2 * linux/arch/sh/kernel/rtc.c -- SH3 / SH4 on-chip RTC support
4 * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
5 * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
8 #include <linux/init.h>
9 #include <linux/kernel.h>
10 #include <linux/sched.h>
11 #include <linux/time.h>
17 #define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
21 #define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)
24 void sh_rtc_gettimeofday(struct timespec *ts)
26 unsigned int sec128, sec, sec2, min, hr, wk, day, mon, yr, yr100, cf_bit;
31 local_irq_save(flags);
32 ctrl_outb(0, RCR1); /* Clear CF-bit */
33 sec128 = ctrl_inb(R64CNT);
34 sec = ctrl_inb(RSECCNT);
35 min = ctrl_inb(RMINCNT);
36 hr = ctrl_inb(RHRCNT);
37 wk = ctrl_inb(RWKCNT);
38 day = ctrl_inb(RDAYCNT);
39 mon = ctrl_inb(RMONCNT);
40 #if defined(CONFIG_CPU_SH4)
41 yr = ctrl_inw(RYRCNT);
45 yr = ctrl_inb(RYRCNT);
46 yr100 = (yr == 0x99) ? 0x19 : 0x20;
48 sec2 = ctrl_inb(R64CNT);
49 cf_bit = ctrl_inb(RCR1) & RCR1_CF;
50 local_irq_restore(flags);
51 } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
61 if (yr > 99 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
62 hr > 23 || min > 59 || sec > 59) {
64 "SH RTC: invalid value, resetting to 1 Jan 2000\n");
65 local_irq_save(flags);
66 ctrl_outb(RCR2_RESET, RCR2); /* Reset & Stop */
67 ctrl_outb(0, RSECCNT);
68 ctrl_outb(0, RMINCNT);
71 ctrl_outb(1, RDAYCNT);
72 ctrl_outb(1, RMONCNT);
73 #if defined(CONFIG_CPU_SH4)
74 ctrl_outw(0x2000, RYRCNT);
78 ctrl_outb(RCR2_RTCEN|RCR2_START, RCR2); /* Start */
82 #if RTC_BIT_INVERTED != 0
83 if ((sec128 & RTC_BIT_INVERTED))
87 ts->tv_sec = mktime(yr100 * 100 + yr, mon, day, hr, min, sec);
88 ts->tv_nsec = ((sec128 * 1000000) / 128) * 1000;
92 * Changed to only care about tv_sec, and not the full timespec struct
93 * (i.e. tv_nsec). It can easily be switched to timespec for future cpus
94 * that support setting usec or nsec RTC values.
96 int sh_rtc_settimeofday(const time_t secs)
99 int real_seconds, real_minutes, cmos_minutes;
102 local_irq_save(flags);
103 ctrl_outb(RCR2_RESET, RCR2); /* Reset pre-scaler & stop RTC */
105 cmos_minutes = ctrl_inb(RMINCNT);
106 BCD_TO_BIN(cmos_minutes);
109 * since we're only adjusting minutes and seconds,
110 * don't interfere with hour overflow. This avoids
111 * messing with unknown time zones but requires your
112 * RTC not to be off by more than 15 minutes
114 real_seconds = secs % 60;
115 real_minutes = secs / 60;
116 if (((abs(real_minutes - cmos_minutes) + 15)/30) & 1)
117 real_minutes += 30; /* correct for half hour time zone */
120 if (abs(real_minutes - cmos_minutes) < 30) {
121 BIN_TO_BCD(real_seconds);
122 BIN_TO_BCD(real_minutes);
123 ctrl_outb(real_seconds, RSECCNT);
124 ctrl_outb(real_minutes, RMINCNT);
127 "set_rtc_time: can't update from %d to %d\n",
128 cmos_minutes, real_minutes);
132 ctrl_outb(RCR2_RTCEN|RCR2_START, RCR2); /* Start RTC */
133 local_irq_restore(flags);