include/hw/watchdog/cmsdk-apb-watchdog.h

   1 /*
   2  * ARM CMSDK APB watchdog emulation
   3  *
   4  * Copyright (c) 2018 Linaro Limited
   5  * Written by Peter Maydell
   6  *
   7  *  This program is free software; you can redistribute it and/or modify
   8  *  it under the terms of the GNU General Public License version 2 or
   9  *  (at your option) any later version.
  10  */
  11
  12 /*
  13  * This is a model of the "APB watchdog" which is part of the Cortex-M
  14  * System Design Kit (CMSDK) and documented in the Cortex-M System
  15  * Design Kit Technical Reference Manual (ARM DDI0479C):
  16  * https://developer.arm.com/products/system-design/system-design-kits/cortex-m-system-design-kit
  17  *
  18  * QEMU interface:
  19  *  + QOM property "wdogclk-frq": frequency at which the watchdog is clocked
  20  *  + sysbus MMIO region 0: the register bank
  21  *  + sysbus IRQ 0: watchdog interrupt
  22  *
  23  * In real hardware the watchdog's reset output is just a GPIO line
  24  * which can then be masked by the board or treated as a simple interrupt.
  25  * (For instance the IoTKit does this with the non-secure watchdog, so that
  26  * secure code can control whether non-secure code can perform a system
  27  * reset via its watchdog.) In QEMU, we just wire up the watchdog reset
  28  * to watchdog_perform_action(), at least for the moment.
  29  */
  30
  31 #ifndef CMSDK_APB_WATCHDOG_H
  32 #define CMSDK_APB_WATCHDOG_H
  33
  34 #include "hw/sysbus.h"
  35 #include "hw/ptimer.h"
  36 #include "qom/object.h"
  37
  38 #define TYPE_CMSDK_APB_WATCHDOG "cmsdk-apb-watchdog"
  39 OBJECT_DECLARE_SIMPLE_TYPE(CMSDKAPBWatchdog, CMSDK_APB_WATCHDOG)
  40
  41 /*
  42  * This shares the same struct (and cast macro) as the base
  43  * cmsdk-apb-watchdog device.
  44  */
  45 #define TYPE_LUMINARY_WATCHDOG "luminary-watchdog"
  46
  47 struct CMSDKAPBWatchdog {
  48     /*< private >*/
  49     SysBusDevice parent_obj;
  50
  51     /*< public >*/
  52     MemoryRegion iomem;
  53     qemu_irq wdogint;
  54     uint32_t wdogclk_frq;
  55     bool is_luminary;
  56     struct ptimer_state *timer;
  57
  58     uint32_t control;
  59     uint32_t intstatus;
  60     uint32_t lock;
  61     uint32_t itcr;
  62     uint32_t itop;
  63     uint32_t resetstatus;
  64     const uint32_t *id;
  65 };
  66
  67 #endif