diff options
Diffstat (limited to 'hw/misc/bcm2835_thermal.c')
| -rw-r--r-- | hw/misc/bcm2835_thermal.c | 135 |
1 files changed, 135 insertions, 0 deletions
diff --git a/hw/misc/bcm2835_thermal.c b/hw/misc/bcm2835_thermal.c new file mode 100644 index 0000000000..c6f3b1ad60 --- /dev/null +++ b/hw/misc/bcm2835_thermal.c @@ -0,0 +1,135 @@ +/* + * BCM2835 dummy thermal sensor + * + * Copyright (C) 2019 Philippe Mathieu-Daudé <f4bug@amsat.org> + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "qemu/log.h" +#include "qapi/error.h" +#include "hw/misc/bcm2835_thermal.h" +#include "hw/registerfields.h" +#include "migration/vmstate.h" + +REG32(CTL, 0) +FIELD(CTL, POWER_DOWN, 0, 1) +FIELD(CTL, RESET, 1, 1) +FIELD(CTL, BANDGAP_CTRL, 2, 3) +FIELD(CTL, INTERRUPT_ENABLE, 5, 1) +FIELD(CTL, DIRECT, 6, 1) +FIELD(CTL, INTERRUPT_CLEAR, 7, 1) +FIELD(CTL, HOLD, 8, 10) +FIELD(CTL, RESET_DELAY, 18, 8) +FIELD(CTL, REGULATOR_ENABLE, 26, 1) + +REG32(STAT, 4) +FIELD(STAT, DATA, 0, 10) +FIELD(STAT, VALID, 10, 1) +FIELD(STAT, INTERRUPT, 11, 1) + +#define THERMAL_OFFSET_C 412 +#define THERMAL_COEFF (-0.538f) + +static uint16_t bcm2835_thermal_temp2adc(int temp_C) +{ + return (temp_C - THERMAL_OFFSET_C) / THERMAL_COEFF; +} + +static uint64_t bcm2835_thermal_read(void *opaque, hwaddr addr, unsigned size) +{ + Bcm2835ThermalState *s = BCM2835_THERMAL(opaque); + uint32_t val = 0; + + switch (addr) { + case A_CTL: + val = s->ctl; + break; + case A_STAT: + /* Temperature is constantly 25°C. */ + val = FIELD_DP32(bcm2835_thermal_temp2adc(25), STAT, VALID, true); + break; + default: + /* MemoryRegionOps are aligned, so this can not happen. */ + g_assert_not_reached(); + } + return val; +} + +static void bcm2835_thermal_write(void *opaque, hwaddr addr, + uint64_t value, unsigned size) +{ + Bcm2835ThermalState *s = BCM2835_THERMAL(opaque); + + switch (addr) { + case A_CTL: + s->ctl = value; + break; + case A_STAT: + qemu_log_mask(LOG_GUEST_ERROR, "%s: write 0x%" PRIx64 + " to 0x%" HWADDR_PRIx "\n", + __func__, value, addr); + break; + default: + /* MemoryRegionOps are aligned, so this can not happen. */ + g_assert_not_reached(); + } +} + +static const MemoryRegionOps bcm2835_thermal_ops = { + .read = bcm2835_thermal_read, + .write = bcm2835_thermal_write, + .impl.max_access_size = 4, + .valid.min_access_size = 4, + .endianness = DEVICE_NATIVE_ENDIAN, +}; + +static void bcm2835_thermal_reset(DeviceState *dev) +{ + Bcm2835ThermalState *s = BCM2835_THERMAL(dev); + + s->ctl = 0; +} + +static void bcm2835_thermal_realize(DeviceState *dev, Error **errp) +{ + Bcm2835ThermalState *s = BCM2835_THERMAL(dev); + + memory_region_init_io(&s->iomem, OBJECT(s), &bcm2835_thermal_ops, + s, TYPE_BCM2835_THERMAL, 8); + sysbus_init_mmio(SYS_BUS_DEVICE(s), &s->iomem); +} + +static const VMStateDescription bcm2835_thermal_vmstate = { + .name = "bcm2835_thermal", + .version_id = 1, + .minimum_version_id = 1, + .fields = (VMStateField[]) { + VMSTATE_UINT32(ctl, Bcm2835ThermalState), + VMSTATE_END_OF_LIST() + } +}; + +static void bcm2835_thermal_class_init(ObjectClass *klass, void *data) +{ + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->realize = bcm2835_thermal_realize; + dc->reset = bcm2835_thermal_reset; + dc->vmsd = &bcm2835_thermal_vmstate; +} + +static const TypeInfo bcm2835_thermal_info = { + .name = TYPE_BCM2835_THERMAL, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(Bcm2835ThermalState), + .class_init = bcm2835_thermal_class_init, +}; + +static void bcm2835_thermal_register_types(void) +{ + type_register_static(&bcm2835_thermal_info); +} + +type_init(bcm2835_thermal_register_types) |