hw/rtc/ls7a_rtc.c - qemu - Git at Google

 /* SPDX-License-Identifier: GPL-2.0-or-later */
 /*
  * Loongarch LS7A Real Time Clock emulation
  *
  * Copyright (C) 2021 Loongson Technology Corporation Limited
  */

 #include "qemu/osdep.h"
 #include "hw/sysbus.h"
 #include "hw/irq.h"
 #include "include/hw/register.h"
 #include "qemu/timer.h"
 #include "sysemu/sysemu.h"
 #include "qemu/cutils.h"
 #include "qemu/log.h"
 #include "migration/vmstate.h"
 #include "hw/misc/unimp.h"
 #include "sysemu/rtc.h"
 #include "hw/registerfields.h"

 #define SYS_TOYTRIM        0x20
 #define SYS_TOYWRITE0      0x24
 #define SYS_TOYWRITE1      0x28
 #define SYS_TOYREAD0       0x2C
 #define SYS_TOYREAD1       0x30
 #define SYS_TOYMATCH0      0x34
 #define SYS_TOYMATCH1      0x38
 #define SYS_TOYMATCH2      0x3C
 #define SYS_RTCCTRL        0x40
 #define SYS_RTCTRIM        0x60
 #define SYS_RTCWRTIE0      0x64
 #define SYS_RTCREAD0       0x68
 #define SYS_RTCMATCH0      0x6C
 #define SYS_RTCMATCH1      0x70
 #define SYS_RTCMATCH2      0x74

 #define LS7A_RTC_FREQ     32768
 #define TIMER_NUMS        3
 /*
  * Shift bits and filed mask
  */

 FIELD(TOY, MON, 26, 6)
 FIELD(TOY, DAY, 21, 5)
 FIELD(TOY, HOUR, 16, 5)
 FIELD(TOY, MIN, 10, 6)
 FIELD(TOY, SEC, 4, 6)
 FIELD(TOY, MSEC, 0, 4)

 FIELD(TOY_MATCH, YEAR, 26, 6)
 FIELD(TOY_MATCH, MON, 22, 4)
 FIELD(TOY_MATCH, DAY, 17, 5)
 FIELD(TOY_MATCH, HOUR, 12, 5)
 FIELD(TOY_MATCH, MIN, 6, 6)
 FIELD(TOY_MATCH, SEC, 0, 6)

 FIELD(RTC_CTRL, RTCEN, 13, 1)
 FIELD(RTC_CTRL, TOYEN, 11, 1)
 FIELD(RTC_CTRL, EO, 8, 1)

 #define TYPE_LS7A_RTC "ls7a_rtc"
 OBJECT_DECLARE_SIMPLE_TYPE(LS7ARtcState, LS7A_RTC)

 struct LS7ARtcState {
     SysBusDevice parent_obj;

     MemoryRegion iomem;
     /*
      * Needed to preserve the tick_count across migration, even if the
      * absolute value of the rtc_clock is different on the source and
      * destination.
      */
     int64_t offset_toy;
     int64_t offset_rtc;
     int64_t data;
     int tidx;
     uint32_t toymatch[3];
     uint32_t toytrim;
     uint32_t cntrctl;
     uint32_t rtctrim;
     uint32_t rtccount;
     uint32_t rtcmatch[3];
     QEMUTimer *toy_timer[TIMER_NUMS];
     QEMUTimer *rtc_timer[TIMER_NUMS];
     qemu_irq irq;
 };

 /* switch nanoseconds time to rtc ticks */
 static uint64_t ls7a_rtc_ticks(void)
 {
     return qemu_clock_get_ns(rtc_clock) * LS7A_RTC_FREQ / NANOSECONDS_PER_SECOND;
 }

 /* switch rtc ticks to nanoseconds */
 static uint64_t ticks_to_ns(uint64_t ticks)
 {
     return ticks * NANOSECONDS_PER_SECOND / LS7A_RTC_FREQ;
 }

 static bool toy_enabled(LS7ARtcState *s)
 {
     return FIELD_EX32(s->cntrctl, RTC_CTRL, TOYEN) &&
            FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
 }

 static bool rtc_enabled(LS7ARtcState *s)
 {
     return FIELD_EX32(s->cntrctl, RTC_CTRL, RTCEN) &&
            FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
 }

 /* parse struct tm to toy value */
 static uint64_t toy_time_to_val_mon(const struct tm *tm)
 {
     uint64_t val = 0;

     val = FIELD_DP32(val, TOY, MON, tm->tm_mon + 1);
     val = FIELD_DP32(val, TOY, DAY, tm->tm_mday);
     val = FIELD_DP32(val, TOY, HOUR, tm->tm_hour);
     val = FIELD_DP32(val, TOY, MIN, tm->tm_min);
     val = FIELD_DP32(val, TOY, SEC, tm->tm_sec);
     return val;
 }

 static void toymatch_val_to_time(LS7ARtcState *s, uint64_t val, struct tm *tm)
 {
     qemu_get_timedate(tm, s->offset_toy);
     tm->tm_sec = FIELD_EX32(val, TOY_MATCH, SEC);
     tm->tm_min = FIELD_EX32(val, TOY_MATCH, MIN);
     tm->tm_hour = FIELD_EX32(val, TOY_MATCH, HOUR);
     tm->tm_mday = FIELD_EX32(val, TOY_MATCH, DAY);
     tm->tm_mon = FIELD_EX32(val, TOY_MATCH, MON) - 1;
     tm->tm_year += (FIELD_EX32(val, TOY_MATCH, YEAR) - (tm->tm_year & 0x3f));
 }

 static void toymatch_write(LS7ARtcState *s, uint64_t val, int num)
 {
     int64_t now, expire_time;
     struct tm tm = {};

     /* it do not support write when toy disabled */
     if (toy_enabled(s)) {
         s->toymatch[num] = val;
         /* calculate expire time */
         now = qemu_clock_get_ms(rtc_clock);
         toymatch_val_to_time(s, val, &tm);
         expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
         timer_mod(s->toy_timer[num], expire_time);
     }
 }

 static void rtcmatch_write(LS7ARtcState *s, uint64_t val, int num)
 {
     uint64_t expire_ns;

     /* it do not support write when toy disabled */
     if (rtc_enabled(s)) {
         s->rtcmatch[num] = val;
         /* calculate expire time */
         expire_ns = ticks_to_ns(val) - ticks_to_ns(s->offset_rtc);
         timer_mod_ns(s->rtc_timer[num], expire_ns);
     }
 }

 static void ls7a_toy_stop(LS7ARtcState *s)
 {
     int i;

     /* delete timers, and when re-enabled, recalculate expire time */
     for (i = 0; i < TIMER_NUMS; i++) {
         timer_del(s->toy_timer[i]);
     }
 }

 static void ls7a_rtc_stop(LS7ARtcState *s)
 {
     int i;

     /* delete timers, and when re-enabled, recalculate expire time */
     for (i = 0; i < TIMER_NUMS; i++) {
         timer_del(s->rtc_timer[i]);
     }
 }

 static void ls7a_toy_start(LS7ARtcState *s)
 {
     int i;
     uint64_t expire_time, now;
     struct tm tm = {};

     now = qemu_clock_get_ms(rtc_clock);

     /* recalculate expire time and enable timer */
     for (i = 0; i < TIMER_NUMS; i++) {
         toymatch_val_to_time(s, s->toymatch[i], &tm);
         expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
         timer_mod(s->toy_timer[i], expire_time);
     }
 }

 static void ls7a_rtc_start(LS7ARtcState *s)
 {
     int i;
     uint64_t expire_time;

     /* recalculate expire time and enable timer */
     for (i = 0; i < TIMER_NUMS; i++) {
         expire_time = ticks_to_ns(s->rtcmatch[i]) - ticks_to_ns(s->offset_rtc);
         timer_mod_ns(s->rtc_timer[i], expire_time);
     }
 }

 static uint64_t ls7a_rtc_read(void *opaque, hwaddr addr, unsigned size)
 {
     LS7ARtcState *s = LS7A_RTC(opaque);
     struct tm tm;
     int val = 0;

     switch (addr) {
     case SYS_TOYREAD0:
         if (toy_enabled(s)) {
             qemu_get_timedate(&tm, s->offset_toy);
             val = toy_time_to_val_mon(&tm);
         } else {
             /* return 0 when toy disabled */
             val = 0;
         }
         break;
     case SYS_TOYREAD1:
         if (toy_enabled(s)) {
             qemu_get_timedate(&tm, s->offset_toy);
             val = tm.tm_year;
         } else {
             /* return 0 when toy disabled */
             val = 0;
         }
         break;
     case SYS_TOYMATCH0:
         val = s->toymatch[0];
         break;
     case SYS_TOYMATCH1:
         val = s->toymatch[1];
         break;
     case SYS_TOYMATCH2:
         val = s->toymatch[2];
         break;
     case SYS_RTCCTRL:
         val = s->cntrctl;
         break;
     case SYS_RTCREAD0:
         if (rtc_enabled(s)) {
             val = ls7a_rtc_ticks() + s->offset_rtc;
         } else {
             /* return 0 when rtc disabled */
             val = 0;
         }
         break;
     case SYS_RTCMATCH0:
         val = s->rtcmatch[0];
         break;
     case SYS_RTCMATCH1:
         val = s->rtcmatch[1];
         break;
     case SYS_RTCMATCH2:
         val = s->rtcmatch[2];
         break;
     default:
         val = 0;
         break;
     }
     return val;
 }

 static void ls7a_rtc_write(void *opaque, hwaddr addr,
                            uint64_t val, unsigned size)
 {
     int old_toyen, old_rtcen, new_toyen, new_rtcen;
     LS7ARtcState *s = LS7A_RTC(opaque);
     struct tm tm;

     switch (addr) {
     case SYS_TOYWRITE0:
         /* it do not support write when toy disabled */
         if (toy_enabled(s)) {
             qemu_get_timedate(&tm, s->offset_toy);
             tm.tm_sec = FIELD_EX32(val, TOY, SEC);
             tm.tm_min = FIELD_EX32(val, TOY, MIN);
             tm.tm_hour = FIELD_EX32(val, TOY, HOUR);
             tm.tm_mday = FIELD_EX32(val, TOY, DAY);
             tm.tm_mon = FIELD_EX32(val, TOY, MON) - 1;
             s->offset_toy = qemu_timedate_diff(&tm);
         }
     break;
     case SYS_TOYWRITE1:
         if (toy_enabled(s)) {
             qemu_get_timedate(&tm, s->offset_toy);
             tm.tm_year = val;
             s->offset_toy = qemu_timedate_diff(&tm);
         }
         break;
     case SYS_TOYMATCH0:
         toymatch_write(s, val, 0);
         break;
     case SYS_TOYMATCH1:
         toymatch_write(s, val, 1);
         break;
     case SYS_TOYMATCH2:
         toymatch_write(s, val, 2);
         break;
     case SYS_RTCCTRL:
         /* get old ctrl */
         old_toyen = toy_enabled(s);
         old_rtcen = rtc_enabled(s);

         s->cntrctl = val;
         /* get new ctrl */
         new_toyen = toy_enabled(s);
         new_rtcen = rtc_enabled(s);

         /*
          * we do not consider if EO changed, as it always set at most time.
          * toy or rtc enabled should start timer. otherwise, stop timer
          */
         if (old_toyen != new_toyen) {
             if (new_toyen) {
                 ls7a_toy_start(s);
             } else {
                 ls7a_toy_stop(s);
             }
         }
         if (old_rtcen != new_rtcen) {
             if (new_rtcen) {
                 ls7a_rtc_start(s);
             } else {
                 ls7a_rtc_stop(s);
             }
         }
         break;
     case SYS_RTCWRTIE0:
         if (rtc_enabled(s)) {
             s->offset_rtc = val - ls7a_rtc_ticks();
         }
         break;
     case SYS_RTCMATCH0:
         rtcmatch_write(s, val, 0);
         break;
     case SYS_RTCMATCH1:
         rtcmatch_write(s, val, 1);
         break;
     case SYS_RTCMATCH2:
         rtcmatch_write(s, val, 2);
         break;
     default:
         break;
     }
 }

 static const MemoryRegionOps ls7a_rtc_ops = {
     .read = ls7a_rtc_read,
     .write = ls7a_rtc_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
     .valid = {
         .min_access_size = 4,
         .max_access_size = 4,
     },
 };

 static void toy_timer_cb(void *opaque)
 {
     LS7ARtcState *s = opaque;

     if (toy_enabled(s)) {
         qemu_irq_raise(s->irq);
     }
 }

 static void rtc_timer_cb(void *opaque)
 {
     LS7ARtcState *s = opaque;

     if (rtc_enabled(s)) {
         qemu_irq_raise(s->irq);
     }
 }

 static void ls7a_rtc_realize(DeviceState *dev, Error **errp)
 {
     int i;
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
     LS7ARtcState *d = LS7A_RTC(sbd);
     memory_region_init_io(&d->iomem, NULL, &ls7a_rtc_ops,
                          (void *)d, "ls7a_rtc", 0x100);

     sysbus_init_irq(sbd, &d->irq);

     sysbus_init_mmio(sbd, &d->iomem);
     for (i = 0; i < TIMER_NUMS; i++) {
         d->toymatch[i] = 0;
         d->rtcmatch[i] = 0;
         d->toy_timer[i] = timer_new_ms(rtc_clock, toy_timer_cb, d);
         d->rtc_timer[i] = timer_new_ms(rtc_clock, rtc_timer_cb, d);
     }
     d->offset_toy = 0;
     d->offset_rtc = 0;

 }

 /* delete timer and clear reg when reset */
 static void ls7a_rtc_reset(DeviceState *dev)
 {
     int i;
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
     LS7ARtcState *d = LS7A_RTC(sbd);
     for (i = 0; i < TIMER_NUMS; i++) {
         if (toy_enabled(d)) {
             timer_del(d->toy_timer[i]);
         }
         if (rtc_enabled(d)) {
             timer_del(d->rtc_timer[i]);
         }
         d->toymatch[i] = 0;
         d->rtcmatch[i] = 0;
     }
     d->cntrctl = 0;
 }

 static int ls7a_rtc_pre_save(void *opaque)
 {
     LS7ARtcState *s = LS7A_RTC(opaque);

     ls7a_toy_stop(s);
     ls7a_rtc_stop(s);

     return 0;
 }

 static int ls7a_rtc_post_load(void *opaque, int version_id)
 {
     LS7ARtcState *s = LS7A_RTC(opaque);
     if (toy_enabled(s)) {
         ls7a_toy_start(s);
     }

     if (rtc_enabled(s)) {
         ls7a_rtc_start(s);
     }

     return 0;
 }

 static const VMStateDescription vmstate_ls7a_rtc = {
     .name = "ls7a_rtc",
     .version_id = 1,
     .minimum_version_id = 1,
     .pre_save = ls7a_rtc_pre_save,
     .post_load = ls7a_rtc_post_load,
     .fields = (VMStateField[]) {
         VMSTATE_INT64(offset_toy, LS7ARtcState),
         VMSTATE_INT64(offset_rtc, LS7ARtcState),
         VMSTATE_UINT32_ARRAY(toymatch, LS7ARtcState, TIMER_NUMS),
         VMSTATE_UINT32_ARRAY(rtcmatch, LS7ARtcState, TIMER_NUMS),
         VMSTATE_UINT32(cntrctl, LS7ARtcState),
         VMSTATE_END_OF_LIST()
     }
 };

 static void ls7a_rtc_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     dc->vmsd = &vmstate_ls7a_rtc;
     dc->realize = ls7a_rtc_realize;
     dc->reset = ls7a_rtc_reset;
     dc->desc = "ls7a rtc";
 }

 static const TypeInfo ls7a_rtc_info = {
     .name          = TYPE_LS7A_RTC,
     .parent        = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(LS7ARtcState),
     .class_init    = ls7a_rtc_class_init,
 };

 static void ls7a_rtc_register_types(void)
 {
     type_register_static(&ls7a_rtc_info);
 }

 type_init(ls7a_rtc_register_types)
	/* SPDX-License-Identifier: GPL-2.0-or-later */
	/*
	* Loongarch LS7A Real Time Clock emulation
	*
	* Copyright (C) 2021 Loongson Technology Corporation Limited
	*/

	#include "qemu/osdep.h"
	#include "hw/sysbus.h"
	#include "hw/irq.h"
	#include "include/hw/register.h"
	#include "qemu/timer.h"
	#include "sysemu/sysemu.h"
	#include "qemu/cutils.h"
	#include "qemu/log.h"
	#include "migration/vmstate.h"
	#include "hw/misc/unimp.h"
	#include "sysemu/rtc.h"
	#include "hw/registerfields.h"

	#define SYS_TOYTRIM 0x20
	#define SYS_TOYWRITE0 0x24
	#define SYS_TOYWRITE1 0x28
	#define SYS_TOYREAD0 0x2C
	#define SYS_TOYREAD1 0x30
	#define SYS_TOYMATCH0 0x34
	#define SYS_TOYMATCH1 0x38
	#define SYS_TOYMATCH2 0x3C
	#define SYS_RTCCTRL 0x40
	#define SYS_RTCTRIM 0x60
	#define SYS_RTCWRTIE0 0x64
	#define SYS_RTCREAD0 0x68
	#define SYS_RTCMATCH0 0x6C
	#define SYS_RTCMATCH1 0x70
	#define SYS_RTCMATCH2 0x74

	#define LS7A_RTC_FREQ 32768
	#define TIMER_NUMS 3
	/*
	* Shift bits and filed mask
	*/

	FIELD(TOY, MON, 26, 6)
	FIELD(TOY, DAY, 21, 5)
	FIELD(TOY, HOUR, 16, 5)
	FIELD(TOY, MIN, 10, 6)
	FIELD(TOY, SEC, 4, 6)
	FIELD(TOY, MSEC, 0, 4)

	FIELD(TOY_MATCH, YEAR, 26, 6)
	FIELD(TOY_MATCH, MON, 22, 4)
	FIELD(TOY_MATCH, DAY, 17, 5)
	FIELD(TOY_MATCH, HOUR, 12, 5)
	FIELD(TOY_MATCH, MIN, 6, 6)
	FIELD(TOY_MATCH, SEC, 0, 6)

	FIELD(RTC_CTRL, RTCEN, 13, 1)
	FIELD(RTC_CTRL, TOYEN, 11, 1)
	FIELD(RTC_CTRL, EO, 8, 1)

	#define TYPE_LS7A_RTC "ls7a_rtc"
	OBJECT_DECLARE_SIMPLE_TYPE(LS7ARtcState, LS7A_RTC)

	struct LS7ARtcState {
	SysBusDevice parent_obj;

	MemoryRegion iomem;
	/*
	* Needed to preserve the tick_count across migration, even if the
	* absolute value of the rtc_clock is different on the source and
	* destination.
	*/
	int64_t offset_toy;
	int64_t offset_rtc;
	int64_t data;
	int tidx;
	uint32_t toymatch[3];
	uint32_t toytrim;
	uint32_t cntrctl;
	uint32_t rtctrim;
	uint32_t rtccount;
	uint32_t rtcmatch[3];
	QEMUTimer *toy_timer[TIMER_NUMS];
	QEMUTimer *rtc_timer[TIMER_NUMS];
	qemu_irq irq;
	};

	/* switch nanoseconds time to rtc ticks */
	static uint64_t ls7a_rtc_ticks(void)
	{
	return qemu_clock_get_ns(rtc_clock) * LS7A_RTC_FREQ / NANOSECONDS_PER_SECOND;
	}

	/* switch rtc ticks to nanoseconds */
	static uint64_t ticks_to_ns(uint64_t ticks)
	{
	return ticks * NANOSECONDS_PER_SECOND / LS7A_RTC_FREQ;
	}

	static bool toy_enabled(LS7ARtcState *s)
	{
	return FIELD_EX32(s->cntrctl, RTC_CTRL, TOYEN) &&
	FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
	}

	static bool rtc_enabled(LS7ARtcState *s)
	{
	return FIELD_EX32(s->cntrctl, RTC_CTRL, RTCEN) &&
	FIELD_EX32(s->cntrctl, RTC_CTRL, EO);
	}

	/* parse struct tm to toy value */
	static uint64_t toy_time_to_val_mon(const struct tm *tm)
	{
	uint64_t val = 0;

	val = FIELD_DP32(val, TOY, MON, tm->tm_mon + 1);
	val = FIELD_DP32(val, TOY, DAY, tm->tm_mday);
	val = FIELD_DP32(val, TOY, HOUR, tm->tm_hour);
	val = FIELD_DP32(val, TOY, MIN, tm->tm_min);
	val = FIELD_DP32(val, TOY, SEC, tm->tm_sec);
	return val;
	}

	static void toymatch_val_to_time(LS7ARtcState s, uint64_t val, struct tm tm)
	{
	qemu_get_timedate(tm, s->offset_toy);
	tm->tm_sec = FIELD_EX32(val, TOY_MATCH, SEC);
	tm->tm_min = FIELD_EX32(val, TOY_MATCH, MIN);
	tm->tm_hour = FIELD_EX32(val, TOY_MATCH, HOUR);
	tm->tm_mday = FIELD_EX32(val, TOY_MATCH, DAY);
	tm->tm_mon = FIELD_EX32(val, TOY_MATCH, MON) - 1;
	tm->tm_year += (FIELD_EX32(val, TOY_MATCH, YEAR) - (tm->tm_year & 0x3f));
	}

	static void toymatch_write(LS7ARtcState *s, uint64_t val, int num)
	{
	int64_t now, expire_time;
	struct tm tm = {};

	/* it do not support write when toy disabled */
	if (toy_enabled(s)) {
	s->toymatch[num] = val;
	/* calculate expire time */
	now = qemu_clock_get_ms(rtc_clock);
	toymatch_val_to_time(s, val, &tm);
	expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
	timer_mod(s->toy_timer[num], expire_time);
	}
	}

	static void rtcmatch_write(LS7ARtcState *s, uint64_t val, int num)
	{
	uint64_t expire_ns;

	/* it do not support write when toy disabled */
	if (rtc_enabled(s)) {
	s->rtcmatch[num] = val;
	/* calculate expire time */
	expire_ns = ticks_to_ns(val) - ticks_to_ns(s->offset_rtc);
	timer_mod_ns(s->rtc_timer[num], expire_ns);
	}
	}

	static void ls7a_toy_stop(LS7ARtcState *s)
	{
	int i;

	/* delete timers, and when re-enabled, recalculate expire time */
	for (i = 0; i < TIMER_NUMS; i++) {
	timer_del(s->toy_timer[i]);
	}
	}

	static void ls7a_rtc_stop(LS7ARtcState *s)
	{
	int i;

	/* delete timers, and when re-enabled, recalculate expire time */
	for (i = 0; i < TIMER_NUMS; i++) {
	timer_del(s->rtc_timer[i]);
	}
	}

	static void ls7a_toy_start(LS7ARtcState *s)
	{
	int i;
	uint64_t expire_time, now;
	struct tm tm = {};

	now = qemu_clock_get_ms(rtc_clock);

	/* recalculate expire time and enable timer */
	for (i = 0; i < TIMER_NUMS; i++) {
	toymatch_val_to_time(s, s->toymatch[i], &tm);
	expire_time = now + (qemu_timedate_diff(&tm) - s->offset_toy) * 1000;
	timer_mod(s->toy_timer[i], expire_time);
	}
	}

	static void ls7a_rtc_start(LS7ARtcState *s)
	{
	int i;
	uint64_t expire_time;

	/* recalculate expire time and enable timer */
	for (i = 0; i < TIMER_NUMS; i++) {
	expire_time = ticks_to_ns(s->rtcmatch[i]) - ticks_to_ns(s->offset_rtc);
	timer_mod_ns(s->rtc_timer[i], expire_time);
	}
	}

	static uint64_t ls7a_rtc_read(void *opaque, hwaddr addr, unsigned size)
	{
	LS7ARtcState *s = LS7A_RTC(opaque);
	struct tm tm;
	int val = 0;

	switch (addr) {
	case SYS_TOYREAD0:
	if (toy_enabled(s)) {
	qemu_get_timedate(&tm, s->offset_toy);
	val = toy_time_to_val_mon(&tm);
	} else {
	/* return 0 when toy disabled */
	val = 0;
	}
	break;
	case SYS_TOYREAD1:
	if (toy_enabled(s)) {
	qemu_get_timedate(&tm, s->offset_toy);
	val = tm.tm_year;
	} else {
	/* return 0 when toy disabled */
	val = 0;
	}
	break;
	case SYS_TOYMATCH0:
	val = s->toymatch[0];
	break;
	case SYS_TOYMATCH1:
	val = s->toymatch[1];
	break;
	case SYS_TOYMATCH2:
	val = s->toymatch[2];
	break;
	case SYS_RTCCTRL:
	val = s->cntrctl;
	break;
	case SYS_RTCREAD0:
	if (rtc_enabled(s)) {
	val = ls7a_rtc_ticks() + s->offset_rtc;
	} else {
	/* return 0 when rtc disabled */
	val = 0;
	}
	break;
	case SYS_RTCMATCH0:
	val = s->rtcmatch[0];
	break;
	case SYS_RTCMATCH1:
	val = s->rtcmatch[1];
	break;
	case SYS_RTCMATCH2:
	val = s->rtcmatch[2];
	break;
	default:
	val = 0;
	break;
	}
	return val;
	}

	static void ls7a_rtc_write(void *opaque, hwaddr addr,
	uint64_t val, unsigned size)
	{
	int old_toyen, old_rtcen, new_toyen, new_rtcen;
	LS7ARtcState *s = LS7A_RTC(opaque);
	struct tm tm;

	switch (addr) {
	case SYS_TOYWRITE0:
	/* it do not support write when toy disabled */
	if (toy_enabled(s)) {
	qemu_get_timedate(&tm, s->offset_toy);
	tm.tm_sec = FIELD_EX32(val, TOY, SEC);
	tm.tm_min = FIELD_EX32(val, TOY, MIN);
	tm.tm_hour = FIELD_EX32(val, TOY, HOUR);
	tm.tm_mday = FIELD_EX32(val, TOY, DAY);
	tm.tm_mon = FIELD_EX32(val, TOY, MON) - 1;
	s->offset_toy = qemu_timedate_diff(&tm);
	}
	break;
	case SYS_TOYWRITE1:
	if (toy_enabled(s)) {
	qemu_get_timedate(&tm, s->offset_toy);
	tm.tm_year = val;
	s->offset_toy = qemu_timedate_diff(&tm);
	}
	break;
	case SYS_TOYMATCH0:
	toymatch_write(s, val, 0);
	break;
	case SYS_TOYMATCH1:
	toymatch_write(s, val, 1);
	break;
	case SYS_TOYMATCH2:
	toymatch_write(s, val, 2);
	break;
	case SYS_RTCCTRL:
	/* get old ctrl */
	old_toyen = toy_enabled(s);
	old_rtcen = rtc_enabled(s);

	s->cntrctl = val;
	/* get new ctrl */
	new_toyen = toy_enabled(s);
	new_rtcen = rtc_enabled(s);

	/*
	* we do not consider if EO changed, as it always set at most time.
	* toy or rtc enabled should start timer. otherwise, stop timer
	*/
	if (old_toyen != new_toyen) {
	if (new_toyen) {
	ls7a_toy_start(s);
	} else {
	ls7a_toy_stop(s);
	}
	}
	if (old_rtcen != new_rtcen) {
	if (new_rtcen) {
	ls7a_rtc_start(s);
	} else {
	ls7a_rtc_stop(s);
	}
	}
	break;
	case SYS_RTCWRTIE0:
	if (rtc_enabled(s)) {
	s->offset_rtc = val - ls7a_rtc_ticks();
	}
	break;
	case SYS_RTCMATCH0:
	rtcmatch_write(s, val, 0);
	break;
	case SYS_RTCMATCH1:
	rtcmatch_write(s, val, 1);
	break;
	case SYS_RTCMATCH2:
	rtcmatch_write(s, val, 2);
	break;
	default:
	break;
	}
	}

	static const MemoryRegionOps ls7a_rtc_ops = {
	.read = ls7a_rtc_read,
	.write = ls7a_rtc_write,
	.endianness = DEVICE_LITTLE_ENDIAN,
	.valid = {
	.min_access_size = 4,
	.max_access_size = 4,
	},
	};

	static void toy_timer_cb(void *opaque)
	{
	LS7ARtcState *s = opaque;

	if (toy_enabled(s)) {
	qemu_irq_raise(s->irq);
	}
	}

	static void rtc_timer_cb(void *opaque)
	{
	LS7ARtcState *s = opaque;

	if (rtc_enabled(s)) {
	qemu_irq_raise(s->irq);
	}
	}

	static void ls7a_rtc_realize(DeviceState dev, Error *errp)
	{
	int i;
	SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
	LS7ARtcState *d = LS7A_RTC(sbd);
	memory_region_init_io(&d->iomem, NULL, &ls7a_rtc_ops,
	(void *)d, "ls7a_rtc", 0x100);

	sysbus_init_irq(sbd, &d->irq);

	sysbus_init_mmio(sbd, &d->iomem);
	for (i = 0; i < TIMER_NUMS; i++) {
	d->toymatch[i] = 0;
	d->rtcmatch[i] = 0;
	d->toy_timer[i] = timer_new_ms(rtc_clock, toy_timer_cb, d);
	d->rtc_timer[i] = timer_new_ms(rtc_clock, rtc_timer_cb, d);
	}
	d->offset_toy = 0;
	d->offset_rtc = 0;

	}

	/* delete timer and clear reg when reset */
	static void ls7a_rtc_reset(DeviceState *dev)
	{
	int i;
	SysBusDevice *sbd = SYS_BUS_DEVICE(dev);
	LS7ARtcState *d = LS7A_RTC(sbd);
	for (i = 0; i < TIMER_NUMS; i++) {
	if (toy_enabled(d)) {
	timer_del(d->toy_timer[i]);
	}
	if (rtc_enabled(d)) {
	timer_del(d->rtc_timer[i]);
	}
	d->toymatch[i] = 0;
	d->rtcmatch[i] = 0;
	}
	d->cntrctl = 0;
	}

	static int ls7a_rtc_pre_save(void *opaque)
	{
	LS7ARtcState *s = LS7A_RTC(opaque);

	ls7a_toy_stop(s);
	ls7a_rtc_stop(s);

	return 0;
	}

	static int ls7a_rtc_post_load(void *opaque, int version_id)
	{
	LS7ARtcState *s = LS7A_RTC(opaque);
	if (toy_enabled(s)) {
	ls7a_toy_start(s);
	}

	if (rtc_enabled(s)) {
	ls7a_rtc_start(s);
	}

	return 0;
	}

	static const VMStateDescription vmstate_ls7a_rtc = {
	.name = "ls7a_rtc",
	.version_id = 1,
	.minimum_version_id = 1,
	.pre_save = ls7a_rtc_pre_save,
	.post_load = ls7a_rtc_post_load,
	.fields = (VMStateField[]) {
	VMSTATE_INT64(offset_toy, LS7ARtcState),
	VMSTATE_INT64(offset_rtc, LS7ARtcState),
	VMSTATE_UINT32_ARRAY(toymatch, LS7ARtcState, TIMER_NUMS),
	VMSTATE_UINT32_ARRAY(rtcmatch, LS7ARtcState, TIMER_NUMS),
	VMSTATE_UINT32(cntrctl, LS7ARtcState),
	VMSTATE_END_OF_LIST()
	}
	};

	static void ls7a_rtc_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	dc->vmsd = &vmstate_ls7a_rtc;
	dc->realize = ls7a_rtc_realize;
	dc->reset = ls7a_rtc_reset;
	dc->desc = "ls7a rtc";
	}

	static const TypeInfo ls7a_rtc_info = {
	.name = TYPE_LS7A_RTC,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(LS7ARtcState),
	.class_init = ls7a_rtc_class_init,
	};

	static void ls7a_rtc_register_types(void)
	{
	type_register_static(&ls7a_rtc_info);
	}

	type_init(ls7a_rtc_register_types)