h8300: clock driver

Signed-off-by: Yoshinori Sato <ysato@users.sourceforge.jp>

drivers/clk/h8300/clk-div.c

@@ -0,0 +1,53 @@
+/*
+ * H8/300 divide clock driver
+ *
+ * Copyright 2015 Yoshinori Sato <ysato@users.sourceforge.jp>
+ */
+
+#include <linux/clk.h>
+#include <linux/clkdev.h>
+#include <linux/clk-provider.h>
+#include <linux/err.h>
+#include <linux/of.h>
+#include <linux/of_address.h>
+
+static DEFINE_SPINLOCK(clklock);
+
+static void __init h8300_div_clk_setup(struct device_node *node)
+{
+	unsigned int num_parents;
+	struct clk *clk;
+	const char *clk_name = node->name;
+	const char *parent_name;
+	void __iomem *divcr = NULL;
+	int width;
+
+	num_parents = of_clk_get_parent_count(node);
+	if (num_parents < 1) {
+		pr_err("%s: no parent found", clk_name);
+		return;
+	}
+
+	divcr = of_iomap(node, 0);
+	if (divcr == NULL) {
+		pr_err("%s: failed to map divide register", clk_name);
+		goto error;
+	}
+
+	parent_name = of_clk_get_parent_name(node, 0);
+	of_property_read_u32(node, "renesas,width", &width);
+	clk = clk_register_divider(NULL, clk_name, parent_name,
+				   CLK_SET_RATE_GATE, divcr, 0, width,
+				   CLK_DIVIDER_POWER_OF_TWO, &clklock);
+	if (!IS_ERR(clk)) {
+		of_clk_add_provider(node, of_clk_src_simple_get, clk);
+		return;
+	}
+	pr_err("%s: failed to register %s div clock (%ld)\n",
+	       __func__, clk_name, PTR_ERR(clk));
+error:
+	if (divcr)
+		iounmap(divcr);
+}
+
+CLK_OF_DECLARE(h8300_div_clk, "renesas,h8300-div-clock", h8300_div_clk_setup);