Re: [PATCH v3 3/4] hwmon: (adt7475) temperature smoothing
From: Guenter Roeck
Date: Sun May 14 2017 - 11:40:53 EST
On 05/10/2017 08:45 PM, 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>
---
Changes in v2:
- use a single tempN_smoothing attribute
This is a bit confusing. tempN suggests that the attribute would be associated
with a given temperature, not with fan control. Not that I have a better idea
for an attribute name, though, so unless you find a better name I am ok with it.
Changes in v3:
- change enh_acou to enh_acoustics
- simplify show_temp_st()
Documentation/hwmon/adt7475 | 4 ++
drivers/hwmon/adt7475.c | 93 +++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 97 insertions(+)
diff --git a/Documentation/hwmon/adt7475 b/Documentation/hwmon/adt7475
index 3990bae60e78..e82b24ec4b07 100644
--- 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_dis 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 4d6c625fec70..f7322330789c 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -526,6 +526,90 @@ 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:
+ val = data->enh_acoustics[1] & 0xf;
+ break;
+ default:
+ return -EINVAL;
This will never happen and, if it does, would indicate a bug, not invalid input.
I kind of dislike dead code; it just bloats the kernel. Please either use
default: for or together with case 2:, or make it if/else.
+ }
+
+ 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 = 4;
+ idx = 1;
+ break;
+ case 2:
+ reg = REG_ENHANCE_ACOUSTICS2;
+ shift = 0;
+ idx = 1;
+ break;
Is this correct ? It associates
temp1_smoothing -> remote 1
temp2_smoothing -> remote 2
temp3_smoothing -> local
which, unless I am missing something, doesn't match temp1/2/3.
+ default:
+ return -EINVAL;
Same as above.
+ }
+
+ 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
@@ -1008,6 +1092,8 @@ 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,
@@ -1024,6 +1110,8 @@ 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);
@@ -1041,6 +1129,8 @@ 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);
@@ -1125,6 +1215,7 @@ 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,
@@ -1134,6 +1225,7 @@ 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,
@@ -1144,6 +1236,7 @@ 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,