hwmon: (adt7475) temperature smoothing

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@alliedtelesis.co.nz>
Signed-off-by: Guenter Roeck <linux@roeck-us.net>

diff --git a/Documentation/hwmon/adt7475 b/Documentation/hwmon/adt7475
index dc0b55794c47cb05be4e5fb05203026c9ead872e..09d73a10644c4e69df9939e9f974995db76c226e 100644 (file)
--- a/Documentation/hwmon/adt7475
+++ b/Documentation/hwmon/adt7475
@@ -114,6 +114,10 @@ minimum (i.e. auto_point1_pwm). This behaviour can be configured using the
 pwm[1-*]_stall_disable 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 set the transition time
+set the value in ms in the temp[1-*]_smoothing sysfs attribute.
+
 Notes
 -----
 

diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index 3dfb16a95185bbb843d420cc44a00c6c50cf2d49..1baa213a60bd810975d3df3bfcfc4c3283b28175 100644 (file)
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -526,6 +526,88 @@ 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);
+       long val;
+
+       switch (sattr->index) {
+       case 0:
+               val = data->enh_acoustics[0] & 0xf;
+               break;
+       case 1:
+               val = (data->enh_acoustics[1] >> 4) & 0xf;
+               break;
+       case 2:
+       default:
+               val = data->enh_acoustics[1] & 0xf;
+               break;
+       }
+
+       if (val & 0x8)
+               return sprintf(buf, "%d\n", ad7475_st_map[val & 0x7]);
+       else
+               return sprintf(buf, "0\n");
+}
+
+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;
+       ulong val;
+
+       if (kstrtoul(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 = 0;
+               idx = 1;
+               break;
+       case 2:
+       default:
+               reg = REG_ENHANCE_ACOUSTICS2;
+               shift = 4;
+               idx = 1;
+               break;
+       }
+
+       if (val > 0) {
+               val = find_closest_descending(val, ad7475_st_map,
+                                             ARRAY_SIZE(ad7475_st_map));
+               val |= 0x8;
+       }
+
+       mutex_lock(&data->lock);
+
+       data->enh_acoustics[idx] &= ~(0xf << shift);
+       data->enh_acoustics[idx] |= (val << shift);
+
+       i2c_smbus_write_byte_data(client, reg, data->enh_acoustics[idx]);
+
+       mutex_unlock(&data->lock);
+
+       return count;
+}
+
 /*
  * Table of autorange values - the user will write the value in millidegrees,
  * and we'll convert it
@@ -1009,6 +1091,8 @@ 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, 0, 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,
@@ -1025,6 +1109,8 @@ 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, 0, 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);
@@ -1042,6 +1128,8 @@ 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, 0, 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);
@@ -1126,6 +1214,7 @@ 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_temp2_input.dev_attr.attr,
        &sensor_dev_attr_temp2_alarm.dev_attr.attr,
        &sensor_dev_attr_temp2_max.dev_attr.attr,
@@ -1135,6 +1224,7 @@ 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_temp3_input.dev_attr.attr,
        &sensor_dev_attr_temp3_fault.dev_attr.attr,
        &sensor_dev_attr_temp3_alarm.dev_attr.attr,
@@ -1145,6 +1235,7 @@ 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_fan1_input.dev_attr.attr,
        &sensor_dev_attr_fan1_min.dev_attr.attr,
        &sensor_dev_attr_fan1_alarm.dev_attr.attr,