--- /dev/null
+/*
+ * 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);
--- /dev/null
+/*
+ * 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.
+ */
+
+#include <unistd.h>
+
+#include "aio.h"
+
+int main ()
+{
+ maa_aio_context* adc_a0;
+ unsigned int adc_value = 0;
+ int i = 0;
+
+ adc_a0 = maa_aio_init(A0);
+ if (adc_a0 == NULL) {
+ return 1;
+ }
+
+ for(i = 0; i < 10; i++) {
+ adc_value = maa_aio_read_u16(adc_a0);
+ fprintf(stdout, "ADC A0 read %X\n", adc_value);
+ }
+
+ maa_aio_close(adc_a0);
+
+ return MAA_SUCCESS;
+}
--- /dev/null
+/*
+ * 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.
+ */
+
+#include <stdlib.h>
+
+#include "aio.h"
+
+static maa_result_t aio_get_valid_fp(maa_aio_context* dev)
+{
+ char file_path[64]= "";
+
+ //Open file Analog device input channel raw voltage file for reading.
+ snprintf(file_path, 64, "/sys/bus/iio/devices/iio:device0/in_voltage%d_raw",
+ dev->channel );
+
+ if (NULL == (dev->adc_in_fp = fopen(file_path, "r"))) {
+ fprintf(stderr, "Failed to open Analog input raw file %s for "
+ "reading!\n", file_path); return( MAA_ERROR_INVALID_RESOURCE);
+ }
+
+ return MAA_SUCCESS;
+}
+
+/** Configure multiplexer for Analog Input
+ *
+ * @param aio_channel = Analog input channel to read
+ *
+ * @return maa_result_t - result type.
+ *
+ */
+static maa_result_t maa_aio_set_mux(unsigned int aio_channel)
+{
+ maa_result_t result;
+ maa_gpio_context* aio_gate;
+
+ //Initialise VINx multiplexer gate pins
+ aio_gate = maa_gpio_init(adc_gate_pins[aio_channel]);
+
+ if (NULL == aio_gate) {
+ fprintf(stderr, "Failed to initialise first gate pin %d for ADC "
+ "channel %d !\n", adc_gate_pins[aio_channel], aio_channel);
+ return MAA_ERROR_INVALID_RESOURCE;
+ }
+
+ //Set direction to output for the ADC input gate
+ result = maa_gpio_dir(aio_gate, MAA_GPIO_OUT);
+
+ if (MAA_SUCCESS == result) {
+ // Write gate configuration output value
+ result = maa_gpio_write(aio_gate, 0);
+
+ if (MAA_SUCCESS == result) {
+ //For A4 and A5 Analog common gate pin should be high for the
+ // Galileo board revision D
+ if (A4 == aio_channel || A5 == aio_channel) {
+ aio_gate = maa_gpio_init(ADC_COMMON_GATE_A4_A5);
+
+ //Set direction to output for the gate
+ if (NULL == aio_gate) {
+ fprintf(stderr, "Failed to initialise second gate pin %d "
+ "for ADC channel %d !\n", ADC_COMMON_GATE_A4_A5,
+ aio_channel);
+ return(MAA_ERROR_INVALID_RESOURCE);
+ }
+
+ result = maa_gpio_dir(aio_gate, MAA_GPIO_OUT);
+ if (MAA_SUCCESS == result)
+ // Write gate configuration output value
+ result = maa_gpio_write(aio_gate, 1);
+ }
+ }
+ }
+
+ if (NULL != aio_gate)
+ free(aio_gate);
+
+ return (result);
+}
+
+/** Initialise an Analog input, connected to the specified channel
+ *
+ * @param aio_channel Analog input channel to read
+ *
+ * @returns pointer to maa_aio_context structure after initialisation of
+ * Analog input pin connected to the device successfully, else returns NULL.
+ */
+maa_aio_context* maa_aio_init(unsigned int aio_channel)
+{
+ maa_aio_context* dev;
+
+ // Validate input pins 0-5
+ if (aio_channel > TOTAL_ANALOG_INPUTS_ON_BOARD) {
+ fprintf(stderr, "Invalid Analog input channel %d specified!\n",
+ aio_channel);
+ return NULL;
+ }
+
+ //Set-up multiplexer for the Analog input channel
+ if (MAA_SUCCESS != maa_aio_set_mux(aio_channel)) {
+ fprintf(stderr, "Failed to set-up Analog input channel %d "
+ "multiplexer!\n", aio_channel); return NULL;
+ }
+
+ //Create ADC device connected to specified channel
+ dev = (maa_aio_context*) malloc(sizeof(maa_aio_context));
+ if (NULL == dev) {
+ fprintf(stderr, "Insufficient memory for specified Analog input channel "
+ "%d !\n", aio_channel);
+ return NULL;
+ }
+ dev->channel = aio_channel;
+
+ //Open valid analog input file and get the pointer.
+ if (MAA_SUCCESS != aio_get_valid_fp(dev)) {
+ free(dev);
+ return NULL;
+ }
+
+ return dev;
+}
+
+/** Read the input voltage, represented as an unsigned short in the range [0x0,
+ * 0xFFFF]
+ *
+ * @param pointer to maa_aio_context structure initialised by
+ * maa_aio_init()
+ *
+ * @returns
+ * 16-bit unsigned int representing the current input voltage, normalised to
+ * a 16-bit value
+ */
+unsigned int maa_aio_read_u16(maa_aio_context* dev)
+{
+ char buffer[16] = "";
+ unsigned int raw_value=0;
+ unsigned int analog_value=0;
+ unsigned int shifter_value=0;
+
+ if (NULL == dev->adc_in_fp) {
+ aio_get_valid_fp(dev);
+ }
+
+ fseek(dev->adc_in_fp, SEEK_SET, 0);
+ fread(buffer, sizeof(buffer), 1, dev->adc_in_fp);
+ fseek(dev->adc_in_fp, SEEK_SET, 0);
+
+ raw_value = atoi(buffer);
+
+ /* Adjust the raw analog input reading to supported resolution value*/
+ if (ADC_RAW_RESOLUTION_BITS == ADC_SUPPORTED_RESOLUTION_BITS) {
+ analog_value = raw_value;
+ }
+ else {
+ if (ADC_RAW_RESOLUTION_BITS > ADC_SUPPORTED_RESOLUTION_BITS) {
+ shifter_value = ADC_RAW_RESOLUTION_BITS - ADC_SUPPORTED_RESOLUTION_BITS;
+ analog_value = raw_value >> shifter_value;
+ } else {
+ shifter_value = ADC_SUPPORTED_RESOLUTION_BITS - ADC_RAW_RESOLUTION_BITS;
+ analog_value = raw_value << shifter_value;
+ }
+ }
+
+ return analog_value;
+}
+
+/** Close the analog input and free context memory
+ *
+ * @param dev - the analog input context
+ *
+ * @return maa result type.
+ */
+maa_result_t maa_aio_close(maa_aio_context* dev)
+{
+ if (NULL != dev)
+ free(dev);
+
+ return(MAA_SUCCESS);
+}
projects / contrib / mraa.git / commitdiff