zephyr/drivers/adc/adc_tla2021.c

319 lines
8.1 KiB
C

/*
* Copyright (c) 2023 Caspar Friedrich <c.s.w.friedrich@gmail.com>
*
* SPDX-License-Identifier: Apache-2.0
*/
#include <stdint.h>
#include <zephyr/devicetree.h>
#include <zephyr/drivers/adc.h>
#include <zephyr/drivers/i2c.h>
#include <zephyr/kernel.h>
#include <zephyr/logging/log.h>
#include <zephyr/sys/byteorder.h>
#define ADC_CONTEXT_USES_KERNEL_TIMER
/*
* This requires to be included _after_ `#define ADC_CONTEXT_USES_KERNEL_TIMER`
*/
#include "adc_context.h"
#define DT_DRV_COMPAT ti_tla2021
LOG_MODULE_REGISTER(tla2021, CONFIG_ADC_LOG_LEVEL);
#define ACQ_THREAD_PRIORITY CONFIG_ADC_TLA2021_ACQUISITION_THREAD_PRIORITY
#define ACQ_THREAD_STACK_SIZE CONFIG_ADC_TLA2021_ACQUISITION_THREAD_STACK_SIZE
#define ADC_CHANNEL_msk BIT(0)
#define ADC_RESOLUTION 12
/*
* Conversion Data Register (RP = 00h) [reset = 0000h]
*/
#define REG_DATA 0x00
#define REG_DATA_pos 4
/*
* Configuration Register (RP = 01h) [reset = 8583h]
*/
#define REG_CONFIG 0x01
#define REG_CONFIG_DEFAULT 0x8583
#define REG_CONFIG_DR_pos 5
#define REG_CONFIG_MODE_pos 8
#define REG_CONFIG_PGA_pos 9 /* TLA2022 and TLA2024 Only */
#define REG_CONFIG_MUX_pos 12 /* TLA2024 Only */
#define REG_CONFIG_OS_pos 15
#define REG_CONFIG_OS_msk (BIT_MASK(1) << REG_CONFIG_OS_pos)
typedef int16_t tla2021_reg_data_t;
typedef uint16_t tla2021_reg_config_t;
struct tla2021_config {
const struct i2c_dt_spec bus;
k_tid_t acq_thread_id;
};
struct tla2021_data {
const struct device *dev;
struct adc_context ctx;
struct k_sem acq_lock;
tla2021_reg_data_t *buffer;
tla2021_reg_data_t *repeat_buffer;
/*
* Shadow register
*/
tla2021_reg_config_t reg_config;
};
static int tla2021_read_register(const struct device *dev, uint8_t reg, uint16_t *value)
{
int ret;
const struct tla2021_config *config = dev->config;
uint8_t tmp[2];
ret = i2c_write_read_dt(&config->bus, &reg, sizeof(reg), tmp, sizeof(tmp));
if (ret) {
return ret;
}
*value = sys_get_be16(tmp);
return 0;
}
static int tla2021_write_register(const struct device *dev, uint8_t reg, uint16_t value)
{
int ret;
const struct tla2021_config *config = dev->config;
uint8_t tmp[3] = {reg};
sys_put_be16(value, &tmp[1]);
ret = i2c_write_dt(&config->bus, tmp, sizeof(tmp));
if (ret) {
return ret;
}
return 0;
}
static int tla2021_channel_setup(const struct device *dev, const struct adc_channel_cfg *cfg)
{
if (cfg->gain != ADC_GAIN_1) {
LOG_ERR("Invalid gain");
return -EINVAL;
}
if (cfg->reference != ADC_REF_INTERNAL) {
LOG_ERR("Invalid reference");
return -EINVAL;
}
if (cfg->acquisition_time != ADC_ACQ_TIME_DEFAULT) {
LOG_ERR("Invalid acquisition time");
return -EINVAL;
}
return 0;
}
static int tla2021_start_read(const struct device *dev, const struct adc_sequence *seq)
{
struct tla2021_data *data = dev->data;
const size_t num_extra_samples = seq->options ? seq->options->extra_samplings : 0;
const size_t num_samples = (1 + num_extra_samples) * POPCOUNT(seq->channels);
if (!(seq->channels & ADC_CHANNEL_msk)) {
LOG_ERR("Selected channel(s) not supported: %x", seq->channels);
return -EINVAL;
}
if (seq->resolution != ADC_RESOLUTION) {
LOG_ERR("Selected resolution not supported: %d", seq->resolution);
return -EINVAL;
}
if (seq->oversampling) {
LOG_ERR("Oversampling is not supported");
return -EINVAL;
}
if (seq->calibrate) {
LOG_ERR("Calibration is not supported");
return -EINVAL;
}
if (!seq->buffer) {
LOG_ERR("Buffer invalid");
return -EINVAL;
}
if (seq->buffer_size < (num_samples * sizeof(tla2021_reg_data_t))) {
LOG_ERR("buffer size too small");
return -EINVAL;
}
data->buffer = seq->buffer;
adc_context_start_read(&data->ctx, seq);
return adc_context_wait_for_completion(&data->ctx);
}
static int tla2021_read_async(const struct device *dev, const struct adc_sequence *seq,
struct k_poll_signal *async)
{
int ret;
struct tla2021_data *data = dev->data;
adc_context_lock(&data->ctx, async ? true : false, async);
ret = tla2021_start_read(dev, seq);
adc_context_release(&data->ctx, ret);
return ret;
}
static int tla2021_read(const struct device *dev, const struct adc_sequence *seq)
{
return tla2021_read_async(dev, seq, NULL);
}
static void adc_context_start_sampling(struct adc_context *ctx)
{
int ret;
struct tla2021_data *data = CONTAINER_OF(ctx, struct tla2021_data, ctx);
const struct device *dev = data->dev;
tla2021_reg_config_t reg = data->reg_config;
/*
* Start single-shot conversion
*/
WRITE_BIT(reg, REG_CONFIG_MODE_pos, 1);
WRITE_BIT(reg, REG_CONFIG_OS_pos, 1);
ret = tla2021_write_register(dev, REG_CONFIG, reg);
if (ret) {
LOG_WRN("Failed to start conversion");
}
data->repeat_buffer = data->buffer;
k_sem_give(&data->acq_lock);
}
static void adc_context_update_buffer_pointer(struct adc_context *ctx, bool repeat_sampling)
{
struct tla2021_data *data = CONTAINER_OF(ctx, struct tla2021_data, ctx);
if (repeat_sampling) {
data->buffer = data->repeat_buffer;
}
}
static void tla2021_acq_thread_fn(void *p1, void *p2, void *p3)
{
int ret;
struct tla2021_data *data = p1;
const struct device *dev = data->dev;
while (true) {
k_sem_take(&data->acq_lock, K_FOREVER);
tla2021_reg_config_t reg;
tla2021_reg_data_t res;
/*
* Wait until sampling is done
*/
do {
ret = tla2021_read_register(dev, REG_CONFIG, &reg);
if (ret < 0) {
adc_context_complete(&data->ctx, ret);
}
} while (!(reg & REG_CONFIG_OS_msk));
/*
* Read result
*/
ret = tla2021_read_register(dev, REG_DATA, &res);
if (ret) {
adc_context_complete(&data->ctx, ret);
}
/*
* ADC data is stored in the upper 12 bits
*/
res >>= REG_DATA_pos;
*data->buffer++ = res;
adc_context_on_sampling_done(&data->ctx, data->dev);
}
}
static int tla2021_init(const struct device *dev)
{
int ret;
const struct tla2021_config *config = dev->config;
struct tla2021_data *data = dev->data;
k_sem_init(&data->acq_lock, 0, 1);
if (!i2c_is_ready_dt(&config->bus)) {
LOG_ERR("Bus not ready");
return -EINVAL;
}
ret = tla2021_write_register(dev, REG_CONFIG, data->reg_config);
if (ret) {
LOG_ERR("Device reset failed: %d", ret);
return ret;
}
adc_context_unlock_unconditionally(&data->ctx);
return 0;
}
static const struct adc_driver_api tla2021_driver_api = {
.channel_setup = tla2021_channel_setup,
.read = tla2021_read,
.ref_internal = 4096,
#ifdef CONFIG_ADC_ASYNC
.read_async = tla2021_read_async,
#endif
};
#define TLA2021_INIT(n) \
static const struct tla2021_config inst_##n##_config; \
static struct tla2021_data inst_##n##_data; \
K_THREAD_DEFINE(inst_##n##_thread, ACQ_THREAD_STACK_SIZE, tla2021_acq_thread_fn, \
&inst_##n##_data, NULL, NULL, ACQ_THREAD_PRIORITY, 0, 0); \
static const struct tla2021_config inst_##n##_config = { \
.bus = I2C_DT_SPEC_INST_GET(n), \
.acq_thread_id = inst_##n##_thread, \
}; \
static struct tla2021_data inst_##n##_data = { \
.dev = DEVICE_DT_INST_GET(n), \
ADC_CONTEXT_INIT_LOCK(inst_##n##_data, ctx), \
ADC_CONTEXT_INIT_TIMER(inst_##n##_data, ctx), \
ADC_CONTEXT_INIT_SYNC(inst_##n##_data, ctx), \
.reg_config = REG_CONFIG_DEFAULT, \
}; \
DEVICE_DT_INST_DEFINE(n, &tla2021_init, NULL, &inst_##n##_data, &inst_##n##_config, \
POST_KERNEL, CONFIG_ADC_TLA2021_INIT_PRIORITY, &tla2021_driver_api);
DT_INST_FOREACH_STATUS_OKAY(TLA2021_INIT)
BUILD_ASSERT(CONFIG_I2C_INIT_PRIORITY < CONFIG_ADC_TLA2021_INIT_PRIORITY);