blob: fc53492b6ad7fb67e904e88d2f02d184771a326e [file] [log] [blame]
/* 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!
#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 event notification values */
enum clock_event_nofitiers {
* 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
* @retries: number of forced programming retries
struct clock_event_device {
const char *name;
unsigned int features;
u64 max_delta_ns;
u64 min_delta_ns;
u32 mult;
u32 shift;
int rating;
int irq;
const struct cpumask *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)(const struct cpumask *mask);
struct list_head list;
enum clock_event_mode mode;
ktime_t next_event;
unsigned long retries;
* 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 u64 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_handle_noop(struct clock_event_device *dev);
static inline void
clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 minsec)
return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC,
freq, minsec);
extern void clockevents_notify(unsigned long reason, void *arg);
# define clockevents_notify(reason, arg) do { } while (0)
#define clockevents_notify(reason, arg) do { } while (0)