hw/rtc/m48t59.c - qemu - Git at Google

 /*
  * QEMU M48T59 and M48T08 NVRAM emulation for PPC PREP and Sparc platforms
  *
  * Copyright (c) 2003-2005, 2007, 2017 Jocelyn Mayer
  * Copyright (c) 2013 Hervé Poussineau
  *
  * Permission is hereby granted, free of charge, to any person obtaining a copy
  * of this software and associated documentation files (the "Software"), to deal
  * in the Software without restriction, including without limitation the rights
  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  * copies of the Software, and to permit persons to whom the Software is
  * furnished to do so, subject to the following conditions:
  *
  * The above copyright notice and this permission notice shall be included in
  * all copies or substantial portions of the Software.
  *
  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  * THE SOFTWARE.
  */

 #include "qemu/osdep.h"
 #include "hw/irq.h"
 #include "hw/qdev-properties.h"
 #include "hw/rtc/m48t59.h"
 #include "qemu/timer.h"
 #include "sysemu/runstate.h"
 #include "sysemu/rtc.h"
 #include "sysemu/sysemu.h"
 #include "hw/sysbus.h"
 #include "qapi/error.h"
 #include "qemu/bcd.h"
 #include "qemu/module.h"
 #include "trace.h"
 #include "sysemu/watchdog.h"

 #include "m48t59-internal.h"
 #include "migration/vmstate.h"
 #include "qom/object.h"

 #define TYPE_M48TXX_SYS_BUS "sysbus-m48txx"
 typedef struct M48txxSysBusDeviceClass M48txxSysBusDeviceClass;
 typedef struct M48txxSysBusState M48txxSysBusState;
 DECLARE_OBJ_CHECKERS(M48txxSysBusState, M48txxSysBusDeviceClass,
                      M48TXX_SYS_BUS, TYPE_M48TXX_SYS_BUS)

 /*
  * Chipset docs:
  * http://www.st.com/stonline/products/literature/ds/2410/m48t02.pdf
  * http://www.st.com/stonline/products/literature/ds/2411/m48t08.pdf
  * http://www.st.com/stonline/products/literature/od/7001/m48t59y.pdf
  */

 struct M48txxSysBusState {
     SysBusDevice parent_obj;
     M48t59State state;
     MemoryRegion io;
 };

 struct M48txxSysBusDeviceClass {
     SysBusDeviceClass parent_class;
     M48txxInfo info;
 };

 static M48txxInfo m48txx_sysbus_info[] = {
     {
         .bus_name = "sysbus-m48t02",
         .model = 2,
         .size = 0x800,
     },{
         .bus_name = "sysbus-m48t08",
         .model = 8,
         .size = 0x2000,
     },{
         .bus_name = "sysbus-m48t59",
         .model = 59,
         .size = 0x2000,
     }
 };


 /* Fake timer functions */

 /* Alarm management */
 static void alarm_cb (void *opaque)
 {
     struct tm tm;
     uint64_t next_time;
     M48t59State *NVRAM = opaque;

     qemu_set_irq(NVRAM->IRQ, 1);
     if ((NVRAM->buffer[0x1FF5] & 0x80) == 0 &&
         (NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
         (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
         (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
         /* Repeat once a month */
         qemu_get_timedate(&tm, NVRAM->time_offset);
         tm.tm_mon++;
         if (tm.tm_mon == 13) {
             tm.tm_mon = 1;
             tm.tm_year++;
         }
         next_time = qemu_timedate_diff(&tm) - NVRAM->time_offset;
     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
                (NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
                (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
         /* Repeat once a day */
         next_time = 24 * 60 * 60;
     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
                (NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
                (NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
         /* Repeat once an hour */
         next_time = 60 * 60;
     } else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
                (NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
                (NVRAM->buffer[0x1FF3] & 0x80) != 0 &&
                (NVRAM->buffer[0x1FF2] & 0x80) == 0) {
         /* Repeat once a minute */
         next_time = 60;
     } else {
         /* Repeat once a second */
         next_time = 1;
     }
     timer_mod(NVRAM->alrm_timer, qemu_clock_get_ns(rtc_clock) +
                     next_time * 1000);
     qemu_set_irq(NVRAM->IRQ, 0);
 }

 static void set_alarm(M48t59State *NVRAM)
 {
     int64_t diff;
     if (NVRAM->alrm_timer != NULL) {
         timer_del(NVRAM->alrm_timer);
         diff = qemu_timedate_diff(&NVRAM->alarm) - NVRAM->time_offset;
         if (diff > 0)
             timer_mod(NVRAM->alrm_timer, diff * 1000);
     }
 }

 /* RTC management helpers */
 static inline void get_time(M48t59State *NVRAM, struct tm *tm)
 {
     qemu_get_timedate(tm, NVRAM->time_offset);
 }

 static void set_time(M48t59State *NVRAM, struct tm *tm)
 {
     NVRAM->time_offset = qemu_timedate_diff(tm);
     set_alarm(NVRAM);
 }

 /* Watchdog management */
 static void watchdog_cb (void *opaque)
 {
     M48t59State *NVRAM = opaque;

     NVRAM->buffer[0x1FF0] |= 0x80;
     if (NVRAM->buffer[0x1FF7] & 0x80) {
         NVRAM->buffer[0x1FF7] = 0x00;
         NVRAM->buffer[0x1FFC] &= ~0x40;
         watchdog_perform_action();
     } else {
         qemu_set_irq(NVRAM->IRQ, 1);
         qemu_set_irq(NVRAM->IRQ, 0);
     }
 }

 static void set_up_watchdog(M48t59State *NVRAM, uint8_t value)
 {
     uint64_t interval; /* in 1/16 seconds */

     NVRAM->buffer[0x1FF0] &= ~0x80;
     if (NVRAM->wd_timer != NULL) {
         timer_del(NVRAM->wd_timer);
         if (value != 0) {
             interval = (1 << (2 * (value & 0x03))) * ((value >> 2) & 0x1F);
             timer_mod(NVRAM->wd_timer, ((uint64_t)time(NULL) * 1000) +
                            ((interval * 1000) >> 4));
         }
     }
 }

 /* Direct access to NVRAM */
 void m48t59_write(M48t59State *NVRAM, uint32_t addr, uint32_t val)
 {
     struct tm tm;
     int tmp;

     trace_m48txx_nvram_mem_write(addr, val);

     /* check for NVRAM access */
     if ((NVRAM->model == 2 && addr < 0x7f8) ||
         (NVRAM->model == 8 && addr < 0x1ff8) ||
         (NVRAM->model == 59 && addr < 0x1ff0)) {
         goto do_write;
     }

     /* TOD access */
     switch (addr) {
     case 0x1FF0:
         /* flags register : read-only */
         break;
     case 0x1FF1:
         /* unused */
         break;
     case 0x1FF2:
         /* alarm seconds */
         tmp = from_bcd(val & 0x7F);
         if (tmp >= 0 && tmp <= 59) {
             NVRAM->alarm.tm_sec = tmp;
             NVRAM->buffer[0x1FF2] = val;
             set_alarm(NVRAM);
         }
         break;
     case 0x1FF3:
         /* alarm minutes */
         tmp = from_bcd(val & 0x7F);
         if (tmp >= 0 && tmp <= 59) {
             NVRAM->alarm.tm_min = tmp;
             NVRAM->buffer[0x1FF3] = val;
             set_alarm(NVRAM);
         }
         break;
     case 0x1FF4:
         /* alarm hours */
         tmp = from_bcd(val & 0x3F);
         if (tmp >= 0 && tmp <= 23) {
             NVRAM->alarm.tm_hour = tmp;
             NVRAM->buffer[0x1FF4] = val;
             set_alarm(NVRAM);
         }
         break;
     case 0x1FF5:
         /* alarm date */
         tmp = from_bcd(val & 0x3F);
         if (tmp != 0) {
             NVRAM->alarm.tm_mday = tmp;
             NVRAM->buffer[0x1FF5] = val;
             set_alarm(NVRAM);
         }
         break;
     case 0x1FF6:
         /* interrupts */
         NVRAM->buffer[0x1FF6] = val;
         break;
     case 0x1FF7:
         /* watchdog */
         NVRAM->buffer[0x1FF7] = val;
         set_up_watchdog(NVRAM, val);
         break;
     case 0x1FF8:
     case 0x07F8:
         /* control */
        NVRAM->buffer[addr] = (val & ~0xA0) | 0x90;
         break;
     case 0x1FF9:
     case 0x07F9:
         /* seconds (BCD) */
         tmp = from_bcd(val & 0x7F);
         if (tmp >= 0 && tmp <= 59) {
             get_time(NVRAM, &tm);
             tm.tm_sec = tmp;
             set_time(NVRAM, &tm);
         }
         if ((val & 0x80) ^ (NVRAM->buffer[addr] & 0x80)) {
             if (val & 0x80) {
                 NVRAM->stop_time = time(NULL);
             } else {
                 NVRAM->time_offset += NVRAM->stop_time - time(NULL);
                 NVRAM->stop_time = 0;
             }
         }
         NVRAM->buffer[addr] = val & 0x80;
         break;
     case 0x1FFA:
     case 0x07FA:
         /* minutes (BCD) */
         tmp = from_bcd(val & 0x7F);
         if (tmp >= 0 && tmp <= 59) {
             get_time(NVRAM, &tm);
             tm.tm_min = tmp;
             set_time(NVRAM, &tm);
         }
         break;
     case 0x1FFB:
     case 0x07FB:
         /* hours (BCD) */
         tmp = from_bcd(val & 0x3F);
         if (tmp >= 0 && tmp <= 23) {
             get_time(NVRAM, &tm);
             tm.tm_hour = tmp;
             set_time(NVRAM, &tm);
         }
         break;
     case 0x1FFC:
     case 0x07FC:
         /* day of the week / century */
         tmp = from_bcd(val & 0x07);
         get_time(NVRAM, &tm);
         tm.tm_wday = tmp;
         set_time(NVRAM, &tm);
         NVRAM->buffer[addr] = val & 0x40;
         break;
     case 0x1FFD:
     case 0x07FD:
         /* date (BCD) */
         tmp = from_bcd(val & 0x3F);
         if (tmp != 0) {
             get_time(NVRAM, &tm);
             tm.tm_mday = tmp;
             set_time(NVRAM, &tm);
         }
         break;
     case 0x1FFE:
     case 0x07FE:
         /* month */
         tmp = from_bcd(val & 0x1F);
         if (tmp >= 1 && tmp <= 12) {
             get_time(NVRAM, &tm);
             tm.tm_mon = tmp - 1;
             set_time(NVRAM, &tm);
         }
         break;
     case 0x1FFF:
     case 0x07FF:
         /* year */
         tmp = from_bcd(val);
         if (tmp >= 0 && tmp <= 99) {
             get_time(NVRAM, &tm);
             tm.tm_year = from_bcd(val) + NVRAM->base_year - 1900;
             set_time(NVRAM, &tm);
         }
         break;
     default:
         /* Check lock registers state */
         if (addr >= 0x20 && addr <= 0x2F && (NVRAM->lock & 1))
             break;
         if (addr >= 0x30 && addr <= 0x3F && (NVRAM->lock & 2))
             break;
     do_write:
         if (addr < NVRAM->size) {
             NVRAM->buffer[addr] = val & 0xFF;
         }
         break;
     }
 }

 uint32_t m48t59_read(M48t59State *NVRAM, uint32_t addr)
 {
     struct tm tm;
     uint32_t retval = 0xFF;

     /* check for NVRAM access */
     if ((NVRAM->model == 2 && addr < 0x078f) ||
         (NVRAM->model == 8 && addr < 0x1ff8) ||
         (NVRAM->model == 59 && addr < 0x1ff0)) {
         goto do_read;
     }

     /* TOD access */
     switch (addr) {
     case 0x1FF0:
         /* flags register */
         goto do_read;
     case 0x1FF1:
         /* unused */
         retval = 0;
         break;
     case 0x1FF2:
         /* alarm seconds */
         goto do_read;
     case 0x1FF3:
         /* alarm minutes */
         goto do_read;
     case 0x1FF4:
         /* alarm hours */
         goto do_read;
     case 0x1FF5:
         /* alarm date */
         goto do_read;
     case 0x1FF6:
         /* interrupts */
         goto do_read;
     case 0x1FF7:
         /* A read resets the watchdog */
         set_up_watchdog(NVRAM, NVRAM->buffer[0x1FF7]);
         goto do_read;
     case 0x1FF8:
     case 0x07F8:
         /* control */
         goto do_read;
     case 0x1FF9:
     case 0x07F9:
         /* seconds (BCD) */
         get_time(NVRAM, &tm);
         retval = (NVRAM->buffer[addr] & 0x80) | to_bcd(tm.tm_sec);
         break;
     case 0x1FFA:
     case 0x07FA:
         /* minutes (BCD) */
         get_time(NVRAM, &tm);
         retval = to_bcd(tm.tm_min);
         break;
     case 0x1FFB:
     case 0x07FB:
         /* hours (BCD) */
         get_time(NVRAM, &tm);
         retval = to_bcd(tm.tm_hour);
         break;
     case 0x1FFC:
     case 0x07FC:
         /* day of the week / century */
         get_time(NVRAM, &tm);
         retval = NVRAM->buffer[addr] | tm.tm_wday;
         break;
     case 0x1FFD:
     case 0x07FD:
         /* date */
         get_time(NVRAM, &tm);
         retval = to_bcd(tm.tm_mday);
         break;
     case 0x1FFE:
     case 0x07FE:
         /* month */
         get_time(NVRAM, &tm);
         retval = to_bcd(tm.tm_mon + 1);
         break;
     case 0x1FFF:
     case 0x07FF:
         /* year */
         get_time(NVRAM, &tm);
         retval = to_bcd((tm.tm_year + 1900 - NVRAM->base_year) % 100);
         break;
     default:
         /* Check lock registers state */
         if (addr >= 0x20 && addr <= 0x2F && (NVRAM->lock & 1))
             break;
         if (addr >= 0x30 && addr <= 0x3F && (NVRAM->lock & 2))
             break;
     do_read:
         if (addr < NVRAM->size) {
             retval = NVRAM->buffer[addr];
         }
         break;
     }
     trace_m48txx_nvram_mem_read(addr, retval);

     return retval;
 }

 /* IO access to NVRAM */
 static void NVRAM_writeb(void *opaque, hwaddr addr, uint64_t val,
                          unsigned size)
 {
     M48t59State *NVRAM = opaque;

     trace_m48txx_nvram_io_write(addr, val);
     switch (addr) {
     case 0:
         NVRAM->addr &= ~0x00FF;
         NVRAM->addr |= val;
         break;
     case 1:
         NVRAM->addr &= ~0xFF00;
         NVRAM->addr |= val << 8;
         break;
     case 3:
         m48t59_write(NVRAM, NVRAM->addr, val);
         NVRAM->addr = 0x0000;
         break;
     default:
         break;
     }
 }

 static uint64_t NVRAM_readb(void *opaque, hwaddr addr, unsigned size)
 {
     M48t59State *NVRAM = opaque;
     uint32_t retval;

     switch (addr) {
     case 3:
         retval = m48t59_read(NVRAM, NVRAM->addr);
         break;
     default:
         retval = -1;
         break;
     }
     trace_m48txx_nvram_io_read(addr, retval);

     return retval;
 }

 static uint64_t nvram_read(void *opaque, hwaddr addr, unsigned size)
 {
     M48t59State *NVRAM = opaque;

     return m48t59_read(NVRAM, addr);
 }

 static void nvram_write(void *opaque, hwaddr addr, uint64_t value,
                         unsigned size)
 {
     M48t59State *NVRAM = opaque;

     return m48t59_write(NVRAM, addr, value);
 }

 static const MemoryRegionOps nvram_ops = {
     .read = nvram_read,
     .write = nvram_write,
     .impl.min_access_size = 1,
     .impl.max_access_size = 1,
     .valid.min_access_size = 1,
     .valid.max_access_size = 4,
     .endianness = DEVICE_BIG_ENDIAN,
 };

 static const VMStateDescription vmstate_m48t59 = {
     .name = "m48t59",
     .version_id = 1,
     .minimum_version_id = 1,
     .fields = (const VMStateField[]) {
         VMSTATE_UINT8(lock, M48t59State),
         VMSTATE_UINT16(addr, M48t59State),
         VMSTATE_VBUFFER_UINT32(buffer, M48t59State, 0, NULL, size),
         VMSTATE_END_OF_LIST()
     }
 };

 void m48t59_reset_common(M48t59State *NVRAM)
 {
     NVRAM->addr = 0;
     NVRAM->lock = 0;
     if (NVRAM->alrm_timer != NULL)
         timer_del(NVRAM->alrm_timer);

     if (NVRAM->wd_timer != NULL)
         timer_del(NVRAM->wd_timer);
 }

 static void m48t59_reset_sysbus(DeviceState *d)
 {
     M48txxSysBusState *sys = M48TXX_SYS_BUS(d);
     M48t59State *NVRAM = &sys->state;

     m48t59_reset_common(NVRAM);
 }

 const MemoryRegionOps m48t59_io_ops = {
     .read = NVRAM_readb,
     .write = NVRAM_writeb,
     .impl = {
         .min_access_size = 1,
         .max_access_size = 1,
     },
     .endianness = DEVICE_LITTLE_ENDIAN,
 };

 void m48t59_realize_common(M48t59State *s, Error **errp)
 {
     s->buffer = g_malloc0(s->size);
     if (s->model == 59) {
         s->alrm_timer = timer_new_ns(rtc_clock, &alarm_cb, s);
         s->wd_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &watchdog_cb, s);
     }
     qemu_get_timedate(&s->alarm, 0);
 }

 static void m48t59_init1(Object *obj)
 {
     M48txxSysBusDeviceClass *u = M48TXX_SYS_BUS_GET_CLASS(obj);
     M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
     SysBusDevice *dev = SYS_BUS_DEVICE(obj);
     M48t59State *s = &d->state;

     s->model = u->info.model;
     s->size = u->info.size;
     sysbus_init_irq(dev, &s->IRQ);

     memory_region_init_io(&s->iomem, obj, &nvram_ops, s, "m48t59.nvram",
                           s->size);
     memory_region_init_io(&d->io, obj, &m48t59_io_ops, s, "m48t59", 4);
 }

 static void m48t59_realize(DeviceState *dev, Error **errp)
 {
     M48txxSysBusState *d = M48TXX_SYS_BUS(dev);
     M48t59State *s = &d->state;
     SysBusDevice *sbd = SYS_BUS_DEVICE(dev);

     sysbus_init_mmio(sbd, &s->iomem);
     sysbus_init_mmio(sbd, &d->io);
     m48t59_realize_common(s, errp);
 }

 static uint32_t m48txx_sysbus_read(Nvram *obj, uint32_t addr)
 {
     M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
     return m48t59_read(&d->state, addr);
 }

 static void m48txx_sysbus_write(Nvram *obj, uint32_t addr, uint32_t val)
 {
     M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
     m48t59_write(&d->state, addr, val);
 }

 static void m48txx_sysbus_toggle_lock(Nvram *obj, int lock)
 {
     M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
     m48t59_toggle_lock(&d->state, lock);
 }

 static Property m48t59_sysbus_properties[] = {
     DEFINE_PROP_INT32("base-year", M48txxSysBusState, state.base_year, 0),
     DEFINE_PROP_END_OF_LIST(),
 };

 static void m48txx_sysbus_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);
     NvramClass *nc = NVRAM_CLASS(klass);

     dc->realize = m48t59_realize;
     device_class_set_legacy_reset(dc, m48t59_reset_sysbus);
     device_class_set_props(dc, m48t59_sysbus_properties);
     dc->vmsd = &vmstate_m48t59;
     nc->read = m48txx_sysbus_read;
     nc->write = m48txx_sysbus_write;
     nc->toggle_lock = m48txx_sysbus_toggle_lock;
 }

 static void m48txx_sysbus_concrete_class_init(ObjectClass *klass, void *data)
 {
     M48txxSysBusDeviceClass *u = M48TXX_SYS_BUS_CLASS(klass);
     M48txxInfo *info = data;

     u->info = *info;
 }

 static const TypeInfo nvram_info = {
     .name = TYPE_NVRAM,
     .parent = TYPE_INTERFACE,
     .class_size = sizeof(NvramClass),
 };

 static const TypeInfo m48txx_sysbus_type_info = {
     .name = TYPE_M48TXX_SYS_BUS,
     .parent = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(M48txxSysBusState),
     .instance_init = m48t59_init1,
     .abstract = true,
     .class_init = m48txx_sysbus_class_init,
     .interfaces = (InterfaceInfo[]) {
         { TYPE_NVRAM },
         { }
     }
 };

 static void m48t59_register_types(void)
 {
     TypeInfo sysbus_type_info = {
         .parent = TYPE_M48TXX_SYS_BUS,
         .class_size = sizeof(M48txxSysBusDeviceClass),
         .class_init = m48txx_sysbus_concrete_class_init,
     };
     int i;

     type_register_static(&nvram_info);
     type_register_static(&m48txx_sysbus_type_info);

     for (i = 0; i < ARRAY_SIZE(m48txx_sysbus_info); i++) {
         sysbus_type_info.name = m48txx_sysbus_info[i].bus_name;
         sysbus_type_info.class_data = &m48txx_sysbus_info[i];
         type_register(&sysbus_type_info);
     }
 }

 type_init(m48t59_register_types)
	/*
	* QEMU M48T59 and M48T08 NVRAM emulation for PPC PREP and Sparc platforms
	*
	* Copyright (c) 2003-2005, 2007, 2017 Jocelyn Mayer
	* Copyright (c) 2013 Hervé Poussineau
	*
	* Permission is hereby granted, free of charge, to any person obtaining a copy
	* of this software and associated documentation files (the "Software"), to deal
	* in the Software without restriction, including without limitation the rights
	* to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	* copies of the Software, and to permit persons to whom the Software is
	* furnished to do so, subject to the following conditions:
	*
	* The above copyright notice and this permission notice shall be included in
	* all copies or substantial portions of the Software.
	*
	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	* THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	* OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
	* THE SOFTWARE.
	*/

	#include "qemu/osdep.h"
	#include "hw/irq.h"
	#include "hw/qdev-properties.h"
	#include "hw/rtc/m48t59.h"
	#include "qemu/timer.h"
	#include "sysemu/runstate.h"
	#include "sysemu/rtc.h"
	#include "sysemu/sysemu.h"
	#include "hw/sysbus.h"
	#include "qapi/error.h"
	#include "qemu/bcd.h"
	#include "qemu/module.h"
	#include "trace.h"
	#include "sysemu/watchdog.h"

	#include "m48t59-internal.h"
	#include "migration/vmstate.h"
	#include "qom/object.h"

	#define TYPE_M48TXX_SYS_BUS "sysbus-m48txx"
	typedef struct M48txxSysBusDeviceClass M48txxSysBusDeviceClass;
	typedef struct M48txxSysBusState M48txxSysBusState;
	DECLARE_OBJ_CHECKERS(M48txxSysBusState, M48txxSysBusDeviceClass,
	M48TXX_SYS_BUS, TYPE_M48TXX_SYS_BUS)

	/*
	* Chipset docs:
	* http://www.st.com/stonline/products/literature/ds/2410/m48t02.pdf
	* http://www.st.com/stonline/products/literature/ds/2411/m48t08.pdf
	* http://www.st.com/stonline/products/literature/od/7001/m48t59y.pdf
	*/

	struct M48txxSysBusState {
	SysBusDevice parent_obj;
	M48t59State state;
	MemoryRegion io;
	};

	struct M48txxSysBusDeviceClass {
	SysBusDeviceClass parent_class;
	M48txxInfo info;
	};

	static M48txxInfo m48txx_sysbus_info[] = {
	{
	.bus_name = "sysbus-m48t02",
	.model = 2,
	.size = 0x800,
	},{
	.bus_name = "sysbus-m48t08",
	.model = 8,
	.size = 0x2000,
	},{
	.bus_name = "sysbus-m48t59",
	.model = 59,
	.size = 0x2000,
	}
	};


	/* Fake timer functions */

	/* Alarm management */
	static void alarm_cb (void *opaque)
	{
	struct tm tm;
	uint64_t next_time;
	M48t59State *NVRAM = opaque;

	qemu_set_irq(NVRAM->IRQ, 1);
	if ((NVRAM->buffer[0x1FF5] & 0x80) == 0 &&
	(NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
	(NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
	(NVRAM->buffer[0x1FF2] & 0x80) == 0) {
	/* Repeat once a month */
	qemu_get_timedate(&tm, NVRAM->time_offset);
	tm.tm_mon++;
	if (tm.tm_mon == 13) {
	tm.tm_mon = 1;
	tm.tm_year++;
	}
	next_time = qemu_timedate_diff(&tm) - NVRAM->time_offset;
	} else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
	(NVRAM->buffer[0x1FF4] & 0x80) == 0 &&
	(NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
	(NVRAM->buffer[0x1FF2] & 0x80) == 0) {
	/* Repeat once a day */
	next_time = 24 * 60 * 60;
	} else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
	(NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
	(NVRAM->buffer[0x1FF3] & 0x80) == 0 &&
	(NVRAM->buffer[0x1FF2] & 0x80) == 0) {
	/* Repeat once an hour */
	next_time = 60 * 60;
	} else if ((NVRAM->buffer[0x1FF5] & 0x80) != 0 &&
	(NVRAM->buffer[0x1FF4] & 0x80) != 0 &&
	(NVRAM->buffer[0x1FF3] & 0x80) != 0 &&
	(NVRAM->buffer[0x1FF2] & 0x80) == 0) {
	/* Repeat once a minute */
	next_time = 60;
	} else {
	/* Repeat once a second */
	next_time = 1;
	}
	timer_mod(NVRAM->alrm_timer, qemu_clock_get_ns(rtc_clock) +
	next_time * 1000);
	qemu_set_irq(NVRAM->IRQ, 0);
	}

	static void set_alarm(M48t59State *NVRAM)
	{
	int64_t diff;
	if (NVRAM->alrm_timer != NULL) {
	timer_del(NVRAM->alrm_timer);
	diff = qemu_timedate_diff(&NVRAM->alarm) - NVRAM->time_offset;
	if (diff > 0)
	timer_mod(NVRAM->alrm_timer, diff * 1000);
	}
	}

	/* RTC management helpers */
	static inline void get_time(M48t59State NVRAM, struct tm tm)
	{
	qemu_get_timedate(tm, NVRAM->time_offset);
	}

	static void set_time(M48t59State NVRAM, struct tm tm)
	{
	NVRAM->time_offset = qemu_timedate_diff(tm);
	set_alarm(NVRAM);
	}

	/* Watchdog management */
	static void watchdog_cb (void *opaque)
	{
	M48t59State *NVRAM = opaque;

	NVRAM->buffer[0x1FF0] \|= 0x80;
	if (NVRAM->buffer[0x1FF7] & 0x80) {
	NVRAM->buffer[0x1FF7] = 0x00;
	NVRAM->buffer[0x1FFC] &= ~0x40;
	watchdog_perform_action();
	} else {
	qemu_set_irq(NVRAM->IRQ, 1);
	qemu_set_irq(NVRAM->IRQ, 0);
	}
	}

	static void set_up_watchdog(M48t59State *NVRAM, uint8_t value)
	{
	uint64_t interval; /* in 1/16 seconds */

	NVRAM->buffer[0x1FF0] &= ~0x80;
	if (NVRAM->wd_timer != NULL) {
	timer_del(NVRAM->wd_timer);
	if (value != 0) {
	interval = (1 << (2 * (value & 0x03))) * ((value >> 2) & 0x1F);
	timer_mod(NVRAM->wd_timer, ((uint64_t)time(NULL) * 1000) +
	((interval * 1000) >> 4));
	}
	}
	}

	/* Direct access to NVRAM */
	void m48t59_write(M48t59State *NVRAM, uint32_t addr, uint32_t val)
	{
	struct tm tm;
	int tmp;

	trace_m48txx_nvram_mem_write(addr, val);

	/* check for NVRAM access */
	if ((NVRAM->model == 2 && addr < 0x7f8) \|\|
	(NVRAM->model == 8 && addr < 0x1ff8) \|\|
	(NVRAM->model == 59 && addr < 0x1ff0)) {
	goto do_write;
	}

	/* TOD access */
	switch (addr) {
	case 0x1FF0:
	/* flags register : read-only */
	break;
	case 0x1FF1:
	/* unused */
	break;
	case 0x1FF2:
	/* alarm seconds */
	tmp = from_bcd(val & 0x7F);
	if (tmp >= 0 && tmp <= 59) {
	NVRAM->alarm.tm_sec = tmp;
	NVRAM->buffer[0x1FF2] = val;
	set_alarm(NVRAM);
	}
	break;
	case 0x1FF3:
	/* alarm minutes */
	tmp = from_bcd(val & 0x7F);
	if (tmp >= 0 && tmp <= 59) {
	NVRAM->alarm.tm_min = tmp;
	NVRAM->buffer[0x1FF3] = val;
	set_alarm(NVRAM);
	}
	break;
	case 0x1FF4:
	/* alarm hours */
	tmp = from_bcd(val & 0x3F);
	if (tmp >= 0 && tmp <= 23) {
	NVRAM->alarm.tm_hour = tmp;
	NVRAM->buffer[0x1FF4] = val;
	set_alarm(NVRAM);
	}
	break;
	case 0x1FF5:
	/* alarm date */
	tmp = from_bcd(val & 0x3F);
	if (tmp != 0) {
	NVRAM->alarm.tm_mday = tmp;
	NVRAM->buffer[0x1FF5] = val;
	set_alarm(NVRAM);
	}
	break;
	case 0x1FF6:
	/* interrupts */
	NVRAM->buffer[0x1FF6] = val;
	break;
	case 0x1FF7:
	/* watchdog */
	NVRAM->buffer[0x1FF7] = val;
	set_up_watchdog(NVRAM, val);
	break;
	case 0x1FF8:
	case 0x07F8:
	/* control */
	NVRAM->buffer[addr] = (val & ~0xA0) \| 0x90;
	break;
	case 0x1FF9:
	case 0x07F9:
	/* seconds (BCD) */
	tmp = from_bcd(val & 0x7F);
	if (tmp >= 0 && tmp <= 59) {
	get_time(NVRAM, &tm);
	tm.tm_sec = tmp;
	set_time(NVRAM, &tm);
	}
	if ((val & 0x80) ^ (NVRAM->buffer[addr] & 0x80)) {
	if (val & 0x80) {
	NVRAM->stop_time = time(NULL);
	} else {
	NVRAM->time_offset += NVRAM->stop_time - time(NULL);
	NVRAM->stop_time = 0;
	}
	}
	NVRAM->buffer[addr] = val & 0x80;
	break;
	case 0x1FFA:
	case 0x07FA:
	/* minutes (BCD) */
	tmp = from_bcd(val & 0x7F);
	if (tmp >= 0 && tmp <= 59) {
	get_time(NVRAM, &tm);
	tm.tm_min = tmp;
	set_time(NVRAM, &tm);
	}
	break;
	case 0x1FFB:
	case 0x07FB:
	/* hours (BCD) */
	tmp = from_bcd(val & 0x3F);
	if (tmp >= 0 && tmp <= 23) {
	get_time(NVRAM, &tm);
	tm.tm_hour = tmp;
	set_time(NVRAM, &tm);
	}
	break;
	case 0x1FFC:
	case 0x07FC:
	/* day of the week / century */
	tmp = from_bcd(val & 0x07);
	get_time(NVRAM, &tm);
	tm.tm_wday = tmp;
	set_time(NVRAM, &tm);
	NVRAM->buffer[addr] = val & 0x40;
	break;
	case 0x1FFD:
	case 0x07FD:
	/* date (BCD) */
	tmp = from_bcd(val & 0x3F);
	if (tmp != 0) {
	get_time(NVRAM, &tm);
	tm.tm_mday = tmp;
	set_time(NVRAM, &tm);
	}
	break;
	case 0x1FFE:
	case 0x07FE:
	/* month */
	tmp = from_bcd(val & 0x1F);
	if (tmp >= 1 && tmp <= 12) {
	get_time(NVRAM, &tm);
	tm.tm_mon = tmp - 1;
	set_time(NVRAM, &tm);
	}
	break;
	case 0x1FFF:
	case 0x07FF:
	/* year */
	tmp = from_bcd(val);
	if (tmp >= 0 && tmp <= 99) {
	get_time(NVRAM, &tm);
	tm.tm_year = from_bcd(val) + NVRAM->base_year - 1900;
	set_time(NVRAM, &tm);
	}
	break;
	default:
	/* Check lock registers state */
	if (addr >= 0x20 && addr <= 0x2F && (NVRAM->lock & 1))
	break;
	if (addr >= 0x30 && addr <= 0x3F && (NVRAM->lock & 2))
	break;
	do_write:
	if (addr < NVRAM->size) {
	NVRAM->buffer[addr] = val & 0xFF;
	}
	break;
	}
	}

	uint32_t m48t59_read(M48t59State *NVRAM, uint32_t addr)
	{
	struct tm tm;
	uint32_t retval = 0xFF;

	/* check for NVRAM access */
	if ((NVRAM->model == 2 && addr < 0x078f) \|\|
	(NVRAM->model == 8 && addr < 0x1ff8) \|\|
	(NVRAM->model == 59 && addr < 0x1ff0)) {
	goto do_read;
	}

	/* TOD access */
	switch (addr) {
	case 0x1FF0:
	/* flags register */
	goto do_read;
	case 0x1FF1:
	/* unused */
	retval = 0;
	break;
	case 0x1FF2:
	/* alarm seconds */
	goto do_read;
	case 0x1FF3:
	/* alarm minutes */
	goto do_read;
	case 0x1FF4:
	/* alarm hours */
	goto do_read;
	case 0x1FF5:
	/* alarm date */
	goto do_read;
	case 0x1FF6:
	/* interrupts */
	goto do_read;
	case 0x1FF7:
	/* A read resets the watchdog */
	set_up_watchdog(NVRAM, NVRAM->buffer[0x1FF7]);
	goto do_read;
	case 0x1FF8:
	case 0x07F8:
	/* control */
	goto do_read;
	case 0x1FF9:
	case 0x07F9:
	/* seconds (BCD) */
	get_time(NVRAM, &tm);
	retval = (NVRAM->buffer[addr] & 0x80) \| to_bcd(tm.tm_sec);
	break;
	case 0x1FFA:
	case 0x07FA:
	/* minutes (BCD) */
	get_time(NVRAM, &tm);
	retval = to_bcd(tm.tm_min);
	break;
	case 0x1FFB:
	case 0x07FB:
	/* hours (BCD) */
	get_time(NVRAM, &tm);
	retval = to_bcd(tm.tm_hour);
	break;
	case 0x1FFC:
	case 0x07FC:
	/* day of the week / century */
	get_time(NVRAM, &tm);
	retval = NVRAM->buffer[addr] \| tm.tm_wday;
	break;
	case 0x1FFD:
	case 0x07FD:
	/* date */
	get_time(NVRAM, &tm);
	retval = to_bcd(tm.tm_mday);
	break;
	case 0x1FFE:
	case 0x07FE:
	/* month */
	get_time(NVRAM, &tm);
	retval = to_bcd(tm.tm_mon + 1);
	break;
	case 0x1FFF:
	case 0x07FF:
	/* year */
	get_time(NVRAM, &tm);
	retval = to_bcd((tm.tm_year + 1900 - NVRAM->base_year) % 100);
	break;
	default:
	/* Check lock registers state */
	if (addr >= 0x20 && addr <= 0x2F && (NVRAM->lock & 1))
	break;
	if (addr >= 0x30 && addr <= 0x3F && (NVRAM->lock & 2))
	break;
	do_read:
	if (addr < NVRAM->size) {
	retval = NVRAM->buffer[addr];
	}
	break;
	}
	trace_m48txx_nvram_mem_read(addr, retval);

	return retval;
	}

	/* IO access to NVRAM */
	static void NVRAM_writeb(void *opaque, hwaddr addr, uint64_t val,
	unsigned size)
	{
	M48t59State *NVRAM = opaque;

	trace_m48txx_nvram_io_write(addr, val);
	switch (addr) {
	case 0:
	NVRAM->addr &= ~0x00FF;
	NVRAM->addr \|= val;
	break;
	case 1:
	NVRAM->addr &= ~0xFF00;
	NVRAM->addr \|= val << 8;
	break;
	case 3:
	m48t59_write(NVRAM, NVRAM->addr, val);
	NVRAM->addr = 0x0000;
	break;
	default:
	break;
	}
	}

	static uint64_t NVRAM_readb(void *opaque, hwaddr addr, unsigned size)
	{
	M48t59State *NVRAM = opaque;
	uint32_t retval;

	switch (addr) {
	case 3:
	retval = m48t59_read(NVRAM, NVRAM->addr);
	break;
	default:
	retval = -1;
	break;
	}
	trace_m48txx_nvram_io_read(addr, retval);

	return retval;
	}

	static uint64_t nvram_read(void *opaque, hwaddr addr, unsigned size)
	{
	M48t59State *NVRAM = opaque;

	return m48t59_read(NVRAM, addr);
	}

	static void nvram_write(void *opaque, hwaddr addr, uint64_t value,
	unsigned size)
	{
	M48t59State *NVRAM = opaque;

	return m48t59_write(NVRAM, addr, value);
	}

	static const MemoryRegionOps nvram_ops = {
	.read = nvram_read,
	.write = nvram_write,
	.impl.min_access_size = 1,
	.impl.max_access_size = 1,
	.valid.min_access_size = 1,
	.valid.max_access_size = 4,
	.endianness = DEVICE_BIG_ENDIAN,
	};

	static const VMStateDescription vmstate_m48t59 = {
	.name = "m48t59",
	.version_id = 1,
	.minimum_version_id = 1,
	.fields = (const VMStateField[]) {
	VMSTATE_UINT8(lock, M48t59State),
	VMSTATE_UINT16(addr, M48t59State),
	VMSTATE_VBUFFER_UINT32(buffer, M48t59State, 0, NULL, size),
	VMSTATE_END_OF_LIST()
	}
	};

	void m48t59_reset_common(M48t59State *NVRAM)
	{
	NVRAM->addr = 0;
	NVRAM->lock = 0;
	if (NVRAM->alrm_timer != NULL)
	timer_del(NVRAM->alrm_timer);

	if (NVRAM->wd_timer != NULL)
	timer_del(NVRAM->wd_timer);
	}

	static void m48t59_reset_sysbus(DeviceState *d)
	{
	M48txxSysBusState *sys = M48TXX_SYS_BUS(d);
	M48t59State *NVRAM = &sys->state;

	m48t59_reset_common(NVRAM);
	}

	const MemoryRegionOps m48t59_io_ops = {
	.read = NVRAM_readb,
	.write = NVRAM_writeb,
	.impl = {
	.min_access_size = 1,
	.max_access_size = 1,
	},
	.endianness = DEVICE_LITTLE_ENDIAN,
	};

	void m48t59_realize_common(M48t59State s, Error *errp)
	{
	s->buffer = g_malloc0(s->size);
	if (s->model == 59) {
	s->alrm_timer = timer_new_ns(rtc_clock, &alarm_cb, s);
	s->wd_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, &watchdog_cb, s);
	}
	qemu_get_timedate(&s->alarm, 0);
	}

	static void m48t59_init1(Object *obj)
	{
	M48txxSysBusDeviceClass *u = M48TXX_SYS_BUS_GET_CLASS(obj);
	M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
	SysBusDevice *dev = SYS_BUS_DEVICE(obj);
	M48t59State *s = &d->state;

	s->model = u->info.model;
	s->size = u->info.size;
	sysbus_init_irq(dev, &s->IRQ);

	memory_region_init_io(&s->iomem, obj, &nvram_ops, s, "m48t59.nvram",
	s->size);
	memory_region_init_io(&d->io, obj, &m48t59_io_ops, s, "m48t59", 4);
	}

	static void m48t59_realize(DeviceState dev, Error *errp)
	{
	M48txxSysBusState *d = M48TXX_SYS_BUS(dev);
	M48t59State *s = &d->state;
	SysBusDevice *sbd = SYS_BUS_DEVICE(dev);

	sysbus_init_mmio(sbd, &s->iomem);
	sysbus_init_mmio(sbd, &d->io);
	m48t59_realize_common(s, errp);
	}

	static uint32_t m48txx_sysbus_read(Nvram *obj, uint32_t addr)
	{
	M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
	return m48t59_read(&d->state, addr);
	}

	static void m48txx_sysbus_write(Nvram *obj, uint32_t addr, uint32_t val)
	{
	M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
	m48t59_write(&d->state, addr, val);
	}

	static void m48txx_sysbus_toggle_lock(Nvram *obj, int lock)
	{
	M48txxSysBusState *d = M48TXX_SYS_BUS(obj);
	m48t59_toggle_lock(&d->state, lock);
	}

	static Property m48t59_sysbus_properties[] = {
	DEFINE_PROP_INT32("base-year", M48txxSysBusState, state.base_year, 0),
	DEFINE_PROP_END_OF_LIST(),
	};

	static void m48txx_sysbus_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);
	NvramClass *nc = NVRAM_CLASS(klass);

	dc->realize = m48t59_realize;
	device_class_set_legacy_reset(dc, m48t59_reset_sysbus);
	device_class_set_props(dc, m48t59_sysbus_properties);
	dc->vmsd = &vmstate_m48t59;
	nc->read = m48txx_sysbus_read;
	nc->write = m48txx_sysbus_write;
	nc->toggle_lock = m48txx_sysbus_toggle_lock;
	}

	static void m48txx_sysbus_concrete_class_init(ObjectClass klass, void data)
	{
	M48txxSysBusDeviceClass *u = M48TXX_SYS_BUS_CLASS(klass);
	M48txxInfo *info = data;

	u->info = *info;
	}

	static const TypeInfo nvram_info = {
	.name = TYPE_NVRAM,
	.parent = TYPE_INTERFACE,
	.class_size = sizeof(NvramClass),
	};

	static const TypeInfo m48txx_sysbus_type_info = {
	.name = TYPE_M48TXX_SYS_BUS,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(M48txxSysBusState),
	.instance_init = m48t59_init1,
	.abstract = true,
	.class_init = m48txx_sysbus_class_init,
	.interfaces = (InterfaceInfo[]) {
	{ TYPE_NVRAM },
	{ }
	}
	};

	static void m48t59_register_types(void)
	{
	TypeInfo sysbus_type_info = {
	.parent = TYPE_M48TXX_SYS_BUS,
	.class_size = sizeof(M48txxSysBusDeviceClass),
	.class_init = m48txx_sysbus_concrete_class_init,
	};
	int i;

	type_register_static(&nvram_info);
	type_register_static(&m48txx_sysbus_type_info);

	for (i = 0; i < ARRAY_SIZE(m48txx_sysbus_info); i++) {
	sysbus_type_info.name = m48txx_sysbus_info[i].bus_name;
	sysbus_type_info.class_data = &m48txx_sysbus_info[i];
	type_register(&sysbus_type_info);
	}
	}

	type_init(m48t59_register_types)