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 35 unsigned long (*mach_random_get_entropy)(void); 36 EXPORT_SYMBOL_GPL(mach_random_get_entropy); 37 38 #ifdef CONFIG_HEARTBEAT 39 void 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 #ifdef CONFIG_M68KCLASSIC 66 #if !IS_BUILTIN(CONFIG_RTC_DRV_GENERIC) 67 void read_persistent_clock64(struct timespec64 *ts) 68 { 69 struct rtc_time time; 70 71 ts->tv_sec = 0; 72 ts->tv_nsec = 0; 73 74 if (!mach_hwclk) 75 return; 76 77 mach_hwclk(0, &time); 78 79 ts->tv_sec = mktime64(time.tm_year + 1900, time.tm_mon + 1, time.tm_mday, 80 time.tm_hour, time.tm_min, time.tm_sec); 81 } 82 #endif 83 84 #if IS_ENABLED(CONFIG_RTC_DRV_GENERIC) 85 static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm) 86 { 87 mach_hwclk(0, tm); 88 return 0; 89 } 90 91 static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm) 92 { 93 if (mach_hwclk(1, tm) < 0) 94 return -EOPNOTSUPP; 95 return 0; 96 } 97 98 static int rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 99 { 100 struct rtc_pll_info pll; 101 struct rtc_pll_info __user *argp = (void __user *)arg; 102 103 switch (cmd) { 104 case RTC_PLL_GET: 105 if (!mach_get_rtc_pll || mach_get_rtc_pll(&pll)) 106 return -EINVAL; 107 return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0; 108 109 case RTC_PLL_SET: 110 if (!mach_set_rtc_pll) 111 return -EINVAL; 112 if (!capable(CAP_SYS_TIME)) 113 return -EACCES; 114 if (copy_from_user(&pll, argp, sizeof(pll))) 115 return -EFAULT; 116 return mach_set_rtc_pll(&pll); 117 } 118 119 return -ENOIOCTLCMD; 120 } 121 122 static const struct rtc_class_ops generic_rtc_ops = { 123 .ioctl = rtc_ioctl, 124 .read_time = rtc_generic_get_time, 125 .set_time = rtc_generic_set_time, 126 }; 127 128 static int __init rtc_init(void) 129 { 130 struct platform_device *pdev; 131 132 if (!mach_hwclk) 133 return -ENODEV; 134 135 pdev = platform_device_register_data(NULL, "rtc-generic", -1, 136 &generic_rtc_ops, 137 sizeof(generic_rtc_ops)); 138 return PTR_ERR_OR_ZERO(pdev); 139 } 140 141 module_init(rtc_init); 142 #endif /* CONFIG_RTC_DRV_GENERIC */ 143 #endif /* CONFIG M68KCLASSIC */ 144 145 void __init time_init(void) 146 { 147 mach_sched_init(); 148 } 149