blob: c6f3b1ad605992d229eb6094d27a7945fc8329ea [file] [log] [blame]
Philippe Mathieu-Daudé99c64132019-10-20 01:47:00 +02001/*
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)