evan
d613b079ef
Host tooling needs to know when the guest has actually sampled a button, since the firmware only polls the resistor ladder between e-ink refreshes.
107 lines
2.9 KiB
C
107 lines
2.9 KiB
C
/*
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* ESP32-C3 SAR ADC
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*
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* SPDX-License-Identifier: GPL-2.0-or-later
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*/
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#include "qemu/osdep.h"
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#include "qemu/module.h"
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#include "hw/adc/esp32c3_adc.h"
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#define ADC_ONETIME_SAMPLE 0x020
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#define ADC_DATA1 0x02c
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#define ADC_DATA2 0x030
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#define ADC_INT_RAW 0x044
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#define ADC_CHANNEL_SHIFT 25
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#define ADC_CHANNEL_MASK 0xf
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#define ADC_DONE (BIT(31) | BIT(30))
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#define ADC_MAX 0xfff
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static uint64_t esp32c3_adc_read(void *opaque, hwaddr addr, unsigned size)
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{
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ESP32C3AdcState *s = ESP32C3_ADC(opaque);
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if (addr == ADC_INT_RAW) {
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return ADC_DONE;
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}
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if (addr == ADC_DATA1 || addr == ADC_DATA2) {
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if (s->channel >= ESP32C3_ADC_CHANNELS) {
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return ADC_MAX;
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}
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qatomic_inc(&s->samples[s->channel]);
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return MIN(qatomic_read(&s->input[s->channel]), ADC_MAX);
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}
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return s->regs[addr / 4];
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}
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static void esp32c3_adc_write(void *opaque, hwaddr addr, uint64_t value,
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unsigned size)
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{
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ESP32C3AdcState *s = ESP32C3_ADC(opaque);
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s->regs[addr / 4] = value;
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if (addr == ADC_ONETIME_SAMPLE) {
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s->channel = (value >> ADC_CHANNEL_SHIFT) & ADC_CHANNEL_MASK;
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}
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}
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static const MemoryRegionOps esp32c3_adc_ops = {
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.read = esp32c3_adc_read,
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.write = esp32c3_adc_write,
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.endianness = DEVICE_LITTLE_ENDIAN,
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.valid = {
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.min_access_size = 4,
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.max_access_size = 4,
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},
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};
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static void esp32c3_adc_reset_hold(Object *obj, ResetType type)
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{
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ESP32C3AdcState *s = ESP32C3_ADC(obj);
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memset(s->regs, 0, sizeof(s->regs));
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for (int i = 0; i < ESP32C3_ADC_CHANNELS; i++) {
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s->input[i] = ADC_MAX;
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s->samples[i] = 0;
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}
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s->channel = 0;
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}
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static void esp32c3_adc_init(Object *obj)
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{
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ESP32C3AdcState *s = ESP32C3_ADC(obj);
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SysBusDevice *sbd = SYS_BUS_DEVICE(obj);
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memory_region_init_io(&s->iomem, obj, &esp32c3_adc_ops, s,
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TYPE_ESP32C3_ADC, ESP32C3_ADC_IO_SIZE);
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sysbus_init_mmio(sbd, &s->iomem);
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for (int i = 0; i < ESP32C3_ADC_CHANNELS; i++) {
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object_property_add_uint32_ptr(obj, "adci[*]", &s->input[i],
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OBJ_PROP_FLAG_READWRITE);
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object_property_add_uint32_ptr(obj, "adcsamples[*]", &s->samples[i],
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OBJ_PROP_FLAG_READ);
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}
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esp32c3_adc_reset_hold(obj, RESET_TYPE_COLD);
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}
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static void esp32c3_adc_class_init(ObjectClass *klass, void *data)
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{
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ResettableClass *rc = RESETTABLE_CLASS(klass);
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rc->phases.hold = esp32c3_adc_reset_hold;
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}
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static const TypeInfo esp32c3_adc_info = {
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.name = TYPE_ESP32C3_ADC,
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.parent = TYPE_SYS_BUS_DEVICE,
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.instance_size = sizeof(ESP32C3AdcState),
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.instance_init = esp32c3_adc_init,
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.class_init = esp32c3_adc_class_init,
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};
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static void esp32c3_adc_register_types(void)
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{
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type_register_static(&esp32c3_adc_info);
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}
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type_init(esp32c3_adc_register_types)
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