapper, pdev);

+ if (ret)

[Bartosz Golaszewski]

Tests may want to unregister a platform device as part of the test case
logic. Using the regular platform_device_register() with kunit
assertions may result in a platform device leak or otherwise requires
cumbersome error handling. Provide a function that unregisters a
kunit-managed platform device and drops the release action from the
test's list.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

include/kunit/platform_device.h | 2 ++
lib/kunit/platform.c | 15 +++++++++++++++
2 files changed, 17 insertions(+)

diff --git a/include/kunit/platform_device.h b/include/kunit/platform_device.h
index 8cad6e1c3e7efba862862b579089f2f317784a73..eee565d5d1d35c1d1bc82b45eb91d21d00c68428 100644
--- a/include/kunit/platform_device.h
+++ b/include/kunit/platform_device.h
@@ -14,6 +14,8 @@ int kunit_platform_device_add(struct kunit *test, struct platform_device *pdev);
struct platform_device *
kunit_platform_device_register_full(struct kunit *test,
const struct platform_device_info *pdevinfo);
+void kunit_platform_device_unregister(struct kunit *test,
+ struct platform_device *pdev);

int kunit_platform_device_prepare_wait_for_probe(struct kunit *test,
struct platform_device *pdev,
diff --git a/lib/kunit/platform.c b/lib/kunit/platform.c

index 583b50b538c79599ebbf33e261fe2e9ced35efa9..ccfbc70b4e12817f60490e8146f7f7773c9a4dbb 100644
--- a/lib/kunit/platform.c
+++ b/lib/kunit/platform.c
@@ -161,6 +161,21 @@ kunit_platform_device_register_full(struct kunit *test,
}
EXPORT_SYMBOL_GPL(kunit_platform_device_register_full);

+/**
+ * kunit_platform_device_unregister() - Unregister a KUnit-managed platform device

+ * @test: test context

+ * @pdev: platform device to unregister
+ *
+ * Unregister a test-managed platform device and cancel its release action.
+ */
+void kunit_platform_device_unregister(struct kunit *test,
+ struct platform_device *pdev)
+{
+ kunit_remove_action(test, platform_device_unregister_wrapper, pdev);
+ platform_device_unregister(pdev);
+}
+EXPORT_SYMBOL_GPL(kunit_platform_device_unregister);

[Bartosz Golaszewski]

Add a module containing kunit test cases for GPIO core. The idea is to
use it to test functionalities that can't easily be tested from
user-space with kernel selftests or GPIO character device test suites
provided by the libgpiod package.

For now add test cases that verify software node based lookup and ensure
that a GPIO provider unbinding with active consumers does not cause a
crash.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +

drivers/gpio/gpiolib-kunit.c | 358 +++++++++++++++++++++++++++++++++++++++++++
3 files changed, 367 insertions(+)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index 00fcab5d09a4294ed778cea78af5867a0f6e481b..0306005fb7d65ae85905e967b9065fd74db753db 100644

--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -102,6 +102,14 @@ config GPIO_CDEV_V1
This ABI version is deprecated.
Please use the latest ABI for new developments.

+config GPIO_KUNIT
+ tristate "Build GPIO Kunit test cases"
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ Say Y here to build the module containing Kunit test cases verifying
+ the functionality of the GPIO subsystem.
+
config GPIO_GENERIC
depends on HAS_IOMEM # Only for IOMEM drivers
tristate
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile

index 2ea47d9d3dca948e1cdc46965e83b0e1b6de5f70..c66b6dd659b16b80b6bb6b15fac3e3f462dec596 100644

--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -13,6 +13,7 @@ obj-$(CONFIG_GPIO_ACPI) += gpiolib-acpi.o
gpiolib-acpi-y := gpiolib-acpi-core.o gpiolib-acpi-quirks.o
obj-$(CONFIG_GPIOLIB) += gpiolib-swnode.o
obj-$(CONFIG_GPIO_SHARED) += gpiolib-shared.o
+obj-$(CONFIG_GPIO_KUNIT) += gpiolib-kunit.o

# Device drivers. Generally keep list sorted alphabetically
obj-$(CONFIG_GPIO_REGMAP) += gpio-regmap.o
diff --git a/drivers/gpio/gpiolib-kunit.c b/drivers/gpio/gpiolib-kunit.c
new file mode 100644

index 0000000000000000000000000000000000000000..380b68f879e55433668353bb88067d561142a5bc
--- /dev/null
+++ b/drivers/gpio/gpiolib-kunit.c
@@ -0,0 +1,358 @@

+ struct platform_device *pdev;
+ bool bound = false;
+ int ret;
+

+ bound = device_is_bound(&pdev->dev);
+
+ KUNIT_ASSERT_TRUE(test, bound);

+
+ pdata = dev_get_platdata(&pdev->dev);
+ KUNIT_ASSERT_TRUE(test, pdata->gpio_ok);
+}
+
+static void gpio_swnode_lookup_by_secondary(struct kunit *test)
+{
+ struct gpio_swnode_consumer_pdata *pdata;
+ struct platform_device_info pdevinfo;
+ struct property_entry properties[2];
+ struct fwnode_handle *primary;

+ struct platform_device *pdev;
+ bool bound = false;
+ int ret;
+

+ bound = device_is_bound(&pdev->dev);
+
+ KUNIT_ASSERT_TRUE(test, bound);

+ int ret;
+

+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dev = dev;
+
+ data->desc = devm_gpiod_get(dev, "foo", GPIOD_OUT_HIGH);
+ if (IS_ERR(data->desc))
+ return PTR_ERR(data->desc);
+
+ data->nb.notifier_call = gpio_unbind_notify;
+ ret = blocking_notifier_chain_register(&gpio_unbind_notifier, &data->nb);

+ if (ret)

+ return ret;
+
+ ret = devm_add_action_or_reset(dev, gpio_unbind_unregister_notifier, &data->nb);

+ if (ret)

+ return ret;
+
+ platform_set_drvdata(pdev, data);
+
+ return 0;
+}
+
+static struct platform_driver gpio_unbind_consumer_driver = {
+ .probe = gpio_unbind_consumer_probe,
+ .driver = {
+ .name = GPIO_UNBIND_TEST_CONSUMER,
+ },
+};
+
+static void gpio_unbind_with_consumers(struct kunit *test)
+{
+ struct gpio_unbind_consumer_drvdata *cons_data;
+ struct platform_device_info pdevinfo;
+ struct property_entry properties[2];
+ struct platform_device *prvd, *cons;

+ bool bound = false;
+ int ret;
+

+ ret = kunit_platform_driver_register(test, &gpio_test_provider_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ ret = kunit_platform_driver_register(test, &gpio_unbind_consumer_driver);
+ KUNIT_ASSERT_EQ(test, ret, 0);
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_TEST_PROVIDER,
+ .id = PLATFORM_DEVID_NONE,
+ .swnode = &gpio_test_provider_swnode,
+ };
+

+ prvd = kunit_platform_device_register_full(test, &pdevinfo);

+ KUNIT_ASSERT_NOT_ERR_OR_NULL(test, prvd);
+
+ properties[0] = PROPERTY_ENTRY_GPIO("foo-gpios",
+ &gpio_test_provider_swnode,
+ 0, GPIO_ACTIVE_HIGH);
+ properties[1] = (struct property_entry){ };
+
+ pdevinfo = (struct platform_device_info){
+ .name = GPIO_UNBIND_TEST_CONSUMER,
+ .id = PLATFORM_DEVID_NONE,
+ .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_TRUE(test, bound);
+
+ kunit_platform_device_unregister(test, prvd);

+
+ ret = blocking_notifier_call_chain(&gpio_unbind_notifier, 0, &cons->dev);
+ KUNIT_ASSERT_EQ(test, ret, NOTIFY_OK);
+
+ scoped_guard(device, &cons->dev) {
+ cons_data = platform_get_drvdata(cons);

+ ret = cons_data->set_retval;
+ }
+

+ KUNIT_ASSERT_EQ(test, ret, -ENODEV);

[Bartosz Golaszewski]

This series adds a first batch of kunit tests for GPIO core. I intend to
gradually add more coverage for functionalities that can't really be
tested from user-space with the existing kernel selftests or libgpiod
tests.

Merging strategy: with an Ack from kunit maintainers, this can go
through the GPIO tree for v7.2.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

Changes in v3:
- Make kunit_platform_device_unregister() handle both cases of platform
devices created with kunit_platform_device_alloc() +
kunit_platform_device_add() and kunit_platform_device_register_full()
(sashiko)
- Link to v2: https://patch.msgid.link/20260520-gpiolib-kun...@oss.qualcomm.com

Changes in v2:
- Remove cases of kunit killing a thread on test failure with device lock
taken
- Fix a platform device leak on test failure
- New patch: provide kunit_platform_device_unregister()
- Link to v1: https://patch.msgid.link/20260518-gpiolib-kun...@oss.qualcomm.com

---
Bartosz Golaszewski (3):
kunit: provide kunit_platform_device_register_full()
kunit: provide kunit_platform_device_unregister()
gpio: add kunit test cases for the GPIO subsystem

drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +

drivers/gpio/gpiolib-kunit.c | 358 ++++++++++++++++++++++++++++++++++++++++
include/kunit/platform_device.h | 6 +

lib/kunit/platform.c | 64 +++++++
5 files changed, 437 insertions(+)

[Bartosz Golaszewski]

Provide a kunit-managed variant of platform_device_register_full().

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

include/kunit/platform_device.h | 4 ++++
lib/kunit/platform.c | 31 +++++++++++++++++++++++++++++++

2 files changed, 35 insertions(+)

diff --git a/include/kunit/platform_device.h b/include/kunit/platform_device.h
index f8236a8536f7ebcee6b0e00a7bd799a14b345c1b..8cad6e1c3e7efba862862b579089f2f317784a73 100644
--- a/include/kunit/platform_device.h
+++ b/include/kunit/platform_device.h

@@ -6,10 +6,14 @@ struct completion;
struct kunit;
struct platform_device;
struct platform_driver;
+struct platform_device_info;

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);

+struct platform_device *
+kunit_platform_device_register_full(struct kunit *test,
+ const struct platform_device_info *pdevinfo);

int kunit_platform_device_prepare_wait_for_probe(struct kunit *test,
struct platform_device *pdev,
diff --git a/lib/kunit/platform.c b/lib/kunit/platform.c

index 0b518de26065d65dac3bd49dd94a4b3e7ea0634b..583b50b538c79599ebbf33e261fe2e9ced35efa9 100644
--- a/lib/kunit/platform.c
+++ b/lib/kunit/platform.c

@@ -6,6 +6,7 @@
#include <linux/completion.h>
#include <linux/device/bus.h>
#include <linux/device/driver.h>
+#include <linux/err.h>
#include <linux/platform_device.h>

#include <kunit/platform_device.h>
@@ -130,6 +131,36 @@ int kunit_platform_device_add(struct kunit *test, struct platform_device *pdev)
}
EXPORT_SYMBOL_GPL(kunit_platform_device_add);

+/**
+ * kunit_platform_device_register_full() - Register a KUnit test-managed platform
+ * device described by platform device info

+ * @test: test context

+ * @pdevinfo: platform device information describing the new device
+ *
+ * Register a test-managed platform device. The device is unregistered when the
+ * test completes.
+ *
+ * Return: New platform device on success, IS_ERR() on error.
+ */
+struct platform_device *
+kunit_platform_device_register_full(struct kunit *test,
+ const struct platform_device_info *pdevinfo)
+{

+ struct platform_device *pdev;

+ int ret;
+
+ pdev = platform_device_register_full(pdevinfo);
+ if (IS_ERR(pdev))
+ return pdev;
+
+ ret = kunit_add_action_or_reset(test, platform_device_unregister_wrapper, pdev);

+ if (ret)

+ return ERR_PTR(ret);
+
+ return pdev;
+}
+EXPORT_SYMBOL_GPL(kunit_platform_device_register_full);

[Bartosz Golaszewski]

Tests may want to unregister a platform device as part of the test case
logic. Using the regular platform_device_register() with kunit
assertions may result in a platform device leak or otherwise requires
cumbersome error handling. Provide a function that unregisters a
kunit-managed platform device and drops the release action from the
test's list.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

include/kunit/platform_device.h | 2 ++
lib/kunit/platform.c | 33 +++++++++++++++++++++++++++++++++

2 files changed, 35 insertions(+)

diff --git a/include/kunit/platform_device.h b/include/kunit/platform_device.h

index 8cad6e1c3e7efba862862b579089f2f317784a73..eee565d5d1d35c1d1bc82b45eb91d21d00c68428 100644
--- a/include/kunit/platform_device.h
+++ b/include/kunit/platform_device.h

@@ -14,6 +14,8 @@ int kunit_platform_device_add(struct kunit *test, struct platform_device *pdev);
struct platform_device *
kunit_platform_device_register_full(struct kunit *test,
const struct platform_device_info *pdevinfo);
+void kunit_platform_device_unregister(struct kunit *test,
+ struct platform_device *pdev);

int kunit_platform_device_prepare_wait_for_probe(struct kunit *test,
struct platform_device *pdev,
diff --git a/lib/kunit/platform.c b/lib/kunit/platform.c

index 583b50b538c79599ebbf33e261fe2e9ced35efa9..737758d710b2839fab29c5cbcf3bc5ba00e20094 100644
--- a/lib/kunit/platform.c
+++ b/lib/kunit/platform.c
@@ -161,6 +161,39 @@ kunit_platform_device_register_full(struct kunit *test,
}
EXPORT_SYMBOL_GPL(kunit_platform_device_register_full);

+static bool
+kunit_platform_device_add_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_add_exit;
+}
+

+/**
+ * kunit_platform_device_unregister() - Unregister a KUnit-managed platform device

+ * @test: test context

+ * @pdev: platform device to unregister
+ *
+ * Unregister a test-managed platform device and cancel its release action.
+ */
+void kunit_platform_device_unregister(struct kunit *test,

+ struct platform_device *pdev)
+{
+ struct kunit_resource *res;
+
+ res = kunit_find_resource(test, kunit_platform_device_add_match, pdev);
+ if (res) {
+ res->free = NULL;
+ kunit_put_resource(res);
+ } else {

+ kunit_remove_action(test, platform_device_unregister_wrapper, pdev);
+ }

+
+ platform_device_unregister(pdev);
+}
+EXPORT_SYMBOL_GPL(kunit_platform_device_unregister);

[Bartosz Golaszewski]

Add a module containing kunit test cases for GPIO core. The idea is to
use it to test functionalities that can't easily be tested from
user-space with kernel selftests or GPIO character device test suites
provided by the libgpiod package.

For now add test cases that verify software node based lookup and ensure
that a GPIO provider unbinding with active consumers does not cause a
crash.

Signed-off-by: Bartosz Golaszewski <bartosz.g...@oss.qualcomm.com>
---

drivers/gpio/Kconfig | 8 +
drivers/gpio/Makefile | 1 +

+static int gpio_test_provider_probe(struct platform_device *pdev)
+{

+static int gpio_swnode_consumer_probe(struct platform_device *pdev)
+{

+ struct platform_device *pdev;
+ bool bound = false;
+ int ret;
+

+ struct platform_device *pdev;
+ bool bound = false;
+ int ret;
+

+static int gpio_unbind_consumer_probe(struct platform_device *pdev)
+{

+ struct gpio_unbind_consumer_drvdata *data;
+ struct device *dev = &pdev->dev;

+ int ret;
+

+ data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL);
+ if (!data)
+ return -ENOMEM;
+
+ data->dev = dev;
+
+ data->desc = devm_gpiod_get(dev, "foo", GPIOD_OUT_HIGH);
+ if (IS_ERR(data->desc))
+ return PTR_ERR(data->desc);
+
+ data->nb.notifier_call = gpio_unbind_notify;
+ ret = blocking_notifier_chain_register(&gpio_unbind_notifier, &data->nb);

+ if (ret)

+ return ret;
+
+ ret = devm_add_action_or_reset(dev, gpio_unbind_unregister_notifier, &data->nb);

+ if (ret)

+ return ret;
+
+ platform_set_drvdata(pdev, data);
+
+ return 0;
+}
+
+static struct platform_driver gpio_unbind_consumer_driver = {
+ .probe = gpio_unbind_consumer_probe,
+ .driver = {
+ .name = GPIO_UNBIND_TEST_CONSUMER,
+ },
+};
+
+static void gpio_unbind_with_consumers(struct kunit *test)
+{
+ struct gpio_unbind_consumer_drvdata *cons_data;
+ struct platform_device_info pdevinfo;
+ struct property_entry properties[2];
+ struct platform_device *prvd, *cons;
+ bool bound = false;

+ int ret;
+