drivers: adc: Implement the current sources of ADS114S08
Implement support for the current sources of ADS114S08.
Signed-off-by: Benedikt Schmidt <benedikt.schmidt@embedded-solutions.at>
diff --git a/drivers/adc/Kconfig.ads114s0x b/drivers/adc/Kconfig.ads114s0x
index 39ed5c5..31f1939 100644
--- a/drivers/adc/Kconfig.ads114s0x
+++ b/drivers/adc/Kconfig.ads114s0x
@@ -8,6 +8,7 @@
depends on DT_HAS_TI_ADS114S08_ENABLED
select SPI
select ADC_CONFIGURABLE_INPUTS
+ select ADC_CONFIGURABLE_EXCITATION_CURRENT_SOURCE_PIN
help
Enable the driver implementation for the ADS114S0X family
diff --git a/drivers/adc/adc_ads114s0x.c b/drivers/adc/adc_ads114s0x.c
index 8885c00..eeafd0d 100644
--- a/drivers/adc/adc_ads114s0x.c
+++ b/drivers/adc/adc_ads114s0x.c
@@ -381,6 +381,22 @@
ADS114S0X_REGISTER_PGA_DELAY_SET(target, 0b000); \
ADS114S0X_REGISTER_PGA_PGA_EN_SET(target, 0b00); \
ADS114S0X_REGISTER_PGA_GAIN_SET(target, 0b000)
+/*
+ * - disable PGA output rail flag
+ * - low-side power switch
+ * - IDAC off
+ */
+#define ADS114S0X_REGISTER_IDACMAG_SET_DEFAULTS(target) \
+ ADS114S0X_REGISTER_IDACMAG_FL_RAIL_EN_SET(target, 0b0); \
+ ADS114S0X_REGISTER_IDACMAG_PSW_SET(target, 0b0); \
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(target, 0b0000)
+/*
+ * - disconnect IDAC1
+ * - disconnect IDAC2
+ */
+#define ADS114S0X_REGISTER_IDACMUX_SET_DEFAULTS(target) \
+ ADS114S0X_REGISTER_IDACMUX_I1MUX_SET(target, 0b1111); \
+ ADS114S0X_REGISTER_IDACMUX_I2MUX_SET(target, 0b1111)
struct ads114s0x_config {
struct spi_dt_spec bus;
@@ -390,6 +406,7 @@
const struct gpio_dt_spec gpio_reset;
const struct gpio_dt_spec gpio_data_ready;
const struct gpio_dt_spec gpio_start_sync;
+ int idac_current;
};
struct ads114s0x_data {
@@ -570,14 +587,20 @@
uint8_t reference_control = 0;
uint8_t data_rate = 0;
uint8_t gain = 0;
+ uint8_t idac_magnitude = 0;
+ uint8_t idac_mux = 0;
+ uint8_t pin_selections[4];
+ size_t pin_selections_size;
int result;
- enum ads114s0x_register register_addresses[4];
+ enum ads114s0x_register register_addresses[6];
uint8_t values[ARRAY_SIZE(register_addresses)];
ADS114S0X_REGISTER_INPMUX_SET_DEFAULTS(gain);
ADS114S0X_REGISTER_REF_SET_DEFAULTS(reference_control);
ADS114S0X_REGISTER_DATARATE_SET_DEFAULTS(data_rate);
ADS114S0X_REGISTER_PGA_SET_DEFAULTS(gain);
+ ADS114S0X_REGISTER_IDACMAG_SET_DEFAULTS(idac_magnitude);
+ ADS114S0X_REGISTER_IDACMUX_SET_DEFAULTS(idac_mux);
if (channel_cfg->channel_id != 0) {
LOG_ERR("only one channel is supported");
@@ -634,6 +657,8 @@
ADS114S0X_REGISTER_INPMUX_MUXP_SET(input_mux, channel_cfg->input_positive);
ADS114S0X_REGISTER_INPMUX_MUXN_SET(input_mux, channel_cfg->input_negative);
+ pin_selections[0] = channel_cfg->input_positive;
+ pin_selections[1] = channel_cfg->input_negative;
} else {
if (channel_cfg->input_positive >= ADS114S0X_INPUT_SELECTION_AINCOM) {
LOG_ERR("channel input %i is invalid", channel_cfg->input_positive);
@@ -642,6 +667,8 @@
ADS114S0X_REGISTER_INPMUX_MUXP_SET(input_mux, channel_cfg->input_positive);
ADS114S0X_REGISTER_INPMUX_MUXN_SET(input_mux, ADS114S0X_INPUT_SELECTION_AINCOM);
+ pin_selections[0] = channel_cfg->input_positive;
+ pin_selections[1] = ADS114S0X_INPUT_SELECTION_AINCOM;
}
switch (channel_cfg->gain) {
@@ -680,16 +707,95 @@
ADS114S0X_REGISTER_PGA_PGA_EN_SET(gain, 0b01);
}
+ switch (config->idac_current) {
+ case 0:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0000);
+ break;
+ case 10:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0001);
+ break;
+ case 50:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0010);
+ break;
+ case 100:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0011);
+ break;
+ case 250:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0100);
+ break;
+ case 500:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0101);
+ break;
+ case 750:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0110);
+ break;
+ case 1000:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b0111);
+ break;
+ case 1500:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b1000);
+ break;
+ case 2000:
+ ADS114S0X_REGISTER_IDACMAG_IMAG_SET(idac_magnitude, 0b1001);
+ break;
+ default:
+ LOG_ERR("IDAC magnitude %i not supported", config->idac_current);
+ return -EINVAL;
+ }
+
+ if (channel_cfg->current_source_pin_set) {
+ if (channel_cfg->current_source_pin[0] > 0b1111) {
+ LOG_ERR("invalid selection %i for I1MUX",
+ channel_cfg->current_source_pin[0]);
+ return -EINVAL;
+ }
+
+ if (channel_cfg->current_source_pin[1] > 0b1111) {
+ LOG_ERR("invalid selection %i for I2MUX",
+ channel_cfg->current_source_pin[1]);
+ return -EINVAL;
+ }
+
+ ADS114S0X_REGISTER_IDACMUX_I1MUX_SET(idac_mux, channel_cfg->current_source_pin[0]);
+ ADS114S0X_REGISTER_IDACMUX_I2MUX_SET(idac_mux, channel_cfg->current_source_pin[1]);
+ pin_selections[2] = channel_cfg->current_source_pin[0];
+ pin_selections[3] = channel_cfg->current_source_pin[1];
+ pin_selections_size = 4;
+ } else {
+ pin_selections_size = 2;
+ }
+
+ for (size_t i = 0; i < pin_selections_size; ++i) {
+ if (pin_selections[i] > ADS114S0X_INPUT_SELECTION_AINCOM) {
+ continue;
+ }
+
+ for (size_t j = i + 1; j < pin_selections_size; ++j) {
+ if (pin_selections[j] > ADS114S0X_INPUT_SELECTION_AINCOM) {
+ continue;
+ }
+
+ if (pin_selections[i] == pin_selections[j]) {
+ LOG_ERR("pins for inputs and current sources must be different");
+ return -EINVAL;
+ }
+ }
+ }
+
register_addresses[0] = ADS114S0X_REGISTER_INPMUX;
register_addresses[1] = ADS114S0X_REGISTER_PGA;
register_addresses[2] = ADS114S0X_REGISTER_DATARATE;
register_addresses[3] = ADS114S0X_REGISTER_REF;
- BUILD_ASSERT(ARRAY_SIZE(register_addresses) == 4);
+ register_addresses[4] = ADS114S0X_REGISTER_IDACMAG;
+ register_addresses[5] = ADS114S0X_REGISTER_IDACMUX;
+ BUILD_ASSERT(ARRAY_SIZE(register_addresses) == 6);
values[0] = input_mux;
values[1] = gain;
values[2] = data_rate;
values[3] = reference_control;
- BUILD_ASSERT(ARRAY_SIZE(values) == 4);
+ values[4] = idac_magnitude;
+ values[5] = idac_mux;
+ BUILD_ASSERT(ARRAY_SIZE(values) == 6);
result = ads114s0x_write_multiple_registers(&config->bus, register_addresses, values,
ARRAY_SIZE(values));
@@ -1328,6 +1434,7 @@
.gpio_reset = GPIO_DT_SPEC_INST_GET_OR(n, reset_gpios, {0}), \
.gpio_data_ready = GPIO_DT_SPEC_INST_GET(n, drdy_gpios), \
.gpio_start_sync = GPIO_DT_SPEC_INST_GET_OR(n, start_sync_gpios, {0}), \
+ .idac_current = DT_INST_PROP(n, idac_current), \
}; \
static struct ads114s0x_data data_##n; \
DEVICE_DT_INST_DEFINE(n, ads114s0x_init, NULL, &data_##n, &config_##n, POST_KERNEL, \
