zephyr/drivers/adc/adc_b91.c

465 lines
11 KiB
C

/*
* Copyright (c) 2022 Telink Semiconductor
*
* SPDX-License-Identifier: Apache-2.0
*/
#define DT_DRV_COMPAT telink_b91_adc
/* Local driver headers */
#define ADC_CONTEXT_USES_KERNEL_TIMER
#include "adc_context.h"
/* Zephyr Device Tree headers */
#include <zephyr/dt-bindings/adc/b91-adc.h>
/* Zephyr Logging headers */
#include <zephyr/logging/log.h>
LOG_MODULE_REGISTER(adc_b91, CONFIG_ADC_LOG_LEVEL);
/* Telink HAL headers */
#include <adc.h>
/* ADC B91 defines */
#define SIGN_BIT_POSITION (13)
#define AREG_ADC_DATA_STATUS (0xf6)
#define ADC_DATA_READY BIT(0)
/* B91 ADC driver data */
struct b91_adc_data {
struct adc_context ctx;
int16_t *buffer;
int16_t *repeat_buffer;
uint8_t differential;
uint8_t resolution_divider;
struct k_sem acq_sem;
struct k_thread thread;
K_THREAD_STACK_MEMBER(stack, CONFIG_ADC_B91_ACQUISITION_THREAD_STACK_SIZE);
};
struct b91_adc_cfg {
uint32_t sample_freq;
uint16_t vref_internal_mv;
};
/* Validate ADC data buffer size */
static int adc_b91_validate_buffer_size(const struct adc_sequence *sequence)
{
size_t needed = sizeof(int16_t);
if (sequence->options) {
needed *= (1 + sequence->options->extra_samplings);
}
if (sequence->buffer_size < needed) {
return -ENOMEM;
}
return 0;
}
/* Validate ADC read API input parameters */
static int adc_b91_validate_sequence(const struct adc_sequence *sequence)
{
int status;
if (sequence->channels != BIT(0)) {
LOG_ERR("Only channel 0 is supported.");
return -ENOTSUP;
}
if (sequence->oversampling) {
LOG_ERR("Oversampling is not supported.");
return -ENOTSUP;
}
status = adc_b91_validate_buffer_size(sequence);
if (status) {
LOG_ERR("Buffer size too small.");
return status;
}
return 0;
}
/* Convert dts pin to B91 SDK pin */
static adc_input_pin_def_e adc_b91_get_pin(uint8_t dt_pin)
{
adc_input_pin_def_e adc_pin;
switch (dt_pin) {
case DT_ADC_GPIO_PB0:
adc_pin = ADC_GPIO_PB0;
break;
case DT_ADC_GPIO_PB1:
adc_pin = ADC_GPIO_PB1;
break;
case DT_ADC_GPIO_PB2:
adc_pin = ADC_GPIO_PB2;
break;
case DT_ADC_GPIO_PB3:
adc_pin = ADC_GPIO_PB3;
break;
case DT_ADC_GPIO_PB4:
adc_pin = ADC_GPIO_PB4;
break;
case DT_ADC_GPIO_PB5:
adc_pin = ADC_GPIO_PB5;
break;
case DT_ADC_GPIO_PB6:
adc_pin = ADC_GPIO_PB6;
break;
case DT_ADC_GPIO_PB7:
adc_pin = ADC_GPIO_PB7;
break;
case DT_ADC_GPIO_PD0:
adc_pin = ADC_GPIO_PD0;
break;
case DT_ADC_GPIO_PD1:
adc_pin = ADC_GPIO_PD1;
break;
case DT_ADC_VBAT:
adc_pin = ADC_VBAT;
break;
default:
adc_pin = NOINPUTN;
break;
}
return adc_pin;
}
/* Get ADC value */
static signed short adc_b91_get_code(void)
{
signed short adc_code;
analog_write_reg8(areg_adc_data_sample_control,
analog_read_reg8(areg_adc_data_sample_control) | FLD_NOT_SAMPLE_ADC_DATA);
adc_code = analog_read_reg16(areg_adc_misc_l);
analog_write_reg8(areg_adc_data_sample_control,
analog_read_reg8(areg_adc_data_sample_control) & (~FLD_NOT_SAMPLE_ADC_DATA));
return adc_code;
}
/* ADC Context API implementation: start sampling */
static void adc_context_start_sampling(struct adc_context *ctx)
{
struct b91_adc_data *data =
CONTAINER_OF(ctx, struct b91_adc_data, ctx);
data->repeat_buffer = data->buffer;
adc_power_on();
k_sem_give(&data->acq_sem);
}
/* ADC Context API implementation: buffer pointer */
static void adc_context_update_buffer_pointer(struct adc_context *ctx, bool repeat_sampling)
{
struct b91_adc_data *data =
CONTAINER_OF(ctx, struct b91_adc_data, ctx);
if (repeat_sampling) {
data->buffer = data->repeat_buffer;
}
}
/* Start ADC measurements */
static int adc_b91_adc_start_read(const struct device *dev, const struct adc_sequence *sequence)
{
int status;
struct b91_adc_data *data = dev->data;
/* Validate input parameters */
status = adc_b91_validate_sequence(sequence);
if (status != 0) {
return status;
}
/* Set resolution */
switch (sequence->resolution) {
case 14:
adc_set_resolution(ADC_RES14);
data->resolution_divider = 1;
break;
case 12:
adc_set_resolution(ADC_RES12);
data->resolution_divider = 4;
break;
case 10:
adc_set_resolution(ADC_RES10);
data->resolution_divider = 16;
break;
case 8:
adc_set_resolution(ADC_RES8);
data->resolution_divider = 64;
break;
default:
LOG_ERR("Selected ADC resolution is not supported.");
return -EINVAL;
}
/* Save buffer */
data->buffer = sequence->buffer;
/* Start ADC conversion */
adc_context_start_read(&data->ctx, sequence);
return adc_context_wait_for_completion(&data->ctx);
}
/* Main ADC Acquisition thread */
static void adc_b91_acquisition_thread(const struct device *dev)
{
int16_t adc_code;
struct b91_adc_data *data = dev->data;
while (true) {
/* Wait for Acquisition semaphore */
k_sem_take(&data->acq_sem, K_FOREVER);
/* Wait for ADC data ready */
while ((analog_read_reg8(AREG_ADC_DATA_STATUS) & ADC_DATA_READY)
!= ADC_DATA_READY) {
}
/* Perform read */
adc_code = (adc_b91_get_code() / data->resolution_divider);
if (!data->differential) {
/* Sign bit is not used in case of single-ended configuration */
adc_code = adc_code * 2;
/* Do not return negative value for single-ended configuration */
if (adc_code < 0) {
adc_code = 0;
}
}
*data->buffer++ = adc_code;
/* Power off ADC */
adc_power_off();
/* Release ADC context */
adc_context_on_sampling_done(&data->ctx, dev);
}
}
/* ADC Driver initialization */
static int adc_b91_init(const struct device *dev)
{
struct b91_adc_data *data = dev->data;
k_sem_init(&data->acq_sem, 0, 1);
k_thread_create(&data->thread, data->stack,
CONFIG_ADC_B91_ACQUISITION_THREAD_STACK_SIZE,
(k_thread_entry_t)adc_b91_acquisition_thread,
(void *)dev, NULL, NULL,
CONFIG_ADC_B91_ACQUISITION_THREAD_PRIO,
0, K_NO_WAIT);
adc_context_unlock_unconditionally(&data->ctx);
return 0;
}
/* API implementation: channel_setup */
static int adc_b91_channel_setup(const struct device *dev,
const struct adc_channel_cfg *channel_cfg)
{
adc_ref_vol_e vref_internal_mv;
adc_sample_freq_e sample_freq;
adc_pre_scale_e pre_scale;
adc_sample_cycle_e sample_cycl;
adc_input_pin_def_e input_positive;
adc_input_pin_def_e input_negative;
struct b91_adc_data *data = dev->data;
const struct b91_adc_cfg *config = dev->config;
/* Check channel ID */
if (channel_cfg->channel_id > 0) {
LOG_ERR("Only channel 0 is supported.");
return -EINVAL;
}
/* Check reference */
if (channel_cfg->reference != ADC_REF_INTERNAL) {
LOG_ERR("Selected ADC reference is not supported.");
return -EINVAL;
}
/* Check internal reference */
switch (config->vref_internal_mv) {
case 900:
vref_internal_mv = ADC_VREF_0P9V;
break;
case 1200:
vref_internal_mv = ADC_VREF_1P2V;
break;
default:
LOG_ERR("Selected reference voltage is not supported.");
return -EINVAL;
}
/* Check sample frequency */
switch (config->sample_freq) {
case 23000:
sample_freq = ADC_SAMPLE_FREQ_23K;
break;
case 48000:
sample_freq = ADC_SAMPLE_FREQ_48K;
break;
case 96000:
sample_freq = ADC_SAMPLE_FREQ_96K;
break;
default:
LOG_ERR("Selected sample frequency is not supported.");
return -EINVAL;
}
/* Check gain */
switch (channel_cfg->gain) {
case ADC_GAIN_1:
pre_scale = ADC_PRESCALE_1;
break;
case ADC_GAIN_1_4:
pre_scale = ADC_PRESCALE_1F4;
break;
default:
LOG_ERR("Selected ADC gain is not supported.");
return -EINVAL;
}
/* Check acquisition time */
switch (channel_cfg->acquisition_time) {
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 3):
sample_cycl = ADC_SAMPLE_CYC_3;
break;
case ADC_ACQ_TIME_DEFAULT:
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 6):
sample_cycl = ADC_SAMPLE_CYC_6;
break;
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 9):
sample_cycl = ADC_SAMPLE_CYC_9;
break;
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 12):
sample_cycl = ADC_SAMPLE_CYC_12;
break;
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 18):
sample_cycl = ADC_SAMPLE_CYC_18;
break;
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 24):
sample_cycl = ADC_SAMPLE_CYC_24;
break;
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 36):
sample_cycl = ADC_SAMPLE_CYC_36;
break;
case ADC_ACQ_TIME(ADC_ACQ_TIME_TICKS, 48):
sample_cycl = ADC_SAMPLE_CYC_48;
break;
default:
LOG_ERR("Selected ADC acquisition time is not supported.");
return -EINVAL;
}
/* Check for valid pins configuration */
input_positive = adc_b91_get_pin(channel_cfg->input_positive);
input_negative = adc_b91_get_pin(channel_cfg->input_negative);
if ((input_positive == (uint8_t)ADC_VBAT || input_negative == (uint8_t)ADC_VBAT) &&
channel_cfg->differential) {
LOG_ERR("VBAT pin is not available for differential mode.");
return -EINVAL;
} else if (channel_cfg->differential && (input_negative == (uint8_t)NOINPUTN)) {
LOG_ERR("Negative input is not selected.");
return -EINVAL;
}
/* Init ADC */
data->differential = channel_cfg->differential;
adc_init(vref_internal_mv, pre_scale, sample_freq);
adc_set_vbat_divider(ADC_VBAT_DIV_OFF);
adc_set_tsample_cycle(sample_cycl);
/* Init ADC Pins */
if (channel_cfg->differential) {
/* Differential pins configuration */
adc_pin_config(ADC_GPIO_MODE, input_positive);
adc_pin_config(ADC_GPIO_MODE, input_negative);
adc_set_diff_input(channel_cfg->input_positive, channel_cfg->input_negative);
} else if (input_positive == (uint8_t)ADC_VBAT) {
/* Single-ended Vbat pin configuration */
adc_set_diff_input(ADC_VBAT, GND);
} else {
/* Single-ended GPIO pin configuration */
adc_pin_config(ADC_GPIO_MODE, input_positive);
adc_set_diff_input(channel_cfg->input_positive, GND);
}
return 0;
}
/* API implementation: read */
static int adc_b91_read(const struct device *dev,
const struct adc_sequence *sequence)
{
int status;
struct b91_adc_data *data = dev->data;
adc_context_lock(&data->ctx, false, NULL);
status = adc_b91_adc_start_read(dev, sequence);
adc_context_release(&data->ctx, status);
return status;
}
#ifdef CONFIG_ADC_ASYNC
/* API implementation: read_async */
static int adc_b91_read_async(const struct device *dev,
const struct adc_sequence *sequence,
struct k_poll_signal *async)
{
int status;
struct b91_adc_data *data = dev->data;
adc_context_lock(&data->ctx, true, async);
status = adc_b91_adc_start_read(dev, sequence);
adc_context_release(&data->ctx, status);
return status;
}
#endif /* CONFIG_ADC_ASYNC */
static struct b91_adc_data data_0 = {
ADC_CONTEXT_INIT_TIMER(data_0, ctx),
ADC_CONTEXT_INIT_LOCK(data_0, ctx),
ADC_CONTEXT_INIT_SYNC(data_0, ctx),
};
static const struct b91_adc_cfg cfg_0 = {
.sample_freq = DT_INST_PROP(0, sample_freq),
.vref_internal_mv = DT_INST_PROP(0, vref_internal_mv),
};
static const struct adc_driver_api adc_b91_driver_api = {
.channel_setup = adc_b91_channel_setup,
.read = adc_b91_read,
#ifdef CONFIG_ADC_ASYNC
.read_async = adc_b91_read_async,
#endif
.ref_internal = cfg_0.vref_internal_mv,
};
DEVICE_DT_INST_DEFINE(0, adc_b91_init, NULL,
&data_0, &cfg_0,
POST_KERNEL,
CONFIG_ADC_INIT_PRIORITY,
&adc_b91_driver_api);