From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gianni Vialetto Date: Thu, 17 Jul 2014 06:29:29 +0000 Subject: Re: [lm-sensors] hwmon: question about the sysfs interface Message-Id: <20140717062929.GA1487@elysium.lan> List-Id: References: <20140714164728.GA1041@elysium.lan> <20140714172556.GA3753@roeck-us.net> In-Reply-To: <20140714172556.GA3753-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Guenter Roeck Cc: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org Hi Guenter, > For automatic fan control we don't really have a well defined ABI. > Part of the problem is that the mechanisms used by various chips are > quite different. > > Please have a look into Documentation/hwmon/nct6775. It is by far > the driver with the most comprehensive fan control mechanisms and > attributes. Would any of the attributes or atribute groups in this > driver meet your needs ? I could imagine that pwm1_target_temp > for the upper temperature limit and pwm1_temp_tolerance for the difference > between upper and lower limit might do. Then there are other attributes > such as pxm1_start, pwm1_floor, pwm1_step, and pwm1_max which you > could use to control pwm values further is that is possible with the > driver. Using pwm1_target_temp and pwm1_temp_tolerance seems a like nice idea, yes. Some of the other attributes are already used and I'm not certain how much I should change at this point. > An alternative would be to use two sets of pwm_auto_point attributes, > where the first set specifies the start pwm limit and the second > specifies the upper temperature and limit. So you would have something > like > > pwm1_auto_point1_pwm pwm at low temperature > pwm1_auto_point1_temp low temperature > > pwm1_auto_point2_pwm pwm at high temperature > pwm1_auto_point2_temp high temperature > > After all, there is no requirement that pwm must exactly match the configured > value; the above only means that the chip uses those values to calculate > the necessary fan speed. In addition to that, you could still have some > of the other attributes as needed, such as pwm1_min, pwm1_max, and so on. This was my initial plan, roughly, but I like the first solution more at this point. > Hope this helps, > Guenter Definitely. Thank you. Regards, Gianni _______________________________________________ lm-sensors mailing list lm-sensors@lm-sensors.org http://lists.lm-sensors.org/mailman/listinfo/lm-sensors From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gianni Vialetto Subject: Re: [lm-sensors] hwmon: question about the sysfs interface Date: Thu, 17 Jul 2014 08:29:29 +0200 Message-ID: <20140717062929.GA1487@elysium.lan> References: <20140714164728.GA1041@elysium.lan> <20140714172556.GA3753@roeck-us.net> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20140714172556.GA3753-0h96xk9xTtrk1uMJSBkQmQ@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: nouveau-bounces-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org Sender: "Nouveau" To: Guenter Roeck Cc: nouveau-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org, lm-sensors-GZX6beZjE8VD60Wz+7aTrA@public.gmane.org List-Id: nouveau.vger.kernel.org Hi Guenter, > For automatic fan control we don't really have a well defined ABI. > Part of the problem is that the mechanisms used by various chips are > quite different. > > Please have a look into Documentation/hwmon/nct6775. It is by far > the driver with the most comprehensive fan control mechanisms and > attributes. Would any of the attributes or atribute groups in this > driver meet your needs ? I could imagine that pwm1_target_temp > for the upper temperature limit and pwm1_temp_tolerance for the difference > between upper and lower limit might do. Then there are other attributes > such as pxm1_start, pwm1_floor, pwm1_step, and pwm1_max which you > could use to control pwm values further is that is possible with the > driver. Using pwm1_target_temp and pwm1_temp_tolerance seems a like nice idea, yes. Some of the other attributes are already used and I'm not certain how much I should change at this point. > An alternative would be to use two sets of pwm_auto_point attributes, > where the first set specifies the start pwm limit and the second > specifies the upper temperature and limit. So you would have something > like > > pwm1_auto_point1_pwm pwm at low temperature > pwm1_auto_point1_temp low temperature > > pwm1_auto_point2_pwm pwm at high temperature > pwm1_auto_point2_temp high temperature > > After all, there is no requirement that pwm must exactly match the configured > value; the above only means that the chip uses those values to calculate > the necessary fan speed. In addition to that, you could still have some > of the other attributes as needed, such as pwm1_min, pwm1_max, and so on. This was my initial plan, roughly, but I like the first solution more at this point. > Hope this helps, > Guenter Definitely. Thank you. Regards, Gianni