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