clk: Add K210 pll support

This pll code is primarily based on the code from the kendryte standalone
sdk in lib/drivers/sysctl.c. k210_pll_calc_config is roughly analogous to
the algorithm used to set the pll frequency, but it has been completely
rewritten to be fixed-point based.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
CC: Lukasz Majewski <lukma@denx.de>

2 files changed, 73 insertions, 0 deletions

diff --git a/include/kendryte/pll.h b/include/kendryte/pll.h
new file mode 100644
index 0000000000..c8e3200799
--- /dev/null
+++ b/include/kendryte/pll.h
@@ -0,0 +1,57 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2019-20 Sean Anderson <seanga2@gmail.com>
+ */
+#ifndef K210_PLL_H
+#define K210_PLL_H
+
+#include <clk.h>
+#include <test/export.h>
+
+#define K210_PLL_CLKR GENMASK(3, 0)
+#define K210_PLL_CLKF GENMASK(9, 4)
+#define K210_PLL_CLKOD GENMASK(13, 10) /* Output Divider */
+#define K210_PLL_BWADJ GENMASK(19, 14) /* BandWidth Adjust */
+#define K210_PLL_RESET BIT(20)
+#define K210_PLL_PWRD BIT(21) /* PoWeReD */
+#define K210_PLL_INTFB BIT(22) /* Internal FeedBack */
+#define K210_PLL_BYPASS BIT(23)
+#define K210_PLL_TEST BIT(24)
+#define K210_PLL_EN BIT(25)
+#define K210_PLL_TEST_EN BIT(26)
+
+#define K210_PLL_LOCK 0
+#define K210_PLL_CLEAR_SLIP 2
+#define K210_PLL_TEST_OUT 3
+
+struct k210_pll {
+	struct clk clk;
+	void __iomem *reg; /* Base PLL register */
+	void __iomem *lock; /* Common PLL lock register */
+	u8 shift; /* Offset of bits in lock register */
+	u8 width; /* Width of lock bits to test against */
+};
+
+#define to_k210_pll(_clk) container_of(_clk, struct k210_pll, clk)
+
+struct k210_pll_config {
+	u8 r;
+	u8 f;
+	u8 od;
+};
+
+#ifdef CONFIG_UNIT_TEST
+TEST_STATIC int k210_pll_calc_config(u32 rate, u32 rate_in,
+				     struct k210_pll_config *best);
+#define nop()
+#endif
+
+extern const struct clk_ops k210_pll_ops;
+
+struct clk *k210_register_pll_struct(const char *name, const char *parent_name,
+				     struct k210_pll *pll);
+struct clk *k210_register_pll(const char *name, const char *parent_name,
+			      void __iomem *reg, void __iomem *lock, u8 shift,
+			      u8 width);
+
+#endif /* K210_PLL_H */
diff --git a/include/test/export.h b/include/test/export.h
new file mode 100644
index 0000000000..afc755a8ff
--- /dev/null
+++ b/include/test/export.h
@@ -0,0 +1,16 @@
+/* SPDX-License-Identifier: GPL-2.0+ */
+/*
+ * Copyright (C) 2020 Sean Anderson <seanga2@gmail.com>
+ */
+
+#ifndef TEST_EXPORT_H
+#define TEST_EXPORT_H
+
+/* Declare something static, unless we are doing unit tests */
+#ifdef CONFIG_UNIT_TEST
+#define TEST_STATIC
+#else
+#define TEST_STATIC static
+#endif
+
+#endif /* TEST_EXPORT_H */