esp-idf/components/esp_rom/include/esp_rom_gpio.h

// Copyright 2010-2020 Espressif Systems (Shanghai) PTE LTD
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#pragma once

#ifdef __cplusplus
extern "C" {
#endif

#include <stdint.h>
#include <stdbool.h>
#include "soc/gpio_pins.h"  //for GPIO_MATRIX_CONST_ONE_INPUT, GPIO_MATRIX_CONST_ZERO_INPUT

/**
 * @brief Configure IO Pad as General Purpose IO,
 *        so that it can be connected to internal Matrix,
 *        then combined with one or more peripheral signals.
 *
 * @param iopad_num IO Pad number
 */
void esp_rom_gpio_pad_select_gpio(uint32_t iopad_num);

/**
 * @brief Enable internal pull up, and disable internal pull down.
 *
 * @param iopad_num IO Pad number
 */
void esp_rom_gpio_pad_pullup_only(uint32_t iopad_num);

/**
 * @brief Unhold the IO Pad.
 * @note When the Pad is set to hold, the state is latched at that moment and won't get changed.
 *
 * @param iopad_num IP Pad number
 */
void esp_rom_gpio_pad_unhold(uint32_t gpio_num);

/**
 * @brief Set IO Pad current drive capability.
 *
 * @param iopad_num IO Pad number
 * @param drv Numeric to indicate the capability of current drive
 *      - 0: 5mA
 *      - 1: 10mA
 *      - 2: 20mA
 *      - 3: 40mA
 */
void esp_rom_gpio_pad_set_drv(uint32_t iopad_num, uint32_t drv);

/**
 * @brief Combine a GPIO input with a peripheral signal, which tagged as input attribute.
 *
 * @note There's no limitation on the number of signals that a GPIO can combine with.
 *
 * @param gpio_num GPIO number, especially, `GPIO_MATRIX_CONST_ZERO_INPUT` means connect logic 0 to signal
 *                                          `GPIO_MATRIX_CONST_ONE_INPUT` means connect logic 1 to signal
 * @param signal_idx Peripheral signal index (tagged as input attribute)
 * @param inv  Whether the GPIO input to be inverted or not
 */
void esp_rom_gpio_connect_in_signal(uint32_t gpio_num, uint32_t signal_idx, bool inv);

/**
 * @brief Combine a peripheral signal which tagged as output attribute with a GPIO.
 *
 * @note There's no limitation on the number of signals that a GPIO can combine with.
 *
 * @param gpio_num GPIO number
 * @param signal_idx Peripheral signal index (tagged as output attribute)
 * @param out_inv Whether to signal to be inverted or not
 * @param oen_inv Whether the output enable control is inverted or not
 */
void esp_rom_gpio_connect_out_signal(uint32_t gpio_num, uint32_t signal_idx, bool out_inv, bool oen_inv);

#ifdef __cplusplus
}
#endif