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 /* machine dependent timer functions */ 67 int (*mach_hwclk) (int, struct rtc_time*); 68 EXPORT_SYMBOL(mach_hwclk); 69 70 int (*mach_get_rtc_pll)(struct rtc_pll_info *); 71 int (*mach_set_rtc_pll)(struct rtc_pll_info *); 72 EXPORT_SYMBOL(mach_get_rtc_pll); 73 EXPORT_SYMBOL(mach_set_rtc_pll); 74 75 #if !IS_BUILTIN(CONFIG_RTC_DRV_GENERIC) 76 void 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) 94 static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm) 95 { 96 mach_hwclk(0, tm); 97 return 0; 98 } 99 100 static 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 } 106 107 static 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 } 130 131 static 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 }; 136 137 static 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 } 149 150 module_init(rtc_init); 151 #endif /* CONFIG_RTC_DRV_GENERIC */ 152 #endif /* CONFIG M68KCLASSIC */ 153 154 void __init time_init(void) 155 { 156 mach_sched_init(); 157 } 158