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1/* SPDX-License-Identifier: GPL-2.0 */2/* linux/include/linux/clockchips.h3 *4 * This file contains the structure definitions for clockchips.5 *6 * If you are not a clockchip, or the time of day code, you should7 * not be including this file!8 */9#ifndef _LINUX_CLOCKCHIPS_H10#define _LINUX_CLOCKCHIPS_H11 12#ifdef CONFIG_GENERIC_CLOCKEVENTS13 14# include <linux/clocksource.h>15# include <linux/cpumask_types.h>16# include <linux/ktime.h>17# include <linux/notifier.h>18 19struct clock_event_device;20struct module;21 22/*23 * Possible states of a clock event device.24 *25 * DETACHED: Device is not used by clockevents core. Initial state or can be26 * reached from SHUTDOWN.27 * SHUTDOWN: Device is powered-off. Can be reached from PERIODIC or ONESHOT.28 * PERIODIC: Device is programmed to generate events periodically. Can be29 * reached from DETACHED or SHUTDOWN.30 * ONESHOT: Device is programmed to generate event only once. Can be reached31 * from DETACHED or SHUTDOWN.32 * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily33 * stopped.34 */35enum clock_event_state {36 CLOCK_EVT_STATE_DETACHED,37 CLOCK_EVT_STATE_SHUTDOWN,38 CLOCK_EVT_STATE_PERIODIC,39 CLOCK_EVT_STATE_ONESHOT,40 CLOCK_EVT_STATE_ONESHOT_STOPPED,41};42 43/*44 * Clock event features45 */46# define CLOCK_EVT_FEAT_PERIODIC 0x00000147# define CLOCK_EVT_FEAT_ONESHOT 0x00000248# define CLOCK_EVT_FEAT_KTIME 0x00000449 50/*51 * x86(64) specific (mis)features:52 *53 * - Clockevent source stops in C3 State and needs broadcast support.54 * - Local APIC timer is used as a dummy device.55 */56# define CLOCK_EVT_FEAT_C3STOP 0x00000857# define CLOCK_EVT_FEAT_DUMMY 0x00001058 59/*60 * Core shall set the interrupt affinity dynamically in broadcast mode61 */62# define CLOCK_EVT_FEAT_DYNIRQ 0x00002063# define CLOCK_EVT_FEAT_PERCPU 0x00004064 65/*66 * Clockevent device is based on a hrtimer for broadcast67 */68# define CLOCK_EVT_FEAT_HRTIMER 0x00008069 70/**71 * struct clock_event_device - clock event device descriptor72 * @event_handler: Assigned by the framework to be called by the low73 * level handler of the event source74 * @set_next_event: set next event function using a clocksource delta75 * @set_next_ktime: set next event function using a direct ktime value76 * @next_event: local storage for the next event in oneshot mode77 * @max_delta_ns: maximum delta value in ns78 * @min_delta_ns: minimum delta value in ns79 * @mult: nanosecond to cycles multiplier80 * @shift: nanoseconds to cycles divisor (power of two)81 * @state_use_accessors:current state of the device, assigned by the core code82 * @features: features83 * @retries: number of forced programming retries84 * @set_state_periodic: switch state to periodic85 * @set_state_oneshot: switch state to oneshot86 * @set_state_oneshot_stopped: switch state to oneshot_stopped87 * @set_state_shutdown: switch state to shutdown88 * @tick_resume: resume clkevt device89 * @broadcast: function to broadcast events90 * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration91 * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration92 * @name: ptr to clock event name93 * @rating: variable to rate clock event devices94 * @irq: IRQ number (only for non CPU local devices)95 * @bound_on: Bound on CPU96 * @cpumask: cpumask to indicate for which CPUs this device works97 * @list: list head for the management code98 * @owner: module reference99 */100struct clock_event_device {101 void (*event_handler)(struct clock_event_device *);102 int (*set_next_event)(unsigned long evt, struct clock_event_device *);103 int (*set_next_ktime)(ktime_t expires, struct clock_event_device *);104 ktime_t next_event;105 u64 max_delta_ns;106 u64 min_delta_ns;107 u32 mult;108 u32 shift;109 enum clock_event_state state_use_accessors;110 unsigned int features;111 unsigned long retries;112 113 int (*set_state_periodic)(struct clock_event_device *);114 int (*set_state_oneshot)(struct clock_event_device *);115 int (*set_state_oneshot_stopped)(struct clock_event_device *);116 int (*set_state_shutdown)(struct clock_event_device *);117 int (*tick_resume)(struct clock_event_device *);118 119 void (*broadcast)(const struct cpumask *mask);120 void (*suspend)(struct clock_event_device *);121 void (*resume)(struct clock_event_device *);122 unsigned long min_delta_ticks;123 unsigned long max_delta_ticks;124 125 const char *name;126 int rating;127 int irq;128 int bound_on;129 const struct cpumask *cpumask;130 struct list_head list;131 struct module *owner;132} ____cacheline_aligned;133 134/* Helpers to verify state of a clockevent device */135static inline bool clockevent_state_detached(struct clock_event_device *dev)136{137 return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED;138}139 140static inline bool clockevent_state_shutdown(struct clock_event_device *dev)141{142 return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN;143}144 145static inline bool clockevent_state_periodic(struct clock_event_device *dev)146{147 return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC;148}149 150static inline bool clockevent_state_oneshot(struct clock_event_device *dev)151{152 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT;153}154 155static inline bool clockevent_state_oneshot_stopped(struct clock_event_device *dev)156{157 return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT_STOPPED;158}159 160/*161 * Calculate a multiplication factor for scaled math, which is used to convert162 * nanoseconds based values to clock ticks:163 *164 * clock_ticks = (nanoseconds * factor) >> shift.165 *166 * div_sc is the rearranged equation to calculate a factor from a given clock167 * ticks / nanoseconds ratio:168 *169 * factor = (clock_ticks << shift) / nanoseconds170 */171static inline unsigned long172div_sc(unsigned long ticks, unsigned long nsec, int shift)173{174 u64 tmp = ((u64)ticks) << shift;175 176 do_div(tmp, nsec);177 178 return (unsigned long) tmp;179}180 181/* Clock event layer functions */182extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt);183extern void clockevents_register_device(struct clock_event_device *dev);184extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu) HWJS_SUSPENDS;185 186extern void clockevents_config_and_register(struct clock_event_device *dev,187 u32 freq, unsigned long min_delta,188 unsigned long max_delta);189 190extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq);191 192static inline void193clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 maxsec)194{195 return clocks_calc_mult_shift(&ce->mult, &ce->shift, NSEC_PER_SEC, freq, maxsec);196}197 198extern void clockevents_suspend(void);199extern void clockevents_resume(void);200 201# ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST202# ifdef CONFIG_ARCH_HAS_TICK_BROADCAST203extern void tick_broadcast(const struct cpumask *mask);204# else205# define tick_broadcast NULL206# endif207extern int tick_receive_broadcast(void);208# endif209 210# if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT)211extern void tick_setup_hrtimer_broadcast(void);212extern int tick_check_broadcast_expired(void);213# else214static __always_inline int tick_check_broadcast_expired(void) { return 0; }215static inline void tick_setup_hrtimer_broadcast(void) { }216# endif217 218#else /* !CONFIG_GENERIC_CLOCKEVENTS: */219 220static inline void clockevents_suspend(void) { }221static inline void clockevents_resume(void) { }222static __always_inline int tick_check_broadcast_expired(void) { return 0; }223static inline void tick_setup_hrtimer_broadcast(void) { }224 225#endif /* !CONFIG_GENERIC_CLOCKEVENTS */226 227#endif /* _LINUX_CLOCKCHIPS_H */228