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

Chris Packham
2017-05-02T05:46:07Z

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>
---
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.
+
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