[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>

6 files changed, 549 insertions, 1 deletions

diff --git a/arch/sh/kernel/cpu/sh4/Makefile b/arch/sh/kernel/cpu/sh4/Makefile
index ead1071eac73..3d5cafc71ae3 100644
--- a/arch/sh/kernel/cpu/sh4/Makefile
+++ b/arch/sh/kernel/cpu/sh4/Makefile
@@ -5,6 +5,15 @@
 obj-y	:= ex.o probe.o
 
 obj-$(CONFIG_SH_FPU)                    += fpu.o
-obj-$(CONFIG_CPU_SUBTYPE_ST40STB1)	+= irq_intc2.o
 obj-$(CONFIG_SH_STORE_QUEUES)		+= sq.o
 
+# Primary on-chip clocks (common)
+clock-$(CONFIG_CPU_SH4)			:= clock-sh4.o
+clock-$(CONFIG_CPU_SUBTYPE_SH73180)	:= clock-sh73180.o
+clock-$(CONFIG_CPU_SUBTYPE_SH7770)	:= clock-sh7770.o
+clock-$(CONFIG_CPU_SUBTYPE_SH7780)	:= clock-sh7780.o
+
+# Additional clocks by subtype
+clock-$(CONFIG_CPU_SUBTYPE_SH4_202)	+= clock-sh4-202.o
+
+obj-y	+= $(clock-y)
diff --git a/arch/sh/kernel/cpu/sh4/clock-sh4-202.c b/arch/sh/kernel/cpu/sh4/clock-sh4-202.c
new file mode 100644
index 000000000000..bfdf5fe8d948
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/clock-sh4-202.c
@@ -0,0 +1,179 @@
+/*
+ * arch/sh/kernel/cpu/sh4/clock-sh4-202.c
+ *
+ * Additional SH4-202 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 <linux/err.h>
+#include <asm/clock.h>
+#include <asm/freq.h>
+#include <asm/io.h>
+
+#define CPG2_FRQCR3	0xfe0a0018
+
+static int frqcr3_divisors[] = { 1, 2, 3, 4, 6, 8, 16 };
+static int frqcr3_values[]   = { 0, 1, 2, 3, 4, 5, 6  };
+
+static void emi_clk_recalc(struct clk *clk)
+{
+	int idx = ctrl_inl(CPG2_FRQCR3) & 0x0007;
+	clk->rate = clk->parent->rate / frqcr3_divisors[idx];
+}
+
+static inline int frqcr3_lookup(struct clk *clk, unsigned long rate)
+{
+	int divisor = clk->parent->rate / rate;
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(frqcr3_divisors); i++)
+		if (frqcr3_divisors[i] == divisor)
+			return frqcr3_values[i];
+
+	/* Safe fallback */
+	return 5;
+}
+
+static struct clk_ops sh4202_emi_clk_ops = {
+	.recalc		= emi_clk_recalc,
+};
+
+static struct clk sh4202_emi_clk = {
+	.name		= "emi_clk",
+	.flags		= CLK_ALWAYS_ENABLED,
+	.ops		= &sh4202_emi_clk_ops,
+};
+
+static void femi_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inl(CPG2_FRQCR3) >> 3) & 0x0007;
+	clk->rate = clk->parent->rate / frqcr3_divisors[idx];
+}
+
+static struct clk_ops sh4202_femi_clk_ops = {
+	.recalc		= femi_clk_recalc,
+};
+
+static struct clk sh4202_femi_clk = {
+	.name		= "femi_clk",
+	.flags		= CLK_ALWAYS_ENABLED,
+	.ops		= &sh4202_femi_clk_ops,
+};
+
+static void shoc_clk_init(struct clk *clk)
+{
+	int i;
+
+	/*
+	 * For some reason, the shoc_clk seems to be set to some really
+	 * insane value at boot (values outside of the allowable frequency
+	 * range for instance). We deal with this by scaling it back down
+	 * to something sensible just in case.
+	 *
+	 * Start scaling from the high end down until we find something
+	 * that passes rate verification..
+	 */
+	for (i = 0; i < ARRAY_SIZE(frqcr3_divisors); i++) {
+		int divisor = frqcr3_divisors[i];
+
+		if (clk->ops->set_rate(clk, clk->parent->rate / divisor) == 0)
+			break;
+	}
+
+	WARN_ON(i == ARRAY_SIZE(frqcr3_divisors));	/* Undefined clock */
+}
+
+static void shoc_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inl(CPG2_FRQCR3) >> 6) & 0x0007;
+	clk->rate = clk->parent->rate / frqcr3_divisors[idx];
+}
+
+static int shoc_clk_verify_rate(struct clk *clk, unsigned long rate)
+{
+	struct clk *bclk = clk_get("bus_clk");
+	unsigned long bclk_rate = clk_get_rate(bclk);
+
+	clk_put(bclk);
+
+	if (rate > bclk_rate)
+		return 1;
+	if (rate > 66000000)
+		return 1;
+
+	return 0;
+}
+
+static int shoc_clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	unsigned long frqcr3;
+	unsigned int tmp;
+
+	/* Make sure we have something sensible to switch to */
+	if (shoc_clk_verify_rate(clk, rate) != 0)
+		return -EINVAL;
+
+	tmp = frqcr3_lookup(clk, rate);
+
+	frqcr3 = ctrl_inl(CPG2_FRQCR3);
+	frqcr3 &= ~(0x0007 << 6);
+	frqcr3 |= tmp << 6;
+	ctrl_outl(frqcr3, CPG2_FRQCR3);
+
+	clk->rate = clk->parent->rate / frqcr3_divisors[tmp];
+
+	return 0;
+}
+
+static struct clk_ops sh4202_shoc_clk_ops = {
+	.init		= shoc_clk_init,
+	.recalc		= shoc_clk_recalc,
+	.set_rate	= shoc_clk_set_rate,
+};
+
+static struct clk sh4202_shoc_clk = {
+	.name		= "shoc_clk",
+	.flags		= CLK_ALWAYS_ENABLED,
+	.ops		= &sh4202_shoc_clk_ops,
+};
+
+static struct clk *sh4202_onchip_clocks[] = {
+	&sh4202_emi_clk,
+	&sh4202_femi_clk,
+	&sh4202_shoc_clk,
+};
+
+static int __init sh4202_clk_init(void)
+{
+	struct clk *clk = clk_get("master_clk");
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(sh4202_onchip_clocks); i++) {
+		struct clk *clkp = sh4202_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(sh4202_clk_init);
+
diff --git a/arch/sh/kernel/cpu/sh4/clock-sh4.c b/arch/sh/kernel/cpu/sh4/clock-sh4.c
new file mode 100644
index 000000000000..dca9f87a12d6
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/clock-sh4.c
@@ -0,0 +1,80 @@
+/*
+ * arch/sh/kernel/cpu/sh4/clock-sh4.c
+ *
+ * Generic SH-4 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>
+
+static int ifc_divisors[] = { 1, 2, 3, 4, 6, 8, 1, 1 };
+#define bfc_divisors ifc_divisors	/* Same */
+static int pfc_divisors[] = { 2, 3, 4, 6, 8, 2, 2, 2 };
+
+static void master_clk_init(struct clk *clk)
+{
+	clk->rate *= pfc_divisors[ctrl_inw(FRQCR) & 0x0007];
+}
+
+static struct clk_ops sh4_master_clk_ops = {
+	.init		= master_clk_init,
+};
+
+static void module_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inw(FRQCR) & 0x0007);
+	clk->rate = clk->parent->rate / pfc_divisors[idx];
+}
+
+static struct clk_ops sh4_module_clk_ops = {
+	.recalc		= module_clk_recalc,
+};
+
+static void bus_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inw(FRQCR) >> 3) & 0x0007;
+	clk->rate = clk->parent->rate / bfc_divisors[idx];
+}
+
+static struct clk_ops sh4_bus_clk_ops = {
+	.recalc		= bus_clk_recalc,
+};
+
+static void cpu_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inw(FRQCR) >> 6) & 0x0007;
+	clk->rate = clk->parent->rate / ifc_divisors[idx];
+}
+
+static struct clk_ops sh4_cpu_clk_ops = {
+	.recalc		= cpu_clk_recalc,
+};
+
+static struct clk_ops *sh4_clk_ops[] = {
+	&sh4_master_clk_ops,
+	&sh4_module_clk_ops,
+	&sh4_bus_clk_ops,
+	&sh4_cpu_clk_ops,
+};
+
+void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
+{
+	if (idx < ARRAY_SIZE(sh4_clk_ops))
+		*ops = sh4_clk_ops[idx];
+}
+
diff --git a/arch/sh/kernel/cpu/sh4/clock-sh73180.c b/arch/sh/kernel/cpu/sh4/clock-sh73180.c
new file mode 100644
index 000000000000..2fa5cb2ae68d
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/clock-sh73180.c
@@ -0,0 +1,81 @@
+/*
+ * arch/sh/kernel/cpu/sh4/clock-sh73180.c
+ *
+ * SH73180 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>
+
+/*
+ * SH73180 uses a common set of divisors, so this is quite simple..
+ */
+static int divisors[] = { 1, 2, 3, 4, 6, 8, 12, 16 };
+
+static void master_clk_init(struct clk *clk)
+{
+	clk->rate *= divisors[ctrl_inl(FRQCR) & 0x0007];
+}
+
+static struct clk_ops sh73180_master_clk_ops = {
+	.init		= master_clk_init,
+};
+
+static void module_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inl(FRQCR) & 0x0007);
+	clk->rate = clk->parent->rate / divisors[idx];
+}
+
+static struct clk_ops sh73180_module_clk_ops = {
+	.recalc		= module_clk_recalc,
+};
+
+static void bus_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inl(FRQCR) >> 12) & 0x0007;
+	clk->rate = clk->parent->rate / divisors[idx];
+}
+
+static struct clk_ops sh73180_bus_clk_ops = {
+	.recalc		= bus_clk_recalc,
+};
+
+static void cpu_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inl(FRQCR) >> 20) & 0x0007;
+	clk->rate = clk->parent->rate / divisors[idx];
+}
+
+static struct clk_ops sh73180_cpu_clk_ops = {
+	.recalc		= cpu_clk_recalc,
+};
+
+static struct clk_ops *sh73180_clk_ops[] = {
+	&sh73180_master_clk_ops,
+	&sh73180_module_clk_ops,
+	&sh73180_bus_clk_ops,
+	&sh73180_cpu_clk_ops,
+};
+
+void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
+{
+	if (idx < ARRAY_SIZE(sh73180_clk_ops))
+		*ops = sh73180_clk_ops[idx];
+}
+
diff --git a/arch/sh/kernel/cpu/sh4/clock-sh7770.c b/arch/sh/kernel/cpu/sh4/clock-sh7770.c
new file mode 100644
index 000000000000..c8694bac6477
--- /dev/null
+++ b/arch/sh/kernel/cpu/sh4/clock-sh7770.c
@@ -0,0 +1,73 @@
+/*
+ * arch/sh/kernel/cpu/sh4/clock-sh7770.c
+ *
+ * SH7770 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[] = { 1, 1, 1, 1, 1, 1, 1, 1 };
+static int bfc_divisors[] = { 1, 1, 1, 1, 1, 8,12, 1 };
+static int pfc_divisors[] = { 1, 8, 1,10,12,16, 1, 1 };
+
+static void master_clk_init(struct clk *clk)
+{
+	clk->rate *= pfc_divisors[(ctrl_inl(FRQCR) >> 28) & 0x000f];
+}
+
+static struct clk_ops sh7770_master_clk_ops = {
+	.init		= master_clk_init,
+};
+
+static void module_clk_recalc(struct clk *clk)
+{
+	int idx = ((ctrl_inl(FRQCR) >> 28) & 0x000f);
+	clk->rate = clk->parent->rate / pfc_divisors[idx];
+}
+
+static struct clk_ops sh7770_module_clk_ops = {
+	.recalc		= module_clk_recalc,
+};
+
+static void bus_clk_recalc(struct clk *clk)
+{
+	int idx = (ctrl_inl(FRQCR) & 0x000f);
+	clk->rate = clk->parent->rate / bfc_divisors[idx];
+}
+
+static struct clk_ops sh7770_bus_clk_ops = {
+	.recalc		= bus_clk_recalc,
+};
+
+static void cpu_clk_recalc(struct clk *clk)
+{
+	int idx = ((ctrl_inl(FRQCR) >> 24) & 0x000f);
+	clk->rate = clk->parent->rate / ifc_divisors[idx];
+}
+
+static struct clk_ops sh7770_cpu_clk_ops = {
+	.recalc		= cpu_clk_recalc,
+};
+
+static struct clk_ops *sh7770_clk_ops[] = {
+	&sh7770_master_clk_ops,
+	&sh7770_module_clk_ops,
+	&sh7770_bus_clk_ops,
+	&sh7770_cpu_clk_ops,
+};
+
+void __init arch_init_clk_ops(struct clk_ops **ops, int idx)
+{
+	if (idx < ARRAY_SIZE(sh7770_clk_ops))
+		*ops = sh7770_clk_ops[idx];
+}
+
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 000000000000..93ad367342c9
--- /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);
+