static mraa_aio_context
mraa_aio_init_internal(mraa_adv_func_t* func_table, int aio)
{
mraa_aio_context dev = calloc(1, sizeof(struct _aio));
if (dev == NULL) {
return NULL;
}
dev->advance_func = func_table;
if (IS_FUNC_DEFINED(dev, aio_init_internal_replace)) {
if (dev->advance_func->aio_init_internal_replace(dev, aio) == MRAA_SUCCESS) {
return dev;
}
free(dev);
return NULL;
}
// Open valid analog input file and get the pointer.
if (MRAA_SUCCESS != aio_get_valid_fp(dev)) {
free(dev);
return NULL;
}
return dev;
}
int
mraa_aio_read(mraa_aio_context dev)
{
if (dev == NULL) {
syslog(LOG_ERR, "aio: read: context is invalid");
return -1;
}
if (IS_FUNC_DEFINED(dev, aio_read_replace)) {
return dev->advance_func->aio_read_replace(dev);
}
char buffer[17];
if (dev->adc_in_fp == -1) {
if (aio_get_valid_fp(dev) != MRAA_SUCCESS) {
syslog(LOG_ERR, "aio: Failed to get to the device");
return -1;
}
}
lseek(dev->adc_in_fp, 0, SEEK_SET);
if (read(dev->adc_in_fp, buffer, sizeof(buffer)) < 1) {
syslog(LOG_ERR, "aio: Failed to read a sensible value");
}
// force NULL termination of string
buffer[16] = '\0';
lseek(dev->adc_in_fp, 0, SEEK_SET);
errno = 0;
char* end;
unsigned int analog_value = (unsigned int) strtoul(buffer, &end, 10);
if (end == &buffer[0]) {
syslog(LOG_ERR, "aio: Value is not a decimal number");
return -1;
} else if (errno != 0) {
syslog(LOG_ERR, "aio: Errno was set");
return -1;
}
/* Adjust the raw analog input reading to supported resolution value*/
if (raw_bits < dev->value_bit) {
analog_value = analog_value << shifter_value;
} else {
analog_value = analog_value >> shifter_value;
}
return analog_value;
}
unsigned int
mraa_aio_read(mraa_aio_context dev)
{
char buffer[17];
unsigned int shifter_value = 0;
if (dev->adc_in_fp == -1) {
if (aio_get_valid_fp(dev) != MRAA_SUCCESS) {
syslog(LOG_ERR, "aio: Failed to get to the device");
return 0;
}
}
lseek(dev->adc_in_fp, 0, SEEK_SET);
if (read(dev->adc_in_fp, buffer, sizeof(buffer)) < 1) {
syslog(LOG_ERR, "aio: Failed to read a sensible value");
}
// force NULL termination of string
buffer[16] = '\0';
lseek(dev->adc_in_fp, 0, SEEK_SET);
errno = 0;
char* end;
unsigned int analog_value = (unsigned int) strtoul(buffer, &end, 10);
if (end == &buffer[0]) {
syslog(LOG_ERR, "aio: Value is not a decimal number");
} else if (errno != 0) {
syslog(LOG_ERR, "aio: Errno was set");
}
if (dev->value_bit != raw_bits) {
/* Adjust the raw analog input reading to supported resolution value*/
if (raw_bits > dev->value_bit) {
shifter_value = raw_bits - dev->value_bit;
analog_value = analog_value >> shifter_value;
} else {
mraa_aio_context
mraa_aio_init(unsigned int aio)
{
if (plat == NULL) {
syslog(LOG_ERR, "aio: Platform not initialised");
return NULL;
}
if (mraa_is_sub_platform_id(aio)) {
syslog(LOG_NOTICE, "aio: Using sub platform is not supported");
return NULL;
}
// Create ADC device connected to specified channel
mraa_aio_context dev = mraa_aio_init_internal(plat->adv_func);
if (dev == NULL) {
syslog(LOG_ERR, "aio: Insufficient memory for specified input channel %d", aio);
return NULL;
}
int pin = aio + plat->gpio_count;
dev->channel = plat->pins[pin].aio.pinmap;
dev->value_bit = DEFAULT_BITS;
if (IS_FUNC_DEFINED(dev, aio_init_pre)) {
mraa_result_t pre_ret = (dev->advance_func->aio_init_pre(aio));
if (pre_ret != MRAA_SUCCESS) {
free(dev);
return NULL;
}
}
if (aio > plat->aio_count) {
syslog(LOG_ERR, "aio: requested channel out of range");
free(dev);
return NULL;
}
if (plat->pins[pin].capabilites.aio != 1) {
syslog(LOG_ERR, "aio: pin uncapable of aio");
free(dev);
return NULL;
}
if (plat->pins[pin].aio.mux_total > 0) {
if (mraa_setup_mux_mapped(plat->pins[pin].aio) != MRAA_SUCCESS) {
free(dev);
syslog(LOG_ERR, "aio: unable to setup multiplexers for pin");
return NULL;
}
}
// Open valid analog input file and get the pointer.
if (MRAA_SUCCESS != aio_get_valid_fp(dev)) {
free(dev);
return NULL;
}
raw_bits = mraa_adc_raw_bits();
if (IS_FUNC_DEFINED(dev, aio_init_post)) {
mraa_result_t ret = dev->advance_func->aio_init_post(dev);
if (ret != MRAA_SUCCESS) {
free(dev);
return NULL;
}
}
return dev;
}
