mraa_result_t
mraa_gpio_write(mraa_gpio_context dev, int value)
{
if (dev == NULL)
return MRAA_ERROR_INVALID_HANDLE;
if (dev->mmap_write != NULL)
return dev->mmap_write(dev,value);
if (advance_func->gpio_write_pre != NULL) {
mraa_result_t pre_ret = (advance_func->gpio_write_pre(dev,value));
if(pre_ret != MRAA_SUCCESS)
return pre_ret;
}
if (dev->value_fp == -1) {
if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
return MRAA_ERROR_INVALID_RESOURCE;
}
}
if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
return MRAA_ERROR_INVALID_RESOURCE;
}
char bu[MAX_SIZE];
int length = snprintf(bu, sizeof(bu), "%d", value);
if (write(dev->value_fp, bu, length*sizeof(char)) == -1) {
return MRAA_ERROR_INVALID_HANDLE;
}
if (advance_func->gpio_write_post != NULL)
return advance_func->gpio_write_post(dev,value);
return MRAA_SUCCESS;
}
int
mraa_gpio_read(mraa_gpio_context dev)
{
if (dev == NULL)
return -1;
if (dev->mmap_read != NULL)
return dev->mmap_read(dev);
if (dev->value_fp == -1) {
if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
syslog(LOG_ERR, "gpio: Failed to get value file pointer");
return -1;
}
}
else {
// if value_fp is new this is pointless
lseek(dev->value_fp, 0, SEEK_SET);
}
char bu[2];
if (read(dev->value_fp, bu, 2*sizeof(char)) != 2) {
syslog(LOG_ERR, "gpio: Failed to read a sensible value from sysfs");
return -1;
}
lseek(dev->value_fp, 0, SEEK_SET);
return (int) strtol(bu, NULL, 10);
}
int
mraa_gpio_read(mraa_gpio_context dev)
{
if (dev == NULL) {
syslog(LOG_ERR, "gpio: read: context is invalid");
return -1;
}
if (IS_FUNC_DEFINED(dev, gpio_read_replace))
return dev->advance_func->gpio_read_replace(dev);
if (dev->mmap_read != NULL)
return dev->mmap_read(dev);
if (dev->value_fp == -1) {
if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
return -1;
}
} else {
// if value_fp is new this is pointless
lseek(dev->value_fp, 0, SEEK_SET);
}
char bu[2];
if (read(dev->value_fp, bu, 2 * sizeof(char)) != 2) {
syslog(LOG_ERR, "gpio%i: read: Failed to read a sensible value from sysfs: %s", dev->pin, strerror(errno));
return -1;
}
lseek(dev->value_fp, 0, SEEK_SET);
return (int) strtol(bu, NULL, 10);
}
mraa_result_t
mraa_gpio_write(mraa_gpio_context dev, int value)
{
if (dev == NULL) {
syslog(LOG_ERR, "gpio: write: context is invalid");
return MRAA_ERROR_INVALID_HANDLE;
}
if (dev->mmap_write != NULL)
return dev->mmap_write(dev, value);
if (IS_FUNC_DEFINED(dev, gpio_write_pre)) {
mraa_result_t pre_ret = (dev->advance_func->gpio_write_pre(dev, value));
if (pre_ret != MRAA_SUCCESS)
return pre_ret;
}
if (IS_FUNC_DEFINED(dev, gpio_write_replace)) {
return dev->advance_func->gpio_write_replace(dev, value);
}
if (dev->value_fp == -1) {
if (mraa_gpio_get_valfp(dev) != MRAA_SUCCESS) {
return MRAA_ERROR_INVALID_RESOURCE;
}
}
if (lseek(dev->value_fp, 0, SEEK_SET) == -1) {
syslog(LOG_ERR, "gpio%i: write: Failed to lseek 'value': %s", dev->pin, strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
char bu[MAX_SIZE];
int length = snprintf(bu, sizeof(bu), "%d", value);
if (write(dev->value_fp, bu, length * sizeof(char)) == -1) {
syslog(LOG_ERR, "gpio%i: write: Failed to write to 'value': %s", dev->pin, strerror(errno));
return MRAA_ERROR_UNSPECIFIED;
}
if (IS_FUNC_DEFINED(dev, gpio_write_post))
return dev->advance_func->gpio_write_post(dev, value);
return MRAA_SUCCESS;
}