zephyr/drivers/adc/adc_ad559x.c

296 lines
7.6 KiB
C

/*
* Copyright (c) 2023 Grinn
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT adi_ad559x_adc
#include <zephyr/drivers/adc.h>
#include <zephyr/kernel.h>
#include <zephyr/sys/byteorder.h>
#include <zephyr/drivers/mfd/ad559x.h>
#define ADC_CONTEXT_USES_KERNEL_TIMER
#include "adc_context.h"
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(adc_ad559x, CONFIG_ADC_LOG_LEVEL);
#define AD559X_ADC_RD_POINTER_SIZE 1
#define AD559X_ADC_RD_POINTER 0x40
#define AD559X_ADC_RESOLUTION 12U
#define AD559X_ADC_VREF_MV 2500U
#define AD559X_ADC_RES_IND_BIT BIT(15)
#define AD559X_ADC_RES_CHAN_MASK GENMASK(14, 12)
#define AD559X_ADC_RES_VAL_MASK GENMASK(11, 0)
struct adc_ad559x_config {
const struct device *mfd_dev;
};
struct adc_ad559x_data {
struct adc_context ctx;
const struct device *dev;
uint8_t adc_conf;
uint16_t *buffer;
uint16_t *repeat_buffer;
uint8_t channels;
struct k_thread thread;
struct k_sem sem;
K_KERNEL_STACK_MEMBER(stack, CONFIG_ADC_AD559X_ACQUISITION_THREAD_STACK_SIZE);
};
static int adc_ad559x_channel_setup(const struct device *dev,
const struct adc_channel_cfg *channel_cfg)
{
const struct adc_ad559x_config *config = dev->config;
struct adc_ad559x_data *data = dev->data;
if (channel_cfg->channel_id >= AD559X_PIN_MAX) {
LOG_ERR("invalid channel id %d", channel_cfg->channel_id);
return -EINVAL;
}
data->adc_conf |= BIT(channel_cfg->channel_id);
return mfd_ad559x_write_reg(config->mfd_dev, AD559X_REG_ADC_CONFIG, data->adc_conf);
}
static int adc_ad559x_validate_buffer_size(const struct device *dev,
const struct adc_sequence *sequence)
{
uint8_t channels;
size_t needed;
channels = POPCOUNT(sequence->channels);
needed = channels * sizeof(uint16_t);
if (sequence->buffer_size < needed) {
return -ENOMEM;
}
return 0;
}
static int adc_ad559x_start_read(const struct device *dev, const struct adc_sequence *sequence)
{
struct adc_ad559x_data *data = dev->data;
int ret;
if (sequence->resolution != AD559X_ADC_RESOLUTION) {
LOG_ERR("invalid resolution %d", sequence->resolution);
return -EINVAL;
}
if (find_msb_set(sequence->channels) > AD559X_PIN_MAX) {
LOG_ERR("invalid channels in mask: 0x%08x", sequence->channels);
return -EINVAL;
}
ret = adc_ad559x_validate_buffer_size(dev, sequence);
if (ret < 0) {
LOG_ERR("insufficient buffer size");
return ret;
}
data->buffer = sequence->buffer;
adc_context_start_read(&data->ctx, sequence);
return adc_context_wait_for_completion(&data->ctx);
}
static int adc_ad559x_read_channel(const struct device *dev, uint8_t channel, uint16_t *result)
{
const struct adc_ad559x_config *config = dev->config;
uint16_t val;
uint8_t conv_channel;
int ret;
/* Select channel */
ret = mfd_ad559x_write_reg(config->mfd_dev, AD559X_REG_SEQ_ADC, BIT(channel));
if (ret < 0) {
return ret;
}
if (mfd_ad559x_has_pointer_byte_map(config->mfd_dev)) {
/* Start readback */
val = AD559X_ADC_RD_POINTER;
ret = mfd_ad559x_write_raw(config->mfd_dev, (uint8_t *)&val,
AD559X_ADC_RD_POINTER_SIZE);
if (ret < 0) {
return ret;
}
/* Read channel */
ret = mfd_ad559x_read_raw(config->mfd_dev, (uint8_t *)&val, sizeof(val));
if (ret < 0) {
return ret;
}
} else {
/*
* Invalid data:
* See Figure 46. Single-Channel ADC Conversion Sequence.
* The first conversion result always returns invalid data.
*/
(void)mfd_ad559x_read_raw(config->mfd_dev, (uint8_t *)&val, sizeof(val));
ret = mfd_ad559x_read_raw(config->mfd_dev, (uint8_t *)&val, sizeof(val));
if (ret < 0) {
return ret;
}
}
val = sys_be16_to_cpu(val);
/*
* Invalid data:
* See AD5592 "ADC section" in "Theory of operation" chapter.
* Valid ADC result has MSB bit set to 0.
*/
if ((val & AD559X_ADC_RES_IND_BIT) != 0) {
return -EAGAIN;
}
/*
* Invalid channel converted:
* See AD5592 "ADC section" in "Theory of operation" chapter.
* Conversion result contains channel number which should match requested channel.
*/
conv_channel = FIELD_GET(AD559X_ADC_RES_CHAN_MASK, val);
if (conv_channel != channel) {
return -EIO;
}
*result = val & AD559X_ADC_RES_VAL_MASK;
return 0;
}
static void adc_context_start_sampling(struct adc_context *ctx)
{
struct adc_ad559x_data *data = CONTAINER_OF(ctx, struct adc_ad559x_data, ctx);
data->channels = ctx->sequence.channels;
data->repeat_buffer = data->buffer;
k_sem_give(&data->sem);
}
static void adc_context_update_buffer_pointer(struct adc_context *ctx, bool repeat_sampling)
{
struct adc_ad559x_data *data = CONTAINER_OF(ctx, struct adc_ad559x_data, ctx);
if (repeat_sampling) {
data->buffer = data->repeat_buffer;
}
}
static void adc_ad559x_acquisition_thread(struct adc_ad559x_data *data)
{
uint16_t result;
uint8_t channel;
int ret;
while (true) {
k_sem_take(&data->sem, K_FOREVER);
while (data->channels != 0) {
channel = find_lsb_set(data->channels) - 1;
ret = adc_ad559x_read_channel(data->dev, channel, &result);
if (ret < 0) {
LOG_ERR("failed to read channel %d (ret %d)", channel, ret);
adc_context_complete(&data->ctx, ret);
break;
}
*data->buffer++ = result;
WRITE_BIT(data->channels, channel, 0);
}
adc_context_on_sampling_done(&data->ctx, data->dev);
}
}
static int adc_ad559x_read_async(const struct device *dev, const struct adc_sequence *sequence,
struct k_poll_signal *async)
{
struct adc_ad559x_data *data = dev->data;
int ret;
adc_context_lock(&data->ctx, async ? true : false, async);
ret = adc_ad559x_start_read(dev, sequence);
adc_context_release(&data->ctx, ret);
return ret;
}
static int adc_ad559x_read(const struct device *dev, const struct adc_sequence *sequence)
{
return adc_ad559x_read_async(dev, sequence, NULL);
}
static int adc_ad559x_init(const struct device *dev)
{
const struct adc_ad559x_config *config = dev->config;
struct adc_ad559x_data *data = dev->data;
k_tid_t tid;
int ret;
if (!device_is_ready(config->mfd_dev)) {
return -ENODEV;
}
ret = mfd_ad559x_write_reg(config->mfd_dev, AD559X_REG_PD_REF_CTRL, AD559X_EN_REF);
if (ret < 0) {
return ret;
}
data->dev = dev;
k_sem_init(&data->sem, 0, 1);
adc_context_init(&data->ctx);
tid = k_thread_create(&data->thread, data->stack,
K_KERNEL_STACK_SIZEOF(data->stack),
(k_thread_entry_t)adc_ad559x_acquisition_thread, data, NULL, NULL,
CONFIG_ADC_AD559X_ACQUISITION_THREAD_PRIO, 0, K_NO_WAIT);
if (IS_ENABLED(CONFIG_THREAD_NAME)) {
ret = k_thread_name_set(tid, "adc_ad559x");
if (ret < 0) {
return ret;
}
}
adc_context_unlock_unconditionally(&data->ctx);
return 0;
}
static const struct adc_driver_api adc_ad559x_api = {
.channel_setup = adc_ad559x_channel_setup,
.read = adc_ad559x_read,
#ifdef CONFIG_ADC_ASYNC
.read_async = adc_ad559x_read_async,
#endif
.ref_internal = AD559X_ADC_VREF_MV,
};
#define ADC_AD559X_DEFINE(inst) \
static const struct adc_ad559x_config adc_ad559x_config##inst = { \
.mfd_dev = DEVICE_DT_GET(DT_INST_PARENT(inst)), \
}; \
\
static struct adc_ad559x_data adc_ad559x_data##inst; \
\
DEVICE_DT_INST_DEFINE(inst, adc_ad559x_init, NULL, &adc_ad559x_data##inst, \
&adc_ad559x_config##inst, POST_KERNEL, CONFIG_MFD_INIT_PRIORITY, \
&adc_ad559x_api);
DT_INST_FOREACH_STATUS_OKAY(ADC_AD559X_DEFINE)