From a05cfd98c5eca766a4a127bde6278095fc367442 Mon Sep 17 00:00:00 2001 From: Bartosz Golaszewski Date: Wed, 10 Jun 2026 15:29:18 +0200 Subject: [PATCH] gpio: kunit: add test cases for software node hogs Add a test suite containing cases verifying that GPIO hogs described with software nodes are correctly setup by GPIO core. Reviewed-by: Linus Walleij Link: https://patch.msgid.link/20260610-gpio-kunit-swnode-hog-v1-2-37b3bf37096c@oss.qualcomm.com Signed-off-by: Bartosz Golaszewski --- drivers/gpio/gpiolib-kunit.c | 254 ++++++++++++++++++++++++++++++++++- 1 file changed, 249 insertions(+), 5 deletions(-) diff --git a/drivers/gpio/gpiolib-kunit.c b/drivers/gpio/gpiolib-kunit.c index d6a80ea03543..c9c5b4374820 100644 --- a/drivers/gpio/gpiolib-kunit.c +++ b/drivers/gpio/gpiolib-kunit.c @@ -18,19 +18,67 @@ #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" +#define GPIO_CONSUMER_NAME "gpio-swnode-consumer-test-device" + +#define GPIO_TEST_PROVIDER_NGPIO 4 + +/* + * The test provider tracks per-line direction and value so that lines can be + * driven as both inputs and outputs - this is needed to exercise input as well + * as output GPIO hogs. + */ +struct gpio_test_provider_data { + DECLARE_BITMAP(is_output, GPIO_TEST_PROVIDER_NGPIO); + DECLARE_BITMAP(values, GPIO_TEST_PROVIDER_NGPIO); +}; static int gpio_test_provider_get_direction(struct gpio_chip *gc, unsigned int offset) { - return GPIO_LINE_DIRECTION_OUT; + struct gpio_test_provider_data *data = gpiochip_get_data(gc); + + return test_bit(offset, data->is_output) ? + GPIO_LINE_DIRECTION_OUT : GPIO_LINE_DIRECTION_IN; +} + +static int gpio_test_provider_direction_input(struct gpio_chip *gc, unsigned int offset) +{ + struct gpio_test_provider_data *data = gpiochip_get_data(gc); + + clear_bit(offset, data->is_output); + + return 0; +} + +static int gpio_test_provider_direction_output(struct gpio_chip *gc, unsigned int offset, + int value) +{ + struct gpio_test_provider_data *data = gpiochip_get_data(gc); + + set_bit(offset, data->is_output); + __assign_bit(offset, data->values, value); + + return 0; +} + +static int gpio_test_provider_get(struct gpio_chip *gc, unsigned int offset) +{ + struct gpio_test_provider_data *data = gpiochip_get_data(gc); + + return test_bit(offset, data->values); } static int gpio_test_provider_set(struct gpio_chip *gc, unsigned int offset, int value) { + struct gpio_test_provider_data *data = gpiochip_get_data(gc); + + __assign_bit(offset, data->values, value); + return 0; } static int gpio_test_provider_probe(struct platform_device *pdev) { + struct gpio_test_provider_data *data; struct device *dev = &pdev->dev; struct gpio_chip *gc; @@ -38,16 +86,26 @@ static int gpio_test_provider_probe(struct platform_device *pdev) if (!gc) return -ENOMEM; + data = devm_kzalloc(dev, sizeof(*data), GFP_KERNEL); + if (!data) + return -ENOMEM; + + /* Lines start as outputs to preserve the default for lookup tests. */ + bitmap_fill(data->is_output, GPIO_TEST_PROVIDER_NGPIO); + gc->base = -1; - gc->ngpio = 4; - gc->label = "gpio-swnode-consumer-test-device"; + gc->ngpio = GPIO_TEST_PROVIDER_NGPIO; + gc->label = GPIO_CONSUMER_NAME; gc->parent = dev; gc->owner = THIS_MODULE; gc->get_direction = gpio_test_provider_get_direction; + gc->direction_input = gpio_test_provider_direction_input; + gc->direction_output = gpio_test_provider_direction_output; + gc->get = gpio_test_provider_get; gc->set = gpio_test_provider_set; - return devm_gpiochip_add_data(dev, gc, NULL); + return devm_gpiochip_add_data(dev, gc, data); } static struct platform_driver gpio_test_provider_driver = { @@ -63,10 +121,12 @@ static const struct software_node gpio_test_provider_swnode = { struct gpio_swnode_consumer_pdata { bool gpio_ok; + int errno; }; static const struct gpio_swnode_consumer_pdata gpio_swnode_pdata_template = { .gpio_ok = false, + .errno = 0, }; static int gpio_swnode_consumer_probe(struct platform_device *pdev) @@ -76,8 +136,10 @@ static int gpio_swnode_consumer_probe(struct platform_device *pdev) struct gpio_desc *desc; desc = devm_gpiod_get(dev, "foo", GPIOD_OUT_HIGH); - if (IS_ERR(desc)) + if (IS_ERR(desc)) { + pdata->errno = PTR_ERR(desc); return PTR_ERR(desc); + } pdata->gpio_ok = true; @@ -348,9 +410,191 @@ static struct kunit_suite gpio_unbind_with_consumers_test_suite = { .test_cases = gpio_unbind_with_consumers_tests, }; +/* + * GPIO line hogs are described by child software nodes of the provider + * carrying the "gpio-hog" property. They are picked up automatically when the + * gpiochip is registered. Each hog below sits on a distinct line of the + * provider. + */ +#define GPIO_HOG_OUTPUT_HIGH_OFFSET 0 +#define GPIO_HOG_OUTPUT_LOW_OFFSET 1 +#define GPIO_HOG_INPUT_OFFSET 2 + +static const u32 gpio_hog_output_high_gpios[] = { + GPIO_HOG_OUTPUT_HIGH_OFFSET, GPIO_ACTIVE_HIGH, +}; + +static const struct property_entry gpio_hog_output_high_properties[] = { + PROPERTY_ENTRY_U32_ARRAY("gpios", gpio_hog_output_high_gpios), + PROPERTY_ENTRY_STRING("line-name", "hog-output-high"), + PROPERTY_ENTRY_BOOL("output-high"), + PROPERTY_ENTRY_BOOL("gpio-hog"), + { } +}; + +static const struct software_node gpio_hog_output_high_swnode = + SOFTWARE_NODE("hog-output-high", gpio_hog_output_high_properties, + &gpio_test_provider_swnode); + +static const u32 gpio_hog_output_low_gpios[] = { + GPIO_HOG_OUTPUT_LOW_OFFSET, GPIO_ACTIVE_HIGH, +}; + +static const struct property_entry gpio_hog_output_low_properties[] = { + PROPERTY_ENTRY_U32_ARRAY("gpios", gpio_hog_output_low_gpios), + PROPERTY_ENTRY_STRING("line-name", "hog-output-low"), + PROPERTY_ENTRY_BOOL("output-low"), + PROPERTY_ENTRY_BOOL("gpio-hog"), + { } +}; + +static const struct software_node gpio_hog_output_low_swnode = + SOFTWARE_NODE("hog-output-low", gpio_hog_output_low_properties, + &gpio_test_provider_swnode); + +static const u32 gpio_hog_input_gpios[] = { + GPIO_HOG_INPUT_OFFSET, GPIO_ACTIVE_HIGH, +}; + +static const struct property_entry gpio_hog_input_properties[] = { + PROPERTY_ENTRY_U32_ARRAY("gpios", gpio_hog_input_gpios), + PROPERTY_ENTRY_STRING("line-name", "hog-input"), + PROPERTY_ENTRY_BOOL("input"), + PROPERTY_ENTRY_BOOL("gpio-hog"), + { } +}; + +static const struct software_node gpio_hog_input_swnode = + SOFTWARE_NODE("hog-input", gpio_hog_input_properties, + &gpio_test_provider_swnode); + +static const struct software_node *const gpio_hog_swnodes[] = { + &gpio_test_provider_swnode, + &gpio_hog_output_high_swnode, + &gpio_hog_output_low_swnode, + &gpio_hog_input_swnode, + NULL +}; + +/* + * Bring up the provider with a single hog child registered and verify both + * that the line was configured with the expected direction and that it is now + * exclusively owned (a consumer asking for the same line fails to bind). + * + * The provider node is referenced by the device through its fwnode rather than + * being handed to .swnode, so the device takes no software node reference of + * its own. Both the provider and the hog child are therefore test-managed and + * torn down (child first) once the test case completes. + */ +static void gpio_hog_assert(struct kunit *test, unsigned int offset, + int expected_direction) +{ + struct gpio_swnode_consumer_pdata *pdata; + struct platform_device_info pdevinfo; + struct property_entry properties[2]; + struct platform_device *pdev; + struct fwnode_handle *fwnode; + struct gpio_desc *desc; + bool bound = true; + int ret; + + fwnode = software_node_fwnode(&gpio_test_provider_swnode); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, fwnode); + + pdevinfo = (struct platform_device_info){ + .name = GPIO_TEST_PROVIDER, + .id = PLATFORM_DEVID_NONE, + .fwnode = fwnode, + }; + + pdev = kunit_platform_device_register_full(test, &pdevinfo); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, pdev); + + wait_for_device_probe(); + + /* The hog must have configured the line with the expected direction. */ + struct gpio_device *gdev __free(gpio_device_put) = + gpio_device_find_by_label(GPIO_CONSUMER_NAME); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, gdev); + + desc = gpio_device_get_desc(gdev, offset); + KUNIT_ASSERT_NOT_ERR_OR_NULL(test, desc); + + ret = gpiod_get_direction(desc); + KUNIT_ASSERT_EQ(test, ret, expected_direction); + + /* A hogged line is owned exclusively, so a consumer must fail to bind. */ + properties[0] = PROPERTY_ENTRY_GPIO("foo-gpios", + &gpio_test_provider_swnode, + offset, 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_FALSE(test, bound); + + pdata = dev_get_platdata(&pdev->dev); + KUNIT_ASSERT_FALSE(test, pdata->gpio_ok); + KUNIT_ASSERT_EQ(test, pdata->errno, -EBUSY); +} + +static void gpio_hog_output_high(struct kunit *test) +{ + gpio_hog_assert(test, GPIO_HOG_OUTPUT_HIGH_OFFSET, GPIO_LINE_DIRECTION_OUT); +} + +static void gpio_hog_output_low(struct kunit *test) +{ + gpio_hog_assert(test, GPIO_HOG_OUTPUT_LOW_OFFSET, GPIO_LINE_DIRECTION_OUT); +} + +static void gpio_hog_input(struct kunit *test) +{ + gpio_hog_assert(test, GPIO_HOG_INPUT_OFFSET, GPIO_LINE_DIRECTION_IN); +} + +static int gpio_hog_suite_init(struct kunit_suite *suite) +{ + return software_node_register_node_group(gpio_hog_swnodes); +} + +static void gpio_hog_suite_exit(struct kunit_suite *suite) +{ + software_node_unregister_node_group(gpio_hog_swnodes); +} + +static struct kunit_case gpio_swnode_hog_tests[] = { + KUNIT_CASE(gpio_hog_output_high), + KUNIT_CASE(gpio_hog_output_low), + KUNIT_CASE(gpio_hog_input), + { } +}; + +static struct kunit_suite gpio_swnode_hog_test_suite = { + .name = "gpio-swnode-hog", + .test_cases = gpio_swnode_hog_tests, + .suite_init = gpio_hog_suite_init, + .suite_exit = gpio_hog_suite_exit, + .init = gpio_swnode_register_drivers, +}; + kunit_test_suites( &gpio_swnode_lookup_test_suite, &gpio_unbind_with_consumers_test_suite, + &gpio_swnode_hog_test_suite, ); MODULE_DESCRIPTION("Test module for the GPIO subsystem");