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>
diff --git a/drivers/clk/clk_fixed_factor.c b/drivers/clk/clk_fixed_factor.c
new file mode 100644
index 0000000..5fa20a8
--- /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,
+};