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mraa/api/gpio.h
2014-04-30 14:50:01 +01:00

132 lines
3.4 KiB
C

/*
* Author: Thomas Ingleby <thomas.c.ingleby@intel.com>
* Copyright (c) 2014 Intel Corporation.
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be
* included in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
* NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
* LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
* OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
* WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#pragma once
/** @file
*
* This file defines the gpio interface for libmaa
*
*/
#ifdef __cplusplus
extern "C" {
#endif
#include <stdio.h>
#include "maa.h"
/**
* A strucutre representing a gpio pin.
*/
typedef struct {
/*@{*/
int pin; /**< the pin number, as known to the os. */
FILE *value_fp; /**< the file pointer to the value of the gpio */
/*@}*/
} maa_gpio_context;
/**
* GPIO Output modes
*/
typedef enum {
MAA_GPIO_STRONG = 0, /**< Default. Strong high and low */
MAA_GPIO_PULLUP = 1, /**< Resistive High */
MAA_GPIO_PULLDOWN = 2, /**< Resistive Low */
MAA_GPIO_HIZ = 3 /**< High Z State */
} gpio_mode_t;
/**
* GPIO Direction options.
*/
typedef enum {
MAA_GPIO_OUT = 0, /**< Output. A Mode can also be set */
MAA_GPIO_IN = 1 /**< Input. */
} gpio_dir_t;
/** Initialise gpio_context, based on board number
*
* @param pin pin number read from the board, i.e IO3 is 3.
*
* @returns maa_gpio_context based on the IO pin
*/
maa_gpio_context* maa_gpio_init(int pin);
/** Initialise gpio context without any mapping to a pin.
* - For more expert users
*
* @param gpiopin gpio pin as listed in SYSFS
*
* @return gpio context
*/
maa_gpio_context* maa_gpio_init_raw(int gpiopin);
/** Set GPIO Output Mode,
*
* @param dev The GPIO context
* @param mode The GPIO Output Mode.
*
* @return maa result type.
*/
maa_result_t maa_gpio_mode(maa_gpio_context *dev, gpio_mode_t mode);
/** Set GPIO direction
*
* @param dev The GPIO context.
* @param dir The direction of the GPIO.
*
* @return maa result type.
*/
maa_result_t maa_gpio_dir(maa_gpio_context *dev, gpio_dir_t dir);
/** Close the GPIO context
* - Will free the memory for the context.
*
* @param dev the GPIO context
*
* @return maa result type.
*/
maa_result_t maa_gpio_close(maa_gpio_context *dev);
/** Read the GPIO value.
*
* @param dev The GPIO context.
*
* @return the integer value of the GPIO
*/
int maa_gpio_read(maa_gpio_context *dev);
/** Write to the GPIO Value.
*
* @param dev The GPIO context.
* @param value Integer value to write.
*
* @return maa result type
*/
maa_result_t maa_gpio_write(maa_gpio_context *dev, int value);
#ifdef __cplusplus
}
#endif