clk: Introduce Kunit Tests for the framework

Let's test various parts of the rate-related clock API with the kunit
testing framework.

Cc: kunit-dev@googlegroups.com
Tested-by: Daniel Latypov <dlatypov@google.com>
Suggested-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://lore.kernel.org/r/20220225143534.405820-3-maxime@cerno.tech
Signed-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/.kunitconfig

@@ -1,3 +1,4 @@
 CONFIG_KUNIT=y
 CONFIG_COMMON_CLK=y
+CONFIG_CLK_KUNIT_TEST=y
 CONFIG_CLK_GATE_KUNIT_TEST=y

drivers/clk/Kconfig

@@ -429,6 +429,13 @@ source "drivers/clk/xilinx/Kconfig"
 source "drivers/clk/zynqmp/Kconfig"
 
 # Kunit test cases
+config CLK_KUNIT_TEST
+	tristate "Basic Clock Framework Kunit Tests" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Kunit tests for the common clock framework.
+
 config CLK_GATE_KUNIT_TEST
 	tristate "Basic gate type Kunit test" if !KUNIT_ALL_TESTS
 	depends on KUNIT

drivers/clk/Makefile

@@ -2,6 +2,7 @@
 # common clock types
 obj-$(CONFIG_HAVE_CLK)		+= clk-devres.o clk-bulk.o clkdev.o
 obj-$(CONFIG_COMMON_CLK)	+= clk.o
+obj-$(CONFIG_CLK_KUNIT_TEST)	+= clk_test.o
 obj-$(CONFIG_COMMON_CLK)	+= clk-divider.o
 obj-$(CONFIG_COMMON_CLK)	+= clk-fixed-factor.o
 obj-$(CONFIG_COMMON_CLK)	+= clk-fixed-rate.o