From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from bh-25.webhostbox.net ([208.91.199.152]:57699 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751860AbdECQKu (ORCPT ); Wed, 3 May 2017 12:10:50 -0400 Date: Wed, 3 May 2017 09:10:44 -0700 From: Guenter Roeck To: Chris Packham Cc: linux-hwmon@vger.kernel.org, jdelvare@suse.com, Jonathan Corbet , linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [RFC PATCH v2 2/3] hwmon: (adt7475) fan stall prevention Message-ID: <20170503161044.GA9471@roeck-us.net> References: <20170503004009.23769-1-chris.packham@alliedtelesis.co.nz> <20170503004009.23769-3-chris.packham@alliedtelesis.co.nz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20170503004009.23769-3-chris.packham@alliedtelesis.co.nz> Sender: linux-hwmon-owner@vger.kernel.org List-Id: linux-hwmon@vger.kernel.org On Wed, May 03, 2017 at 12:40:08PM +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 > --- > Changes in v2: > - use pwmN_stall_dis as the attribute name. I think this describes the purpose > pretty well. I went with a new attribute instead of overloading > pwmN_auto_point1_pwm so this doesn't affect existing users. > > 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..63507402cd4f 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 behaviour be configured using the > +pwm[1-*]_stall_dis sysfs attribute. A value of 0 means the fans will shut off. That is really an awkward attribute name. I'll have to think about this some more. Guenter > +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..85957324cd85 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_stall_dis(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_stall_dis(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_stall_dis, S_IRUGO | S_IWUSR, show_stall_dis, > + set_stall_dis, 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_stall_dis, S_IRUGO | S_IWUSR, show_stall_dis, > + set_stall_dis, 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_stall_dis, S_IRUGO | S_IWUSR, show_stall_dis, > + set_stall_dis, 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_stall_dis.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_stall_dis.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_stall_dis.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