projects/linux·blob master · refs

157 lines · 3.7 KiB

1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/arch/m68k/kernel/time.c
4 *
5 * Copyright (C) 1991, 1992, 1995 Linus Torvalds
6 *
7 * This file contains the m68k-specific time handling details.
8 * Most of the stuff is located in the machine specific files.
9 *
10 * 1997-09-10 Updated NTP code according to technical memorandum Jan '96
11 * "A Kernel Model for Precision Timekeeping" by Dave Mills
12 */
13
14#include <linux/errno.h>
15#include <linux/export.h>
16#include <linux/module.h>
17#include <linux/sched.h>
18#include <linux/sched/loadavg.h>
19#include <linux/kernel.h>
20#include <linux/param.h>
21#include <linux/string.h>
22#include <linux/mm.h>
23#include <linux/rtc.h>
24#include <linux/platform_device.h>
25
26#include <asm/machdep.h>
27#include <asm/io.h>
28#include <asm/irq_regs.h>
29
30#include <linux/time.h>
31#include <linux/timex.h>
32#include <linux/profile.h>
33
34
35unsigned long (*mach_random_get_entropy)(void);
36EXPORT_SYMBOL_GPL(mach_random_get_entropy);
37
38#ifdef CONFIG_HEARTBEAT
39void timer_heartbeat(void)
40{
41 /* use power LED as a heartbeat instead -- much more useful
42 for debugging -- based on the version for PReP by Cort */
43 /* acts like an actual heart beat -- ie thump-thump-pause... */
44 if (mach_heartbeat) {
45 static unsigned cnt = 0, period = 0, dist = 0;
46
47 if (cnt == 0 || cnt == dist)
48 mach_heartbeat( 1 );
49 else if (cnt == 7 || cnt == dist+7)
50 mach_heartbeat( 0 );
51
52 if (++cnt > period) {
53 cnt = 0;
54 /* The hyperbolic function below modifies the heartbeat period
55 * length in dependency of the current (5min) load. It goes
56 * through the points f(0)=126, f(1)=86, f(5)=51,
57 * f(inf)->30. */
58 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30;
59 dist = period / 4;
60 }
61 }
62}
63#endif /* CONFIG_HEARTBEAT */
64
65#if defined(CONFIG_M68KCLASSIC) || defined(CONFIG_SUN3)
66/* machine dependent timer functions */
67int (*mach_hwclk) (int, struct rtc_time*);
68EXPORT_SYMBOL(mach_hwclk);
69
70int (*mach_get_rtc_pll)(struct rtc_pll_info *);
71int (*mach_set_rtc_pll)(struct rtc_pll_info *);
72EXPORT_SYMBOL(mach_get_rtc_pll);
73EXPORT_SYMBOL(mach_set_rtc_pll);
74
75#if !IS_BUILTIN(CONFIG_RTC_DRV_GENERIC)
76void read_persistent_clock64(struct timespec64 *ts)
77{
78 struct rtc_time time;
79
80 ts->tv_sec = 0;
81 ts->tv_nsec = 0;
82
83 if (!mach_hwclk)
84 return;
85
86 mach_hwclk(0, &time);
87
88 ts->tv_sec = mktime64(time.tm_year + 1900, time.tm_mon + 1, time.tm_mday,
89 time.tm_hour, time.tm_min, time.tm_sec);
90}
91#endif
92
93#if IS_ENABLED(CONFIG_RTC_DRV_GENERIC)
94static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm)
95{
96 mach_hwclk(0, tm);
97 return 0;
98}
99
100static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm)
101{
102 if (mach_hwclk(1, tm) < 0)
103 return -EOPNOTSUPP;
104 return 0;
105}
106
107static int rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg)
108{
109 struct rtc_pll_info pll;
110 struct rtc_pll_info __user *argp = (void __user *)arg;
111
112 switch (cmd) {
113 case RTC_PLL_GET:
114 if (!mach_get_rtc_pll || mach_get_rtc_pll(&pll))
115 return -EINVAL;
116 return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0;
117
118 case RTC_PLL_SET:
119 if (!mach_set_rtc_pll)
120 return -EINVAL;
121 if (!capable(CAP_SYS_TIME))
122 return -EACCES;
123 if (copy_from_user(&pll, argp, sizeof(pll)))
124 return -EFAULT;
125 return mach_set_rtc_pll(&pll);
126 }
127
128 return -ENOIOCTLCMD;
129}
130
131static const struct rtc_class_ops generic_rtc_ops = {
132 .ioctl = rtc_ioctl,
133 .read_time = rtc_generic_get_time,
134 .set_time = rtc_generic_set_time,
135};
136
137static int __init rtc_init(void)
138{
139 struct platform_device *pdev;
140
141 if (!mach_hwclk)
142 return -ENODEV;
143
144 pdev = platform_device_register_data(NULL, "rtc-generic", -1,
145 &generic_rtc_ops,
146 sizeof(generic_rtc_ops));
147 return PTR_ERR_OR_ZERO(pdev);
148}
149
150module_init(rtc_init);
151#endif /* CONFIG_RTC_DRV_GENERIC */
152#endif /* CONFIG_M68KCLASSIC || SUN3 */
153
154void __init time_init(void)
155{
156 mach_sched_init();
157}