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aio: add initial analog input support

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Signed-off-by: Nandkishor Sonar <nandkishor.sonar@intel.com>
Reviewed-by: Brendan Le Foll <brendan.le.foll@intel.com>
This commit is contained in:
Nandkishor Sonar
2014-05-01 16:36:11 +01:00
committed by Brendan Le Foll
parent 8c016318a6
commit 207c54a5e7
5 changed files with 333 additions and 0 deletions
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api/aio.h Normal file
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/*
* Author: Nandkishor Sonar
* 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
#include <stdio.h>
#include <fcntl.h>
#include "maa.h"
#include "gpio.h"
#define TOTAL_ANALOG_INPUTS_ON_BOARD (6)
static const unsigned int A0 = 0;
static const unsigned int A1 = 1;
static const unsigned int A2 = 2;
static const unsigned int A3 = 3;
static const unsigned int A4 = 4;
static const unsigned int A5 = 5;
#define ADC_RAW_RESOLUTION_BITS (12)
#define ADC_SUPPORTED_RESOLUTION_BITS (10)
#define ADC_COMMON_GATE_A4_A5 (29)
static const unsigned int
adc_gate_pins[TOTAL_ANALOG_INPUTS_ON_BOARD] = {37, 36, 23, 22, 21, 20};
typedef struct {
unsigned int channel;
FILE *adc_in_fp;
} maa_aio_context;
/** Initialise an Analog input device, connected to the specified pin
*
* @param aio_channel channel number to read ADC inputs
*
* @returns pointer to maa_aio_context structure after initialisation of Analog
* input pin successfully, else returns null.
*/
maa_aio_context* maa_aio_init(unsigned int aio_channel);
/** Read the input voltage, represented as an unsigned short in the range [0x0,
* 0xFFFF]
*
* @param dev - pointer to maa_aio_context structure initialised by
* maa_aio_init()
*
* @returns 16-bit unsigned integer representing the current input voltage,
* normalised to a 16-bit value
*/
unsigned int maa_aio_read_u16(maa_aio_context* dev);
/** Close the analog input context
* - Will free the memory for the context.
*
* @param dev - pointer to maa_aio_context structure initialised by
* maa_aio_init()
*
* @return maa_result_t - result type.
*/
maa_result_t maa_aio_close(maa_aio_context* dev);