diff options
| -rw-r--r-- | drivers/hwmon/sht4x.c | 95 |
1 files changed, 45 insertions, 50 deletions
diff --git a/drivers/hwmon/sht4x.c b/drivers/hwmon/sht4x.c index 1dc51ee2a72b..09c2a0b06444 100644 --- a/drivers/hwmon/sht4x.c +++ b/drivers/hwmon/sht4x.c @@ -67,7 +67,7 @@ struct sht4x_data { /** * sht4x_read_values() - read and parse the raw data from the SHT4X * @sht4x_data: the struct sht4x_data to use for the lock - * Return: 0 if succesfull, 1 if not + * Return: 0 if successful, -ERRNO if not */ static int sht4x_read_values(struct sht4x_data *data) { @@ -75,51 +75,53 @@ static int sht4x_read_values(struct sht4x_data *data) u16 t_ticks, rh_ticks; unsigned long next_update; struct i2c_client *client = data->client; - u8 crc, raw_data[SHT4X_RESPONSE_LENGTH], - cmd[] = {SHT4X_CMD_MEASURE_HPM}; + u8 crc; + u8 cmd[SHT4X_CMD_LEN] = {SHT4X_CMD_MEASURE_HPM}; + u8 raw_data[SHT4X_RESPONSE_LENGTH]; mutex_lock(&data->lock); next_update = data->last_updated + msecs_to_jiffies(data->update_interval); - if (!data->valid || time_after(jiffies, next_update)) { - ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN); - if (ret < 0) - goto unlock; - - usleep_range(SHT4X_MEAS_DELAY, - SHT4X_MEAS_DELAY + SHT4X_DELAY_EXTRA); - - ret = i2c_master_recv(client, raw_data, SHT4X_RESPONSE_LENGTH); - if (ret != SHT4X_RESPONSE_LENGTH) { - if (ret >= 0) - ret = -ENODATA; - - goto unlock; - } - - t_ticks = raw_data[0] << 8 | raw_data[1]; - rh_ticks = raw_data[3] << 8 | raw_data[4]; - - crc = crc8(sht4x_crc8_table, &raw_data[0], SHT4X_WORD_LEN, CRC8_INIT_VALUE); - if (crc != raw_data[2]) { - dev_err(&client->dev, "data integrity check failed\n"); - ret = -EIO; - goto unlock; - } - - crc = crc8(sht4x_crc8_table, &raw_data[3], SHT4X_WORD_LEN, CRC8_INIT_VALUE); - if (crc != raw_data[5]) { - dev_err(&client->dev, "data integrity check failed\n"); - ret = -EIO; - goto unlock; - } - - data->temperature = ((21875 * (int32_t)t_ticks) >> 13) - 45000; - data->humidity = ((15625 * (int32_t)rh_ticks) >> 13) - 6000; - data->last_updated = jiffies; - data->valid = true; + + if (data->valid && time_before_eq(jiffies, next_update)) + goto unlock; + + ret = i2c_master_send(client, cmd, SHT4X_CMD_LEN); + if (ret < 0) + goto unlock; + + usleep_range(SHT4X_MEAS_DELAY, SHT4X_MEAS_DELAY + SHT4X_DELAY_EXTRA); + + ret = i2c_master_recv(client, raw_data, SHT4X_RESPONSE_LENGTH); + if (ret != SHT4X_RESPONSE_LENGTH) { + if (ret >= 0) + ret = -ENODATA; + goto unlock; + } + + t_ticks = raw_data[0] << 8 | raw_data[1]; + rh_ticks = raw_data[3] << 8 | raw_data[4]; + + crc = crc8(sht4x_crc8_table, &raw_data[0], SHT4X_WORD_LEN, CRC8_INIT_VALUE); + if (crc != raw_data[2]) { + dev_err(&client->dev, "data integrity check failed\n"); + ret = -EIO; + goto unlock; } + crc = crc8(sht4x_crc8_table, &raw_data[3], SHT4X_WORD_LEN, CRC8_INIT_VALUE); + if (crc != raw_data[5]) { + dev_err(&client->dev, "data integrity check failed\n"); + ret = -EIO; + goto unlock; + } + + data->temperature = ((21875 * (int32_t)t_ticks) >> 13) - 45000; + data->humidity = ((15625 * (int32_t)rh_ticks) >> 13) - 6000; + data->last_updated = jiffies; + data->valid = true; + ret = 0; + unlock: mutex_unlock(&data->lock); return ret; @@ -132,19 +134,14 @@ static ssize_t sht4x_interval_write(struct sht4x_data *data, long val) return 0; } -/** - * sht4x_interval_read() - read the minimum poll interval - * in milliseconds - */ +/* sht4x_interval_read() - read the minimum poll interval in milliseconds */ static size_t sht4x_interval_read(struct sht4x_data *data, long *val) { *val = data->update_interval; return 0; } -/** - * sht4x_temperature1_read() - read the temperature in millidegrees - */ +/* sht4x_temperature1_read() - read the temperature in millidegrees */ static int sht4x_temperature1_read(struct sht4x_data *data, long *val) { int ret; @@ -158,9 +155,7 @@ static int sht4x_temperature1_read(struct sht4x_data *data, long *val) return 0; } -/** - * sht4x_humidity1_read() - read a relative humidity in millipercent - */ +/* sht4x_humidity1_read() - read a relative humidity in millipercent */ static int sht4x_humidity1_read(struct sht4x_data *data, long *val) { int ret; |