LXR linux/arch/sh/boards/mach-sh03/rtc.c

   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
  39static DEFINE_SPINLOCK(sh03_rtc_lock);
  40
  41static 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
  89static 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
 123int sh03_rtc_settimeofday(struct device *dev, struct rtc_time *tm)
 124{
 125        return set_rtc_mmss(tm);
 126}
 127
 128static const struct rtc_class_ops rtc_generic_ops = {
 129        .read_time = sh03_rtc_gettimeofday,
 130        .set_time = sh03_rtc_settimeofday,
 131};
 132
 133static 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}
 143arch_initcall(sh03_time_init);
 144