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zephyr/drivers/adc/adc_tla202x.c
Benjamin Bigler f1087d2042 drivers: adc: tla202x: add support for tla2022 and tla2024 
This extends the tla2021 driver to support tla2022 and tla2024

Signed-off-by: Benjamin Bigler <benjamin.bigler@securiton.ch>
2024-12-18 08:33:49 +01:00

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/*
* 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"
LOG_MODULE_REGISTER(tla2021, CONFIG_ADC_LOG_LEVEL);
#define ACQ_THREAD_PRIORITY CONFIG_ADC_TLA202X_ACQUISITION_THREAD_PRIORITY
#define ACQ_THREAD_STACK_SIZE CONFIG_ADC_TLA202X_ACQUISITION_THREAD_STACK_SIZE
#define MAX_CHANNELS 4
#define ADC_RESOLUTION 12
#define WAKEUP_TIME_US 25
#define CONVERSION_TIME_US 625 /* DR is 1600 SPS */
/*
* 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 /* TLA2024 Only */
#define REG_CONFIG_PGA_msk GENMASK(11, 9) /* TLA2022 and TLA2024 Only */
#define REG_CONFIG_MUX_pos 12 /* TLA2024 Only */
#define REG_CONFIG_MUX_msk GENMASK(14, 12) /* TLA2024 Only */
#define REG_CONFIG_OS_pos 15
#define REG_CONFIG_OS_msk (BIT_MASK(1) << REG_CONFIG_OS_pos)
enum {
MUX_DIFF_0_1 = 0,
MUX_DIFF_0_3 = 1,
MUX_DIFF_1_3 = 2,
MUX_DIFF_2_3 = 3,
MUX_SINGLE_0 = 4,
MUX_SINGLE_1 = 5,
MUX_SINGLE_2 = 6,
MUX_SINGLE_3 = 7,
};
enum {
/* Gain 1/3 */
PGA_6144 = 0,
/* Gain 1/2 */
PGA_4096 = 1,
/* Gain 1 (Default) */
PGA_2048 = 2,
/* Gain 2 */
PGA_1024 = 3,
/* Gain 4 */
PGA_512 = 4,
/* Gain 8 */
PGA_256 = 5
};
typedef int16_t tla202x_reg_data_t;
typedef uint16_t tla202x_reg_config_t;
struct tla202x_config {
const struct i2c_dt_spec bus;
bool has_pga;
uint8_t channel_count;
};
struct tla202x_data {
const struct device *dev;
struct adc_context ctx;
#ifdef CONFIG_ADC_ASYNC
struct k_sem acq_lock;
#endif
tla202x_reg_data_t *buffer;
tla202x_reg_data_t *repeat_buffer;
uint8_t channels;
/*
* Shadow register
*/
tla202x_reg_config_t reg_config[MAX_CHANNELS];
};
static int tla202x_read_register(const struct device *dev, uint8_t reg, uint16_t *value)
{
int ret;
const struct tla202x_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 tla202x_write_register(const struct device *dev, uint8_t reg, uint16_t value)
{
int ret;
const struct tla202x_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 tla202x_channel_setup(const struct device *dev, const struct adc_channel_cfg *cfg)
{
const struct tla202x_config *config = dev->config;
struct tla202x_data *data = dev->data;
if (cfg->channel_id >= config->channel_count) {
LOG_ERR("invalid channel selection %u", cfg->channel_id);
return -EINVAL;
}
tla202x_reg_config_t *reg_config = &data->reg_config[cfg->channel_id];
if (config->has_pga) {
*reg_config &= ~REG_CONFIG_PGA_msk;
switch (cfg->gain) {
case ADC_GAIN_1_3:
*reg_config |= PGA_6144 << REG_CONFIG_PGA_pos;
break;
case ADC_GAIN_1_2:
*reg_config |= PGA_4096 << REG_CONFIG_PGA_pos;
break;
case ADC_GAIN_1:
*reg_config |= PGA_2048 << REG_CONFIG_PGA_pos;
break;
case ADC_GAIN_2:
*reg_config |= PGA_1024 << REG_CONFIG_PGA_pos;
break;
case ADC_GAIN_4:
*reg_config |= PGA_512 << REG_CONFIG_PGA_pos;
break;
case ADC_GAIN_8:
*reg_config |= PGA_256 << REG_CONFIG_PGA_pos;
break;
default:
LOG_ERR("Invalid gain");
return -EINVAL;
}
} else {
if (cfg->gain != ADC_GAIN_1) {
LOG_ERR("Invalid gain");
return -EINVAL;
}
}
/*
* Only adc with more than one channels has a mux
*/
#if defined(CONFIG_ADC_CONFIGURABLE_INPUTS)
if (config->channel_count > 1) {
*reg_config &= ~REG_CONFIG_MUX_msk;
if (cfg->differential) {
if (cfg->input_positive == 0 && cfg->input_negative == 1) {
*reg_config |= MUX_DIFF_0_1 << REG_CONFIG_MUX_pos;
} else if (cfg->input_positive == 0 && cfg->input_negative == 3) {
*reg_config |= MUX_DIFF_0_3 << REG_CONFIG_MUX_pos;
} else if (cfg->input_positive == 1 && cfg->input_negative == 3) {
*reg_config |= MUX_DIFF_1_3 << REG_CONFIG_MUX_pos;
} else if (cfg->input_positive == 2 && cfg->input_negative == 3) {
*reg_config |= MUX_DIFF_2_3 << REG_CONFIG_MUX_pos;
} else {
LOG_ERR("Invalid channel config");
return -EINVAL;
}
} else {
if (cfg->input_positive == 0) {
*reg_config |= MUX_SINGLE_0 << REG_CONFIG_MUX_pos;
} else if (cfg->input_positive == 1) {
*reg_config |= MUX_SINGLE_1 << REG_CONFIG_MUX_pos;
} else if (cfg->input_positive == 2) {
*reg_config |= MUX_SINGLE_2 << REG_CONFIG_MUX_pos;
} else if (cfg->input_positive == 3) {
*reg_config |= MUX_SINGLE_3 << REG_CONFIG_MUX_pos;
} else {
LOG_ERR("Invalid channel config");
return -EINVAL;
}
}
}
#endif
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 tla202x_start_read(const struct device *dev, const struct adc_sequence *seq)
{
struct tla202x_data *data = dev->data;
const struct tla202x_config *config = dev->config;
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 (find_msb_set(seq->channels) > config->channel_count) {
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(tla202x_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 tla202x_read_async(const struct device *dev, const struct adc_sequence *seq,
struct k_poll_signal *async)
{
int ret;
struct tla202x_data *data = dev->data;
adc_context_lock(&data->ctx, async ? true : false, async);
ret = tla202x_start_read(dev, seq);
adc_context_release(&data->ctx, ret);
return ret;
}
static int tla202x_read(const struct device *dev, const struct adc_sequence *seq)
{
return tla202x_read_async(dev, seq, NULL);
}
static void tla202x_perform_read(const struct device *dev)
{
struct tla202x_data *data = dev->data;
tla202x_reg_config_t reg;
tla202x_reg_data_t res;
uint8_t ch;
int ret;
while (data->channels) {
/*
* Select correct channel
*/
ch = find_lsb_set(data->channels) - 1;
reg = data->reg_config[ch];
LOG_DBG("reg: %x", reg);
/*
* Start single-shot conversion
*/
WRITE_BIT(reg, REG_CONFIG_MODE_pos, 1);
WRITE_BIT(reg, REG_CONFIG_OS_pos, 1);
ret = tla202x_write_register(dev, REG_CONFIG, reg);
if (ret) {
LOG_WRN("Failed to start conversion");
}
/*
* Wait until sampling is done
*/
k_usleep(WAKEUP_TIME_US + CONVERSION_TIME_US);
do {
k_yield();
ret = tla202x_read_register(dev, REG_CONFIG, &reg);
if (ret < 0) {
adc_context_complete(&data->ctx, ret);
}
} while (!(reg & REG_CONFIG_OS_msk));
/*
* Read result
*/
ret = tla202x_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;
LOG_DBG("read channel %d, result = %d", ch, res);
WRITE_BIT(data->channels, ch, 0);
}
adc_context_on_sampling_done(&data->ctx, data->dev);
}
static void adc_context_start_sampling(struct adc_context *ctx)
{
struct tla202x_data *data = CONTAINER_OF(ctx, struct tla202x_data, ctx);
const struct device *dev = data->dev;
data->channels = ctx->sequence.channels;
data->repeat_buffer = data->buffer;
#ifdef CONFIG_ADC_ASYNC
k_sem_give(&data->acq_lock);
#else
tla202x_perform_read(dev);
#endif
}
static void adc_context_update_buffer_pointer(struct adc_context *ctx, bool repeat_sampling)
{
struct tla202x_data *data = CONTAINER_OF(ctx, struct tla202x_data, ctx);
if (repeat_sampling) {
data->buffer = data->repeat_buffer;
}
}
#ifdef CONFIG_ADC_ASYNC
static void tla202x_acq_thread_fn(void *p1, void *p2, void *p3)
{
const struct device *dev = p1;
struct tla202x_data *data = dev->data;
while (true) {
k_sem_take(&data->acq_lock, K_FOREVER);
tla202x_perform_read(dev);
}
}
#endif
static int tla202x_init(const struct device *dev)
{
int ret;
const struct tla202x_config *config = dev->config;
struct tla202x_data *data = dev->data;
if (!i2c_is_ready_dt(&config->bus)) {
LOG_ERR("Bus not ready");
return -EINVAL;
}
for (uint8_t ch = 0; ch < MAX_CHANNELS; ch++) {
data->reg_config[ch] = REG_CONFIG_DEFAULT;
}
ret = tla202x_write_register(dev, REG_CONFIG, data->reg_config[0]);
if (ret) {
LOG_ERR("Device reset failed: %d", ret);
return ret;
}
adc_context_unlock_unconditionally(&data->ctx);
return 0;
}
static DEVICE_API(adc, tla202x_driver_api) = {
.channel_setup = tla202x_channel_setup,
.read = tla202x_read,
.ref_internal = 4096,
#ifdef CONFIG_ADC_ASYNC
.read_async = tla202x_read_async,
#endif
};
#define TLA202X_THREAD_INIT(t, n) \
K_THREAD_DEFINE(adc_##t##_##n##_thread, ACQ_THREAD_STACK_SIZE, tla202x_acq_thread_fn, \
DEVICE_DT_INST_GET(n), NULL, NULL, ACQ_THREAD_PRIORITY, 0, 0);
#define TLA202X_INIT(n, t, pga, channels) \
IF_ENABLED(CONFIG_ADC_ASYNC, (TLA202X_THREAD_INIT(t, n))) \
static const struct tla202x_config inst_##t##_##n##_config = { \
.bus = I2C_DT_SPEC_INST_GET(n), \
.has_pga = pga, \
.channel_count = channels, \
}; \
static struct tla202x_data inst_##t##_##n##_data = { \
.dev = DEVICE_DT_INST_GET(n), \
ADC_CONTEXT_INIT_LOCK(inst_##t##_##n##_data, ctx), \
ADC_CONTEXT_INIT_TIMER(inst_##t##_##n##_data, ctx), \
ADC_CONTEXT_INIT_SYNC(inst_##t##_##n##_data, ctx), \
IF_ENABLED(CONFIG_ADC_ASYNC, \
(.acq_lock = Z_SEM_INITIALIZER(inst_##t##_##n##_data.acq_lock, 0, 1),)) \
}; \
DEVICE_DT_INST_DEFINE(n, &tla202x_init, NULL, &inst_##t##_##n##_data, \
&inst_##t##_##n##_config, POST_KERNEL, \
CONFIG_ADC_TLA202X_INIT_PRIORITY, &tla202x_driver_api);
#define DT_DRV_COMPAT ti_tla2021
#define ADC_TLA2021_CHANNELS 1
#define ADC_TLA2021_PGA false
DT_INST_FOREACH_STATUS_OKAY_VARGS(TLA202X_INIT, tla2021, ADC_TLA2021_PGA, ADC_TLA2021_CHANNELS)
#undef DT_DRV_COMPAT
#define DT_DRV_COMPAT ti_tla2022
#define ADC_TLA2022_CHANNELS 1
#define ADC_TLA2022_PGA true
DT_INST_FOREACH_STATUS_OKAY_VARGS(TLA202X_INIT, tla2022, ADC_TLA2022_PGA, ADC_TLA2022_CHANNELS)
#undef DT_DRV_COMPAT
#define DT_DRV_COMPAT ti_tla2024
#define ADC_TLA2024_CHANNELS 4
#define ADC_TLA2024_PGA true
DT_INST_FOREACH_STATUS_OKAY_VARGS(TLA202X_INIT, tla2024, ADC_TLA2024_PGA, ADC_TLA2024_CHANNELS)
#undef DT_DRV_COMPAT
BUILD_ASSERT(CONFIG_I2C_INIT_PRIORITY < CONFIG_ADC_TLA202X_INIT_PRIORITY);
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