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