linux/linux-5.4.31/arch/sh/boards/mach-sh03/rtc.c

145 lines
4.3 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* linux/arch/sh/boards/sh03/rtc.c -- CTP/PCI-SH03 on-chip RTC support
*
* Copyright (C) 2004 Saito.K & Jeanne(ksaito@interface.co.jp)
*
*/
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/time.h>
#include <linux/bcd.h>
#include <linux/rtc.h>
#include <linux/spinlock.h>
#include <linux/io.h>
#include <linux/rtc.h>
#include <linux/platform_device.h>
#define RTC_BASE 0xb0000000
#define RTC_SEC1 (RTC_BASE + 0)
#define RTC_SEC10 (RTC_BASE + 1)
#define RTC_MIN1 (RTC_BASE + 2)
#define RTC_MIN10 (RTC_BASE + 3)
#define RTC_HOU1 (RTC_BASE + 4)
#define RTC_HOU10 (RTC_BASE + 5)
#define RTC_WEE1 (RTC_BASE + 6)
#define RTC_DAY1 (RTC_BASE + 7)
#define RTC_DAY10 (RTC_BASE + 8)
#define RTC_MON1 (RTC_BASE + 9)
#define RTC_MON10 (RTC_BASE + 10)
#define RTC_YEA1 (RTC_BASE + 11)
#define RTC_YEA10 (RTC_BASE + 12)
#define RTC_YEA100 (RTC_BASE + 13)
#define RTC_YEA1000 (RTC_BASE + 14)
#define RTC_CTL (RTC_BASE + 15)
#define RTC_BUSY 1
#define RTC_STOP 2
static DEFINE_SPINLOCK(sh03_rtc_lock);
static int sh03_rtc_gettimeofday(struct device *dev, struct rtc_time *tm)
{
unsigned int year, mon, day, hour, min, sec;
spin_lock(&sh03_rtc_lock);
again:
do {
sec = (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10;
min = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
hour = (__raw_readb(RTC_HOU1) & 0xf) + (__raw_readb(RTC_HOU10) & 0xf) * 10;
day = (__raw_readb(RTC_DAY1) & 0xf) + (__raw_readb(RTC_DAY10) & 0xf) * 10;
mon = (__raw_readb(RTC_MON1) & 0xf) + (__raw_readb(RTC_MON10) & 0xf) * 10;
year = (__raw_readb(RTC_YEA1) & 0xf) + (__raw_readb(RTC_YEA10) & 0xf) * 10
+ (__raw_readb(RTC_YEA100 ) & 0xf) * 100
+ (__raw_readb(RTC_YEA1000) & 0xf) * 1000;
} while (sec != (__raw_readb(RTC_SEC1) & 0xf) + (__raw_readb(RTC_SEC10) & 0x7) * 10);
if (year == 0 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
hour > 23 || min > 59 || sec > 59) {
printk(KERN_ERR
"SH-03 RTC: invalid value, resetting to 1 Jan 2000\n");
printk("year=%d, mon=%d, day=%d, hour=%d, min=%d, sec=%d\n",
year, mon, day, hour, min, sec);
__raw_writeb(0, RTC_SEC1); __raw_writeb(0, RTC_SEC10);
__raw_writeb(0, RTC_MIN1); __raw_writeb(0, RTC_MIN10);
__raw_writeb(0, RTC_HOU1); __raw_writeb(0, RTC_HOU10);
__raw_writeb(6, RTC_WEE1);
__raw_writeb(1, RTC_DAY1); __raw_writeb(0, RTC_DAY10);
__raw_writeb(1, RTC_MON1); __raw_writeb(0, RTC_MON10);
__raw_writeb(0, RTC_YEA1); __raw_writeb(0, RTC_YEA10);
__raw_writeb(0, RTC_YEA100);
__raw_writeb(2, RTC_YEA1000);
__raw_writeb(0, RTC_CTL);
goto again;
}
spin_unlock(&sh03_rtc_lock);
tm->tm_sec = sec;
tm->tm_min = min;
tm->tm_hour = hour;
tm->tm_mday = day;
tm->tm_mon = mon;
tm->tm_year = year - 1900;
return 0;
}
static int set_rtc_mmss(struct rtc_time *tm)
{
int retval = 0;
int real_seconds, real_minutes, cmos_minutes;
int i;
/* gets recalled with irq locally disabled */
spin_lock(&sh03_rtc_lock);
for (i = 0 ; i < 1000000 ; i++) /* may take up to 1 second... */
if (!(__raw_readb(RTC_CTL) & RTC_BUSY))
break;
cmos_minutes = (__raw_readb(RTC_MIN1) & 0xf) + (__raw_readb(RTC_MIN10) & 0xf) * 10;
real_seconds = tm->tm_sec;
real_minutes = tm->tm_min;
if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
real_minutes += 30; /* correct for half hour time zone */
real_minutes %= 60;
if (abs(real_minutes - cmos_minutes) < 30) {
__raw_writeb(real_seconds % 10, RTC_SEC1);
__raw_writeb(real_seconds / 10, RTC_SEC10);
__raw_writeb(real_minutes % 10, RTC_MIN1);
__raw_writeb(real_minutes / 10, RTC_MIN10);
} else {
printk_once(KERN_NOTICE
"set_rtc_mmss: can't update from %d to %d\n",
cmos_minutes, real_minutes);
retval = -EINVAL;
}
spin_unlock(&sh03_rtc_lock);
return retval;
}
int sh03_rtc_settimeofday(struct device *dev, struct rtc_time *tm)
{
return set_rtc_mmss(tm);
}
static const struct rtc_class_ops rtc_generic_ops = {
.read_time = sh03_rtc_gettimeofday,
.set_time = sh03_rtc_settimeofday,
};
static int __init sh03_time_init(void)
{
struct platform_device *pdev;
pdev = platform_device_register_data(NULL, "rtc-generic", -1,
&rtc_generic_ops,
sizeof(rtc_generic_ops));
return PTR_ERR_OR_ZERO(pdev);
}
arch_initcall(sh03_time_init);