blob: 2aa35cb43b1b728a0dc107397a6e6108f26b2188 [file] [log] [blame]
/*
* Copyright (c) 2021 ITE Corporation. All Rights Reserved.
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT ite_it8xxx2_adc
#define LOG_LEVEL CONFIG_ADC_LOG_LEVEL
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(adc_ite_it8xxx2);
#include <zephyr/drivers/adc.h>
#include <zephyr/drivers/pinctrl.h>
#include <soc.h>
#include <soc_dt.h>
#include <errno.h>
#include <assert.h>
#include <zephyr/irq.h>
#define ADC_CONTEXT_USES_KERNEL_TIMER
#include "adc_context.h"
/* ADC internal reference voltage (Unit:mV) */
#define IT8XXX2_ADC_VREF_VOL 3000
/* ADC channels disabled */
#define IT8XXX2_ADC_CHANNEL_DISABLED 0x1F
/* ADC sample time delay (Unit:us) */
#define IT8XXX2_ADC_SAMPLE_TIME_US 200
/* Wait next clock rising (Clock source 32.768K) */
#define IT8XXX2_WAIT_NEXT_CLOCK_TIME_US 31
/* ADC channels offset */
#define ADC_CHANNEL_SHIFT 5
#define ADC_CHANNEL_OFFSET(ch) ((ch)-CHIP_ADC_CH13-ADC_CHANNEL_SHIFT)
/* List of ADC channels. */
enum chip_adc_channel {
CHIP_ADC_CH0 = 0,
CHIP_ADC_CH1,
CHIP_ADC_CH2,
CHIP_ADC_CH3,
CHIP_ADC_CH4,
CHIP_ADC_CH5,
CHIP_ADC_CH6,
CHIP_ADC_CH7,
CHIP_ADC_CH13,
CHIP_ADC_CH14,
CHIP_ADC_CH15,
CHIP_ADC_CH16,
CHIP_ADC_COUNT,
};
struct adc_it8xxx2_data {
struct adc_context ctx;
struct k_sem sem;
/* Channel ID */
uint32_t ch;
/* Save ADC result to the buffer. */
uint16_t *buffer;
/*
* The sample buffer pointer should be prepared
* for writing of next sampling results.
*/
uint16_t *repeat_buffer;
};
/*
* Structure adc_it8xxx2_cfg is about the setting of adc
* this config will be used at initial time
*/
struct adc_it8xxx2_cfg {
/* ADC alternate configuration */
const struct pinctrl_dev_config *pcfg;
};
#define ADC_IT8XXX2_REG_BASE \
((struct adc_it8xxx2_regs *)(DT_INST_REG_ADDR(0)))
static int adc_it8xxx2_channel_setup(const struct device *dev,
const struct adc_channel_cfg *channel_cfg)
{
uint8_t channel_id = channel_cfg->channel_id;
if (channel_cfg->acquisition_time != ADC_ACQ_TIME_DEFAULT) {
LOG_ERR("Selected ADC acquisition time is not valid");
return -EINVAL;
}
/* Support channels 0~7 and 13~16 */
if (!((channel_id >= 0 && channel_id <= 7) ||
(channel_id >= 13 && channel_id <= 16))) {
LOG_ERR("Channel %d is not valid", channel_id);
return -EINVAL;
}
/* Channels 13~16 should be shifted by 5 */
if (channel_id > CHIP_ADC_CH7) {
channel_id -= ADC_CHANNEL_SHIFT;
}
if (channel_cfg->gain != ADC_GAIN_1) {
LOG_ERR("Invalid channel gain");
return -EINVAL;
}
if (channel_cfg->reference != ADC_REF_INTERNAL) {
LOG_ERR("Invalid channel reference");
return -EINVAL;
}
LOG_DBG("Channel setup succeeded!");
return 0;
}
static void adc_disable_measurement(uint32_t ch)
{
struct adc_it8xxx2_regs *const adc_regs = ADC_IT8XXX2_REG_BASE;
if (ch <= CHIP_ADC_CH7) {
/*
* Disable measurement.
* bit(4:0) = 0x1f : channel disable
*/
adc_regs->VCH0CTL = IT8XXX2_ADC_DATVAL |
IT8XXX2_ADC_CHANNEL_DISABLED;
} else {
/*
* Channels 13~16 controller setting.
* bit7 = 1: End of conversion. New data is available in
* VCHDATL/VCHDATM.
*/
adc_regs->adc_vchs_ctrl[ADC_CHANNEL_OFFSET(ch)].VCHCTL =
IT8XXX2_ADC_DATVAL;
}
/* ADC module disable */
adc_regs->ADCCFG &= ~IT8XXX2_ADC_ADCEN;
/* disable adc interrupt */
irq_disable(DT_INST_IRQN(0));
}
static int adc_data_valid(const struct device *dev)
{
struct adc_it8xxx2_regs *const adc_regs = ADC_IT8XXX2_REG_BASE;
struct adc_it8xxx2_data *data = dev->data;
return (data->ch <= CHIP_ADC_CH7) ?
(adc_regs->VCH0CTL & IT8XXX2_ADC_DATVAL) :
(adc_regs->ADCDVSTS2 & BIT(ADC_CHANNEL_OFFSET(data->ch)));
}
/* Get result for each ADC selected channel. */
static void adc_it8xxx2_get_sample(const struct device *dev)
{
struct adc_it8xxx2_data *data = dev->data;
struct adc_it8xxx2_regs *const adc_regs = ADC_IT8XXX2_REG_BASE;
if (adc_data_valid(dev)) {
if (data->ch <= CHIP_ADC_CH7) {
/* Read adc raw data of msb and lsb */
*data->buffer++ = adc_regs->VCH0DATM << 8 |
adc_regs->VCH0DATL;
} else {
/* Read adc channels 13~16 raw data of msb and lsb */
*data->buffer++ =
adc_regs->adc_vchs_ctrl[ADC_CHANNEL_OFFSET(data->ch)].VCHDATM << 8 |
adc_regs->adc_vchs_ctrl[ADC_CHANNEL_OFFSET(data->ch)].VCHDATL;
}
} else {
LOG_WRN("ADC failed to read (regs=%x, ch=%d)",
adc_regs->ADCDVSTS, data->ch);
}
adc_disable_measurement(data->ch);
}
static void adc_poll_valid_data(void)
{
const struct device *const dev = DEVICE_DT_INST_GET(0);
int valid = 0;
/*
* If the polling waits for a valid data longer than
* the sampling time limit, the program will return.
*/
for (int i = 0U; i < (IT8XXX2_ADC_SAMPLE_TIME_US /
IT8XXX2_WAIT_NEXT_CLOCK_TIME_US); i++) {
/* Wait next clock time (1/32.768K~=30.5us) */
k_busy_wait(IT8XXX2_WAIT_NEXT_CLOCK_TIME_US);
if (adc_data_valid(dev)) {
valid = 1;
break;
}
}
if (valid) {
adc_it8xxx2_get_sample(dev);
} else {
LOG_ERR("Sampling timeout.");
return;
}
}
static void adc_enable_measurement(uint32_t ch)
{
struct adc_it8xxx2_regs *const adc_regs = ADC_IT8XXX2_REG_BASE;
const struct device *const dev = DEVICE_DT_INST_GET(0);
struct adc_it8xxx2_data *data = dev->data;
if (ch <= CHIP_ADC_CH7) {
/* Select and enable a voltage channel input for measurement */
adc_regs->VCH0CTL = (IT8XXX2_ADC_DATVAL | IT8XXX2_ADC_INTDVEN) + ch;
} else {
/* Channels 13~16 controller setting */
adc_regs->adc_vchs_ctrl[ADC_CHANNEL_OFFSET(ch)].VCHCTL =
IT8XXX2_ADC_DATVAL | IT8XXX2_ADC_INTDVEN | IT8XXX2_ADC_VCHEN;
}
/* ADC module enable */
adc_regs->ADCCFG |= IT8XXX2_ADC_ADCEN;
/*
* In the sampling process, it is possible to read multiple channels
* at a time. The ADC sampling of it8xxx2 needs to read each channel
* in sequence, so it needs to wait for an interrupt to read data in
* the loop through k_sem_take(). But k_timer_start() is used in the
* interval test in test_adc.c, so we need to use polling wait instead
* of k_sem_take() to wait, otherwise it will cause kernel panic.
*
* k_is_in_isr() can determine whether to use polling or k_sem_take()
* at present.
*/
if (k_is_in_isr()) {
/* polling wait for a valid data */
adc_poll_valid_data();
} else {
/* Enable adc interrupt */
irq_enable(DT_INST_IRQN(0));
/* Wait for an interrupt to read valid data. */
k_sem_take(&data->sem, K_FOREVER);
}
}
static int check_buffer_size(const struct adc_sequence *sequence,
uint8_t active_channels)
{
size_t needed_buffer_size;
needed_buffer_size = active_channels * sizeof(uint16_t);
if (sequence->options) {
needed_buffer_size *= (1 + sequence->options->extra_samplings);
}
if (sequence->buffer_size < needed_buffer_size) {
LOG_ERR("Provided buffer is too small (%u/%u)",
sequence->buffer_size, needed_buffer_size);
return -ENOMEM;
}
return 0;
}
static int adc_it8xxx2_start_read(const struct device *dev,
const struct adc_sequence *sequence)
{
struct adc_it8xxx2_data *data = dev->data;
uint32_t channel_mask = sequence->channels;
/* Channels 13~16 should be shifted to the right by 5 */
if (channel_mask > BIT(CHIP_ADC_CH7)) {
channel_mask >>= ADC_CHANNEL_SHIFT;
}
if (!channel_mask || channel_mask & ~BIT_MASK(CHIP_ADC_COUNT)) {
LOG_ERR("Invalid selection of channels");
return -EINVAL;
}
if (!sequence->resolution) {
LOG_ERR("ADC resolution is not valid");
return -EINVAL;
}
LOG_DBG("Configure resolution=%d", sequence->resolution);
data->buffer = sequence->buffer;
adc_context_start_read(&data->ctx, sequence);
return adc_context_wait_for_completion(&data->ctx);
}
static void adc_context_start_sampling(struct adc_context *ctx)
{
struct adc_it8xxx2_data *data =
CONTAINER_OF(ctx, struct adc_it8xxx2_data, ctx);
uint32_t channels = ctx->sequence.channels;
uint8_t channel_count = 0;
data->repeat_buffer = data->buffer;
/*
* The ADC sampling of it8xxx2 needs to read each channel
* in sequence.
*/
while (channels) {
data->ch = find_lsb_set(channels) - 1;
channels &= ~BIT(data->ch);
adc_enable_measurement(data->ch);
channel_count++;
}
if (check_buffer_size(&ctx->sequence, channel_count)) {
return;
}
adc_context_on_sampling_done(&data->ctx, DEVICE_DT_INST_GET(0));
}
static int adc_it8xxx2_read(const struct device *dev,
const struct adc_sequence *sequence)
{
struct adc_it8xxx2_data *data = dev->data;
int err;
adc_context_lock(&data->ctx, false, NULL);
err = adc_it8xxx2_start_read(dev, sequence);
adc_context_release(&data->ctx, err);
return err;
}
#ifdef CONFIG_ADC_ASYNC
static int adc_it8xxx2_read_async(const struct device *dev,
const struct adc_sequence *sequence,
struct k_poll_signal *async)
{
struct adc_it8xxx2_data *data = dev->data;
int err;
adc_context_lock(&data->ctx, true, async);
err = adc_it8xxx2_start_read(dev, sequence);
adc_context_release(&data->ctx, err);
return err;
}
#endif /* CONFIG_ADC_ASYNC */
static void adc_context_update_buffer_pointer(struct adc_context *ctx,
bool repeat_sampling)
{
struct adc_it8xxx2_data *data =
CONTAINER_OF(ctx, struct adc_it8xxx2_data, ctx);
if (repeat_sampling) {
data->buffer = data->repeat_buffer;
}
}
static void adc_it8xxx2_isr(const struct device *dev)
{
struct adc_it8xxx2_data *data = dev->data;
LOG_DBG("ADC ISR triggered.");
adc_it8xxx2_get_sample(dev);
k_sem_give(&data->sem);
}
static const struct adc_driver_api api_it8xxx2_driver_api = {
.channel_setup = adc_it8xxx2_channel_setup,
.read = adc_it8xxx2_read,
#ifdef CONFIG_ADC_ASYNC
.read_async = adc_it8xxx2_read_async,
#endif
.ref_internal = IT8XXX2_ADC_VREF_VOL,
};
/*
* ADC analog accuracy initialization (only once after VSTBY power on)
*
* Write 1 to this bit and write 0 to this bit immediately once and
* only once during the firmware initialization and do not write 1 again
* after initialization since IT83xx takes much power consumption
* if this bit is set as 1
*/
static void adc_accuracy_initialization(void)
{
struct adc_it8xxx2_regs *const adc_regs = ADC_IT8XXX2_REG_BASE;
/* Start adc accuracy initialization */
adc_regs->ADCSTS |= IT8XXX2_ADC_AINITB;
/* Enable automatic HW calibration. */
adc_regs->KDCTL |= IT8XXX2_ADC_AHCE;
/* Stop adc accuracy initialization */
adc_regs->ADCSTS &= ~IT8XXX2_ADC_AINITB;
}
static int adc_it8xxx2_init(const struct device *dev)
{
const struct adc_it8xxx2_cfg *config = dev->config;
struct adc_it8xxx2_data *data = dev->data;
struct adc_it8xxx2_regs *const adc_regs = ADC_IT8XXX2_REG_BASE;
int status;
/* ADC analog accuracy initialization */
adc_accuracy_initialization();
/* Set the pin to ADC alternate function. */
status = pinctrl_apply_state(config->pcfg, PINCTRL_STATE_DEFAULT);
if (status < 0) {
LOG_ERR("Failed to configure ADC pins");
return status;
}
/*
* The ADC channel conversion time is 30.8*(SCLKDIV+1) us.
* (Current setting is 61.6us)
*
* NOTE: A sample time delay (60us) also need to be included in
* conversion time, so the final result is ~= 121.6us.
*/
adc_regs->ADCSTS &= ~IT8XXX2_ADC_ADCCTS1;
adc_regs->ADCCFG &= ~IT8XXX2_ADC_ADCCTS0;
/*
* bit[5-0]@ADCCTL : SCLKDIV
* SCLKDIV has to be equal to or greater than 1h;
*/
adc_regs->ADCCTL = 1;
/*
* Enable this bit, and data of VCHxDATL/VCHxDATM will be
* kept until data valid is cleared.
*/
adc_regs->ADCGCR |= IT8XXX2_ADC_DBKEN;
IRQ_CONNECT(DT_INST_IRQN(0), DT_INST_IRQ(0, priority),
adc_it8xxx2_isr, DEVICE_DT_INST_GET(0), 0);
k_sem_init(&data->sem, 0, 1);
adc_context_unlock_unconditionally(&data->ctx);
return 0;
}
static struct adc_it8xxx2_data adc_it8xxx2_data_0 = {
ADC_CONTEXT_INIT_TIMER(adc_it8xxx2_data_0, ctx),
ADC_CONTEXT_INIT_LOCK(adc_it8xxx2_data_0, ctx),
ADC_CONTEXT_INIT_SYNC(adc_it8xxx2_data_0, ctx),
};
PINCTRL_DT_INST_DEFINE(0);
static const struct adc_it8xxx2_cfg adc_it8xxx2_cfg_0 = {
.pcfg = PINCTRL_DT_INST_DEV_CONFIG_GET(0),
};
DEVICE_DT_INST_DEFINE(0, adc_it8xxx2_init,
NULL,
&adc_it8xxx2_data_0,
&adc_it8xxx2_cfg_0, PRE_KERNEL_1,
CONFIG_ADC_INIT_PRIORITY,
&api_it8xxx2_driver_api);