LXR qemu/hw/misc/bcm2835

   1/*
   2 * BCM2835 Power Management emulation
   3 *
   4 * Copyright (C) 2017 Marcin Chojnacki <marcinch7@gmail.com>
   5 * Copyright (C) 2021 Nolan Leake <nolan@sigbus.net>
   6 *
   7 * This work is licensed under the terms of the GNU GPL, version 2 or later.
   8 * See the COPYING file in the top-level directory.
   9 */
  10
  11#include "qemu/osdep.h"
  12#include "qemu/log.h"
  13#include "qemu/module.h"
  14#include "hw/misc/bcm2835_powermgt.h"
  15#include "migration/vmstate.h"
  16#include "sysemu/runstate.h"
  17
  18#define PASSWORD 0x5a000000
  19#define PASSWORD_MASK 0xff000000
  20
  21#define R_RSTC 0x1c
  22#define V_RSTC_RESET 0x20
  23#define R_RSTS 0x20
  24#define V_RSTS_POWEROFF 0x555 /* Linux uses partition 63 to indicate halt. */
  25#define R_WDOG 0x24
  26
  27static uint64_t bcm2835_powermgt_read(void *opaque, hwaddr offset,
  28                                      unsigned size)
  29{
  30    BCM2835PowerMgtState *s = (BCM2835PowerMgtState *)opaque;
  31    uint32_t res = 0;
  32
  33    switch (offset) {
  34    case R_RSTC:
  35        res = s->rstc;
  36        break;
  37    case R_RSTS:
  38        res = s->rsts;
  39        break;
  40    case R_WDOG:
  41        res = s->wdog;
  42        break;
  43
  44    default:
  45        qemu_log_mask(LOG_UNIMP,
  46                      "bcm2835_powermgt_read: Unknown offset 0x%08"HWADDR_PRIx
  47                      "\n", offset);
  48        res = 0;
  49        break;
  50    }
  51
  52    return res;
  53}
  54
  55static void bcm2835_powermgt_write(void *opaque, hwaddr offset,
  56                                   uint64_t value, unsigned size)
  57{
  58    BCM2835PowerMgtState *s = (BCM2835PowerMgtState *)opaque;
  59
  60    if ((value & PASSWORD_MASK) != PASSWORD) {
  61        qemu_log_mask(LOG_GUEST_ERROR,
  62                      "bcm2835_powermgt_write: Bad password 0x%"PRIx64
  63                      " at offset 0x%08"HWADDR_PRIx"\n",
  64                      value, offset);
  65        return;
  66    }
  67
  68    value = value & ~PASSWORD_MASK;
  69
  70    switch (offset) {
  71    case R_RSTC:
  72        s->rstc = value;
  73        if (value & V_RSTC_RESET) {
  74            if ((s->rsts & 0xfff) == V_RSTS_POWEROFF) {
  75                qemu_system_shutdown_request(SHUTDOWN_CAUSE_GUEST_SHUTDOWN);
  76            } else {
  77                qemu_system_reset_request(SHUTDOWN_CAUSE_GUEST_RESET);
  78            }
  79        }
  80        break;
  81    case R_RSTS:
  82        qemu_log_mask(LOG_UNIMP,
  83                      "bcm2835_powermgt_write: RSTS\n");
  84        s->rsts = value;
  85        break;
  86    case R_WDOG:
  87        qemu_log_mask(LOG_UNIMP,
  88                      "bcm2835_powermgt_write: WDOG\n");
  89        s->wdog = value;
  90        break;
  91
  92    default:
  93        qemu_log_mask(LOG_UNIMP,
  94                      "bcm2835_powermgt_write: Unknown offset 0x%08"HWADDR_PRIx
  95                      "\n", offset);
  96        break;
  97    }
  98}
  99
 100static const MemoryRegionOps bcm2835_powermgt_ops = {
 101    .read = bcm2835_powermgt_read,
 102    .write = bcm2835_powermgt_write,
 103    .endianness = DEVICE_NATIVE_ENDIAN,
 104    .impl.min_access_size = 4,
 105    .impl.max_access_size = 4,
 106};
 107
 108static const VMStateDescription vmstate_bcm2835_powermgt = {
 109    .name = TYPE_BCM2835_POWERMGT,
 110    .version_id = 1,
 111    .minimum_version_id = 1,
 112    .fields = (VMStateField[]) {
 113        VMSTATE_UINT32(rstc, BCM2835PowerMgtState),
 114        VMSTATE_UINT32(rsts, BCM2835PowerMgtState),
 115        VMSTATE_UINT32(wdog, BCM2835PowerMgtState),
 116        VMSTATE_END_OF_LIST()
 117    }
 118};
 119
 120static void bcm2835_powermgt_init(Object *obj)
 121{
 122    BCM2835PowerMgtState *s = BCM2835_POWERMGT(obj);
 123
 124    memory_region_init_io(&s->iomem, obj, &bcm2835_powermgt_ops, s,
 125                          TYPE_BCM2835_POWERMGT, 0x200);
 126    sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem);
 127}
 128
 129static void bcm2835_powermgt_reset(DeviceState *dev)
 130{
 131    BCM2835PowerMgtState *s = BCM2835_POWERMGT(dev);
 132
 133    /* https://elinux.org/BCM2835_registers#PM */
 134    s->rstc = 0x00000102;
 135    s->rsts = 0x00001000;
 136    s->wdog = 0x00000000;
 137}
 138
 139static void bcm2835_powermgt_class_init(ObjectClass *klass, void *data)
 140{
 141    DeviceClass *dc = DEVICE_CLASS(klass);
 142
 143    dc->reset = bcm2835_powermgt_reset;
 144    dc->vmsd = &vmstate_bcm2835_powermgt;
 145}
 146
 147static const TypeInfo bcm2835_powermgt_info = {
 148    .name          = TYPE_BCM2835_POWERMGT,
 149    .parent        = TYPE_SYS_BUS_DEVICE,
 150    .instance_size = sizeof(BCM2835PowerMgtState),
 151    .class_init    = bcm2835_powermgt_class_init,
 152    .instance_init = bcm2835_powermgt_init,
 153};
 154
 155static void bcm2835_powermgt_register_types(void)
 156{
 157    type_register_static(&bcm2835_powermgt_info);
 158}
 159
 160type_init(bcm2835_powermgt_register_types)
 161