1 /* SPDX-License-Identifier: GPL-2.0 */
2 /*
3 * Copyright (C) 2020-2022 Loongson Technology Corporation Limited
4 */
5 #ifndef _ASM_TIME_H
6 #define _ASM_TIME_H
7
8 #include <linux/clockchips.h>
9 #include <linux/clocksource.h>
10 #include <asm/loongarch.h>
11
12 extern u64 cpu_clock_freq;
13 extern u64 const_clock_freq;
14
15 extern void save_counter(void);
16 extern void sync_counter(void);
17
18 static inline unsigned int calc_const_freq(void)
19 {
20 unsigned int res;
21 unsigned int base_freq;
22 unsigned int cfm, cfd;
23
24 res = read_cpucfg(LOONGARCH_CPUCFG2);
25 if (!(res & CPUCFG2_LLFTP))
26 return 0;
27
28 base_freq = read_cpucfg(LOONGARCH_CPUCFG4);
29 res = read_cpucfg(LOONGARCH_CPUCFG5);
30 cfm = res & 0xffff;
31 cfd = (res >> 16) & 0xffff;
32
33 if (!base_freq || !cfm || !cfd)
34 return 0;
35
36 return (base_freq * cfm / cfd);
37 }
38
39 /*
40 * Initialize the calling CPU's timer interrupt as clockevent device
41 */
42 extern int constant_clockevent_init(void);
43 extern int constant_clocksource_init(void);
44
45 static inline void clockevent_set_clock(struct clock_event_device *cd,
46 unsigned int clock)
47 {
48 clockevents_calc_mult_shift(cd, clock, 4);
49 }
50
51 #endif /* _ASM_TIME_H */
52
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.