INPUT_CLK_MONO
clk_type = INPUT_CLK_MONO;
dev->timestamp[INPUT_CLK_MONO] = timestamp;
if (!ktime_compare(dev->timestamp[INPUT_CLK_MONO], invalid_timestamp))
dev->timestamp[INPUT_CLK_MONO] = ktime_set(0, 0);
time = timestamp[INPUT_CLK_MONO];
KUNIT_ASSERT_EQ(test, ktime_compare(timestamp[INPUT_CLK_MONO], time), 0);