LXR qemu/hw/misc/bcm2835

   1/*
   2 * BCM2835 dummy thermal sensor
   3 *
   4 * Copyright (C) 2019 Philippe Mathieu-Daudé <f4bug@amsat.org>
   5 *
   6 * SPDX-License-Identifier: GPL-2.0-or-later
   7 */
   8
   9#include "qemu/osdep.h"
  10#include "qemu/log.h"
  11#include "qapi/error.h"
  12#include "hw/misc/bcm2835_thermal.h"
  13#include "hw/registerfields.h"
  14#include "migration/vmstate.h"
  15
  16REG32(CTL, 0)
  17FIELD(CTL, POWER_DOWN, 0, 1)
  18FIELD(CTL, RESET, 1, 1)
  19FIELD(CTL, BANDGAP_CTRL, 2, 3)
  20FIELD(CTL, INTERRUPT_ENABLE, 5, 1)
  21FIELD(CTL, DIRECT, 6, 1)
  22FIELD(CTL, INTERRUPT_CLEAR, 7, 1)
  23FIELD(CTL, HOLD, 8, 10)
  24FIELD(CTL, RESET_DELAY, 18, 8)
  25FIELD(CTL, REGULATOR_ENABLE, 26, 1)
  26
  27REG32(STAT, 4)
  28FIELD(STAT, DATA, 0, 10)
  29FIELD(STAT, VALID, 10, 1)
  30FIELD(STAT, INTERRUPT, 11, 1)
  31
  32#define THERMAL_OFFSET_C 412
  33#define THERMAL_COEFF  (-0.538f)
  34
  35static uint16_t bcm2835_thermal_temp2adc(int temp_C)
  36{
  37    return (temp_C - THERMAL_OFFSET_C) / THERMAL_COEFF;
  38}
  39
  40static uint64_t bcm2835_thermal_read(void *opaque, hwaddr addr, unsigned size)
  41{
  42    Bcm2835ThermalState *s = BCM2835_THERMAL(opaque);
  43    uint32_t val = 0;
  44
  45    switch (addr) {
  46    case A_CTL:
  47        val = s->ctl;
  48        break;
  49    case A_STAT:
  50        /* Temperature is constantly 25°C. */
  51        val = FIELD_DP32(bcm2835_thermal_temp2adc(25), STAT, VALID, true);
  52        break;
  53    default:
  54        /* MemoryRegionOps are aligned, so this can not happen. */
  55        g_assert_not_reached();
  56    }
  57    return val;
  58}
  59
  60static void bcm2835_thermal_write(void *opaque, hwaddr addr,
  61                                  uint64_t value, unsigned size)
  62{
  63    Bcm2835ThermalState *s = BCM2835_THERMAL(opaque);
  64
  65    switch (addr) {
  66    case A_CTL:
  67        s->ctl = value;
  68        break;
  69    case A_STAT:
  70        qemu_log_mask(LOG_GUEST_ERROR, "%s: write 0x%" PRIx64
  71                                       " to 0x%" HWADDR_PRIx "\n",
  72                       __func__, value, addr);
  73        break;
  74    default:
  75        /* MemoryRegionOps are aligned, so this can not happen. */
  76        g_assert_not_reached();
  77    }
  78}
  79
  80static const MemoryRegionOps bcm2835_thermal_ops = {
  81    .read = bcm2835_thermal_read,
  82    .write = bcm2835_thermal_write,
  83    .impl.max_access_size = 4,
  84    .valid.min_access_size = 4,
  85    .endianness = DEVICE_NATIVE_ENDIAN,
  86};
  87
  88static void bcm2835_thermal_reset(DeviceState *dev)
  89{
  90    Bcm2835ThermalState *s = BCM2835_THERMAL(dev);
  91
  92    s->ctl = 0;
  93}
  94
  95static void bcm2835_thermal_realize(DeviceState *dev, Error **errp)
  96{
  97    Bcm2835ThermalState *s = BCM2835_THERMAL(dev);
  98
  99    memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_thermal_ops,
 100                          s, TYPE_BCM2835_THERMAL, 8);
 101    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
 102}
 103
 104static const VMStateDescription bcm2835_thermal_vmstate = {
 105    .name = "bcm2835_thermal",
 106    .version_id = 1,
 107    .minimum_version_id = 1,
 108    .fields = (VMStateField[]) {
 109        VMSTATE_UINT32(ctl, Bcm2835ThermalState),
 110        VMSTATE_END_OF_LIST()
 111    }
 112};
 113
 114static void bcm2835_thermal_class_init(ObjectClass *klass, void *data)
 115{
 116    DeviceClass *dc = DEVICE_CLASS(klass);
 117
 118    dc->realize = bcm2835_thermal_realize;
 119    dc->reset = bcm2835_thermal_reset;
 120    dc->vmsd = &bcm2835_thermal_vmstate;
 121}
 122
 123static const TypeInfo bcm2835_thermal_info = {
 124    .name = TYPE_BCM2835_THERMAL,
 125    .parent = TYPE_SYS_BUS_DEVICE,
 126    .instance_size = sizeof(Bcm2835ThermalState),
 127    .class_init = bcm2835_thermal_class_init,
 128};
 129
 130static void bcm2835_thermal_register_types(void)
 131{
 132    type_register_static(&bcm2835_thermal_info);
 133}
 134
 135type_init(bcm2835_thermal_register_types)
 136