blob: ec96e244bcdea2d25611656deb1d354b4450ffab [file] [log] [blame] [edit]
/*
* Copyright (c) 2018 Nordic Semiconductor ASA
*
* SPDX-License-Identifier: Apache-2.0
*/
#define ADC_CONTEXT_USES_KERNEL_TIMER
#include "adc_context.h"
#include <nrfx_adc.h>
#include <zephyr/dt-bindings/adc/nrf-adc.h>
#define LOG_LEVEL CONFIG_ADC_LOG_LEVEL
#include <zephyr/logging/log.h>
#include <zephyr/irq.h>
LOG_MODULE_REGISTER(adc_nrfx_adc);
#define DT_DRV_COMPAT nordic_nrf_adc
/* Ensure that definitions in nrf-adc.h match MDK. */
BUILD_ASSERT((NRF_ADC_AIN0 == NRF_ADC_CONFIG_INPUT_0) &&
(NRF_ADC_AIN1 == NRF_ADC_CONFIG_INPUT_1) &&
(NRF_ADC_AIN2 == NRF_ADC_CONFIG_INPUT_2) &&
(NRF_ADC_AIN3 == NRF_ADC_CONFIG_INPUT_3) &&
(NRF_ADC_AIN4 == NRF_ADC_CONFIG_INPUT_4) &&
(NRF_ADC_AIN5 == NRF_ADC_CONFIG_INPUT_5) &&
(NRF_ADC_AIN6 == NRF_ADC_CONFIG_INPUT_6) &&
(NRF_ADC_AIN7 == NRF_ADC_CONFIG_INPUT_7),
"Definitions from nrf-adc.h do not match those from nrf_adc.h");
struct driver_data {
struct adc_context ctx;
nrf_adc_value_t *buffer;
uint8_t active_channels;
};
static struct driver_data m_data = {
ADC_CONTEXT_INIT_TIMER(m_data, ctx),
ADC_CONTEXT_INIT_LOCK(m_data, ctx),
ADC_CONTEXT_INIT_SYNC(m_data, ctx),
};
static nrfx_adc_channel_t m_channels[CONFIG_ADC_NRFX_ADC_CHANNEL_COUNT];
/* Implementation of the ADC driver API function: adc_channel_setup. */
static int adc_nrfx_channel_setup(const struct device *dev,
const struct adc_channel_cfg *channel_cfg)
{
uint8_t channel_id = channel_cfg->channel_id;
nrf_adc_config_t *config = &m_channels[channel_id].config;
if (channel_id >= CONFIG_ADC_NRFX_ADC_CHANNEL_COUNT) {
return -EINVAL;
}
if (channel_cfg->acquisition_time != ADC_ACQ_TIME_DEFAULT) {
LOG_ERR("Selected ADC acquisition time is not valid");
return -EINVAL;
}
if (channel_cfg->differential) {
LOG_ERR("Differential channels are not supported");
return -EINVAL;
}
switch (channel_cfg->gain) {
case ADC_GAIN_1_3:
config->scaling = NRF_ADC_CONFIG_SCALING_INPUT_ONE_THIRD;
break;
case ADC_GAIN_2_3:
config->scaling = NRF_ADC_CONFIG_SCALING_INPUT_TWO_THIRDS;
break;
case ADC_GAIN_1:
config->scaling = NRF_ADC_CONFIG_SCALING_INPUT_FULL_SCALE;
break;
default:
LOG_ERR("Selected ADC gain is not valid");
return -EINVAL;
}
switch (channel_cfg->reference) {
case ADC_REF_INTERNAL:
config->reference = NRF_ADC_CONFIG_REF_VBG;
config->extref = NRF_ADC_CONFIG_EXTREFSEL_NONE;
break;
case ADC_REF_VDD_1_2:
config->reference = NRF_ADC_CONFIG_REF_SUPPLY_ONE_HALF;
config->extref = NRF_ADC_CONFIG_EXTREFSEL_NONE;
break;
case ADC_REF_VDD_1_3:
config->reference = NRF_ADC_CONFIG_REF_SUPPLY_ONE_THIRD;
config->extref = NRF_ADC_CONFIG_EXTREFSEL_NONE;
break;
case ADC_REF_EXTERNAL0:
config->reference = NRF_ADC_CONFIG_REF_EXT;
config->extref = NRF_ADC_CONFIG_EXTREFSEL_AREF0;
break;
case ADC_REF_EXTERNAL1:
config->reference = NRF_ADC_CONFIG_REF_EXT;
config->extref = NRF_ADC_CONFIG_EXTREFSEL_AREF1;
break;
default:
LOG_ERR("Selected ADC reference is not valid");
return -EINVAL;
}
config->input = channel_cfg->input_positive;
config->resolution = NRF_ADC_CONFIG_RES_8BIT;
return 0;
}
static void adc_context_start_sampling(struct adc_context *ctx)
{
ARG_UNUSED(ctx);
nrfx_adc_buffer_convert(m_data.buffer, m_data.active_channels);
nrfx_adc_sample();
}
static void adc_context_update_buffer_pointer(struct adc_context *ctx,
bool repeat)
{
ARG_UNUSED(ctx);
if (!repeat) {
m_data.buffer += m_data.active_channels;
}
}
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(nrf_adc_value_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 start_read(const struct device *dev,
const struct adc_sequence *sequence)
{
int error;
uint32_t selected_channels = sequence->channels;
uint8_t active_channels;
uint8_t channel_id;
nrf_adc_config_resolution_t nrf_resolution;
/* Signal an error if channel selection is invalid (no channels or
* a non-existing one is selected).
*/
if (!selected_channels ||
(selected_channels &
~BIT_MASK(CONFIG_ADC_NRFX_ADC_CHANNEL_COUNT))) {
LOG_ERR("Invalid selection of channels");
return -EINVAL;
}
if (sequence->oversampling != 0U) {
LOG_ERR("Oversampling is not supported");
return -EINVAL;
}
switch (sequence->resolution) {
case 8:
nrf_resolution = NRF_ADC_CONFIG_RES_8BIT;
break;
case 9:
nrf_resolution = NRF_ADC_CONFIG_RES_9BIT;
break;
case 10:
nrf_resolution = NRF_ADC_CONFIG_RES_10BIT;
break;
default:
LOG_ERR("ADC resolution value %d is not valid",
sequence->resolution);
return -EINVAL;
}
active_channels = 0U;
nrfx_adc_all_channels_disable();
/* Enable the channels selected for the pointed sequence.
*/
channel_id = 0U;
while (selected_channels) {
if (selected_channels & BIT(0)) {
/* The nrfx driver requires setting the resolution
* for each enabled channel individually.
*/
m_channels[channel_id].config.resolution =
nrf_resolution;
nrfx_adc_channel_enable(&m_channels[channel_id]);
++active_channels;
}
selected_channels >>= 1;
++channel_id;
}
error = check_buffer_size(sequence, active_channels);
if (error) {
return error;
}
m_data.buffer = sequence->buffer;
m_data.active_channels = active_channels;
adc_context_start_read(&m_data.ctx, sequence);
error = adc_context_wait_for_completion(&m_data.ctx);
return error;
}
/* Implementation of the ADC driver API function: adc_read. */
static int adc_nrfx_read(const struct device *dev,
const struct adc_sequence *sequence)
{
int error;
adc_context_lock(&m_data.ctx, false, NULL);
error = start_read(dev, sequence);
adc_context_release(&m_data.ctx, error);
return error;
}
#ifdef CONFIG_ADC_ASYNC
/* Implementation of the ADC driver API function: adc_read_sync. */
static int adc_nrfx_read_async(const struct device *dev,
const struct adc_sequence *sequence,
struct k_poll_signal *async)
{
int error;
adc_context_lock(&m_data.ctx, true, async);
error = start_read(dev, sequence);
adc_context_release(&m_data.ctx, error);
return error;
}
#endif /* CONFIG_ADC_ASYNC */
static void event_handler(const nrfx_adc_evt_t *p_event)
{
const struct device *const dev = DEVICE_DT_INST_GET(0);
if (p_event->type == NRFX_ADC_EVT_DONE) {
adc_context_on_sampling_done(&m_data.ctx, dev);
}
}
static int init_adc(const struct device *dev)
{
const nrfx_adc_config_t config = NRFX_ADC_DEFAULT_CONFIG;
nrfx_err_t result = nrfx_adc_init(&config, event_handler);
if (result != NRFX_SUCCESS) {
LOG_ERR("Failed to initialize device: %s",
dev->name);
return -EBUSY;
}
IRQ_CONNECT(DT_INST_IRQN(0), DT_INST_IRQ(0, priority),
nrfx_isr, nrfx_adc_irq_handler, 0);
adc_context_unlock_unconditionally(&m_data.ctx);
return 0;
}
static const struct adc_driver_api adc_nrfx_driver_api = {
.channel_setup = adc_nrfx_channel_setup,
.read = adc_nrfx_read,
#ifdef CONFIG_ADC_ASYNC
.read_async = adc_nrfx_read_async,
#endif
.ref_internal = 1200,
};
/*
* There is only one instance on supported SoCs, so inst is guaranteed
* to be 0 if any instance is okay. (We use adc_0 above, so the driver
* is relying on the numeric instance value in a way that happens to
* be safe.)
*
* Just in case that assumption becomes invalid in the future, we use
* a BUILD_ASSERT().
*/
#define ADC_INIT(inst) \
BUILD_ASSERT((inst) == 0, \
"multiple instances not supported"); \
DEVICE_DT_INST_DEFINE(0, \
init_adc, NULL, NULL, NULL, \
POST_KERNEL, \
CONFIG_ADC_INIT_PRIORITY, \
&adc_nrfx_driver_api);
DT_INST_FOREACH_STATUS_OKAY(ADC_INIT)