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 39 /* 40 * timer_interrupt() needs to keep up the real-time clock, 41 * as well as call the "xtime_update()" routine every clocktick 42 */ 43 static irqreturn_t timer_interrupt(int irq, void *dummy) 44 { 45 xtime_update(1); 46 update_process_times(user_mode(get_irq_regs())); 47 profile_tick(CPU_PROFILING); 48 49 #ifdef CONFIG_HEARTBEAT 50 /* use power LED as a heartbeat instead -- much more useful 51 for debugging -- based on the version for PReP by Cort */ 52 /* acts like an actual heart beat -- ie thump-thump-pause... */ 53 if (mach_heartbeat) { 54 static unsigned cnt = 0, period = 0, dist = 0; 55 56 if (cnt == 0 || cnt == dist) 57 mach_heartbeat( 1 ); 58 else if (cnt == 7 || cnt == dist+7) 59 mach_heartbeat( 0 ); 60 61 if (++cnt > period) { 62 cnt = 0; 63 /* The hyperbolic function below modifies the heartbeat period 64 * length in dependency of the current (5min) load. It goes 65 * through the points f(0)=126, f(1)=86, f(5)=51, 66 * f(inf)->30. */ 67 period = ((672<<FSHIFT)/(5*avenrun[0]+(7<<FSHIFT))) + 30; 68 dist = period / 4; 69 } 70 } 71 #endif /* CONFIG_HEARTBEAT */ 72 return IRQ_HANDLED; 73 } 74 75 #ifdef CONFIG_M68KCLASSIC 76 #if !IS_BUILTIN(CONFIG_RTC_DRV_GENERIC) 77 void read_persistent_clock64(struct timespec64 *ts) 78 { 79 struct rtc_time time; 80 81 ts->tv_sec = 0; 82 ts->tv_nsec = 0; 83 84 if (!mach_hwclk) 85 return; 86 87 mach_hwclk(0, &time); 88 89 ts->tv_sec = mktime64(time.tm_year + 1900, time.tm_mon + 1, time.tm_mday, 90 time.tm_hour, time.tm_min, time.tm_sec); 91 } 92 #endif 93 94 #if IS_ENABLED(CONFIG_RTC_DRV_GENERIC) 95 static int rtc_generic_get_time(struct device *dev, struct rtc_time *tm) 96 { 97 mach_hwclk(0, tm); 98 return 0; 99 } 100 101 static int rtc_generic_set_time(struct device *dev, struct rtc_time *tm) 102 { 103 if (mach_hwclk(1, tm) < 0) 104 return -EOPNOTSUPP; 105 return 0; 106 } 107 108 static int rtc_ioctl(struct device *dev, unsigned int cmd, unsigned long arg) 109 { 110 struct rtc_pll_info pll; 111 struct rtc_pll_info __user *argp = (void __user *)arg; 112 113 switch (cmd) { 114 case RTC_PLL_GET: 115 if (!mach_get_rtc_pll || mach_get_rtc_pll(&pll)) 116 return -EINVAL; 117 return copy_to_user(argp, &pll, sizeof pll) ? -EFAULT : 0; 118 119 case RTC_PLL_SET: 120 if (!mach_set_rtc_pll) 121 return -EINVAL; 122 if (!capable(CAP_SYS_TIME)) 123 return -EACCES; 124 if (copy_from_user(&pll, argp, sizeof(pll))) 125 return -EFAULT; 126 return mach_set_rtc_pll(&pll); 127 } 128 129 return -ENOIOCTLCMD; 130 } 131 132 static const struct rtc_class_ops generic_rtc_ops = { 133 .ioctl = rtc_ioctl, 134 .read_time = rtc_generic_get_time, 135 .set_time = rtc_generic_set_time, 136 }; 137 138 static int __init rtc_init(void) 139 { 140 struct platform_device *pdev; 141 142 if (!mach_hwclk) 143 return -ENODEV; 144 145 pdev = platform_device_register_data(NULL, "rtc-generic", -1, 146 &generic_rtc_ops, 147 sizeof(generic_rtc_ops)); 148 return PTR_ERR_OR_ZERO(pdev); 149 } 150 151 module_init(rtc_init); 152 #endif /* CONFIG_RTC_DRV_GENERIC */ 153 #endif /* CONFIG M68KCLASSIC */ 154 155 void __init time_init(void) 156 { 157 mach_sched_init(timer_interrupt); 158 } 159