1 files changed, 147 insertions, 0 deletions
diff --git a/drivers/clk/clk-divider.c b/drivers/clk/clk-divider.c
new file mode 100644
index 0000000000..3348d97829
--- /dev/null
+++ b/drivers/clk/clk-divider.c
@@ -0,0 +1,147 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2019 DENX Software Engineering
+ * Lukasz Majewski, DENX Software Engineering, lukma@denx.de
+ *
+ * Copyright (C) 2011 Sascha Hauer, Pengutronix <s.hauer@pengutronix.de>
+ * Copyright (C) 2011 Richard Zhao, Linaro <richard.zhao@linaro.org>
+ * Copyright (C) 2011-2012 Mike Turquette, Linaro Ltd <mturquette@linaro.org>
+ *
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <malloc.h>
+#include <clk-uclass.h>
+#include <dm/device.h>
+#include <dm/uclass.h>
+#include <dm/lists.h>
+#include <dm/device-internal.h>
+#include <linux/clk-provider.h>
+#include <div64.h>
+#include <clk.h>
+#include "clk.h"
+
+#define UBOOT_DM_CLK_CCF_DIVIDER "ccf_clk_divider"
+
+static unsigned int _get_table_div(const struct clk_div_table *table,
+				   unsigned int val)
+{
+	const struct clk_div_table *clkt;
+
+	for (clkt = table; clkt->div; clkt++)
+		if (clkt->val == val)
+			return clkt->div;
+	return 0;
+}
+
+static unsigned int _get_div(const struct clk_div_table *table,
+			     unsigned int val, unsigned long flags, u8 width)
+{
+	if (flags & CLK_DIVIDER_ONE_BASED)
+		return val;
+	if (flags & CLK_DIVIDER_POWER_OF_TWO)
+		return 1 << val;
+	if (flags & CLK_DIVIDER_MAX_AT_ZERO)
+		return val ? val : clk_div_mask(width) + 1;
+	if (table)
+		return _get_table_div(table, val);
+	return val + 1;
+}
+
+unsigned long divider_recalc_rate(struct clk *hw, unsigned long parent_rate,
+				  unsigned int val,
+				  const struct clk_div_table *table,
+				  unsigned long flags, unsigned long width)
+{
+	unsigned int div;
+
+	div = _get_div(table, val, flags, width);
+	if (!div) {
+		WARN(!(flags & CLK_DIVIDER_ALLOW_ZERO),
+		     "%s: Zero divisor and CLK_DIVIDER_ALLOW_ZERO not set\n",
+		     clk_hw_get_name(hw));
+		return parent_rate;
+	}
+
+	return DIV_ROUND_UP_ULL((u64)parent_rate, div);
+}
+
+static ulong clk_divider_recalc_rate(struct clk *clk)
+{
+	struct clk_divider *divider =
+		to_clk_divider(dev_get_clk_ptr(clk->dev));
+	unsigned long parent_rate = clk_get_parent_rate(clk);
+	unsigned int val;
+
+	val = readl(divider->reg) >> divider->shift;
+	val &= clk_div_mask(divider->width);
+
+	return divider_recalc_rate(clk, parent_rate, val, divider->table,
+				   divider->flags, divider->width);
+}
+
+const struct clk_ops clk_divider_ops = {
+	.get_rate = clk_divider_recalc_rate,
+};
+
+static struct clk *_register_divider(struct device *dev, const char *name,
+		const char *parent_name, unsigned long flags,
+		void __iomem *reg, u8 shift, u8 width,
+		u8 clk_divider_flags, const struct clk_div_table *table)
+{
+	struct clk_divider *div;
+	struct clk *clk;
+	int ret;
+
+	if (clk_divider_flags & CLK_DIVIDER_HIWORD_MASK) {
+		if (width + shift > 16) {
+			pr_warn("divider value exceeds LOWORD field\n");
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	/* allocate the divider */
+	div = kzalloc(sizeof(*div), GFP_KERNEL);
+	if (!div)
+		return ERR_PTR(-ENOMEM);
+
+	/* struct clk_divider assignments */
+	div->reg = reg;
+	div->shift = shift;
+	div->width = width;
+	div->flags = clk_divider_flags;
+	div->table = table;
+
+	/* register the clock */
+	clk = &div->clk;
+
+	ret = clk_register(clk, UBOOT_DM_CLK_CCF_DIVIDER, name, parent_name);
+	if (ret) {
+		kfree(div);
+		return ERR_PTR(ret);
+	}
+
+	return clk;
+}
+
+struct clk *clk_register_divider(struct device *dev, const char *name,
+		const char *parent_name, unsigned long flags,
+		void __iomem *reg, u8 shift, u8 width,
+		u8 clk_divider_flags)
+{
+	struct clk *clk;
+
+	clk =  _register_divider(dev, name, parent_name, flags, reg, shift,
+				 width, clk_divider_flags, NULL);
+	if (IS_ERR(clk))
+		return ERR_CAST(clk);
+	return clk;
+}
+
+U_BOOT_DRIVER(ccf_clk_divider) = {
+	.name	= UBOOT_DM_CLK_CCF_DIVIDER,
+	.id	= UCLASS_CLK,
+	.ops	= &clk_divider_ops,
+	.flags = DM_FLAG_PRE_RELOC,
+};