sh: CMT clockevent platform driver

SuperH CMT clockevent driver.

Both 16-bit and 32-bit CMT versions are supported, but only 32-bit
is tested. This driver contains support for both clockevents and
clocksources, but no unregistration is supported at this point.

Works fine as clock source and/or event in periodic or oneshot mode.
Tested on sh7722 and sh7723, but should work with any cpu/architecture.

This version is lacking clocksource and early platform driver support
for now - this to minimize the amount of dependencies.

Signed-off-by: Magnus Damm <damm@igel.co.jp>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>

arch/sh/Kconfig

@@ -397,6 +397,14 @@ source "arch/sh/boards/Kconfig"
 
 menu "Timer and clock configuration"
 
+config SH_TIMER_CMT
+	def_bool n
+	prompt "CMT support"
+	select GENERIC_TIME
+	select GENERIC_CLOCKEVENTS
+	help
+	  This enables build of the CMT system timer driver.
+
 config SH_TMU
 	def_bool y
 	prompt "TMU timer support"

drivers/clocksource/Makefile

@@ -2,3 +2,4 @@ obj-$(CONFIG_ATMEL_TCB_CLKSRC)	+= tcb_clksrc.o
 obj-$(CONFIG_X86_CYCLONE_TIMER)	+= cyclone.o
 obj-$(CONFIG_X86_PM_TIMER)	+= acpi_pm.o
 obj-$(CONFIG_SCx200HR_TIMER)	+= scx200_hrt.o
+obj-$(CONFIG_SH_TIMER_CMT)	+= sh_cmt.o

include/linux/sh_cmt.h

@@ -0,0 +1,13 @@
+#ifndef __SH_CMT_H__
+#define __SH_CMT_H__
+
+struct sh_cmt_config {
+	char *name;
+	unsigned long channel_offset;
+	int timer_bit;
+	char *clk;
+	unsigned long clockevent_rating;
+	unsigned long clocksource_rating;
+};
+
+#endif /* __SH_CMT_H__ */