1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | /* linux/include/linux/clockchips.h |
3 | * |
4 | * This file contains the structure definitions for clockchips. |
5 | * |
6 | * If you are not a clockchip, or the time of day code, you should |
7 | * not be including this file! |
8 | */ |
9 | #ifndef _LINUX_CLOCKCHIPS_H |
10 | #define _LINUX_CLOCKCHIPS_H |
11 | |
12 | #ifdef CONFIG_GENERIC_CLOCKEVENTS |
13 | |
14 | # include <linux/clocksource.h> |
15 | # include <linux/cpumask.h> |
16 | # include <linux/ktime.h> |
17 | # include <linux/notifier.h> |
18 | |
19 | struct clock_event_device; |
20 | struct 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 be |
26 | * 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 be |
29 | * reached from DETACHED or SHUTDOWN. |
30 | * ONESHOT: Device is programmed to generate event only once. Can be reached |
31 | * from DETACHED or SHUTDOWN. |
32 | * ONESHOT_STOPPED: Device was programmed in ONESHOT mode and is temporarily |
33 | * stopped. |
34 | */ |
35 | enum 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 features |
45 | */ |
46 | # define CLOCK_EVT_FEAT_PERIODIC 0x000001 |
47 | # define CLOCK_EVT_FEAT_ONESHOT 0x000002 |
48 | # define CLOCK_EVT_FEAT_KTIME 0x000004 |
49 | |
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 0x000008 |
57 | # define CLOCK_EVT_FEAT_DUMMY 0x000010 |
58 | |
59 | /* |
60 | * Core shall set the interrupt affinity dynamically in broadcast mode |
61 | */ |
62 | # define CLOCK_EVT_FEAT_DYNIRQ 0x000020 |
63 | # define CLOCK_EVT_FEAT_PERCPU 0x000040 |
64 | |
65 | /* |
66 | * Clockevent device is based on a hrtimer for broadcast |
67 | */ |
68 | # define CLOCK_EVT_FEAT_HRTIMER 0x000080 |
69 | |
70 | /** |
71 | * struct clock_event_device - clock event device descriptor |
72 | * @event_handler: Assigned by the framework to be called by the low |
73 | * level handler of the event source |
74 | * @set_next_event: set next event function using a clocksource delta |
75 | * @set_next_ktime: set next event function using a direct ktime value |
76 | * @next_event: local storage for the next event in oneshot mode |
77 | * @max_delta_ns: maximum delta value in ns |
78 | * @min_delta_ns: minimum delta value in ns |
79 | * @mult: nanosecond to cycles multiplier |
80 | * @shift: nanoseconds to cycles divisor (power of two) |
81 | * @state_use_accessors:current state of the device, assigned by the core code |
82 | * @features: features |
83 | * @retries: number of forced programming retries |
84 | * @set_state_periodic: switch state to periodic |
85 | * @set_state_oneshot: switch state to oneshot |
86 | * @set_state_oneshot_stopped: switch state to oneshot_stopped |
87 | * @set_state_shutdown: switch state to shutdown |
88 | * @tick_resume: resume clkevt device |
89 | * @broadcast: function to broadcast events |
90 | * @min_delta_ticks: minimum delta value in ticks stored for reconfiguration |
91 | * @max_delta_ticks: maximum delta value in ticks stored for reconfiguration |
92 | * @name: ptr to clock event name |
93 | * @rating: variable to rate clock event devices |
94 | * @irq: IRQ number (only for non CPU local devices) |
95 | * @bound_on: Bound on CPU |
96 | * @cpumask: cpumask to indicate for which CPUs this device works |
97 | * @list: list head for the management code |
98 | * @owner: module reference |
99 | */ |
100 | struct 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 */ |
135 | static inline bool clockevent_state_detached(struct clock_event_device *dev) |
136 | { |
137 | return dev->state_use_accessors == CLOCK_EVT_STATE_DETACHED; |
138 | } |
139 | |
140 | static inline bool clockevent_state_shutdown(struct clock_event_device *dev) |
141 | { |
142 | return dev->state_use_accessors == CLOCK_EVT_STATE_SHUTDOWN; |
143 | } |
144 | |
145 | static inline bool clockevent_state_periodic(struct clock_event_device *dev) |
146 | { |
147 | return dev->state_use_accessors == CLOCK_EVT_STATE_PERIODIC; |
148 | } |
149 | |
150 | static inline bool clockevent_state_oneshot(struct clock_event_device *dev) |
151 | { |
152 | return dev->state_use_accessors == CLOCK_EVT_STATE_ONESHOT; |
153 | } |
154 | |
155 | static 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 convert |
162 | * 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 clock |
167 | * ticks / nanoseconds ratio: |
168 | * |
169 | * factor = (clock_ticks << shift) / nanoseconds |
170 | */ |
171 | static inline unsigned long |
172 | div_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 */ |
182 | extern u64 clockevent_delta2ns(unsigned long latch, struct clock_event_device *evt); |
183 | extern void clockevents_register_device(struct clock_event_device *dev); |
184 | extern int clockevents_unbind_device(struct clock_event_device *ced, int cpu); |
185 | |
186 | extern void clockevents_config_and_register(struct clock_event_device *dev, |
187 | u32 freq, unsigned long min_delta, |
188 | unsigned long max_delta); |
189 | |
190 | extern int clockevents_update_freq(struct clock_event_device *ce, u32 freq); |
191 | |
192 | static inline void |
193 | clockevents_calc_mult_shift(struct clock_event_device *ce, u32 freq, u32 maxsec) |
194 | { |
195 | return clocks_calc_mult_shift(mult: &ce->mult, shift: &ce->shift, NSEC_PER_SEC, to: freq, minsec: maxsec); |
196 | } |
197 | |
198 | extern void clockevents_suspend(void); |
199 | extern void clockevents_resume(void); |
200 | |
201 | # ifdef CONFIG_GENERIC_CLOCKEVENTS_BROADCAST |
202 | # ifdef CONFIG_ARCH_HAS_TICK_BROADCAST |
203 | extern void tick_broadcast(const struct cpumask *mask); |
204 | # else |
205 | # define tick_broadcast NULL |
206 | # endif |
207 | extern int tick_receive_broadcast(void); |
208 | # endif |
209 | |
210 | # if defined(CONFIG_GENERIC_CLOCKEVENTS_BROADCAST) && defined(CONFIG_TICK_ONESHOT) |
211 | extern void tick_setup_hrtimer_broadcast(void); |
212 | extern int tick_check_broadcast_expired(void); |
213 | # else |
214 | static __always_inline int tick_check_broadcast_expired(void) { return 0; } |
215 | static inline void tick_setup_hrtimer_broadcast(void) { } |
216 | # endif |
217 | |
218 | #else /* !CONFIG_GENERIC_CLOCKEVENTS: */ |
219 | |
220 | static inline void clockevents_suspend(void) { } |
221 | static inline void clockevents_resume(void) { } |
222 | static __always_inline int tick_check_broadcast_expired(void) { return 0; } |
223 | static inline void tick_setup_hrtimer_broadcast(void) { } |
224 | |
225 | #endif /* !CONFIG_GENERIC_CLOCKEVENTS */ |
226 | |
227 | #endif /* _LINUX_CLOCKCHIPS_H */ |
228 | |