Re: [RFC PATCH 3/3] hwmon: (adt7475) temperature smoothing

From: Guenter Roeck
Date: Tue May 02 2017 - 15:14:07 EST

On Tue, May 02, 2017 at 05:45:36PM +1200, Chris Packham wrote:
> When enabled temperature smoothing allows ramping the fan speed over a
> configurable period of time instead of jumping to the new speed
> instantaneously.
>
> Signed-off-by: Chris Packham <chris.packham@xxxxxxxxxxxxxxxxxxx>
> ---
> Documentation/hwmon/adt7475 | 5 ++
> drivers/hwmon/adt7475.c | 121 ++++++++++++++++++++++++++++++++++++++++++++
> 2 files changed, 126 insertions(+)
>
> diff --git a/Documentation/hwmon/adt7475 b/Documentation/hwmon/adt7475
> index 85dc9e17bdee..31b15cb910ea 100644
> --- a/Documentation/hwmon/adt7475
> +++ b/Documentation/hwmon/adt7475
> @@ -114,6 +114,11 @@ at the minimum (i.e. auto_point1_pwm). This can be configured using the
> pwm[1-*]_min sysfs attribute. A value of 0 means the fans will shut off. A
> value of 1 means the fans will run at auto_point1_pwm.
>
> +The responsiveness of the ADT747x to temperature changes can be configured.
> +This allows smoothing of the fan speed transition. To enable temperature
> +smoothing used the temp[1-*]_smoothing_enable sysfs attribute. To set the
> +transition time set the value in ms in the temp[1-*]_smoothing sysfs attribute.
> +
Does this require two attributes, or can setting '0' for temp[1-*]_smoothing
be used to disable it ?

Thanks,
Guenter

> Notes
> -----
>
> diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
> index 53f25bda0919..e1299eef7c51 100644
> --- a/drivers/hwmon/adt7475.c
> +++ b/drivers/hwmon/adt7475.c
> @@ -526,6 +526,109 @@ static ssize_t set_temp(struct device *dev, struct device_attribute *attr,
> return count;
> }
>
> +/* Assuming CONFIG6[SLOW] is 0 */
> +static const int ad7475_st_map[] = {
> + 37500, 18800, 12500, 7500, 4700, 3100, 1600, 800,
> +};
> +
> +static ssize_t show_temp_st(struct device *dev, struct device_attribute *attr,
> + char *buf)
> +{
> + struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> + struct i2c_client *client = to_i2c_client(dev);
> + struct adt7475_data *data = i2c_get_clientdata(client);
> + int shift, idx;
> + long val;
> +
> + switch (sattr->index) {
> + case 0:
> + shift = 0;
> + idx = 0;
> + break;
> + case 1:
> + shift = 4;
> + idx = 1;
> + break;
> + case 2:
> + shift = 0;
> + idx = 1;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + switch (sattr->nr) {
> + case CONTROL:
> + val = (data->enh_acou[idx] >> shift) & 0x8;
> + return sprintf(buf, "%d\n", !!val);
> + case MIN:
> + val = (data->enh_acou[idx] >> shift) & 0x7;
> + return sprintf(buf, "%d\n", ad7475_st_map[val]);
> + default:
> + return -EINVAL;
> + }
> +}
> +
> +static ssize_t set_temp_st(struct device *dev, struct device_attribute *attr,
> + const char *buf, size_t count)
> +{
> + struct sensor_device_attribute_2 *sattr = to_sensor_dev_attr_2(attr);
> + struct i2c_client *client = to_i2c_client(dev);
> + struct adt7475_data *data = i2c_get_clientdata(client);
> + unsigned char reg;
> + int shift, idx;
> + int mask;
> + long val;
> +
> + if (kstrtol(buf, 10, &val))
> + return -EINVAL;
> +
> + switch (sattr->index) {
> + case 0:
> + reg = REG_ENHANCE_ACOUSTICS1;
> + shift = 0;
> + idx = 0;
> + break;
> + case 1:
> + reg = REG_ENHANCE_ACOUSTICS2;
> + shift = 4;
> + idx = 1;
> + break;
> + case 2:
> + reg = REG_ENHANCE_ACOUSTICS2;
> + shift = 0;
> + idx = 1;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + switch (sattr->nr) {
> + case CONTROL:
> + val = !!val << 3;
> + mask = 0x8;
> + break;
> + case MIN:
> + val = find_closest_descending(val, ad7475_st_map,
> + ARRAY_SIZE(ad7475_st_map));
> + mask = 0x7;
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + mutex_lock(&data->lock);
> +
> + data->enh_acou[idx] &= ~(mask << shift);
> + data->enh_acou[idx] |= (val << shift);
> +
> + i2c_smbus_write_byte_data(client, reg, data->enh_acou[idx]);
> +
> + mutex_unlock(&data->lock);
> +
> + return count;
> +}
> +
> /*
> * Table of autorange values - the user will write the value in millidegrees,
> * and we'll convert it
> @@ -1008,6 +1111,10 @@ static SENSOR_DEVICE_ATTR_2(temp1_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> THERM, 0);
> static SENSOR_DEVICE_ATTR_2(temp1_crit_hyst, S_IRUGO | S_IWUSR, show_temp,
> set_temp, HYSTERSIS, 0);
> +static SENSOR_DEVICE_ATTR_2(temp1_smoothing, S_IRUGO | S_IWUSR, show_temp_st,
> + set_temp_st, MIN, 0);
> +static SENSOR_DEVICE_ATTR_2(temp1_smoothing_enable, S_IRUGO | S_IWUSR,
> + show_temp_st, set_temp_st, CONTROL, 0);
> static SENSOR_DEVICE_ATTR_2(temp2_input, S_IRUGO, show_temp, NULL, INPUT, 1);
> static SENSOR_DEVICE_ATTR_2(temp2_alarm, S_IRUGO, show_temp, NULL, ALARM, 1);
> static SENSOR_DEVICE_ATTR_2(temp2_max, S_IRUGO | S_IWUSR, show_temp, set_temp,
> @@ -1024,6 +1131,10 @@ static SENSOR_DEVICE_ATTR_2(temp2_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> THERM, 1);
> static SENSOR_DEVICE_ATTR_2(temp2_crit_hyst, S_IRUGO | S_IWUSR, show_temp,
> set_temp, HYSTERSIS, 1);
> +static SENSOR_DEVICE_ATTR_2(temp2_smoothing, S_IRUGO | S_IWUSR, show_temp_st,
> + set_temp_st, MIN, 1);
> +static SENSOR_DEVICE_ATTR_2(temp2_smoothing_enable, S_IRUGO | S_IWUSR,
> + show_temp_st, set_temp_st, CONTROL, 1);
> static SENSOR_DEVICE_ATTR_2(temp3_input, S_IRUGO, show_temp, NULL, INPUT, 2);
> static SENSOR_DEVICE_ATTR_2(temp3_alarm, S_IRUGO, show_temp, NULL, ALARM, 2);
> static SENSOR_DEVICE_ATTR_2(temp3_fault, S_IRUGO, show_temp, NULL, FAULT, 2);
> @@ -1041,6 +1152,10 @@ static SENSOR_DEVICE_ATTR_2(temp3_crit, S_IRUGO | S_IWUSR, show_temp, set_temp,
> THERM, 2);
> static SENSOR_DEVICE_ATTR_2(temp3_crit_hyst, S_IRUGO | S_IWUSR, show_temp,
> set_temp, HYSTERSIS, 2);
> +static SENSOR_DEVICE_ATTR_2(temp3_smoothing, S_IRUGO | S_IWUSR, show_temp_st,
> + set_temp_st, MIN, 2);
> +static SENSOR_DEVICE_ATTR_2(temp3_smoothing_enable, S_IRUGO | S_IWUSR,
> + show_temp_st, set_temp_st, CONTROL, 2);
> static SENSOR_DEVICE_ATTR_2(fan1_input, S_IRUGO, show_tach, NULL, INPUT, 0);
> static SENSOR_DEVICE_ATTR_2(fan1_min, S_IRUGO | S_IWUSR, show_tach, set_tach,
> MIN, 0);
> @@ -1125,6 +1240,8 @@ static struct attribute *adt7475_attrs[] = {
> &sensor_dev_attr_temp1_auto_point2_temp.dev_attr.attr,
> &sensor_dev_attr_temp1_crit.dev_attr.attr,
> &sensor_dev_attr_temp1_crit_hyst.dev_attr.attr,
> + &sensor_dev_attr_temp1_smoothing.dev_attr.attr,
> + &sensor_dev_attr_temp1_smoothing_enable.dev_attr.attr,
> &sensor_dev_attr_temp2_input.dev_attr.attr,
> &sensor_dev_attr_temp2_alarm.dev_attr.attr,
> &sensor_dev_attr_temp2_max.dev_attr.attr,
> @@ -1134,6 +1251,8 @@ static struct attribute *adt7475_attrs[] = {
> &sensor_dev_attr_temp2_auto_point2_temp.dev_attr.attr,
> &sensor_dev_attr_temp2_crit.dev_attr.attr,
> &sensor_dev_attr_temp2_crit_hyst.dev_attr.attr,
> + &sensor_dev_attr_temp2_smoothing.dev_attr.attr,
> + &sensor_dev_attr_temp2_smoothing_enable.dev_attr.attr,
> &sensor_dev_attr_temp3_input.dev_attr.attr,
> &sensor_dev_attr_temp3_fault.dev_attr.attr,
> &sensor_dev_attr_temp3_alarm.dev_attr.attr,
> @@ -1144,6 +1263,8 @@ static struct attribute *adt7475_attrs[] = {
> &sensor_dev_attr_temp3_auto_point2_temp.dev_attr.attr,
> &sensor_dev_attr_temp3_crit.dev_attr.attr,
> &sensor_dev_attr_temp3_crit_hyst.dev_attr.attr,
> + &sensor_dev_attr_temp3_smoothing.dev_attr.attr,
> + &sensor_dev_attr_temp3_smoothing_enable.dev_attr.attr,
> &sensor_dev_attr_fan1_input.dev_attr.attr,
> &sensor_dev_attr_fan1_min.dev_attr.attr,
> &sensor_dev_attr_fan1_alarm.dev_attr.attr,
> --
> 2.11.0.24.ge6920cf
>
> --
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