1 files changed, 200 insertions, 0 deletions

diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
new file mode 100644
index 000000000000..dc7091caa7aa
--- /dev/null
+++ b/arch/mips/dec/time.c
@@ -0,0 +1,200 @@
+/*
+ *  linux/arch/mips/dec/time.c
+ *
+ *  Copyright (C) 1991, 1992, 1995  Linus Torvalds
+ *  Copyright (C) 2000, 2003  Maciej W. Rozycki
+ *
+ * This file contains the time handling details for PC-style clocks as
+ * found in some MIPS systems.
+ *
+ */
+#include <linux/bcd.h>
+#include <linux/errno.h>
+#include <linux/init.h>
+#include <linux/interrupt.h>
+#include <linux/kernel.h>
+#include <linux/mc146818rtc.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/param.h>
+#include <linux/sched.h>
+#include <linux/string.h>
+#include <linux/time.h>
+#include <linux/types.h>
+
+#include <asm/bootinfo.h>
+#include <asm/cpu.h>
+#include <asm/div64.h>
+#include <asm/io.h>
+#include <asm/irq.h>
+#include <asm/mipsregs.h>
+#include <asm/sections.h>
+#include <asm/time.h>
+
+#include <asm/dec/interrupts.h>
+#include <asm/dec/ioasic.h>
+#include <asm/dec/ioasic_addrs.h>
+#include <asm/dec/machtype.h>
+
+
+static unsigned long dec_rtc_get_time(void)
+{
+        unsigned int year, mon, day, hour, min, sec, real_year;
+        int i;
+
+        /* The Linux interpretation of the DS1287 clock register contents:
+         * When the Update-In-Progress (UIP) flag goes from 1 to 0, the
+         * RTC registers show the second which has precisely just started.
+         * Let's hope other operating systems interpret the RTC the same way.
+         */
+        /* read RTC exactly on falling edge of update flag */
+        for (i = 0; i < 1000000; i++)   /* may take up to 1 second... */
+                if (CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP)
+                        break;
+        for (i = 0; i < 1000000; i++)   /* must try at least 2.228 ms */
+                if (!(CMOS_READ(RTC_FREQ_SELECT) & RTC_UIP))
+                        break;
+        /* Isn't this overkill?  UIP above should guarantee consistency */
+        do {
+                sec = CMOS_READ(RTC_SECONDS);
+                min = CMOS_READ(RTC_MINUTES);
+                hour = CMOS_READ(RTC_HOURS);
+                day = CMOS_READ(RTC_DAY_OF_MONTH);
+                mon = CMOS_READ(RTC_MONTH);
+                year = CMOS_READ(RTC_YEAR);
+        } while (sec != CMOS_READ(RTC_SECONDS));
+        if (!(CMOS_READ(RTC_CONTROL) & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+                sec = BCD2BIN(sec);
+                min = BCD2BIN(min);
+                hour = BCD2BIN(hour);
+                day = BCD2BIN(day);
+                mon = BCD2BIN(mon);
+                year = BCD2BIN(year);
+        }
+        /*
+         * The PROM will reset the year to either '72 or '73.
+         * Therefore we store the real year separately, in one
+         * of unused BBU RAM locations.
+         */
+        real_year = CMOS_READ(RTC_DEC_YEAR);
+        year += real_year - 72 + 2000;
+
+        return mktime(year, mon, day, hour, min, sec);
+}
+
+/*
+ * In order to set the CMOS clock precisely, dec_rtc_set_mmss has to
+ * be called 500 ms after the second nowtime has started, because when
+ * nowtime is written into the registers of the CMOS clock, it will
+ * jump to the next second precisely 500 ms later.  Check the Dallas
+ * DS1287 data sheet for details.
+ */
+static int dec_rtc_set_mmss(unsigned long nowtime)
+{
+        int retval = 0;
+        int real_seconds, real_minutes, cmos_minutes;
+        unsigned char save_control, save_freq_select;
+
+        /* tell the clock it's being set */
+        save_control = CMOS_READ(RTC_CONTROL);
+        CMOS_WRITE((save_control | RTC_SET), RTC_CONTROL);
+
+        /* stop and reset prescaler */
+        save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
+        CMOS_WRITE((save_freq_select | RTC_DIV_RESET2), RTC_FREQ_SELECT);
+
+        cmos_minutes = CMOS_READ(RTC_MINUTES);
+        if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD)
+                cmos_minutes = BCD2BIN(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 = nowtime % 60;
+        real_minutes = nowtime / 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) {
+                if (!(save_control & RTC_DM_BINARY) || RTC_ALWAYS_BCD) {
+                        real_seconds = BIN2BCD(real_seconds);
+                        real_minutes = BIN2BCD(real_minutes);
+                }
+                CMOS_WRITE(real_seconds, RTC_SECONDS);
+                CMOS_WRITE(real_minutes, RTC_MINUTES);
+        } else {
+                printk(KERN_WARNING
+                       "set_rtc_mmss: can't update from %d to %d\n",
+                       cmos_minutes, real_minutes);
+                retval = -1;
+        }
+
+        /* The following flags have to be released exactly in this order,
+         * otherwise the DS1287 will not reset the oscillator and will not
+         * update precisely 500 ms later.  You won't find this mentioned
+         * in the Dallas Semiconductor data sheets, but who believes data
+         * sheets anyway ...                           -- Markus Kuhn
+         */
+        CMOS_WRITE(save_control, RTC_CONTROL);
+        CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
+
+        return retval;
+}
+
+
+static int dec_timer_state(void)
+{
+        return (CMOS_READ(RTC_REG_C) & RTC_PF) != 0;
+}
+
+static void dec_timer_ack(void)
+{
+        CMOS_READ(RTC_REG_C);                   /* Ack the RTC interrupt.  */
+}
+
+static unsigned int dec_ioasic_hpt_read(void)
+{
+        /*
+         * The free-running counter is 32-bit which is good for about
+         * 2 minutes, 50 seconds at possible count rates of up to 25MHz.
+         */
+        return ioasic_read(IO_REG_FCTR);
+}
+
+static void dec_ioasic_hpt_init(unsigned int count)
+{
+        ioasic_write(IO_REG_FCTR, ioasic_read(IO_REG_FCTR) - count);
+}
+
+
+void __init dec_time_init(void)
+{
+        rtc_get_time = dec_rtc_get_time;
+        rtc_set_mmss = dec_rtc_set_mmss;
+
+        mips_timer_state = dec_timer_state;
+        mips_timer_ack = dec_timer_ack;
+
+        if (!cpu_has_counter && IOASIC) {
+                /* For pre-R4k systems we use the I/O ASIC's counter.  */
+                mips_hpt_read = dec_ioasic_hpt_read;
+                mips_hpt_init = dec_ioasic_hpt_init;
+        }
+
+        /* Set up the rate of periodic DS1287 interrupts.  */
+        CMOS_WRITE(RTC_REF_CLCK_32KHZ | (16 - LOG_2_HZ), RTC_REG_A);
+}
+
+EXPORT_SYMBOL(do_settimeofday);
+
+void __init dec_timer_setup(struct irqaction *irq)
+{
+        setup_irq(dec_interrupt[DEC_IRQ_RTC], irq);
+
+        /* Enable periodic DS1287 interrupts.  */
+        CMOS_WRITE(CMOS_READ(RTC_REG_B) | RTC_PIE, RTC_REG_B);
+}