Initial commit: OpenHarmony-v4.0-ReleaseOpenHarmony-v4.0-Release

1 files changed, 172 insertions, 0 deletions

diff --git a/arch/mips/dec/time.c b/arch/mips/dec/time.c
new file mode 100644
index 000000000..c38686f89
--- /dev/null
+++ b/arch/mips/dec/time.c
@@ -0,0 +1,172 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ *  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/init.h>
+#include <linux/mc146818rtc.h>
+#include <linux/param.h>
+
+#include <asm/cpu-features.h>
+#include <asm/ds1287.h>
+#include <asm/time.h>
+#include <asm/dec/interrupts.h>
+#include <asm/dec/ioasic.h>
+#include <asm/dec/machtype.h>
+
+void read_persistent_clock64(struct timespec64 *ts)
+{
+        unsigned int year, mon, day, hour, min, sec, real_year;
+        unsigned long flags;
+
+        spin_lock_irqsave(&rtc_lock, flags);
+
+        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);
+                /*
+                 * 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);
+        } while (sec != CMOS_READ(RTC_SECONDS));
+
+        spin_unlock_irqrestore(&rtc_lock, flags);
+
+        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);
+        }
+
+        year += real_year - 72 + 2000;
+
+        ts->tv_sec = mktime64(year, mon, day, hour, min, sec);
+        ts->tv_nsec = 0;
+}
+
+/*
+ * In order to set the CMOS clock precisely, update_persistent_clock64 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.
+ */
+int update_persistent_clock64(struct timespec64 now)
+{
+        time64_t nowtime = now.tv_sec;
+        int retval = 0;
+        int real_seconds, real_minutes, cmos_minutes;
+        unsigned char save_control, save_freq_select;
+
+        /* irq are locally disabled here */
+        spin_lock(&rtc_lock);
+        /* 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_minutes = div_s64_rem(nowtime, 60, &real_seconds);
+        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_once(KERN_NOTICE
+                       "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);
+        spin_unlock(&rtc_lock);
+
+        return retval;
+}
+
+void __init plat_time_init(void)
+{
+        int ioasic_clock = 0;
+        u32 start, end;
+        int i = HZ / 8;
+
+        /* Set up the rate of periodic DS1287 interrupts. */
+        ds1287_set_base_clock(HZ);
+
+        /* On some I/O ASIC systems we have the I/O ASIC's counter.  */
+        if (IOASIC)
+                ioasic_clock = dec_ioasic_clocksource_init() == 0;
+        if (cpu_has_counter) {
+                ds1287_timer_state();
+                while (!ds1287_timer_state())
+                        ;
+
+                start = read_c0_count();
+
+                while (i--)
+                        while (!ds1287_timer_state())
+                                ;
+
+                end = read_c0_count();
+
+                mips_hpt_frequency = (end - start) * 8;
+                printk(KERN_INFO "MIPS counter frequency %dHz\n",
+                        mips_hpt_frequency);
+
+                /*
+                 * All R4k DECstations suffer from the CP0 Count erratum,
+                 * so we can't use the timer as a clock source, and a clock
+                 * event both at a time.  An accurate wall clock is more
+                 * important than a high-precision interval timer so only
+                 * use the timer as a clock source, and not a clock event
+                 * if there's no I/O ASIC counter available to serve as a
+                 * clock source.
+                 */
+                if (!ioasic_clock) {
+                        init_r4k_clocksource();
+                        mips_hpt_frequency = 0;
+                }
+        }
+
+        ds1287_clockevent_init(dec_interrupt[DEC_IRQ_RTC]);
+}