[RFC PATCH 1/3] hwmon: (adt7475) replace find_nearest() with find_closest()

[RFC PATCH 1/3] hwmon: (adt7475) replace find_nearest() with find_closest()

[Chris Packham]

The adt7475 has had find_nearest() since it's creation in 2009. Since
then find_closest() has been introduced and several drivers have been
updated to use it. Update the adt7475 to use find_closest() and remove
the now unused find_nearest().

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
 drivers/hwmon/adt7475.c | 34 +++-------------------------------
 1 file changed, 3 insertions(+), 31 deletions(-)

diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index c803e3c5fcd4..ec0c43fbcdce 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -22,6 +22,7 @@
 #include <linux/hwmon-vid.h>
 #include <linux/err.h>
 #include <linux/jiffies.h>
+#include <linux/util_macros.h>
 
 /* Indexes for the sysfs hooks */
 
@@ -314,35 +315,6 @@ static void adt7475_write_word(struct i2c_client *client, int reg, u16 val)
 	i2c_smbus_write_byte_data(client, reg, val & 0xFF);
 }
 
-/*
- * Find the nearest value in a table - used for pwm frequency and
- * auto temp range
- */
-static int find_nearest(long val, const int *array, int size)
-{
-	int i;
-
-	if (val < array[0])
-		return 0;
-
-	if (val > array[size - 1])
-		return size - 1;
-
-	for (i = 0; i < size - 1; i++) {
-		int a, b;
-
-		if (val > array[i + 1])
-			continue;
-
-		a = val - array[i];
-		b = array[i + 1] - val;
-
-		return (a <= b) ? i : i + 1;
-	}
-
-	return 0;
-}
-
 static ssize_t show_voltage(struct device *dev, struct device_attribute *attr,
 			    char *buf)
 {
@@ -606,7 +578,7 @@ static ssize_t set_point2(struct device *dev, struct device_attribute *attr,
 	val -= temp;
 
 	/* Find the nearest table entry to what the user wrote */
-	val = find_nearest(val, autorange_table, ARRAY_SIZE(autorange_table));
+	val = find_closest(val, autorange_table, ARRAY_SIZE(autorange_table));
 
 	data->range[sattr->index] &= ~0xF0;
 	data->range[sattr->index] |= val << 4;
@@ -864,7 +836,7 @@ static ssize_t set_pwmfreq(struct device *dev, struct device_attribute *attr,
 	if (kstrtol(buf, 10, &val))
 		return -EINVAL;
 
-	out = find_nearest(val, pwmfreq_table, ARRAY_SIZE(pwmfreq_table));
+	out = find_closest(val, pwmfreq_table, ARRAY_SIZE(pwmfreq_table));
 
 	mutex_lock(&data->lock);
 
-- 
2.11.0.24.ge6920cf

[PATCH 2/3] hwmon: (adt7475) fan stall prevention

[Chris Packham]

By default adt7475 will stop the fans (pwm duty cycle 0%) when the
temperature drops past Tmin - hysteresis. Some systems want to keep the
fans moving even when the temperature drops so add new sysfs attributes
that configure the enhanced acoustics min 1-3 which allows the fans to
run at the minimum configure pwm duty cycle.

Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
---
pwmN_min is a horrible name but I really can't think of anything better.
I'm biased a little because that is essentially the name of the bits in
the datasheet. I'm open to suggestions.

 Documentation/hwmon/adt7475 |  5 +++++
 drivers/hwmon/adt7475.c     | 50 +++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 55 insertions(+)

diff --git a/Documentation/hwmon/adt7475 b/Documentation/hwmon/adt7475
index 0502f2b464e1..85dc9e17bdee 100644
--- a/Documentation/hwmon/adt7475
+++ b/Documentation/hwmon/adt7475
@@ -109,6 +109,11 @@ fan speed) is applied. PWM values range from 0 (off) to 255 (full speed).
 Fan speed may be set to maximum when the temperature sensor associated with
 the PWM control exceeds temp#_max.
 
+At Tmin - hysteresis the PWM output can either be off (0% duty cycle) or
+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.
+
 Notes
 -----
 
diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
index ec0c43fbcdce..53f25bda0919 100644
--- a/drivers/hwmon/adt7475.c
+++ b/drivers/hwmon/adt7475.c
@@ -79,6 +79,9 @@
 
 #define REG_TEMP_TRANGE_BASE	0x5F
 
+#define REG_ENHANCE_ACOUSTICS1	0x62
+#define REG_ENHANCE_ACOUSTICS2	0x63
+
 #define REG_PWM_MIN_BASE	0x64
 
 #define REG_TEMP_TMIN_BASE	0x67
@@ -209,6 +212,7 @@ struct adt7475_data {
 	u8 range[3];
 	u8 pwmctl[3];
 	u8 pwmchan[3];
+	u8 enh_acou[2];
 
 	u8 vid;
 	u8 vrm;
@@ -700,6 +704,43 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
 	data->pwm[sattr->nr][sattr->index] = clamp_val(val, 0, 0xFF);
 	i2c_smbus_write_byte_data(client, reg,
 				  data->pwm[sattr->nr][sattr->index]);
+	mutex_unlock(&data->lock);
+
+	return count;
+}
+
+
+static ssize_t show_pwm_min(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);
+	u8 mask = BIT(5 + sattr->index);
+
+	return sprintf(buf, "%d\n", !!(data->enh_acou[0] & mask));
+}
+
+static ssize_t set_pwm_min(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);
+	long val;
+	u8 mask = BIT(5 + sattr->index);
+
+	if (kstrtol(buf, 10, &val))
+		return -EINVAL;
+
+	mutex_lock(&data->lock);
+
+	data->enh_acou[0] &= ~mask;
+	if (val)
+		data->enh_acou[0] |= mask;
+
+	i2c_smbus_write_byte_data(client, REG_ENHANCE_ACOUSTICS1,
+				  data->enh_acou[0]);
 
 	mutex_unlock(&data->lock);
 
@@ -1028,6 +1069,8 @@ static SENSOR_DEVICE_ATTR_2(pwm1_auto_point1_pwm, S_IRUGO | S_IWUSR, show_pwm,
 			    set_pwm, MIN, 0);
 static SENSOR_DEVICE_ATTR_2(pwm1_auto_point2_pwm, S_IRUGO | S_IWUSR, show_pwm,
 			    set_pwm, MAX, 0);
+static SENSOR_DEVICE_ATTR_2(pwm1_min, S_IRUGO | S_IWUSR, show_pwm_min,
+			    set_pwm_min, 0, 0);
 static SENSOR_DEVICE_ATTR_2(pwm2, S_IRUGO | S_IWUSR, show_pwm, set_pwm, INPUT,
 			    1);
 static SENSOR_DEVICE_ATTR_2(pwm2_freq, S_IRUGO | S_IWUSR, show_pwmfreq,
@@ -1040,6 +1083,8 @@ static SENSOR_DEVICE_ATTR_2(pwm2_auto_point1_pwm, S_IRUGO | S_IWUSR, show_pwm,
 			    set_pwm, MIN, 1);
 static SENSOR_DEVICE_ATTR_2(pwm2_auto_point2_pwm, S_IRUGO | S_IWUSR, show_pwm,
 			    set_pwm, MAX, 1);
+static SENSOR_DEVICE_ATTR_2(pwm2_min, S_IRUGO | S_IWUSR, show_pwm_min,
+			    set_pwm_min, 0, 1);
 static SENSOR_DEVICE_ATTR_2(pwm3, S_IRUGO | S_IWUSR, show_pwm, set_pwm, INPUT,
 			    2);
 static SENSOR_DEVICE_ATTR_2(pwm3_freq, S_IRUGO | S_IWUSR, show_pwmfreq,
@@ -1052,6 +1097,8 @@ static SENSOR_DEVICE_ATTR_2(pwm3_auto_point1_pwm, S_IRUGO | S_IWUSR, show_pwm,
 			    set_pwm, MIN, 2);
 static SENSOR_DEVICE_ATTR_2(pwm3_auto_point2_pwm, S_IRUGO | S_IWUSR, show_pwm,
 			    set_pwm, MAX, 2);
+static SENSOR_DEVICE_ATTR_2(pwm3_min, S_IRUGO | S_IWUSR, show_pwm_min,
+			    set_pwm_min, 0, 2);
 
 /* Non-standard name, might need revisiting */
 static DEVICE_ATTR_RW(pwm_use_point2_pwm_at_crit);
@@ -1112,12 +1159,14 @@ static struct attribute *adt7475_attrs[] = {
 	&sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
 	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm1_min.dev_attr.attr,
 	&sensor_dev_attr_pwm3.dev_attr.attr,
 	&sensor_dev_attr_pwm3_freq.dev_attr.attr,
 	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
 	&sensor_dev_attr_pwm3_auto_channels_temp.dev_attr.attr,
 	&sensor_dev_attr_pwm3_auto_point1_pwm.dev_attr.attr,
 	&sensor_dev_attr_pwm3_auto_point2_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm3_min.dev_attr.attr,
 	&dev_attr_pwm_use_point2_pwm_at_crit.attr,
 	NULL,
 };
@@ -1136,6 +1185,7 @@ static struct attribute *pwm2_attrs[] = {
 	&sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
 	&sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
 	&sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
+	&sensor_dev_attr_pwm2_min.dev_attr.attr,
 	NULL
 };
 
-- 
2.11.0.24.ge6920cf

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

[Chris Packham]

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

Re: [PATCH 2/3] hwmon: (adt7475) fan stall prevention

[Guenter Roeck]

On Tue, May 02, 2017 at 05:45:35PM +1200, Chris Packham wrote:
> By default adt7475 will stop the fans (pwm duty cycle 0%) when the
> temperature drops past Tmin - hysteresis. Some systems want to keep the
> fans moving even when the temperature drops so add new sysfs attributes
> that configure the enhanced acoustics min 1-3 which allows the fans to
> run at the minimum configure pwm duty cycle.
> 
> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
> ---
> pwmN_min is a horrible name but I really can't think of anything better.
> I'm biased a little because that is essentially the name of the bits in
> the datasheet. I'm open to suggestions.

pwmX_min is also traditionally the mimimum permitted pwm value,
not a boolean. This would be more appropriate to reflect the PWMmin
register values (0x64 to 0x66). Similar for pwmX_max if you want to
add support for it.
It might make sense to combine pwmX_min==0 with clearing the
respective bit in the REG_ENHANCE_ACOUSTICS[12] register. This way
we would only need one attribute to support both.

Guenter

> 
>  Documentation/hwmon/adt7475 |  5 +++++
>  drivers/hwmon/adt7475.c     | 50 +++++++++++++++++++++++++++++++++++++++++++++
>  2 files changed, 55 insertions(+)
> 
> diff --git a/Documentation/hwmon/adt7475 b/Documentation/hwmon/adt7475
> index 0502f2b464e1..85dc9e17bdee 100644
> --- a/Documentation/hwmon/adt7475
> +++ b/Documentation/hwmon/adt7475
> @@ -109,6 +109,11 @@ fan speed) is applied. PWM values range from 0 (off) to 255 (full speed).
>  Fan speed may be set to maximum when the temperature sensor associated with
>  the PWM control exceeds temp#_max.
>  
> +At Tmin - hysteresis the PWM output can either be off (0% duty cycle) or
> +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.
> +
>  Notes
>  -----
>  
> diff --git a/drivers/hwmon/adt7475.c b/drivers/hwmon/adt7475.c
> index ec0c43fbcdce..53f25bda0919 100644
> --- a/drivers/hwmon/adt7475.c
> +++ b/drivers/hwmon/adt7475.c
> @@ -79,6 +79,9 @@
>  
>  #define REG_TEMP_TRANGE_BASE	0x5F
>  
> +#define REG_ENHANCE_ACOUSTICS1	0x62
> +#define REG_ENHANCE_ACOUSTICS2	0x63
> +
>  #define REG_PWM_MIN_BASE	0x64
>  
>  #define REG_TEMP_TMIN_BASE	0x67
> @@ -209,6 +212,7 @@ struct adt7475_data {
>  	u8 range[3];
>  	u8 pwmctl[3];
>  	u8 pwmchan[3];
> +	u8 enh_acou[2];
>  
>  	u8 vid;
>  	u8 vrm;
> @@ -700,6 +704,43 @@ static ssize_t set_pwm(struct device *dev, struct device_attribute *attr,
>  	data->pwm[sattr->nr][sattr->index] = clamp_val(val, 0, 0xFF);
>  	i2c_smbus_write_byte_data(client, reg,
>  				  data->pwm[sattr->nr][sattr->index]);
> +	mutex_unlock(&data->lock);
> +
> +	return count;
> +}
> +
> +
> +static ssize_t show_pwm_min(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);
> +	u8 mask = BIT(5 + sattr->index);
> +
> +	return sprintf(buf, "%d\n", !!(data->enh_acou[0] & mask));
> +}
> +
> +static ssize_t set_pwm_min(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);
> +	long val;
> +	u8 mask = BIT(5 + sattr->index);
> +
> +	if (kstrtol(buf, 10, &val))
> +		return -EINVAL;
> +
> +	mutex_lock(&data->lock);
> +
> +	data->enh_acou[0] &= ~mask;
> +	if (val)
> +		data->enh_acou[0] |= mask;
> +
> +	i2c_smbus_write_byte_data(client, REG_ENHANCE_ACOUSTICS1,
> +				  data->enh_acou[0]);
>  
>  	mutex_unlock(&data->lock);
>  
> @@ -1028,6 +1069,8 @@ static SENSOR_DEVICE_ATTR_2(pwm1_auto_point1_pwm, S_IRUGO | S_IWUSR, show_pwm,
>  			    set_pwm, MIN, 0);
>  static SENSOR_DEVICE_ATTR_2(pwm1_auto_point2_pwm, S_IRUGO | S_IWUSR, show_pwm,
>  			    set_pwm, MAX, 0);
> +static SENSOR_DEVICE_ATTR_2(pwm1_min, S_IRUGO | S_IWUSR, show_pwm_min,
> +			    set_pwm_min, 0, 0);
>  static SENSOR_DEVICE_ATTR_2(pwm2, S_IRUGO | S_IWUSR, show_pwm, set_pwm, INPUT,
>  			    1);
>  static SENSOR_DEVICE_ATTR_2(pwm2_freq, S_IRUGO | S_IWUSR, show_pwmfreq,
> @@ -1040,6 +1083,8 @@ static SENSOR_DEVICE_ATTR_2(pwm2_auto_point1_pwm, S_IRUGO | S_IWUSR, show_pwm,
>  			    set_pwm, MIN, 1);
>  static SENSOR_DEVICE_ATTR_2(pwm2_auto_point2_pwm, S_IRUGO | S_IWUSR, show_pwm,
>  			    set_pwm, MAX, 1);
> +static SENSOR_DEVICE_ATTR_2(pwm2_min, S_IRUGO | S_IWUSR, show_pwm_min,
> +			    set_pwm_min, 0, 1);
>  static SENSOR_DEVICE_ATTR_2(pwm3, S_IRUGO | S_IWUSR, show_pwm, set_pwm, INPUT,
>  			    2);
>  static SENSOR_DEVICE_ATTR_2(pwm3_freq, S_IRUGO | S_IWUSR, show_pwmfreq,
> @@ -1052,6 +1097,8 @@ static SENSOR_DEVICE_ATTR_2(pwm3_auto_point1_pwm, S_IRUGO | S_IWUSR, show_pwm,
>  			    set_pwm, MIN, 2);
>  static SENSOR_DEVICE_ATTR_2(pwm3_auto_point2_pwm, S_IRUGO | S_IWUSR, show_pwm,
>  			    set_pwm, MAX, 2);
> +static SENSOR_DEVICE_ATTR_2(pwm3_min, S_IRUGO | S_IWUSR, show_pwm_min,
> +			    set_pwm_min, 0, 2);
>  
>  /* Non-standard name, might need revisiting */
>  static DEVICE_ATTR_RW(pwm_use_point2_pwm_at_crit);
> @@ -1112,12 +1159,14 @@ static struct attribute *adt7475_attrs[] = {
>  	&sensor_dev_attr_pwm1_auto_channels_temp.dev_attr.attr,
>  	&sensor_dev_attr_pwm1_auto_point1_pwm.dev_attr.attr,
>  	&sensor_dev_attr_pwm1_auto_point2_pwm.dev_attr.attr,
> +	&sensor_dev_attr_pwm1_min.dev_attr.attr,
>  	&sensor_dev_attr_pwm3.dev_attr.attr,
>  	&sensor_dev_attr_pwm3_freq.dev_attr.attr,
>  	&sensor_dev_attr_pwm3_enable.dev_attr.attr,
>  	&sensor_dev_attr_pwm3_auto_channels_temp.dev_attr.attr,
>  	&sensor_dev_attr_pwm3_auto_point1_pwm.dev_attr.attr,
>  	&sensor_dev_attr_pwm3_auto_point2_pwm.dev_attr.attr,
> +	&sensor_dev_attr_pwm3_min.dev_attr.attr,
>  	&dev_attr_pwm_use_point2_pwm_at_crit.attr,
>  	NULL,
>  };
> @@ -1136,6 +1185,7 @@ static struct attribute *pwm2_attrs[] = {
>  	&sensor_dev_attr_pwm2_auto_channels_temp.dev_attr.attr,
>  	&sensor_dev_attr_pwm2_auto_point1_pwm.dev_attr.attr,
>  	&sensor_dev_attr_pwm2_auto_point2_pwm.dev_attr.attr,
> +	&sensor_dev_attr_pwm2_min.dev_attr.attr,
>  	NULL
>  };
>  
> -- 
> 2.11.0.24.ge6920cf
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
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> More majordomo info at  http://vger.kernel.org/majordomo-info.html

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

[Guenter Roeck]

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@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.
> +
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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Re: [RFC PATCH 3/3] hwmon: (adt7475) temperature smoothing

[Chris Packham]

On 03/05/17 07:14, Guenter Roeck wrote:
> 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@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.
>> +
> Does this require two attributes, or can setting '0' for temp[1-*]_smoothing
> be used to disable it ?
>

One attribute could be made to work. I was following asc7621.c but from 
a usability perspective having to set the two attributes is not 
particularly convenient. The only argument for separating them is to 
allow smoothing at whatever the hardware default is.

Re: [PATCH 2/3] hwmon: (adt7475) fan stall prevention

[Chris Packham]

On 03/05/17 06:07, Guenter Roeck wrote:
> On Tue, May 02, 2017 at 05:45:35PM +1200, Chris Packham wrote:
>> By default adt7475 will stop the fans (pwm duty cycle 0%) when the
>> temperature drops past Tmin - hysteresis. Some systems want to keep the
>> fans moving even when the temperature drops so add new sysfs attributes
>> that configure the enhanced acoustics min 1-3 which allows the fans to
>> run at the minimum configure pwm duty cycle.
>>
>> Signed-off-by: Chris Packham <chris.packham@alliedtelesis.co.nz>
>> ---
>> pwmN_min is a horrible name but I really can't think of anything better.
>> I'm biased a little because that is essentially the name of the bits in
>> the datasheet. I'm open to suggestions.
>
> pwmX_min is also traditionally the mimimum permitted pwm value,
> not a boolean. This would be more appropriate to reflect the PWMmin
> register values (0x64 to 0x66). Similar for pwmX_max if you want to
> add support for it.

For the adt7476 driver these are used as pwmN_auto_point[12]_pwm.

> It might make sense to combine pwmX_min==0 with clearing the
> respective bit in the REG_ENHANCE_ACOUSTICS[12] register. This way
> we would only need one attribute to support both.

I could add code such that if pwmN_auto_point1_pwm > 0. The bit in 
REG_ENHANCE_ACOUSTICS is set but that would be a change in existing 
behaviour.