From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Peddell Subject: Re: [PATCHv1 2/3] arm: mvebu: add .dts file for Synology DS213j Date: Tue, 18 Nov 2014 08:41:27 +1000 Message-ID: <546A7997.1040603@killerwolves.net> References: <1eb26f8c1946622910a7e2318c895a7082fea7e5.1416095841.git.arno@natisbad.org> <20141116020024.GC15870@lunn.ch> <87d28nb83u.fsf@natisbad.org> <546931E1.5070909@killerwolves.net> <878ujas07o.fsf@natisbad.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <878ujas07o.fsf-LkuqDEemtHBg9hUCZPvPmw@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Arnaud Ebalard Cc: Andrew Lunn , Jason Cooper , Gregory Clement , Sebastian Hesselbarth , Mark Rutland , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Russell King , Pawel Moll , Stephen Warren , Ian Campbell , Rob Herring , linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org List-Id: devicetree@vger.kernel.org On 17/11/14 18:25, Arnaud Ebalard wrote: > Hi, > > Ben Peddell writes: > >> On 16/11/2014 11:14 PM, Arnaud Ebalard wrote: >>>>> + gpio-fan-100-32-35 { >>>> There is some logic to this naming, but i don't remember what it is. >>>> Did you check this is appropriate? >>> The 32-35 is for the MPP i.e. fan uses mpp32 to mpp35 (3 MPP for speed, >>> one for alarm). I don't know what the 100 part means. What I did is I >>> googled to see which fan supported kirkwood models have and noticed >>> that the DS212j uses the exact same fan, i.e. Y.S.Tech FD129225LL-N so >>> I opted for the same naming. >>> >>> On that aspect, you may be able to explain why the speed-map for this >>> fan goes up to 5000 RPM. This fan is supposed to operate at 1900RPM. >>> Note that it does not matter in practice. >> >> On the Kirkwood Diskstations, the first number (100, 120 or 150) refers >> to the middle of the three fan speed resistors, > > Would not have found that alone ;-) Thanks for clarifying. > >> the second number (15 or >> 32) refers to the first fan control pin, and the third number (18 or 35) >> refers to the first fan alarm pin. >> >> i.e. the 100-32-35 uses fan speed resistors of 33, 100 and 150 ohms, >> uses pins 32-34 for fan control, and uses pin 35 for the fan alarm. >> >> The 5000RPM was interpolated from my measured RPM pulse rate (4200PPM) >> of the 80mm fan in my DS211j (which uses the 150-32-35 fan config) at >> maximum RPM. > > Then, I think I need to change the speed map to have 1900 RPM as max > speed. Out of curiosity, how did you measured the RPM pulse rate > exactly? I hooked a logic analyzer to the sense pin and measured the pulse rate. Looking at the specifications of the fan in this unit (an EC7025L12ER), it has a maximum fan speed of 3000RPM, so it looks like it uses two pulses per revolution and not one as I had assumed when I created the speed map. -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html