75 lines
1.6 KiB
C
75 lines
1.6 KiB
C
|
#include <inttypes.h>
|
||
|
|
#include <stddef.h>
|
||
|
|
#include <stdint.h>
|
||
|
|
|
||
|
|
#include <zephyr/device.h>
|
||
|
|
#include <zephyr/devicetree.h>
|
||
|
|
#include <zephyr/drivers/adc.h>
|
||
|
|
#include <zephyr/kernel.h>
|
||
|
|
|
||
|
|
/** Setup code referenced from Zephyr ADC example **/
|
||
|
|
#if !DT_NODE_EXISTS(DT_PATH(zephyr_user)) || \
|
||
|
|
!DT_NODE_HAS_PROP(DT_PATH(zephyr_user), io_channels)
|
||
|
|
#error "No suitable devicetree overlay specified"
|
||
|
|
#endif
|
||
|
|
|
||
|
|
#define DT_SPEC_AND_COMMA(node_id, prop, idx) \
|
||
|
|
ADC_DT_SPEC_GET_BY_IDX(node_id, idx),
|
||
|
|
|
||
|
|
static const struct adc_dt_spec adc_channels[] = {
|
||
|
|
DT_FOREACH_PROP_ELEM(DT_PATH(zephyr_user), io_channels, DT_SPEC_AND_COMMA)
|
||
|
|
};
|
||
|
|
|
||
|
|
static int setup = 0;
|
||
|
|
|
||
|
|
int
|
||
|
|
adc_init()
|
||
|
|
{
|
||
|
|
for (int i = 0; i < ARRAY_SIZE(adc_channels); i++) {
|
||
|
|
int err;
|
||
|
|
const struct adc_dt_spec *chan = &adc_channels[i];
|
||
|
|
|
||
|
|
if (!adc_is_ready_dt(chan)) {
|
||
|
|
return (-1);
|
||
|
|
}
|
||
|
|
|
||
|
|
err = adc_channel_setup_dt(chan);
|
||
|
|
if (err) {
|
||
|
|
return (err);
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
setup = 1;
|
||
|
|
return (0);
|
||
|
|
}
|
||
|
|
|
||
|
|
int
|
||
|
|
adc_get_mv(int channel)
|
||
|
|
{
|
||
|
|
uint16_t val_raw;
|
||
|
|
int32_t val_mv;
|
||
|
|
struct adc_sequence seq = {
|
||
|
|
.buffer = &val_raw,
|
||
|
|
.buffer_size = sizeof(val_raw)
|
||
|
|
};
|
||
|
|
const struct adc_dt_spec *chan;
|
||
|
|
|
||
|
|
if ((channel >= ARRAY_SIZE(adc_channels)) ||
|
||
|
|
(!setup)) {
|
||
|
|
return (INT32_MIN);
|
||
|
|
}
|
||
|
|
|
||
|
|
chan = &adc_channels[channel];
|
||
|
|
adc_sequence_init_dt(chan, &seq);
|
||
|
|
|
||
|
|
if (adc_read_dt(chan, &seq) < 0) {
|
||
|
|
return (INT32_MIN);
|
||
|
|
}
|
||
|
|
|
||
|
|
val_mv = (int32_t)val_raw;
|
||
|
|
if (adc_raw_to_millivolts_dt(chan, &val_mv)) {
|
||
|
|
return (INT32_MIN);
|
||
|
|
}
|
||
|
|
|
||
|
|
return (val_mv);
|
||
|
|
}
|