@@ -2,4 +2,5 @@ CONFIG_KUNIT=y
CONFIG_COMMON_CLK=y
CONFIG_CLK_KUNIT_TEST=y
CONFIG_CLK_GATE_KUNIT_TEST=y
+CONFIG_CLK_FD_KUNIT_TEST=y
CONFIG_UML_PCI_OVER_VIRTIO=n
@@ -513,4 +513,11 @@ config CLK_GATE_KUNIT_TEST
help
Kunit test for the basic clk gate type.
+config CLK_FD_KUNIT_TEST
+ tristate "Basic fractional divider type Kunit test" if !KUNIT_ALL_TESTS
+ depends on KUNIT
+ default KUNIT_ALL_TESTS
+ help
+ Kunit test for the clk-fractional-divider type.
+
endif
@@ -12,6 +12,7 @@ obj-$(CONFIG_COMMON_CLK) += clk-multiplier.o
obj-$(CONFIG_COMMON_CLK) += clk-mux.o
obj-$(CONFIG_COMMON_CLK) += clk-composite.o
obj-$(CONFIG_COMMON_CLK) += clk-fractional-divider.o
+obj-$(CONFIG_CLK_FD_KUNIT_TEST) += clk-fractional-divider_test.o
obj-$(CONFIG_COMMON_CLK) += clk-gpio.o
ifeq ($(CONFIG_OF), y)
obj-$(CONFIG_COMMON_CLK) += clk-conf.o
new file mode 100644
@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Kunit test for clock fractional divider
+ */
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+
+/* Needed for clk_hw_get_clk() */
+#include "clk.h"
+
+/* Needed for clk_fractional_divider_general_approximation */
+#include "clk-fractional-divider.h"
+
+#include <kunit/test.h>
+
+/*
+ * Test the maximum denominator case for fd clock without flags.
+ *
+ * Expect the highest possible denominator to be used in order to get as close as possible to the
+ * requested rate.
+ */
+static void clk_fd_test_approximation_max_denominator(struct kunit *test)
+{
+ struct clk_fractional_divider *fd;
+ struct clk_hw *hw;
+ unsigned long rate, parent_rate, m, n, max_n;
+
+ fd = kunit_kzalloc(test, sizeof(*fd), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_NULL(test, fd);
+
+ fd->mwidth = 3;
+ fd->nwidth = 3;
+ max_n = 7;
+
+ hw = &fd->hw;
+
+ rate = 240000000;
+ parent_rate = (max_n + 1) * rate; /* so that it exceeds the maximum divisor */
+
+ clk_fractional_divider_general_approximation(hw, rate, &parent_rate, &m, &n);
+ KUNIT_EXPECT_EQ(test, parent_rate, (max_n + 1) * rate); /* parent remains unchanged */
+ KUNIT_EXPECT_EQ(test, m, 1);
+ KUNIT_EXPECT_EQ(test, n, max_n);
+}
+
+/*
+ * Test the maximum numerator case for fd clock without flags.
+ *
+ * Expect the highest possible numerator to be used in order to get as close as possible to the
+ * requested rate.
+ */
+static void clk_fd_test_approximation_max_numerator(struct kunit *test)
+{
+ struct clk_fractional_divider *fd;
+ struct clk_hw *hw;
+ unsigned long rate, parent_rate, m, n, max_m;
+
+ fd = kunit_kzalloc(test, sizeof(*fd), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_NULL(test, fd);
+
+ fd->mwidth = 3;
+ max_m = 7;
+ fd->nwidth = 3;
+
+ hw = &fd->hw;
+
+ rate = 240000000;
+ parent_rate = rate / (max_m + 1); /* so that it exceeds the maximum numerator */
+
+ clk_fractional_divider_general_approximation(hw, rate, &parent_rate, &m, &n);
+ KUNIT_EXPECT_EQ(test, parent_rate, rate / (max_m + 1)); /* parent remains unchanged */
+ KUNIT_EXPECT_EQ(test, m, max_m);
+ KUNIT_EXPECT_EQ(test, n, 1);
+}
+
+/*
+ * Test the maximum denominator case for zero based fd clock.
+ *
+ * Expect the highest possible denominator to be used in order to get as close as possible to the
+ * requested rate.
+ */
+static void clk_fd_test_approximation_max_denominator_zero_based(struct kunit *test)
+{
+ struct clk_fractional_divider *fd;
+ struct clk_hw *hw;
+ unsigned long rate, parent_rate, m, n, max_n;
+
+ fd = kunit_kzalloc(test, sizeof(*fd), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_NULL(test, fd);
+
+ fd->flags = CLK_FRAC_DIVIDER_ZERO_BASED;
+ fd->mwidth = 3;
+ fd->nwidth = 3;
+ max_n = 8;
+
+ hw = &fd->hw;
+
+ rate = 240000000;
+ parent_rate = (max_n + 1) * rate; /* so that it exceeds the maximum divisor */
+
+ clk_fractional_divider_general_approximation(hw, rate, &parent_rate, &m, &n);
+ KUNIT_EXPECT_EQ(test, parent_rate, (max_n + 1) * rate); /* parent remains unchanged */
+ KUNIT_EXPECT_EQ(test, m, 1);
+ KUNIT_EXPECT_EQ(test, n, max_n);
+}
+
+/*
+ * Test the maximum numerator case for zero based fd clock.
+ *
+ * Expect the highest possible numerator to be used in order to get as close as possible to the
+ * requested rate.
+ */
+static void clk_fd_test_approximation_max_numerator_zero_based(struct kunit *test)
+{
+ struct clk_fractional_divider *fd;
+ struct clk_hw *hw;
+ unsigned long rate, parent_rate, m, n, max_m;
+
+ fd = kunit_kzalloc(test, sizeof(*fd), GFP_KERNEL);
+ KUNIT_ASSERT_NOT_NULL(test, fd);
+
+ fd->flags = CLK_FRAC_DIVIDER_ZERO_BASED;
+ fd->mwidth = 3;
+ max_m = 8;
+ fd->nwidth = 3;
+
+ hw = &fd->hw;
+
+ rate = 240000000;
+ parent_rate = rate / (max_m + 1); /* so that it exceeds the maximum numerator */
+
+ clk_fractional_divider_general_approximation(hw, rate, &parent_rate, &m, &n);
+ KUNIT_EXPECT_EQ(test, parent_rate, rate / (max_m + 1)); /* parent remains unchanged */
+ KUNIT_EXPECT_EQ(test, m, max_m);
+ KUNIT_EXPECT_EQ(test, n, 1);
+}
+
+static struct kunit_case clk_fd_test_cases[] = {
+ KUNIT_CASE(clk_fd_test_approximation_max_denominator),
+ KUNIT_CASE(clk_fd_test_approximation_max_numerator),
+ KUNIT_CASE(clk_fd_test_approximation_max_denominator_zero_based),
+ KUNIT_CASE(clk_fd_test_approximation_max_numerator_zero_based),
+ {}
+};
+
+/*
+ * Test suite for a fractional divider clock.
+ */
+static struct kunit_suite clk_fd_test_suite = {
+ .name = "clk-fd-test",
+ .test_cases = clk_fd_test_cases,
+};
+
+kunit_test_suites(
+ &clk_fd_test_suite
+);
+MODULE_LICENSE("GPL");