[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>

arch/sh/kernel/cpu/sh3/clock-sh7705.c

@@ -0,0 +1,84 @@
+/*
+ * arch/sh/kernel/cpu/sh3/clock-sh7705.c
+ *
+ * SH7705 support for the clock framework
+ *
+ *  Copyright (C) 2005  Paul Mundt
+ *
+ * FRQCR parsing hacked out of arch/sh/kernel/time.c
+ *
+ *  Copyright (C) 1999  Tetsuya Okada & Niibe Yutaka
+ *  Copyright (C) 2000  Philipp Rumpf <prumpf@tux.org>
+ *  Copyright (C) 2002, 2003, 2004  Paul Mundt
+ *  Copyright (C) 2002  M. R. Brown  <mrbrown@linux-sh.org>
+ *
+ * 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>
+
+/*
+ * SH7705 uses the same divisors as the generic SH-3 case, it's just the
+ * FRQCR layout that is a bit different..
+ */
+static int stc_multipliers[] = { 1, 2, 3, 4, 6, 1, 1, 1 };
+static int ifc_divisors[]    = { 1, 2, 3, 4, 1, 1, 1, 1 };
+static int pfc_divisors[]    = { 1, 2, 3, 4, 6, 1, 1, 1 };
+
+static void master_clk_init(struct clk *clk)
+{
+	clk->rate *= pfc_divisors[ctrl_inw(FRQCR) & 0x0003];
+}
+
+static struct clk_ops sh7705_master_clk_ops = {
+	.init		= master_clk_init,
+};
+
+static void module_clk_recalc(struct clk *clk)
+{
+	int idx = ctrl_inw(FRQCR) & 0x0003;
+	clk->rate = clk->parent->rate / pfc_divisors[idx];
+}
+
+static struct clk_ops sh7705_module_clk_ops = {
+	.recalc		= module_clk_recalc,
+};
+
+static void bus_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inw(FRQCR) & 0x0300) >> 8;
+	clk->rate = clk->parent->rate / stc_multipliers[idx];
+}
+
+static struct clk_ops sh7705_bus_clk_ops = {
+	.recalc		= bus_clk_recalc,
+};
+
+static void cpu_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inw(FRQCR) & 0x0030) >> 4;
+	clk->rate = clk->parent->rate / ifc_divisors[idx];
+}
+
+static struct clk_ops sh7705_cpu_clk_ops = {
+	.recalc		= cpu_clk_recalc,
+};
+
+static struct clk_ops *sh7705_clk_ops[] = {
+	&sh7705_master_clk_ops,
+	&sh7705_module_clk_ops,
+	&sh7705_bus_clk_ops,
+	&sh7705_cpu_clk_ops,
+};
+
+void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
+{
+	if (idx < ARRAY_SIZE(sh7705_clk_ops))
+		*ops = sh7705_clk_ops[idx];
+}
+