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/* linux/include/linux/clockchips.h
*
* This file contains the structure definitions for clockchips.
*
* If you are not a clockchip, or the time of day code, you should
* not be including this file!
*/
#ifndef _LINUX_CLOCKCHIPS_H
#define _LINUX_CLOCKCHIPS_H
#ifdef CONFIG_GENERIC_CLOCKEVENTS
#include <linux/clocksource.h>
#include <linux/cpumask.h>
#include <linux/ktime.h>
#include <linux/notifier.h>
struct clock_event_device;
/* Clock event mode commands */
enum clock_event_mode {
CLOCK_EVT_MODE_UNUSED = 0,
CLOCK_EVT_MODE_SHUTDOWN,
CLOCK_EVT_MODE_PERIODIC,
CLOCK_EVT_MODE_ONESHOT,
CLOCK_EVT_MODE_RESUME,
};
/* Clock event notification values */
enum clock_event_nofitiers {
CLOCK_EVT_NOTIFY_ADD,
CLOCK_EVT_NOTIFY_BROADCAST_ON,
CLOCK_EVT_NOTIFY_BROADCAST_OFF,
CLOCK_EVT_NOTIFY_BROADCAST_ENTER,
CLOCK_EVT_NOTIFY_BROADCAST_EXIT,
CLOCK_EVT_NOTIFY_SUSPEND,
CLOCK_EVT_NOTIFY_RESUME,
CLOCK_EVT_NOTIFY_CPU_DEAD,
};
/*
* Clock event features
*/
#define CLOCK_EVT_FEAT_PERIODIC 0x000001
#define CLOCK_EVT_FEAT_ONESHOT 0x000002
/*
* x86(64) specific misfeatures:
*
* - Clockevent source stops in C3 State and needs broadcast support.
* - Local APIC timer is used as a dummy device.
*/
#define CLOCK_EVT_FEAT_C3STOP 0x000004
#define CLOCK_EVT_FEAT_DUMMY 0x000008
/**
* struct clock_event_device - clock event device descriptor
* @name: ptr to clock event name
* @features: features
* @max_delta_ns: maximum delta value in ns
* @min_delta_ns: minimum delta value in ns
* @mult: nanosecond to cycles multiplier
* @shift: nanoseconds to cycles divisor (power of two)
* @rating: variable to rate clock event devices
* @irq: IRQ number (only for non CPU local devices)
* @cpumask: cpumask to indicate for which CPUs this device works
* @set_next_event: set next event function
* @set_mode: set mode function
* @event_handler: Assigned by the framework to be called by the low
* level handler of the event source
* @broadcast: function to broadcast events
* @list: list head for the management code
* @mode: operating mode assigned by the management code
* @next_event: local storage for the next event in oneshot mode
*/
struct clock_event_device {
const char *name;
unsigned int features;
unsigned long max_delta_ns;
unsigned long min_delta_ns;
unsigned long mult;
int shift;
int rating;
int irq;
cpumask_t cpumask;
int (*set_next_event)(unsigned long evt,
struct clock_event_device *);
void (*set_mode)(enum clock_event_mode mode,
struct clock_event_device *);
void (*event_handler)(struct clock_event_device *);
void (*broadcast)(cpumask_t mask);
struct list_head list;
enum clock_event_mode mode;
ktime_t next_event;
};
/*
* Calculate a multiplication factor for scaled math, which is used to convert
* nanoseconds based values to clock ticks:
*
* clock_ticks = (nanoseconds * factor) >> shift.
*
* div_sc is the rearranged equation to calculate a factor from a given clock
* ticks / nanoseconds ratio:
*
* factor = (clock_ticks << shift) / nanoseconds
*/
static inline unsigned long div_sc(unsigned long ticks, unsigned long nsec,
int shift)
{
uint64_t tmp = ((uint64_t)ticks) << shift;
do_div(tmp, nsec);
return (unsigned long) tmp;
}
/* Clock event layer functions */
extern unsigned long clockevent_delta2ns(unsigned long latch,
struct clock_event_device *evt);
extern void clockevents_register_device(struct clock_event_device *dev);
extern void clockevents_exchange_device(struct clock_event_device *old,
struct clock_event_device *new);
extern void clockevents_set_mode(struct clock_event_device *dev,
enum clock_event_mode mode);
extern int clockevents_register_notifier(struct notifier_block *nb);
extern int clockevents_program_event(struct clock_event_device *dev,
ktime_t expires, ktime_t now);
extern void clockevents_notify(unsigned long reason, void *arg);
#else
#define clockevents_notify(reason, arg) do { } while (0)
#endif
#endif
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