hw/adc/npcm7xx_adc.c - qemu - Git at Google

 /*
  * 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(13)
 #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_READWRITE);
     }
     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 = (const 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);
	/*
	* 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(13)
	#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_READWRITE);
	}
	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 = (const 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);