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 16 REG32(CTL, 0) 17 FIELD(CTL, POWER_DOWN, 0, 1) 18 FIELD(CTL, RESET, 1, 1) 19 FIELD(CTL, BANDGAP_CTRL, 2, 3) 20 FIELD(CTL, INTERRUPT_ENABLE, 5, 1) 21 FIELD(CTL, DIRECT, 6, 1) 22 FIELD(CTL, INTERRUPT_CLEAR, 7, 1) 23 FIELD(CTL, HOLD, 8, 10) 24 FIELD(CTL, RESET_DELAY, 18, 8) 25 FIELD(CTL, REGULATOR_ENABLE, 26, 1) 26 27 REG32(STAT, 4) 28 FIELD(STAT, DATA, 0, 10) 29 FIELD(STAT, VALID, 10, 1) 30 FIELD(STAT, INTERRUPT, 11, 1) 31 32 #define THERMAL_OFFSET_C 412 33 #define THERMAL_COEFF (-0.538f) 34 35 static uint16_t bcm2835_thermal_temp2adc(int temp_C) 36 { 37 return (temp_C - THERMAL_OFFSET_C) / THERMAL_COEFF; 38 } 39 40 static 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 60 static 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 80 static const MemoryRegionOps bcm2835_thermal_ops = { 81 .read = bcm2835_thermal_read, 82 .write = bcm2835_thermal_write, 83 .impl.min_access_size = 4, 84 .impl.max_access_size = 4, 85 .valid.min_access_size = 4, 86 .valid.max_access_size = 4, 87 .endianness = DEVICE_NATIVE_ENDIAN, 88 }; 89 90 static void bcm2835_thermal_reset(DeviceState *dev) 91 { 92 Bcm2835ThermalState *s = BCM2835_THERMAL(dev); 93 94 s->ctl = 0; 95 } 96 97 static void bcm2835_thermal_realize(DeviceState *dev, Error **errp) 98 { 99 Bcm2835ThermalState *s = BCM2835_THERMAL(dev); 100 101 memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_thermal_ops, 102 s, TYPE_BCM2835_THERMAL, 8); 103 sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem); 104 } 105 106 static const VMStateDescription bcm2835_thermal_vmstate = { 107 .name = "bcm2835_thermal", 108 .version_id = 1, 109 .minimum_version_id = 1, 110 .fields = (const VMStateField[]) { 111 VMSTATE_UINT32(ctl, Bcm2835ThermalState), 112 VMSTATE_END_OF_LIST() 113 } 114 }; 115 116 static void bcm2835_thermal_class_init(ObjectClass *klass, void *data) 117 { 118 DeviceClass *dc = DEVICE_CLASS(klass); 119 120 dc->realize = bcm2835_thermal_realize; 121 dc->reset = bcm2835_thermal_reset; 122 dc->vmsd = &bcm2835_thermal_vmstate; 123 } 124 125 static const TypeInfo bcm2835_thermal_info = { 126 .name = TYPE_BCM2835_THERMAL, 127 .parent = TYPE_SYS_BUS_DEVICE, 128 .instance_size = sizeof(Bcm2835ThermalState), 129 .class_init = bcm2835_thermal_class_init, 130 }; 131 132 static void bcm2835_thermal_register_types(void) 133 { 134 type_register_static(&bcm2835_thermal_info); 135 } 136 137 type_init(bcm2835_thermal_register_types) 138