clk: Add fixed-factor clock driver

This patch adds fixed-factor clock driver which derives clock
rate by dividing (div) and multiplying (mult) fixed factors
to a parent clock.

Signed-off-by: Atish Patra <atish.patra@wdc.com>
Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

2 files changed, 77 insertions, 1 deletions

diff --git a/drivers/clk/Makefile b/drivers/clk/Makefile
index de3d60ed05..1d9d725cae 100644
--- a/drivers/clk/Makefile
+++ b/drivers/clk/Makefile
@@ -4,7 +4,9 @@
 # Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 #
 
-obj-$(CONFIG_$(SPL_TPL_)CLK) += clk-uclass.o clk_fixed_rate.o
+obj-$(CONFIG_$(SPL_TPL_)CLK) += clk-uclass.o
+obj-$(CONFIG_$(SPL_TPL_)CLK) += clk_fixed_rate.o
+obj-$(CONFIG_$(SPL_TPL_)CLK) += clk_fixed_factor.o
 
 obj-y += imx/
 obj-y += tegra/
diff --git a/drivers/clk/clk_fixed_factor.c b/drivers/clk/clk_fixed_factor.c
new file mode 100644
index 0000000000..5fa20a84db
--- /dev/null
+++ b/drivers/clk/clk_fixed_factor.c
@@ -0,0 +1,74 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2019 Western Digital Corporation or its affiliates.
+ *
+ * Author: Anup Patel <anup.patel@wdc.com>
+ */
+
+#include <common.h>
+#include <clk-uclass.h>
+#include <div64.h>
+#include <dm.h>
+
+struct clk_fixed_factor {
+	struct clk parent;
+	unsigned int div;
+	unsigned int mult;
+};
+
+#define to_clk_fixed_factor(dev)	\
+	((struct clk_fixed_factor *)dev_get_platdata(dev))
+
+static ulong clk_fixed_factor_get_rate(struct clk *clk)
+{
+	uint64_t rate;
+	struct clk_fixed_factor *ff = to_clk_fixed_factor(clk->dev);
+
+	if (clk->id != 0)
+		return -EINVAL;
+
+	rate = clk_get_rate(&ff->parent);
+	if (IS_ERR_VALUE(rate))
+		return rate;
+
+	do_div(rate, ff->div);
+
+	return rate * ff->mult;
+}
+
+const struct clk_ops clk_fixed_factor_ops = {
+	.get_rate = clk_fixed_factor_get_rate,
+};
+
+static int clk_fixed_factor_ofdata_to_platdata(struct udevice *dev)
+{
+#if !CONFIG_IS_ENABLED(OF_PLATDATA)
+	int err;
+	struct clk_fixed_factor *ff = to_clk_fixed_factor(dev);
+
+	err = clk_get_by_index(dev, 0, &ff->parent);
+	if (err)
+		return err;
+
+	ff->div = dev_read_u32_default(dev, "clock-div", 1);
+	ff->mult = dev_read_u32_default(dev, "clock-mult", 1);
+#endif
+
+	return 0;
+}
+
+static const struct udevice_id clk_fixed_factor_match[] = {
+	{
+		.compatible = "fixed-factor-clock",
+	},
+	{ /* sentinel */ }
+};
+
+U_BOOT_DRIVER(clk_fixed_factor) = {
+	.name = "fixed_factor_clock",
+	.id = UCLASS_CLK,
+	.of_match = clk_fixed_factor_match,
+	.ofdata_to_platdata = clk_fixed_factor_ofdata_to_platdata,
+	.platdata_auto_alloc_size = sizeof(struct clk_fixed_factor),
+	.ops = &clk_fixed_factor_ops,
+};