diff options
Diffstat (limited to 'hw/adc/npcm7xx_adc.c')
| -rw-r--r-- | hw/adc/npcm7xx_adc.c | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/hw/adc/npcm7xx_adc.c b/hw/adc/npcm7xx_adc.c new file mode 100644 index 000000000..0f0a9f63e --- /dev/null +++ b/hw/adc/npcm7xx_adc.c @@ -0,0 +1,301 @@ +/* + * Nuvoton NPCM7xx ADC Module + * + * Copyright 2020 Google LLC + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License as published by the + * Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * for more details. + */ + +#include "qemu/osdep.h" +#include "hw/adc/npcm7xx_adc.h" +#include "hw/qdev-clock.h" +#include "hw/qdev-properties.h" +#include "hw/registerfields.h" +#include "migration/vmstate.h" +#include "qemu/log.h" +#include "qemu/module.h" +#include "qemu/timer.h" +#include "qemu/units.h" +#include "trace.h" + +REG32(NPCM7XX_ADC_CON, 0x0) +REG32(NPCM7XX_ADC_DATA, 0x4) + +/* Register field definitions. */ +#define NPCM7XX_ADC_CON_MUX(rv) extract32(rv, 24, 4) +#define NPCM7XX_ADC_CON_INT_EN BIT(21) +#define NPCM7XX_ADC_CON_REFSEL BIT(19) +#define NPCM7XX_ADC_CON_INT BIT(18) +#define NPCM7XX_ADC_CON_EN BIT(17) +#define NPCM7XX_ADC_CON_RST BIT(16) +#define NPCM7XX_ADC_CON_CONV BIT(14) +#define NPCM7XX_ADC_CON_DIV(rv) extract32(rv, 1, 8) + +#define NPCM7XX_ADC_MAX_RESULT 1023 +#define NPCM7XX_ADC_DEFAULT_IREF 2000000 +#define NPCM7XX_ADC_CONV_CYCLES 20 +#define NPCM7XX_ADC_RESET_CYCLES 10 +#define NPCM7XX_ADC_R0_INPUT 500000 +#define NPCM7XX_ADC_R1_INPUT 1500000 + +static void npcm7xx_adc_reset(NPCM7xxADCState *s) +{ + timer_del(&s->conv_timer); + s->con = 0x000c0001; + s->data = 0x00000000; +} + +static uint32_t npcm7xx_adc_convert(uint32_t input, uint32_t ref) +{ + uint32_t result; + + result = input * (NPCM7XX_ADC_MAX_RESULT + 1) / ref; + if (result > NPCM7XX_ADC_MAX_RESULT) { + result = NPCM7XX_ADC_MAX_RESULT; + } + + return result; +} + +static uint32_t npcm7xx_adc_prescaler(NPCM7xxADCState *s) +{ + return 2 * (NPCM7XX_ADC_CON_DIV(s->con) + 1); +} + +static void npcm7xx_adc_start_timer(Clock *clk, QEMUTimer *timer, + uint32_t cycles, uint32_t prescaler) +{ + int64_t now = qemu_clock_get_ns(QEMU_CLOCK_VIRTUAL); + int64_t ticks = cycles; + int64_t ns; + + ticks *= prescaler; + ns = clock_ticks_to_ns(clk, ticks); + ns += now; + timer_mod(timer, ns); +} + +static void npcm7xx_adc_start_convert(NPCM7xxADCState *s) +{ + uint32_t prescaler = npcm7xx_adc_prescaler(s); + + npcm7xx_adc_start_timer(s->clock, &s->conv_timer, NPCM7XX_ADC_CONV_CYCLES, + prescaler); +} + +static void npcm7xx_adc_convert_done(void *opaque) +{ + NPCM7xxADCState *s = opaque; + uint32_t input = NPCM7XX_ADC_CON_MUX(s->con); + uint32_t ref = (s->con & NPCM7XX_ADC_CON_REFSEL) + ? s->iref : s->vref; + + if (input >= NPCM7XX_ADC_NUM_INPUTS) { + qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid input: %u\n", + __func__, input); + return; + } + s->data = npcm7xx_adc_convert(s->adci[input], ref); + if (s->con & NPCM7XX_ADC_CON_INT_EN) { + s->con |= NPCM7XX_ADC_CON_INT; + qemu_irq_raise(s->irq); + } + s->con &= ~NPCM7XX_ADC_CON_CONV; +} + +static void npcm7xx_adc_calibrate(NPCM7xxADCState *adc) +{ + adc->calibration_r_values[0] = npcm7xx_adc_convert(NPCM7XX_ADC_R0_INPUT, + adc->iref); + adc->calibration_r_values[1] = npcm7xx_adc_convert(NPCM7XX_ADC_R1_INPUT, + adc->iref); +} + +static void npcm7xx_adc_write_con(NPCM7xxADCState *s, uint32_t new_con) +{ + uint32_t old_con = s->con; + + /* Write ADC_INT to 1 to clear it */ + if (new_con & NPCM7XX_ADC_CON_INT) { + new_con &= ~NPCM7XX_ADC_CON_INT; + qemu_irq_lower(s->irq); + } else if (old_con & NPCM7XX_ADC_CON_INT) { + new_con |= NPCM7XX_ADC_CON_INT; + } + + s->con = new_con; + + if (s->con & NPCM7XX_ADC_CON_RST) { + npcm7xx_adc_reset(s); + return; + } + + if ((s->con & NPCM7XX_ADC_CON_EN)) { + if (s->con & NPCM7XX_ADC_CON_CONV) { + if (!(old_con & NPCM7XX_ADC_CON_CONV)) { + npcm7xx_adc_start_convert(s); + } + } else { + timer_del(&s->conv_timer); + } + } +} + +static uint64_t npcm7xx_adc_read(void *opaque, hwaddr offset, unsigned size) +{ + uint64_t value = 0; + NPCM7xxADCState *s = opaque; + + switch (offset) { + case A_NPCM7XX_ADC_CON: + value = s->con; + break; + + case A_NPCM7XX_ADC_DATA: + value = s->data; + break; + + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: invalid offset 0x%04" HWADDR_PRIx "\n", + __func__, offset); + break; + } + + trace_npcm7xx_adc_read(DEVICE(s)->canonical_path, offset, value); + return value; +} + +static void npcm7xx_adc_write(void *opaque, hwaddr offset, uint64_t v, + unsigned size) +{ + NPCM7xxADCState *s = opaque; + + trace_npcm7xx_adc_write(DEVICE(s)->canonical_path, offset, v); + switch (offset) { + case A_NPCM7XX_ADC_CON: + npcm7xx_adc_write_con(s, v); + break; + + case A_NPCM7XX_ADC_DATA: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: register @ 0x%04" HWADDR_PRIx " is read-only\n", + __func__, offset); + break; + + default: + qemu_log_mask(LOG_GUEST_ERROR, + "%s: invalid offset 0x%04" HWADDR_PRIx "\n", + __func__, offset); + break; + } + +} + +static const struct MemoryRegionOps npcm7xx_adc_ops = { + .read = npcm7xx_adc_read, + .write = npcm7xx_adc_write, + .endianness = DEVICE_LITTLE_ENDIAN, + .valid = { + .min_access_size = 4, + .max_access_size = 4, + .unaligned = false, + }, +}; + +static void npcm7xx_adc_enter_reset(Object *obj, ResetType type) +{ + NPCM7xxADCState *s = NPCM7XX_ADC(obj); + + npcm7xx_adc_reset(s); +} + +static void npcm7xx_adc_hold_reset(Object *obj) +{ + NPCM7xxADCState *s = NPCM7XX_ADC(obj); + + qemu_irq_lower(s->irq); +} + +static void npcm7xx_adc_init(Object *obj) +{ + NPCM7xxADCState *s = NPCM7XX_ADC(obj); + SysBusDevice *sbd = SYS_BUS_DEVICE(obj); + int i; + + sysbus_init_irq(sbd, &s->irq); + + timer_init_ns(&s->conv_timer, QEMU_CLOCK_VIRTUAL, + npcm7xx_adc_convert_done, s); + memory_region_init_io(&s->iomem, obj, &npcm7xx_adc_ops, s, + TYPE_NPCM7XX_ADC, 4 * KiB); + sysbus_init_mmio(sbd, &s->iomem); + s->clock = qdev_init_clock_in(DEVICE(s), "clock", NULL, NULL, 0); + + for (i = 0; i < NPCM7XX_ADC_NUM_INPUTS; ++i) { + object_property_add_uint32_ptr(obj, "adci[*]", + &s->adci[i], OBJ_PROP_FLAG_WRITE); + } + object_property_add_uint32_ptr(obj, "vref", + &s->vref, OBJ_PROP_FLAG_WRITE); + npcm7xx_adc_calibrate(s); +} + +static const VMStateDescription vmstate_npcm7xx_adc = { + .name = "npcm7xx-adc", + .version_id = 0, + .minimum_version_id = 0, + .fields = (VMStateField[]) { + VMSTATE_TIMER(conv_timer, NPCM7xxADCState), + VMSTATE_UINT32(con, NPCM7xxADCState), + VMSTATE_UINT32(data, NPCM7xxADCState), + VMSTATE_CLOCK(clock, NPCM7xxADCState), + VMSTATE_UINT32_ARRAY(adci, NPCM7xxADCState, NPCM7XX_ADC_NUM_INPUTS), + VMSTATE_UINT32(vref, NPCM7xxADCState), + VMSTATE_UINT32(iref, NPCM7xxADCState), + VMSTATE_UINT16_ARRAY(calibration_r_values, NPCM7xxADCState, + NPCM7XX_ADC_NUM_CALIB), + VMSTATE_END_OF_LIST(), + }, +}; + +static Property npcm7xx_timer_properties[] = { + DEFINE_PROP_UINT32("iref", NPCM7xxADCState, iref, NPCM7XX_ADC_DEFAULT_IREF), + DEFINE_PROP_END_OF_LIST(), +}; + +static void npcm7xx_adc_class_init(ObjectClass *klass, void *data) +{ + ResettableClass *rc = RESETTABLE_CLASS(klass); + DeviceClass *dc = DEVICE_CLASS(klass); + + dc->desc = "NPCM7xx ADC Module"; + dc->vmsd = &vmstate_npcm7xx_adc; + rc->phases.enter = npcm7xx_adc_enter_reset; + rc->phases.hold = npcm7xx_adc_hold_reset; + + device_class_set_props(dc, npcm7xx_timer_properties); +} + +static const TypeInfo npcm7xx_adc_info = { + .name = TYPE_NPCM7XX_ADC, + .parent = TYPE_SYS_BUS_DEVICE, + .instance_size = sizeof(NPCM7xxADCState), + .class_init = npcm7xx_adc_class_init, + .instance_init = npcm7xx_adc_init, +}; + +static void npcm7xx_adc_register_types(void) +{ + type_register_static(&npcm7xx_adc_info); +} + +type_init(npcm7xx_adc_register_types); |