diff options
Diffstat (limited to 'include/linux/clockchips.h')
| -rw-r--r-- | include/linux/clockchips.h | 172 |
1 files changed, 172 insertions, 0 deletions
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h new file mode 100644 index 00000000..acc14353 --- /dev/null +++ b/include/linux/clockchips.h @@ -0,0 +1,172 @@ +/* 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_BUILD + +#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_FORCE, + CLOCK_EVT_NOTIFY_BROADCAST_ENTER, + CLOCK_EVT_NOTIFY_BROADCAST_EXIT, + CLOCK_EVT_NOTIFY_SUSPEND, + CLOCK_EVT_NOTIFY_RESUME, + CLOCK_EVT_NOTIFY_CPU_DYING, + 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 + * @event_handler: Assigned by the framework to be called by the low + * level handler of the event source + * @set_next_event: set next event function + * @next_event: local storage for the next event in oneshot mode + * @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) + * @mode: operating mode assigned by the management code + * @features: features + * @retries: number of forced programming retries + * @set_mode: set mode function + * @broadcast: function to broadcast events + * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration + * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration + * @name: ptr to clock event name + * @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 + * @list: list head for the management code + */ +struct clock_event_device { + void (*event_handler)(struct clock_event_device *); + int (*set_next_event)(unsigned long evt, + struct clock_event_device *); + ktime_t next_event; + u64 max_delta_ns; + u64 min_delta_ns; + u32 mult; + u32 shift; + enum clock_event_mode mode; + unsigned int features; + unsigned long retries; + + void (*broadcast)(const struct cpumask *mask); + void (*set_mode)(enum clock_event_mode mode, + struct clock_event_device *); + unsigned long min_delta_ticks; + unsigned long max_delta_ticks; + + const char *name; + int rating; + int irq; + const struct cpumask *cpumask; + struct list_head list; +} ____cacheline_aligned; + +/* + * 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_config_and_register(struct clock_event_device *dev, + u32 freq, unsigned long min_delta, + unsigned long max_delta); + +extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); + +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); +} + +#if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) +extern int tick_check_broadcast_pending(void); +#else +static inline int tick_check_broadcast_pending(void) { return 0; } +#endif + +#ifdef CONFIG_GENERIC_CLOCKEVENTS +extern void clockevents_notify(unsigned long reason, void *arg); +#else +# define clockevents_notify(reason, arg) do { } while (0) +#endif + +#else /* CONFIG_GENERIC_CLOCKEVENTS_BUILD */ + +#define clockevents_notify(reason, arg) do { } while (0) + +#endif + +#endif |