On Thu, Jul 07, 2016 at 08:22:00PM -0700, Matt Ranostay wrote:
> The enables control of the SHT31 sensors heating element that can turned
> on to remove excess humidity.
>
> Cc: Guenter Roeck <linux@xxxxxxxxxxxx>
> Cc: David Frey <david.frey@xxxxxxxxxxxxx>
> Signed-off-by: Matt Ranostay <mranostay@xxxxxxxxx>
> ---
> Documentation/hwmon/sht3x | 2 ++
> drivers/hwmon/sht3x.c | 52 +++++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 54 insertions(+)
>
> diff --git a/Documentation/hwmon/sht3x b/Documentation/hwmon/sht3x
> index f5aa633ed383..fb1d3f1d641f 100644
> --- a/Documentation/hwmon/sht3x
> +++ b/Documentation/hwmon/sht3x
> @@ -67,6 +67,8 @@ temp1_alarm: alarm flag is set to 1 if the temperature is outside the
> configured limits. Alarm only works in periodic measure mode
> humidity1_alarm: alarm flag is set to 1 if the humidity is outside the
> configured limits. Alarm only works in periodic measure mode
> +heater_enable: heater enable, 1 for heating element turned on. Heating
> + element removes excess humidity from sensor
0 for off
> update_interval: update interval, 0 for single shot, interval in msec
> for periodic measurement. If the interval is not supported
> by the sensor, the next faster interval is chosen
> diff --git a/drivers/hwmon/sht3x.c b/drivers/hwmon/sht3x.c
> index b2c655add70e..05a925257938 100644
> --- a/drivers/hwmon/sht3x.c
> +++ b/drivers/hwmon/sht3x.c
> @@ -44,6 +44,10 @@ static const unsigned char sht3x_cmd_measure_nonblocking_lpm[] = { 0x24, 0x16 };
> static const unsigned char sht3x_cmd_measure_periodic_mode[] = { 0xe0, 0x00 };
> static const unsigned char sht3x_cmd_break[] = { 0x30, 0x93 };
>
> +/* commands for heater control */
> +static const unsigned char sht3x_cmd_heater_on[] = { 0x30, 0x6d };
> +static const unsigned char sht3x_cmd_heater_off[] = { 0x30, 0x66 };
> +
> /* other commands */
> static const unsigned char sht3x_cmd_read_status_reg[] = { 0xf3, 0x2d };
> static const unsigned char sht3x_cmd_clear_status_reg[] = { 0x30, 0x41 };
> @@ -507,6 +511,51 @@ static ssize_t humidity1_alarm_show(struct device *dev,
> return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x08));
> }
>
> +static ssize_t heater_enable_show(struct device *dev,
> + struct device_attribute *attr,
> + char *buf)
> +{
> + char buffer[SHT3X_WORD_LEN + SHT3X_CRC8_LEN];
> + int ret;
> +
> + ret = status_register_read(dev, attr, buffer,
> + SHT3X_WORD_LEN + SHT3X_CRC8_LEN);
> + if (ret)
> + return ret;
> +
> + return scnprintf(buf, PAGE_SIZE, "%d\n", !!(buffer[0] & 0x20));
> +}
> +
> +static ssize_t heater_enable_store(struct device *dev,
> + struct device_attribute *attr,
> + const char *buf,
> + size_t count)
> +{
> + struct sht3x_data *data = dev_get_drvdata(dev);
> + struct i2c_client *client = data->client;
> + int ret;
> + int status;
> +
> + ret = kstrtoint(buf, 0, &status);
kstrtobool() might be more appropriate here. Otherwise it is 0 for off, any
other value (including negative values) for on, which would be a bit odd.
> + if (ret)
> + return ret;
> +
> + mutex_lock(&data->data_lock);
I don't see why data_lock would be necessary here.
> + mutex_lock(&data->i2c_lock);
> +
> + if (status)
> + ret = i2c_master_send(client, (char *) &sht3x_cmd_heater_on,
> + SHT3X_CMD_LENGTH);
> + else
> + ret = i2c_master_send(client, (char *) &sht3x_cmd_heater_off,
> + SHT3X_CMD_LENGTH);
> +
> + mutex_unlock(&data->i2c_lock);
> + mutex_unlock(&data->data_lock);
> +
> + return ret;
> +}
> +
> static ssize_t update_interval_show(struct device *dev,
> struct device_attribute *attr,
> char *buf)
> @@ -612,6 +661,8 @@ static SENSOR_DEVICE_ATTR(humidity1_min_hyst, S_IRUGO | S_IWUSR,
> static SENSOR_DEVICE_ATTR(temp1_alarm, S_IRUGO, temp1_alarm_show, NULL, 0);
> static SENSOR_DEVICE_ATTR(humidity1_alarm, S_IRUGO, humidity1_alarm_show,
> NULL, 0);
> +static SENSOR_DEVICE_ATTR(heater_enable, S_IRUGO | S_IWUSR,
> + heater_enable_show, heater_enable_store, 0);
> static SENSOR_DEVICE_ATTR(update_interval, S_IRUGO | S_IWUSR,
> update_interval_show, update_interval_store, 0);
>
> @@ -628,6 +679,7 @@ static struct attribute *sht3x_attrs[] = {
> &sensor_dev_attr_humidity1_min_hyst.dev_attr.attr,
> &sensor_dev_attr_temp1_alarm.dev_attr.attr,
> &sensor_dev_attr_humidity1_alarm.dev_attr.attr,
> + &sensor_dev_attr_heater_enable.dev_attr.attr,
> &sensor_dev_attr_update_interval.dev_attr.attr,
> NULL
> };
> --
> 2.7.4
>
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