1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support 4 * 5 * Copyright (C) 2004 Saito.K & Jeanne(ksaito@interface.co.jp) 6 * 7 */ 8 9 #include <linux/init.h> 10 #include <linux/kernel.h> 11 #include <linux/sched.h> 12 #include <linux/time.h> 13 #include <linux/bcd.h> 14 #include <linux/rtc.h> 15 #include <linux/spinlock.h> 16 #include <linux/io.h> 17 #include <linux/rtc.h> 18 #include <linux/platform_device.h> 19 20 #define RTC_BASE 0xb0000000 21 #define RTC_SEC1 (RTC_BASE + 0) 22 #define RTC_SEC10 (RTC_BASE + 1) 23 #define RTC_MIN1 (RTC_BASE + 2) 24 #define RTC_MIN10 (RTC_BASE + 3) 25 #define RTC_HOU1 (RTC_BASE + 4) 26 #define RTC_HOU10 (RTC_BASE + 5) 27 #define RTC_WEE1 (RTC_BASE + 6) 28 #define RTC_DAY1 (RTC_BASE + 7) 29 #define RTC_DAY10 (RTC_BASE + 8) 30 #define RTC_MON1 (RTC_BASE + 9) 31 #define RTC_MON10 (RTC_BASE + 10) 32 #define RTC_YEA1 (RTC_BASE + 11) 33 #define RTC_YEA10 (RTC_BASE + 12) 34 #define RTC_YEA100 (RTC_BASE + 13) 35 #define RTC_YEA1000 (RTC_BASE + 14) 36 #define RTC_CTL (RTC_BASE + 15) 37 #define RTC_BUSY 1 38 #define RTC_STOP 2 39 40 static DEFINE_SPINLOCK(sh03_rtc_lock); 41 42 static int sh03_rtc_gettimeofday(struct device *dev, struct rtc_time *tm) 43 { 44 unsigned int year, mon, day, hour, min, sec; 45 46 spin_lock(&sh03_rtc_lock); 47 again: 48 do { 49 sec = (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10; 50 min = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10; 51 hour = (__raw_readb(RTC_HOU1) & 0xf) + (__raw_readb(RTC_HOU10) & 0xf) * 10; 52 day = (__raw_readb(RTC_DAY1) & 0xf) + (__raw_readb(RTC_DAY10) & 0xf) * 10; 53 mon = (__raw_readb(RTC_MON1) & 0xf) + (__raw_readb(RTC_MON10) & 0xf) * 10; 54 year = (__raw_readb(RTC_YEA1) & 0xf) + (__raw_readb(RTC_YEA10) & 0xf) * 10 55 + (__raw_readb(RTC_YEA100 ) & 0xf) * 100 56 + (__raw_readb(RTC_YEA1000) & 0xf) * 1000; 57 } while (sec != (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10); 58 if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 || 59 hour > 23 || min > 59 || sec > 59) { 60 printk(KERN_ERR 61 "SH-03 RTC: invalid value, resetting to 1 Jan 2000\n"); 62 printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n", 63 year, mon, day, hour, min, sec); 64 65 __raw_writeb(0, RTC_SEC1); __raw_writeb(0, RTC_SEC10); 66 __raw_writeb(0, RTC_MIN1); __raw_writeb(0, RTC_MIN10); 67 __raw_writeb(0, RTC_HOU1); __raw_writeb(0, RTC_HOU10); 68 __raw_writeb(6, RTC_WEE1); 69 __raw_writeb(1, RTC_DAY1); __raw_writeb(0, RTC_DAY10); 70 __raw_writeb(1, RTC_MON1); __raw_writeb(0, RTC_MON10); 71 __raw_writeb(0, RTC_YEA1); __raw_writeb(0, RTC_YEA10); 72 __raw_writeb(0, RTC_YEA100); 73 __raw_writeb(2, RTC_YEA1000); 74 __raw_writeb(0, RTC_CTL); 75 goto again; 76 } 77 78 spin_unlock(&sh03_rtc_lock); 79 80 tm->tm_sec = sec; 81 tm->tm_min = min; 82 tm->tm_hour = hour; 83 tm->tm_mday = day; 84 tm->tm_mon = mon; 85 tm->tm_year = year - 1900; 86 87 return 0; 88 } 89 90 static int set_rtc_mmss(struct rtc_time *tm) 91 { 92 int retval = 0; 93 int real_seconds, real_minutes, cmos_minutes; 94 int i; 95 96 /* gets recalled with irq locally disabled */ 97 spin_lock(&sh03_rtc_lock); 98 for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */ 99 if (!(__raw_readb(RTC_CTL) & RTC_BUSY)) 100 break; 101 cmos_minutes = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10; 102 real_seconds = tm->tm_sec; 103 real_minutes = tm->tm_min; 104 if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1) 105 real_minutes += 30; /* correct for half hour time zone */ 106 real_minutes %= 60; 107 108 if (abs(real_minutes - cmos_minutes) < 30) { 109 __raw_writeb(real_seconds % 10, RTC_SEC1); 110 __raw_writeb(real_seconds / 10, RTC_SEC10); 111 __raw_writeb(real_minutes % 10, RTC_MIN1); 112 __raw_writeb(real_minutes / 10, RTC_MIN10); 113 } else { 114 printk_once(KERN_NOTICE 115 "set_rtc_mmss: can't update from %d to %d\n", 116 cmos_minutes, real_minutes); 117 retval = -EINVAL; 118 } 119 spin_unlock(&sh03_rtc_lock); 120 121 return retval; 122 } 123 124 int sh03_rtc_settimeofday(struct device *dev, struct rtc_time *tm) 125 { 126 return set_rtc_mmss(tm); 127 } 128 129 static const struct rtc_class_ops rtc_generic_ops = { 130 .read_time = sh03_rtc_gettimeofday, 131 .set_time = sh03_rtc_settimeofday, 132 }; 133 134 static int __init sh03_time_init(void) 135 { 136 struct platform_device *pdev; 137 138 pdev = platform_device_register_data(NULL, "rtc-generic", -1, 139 &rtc_generic_ops, 140 sizeof(rtc_generic_ops)); 141 142 return PTR_ERR_OR_ZERO(pdev); 143 } 144 arch_initcall(sh03_time_init); 145