original_kernel/include/asm-sh/timer.h

#ifndef __ASM_SH_TIMER_H
#define __ASM_SH_TIMER_H

#include <linux/sysdev.h>
#include <asm/cpu/timer.h>

struct sys_timer_ops {
	int (*init)(void);
	int (*start)(void);
	int (*stop)(void);
#ifndef CONFIG_GENERIC_TIME
	unsigned long (*get_offset)(void);
#endif
};

struct sys_timer {
	const char		*name;

	struct sys_device	dev;
	struct sys_timer_ops	*ops;

#ifdef CONFIG_NO_IDLE_HZ
	struct dyn_tick_timer	*dyn_tick;
#endif
};

#ifdef CONFIG_NO_IDLE_HZ
#define DYN_TICK_ENABLED	(1 << 1)

struct dyn_tick_timer {
	spinlock_t	lock;
	unsigned int	state;			/* Current state */
	int		(*enable)(void);	/* Enables dynamic tick */
	int		(*disable)(void);	/* Disables dynamic tick */
	void		(*reprogram)(unsigned long); /* Reprograms the timer */
	int		(*handler)(int, void *);
};

void timer_dyn_reprogram(void);
#else
#define timer_dyn_reprogram()	do { } while (0)
#endif

#define TICK_SIZE (tick_nsec / 1000)

extern struct sys_timer tmu_timer, cmt_timer, mtu2_timer;
extern struct sys_timer *sys_timer;

#ifndef CONFIG_GENERIC_TIME
static inline unsigned long get_timer_offset(void)
{
	return sys_timer->ops->get_offset();
}
#endif

/* arch/sh/kernel/timers/timer.c */
struct sys_timer *get_sys_timer(void);

/* arch/sh/kernel/time.c */
void handle_timer_tick(void);

#endif /* __ASM_SH_TIMER_H */