LXR qemu/hw/misc/imx2

   1/*
   2 * Copyright (c) 2018, Impinj, Inc.
   3 *
   4 * i.MX2 Watchdog IP block
   5 *
   6 * Author: Andrey Smirnov <andrew.smirnov@gmail.com>
   7 *
   8 * This work is licensed under the terms of the GNU GPL, version 2 or later.
   9 * See the COPYING file in the top-level directory.
  10 */
  11
  12#include "qemu/osdep.h"
  13#include "qemu/bitops.h"
  14#include "qemu/module.h"
  15#include "sysemu/watchdog.h"
  16
  17#include "hw/misc/imx2_wdt.h"
  18
  19#define IMX2_WDT_WCR_WDA    BIT(5)      /* -> External Reset WDOG_B */
  20#define IMX2_WDT_WCR_SRS    BIT(4)      /* -> Software Reset Signal */
  21
  22static uint64_t imx2_wdt_read(void *opaque, hwaddr addr,
  23                              unsigned int size)
  24{
  25    return 0;
  26}
  27
  28static void imx2_wdt_write(void *opaque, hwaddr addr,
  29                           uint64_t value, unsigned int size)
  30{
  31    if (addr == IMX2_WDT_WCR &&
  32        (value & (IMX2_WDT_WCR_WDA | IMX2_WDT_WCR_SRS))) {
  33        watchdog_perform_action();
  34    }
  35}
  36
  37static const MemoryRegionOps imx2_wdt_ops = {
  38    .read  = imx2_wdt_read,
  39    .write = imx2_wdt_write,
  40    .endianness = DEVICE_NATIVE_ENDIAN,
  41    .impl = {
  42        /*
  43         * Our device would not work correctly if the guest was doing
  44         * unaligned access. This might not be a limitation on the
  45         * real device but in practice there is no reason for a guest
  46         * to access this device unaligned.
  47         */
  48        .min_access_size = 4,
  49        .max_access_size = 4,
  50        .unaligned = false,
  51    },
  52};
  53
  54static void imx2_wdt_realize(DeviceState *dev, Error **errp)
  55{
  56    IMX2WdtState *s = IMX2_WDT(dev);
  57
  58    memory_region_init_io(&s->mmio, OBJECT(dev),
  59                          &imx2_wdt_ops, s,
  60                          TYPE_IMX2_WDT".mmio",
  61                          IMX2_WDT_REG_NUM * sizeof(uint16_t));
  62    sysbus_init_mmio(SYS_BUS_DEVICE(dev), &s->mmio);
  63}
  64
  65static void imx2_wdt_class_init(ObjectClass *klass, void *data)
  66{
  67    DeviceClass *dc = DEVICE_CLASS(klass);
  68
  69    dc->realize = imx2_wdt_realize;
  70    set_bit(DEVICE_CATEGORY_MISC, dc->categories);
  71}
  72
  73static const TypeInfo imx2_wdt_info = {
  74    .name          = TYPE_IMX2_WDT,
  75    .parent        = TYPE_SYS_BUS_DEVICE,
  76    .instance_size = sizeof(IMX2WdtState),
  77    .class_init    = imx2_wdt_class_init,
  78};
  79
  80static WatchdogTimerModel model = {
  81    .wdt_name = "imx2-watchdog",
  82    .wdt_description = "i.MX2 Watchdog",
  83};
  84
  85static void imx2_wdt_register_type(void)
  86{
  87    watchdog_add_model(&model);
  88    type_register_static(&imx2_wdt_info);
  89}
  90type_init(imx2_wdt_register_type)
  91