sh: SH7722 clock framework support.

This adds support for the SH7722 (MobileR) to the clock framework.

Signed-off-by: dmitry pervushin <dimka@nomadgs.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

Documentation/sh/clk.txt

@@ -0,0 +1,32 @@
+Clock framework on SuperH architecture
+
+The framework on SH extends existing API by the function clk_set_rate_ex,
+which prototype is as follows:
+
+    clk_set_rate_ex (struct clk *clk, unsigned long rate, int algo_id)
+
+The algo_id parameter is used to specify algorithm used to recalculate clocks,
+adjanced to clock, specified as first argument. It is assumed that algo_id==0
+means no changes to adjanced clock
+
+Internally, the clk_set_rate_ex forwards request to clk->ops->set_rate method,
+if it is present in ops structure. The method should set the clock rate and adjust
+all needed clocks according to the passed algo_id.
+Exact values for algo_id are machine-dependend. For the sh7722, the following
+values are defined:
+
+	NO_CHANGE	= 0,
+	IUS_N1_N1,	/* I:U = N:1, U:Sh = N:1 */
+	IUS_322,	/* I:U:Sh = 3:2:2	 */
+	IUS_522,	/* I:U:Sh = 5:2:2 	 */
+	IUS_N11,	/* I:U:Sh = N:1:1	 */
+	SB_N1,		/* Sh:B = N:1		 */
+	SB3_N1,		/* Sh:B3 = N:1		 */
+	SB3_32,		/* Sh:B3 = 3:2		 */
+	SB3_43,		/* Sh:B3 = 4:3		 */
+	SB3_54,		/* Sh:B3 = 5:4		 */
+	BP_N1,		/* B:P	 = N:1		 */
+	IP_N1		/* I:P	 = N:1		 */
+
+Each of these constants means relation between clocks that can be set via the FRQCR
+register

arch/sh/kernel/cpu/clock.c

@@ -98,13 +98,14 @@ int __clk_enable(struct clk *clk)
 		if (clk->ops && clk->ops->init)
 			clk->ops->init(clk);
 
+	kref_get(&clk->kref);
+
 	if (clk->flags & CLK_ALWAYS_ENABLED)
 		return 0;
 
 	if (likely(clk->ops && clk->ops->enable))
 		clk->ops->enable(clk);
 
-	kref_get(&clk->kref);
 	return 0;
 }
 
@@ -127,10 +128,15 @@ static void clk_kref_release(struct kref *kref)
 
 void __clk_disable(struct clk *clk)
 {
+	int count = kref_put(&clk->kref, clk_kref_release);
+
 	if (clk->flags & CLK_ALWAYS_ENABLED)
 		return;
 
-	kref_put(&clk->kref, clk_kref_release);
+	if (!count) {	/* count reaches zero, disable the clock */
+		if (likely(clk->ops && clk->ops->disable))
+			clk->ops->disable(clk);
+	}
 }
 
 void clk_disable(struct clk *clk)
@@ -151,6 +157,15 @@ int clk_register(struct clk *clk)
 
 	mutex_unlock(&clock_list_sem);
 
+	if (clk->flags & CLK_ALWAYS_ENABLED) {
+		pr_debug( "Clock '%s' is ALWAYS_ENABLED\n", clk->name);
+		if (clk->ops && clk->ops->init)
+			clk->ops->init(clk);
+		if (clk->ops && clk->ops->enable)
+			clk->ops->enable(clk);
+		pr_debug( "Enabled.");
+	}
+
 	return 0;
 }
 
@@ -167,6 +182,11 @@ inline unsigned long clk_get_rate(struct clk *clk)
 }
 
 int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	return clk_set_rate_ex(clk, rate, 0);
+}
+
+int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id)
 {
 	int ret = -EOPNOTSUPP;
 
@@ -174,7 +194,7 @@ int clk_set_rate(struct clk *clk, unsigned long rate)
 		unsigned long flags;
 
 		spin_lock_irqsave(&clock_lock, flags);
-		ret = clk->ops->set_rate(clk, rate);
+		ret = clk->ops->set_rate(clk, rate, algo_id);
 		spin_unlock_irqrestore(&clock_lock, flags);
 	}
 
@@ -256,7 +276,6 @@ int __init clk_init(void)
 
 		arch_init_clk_ops(&clk->ops, i);
 		ret |= clk_register(clk);
-		clk_enable(clk);
 	}
 
 	/* Kick the child clocks.. */
@@ -298,3 +317,4 @@ EXPORT_SYMBOL_GPL(__clk_disable);
 EXPORT_SYMBOL_GPL(clk_get_rate);
 EXPORT_SYMBOL_GPL(clk_set_rate);
 EXPORT_SYMBOL_GPL(clk_recalc_rate);
+EXPORT_SYMBOL_GPL(clk_set_rate_ex);

arch/sh/kernel/cpu/sh4/clock-sh4-202.c

@@ -82,7 +82,8 @@ static void shoc_clk_init(struct clk *clk)
 	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)
+		if (clk->ops->set_rate(clk, clk->parent->rate /
+						divisor, 0) == 0)
 			break;
 	}
 

arch/sh/kernel/cpu/sh4a/Makefile

@@ -16,6 +16,6 @@ clock-$(CONFIG_CPU_SUBTYPE_SH7770)	:= clock-sh7770.o
 clock-$(CONFIG_CPU_SUBTYPE_SH7780)	:= clock-sh7780.o
 clock-$(CONFIG_CPU_SUBTYPE_SH7785)	:= clock-sh7785.o
 clock-$(CONFIG_CPU_SUBTYPE_SH7343)	:= clock-sh7343.o
-clock-$(CONFIG_CPU_SUBTYPE_SH7722)	:= clock-sh7343.o
+clock-$(CONFIG_CPU_SUBTYPE_SH7722)	:= clock-sh7722.o
 
 obj-y	+= $(clock-y)

include/asm-sh/clock.h

@@ -13,7 +13,7 @@ struct clk_ops {
 	void (*enable)(struct clk *clk);
 	void (*disable)(struct clk *clk);
 	void (*recalc)(struct clk *clk);
-	int (*set_rate)(struct clk *clk, unsigned long rate);
+	int (*set_rate)(struct clk *clk, unsigned long rate, int algo_id);
 };
 
 struct clk {
@@ -50,4 +50,34 @@ void clk_unregister(struct clk *);
 
 int show_clocks(struct seq_file *m);
 
+/* the exported API, in addition to clk_set_rate */
+/**
+ * clk_set_rate_ex - set the clock rate for a clock source, with additional parameter
+ * @clk: clock source
+ * @rate: desired clock rate in Hz
+ * @algo_id: algorithm id to be passed down to ops->set_rate
+ *
+ * Returns success (0) or negative errno.
+ */
+int clk_set_rate_ex(struct clk *clk, unsigned long rate, int algo_id);
+
+enum clk_sh_algo_id {
+	NO_CHANGE = 0,
+
+	IUS_N1_N1,
+	IUS_322,
+	IUS_522,
+	IUS_N11,
+
+	SB_N1,
+
+	SB3_N1,
+	SB3_32,
+	SB3_43,
+	SB3_54,
+
+	BP_N1,
+
+	IP_N1,
+};
 #endif /* __ASM_SH_CLOCK_H */

include/asm-sh/cpu-sh4/freq.h

@@ -12,6 +12,10 @@
 
 #if defined(CONFIG_CPU_SUBTYPE_SH73180) || defined(CONFIG_CPU_SUBTYPE_SH7722)
 #define FRQCR		        0xa4150000
+#define VCLKCR			0xa4150004
+#define SCLKACR			0xa4150008
+#define SCLKBCR			0xa415000c
+#define IrDACLKCR		0xa4150010
 #elif defined(CONFIG_CPU_SUBTYPE_SH7780)
 #define	FRQCR			0xffc80000
 #elif defined(CONFIG_CPU_SUBTYPE_SH7785)