[PATCH] sh: Simplistic clock framework

This adds a relatively simplistic clock framework for sh.  The initial goal
behind this is to clean up the arch/sh/kernel/time.c mess and to get the CPU
subtype-specific frequency setting and calculation code moved somewhere more
sensible.

This only deals with the core clocks at the moment, though it's trivial for
other drivers to define their own clocks as desired.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 126 insertions, 0 deletions

diff --git a/arch/sh/kernel/cpu/sh4/clock-sh7780.c b/arch/sh/kernel/cpu/sh4/clock-sh7780.c
new file mode 100644
index 0000000..93ad367
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/clock-sh7780.c
@@ -0,0 +1,126 @@
+/*
+ * arch/sh/kernel/cpu/sh4/clock-sh7780.c
+ *
+ * SH7780 support for the clock framework
+ *
+ *  Copyright (C) 2005  Paul Mundt
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file "COPYING" in the main directory of this archive
+ * for more details.
+ */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <asm/clock.h>
+#include <asm/freq.h>
+#include <asm/io.h>
+
+static int ifc_divisors[] = { 2, 4 };
+static int bfc_divisors[] = { 1, 1, 1, 8, 12, 16, 24, 1 };
+static int pfc_divisors[] = { 1, 24, 24, 1 };
+static int cfc_divisors[] = { 1, 1, 4, 1, 6, 1, 1, 1 };
+
+static void master_clk_init(struct clk *clk)
+{
+	clk->rate *= pfc_divisors[ctrl_inl(FRQCR) & 0x0003];
+}
+
+static struct clk_ops sh7780_master_clk_ops = {
+	.init		= master_clk_init,
+};
+
+static void module_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inl(FRQCR) & 0x0003);
+	clk->rate = clk->parent->rate / pfc_divisors[idx];
+}
+
+static struct clk_ops sh7780_module_clk_ops = {
+	.recalc		= module_clk_recalc,
+};
+
+static void bus_clk_recalc(struct clk *clk)
+{
+	int idx = ((ctrl_inl(FRQCR) >> 16) & 0x0007);
+	clk->rate = clk->parent->rate / bfc_divisors[idx];
+}
+
+static struct clk_ops sh7780_bus_clk_ops = {
+	.recalc		= bus_clk_recalc,
+};
+
+static void cpu_clk_recalc(struct clk *clk)
+{
+	int idx = ((ctrl_inl(FRQCR) >> 24) & 0x0001);
+	clk->rate = clk->parent->rate / ifc_divisors[idx];
+}
+
+static struct clk_ops sh7780_cpu_clk_ops = {
+	.recalc		= cpu_clk_recalc,
+};
+
+static struct clk_ops *sh7780_clk_ops[] = {
+	&sh7780_master_clk_ops,
+	&sh7780_module_clk_ops,
+	&sh7780_bus_clk_ops,
+	&sh7780_cpu_clk_ops,
+};
+
+void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
+{
+	if (idx < ARRAY_SIZE(sh7780_clk_ops))
+		*ops = sh7780_clk_ops[idx];
+}
+
+static void shyway_clk_recalc(struct clk *clk)
+{
+	int idx = ((ctrl_inl(FRQCR) >> 20) & 0x0007);
+	clk->rate = clk->parent->rate / cfc_divisors[idx];
+}
+
+static struct clk_ops sh7780_shyway_clk_ops = {
+	.recalc		= shyway_clk_recalc,
+};
+
+static struct clk sh7780_shyway_clk = {
+	.name		= "shyway_clk",
+	.flags		= CLK_ALWAYS_ENABLED,
+	.ops		= &sh7780_shyway_clk_ops,
+};
+
+/*
+ * Additional SH7780-specific on-chip clocks that aren't already part of the
+ * clock framework
+ */
+static struct clk *sh7780_onchip_clocks[] = {
+	&sh7780_shyway_clk,
+};
+
+static int __init sh7780_clk_init(void)
+{
+	struct clk *clk = clk_get("master_clk");
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sh7780_onchip_clocks); i++) {
+		struct clk *clkp = sh7780_onchip_clocks[i];
+
+		clkp->parent = clk;
+		clk_register(clkp);
+		clk_enable(clkp);
+	}
+
+	/*
+	 * Now that we have the rest of the clocks registered, we need to
+	 * force the parent clock to propagate so that these clocks will
+	 * automatically figure out their rate. We cheat by handing the
+	 * parent clock its current rate and forcing child propagation.
+	 */
+	clk_set_rate(clk, clk_get_rate(clk));
+
+	clk_put(clk);
+
+	return 0;
+}
+
+arch_initcall(sh7780_clk_init);
+