feat(adc): use const pointer in io_to_channel APIs

components/esp_adc/adc_common.c

@@ -59,7 +59,7 @@ void adc_apb_periph_free(void)
 /*---------------------------------------------------------------
             ADC IOs
 ---------------------------------------------------------------*/
-esp_err_t adc_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *channel)
+esp_err_t adc_io_to_channel(int io_num, adc_unit_t * const unit_id, adc_channel_t * const channel)
 {
     ESP_RETURN_ON_FALSE(GPIO_IS_VALID_GPIO(io_num), ESP_ERR_INVALID_ARG, TAG, "invalid gpio number");
     ESP_RETURN_ON_FALSE(unit_id && channel, ESP_ERR_INVALID_ARG, TAG, "invalid argument: null pointer");
@@ -77,7 +77,7 @@ esp_err_t adc_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *chan
     return (found) ? ESP_OK : ESP_ERR_NOT_FOUND;
 }
 
-esp_err_t adc_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int *io_num)
+esp_err_t adc_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int * const io_num)
 {
     ESP_RETURN_ON_FALSE(unit_id < SOC_ADC_PERIPH_NUM, ESP_ERR_INVALID_ARG, TAG, "invalid unit");
     ESP_RETURN_ON_FALSE(channel < SOC_ADC_CHANNEL_NUM(unit_id), ESP_ERR_INVALID_ARG, TAG, "invalid channel");

components/esp_adc/adc_continuous.c

@@ -613,12 +613,12 @@ esp_err_t adc_continuous_register_event_callbacks(adc_continuous_handle_t handle
     return ESP_OK;
 }
 
-esp_err_t adc_continuous_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *channel)
+esp_err_t adc_continuous_io_to_channel(int io_num, adc_unit_t * const unit_id, adc_channel_t * const channel)
 {
     return adc_io_to_channel(io_num, unit_id, channel);
 }
 
-esp_err_t adc_continuous_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int *io_num)
+esp_err_t adc_continuous_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int * const io_num)
 {
     return adc_channel_to_io(unit_id, channel, io_num);
 }

components/esp_adc/adc_oneshot.c

@@ -62,12 +62,12 @@ static bool s_adc_unit_free(adc_unit_t unit);
 static esp_err_t s_adc_io_init(adc_unit_t unit, adc_channel_t channel);
 
 
-esp_err_t adc_oneshot_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *channel)
+esp_err_t adc_oneshot_io_to_channel(int io_num, adc_unit_t * const unit_id, adc_channel_t * const channel)
 {
     return adc_io_to_channel(io_num, unit_id, channel);
 }
 
-esp_err_t adc_oneshot_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int *io_num)
+esp_err_t adc_oneshot_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int * const io_num)
 {
     return adc_channel_to_io(unit_id, channel, io_num);
 }

components/esp_adc/include/esp_adc/adc_continuous.h

@@ -211,7 +211,7 @@ esp_err_t adc_continuous_deinit(adc_continuous_handle_t handle);
  *        - ESP_ERR_INVALID_ARG: Invalid argument
  *        - ESP_ERR_NOT_FOUND:   The IO is not a valid ADC pad
  */
-esp_err_t adc_continuous_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *channel);
+esp_err_t adc_continuous_io_to_channel(int io_num, adc_unit_t * const unit_id, adc_channel_t * const channel);
 
 /**
  * @brief Get GPIO number from the given ADC channel
@@ -224,7 +224,7 @@ esp_err_t adc_continuous_io_to_channel(int io_num, adc_unit_t *unit_id, adc_chan
  *       - ESP_OK:              On success
  *       - ESP_ERR_INVALID_ARG: Invalid argument
  */
-esp_err_t adc_continuous_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int *io_num);
+esp_err_t adc_continuous_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int * const io_num);
 
 
 #ifdef __cplusplus

components/esp_adc/include/esp_adc/adc_oneshot.h

@@ -114,7 +114,7 @@ esp_err_t adc_oneshot_del_unit(adc_oneshot_unit_handle_t handle);
  *        - ESP_ERR_INVALID_ARG: Invalid argument
  *        - ESP_ERR_NOT_FOUND:   The IO is not a valid ADC pad
  */
-esp_err_t adc_oneshot_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *channel);
+esp_err_t adc_oneshot_io_to_channel(int io_num, adc_unit_t * const unit_id, adc_channel_t * const channel);
 
 /**
  * @brief Get GPIO number from the given ADC channel
@@ -127,7 +127,7 @@ esp_err_t adc_oneshot_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel
  *       - ESP_OK:              On success
  *       - ESP_ERR_INVALID_ARG: Invalid argument
  */
-esp_err_t adc_oneshot_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int *io_num);
+esp_err_t adc_oneshot_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int * const io_num);
 
 /**
  * @brief Convenience function to get ADC calibrated result

components/esp_adc/include/esp_private/adc_private.h

@@ -49,7 +49,7 @@ void adc_apb_periph_free(void);
  *        - ESP_ERR_INVALID_ARG: Invalid argument
  *        - ESP_ERR_NOT_FOUND:   The IO is not a valid ADC pad
  */
-esp_err_t adc_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *channel);
+esp_err_t adc_io_to_channel(int io_num, adc_unit_t * const unit_id, adc_channel_t * const channel);
 
 /**
  * @brief Get GPIO number from the given ADC channel
@@ -62,7 +62,7 @@ esp_err_t adc_io_to_channel(int io_num, adc_unit_t *unit_id, adc_channel_t *chan
  *       - ESP_OK:              On success
  *       - ESP_ERR_INVALID_ARG: Invalid argument
  */
-esp_err_t adc_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int *io_num);
+esp_err_t adc_channel_to_io(adc_unit_t unit_id, adc_channel_t channel, int * const io_num);
 
 
 /*---------------------------------------------------------------