static int adc_stm32_read(struct device *dev,
const struct adc_sequence *sequence)
{
struct adc_stm32_data *data = dev->driver_data;
int error;
adc_context_lock(&data->ctx, false, NULL);
error = start_read(dev, sequence);
adc_context_release(&data->ctx, error);
return error;
}
static int adc_stm32_read_async(struct device *dev,
const struct adc_sequence *sequence,
struct k_poll_signal *async)
{
struct adc_stm32_data *data = dev->driver_data;
int error;
adc_context_lock(&data->ctx, true, async);
error = start_read(dev, sequence);
adc_context_release(&data->ctx, error);
return error;
}
static int start_read(struct device *dev, const struct adc_sequence *sequence)
{
int error = 0;
u32_t selected_channels = sequence->channels;
u8_t active_channels;
u8_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 != 0) {
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 = 0;
nrfx_adc_all_channels_disable();
/* Enable the channels selected for the pointed sequence.
*/
channel_id = 0;
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);
if (!error) {
error = adc_context_wait_for_completion(&m_data.ctx);
adc_context_release(&m_data.ctx, error);
}
return error;
}
