static ssize_t sht15_show_temp(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
struct sht15_data *data = dev_get_drvdata(dev);
/* Technically no need to read humidity as well */
ret = sht15_update_vals(data);
return ret ? ret : sprintf(buf, "%d\n",
sht15_calc_temp(data));
}
static ssize_t sht15_show_temp(struct device *dev,
struct device_attribute *attr,
char *buf)
{
int ret;
struct sht15_data *data = dev_get_drvdata(dev);
ret = sht15_update_vals(data);
return ret ? ret : sprintf(buf, "%d\n",
sht15_calc_temp(data));
}
/**
* sht15_calc_humid() - using last temperature convert raw to humid
* @data: device state
*
* This is the temperature compensated version as per section 4.2 of
* the data sheet.
**/
static inline int sht15_calc_humid(struct sht15_data *data)
{
int RHlinear; /* milli percent */
int temp = sht15_calc_temp(data);
const int c1 = -4;
const int c2 = 40500; /* x 10 ^ -6 */
const int c3 = -28; /* x 10 ^ -7 */
RHlinear = c1*1000
+ c2 * data->val_humid/1000
+ (data->val_humid * data->val_humid * c3) / 10000;
return (temp - 25000) * (10000 + 80 * data->val_humid)
/ 1000000 + RHlinear;
}
static inline int sht15_calc_humid(struct sht15_data *data)
{
int RHlinear;
int temp = sht15_calc_temp(data);
const int c1 = -4;
const int c2 = 40500;
const int c3 = -2800;
RHlinear = c1*1000
+ c2 * data->val_humid/1000
+ (data->val_humid * data->val_humid * c3)/1000000;
return (temp - 25000) * (10000 + 80 * data->val_humid)
/ 1000000 + RHlinear;
}
