int i2c_parse(FAR struct i2ctool_s *i2ctool, int argc, char *argv[])
{
FAR char *newargs[MAX_ARGUMENTS+2];
FAR char *cmd;
int nargs;
int index;
/* Parse out the command, skipping the first argument (the program name)*/
index = 1;
cmd = i2c_argument(i2ctool, argc, argv, &index);
/* Check if any command was provided */
if (!cmd)
{
/* An empty line is not an error and an unprocessed command cannot
* generate an error, but neither should they change the last
* command status.
*/
return i2ccmd_help(i2ctool, 0, NULL);
}
/* Parse all of the arguments following the command name. */
newargs[0] = cmd;
for (nargs = 1; nargs <= MAX_ARGUMENTS; nargs++)
{
newargs[nargs] = i2c_argument(i2ctool, argc, argv, &index);
if (!newargs[nargs])
{
break;
}
}
newargs[nargs] = NULL;
/* Then execute the command */
return i2c_execute(i2ctool, nargs, newargs);
}
// read the lm75 temperature sensor
// lm75 has a two-byte temperature output. The first byte is the temperature,
// and the second byte's highest bit is a half-degree adder
static void
lm75_read(struct locl_sensor *sensor)
{
i2c_op *ops[2];
i2c_op read_lm75;
char buf[2];
int rc;
bool fault = false;
const YamlDevice *device = yaml_find_device(
yaml_handle,
sensor->subsystem->name,
sensor->yaml_sensor->device);
VLOG_DBG("reading sensor '%s'", sensor->yaml_sensor->device);
if (sensor->test_temp != -1) {
VLOG_DBG("Test temperature override set to %d", sensor->test_temp);
sensor->status = SENSOR_STATUS_NORMAL;
sensor->temp = sensor->test_temp;
return;
}
memset(buf, 0xFF, sizeof(buf));
memset(&read_lm75, 0, sizeof(read_lm75));
ops[0] = &read_lm75;
ops[1] = NULL;
read_lm75.direction = READ;
read_lm75.device = sensor->yaml_sensor->device;
read_lm75.byte_count = 2;
read_lm75.data = (unsigned char *)buf;
read_lm75.register_address = 0;
rc = i2c_execute(yaml_handle, sensor->subsystem->name, device, ops);
if (0 != rc) {
fault = true;
}
if (true == fault) {
// if we've hit the retry limit, mark it as failed
if (sensor->fault_count > MAX_FAIL_RETRY) {
sensor->status = SENSOR_STATUS_FAILED;
}
// otherwise, don't change the temp or status, but increment the retry
// count
sensor->fault_count++;
return;
}
// if we succeeded in reading the temp, then clear the retry count
sensor->fault_count = 0;
if (sensor->status == SENSOR_STATUS_FAILED) {
// we need to kick this sensor back into a working state
sensor->status = SENSOR_STATUS_NORMAL;
}
// convert to milidegrees (C)
sensor->temp = buf[0] * MILI_DEGREES;
// high bit in second byte is half-degree indicator
if (buf[1] < 0) {
// half-degree in milidegrees
sensor->temp += 500;
}
VLOG_DBG("%s: %4.1fc", sensor->yaml_sensor->device, ((float)sensor->temp)/MILI_DEGREES_FLOAT);
}