drivers: adc: adc_emul: implement raw func set function in adc_emul

allow setting a function as generator of raw adc values in adc_emul

Signed-off-by: Nathan Olff <[email protected]>

Author: nono313

drivers/adc/adc_emul.c

@@ -32,6 +32,7 @@ enum adc_emul_input_source {
 	ADC_EMUL_CONST_VALUE,
 	ADC_EMUL_CUSTOM_FUNC,
 	ADC_EMUL_CONST_RAW_VALUE,
+	ADC_EMUL_CUSTOM_FUNC_RAW_VALUE,
 };
 
 /**
@@ -40,7 +41,7 @@ enum adc_emul_input_source {
  * This structure contains configuration of one channel of emulated ADC.
  */
 struct adc_emul_chan_cfg {
-	/** Pointer to function used to obtain input mV */
+	/** Pointer to function used to obtain input mV or raw input value */
 	adc_emul_value_func func;
 	/** Pointer to data that are passed to @a func on call */
 	void *func_data;
@@ -176,6 +177,31 @@ int adc_emul_value_func_set(const struct device *dev, unsigned int chan, adc_emu
 	return 0;
 }
 
+int adc_emul_raw_value_func_set(const struct device *dev, unsigned int chan,
+				adc_emul_value_func func, void *func_data)
+{
+	const struct adc_emul_config *config = dev->config;
+	struct adc_emul_data *data = dev->data;
+	struct adc_emul_chan_cfg *chan_cfg;
+
+	if (chan >= config->num_channels) {
+		LOG_ERR("unsupported channel %d", chan);
+		return -EINVAL;
+	}
+
+	chan_cfg = &data->chan_cfg[chan];
+
+	k_mutex_lock(&data->cfg_mtx, K_FOREVER);
+
+	chan_cfg->func = func;
+	chan_cfg->func_data = func_data;
+	chan_cfg->input = ADC_EMUL_CUSTOM_FUNC_RAW_VALUE;
+
+	k_mutex_unlock(&data->cfg_mtx);
+
+	return 0;
+}
+
 int adc_emul_ref_voltage_set(const struct device *dev, enum adc_reference ref,
 			     uint16_t value)
 {
@@ -456,6 +482,15 @@ static int adc_emul_get_chan_value(struct adc_emul_data *data,
 		temp = chan_cfg->const_value;
 		goto check_bound_and_out;
 
+	case ADC_EMUL_CUSTOM_FUNC_RAW_VALUE:
+		err = chan_cfg->func(data->dev, chan, chan_cfg->func_data, &input_mV);
+		if (err) {
+			LOG_ERR("failed to read channel %d (err %d)", chan, err);
+			goto out;
+		}
+		temp = input_mV;
+		goto check_bound_and_out;
+
 	default:
 		LOG_ERR("unknown input source %d", chan_cfg->input);
 		err = -EINVAL;

include/zephyr/drivers/adc/adc_emul.h

@@ -99,6 +99,21 @@ int adc_emul_const_raw_value_set(const struct device *dev, unsigned int chan, ui
 int adc_emul_value_func_set(const struct device *dev, unsigned int chan,
 			    adc_emul_value_func func, void *data);
 
+/**
+ * @brief Set function used to obtain voltage for raw input value of emulated
+ *        ADC @p chan
+ *
+ * @param dev The emulated ADC device
+ * @param chan The channel of ADC to which @p func is assigned
+ * @param func New function to assign to @p chan
+ * @param data Pointer to data passed to @p func on call
+ *
+ * @return 0 on success
+ * @return -EINVAL if an invalid argument is provided
+ */
+int adc_emul_raw_value_func_set(const struct device *dev, unsigned int chan,
+				adc_emul_value_func func, void *data);
+
 /**
  * @brief Set reference voltage
  *