hw/watchdog/cmsdk-apb-watchdog.c - third_party/qemu - Git at Google

 /*
  * ARM CMSDK APB watchdog emulation
  *
  * Copyright (c) 2018 Linaro Limited
  * Written by Peter Maydell
  *
  *  This program is free software; you can redistribute it and/or modify
  *  it under the terms of the GNU General Public License version 2 or
  *  (at your option) any later version.
  */

 /*
  * This is a model of the "APB watchdog" which is part of the Cortex-M
  * System Design Kit (CMSDK) and documented in the Cortex-M System
  * Design Kit Technical Reference Manual (ARM DDI0479C):
  * https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit
  *
  * We also support the variant of this device found in the TI
  * Stellaris/Luminary boards and documented in:
  * http://www.ti.com/lit/ds/symlink/lm3s6965.pdf
  */

 #include "qemu/osdep.h"
 #include "qemu/log.h"
 #include "trace.h"
 #include "qapi/error.h"
 #include "qemu/module.h"
 #include "sysemu/watchdog.h"
 #include "hw/sysbus.h"
 #include "hw/irq.h"
 #include "hw/qdev-properties.h"
 #include "hw/registerfields.h"
 #include "hw/qdev-clock.h"
 #include "hw/watchdog/cmsdk-apb-watchdog.h"
 #include "migration/vmstate.h"

 REG32(WDOGLOAD, 0x0)
 REG32(WDOGVALUE, 0x4)
 REG32(WDOGCONTROL, 0x8)
     FIELD(WDOGCONTROL, INTEN, 0, 1)
     FIELD(WDOGCONTROL, RESEN, 1, 1)
 #define R_WDOGCONTROL_VALID_MASK (R_WDOGCONTROL_INTEN_MASK | \
                                   R_WDOGCONTROL_RESEN_MASK)
 REG32(WDOGINTCLR, 0xc)
 REG32(WDOGRIS, 0x10)
     FIELD(WDOGRIS, INT, 0, 1)
 REG32(WDOGMIS, 0x14)
 REG32(WDOGTEST, 0x418) /* only in Stellaris/Luminary version of the device */
 REG32(WDOGLOCK, 0xc00)
 #define WDOG_UNLOCK_VALUE 0x1ACCE551
 REG32(WDOGITCR, 0xf00)
     FIELD(WDOGITCR, ENABLE, 0, 1)
 #define R_WDOGITCR_VALID_MASK R_WDOGITCR_ENABLE_MASK
 REG32(WDOGITOP, 0xf04)
     FIELD(WDOGITOP, WDOGRES, 0, 1)
     FIELD(WDOGITOP, WDOGINT, 1, 1)
 #define R_WDOGITOP_VALID_MASK (R_WDOGITOP_WDOGRES_MASK | \
                                R_WDOGITOP_WDOGINT_MASK)
 REG32(PID4, 0xfd0)
 REG32(PID5, 0xfd4)
 REG32(PID6, 0xfd8)
 REG32(PID7, 0xfdc)
 REG32(PID0, 0xfe0)
 REG32(PID1, 0xfe4)
 REG32(PID2, 0xfe8)
 REG32(PID3, 0xfec)
 REG32(CID0, 0xff0)
 REG32(CID1, 0xff4)
 REG32(CID2, 0xff8)
 REG32(CID3, 0xffc)

 /* PID/CID values */
 static const uint32_t cmsdk_apb_watchdog_id[] = {
     0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */
     0x24, 0xb8, 0x1b, 0x00, /* PID0..PID3 */
     0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
 };

 static const uint32_t luminary_watchdog_id[] = {
     0x00, 0x00, 0x00, 0x00, /* PID4..PID7 */
     0x05, 0x18, 0x18, 0x01, /* PID0..PID3 */
     0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
 };

 static bool cmsdk_apb_watchdog_intstatus(CMSDKAPBWatchdog *s)
 {
     /* Return masked interrupt status */
     return s->intstatus && (s->control & R_WDOGCONTROL_INTEN_MASK);
 }

 static bool cmsdk_apb_watchdog_resetstatus(CMSDKAPBWatchdog *s)
 {
     /* Return masked reset status */
     return s->resetstatus && (s->control & R_WDOGCONTROL_RESEN_MASK);
 }

 static void cmsdk_apb_watchdog_update(CMSDKAPBWatchdog *s)
 {
     bool wdogint;
     bool wdogres;

     if (s->itcr) {
         /*
          * Not checking that !s->is_luminary since s->itcr can't be written
          * when s->is_luminary in the first place.
          */
         wdogint = s->itop & R_WDOGITOP_WDOGINT_MASK;
         wdogres = s->itop & R_WDOGITOP_WDOGRES_MASK;
     } else {
         wdogint = cmsdk_apb_watchdog_intstatus(s);
         wdogres = cmsdk_apb_watchdog_resetstatus(s);
     }

     qemu_set_irq(s->wdogint, wdogint);
     if (wdogres) {
         watchdog_perform_action();
     }
 }

 static uint64_t cmsdk_apb_watchdog_read(void *opaque, hwaddr offset,
                                         unsigned size)
 {
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);
     uint64_t r;

     switch (offset) {
     case A_WDOGLOAD:
         r = ptimer_get_limit(s->timer);
         break;
     case A_WDOGVALUE:
         r = ptimer_get_count(s->timer);
         break;
     case A_WDOGCONTROL:
         r = s->control;
         break;
     case A_WDOGRIS:
         r = s->intstatus;
         break;
     case A_WDOGMIS:
         r = cmsdk_apb_watchdog_intstatus(s);
         break;
     case A_WDOGLOCK:
         r = s->lock;
         break;
     case A_WDOGITCR:
         if (s->is_luminary) {
             goto bad_offset;
         }
         r = s->itcr;
         break;
     case A_PID4 ... A_CID3:
         r = s->id[(offset - A_PID4) / 4];
         break;
     case A_WDOGINTCLR:
     case A_WDOGITOP:
         if (s->is_luminary) {
             goto bad_offset;
         }
         qemu_log_mask(LOG_GUEST_ERROR,
                       "CMSDK APB watchdog read: read of WO offset %x\n",
                       (int)offset);
         r = 0;
         break;
     case A_WDOGTEST:
         if (!s->is_luminary) {
             goto bad_offset;
         }
         qemu_log_mask(LOG_UNIMP,
                       "Luminary watchdog read: stall not implemented\n");
         r = 0;
         break;
     default:
 bad_offset:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "CMSDK APB watchdog read: bad offset %x\n", (int)offset);
         r = 0;
         break;
     }
     trace_cmsdk_apb_watchdog_read(offset, r, size);
     return r;
 }

 static void cmsdk_apb_watchdog_write(void *opaque, hwaddr offset,
                                      uint64_t value, unsigned size)
 {
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);

     trace_cmsdk_apb_watchdog_write(offset, value, size);

     if (s->lock && offset != A_WDOGLOCK) {
         /* Write access is disabled via WDOGLOCK */
         qemu_log_mask(LOG_GUEST_ERROR,
                       "CMSDK APB watchdog write: write to locked watchdog\n");
         return;
     }

     switch (offset) {
     case A_WDOGLOAD:
         /*
          * Reset the load value and the current count, and make sure
          * we're counting.
          */
         ptimer_transaction_begin(s->timer);
         ptimer_set_limit(s->timer, value, 1);
         ptimer_run(s->timer, 0);
         ptimer_transaction_commit(s->timer);
         break;
     case A_WDOGCONTROL:
         if (s->is_luminary && 0 != (R_WDOGCONTROL_INTEN_MASK & s->control)) {
             /*
              * The Luminary version of this device ignores writes to
              * this register after the guest has enabled interrupts
              * (so they can only be disabled again via reset).
              */
             break;
         }
         s->control = value & R_WDOGCONTROL_VALID_MASK;
         cmsdk_apb_watchdog_update(s);
         break;
     case A_WDOGINTCLR:
         s->intstatus = 0;
         ptimer_transaction_begin(s->timer);
         ptimer_set_count(s->timer, ptimer_get_limit(s->timer));
         ptimer_transaction_commit(s->timer);
         cmsdk_apb_watchdog_update(s);
         break;
     case A_WDOGLOCK:
         s->lock = (value != WDOG_UNLOCK_VALUE);
         trace_cmsdk_apb_watchdog_lock(s->lock);
         break;
     case A_WDOGITCR:
         if (s->is_luminary) {
             goto bad_offset;
         }
         s->itcr = value & R_WDOGITCR_VALID_MASK;
         cmsdk_apb_watchdog_update(s);
         break;
     case A_WDOGITOP:
         if (s->is_luminary) {
             goto bad_offset;
         }
         s->itop = value & R_WDOGITOP_VALID_MASK;
         cmsdk_apb_watchdog_update(s);
         break;
     case A_WDOGVALUE:
     case A_WDOGRIS:
     case A_WDOGMIS:
     case A_PID4 ... A_CID3:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "CMSDK APB watchdog write: write to RO offset 0x%x\n",
                       (int)offset);
         break;
     case A_WDOGTEST:
         if (!s->is_luminary) {
             goto bad_offset;
         }
         qemu_log_mask(LOG_UNIMP,
                       "Luminary watchdog write: stall not implemented\n");
         break;
     default:
 bad_offset:
         qemu_log_mask(LOG_GUEST_ERROR,
                       "CMSDK APB watchdog write: bad offset 0x%x\n",
                       (int)offset);
         break;
     }
 }

 static const MemoryRegionOps cmsdk_apb_watchdog_ops = {
     .read = cmsdk_apb_watchdog_read,
     .write = cmsdk_apb_watchdog_write,
     .endianness = DEVICE_LITTLE_ENDIAN,
     /* byte/halfword accesses are just zero-padded on reads and writes */
     .impl.min_access_size = 4,
     .impl.max_access_size = 4,
     .valid.min_access_size = 1,
     .valid.max_access_size = 4,
 };

 static void cmsdk_apb_watchdog_tick(void *opaque)
 {
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);

     if (!s->intstatus) {
         /* Count expired for the first time: raise interrupt */
         s->intstatus = R_WDOGRIS_INT_MASK;
     } else {
         /* Count expired for the second time: raise reset and stop clock */
         s->resetstatus = 1;
         ptimer_stop(s->timer);
     }
     cmsdk_apb_watchdog_update(s);
 }

 static void cmsdk_apb_watchdog_reset(DeviceState *dev)
 {
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(dev);

     trace_cmsdk_apb_watchdog_reset();
     s->control = 0;
     s->intstatus = 0;
     s->lock = 0;
     s->itcr = 0;
     s->itop = 0;
     s->resetstatus = 0;
     /* Set the limit and the count */
     ptimer_transaction_begin(s->timer);
     ptimer_set_limit(s->timer, 0xffffffff, 1);
     ptimer_run(s->timer, 0);
     ptimer_transaction_commit(s->timer);
 }

 static void cmsdk_apb_watchdog_clk_update(void *opaque, ClockEvent event)
 {
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);

     ptimer_transaction_begin(s->timer);
     ptimer_set_period_from_clock(s->timer, s->wdogclk, 1);
     ptimer_transaction_commit(s->timer);
 }

 static void cmsdk_apb_watchdog_init(Object *obj)
 {
     SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(obj);

     memory_region_init_io(&s->iomem, obj, &cmsdk_apb_watchdog_ops,
                           s, "cmsdk-apb-watchdog", 0x1000);
     sysbus_init_mmio(sbd, &s->iomem);
     sysbus_init_irq(sbd, &s->wdogint);
     s->wdogclk = qdev_init_clock_in(DEVICE(s), "WDOGCLK",
                                     cmsdk_apb_watchdog_clk_update, s,
                                     ClockUpdate);

     s->is_luminary = false;
     s->id = cmsdk_apb_watchdog_id;
 }

 static void cmsdk_apb_watchdog_realize(DeviceState *dev, Error **errp)
 {
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(dev);

     if (!clock_has_source(s->wdogclk)) {
         error_setg(errp,
                    "CMSDK APB watchdog: WDOGCLK clock must be connected");
         return;
     }

     s->timer = ptimer_init(cmsdk_apb_watchdog_tick, s,
                            PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD |
                            PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT |
                            PTIMER_POLICY_NO_IMMEDIATE_RELOAD |
                            PTIMER_POLICY_NO_COUNTER_ROUND_DOWN);

     ptimer_transaction_begin(s->timer);
     ptimer_set_period_from_clock(s->timer, s->wdogclk, 1);
     ptimer_transaction_commit(s->timer);
 }

 static const VMStateDescription cmsdk_apb_watchdog_vmstate = {
     .name = "cmsdk-apb-watchdog",
     .version_id = 2,
     .minimum_version_id = 2,
     .fields = (VMStateField[]) {
         VMSTATE_CLOCK(wdogclk, CMSDKAPBWatchdog),
         VMSTATE_PTIMER(timer, CMSDKAPBWatchdog),
         VMSTATE_UINT32(control, CMSDKAPBWatchdog),
         VMSTATE_UINT32(intstatus, CMSDKAPBWatchdog),
         VMSTATE_UINT32(lock, CMSDKAPBWatchdog),
         VMSTATE_UINT32(itcr, CMSDKAPBWatchdog),
         VMSTATE_UINT32(itop, CMSDKAPBWatchdog),
         VMSTATE_UINT32(resetstatus, CMSDKAPBWatchdog),
         VMSTATE_END_OF_LIST()
     }
 };

 static void cmsdk_apb_watchdog_class_init(ObjectClass *klass, void *data)
 {
     DeviceClass *dc = DEVICE_CLASS(klass);

     dc->realize = cmsdk_apb_watchdog_realize;
     dc->vmsd = &cmsdk_apb_watchdog_vmstate;
     dc->reset = cmsdk_apb_watchdog_reset;
 }

 static const TypeInfo cmsdk_apb_watchdog_info = {
     .name = TYPE_CMSDK_APB_WATCHDOG,
     .parent = TYPE_SYS_BUS_DEVICE,
     .instance_size = sizeof(CMSDKAPBWatchdog),
     .instance_init = cmsdk_apb_watchdog_init,
     .class_init = cmsdk_apb_watchdog_class_init,
 };

 static void luminary_watchdog_init(Object *obj)
 {
     CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(obj);

     s->is_luminary = true;
     s->id = luminary_watchdog_id;
 }

 static const TypeInfo luminary_watchdog_info = {
     .name = TYPE_LUMINARY_WATCHDOG,
     .parent = TYPE_CMSDK_APB_WATCHDOG,
     .instance_init = luminary_watchdog_init
 };

 static void cmsdk_apb_watchdog_register_types(void)
 {
     type_register_static(&cmsdk_apb_watchdog_info);
     type_register_static(&luminary_watchdog_info);
 }

 type_init(cmsdk_apb_watchdog_register_types);
	/*
	* ARM CMSDK APB watchdog emulation
	*
	* Copyright (c) 2018 Linaro Limited
	* Written by Peter Maydell
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 or
	* (at your option) any later version.
	*/

	/*
	* This is a model of the "APB watchdog" which is part of the Cortex-M
	* System Design Kit (CMSDK) and documented in the Cortex-M System
	* Design Kit Technical Reference Manual (ARM DDI0479C):
	* https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit
	*
	* We also support the variant of this device found in the TI
	* Stellaris/Luminary boards and documented in:
	* http://www.ti.com/lit/ds/symlink/lm3s6965.pdf
	*/

	#include "qemu/osdep.h"
	#include "qemu/log.h"
	#include "trace.h"
	#include "qapi/error.h"
	#include "qemu/module.h"
	#include "sysemu/watchdog.h"
	#include "hw/sysbus.h"
	#include "hw/irq.h"
	#include "hw/qdev-properties.h"
	#include "hw/registerfields.h"
	#include "hw/qdev-clock.h"
	#include "hw/watchdog/cmsdk-apb-watchdog.h"
	#include "migration/vmstate.h"

	REG32(WDOGLOAD, 0x0)
	REG32(WDOGVALUE, 0x4)
	REG32(WDOGCONTROL, 0x8)
	FIELD(WDOGCONTROL, INTEN, 0, 1)
	FIELD(WDOGCONTROL, RESEN, 1, 1)
	#define R_WDOGCONTROL_VALID_MASK (R_WDOGCONTROL_INTEN_MASK \| \
	R_WDOGCONTROL_RESEN_MASK)
	REG32(WDOGINTCLR, 0xc)
	REG32(WDOGRIS, 0x10)
	FIELD(WDOGRIS, INT, 0, 1)
	REG32(WDOGMIS, 0x14)
	REG32(WDOGTEST, 0x418) /* only in Stellaris/Luminary version of the device */
	REG32(WDOGLOCK, 0xc00)
	#define WDOG_UNLOCK_VALUE 0x1ACCE551
	REG32(WDOGITCR, 0xf00)
	FIELD(WDOGITCR, ENABLE, 0, 1)
	#define R_WDOGITCR_VALID_MASK R_WDOGITCR_ENABLE_MASK
	REG32(WDOGITOP, 0xf04)
	FIELD(WDOGITOP, WDOGRES, 0, 1)
	FIELD(WDOGITOP, WDOGINT, 1, 1)
	#define R_WDOGITOP_VALID_MASK (R_WDOGITOP_WDOGRES_MASK \| \
	R_WDOGITOP_WDOGINT_MASK)
	REG32(PID4, 0xfd0)
	REG32(PID5, 0xfd4)
	REG32(PID6, 0xfd8)
	REG32(PID7, 0xfdc)
	REG32(PID0, 0xfe0)
	REG32(PID1, 0xfe4)
	REG32(PID2, 0xfe8)
	REG32(PID3, 0xfec)
	REG32(CID0, 0xff0)
	REG32(CID1, 0xff4)
	REG32(CID2, 0xff8)
	REG32(CID3, 0xffc)

	/* PID/CID values */
	static const uint32_t cmsdk_apb_watchdog_id[] = {
	0x04, 0x00, 0x00, 0x00, /* PID4..PID7 */
	0x24, 0xb8, 0x1b, 0x00, /* PID0..PID3 */
	0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
	};

	static const uint32_t luminary_watchdog_id[] = {
	0x00, 0x00, 0x00, 0x00, /* PID4..PID7 */
	0x05, 0x18, 0x18, 0x01, /* PID0..PID3 */
	0x0d, 0xf0, 0x05, 0xb1, /* CID0..CID3 */
	};

	static bool cmsdk_apb_watchdog_intstatus(CMSDKAPBWatchdog *s)
	{
	/* Return masked interrupt status */
	return s->intstatus && (s->control & R_WDOGCONTROL_INTEN_MASK);
	}

	static bool cmsdk_apb_watchdog_resetstatus(CMSDKAPBWatchdog *s)
	{
	/* Return masked reset status */
	return s->resetstatus && (s->control & R_WDOGCONTROL_RESEN_MASK);
	}

	static void cmsdk_apb_watchdog_update(CMSDKAPBWatchdog *s)
	{
	bool wdogint;
	bool wdogres;

	if (s->itcr) {
	/*
	* Not checking that !s->is_luminary since s->itcr can't be written
	* when s->is_luminary in the first place.
	*/
	wdogint = s->itop & R_WDOGITOP_WDOGINT_MASK;
	wdogres = s->itop & R_WDOGITOP_WDOGRES_MASK;
	} else {
	wdogint = cmsdk_apb_watchdog_intstatus(s);
	wdogres = cmsdk_apb_watchdog_resetstatus(s);
	}

	qemu_set_irq(s->wdogint, wdogint);
	if (wdogres) {
	watchdog_perform_action();
	}
	}

	static uint64_t cmsdk_apb_watchdog_read(void *opaque, hwaddr offset,
	unsigned size)
	{
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);
	uint64_t r;

	switch (offset) {
	case A_WDOGLOAD:
	r = ptimer_get_limit(s->timer);
	break;
	case A_WDOGVALUE:
	r = ptimer_get_count(s->timer);
	break;
	case A_WDOGCONTROL:
	r = s->control;
	break;
	case A_WDOGRIS:
	r = s->intstatus;
	break;
	case A_WDOGMIS:
	r = cmsdk_apb_watchdog_intstatus(s);
	break;
	case A_WDOGLOCK:
	r = s->lock;
	break;
	case A_WDOGITCR:
	if (s->is_luminary) {
	goto bad_offset;
	}
	r = s->itcr;
	break;
	case A_PID4 ... A_CID3:
	r = s->id[(offset - A_PID4) / 4];
	break;
	case A_WDOGINTCLR:
	case A_WDOGITOP:
	if (s->is_luminary) {
	goto bad_offset;
	}
	qemu_log_mask(LOG_GUEST_ERROR,
	"CMSDK APB watchdog read: read of WO offset %x\n",
	(int)offset);
	r = 0;
	break;
	case A_WDOGTEST:
	if (!s->is_luminary) {
	goto bad_offset;
	}
	qemu_log_mask(LOG_UNIMP,
	"Luminary watchdog read: stall not implemented\n");
	r = 0;
	break;
	default:
	bad_offset:
	qemu_log_mask(LOG_GUEST_ERROR,
	"CMSDK APB watchdog read: bad offset %x\n", (int)offset);
	r = 0;
	break;
	}
	trace_cmsdk_apb_watchdog_read(offset, r, size);
	return r;
	}

	static void cmsdk_apb_watchdog_write(void *opaque, hwaddr offset,
	uint64_t value, unsigned size)
	{
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);

	trace_cmsdk_apb_watchdog_write(offset, value, size);

	if (s->lock && offset != A_WDOGLOCK) {
	/* Write access is disabled via WDOGLOCK */
	qemu_log_mask(LOG_GUEST_ERROR,
	"CMSDK APB watchdog write: write to locked watchdog\n");
	return;
	}

	switch (offset) {
	case A_WDOGLOAD:
	/*
	* Reset the load value and the current count, and make sure
	* we're counting.
	*/
	ptimer_transaction_begin(s->timer);
	ptimer_set_limit(s->timer, value, 1);
	ptimer_run(s->timer, 0);
	ptimer_transaction_commit(s->timer);
	break;
	case A_WDOGCONTROL:
	if (s->is_luminary && 0 != (R_WDOGCONTROL_INTEN_MASK & s->control)) {
	/*
	* The Luminary version of this device ignores writes to
	* this register after the guest has enabled interrupts
	* (so they can only be disabled again via reset).
	*/
	break;
	}
	s->control = value & R_WDOGCONTROL_VALID_MASK;
	cmsdk_apb_watchdog_update(s);
	break;
	case A_WDOGINTCLR:
	s->intstatus = 0;
	ptimer_transaction_begin(s->timer);
	ptimer_set_count(s->timer, ptimer_get_limit(s->timer));
	ptimer_transaction_commit(s->timer);
	cmsdk_apb_watchdog_update(s);
	break;
	case A_WDOGLOCK:
	s->lock = (value != WDOG_UNLOCK_VALUE);
	trace_cmsdk_apb_watchdog_lock(s->lock);
	break;
	case A_WDOGITCR:
	if (s->is_luminary) {
	goto bad_offset;
	}
	s->itcr = value & R_WDOGITCR_VALID_MASK;
	cmsdk_apb_watchdog_update(s);
	break;
	case A_WDOGITOP:
	if (s->is_luminary) {
	goto bad_offset;
	}
	s->itop = value & R_WDOGITOP_VALID_MASK;
	cmsdk_apb_watchdog_update(s);
	break;
	case A_WDOGVALUE:
	case A_WDOGRIS:
	case A_WDOGMIS:
	case A_PID4 ... A_CID3:
	qemu_log_mask(LOG_GUEST_ERROR,
	"CMSDK APB watchdog write: write to RO offset 0x%x\n",
	(int)offset);
	break;
	case A_WDOGTEST:
	if (!s->is_luminary) {
	goto bad_offset;
	}
	qemu_log_mask(LOG_UNIMP,
	"Luminary watchdog write: stall not implemented\n");
	break;
	default:
	bad_offset:
	qemu_log_mask(LOG_GUEST_ERROR,
	"CMSDK APB watchdog write: bad offset 0x%x\n",
	(int)offset);
	break;
	}
	}

	static const MemoryRegionOps cmsdk_apb_watchdog_ops = {
	.read = cmsdk_apb_watchdog_read,
	.write = cmsdk_apb_watchdog_write,
	.endianness = DEVICE_LITTLE_ENDIAN,
	/* byte/halfword accesses are just zero-padded on reads and writes */
	.impl.min_access_size = 4,
	.impl.max_access_size = 4,
	.valid.min_access_size = 1,
	.valid.max_access_size = 4,
	};

	static void cmsdk_apb_watchdog_tick(void *opaque)
	{
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);

	if (!s->intstatus) {
	/* Count expired for the first time: raise interrupt */
	s->intstatus = R_WDOGRIS_INT_MASK;
	} else {
	/* Count expired for the second time: raise reset and stop clock */
	s->resetstatus = 1;
	ptimer_stop(s->timer);
	}
	cmsdk_apb_watchdog_update(s);
	}

	static void cmsdk_apb_watchdog_reset(DeviceState *dev)
	{
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(dev);

	trace_cmsdk_apb_watchdog_reset();
	s->control = 0;
	s->intstatus = 0;
	s->lock = 0;
	s->itcr = 0;
	s->itop = 0;
	s->resetstatus = 0;
	/* Set the limit and the count */
	ptimer_transaction_begin(s->timer);
	ptimer_set_limit(s->timer, 0xffffffff, 1);
	ptimer_run(s->timer, 0);
	ptimer_transaction_commit(s->timer);
	}

	static void cmsdk_apb_watchdog_clk_update(void *opaque, ClockEvent event)
	{
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(opaque);

	ptimer_transaction_begin(s->timer);
	ptimer_set_period_from_clock(s->timer, s->wdogclk, 1);
	ptimer_transaction_commit(s->timer);
	}

	static void cmsdk_apb_watchdog_init(Object *obj)
	{
	SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(obj);

	memory_region_init_io(&s->iomem, obj, &cmsdk_apb_watchdog_ops,
	s, "cmsdk-apb-watchdog", 0x1000);
	sysbus_init_mmio(sbd, &s->iomem);
	sysbus_init_irq(sbd, &s->wdogint);
	s->wdogclk = qdev_init_clock_in(DEVICE(s), "WDOGCLK",
	cmsdk_apb_watchdog_clk_update, s,
	ClockUpdate);

	s->is_luminary = false;
	s->id = cmsdk_apb_watchdog_id;
	}

	static void cmsdk_apb_watchdog_realize(DeviceState dev, Error *errp)
	{
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(dev);

	if (!clock_has_source(s->wdogclk)) {
	error_setg(errp,
	"CMSDK APB watchdog: WDOGCLK clock must be connected");
	return;
	}

	s->timer = ptimer_init(cmsdk_apb_watchdog_tick, s,
	PTIMER_POLICY_WRAP_AFTER_ONE_PERIOD \|
	PTIMER_POLICY_TRIGGER_ONLY_ON_DECREMENT \|
	PTIMER_POLICY_NO_IMMEDIATE_RELOAD \|
	PTIMER_POLICY_NO_COUNTER_ROUND_DOWN);

	ptimer_transaction_begin(s->timer);
	ptimer_set_period_from_clock(s->timer, s->wdogclk, 1);
	ptimer_transaction_commit(s->timer);
	}

	static const VMStateDescription cmsdk_apb_watchdog_vmstate = {
	.name = "cmsdk-apb-watchdog",
	.version_id = 2,
	.minimum_version_id = 2,
	.fields = (VMStateField[]) {
	VMSTATE_CLOCK(wdogclk, CMSDKAPBWatchdog),
	VMSTATE_PTIMER(timer, CMSDKAPBWatchdog),
	VMSTATE_UINT32(control, CMSDKAPBWatchdog),
	VMSTATE_UINT32(intstatus, CMSDKAPBWatchdog),
	VMSTATE_UINT32(lock, CMSDKAPBWatchdog),
	VMSTATE_UINT32(itcr, CMSDKAPBWatchdog),
	VMSTATE_UINT32(itop, CMSDKAPBWatchdog),
	VMSTATE_UINT32(resetstatus, CMSDKAPBWatchdog),
	VMSTATE_END_OF_LIST()
	}
	};

	static void cmsdk_apb_watchdog_class_init(ObjectClass klass, void data)
	{
	DeviceClass *dc = DEVICE_CLASS(klass);

	dc->realize = cmsdk_apb_watchdog_realize;
	dc->vmsd = &cmsdk_apb_watchdog_vmstate;
	dc->reset = cmsdk_apb_watchdog_reset;
	}

	static const TypeInfo cmsdk_apb_watchdog_info = {
	.name = TYPE_CMSDK_APB_WATCHDOG,
	.parent = TYPE_SYS_BUS_DEVICE,
	.instance_size = sizeof(CMSDKAPBWatchdog),
	.instance_init = cmsdk_apb_watchdog_init,
	.class_init = cmsdk_apb_watchdog_class_init,
	};

	static void luminary_watchdog_init(Object *obj)
	{
	CMSDKAPBWatchdog *s = CMSDK_APB_WATCHDOG(obj);

	s->is_luminary = true;
	s->id = luminary_watchdog_id;
	}

	static const TypeInfo luminary_watchdog_info = {
	.name = TYPE_LUMINARY_WATCHDOG,
	.parent = TYPE_CMSDK_APB_WATCHDOG,
	.instance_init = luminary_watchdog_init
	};

	static void cmsdk_apb_watchdog_register_types(void)
	{
	type_register_static(&cmsdk_apb_watchdog_info);
	type_register_static(&luminary_watchdog_info);
	}

	type_init(cmsdk_apb_watchdog_register_types);