iio: proximity: isl29501: Fix return type of isl29501_register_writegrafted

isl29501_register_write() was returning a u32 instead of an int.
Since the function returns negative error codes (such as -ERANGE or
return values from i2c_smbus_write_byte_data()), returning an unsigned
integer type prevents callers from correctly checking for negative error
conditions.

Fix this by changing the function return type from u32 to int.

This was found through manual code review.

Fixes: 1c28799257bc ("iio: light: isl29501: Add support for the ISL29501 ToF sensor.")
Signed-off-by: Salah Triki <salah.triki@gmail.com>
Reviewed-by: Joshua Crofts <joshua.crofts1@gmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Jonathan Cameron <jonathan.cameron@oss.qualcomm.com>

3 files changed, 189 insertions, 0 deletions

diff --git a/drivers/input/tests/.kunitconfig b/drivers/input/tests/.kunitconfig
new file mode 100644
index 000000000..2f5bedf80
--- /dev/null
+++ b/drivers/input/tests/.kunitconfig
@@ -0,0 +1,3 @@
+CONFIG_KUNIT=y
+CONFIG_INPUT=y
+CONFIG_INPUT_KUNIT_TEST=y
diff --git a/drivers/input/tests/Makefile b/drivers/input/tests/Makefile
new file mode 100644
index 000000000..90cf95418
--- /dev/null
+++ b/drivers/input/tests/Makefile
@@ -0,0 +1,3 @@
+# SPDX-License-Identifier: GPL-2.0
+
+obj-$(CONFIG_INPUT_KUNIT_TEST) += input_test.o
diff --git a/drivers/input/tests/input_test.c b/drivers/input/tests/input_test.c
new file mode 100644
index 000000000..e105ce71a
--- /dev/null
+++ b/drivers/input/tests/input_test.c
@@ -0,0 +1,183 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit test for the input core.
+ *
+ * Copyright (c) 2023 Red Hat Inc
+ */
+
+#include <linux/delay.h>
+#include <linux/input.h>
+
+#include <kunit/test.h>
+
+#define POLL_INTERVAL 100
+
+static int input_test_init(struct kunit *test)
+{
+	struct input_dev *input_dev;
+	int ret;
+
+	input_dev = input_allocate_device();
+	KUNIT_ASSERT_NOT_ERR_OR_NULL(test, input_dev);
+
+	input_dev->name = "Test input device";
+	input_dev->id.bustype = BUS_VIRTUAL;
+	input_dev->id.vendor = 1;
+	input_dev->id.product = 1;
+	input_dev->id.version = 1;
+	input_set_capability(input_dev, EV_KEY, BTN_LEFT);
+	input_set_capability(input_dev, EV_KEY, BTN_RIGHT);
+
+	ret = input_register_device(input_dev);
+	if (ret) {
+		input_free_device(input_dev);
+		KUNIT_FAIL_AND_ABORT(test, "Register device failed: %d", ret);
+	}
+
+	test->priv = input_dev;
+
+	return 0;
+}
+
+static void input_test_exit(struct kunit *test)
+{
+	struct input_dev *input_dev = test->priv;
+
+	if (input_dev)
+		input_unregister_device(input_dev);
+}
+
+static void input_test_poll(struct input_dev *input) { }
+
+static void input_test_polling(struct kunit *test)
+{
+	struct input_dev *input_dev = test->priv;
+
+	/* Must fail because a poll handler has not been set-up yet */
+	KUNIT_ASSERT_EQ(test, input_get_poll_interval(input_dev), -EINVAL);
+
+	KUNIT_ASSERT_EQ(test, input_setup_polling(input_dev, input_test_poll), 0);
+
+	input_set_poll_interval(input_dev, POLL_INTERVAL);
+
+	/* Must succeed because poll handler was set-up and poll interval set */
+	KUNIT_ASSERT_EQ(test, input_get_poll_interval(input_dev), POLL_INTERVAL);
+}
+
+static void input_test_timestamp(struct kunit *test)
+{
+	const ktime_t invalid_timestamp = ktime_set(0, 0);
+	struct input_dev *input_dev = test->priv;
+	ktime_t *timestamp, time;
+
+	timestamp = input_get_timestamp(input_dev);
+	time = timestamp[INPUT_CLK_MONO];
+
+	/* The returned timestamp must always be valid */
+	KUNIT_ASSERT_EQ(test, ktime_compare(time, invalid_timestamp), 1);
+
+	time = ktime_get();
+	input_set_timestamp(input_dev, time);
+
+	timestamp = input_get_timestamp(input_dev);
+	/* The timestamp must be the same than set before */
+	KUNIT_ASSERT_EQ(test, ktime_compare(timestamp[INPUT_CLK_MONO], time), 0);
+}
+
+static void input_test_match_device_id(struct kunit *test)
+{
+	struct input_dev *input_dev = test->priv;
+	struct input_device_id id = { 0 };
+
+	/*
+	 * Must match when the input device bus, vendor, product, version
+	 * and events capable of handling are the same and fail to match
+	 * otherwise.
+	 */
+	id.flags = INPUT_DEVICE_ID_MATCH_BUS;
+	id.bustype = BUS_VIRTUAL;
+	KUNIT_ASSERT_TRUE(test, input_match_device_id(input_dev, &id));
+
+	id.bustype = BUS_I2C;
+	KUNIT_ASSERT_FALSE(test, input_match_device_id(input_dev, &id));
+
+	id.flags = INPUT_DEVICE_ID_MATCH_VENDOR;
+	id.vendor = 1;
+	KUNIT_ASSERT_TRUE(test, input_match_device_id(input_dev, &id));
+
+	id.vendor = 2;
+	KUNIT_ASSERT_FALSE(test, input_match_device_id(input_dev, &id));
+
+	id.flags = INPUT_DEVICE_ID_MATCH_PRODUCT;
+	id.product = 1;
+	KUNIT_ASSERT_TRUE(test, input_match_device_id(input_dev, &id));
+
+	id.product = 2;
+	KUNIT_ASSERT_FALSE(test, input_match_device_id(input_dev, &id));
+
+	id.flags = INPUT_DEVICE_ID_MATCH_VERSION;
+	id.version = 1;
+	KUNIT_ASSERT_TRUE(test, input_match_device_id(input_dev, &id));
+
+	id.version = 2;
+	KUNIT_ASSERT_FALSE(test, input_match_device_id(input_dev, &id));
+
+	id.flags = INPUT_DEVICE_ID_MATCH_EVBIT;
+	__set_bit(EV_KEY, id.evbit);
+	KUNIT_ASSERT_TRUE(test, input_match_device_id(input_dev, &id));
+
+	__set_bit(EV_ABS, id.evbit);
+	KUNIT_ASSERT_FALSE(test, input_match_device_id(input_dev, &id));
+}
+
+static void input_test_grab(struct kunit *test)
+{
+	struct input_dev *input_dev = test->priv;
+	struct input_handle test_handle;
+	struct input_handler handler;
+	struct input_handle handle;
+	struct input_device_id id;
+	int res;
+
+	handler.name = "handler";
+	handler.id_table = &id;
+
+	handle.dev = input_get_device(input_dev);
+	handle.name = dev_name(&input_dev->dev);
+	handle.handler = &handler;
+	res = input_grab_device(&handle);
+	KUNIT_ASSERT_TRUE(test, res == 0);
+
+	test_handle.dev = input_get_device(input_dev);
+	test_handle.name = dev_name(&input_dev->dev);
+	test_handle.handler = &handler;
+	res = input_grab_device(&test_handle);
+	KUNIT_ASSERT_EQ(test, res, -EBUSY);
+
+	input_release_device(&handle);
+	input_put_device(input_dev);
+	res = input_grab_device(&test_handle);
+	KUNIT_ASSERT_TRUE(test, res == 0);
+	input_put_device(input_dev);
+}
+
+static struct kunit_case input_tests[] = {
+	KUNIT_CASE(input_test_polling),
+	KUNIT_CASE(input_test_timestamp),
+	KUNIT_CASE(input_test_match_device_id),
+	KUNIT_CASE(input_test_grab),
+	{ /* sentinel */ }
+};
+
+static struct kunit_suite input_test_suite = {
+	.name = "input_core",
+	.init = input_test_init,
+	.exit = input_test_exit,
+	.test_cases = input_tests,
+};
+
+kunit_test_suite(input_test_suite);
+
+MODULE_AUTHOR("Javier Martinez Canillas <javierm@redhat.com>");
+MODULE_DESCRIPTION("KUnit test for the input core");
+MODULE_LICENSE("GPL");