clk: sandbox: Add sandbox test code for Common Clock Framework [CCF]

This patch provides code to implement the CCF clock tree in sandbox. It
uses all the introduced primitives; some generic ones are reused, some
sandbox specific were developed.

In that way (after introducing the real CCF tree in sandbox) the recently
added to clk-uclass.c: clk_get_by_id() and clk_get_parent_rate() are tested
in their natural work environment.

Usage (sandbox_defconfig and sandbox_flattree_defconfig):
./u-boot --fdt arch/sandbox/dts/test.dtb --command "ut dm clk_ccf"

Signed-off-by: Lukasz Majewski <lukma@denx.de>
diff --git a/test/dm/clk_ccf.c b/test/dm/clk_ccf.c
new file mode 100644
index 0000000..8d39759
--- /dev/null
+++ b/test/dm/clk_ccf.c
@@ -0,0 +1,62 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019
+ * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
+ */
+
+#include <common.h>
+#include <clk.h>
+#include <dm.h>
+#include <asm/clk.h>
+#include <dm/test.h>
+#include <dm/uclass.h>
+#include <linux/err.h>
+#include <test/ut.h>
+#include <sandbox-clk.h>
+
+/* Tests for Common Clock Framework driver */
+static int dm_test_clk_ccf(struct unit_test_state *uts)
+{
+	struct clk *clk, *pclk;
+	struct udevice *dev;
+	long long rate;
+	int ret;
+
+	/* Get the device using the clk device */
+	ut_assertok(uclass_get_device_by_name(UCLASS_CLK, "clk-ccf", &dev));
+
+	/* Test for clk_get_by_id() */
+	ret = clk_get_by_id(SANDBOX_CLK_ECSPI_ROOT, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("ecspi_root", clk->dev->name);
+
+	/* Test for clk_get_parent_rate() */
+	ret = clk_get_by_id(SANDBOX_CLK_ECSPI1, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("ecspi1", clk->dev->name);
+
+	rate = clk_get_parent_rate(clk);
+	ut_asserteq(rate, 20000000);
+
+	/* Test the mux of CCF */
+	ret = clk_get_by_id(SANDBOX_CLK_USDHC1_SEL, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("usdhc1_sel", clk->dev->name);
+
+	rate = clk_get_parent_rate(clk);
+	ut_asserteq(rate, 60000000);
+
+	ret = clk_get_by_id(SANDBOX_CLK_USDHC2_SEL, &clk);
+	ut_assertok(ret);
+	ut_asserteq_str("usdhc2_sel", clk->dev->name);
+
+	rate = clk_get_parent_rate(clk);
+	ut_asserteq(rate, 80000000);
+
+	pclk = clk_get_parent(clk);
+	ut_asserteq_str("pll3_80m", pclk->dev->name);
+
+	return 1;
+}
+
+DM_TEST(dm_test_clk_ccf, DM_TESTF_SCAN_FDT);