sh: Only provide a PCLK definition for legacy CPG CPUs.

As CPUs are migrated over to more fully-featured clock frameworks of
their own and off of the legacy CPG code, they no longer have any real
need for defining the PCLK value. The PCLK define in itself is already
fairly misleading, as many boards get their input clocks from different
sources, making this value fairly arbitrary anyways.

Outside of the legacy CPG clock framework, the only place where this
value is used is for deriving CLOCK_TICK_RATE, which we set back to the
legacy PIT value that it was before the PCLK definitions were added in
the first place.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/Kconfig

@@ -540,14 +540,16 @@ config SH_TIMER_MTU2
 
 config SH_PCLK_FREQ
 	int "Peripheral clock frequency (in Hz)"
-	default "27000000" if CPU_SUBTYPE_SH7343
+	depends on SH_CLK_CPG_LEGACY
 	default "31250000" if CPU_SUBTYPE_SH7619
-	default "32000000" if CPU_SUBTYPE_SH7722
-	default "33333333" if CPU_SUBTYPE_SH7770 || CPU_SUBTYPE_SH7723 || \
-			      CPU_SUBTYPE_SH7760 || CPU_SUBTYPE_SH7705 || \
-			      CPU_SUBTYPE_SH7203 || CPU_SUBTYPE_SH7206 || \
-			      CPU_SUBTYPE_SH7263 || CPU_SUBTYPE_MXG    || \
-			      CPU_SUBTYPE_SH7786 || CPU_SUBTYPE_SH7724
+	default "33333333" if CPU_SUBTYPE_SH7770 || \
+			      CPU_SUBTYPE_SH7760 || \
+			      CPU_SUBTYPE_SH7705 || \
+			      CPU_SUBTYPE_SH7203 || \
+			      CPU_SUBTYPE_SH7206 || \
+			      CPU_SUBTYPE_SH7263 || \
+			      CPU_SUBTYPE_MXG    || \
+			      CPU_SUBTYPE_SH7786
 	default "60000000" if CPU_SUBTYPE_SH7751 || CPU_SUBTYPE_SH7751R
 	default "66000000" if CPU_SUBTYPE_SH4_202
 	default "50000000"

arch/sh/include/asm/timex.h

@@ -6,7 +6,17 @@
 #ifndef __ASM_SH_TIMEX_H
 #define __ASM_SH_TIMEX_H
 
+/*
+ * Only parts using the legacy CPG code for their clock framework
+ * implementation need to define their own Pclk value. If provided, this
+ * can be used for accurately setting CLOCK_TICK_RATE, otherwise we
+ * simply fall back on the i8253 PIT value.
+ */
+#ifdef CONFIG_SH_PCLK_FREQ
 #define CLOCK_TICK_RATE		(CONFIG_SH_PCLK_FREQ / 4) /* Underlying HZ */
+#else
+#define CLOCK_TICK_RATE		1193180
+#endif
 
 #include <asm-generic/timex.h>