esp-idf/components/esp_driver_rmt/include/driver/rmt_common.h

/*
 * SPDX-FileCopyrightText: 2015-2022 Espressif Systems (Shanghai) CO LTD
 *
 * SPDX-License-Identifier: Apache-2.0
 */

#pragma once

#include <stdint.h>
#include "esp_err.h"
#include "driver/rmt_types.h"

#ifdef __cplusplus
extern "C" {
#endif

/**
 * @brief RMT carrier wave configuration (for either modulation or demodulation)
 */
typedef struct {
    uint32_t frequency_hz; /*!< Carrier wave frequency, in Hz, 0 means disabling the carrier */
    float duty_cycle;      /*!< Carrier wave duty cycle (0~100%) */
    struct {
        uint32_t polarity_active_low: 1; /*!< Specify the polarity of carrier, by default it's modulated to base signal's high level */
        uint32_t always_on: 1;           /*!< If set, the carrier can always exist even there's not transfer undergoing */
    } flags;                             /*!< Carrier config flags */
} rmt_carrier_config_t;

/**
 * @brief Delete an RMT channel
 *
 * @param[in] channel RMT generic channel that created by `rmt_new_tx_channel()` or `rmt_new_rx_channel()`
 * @return
 *      - ESP_OK: Delete RMT channel successfully
 *      - ESP_ERR_INVALID_ARG: Delete RMT channel failed because of invalid argument
 *      - ESP_ERR_INVALID_STATE: Delete RMT channel failed because it is still in working
 *      - ESP_FAIL: Delete RMT channel failed because of other error
 */
esp_err_t rmt_del_channel(rmt_channel_handle_t channel);

/**
 * @brief Apply modulation feature for TX channel or demodulation feature for RX channel
 *
 * @param[in] channel RMT generic channel that created by `rmt_new_tx_channel()` or `rmt_new_rx_channel()`
 * @param[in] config Carrier configuration. Specially, a NULL config means to disable the carrier modulation or demodulation feature
 * @return
 *      - ESP_OK: Apply carrier configuration successfully
 *      - ESP_ERR_INVALID_ARG: Apply carrier configuration failed because of invalid argument
 *      - ESP_FAIL: Apply carrier configuration failed because of other error
 */
esp_err_t rmt_apply_carrier(rmt_channel_handle_t channel, const rmt_carrier_config_t *config);

/**
 * @brief Enable the RMT channel
 *
 * @note This function will acquire a PM lock that might be installed during channel allocation
 *
 * @param[in] channel RMT generic channel that created by `rmt_new_tx_channel()` or `rmt_new_rx_channel()`
 * @return
 *      - ESP_OK: Enable RMT channel successfully
 *      - ESP_ERR_INVALID_ARG: Enable RMT channel failed because of invalid argument
 *      - ESP_ERR_INVALID_STATE: Enable RMT channel failed because it's enabled already
 *      - ESP_FAIL: Enable RMT channel failed because of other error
 */
esp_err_t rmt_enable(rmt_channel_handle_t channel);

/**
 * @brief Disable the RMT channel
 *
 * @note This function will release a PM lock that might be installed during channel allocation
 *
 * @param[in] channel RMT generic channel that created by `rmt_new_tx_channel()` or `rmt_new_rx_channel()`
 * @return
 *      - ESP_OK: Disable RMT channel successfully
 *      - ESP_ERR_INVALID_ARG: Disable RMT channel failed because of invalid argument
 *      - ESP_ERR_INVALID_STATE: Disable RMT channel failed because it's not enabled yet
 *      - ESP_FAIL: Disable RMT channel failed because of other error
 */
esp_err_t rmt_disable(rmt_channel_handle_t channel);

#ifdef __cplusplus
}
#endif