Re: [PATCH v3 3/3] gpio: add kunit test cases for the GPIO subsystem

[David Gow]

Le 22/05/2026 à 9:42 PM, Bartosz Golaszewski a écrit :
> 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.golaszewski@xxxxxxxxxxxxxxxx>
> ---

This is a nice looking test, thanks.

Reviewed-by: David Gow <david@xxxxxxxxxxxx>

Happy for this (and the previous two patches) to go in via gpio, but if
you'd rather them go in via the KUnit tree, let me know.

Cheers,
-- David

>  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.
> +


FYI: If you want to add CONFIG_GPIOLIB=y to
tools/testing/kunit/configs/all_tests.config, we can enable these tests
when the --alltests flag is passed to kunit.py.

>  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 @@
> +// 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;
> +	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_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)
> +		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;
> +
> +	/*
> +	 * 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)
> +		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 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;
> +	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);
> +}
> +
> +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.golaszewski@xxxxxxxxxxxxxxxx>");
> +MODULE_LICENSE("GPL");
>