1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/clk/mmp/clk-pll.c b/drivers/clk/mmp/clk-pll.c
new file mode 100644
index 000000000000..7077be293871
--- /dev/null
+++ b/drivers/clk/mmp/clk-pll.c
@@ -0,0 +1,139 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * MMP PLL clock rate calculation
+ *
+ * Copyright (C) 2020 Lubomir Rintel <lkundrak@v3.sk>
+ */
+
+#include <linux/clk-provider.h>
+#include <linux/slab.h>
+#include <linux/io.h>
+
+#include "clk.h"
+
+#define to_clk_mmp_pll(hw)	container_of(hw, struct mmp_clk_pll, hw)
+
+struct mmp_clk_pll {
+	struct clk_hw hw;
+	unsigned long default_rate;
+	void __iomem *enable_reg;
+	u32 enable;
+	void __iomem *reg;
+	u8 shift;
+
+	unsigned long input_rate;
+	void __iomem *postdiv_reg;
+	u8 postdiv_shift;
+};
+
+static int mmp_clk_pll_is_enabled(struct clk_hw *hw)
+{
+	struct mmp_clk_pll *pll = to_clk_mmp_pll(hw);
+	u32 val;
+
+	val = readl_relaxed(pll->enable_reg);
+	if ((val & pll->enable) == pll->enable)
+		return 1;
+
+	/* Some PLLs, if not software controlled, output default clock. */
+	if (pll->default_rate > 0)
+		return 1;
+
+	return 0;
+}
+
+static unsigned long mmp_clk_pll_recalc_rate(struct clk_hw *hw,
+					unsigned long parent_rate)
+{
+	struct mmp_clk_pll *pll = to_clk_mmp_pll(hw);
+	u32 fbdiv, refdiv, postdiv;
+	u64 rate;
+	u32 val;
+
+	val = readl_relaxed(pll->enable_reg);
+	if ((val & pll->enable) != pll->enable)
+		return pll->default_rate;
+
+	if (pll->reg) {
+		val = readl_relaxed(pll->reg);
+		fbdiv = (val >> pll->shift) & 0x1ff;
+		refdiv = (val >> (pll->shift + 9)) & 0x1f;
+	} else {
+		fbdiv = 2;
+		refdiv = 1;
+	}
+
+	if (pll->postdiv_reg) {
+		/* MMP3 clock rate calculation */
+		static const u8 postdivs[] = {2, 3, 4, 5, 6, 8, 10, 12, 16};
+
+		val = readl_relaxed(pll->postdiv_reg);
+		postdiv = (val >> pll->postdiv_shift) & 0x7;
+
+		rate = pll->input_rate;
+		rate *= 2 * fbdiv;
+		do_div(rate, refdiv);
+		do_div(rate, postdivs[postdiv]);
+	} else {
+		/* MMP2 clock rate calculation */
+		if (refdiv == 3) {
+			rate = 19200000;
+		} else if (refdiv == 4) {
+			rate = 26000000;
+		} else {
+			pr_err("bad refdiv: %d (0x%08x)\n", refdiv, val);
+			return 0;
+		}
+
+		rate *= fbdiv + 2;
+		do_div(rate, refdiv + 2);
+	}
+
+	return (unsigned long)rate;
+}
+
+static const struct clk_ops mmp_clk_pll_ops = {
+	.is_enabled = mmp_clk_pll_is_enabled,
+	.recalc_rate = mmp_clk_pll_recalc_rate,
+};
+
+struct clk *mmp_clk_register_pll(char *name,
+			unsigned long default_rate,
+			void __iomem *enable_reg, u32 enable,
+			void __iomem *reg, u8 shift,
+			unsigned long input_rate,
+			void __iomem *postdiv_reg, u8 postdiv_shift)
+{
+	struct mmp_clk_pll *pll;
+	struct clk *clk;
+	struct clk_init_data init;
+
+	pll = kzalloc(sizeof(*pll), GFP_KERNEL);
+	if (!pll)
+		return ERR_PTR(-ENOMEM);
+
+	init.name = name;
+	init.ops = &mmp_clk_pll_ops;
+	init.flags = 0;
+	init.parent_names = NULL;
+	init.num_parents = 0;
+
+	pll->default_rate = default_rate;
+	pll->enable_reg = enable_reg;
+	pll->enable = enable;
+	pll->reg = reg;
+	pll->shift = shift;
+
+	pll->input_rate = input_rate;
+	pll->postdiv_reg = postdiv_reg;
+	pll->postdiv_shift = postdiv_shift;
+
+	pll->hw.init = &init;
+
+	clk = clk_register(NULL, &pll->hw);
+
+	if (IS_ERR(clk))
+		kfree(pll);
+
+	return clk;
+}