summaryrefslogtreecommitdiff
path: root/arch/sh/kernel/cpu/rtc.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/sh/kernel/cpu/rtc.c')
-rw-r--r--arch/sh/kernel/cpu/rtc.c136
1 files changed, 136 insertions, 0 deletions
diff --git a/arch/sh/kernel/cpu/rtc.c b/arch/sh/kernel/cpu/rtc.c
new file mode 100644
index 000000000000..f8361f5e788b
--- /dev/null
+++ b/arch/sh/kernel/cpu/rtc.c
@@ -0,0 +1,136 @@
+/*
+ * linux/arch/sh/kernel/rtc.c -- SH3 / SH4 on-chip RTC support
+ *
+ * Copyright (C) 2000 Philipp Rumpf <prumpf@tux.org>
+ * Copyright (C) 1999 Tetsuya Okada & Niibe Yutaka
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/time.h>
+
+#include <asm/io.h>
+#include <asm/rtc.h>
+
+#ifndef BCD_TO_BIN
+#define BCD_TO_BIN(val) ((val)=((val)&15) + ((val)>>4)*10)
+#endif
+
+#ifndef BIN_TO_BCD
+#define BIN_TO_BCD(val) ((val)=(((val)/10)<<4) + (val)%10)
+#endif
+
+void sh_rtc_gettimeofday(struct timespec *ts)
+{
+ unsigned int sec128, sec, sec2, min, hr, wk, day, mon, yr, yr100, cf_bit;
+ unsigned long flags;
+
+ again:
+ do {
+ local_irq_save(flags);
+ ctrl_outb(0, RCR1); /* Clear CF-bit */
+ sec128 = ctrl_inb(R64CNT);
+ sec = ctrl_inb(RSECCNT);
+ min = ctrl_inb(RMINCNT);
+ hr = ctrl_inb(RHRCNT);
+ wk = ctrl_inb(RWKCNT);
+ day = ctrl_inb(RDAYCNT);
+ mon = ctrl_inb(RMONCNT);
+#if defined(CONFIG_CPU_SH4)
+ yr = ctrl_inw(RYRCNT);
+ yr100 = (yr >> 8);
+ yr &= 0xff;
+#else
+ yr = ctrl_inb(RYRCNT);
+ yr100 = (yr == 0x99) ? 0x19 : 0x20;
+#endif
+ sec2 = ctrl_inb(R64CNT);
+ cf_bit = ctrl_inb(RCR1) & RCR1_CF;
+ local_irq_restore(flags);
+ } while (cf_bit != 0 || ((sec128 ^ sec2) & RTC_BIT_INVERTED) != 0);
+
+ BCD_TO_BIN(yr100);
+ BCD_TO_BIN(yr);
+ BCD_TO_BIN(mon);
+ BCD_TO_BIN(day);
+ BCD_TO_BIN(hr);
+ BCD_TO_BIN(min);
+ BCD_TO_BIN(sec);
+
+ if (yr > 99 || mon < 1 || mon > 12 || day > 31 || day < 1 ||
+ hr > 23 || min > 59 || sec > 59) {
+ printk(KERN_ERR
+ "SH RTC: invalid value, resetting to 1 Jan 2000\n");
+ local_irq_save(flags);
+ ctrl_outb(RCR2_RESET, RCR2); /* Reset & Stop */
+ ctrl_outb(0, RSECCNT);
+ ctrl_outb(0, RMINCNT);
+ ctrl_outb(0, RHRCNT);
+ ctrl_outb(6, RWKCNT);
+ ctrl_outb(1, RDAYCNT);
+ ctrl_outb(1, RMONCNT);
+#if defined(CONFIG_CPU_SH4)
+ ctrl_outw(0x2000, RYRCNT);
+#else
+ ctrl_outb(0, RYRCNT);
+#endif
+ ctrl_outb(RCR2_RTCEN|RCR2_START, RCR2); /* Start */
+ goto again;
+ }
+
+#if RTC_BIT_INVERTED != 0
+ if ((sec128 & RTC_BIT_INVERTED))
+ sec--;
+#endif
+
+ ts->tv_sec = mktime(yr100 * 100 + yr, mon, day, hr, min, sec);
+ ts->tv_nsec = ((sec128 * 1000000) / 128) * 1000;
+}
+
+/*
+ * Changed to only care about tv_sec, and not the full timespec struct
+ * (i.e. tv_nsec). It can easily be switched to timespec for future cpus
+ * that support setting usec or nsec RTC values.
+ */
+int sh_rtc_settimeofday(const time_t secs)
+{
+ int retval = 0;
+ int real_seconds, real_minutes, cmos_minutes;
+ unsigned long flags;
+
+ local_irq_save(flags);
+ ctrl_outb(RCR2_RESET, RCR2); /* Reset pre-scaler & stop RTC */
+
+ cmos_minutes = ctrl_inb(RMINCNT);
+ BCD_TO_BIN(cmos_minutes);
+
+ /*
+ * since we're only adjusting minutes and seconds,
+ * don't interfere with hour overflow. This avoids
+ * messing with unknown time zones but requires your
+ * RTC not to be off by more than 15 minutes
+ */
+ real_seconds = secs % 60;
+ real_minutes = secs / 60;
+ 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) {
+ BIN_TO_BCD(real_seconds);
+ BIN_TO_BCD(real_minutes);
+ ctrl_outb(real_seconds, RSECCNT);
+ ctrl_outb(real_minutes, RMINCNT);
+ } else {
+ printk(KERN_WARNING
+ "set_rtc_time: can't update from %d to %d\n",
+ cmos_minutes, real_minutes);
+ retval = -1;
+ }
+
+ ctrl_outb(RCR2_RTCEN|RCR2_START, RCR2); /* Start RTC */
+ local_irq_restore(flags);
+
+ return retval;
+}