[RFC PATCH 0/3] hwmon: (adt7475) small enhancements

[RFC PATCH 0/3] hwmon: (adt7475) small enhancements

[Chris Packham]

This is a series of small enhancements to the adt7475 driver. We're using an
adt7476 chip in several network switches and generally speaking the
requirement for this type of equipment is to keep the fan moving so that we
know it is working when we need it.

Chris Packham (3):
  hwmon: (adt7475) replace find_nearest() with find_closest()
  hwmon: (adt7475) fan stall prevention
  hwmon: (adt7475) temperature smoothing

 Documentation/hwmon/adt7475 |  10 +++
 drivers/hwmon/adt7475.c     | 205 +++++++++++++++++++++++++++++++++++++-------
 2 files changed, 184 insertions(+), 31 deletions(-)

-- 
2.11.0.24.ge6920cf

[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
> the body of a message to majordomo@vger.kernel.org
> 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
> 
> --
> To unsubscribe from this list: send the line "unsubscribe linux-hwmon" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html

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.