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Diffstat (limited to '')
| -rw-r--r-- | include/linux/clockchips.h | 227 |
1 files changed, 227 insertions, 0 deletions
diff --git a/include/linux/clockchips.h b/include/linux/clockchips.h new file mode 100644 index 000000000..8ae9a95eb --- /dev/null +++ b/include/linux/clockchips.h @@ -0,0 +1,227 @@ +/* SPDX-License-Identifier: GPL-2.0 */ +/* 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; +struct module; + +/* + * Possible states of a clock event device. + * + * DETACHED: Device is not used by clockevents core. Initial state or can be + * reached from SHUTDOWN. + * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT. + * PERIODIC: Device is programmed to generate events periodically. Can be + * reached from DETACHED or SHUTDOWN. + * ONESHOT: Device is programmed to generate event only once. Can be reached + * from DETACHED or SHUTDOWN. + * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily + * stopped. + */ +enum clock_event_state { + CLOCK_EVT_STATE_DETACHED, + CLOCK_EVT_STATE_SHUTDOWN, + CLOCK_EVT_STATE_PERIODIC, + CLOCK_EVT_STATE_ONESHOT, + CLOCK_EVT_STATE_ONESHOT_STOPPED, +}; + +/* + * Clock event features + */ +# define CLOCK_EVT_FEAT_PERIODIC 0x000001 +# define CLOCK_EVT_FEAT_ONESHOT 0x000002 +# define CLOCK_EVT_FEAT_KTIME 0x000004 + +/* + * x86(64) specific (mis)features: + * + * - Clockevent source stops in C3 State and needs broadcast support. + * - Local APIC timer is used as a dummy device. + */ +# define CLOCK_EVT_FEAT_C3STOP 0x000008 +# define CLOCK_EVT_FEAT_DUMMY 0x000010 + +/* + * Core shall set the interrupt affinity dynamically in broadcast mode + */ +# define CLOCK_EVT_FEAT_DYNIRQ 0x000020 +# define CLOCK_EVT_FEAT_PERCPU 0x000040 + +/* + * Clockevent device is based on a hrtimer for broadcast + */ +# define CLOCK_EVT_FEAT_HRTIMER 0x000080 + +/** + * 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 using a clocksource delta + * @set_next_ktime: set next event function using a direct ktime value + * @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) + * @state_use_accessors:current state of the device, assigned by the core code + * @features: features + * @retries: number of forced programming retries + * @set_state_periodic: switch state to periodic + * @set_state_oneshot: switch state to oneshot + * @set_state_oneshot_stopped: switch state to oneshot_stopped + * @set_state_shutdown: switch state to shutdown + * @tick_resume: resume clkevt device + * @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) + * @bound_on: Bound on CPU + * @cpumask: cpumask to indicate for which CPUs this device works + * @list: list head for the management code + * @owner: module reference + */ +struct clock_event_device { + void (*event_handler)(struct clock_event_device *); + int (*set_next_event)(unsigned long evt, struct clock_event_device *); + int (*set_next_ktime)(ktime_t expires, struct clock_event_device *); + ktime_t next_event; + u64 max_delta_ns; + u64 min_delta_ns; + u32 mult; + u32 shift; + enum clock_event_state state_use_accessors; + unsigned int features; + unsigned long retries; + + int (*set_state_periodic)(struct clock_event_device *); + int (*set_state_oneshot)(struct clock_event_device *); + int (*set_state_oneshot_stopped)(struct clock_event_device *); + int (*set_state_shutdown)(struct clock_event_device *); + int (*tick_resume)(struct clock_event_device *); + + void (*broadcast)(const struct cpumask *mask); + void (*suspend)(struct clock_event_device *); + void (*resume)(struct clock_event_device *); + unsigned long min_delta_ticks; + unsigned long max_delta_ticks; + + const char *name; + int rating; + int irq; + int bound_on; + const struct cpumask *cpumask; + struct list_head list; + struct module *owner; +} ____cacheline_aligned; + +/* Helpers to verify state of a clockevent device */ +static inline bool clockevent_state_detached(struct clock_event_device *dev) +{ + return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED; +} + +static inline bool clockevent_state_shutdown(struct clock_event_device *dev) +{ + return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN; +} + +static inline bool clockevent_state_periodic(struct clock_event_device *dev) +{ + return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC; +} + +static inline bool clockevent_state_oneshot(struct clock_event_device *dev) +{ + return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT; +} + +static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev) +{ + return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED; +} + +/* + * 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) +{ + u64 tmp = ((u64)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 int clockevents_unbind_device(struct clock_event_device *ced, int cpu); + +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); + +static inline void +clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 maxsec) +{ + return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, maxsec); +} + +extern void clockevents_suspend(void); +extern void clockevents_resume(void); + +# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST +# ifdef CONFIG_ARCH_HAS_TICK_BROADCAST +extern void tick_broadcast(const struct cpumask *mask); +# else +# define tick_broadcast NULL +# endif +extern int tick_receive_broadcast(void); +# endif + +# if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) +extern void tick_setup_hrtimer_broadcast(void); +extern int tick_check_broadcast_expired(void); +# else +static inline int tick_check_broadcast_expired(void) { return 0; } +static inline void tick_setup_hrtimer_broadcast(void) { } +# endif + +#else /* !CONFIG_GENERIC_CLOCKEVENTS: */ + +static inline void clockevents_suspend(void) { } +static inline void clockevents_resume(void) { } +static inline int tick_check_broadcast_expired(void) { return 0; } +static inline void tick_setup_hrtimer_broadcast(void) { } + +#endif /* !CONFIG_GENERIC_CLOCKEVENTS */ + +#endif /* _LINUX_CLOCKCHIPS_H */ |