From mboxrd@z Thu Jan 1 00:00:00 1970 From: Guenter Roeck Subject: Re: [PATCH RFC 1/3] dt-bindings: hwmon: Add tachometer interrupt to pwm-fan Date: Wed, 30 Jan 2019 12:35:25 -0800 Message-ID: <20190130203525.GA23614@roeck-us.net> References: <1548860827-29796-1-git-send-email-stefan.wahren@i2se.com> <1548860827-29796-2-git-send-email-stefan.wahren@i2se.com> <20190130172815.GC14781@roeck-us.net> <625436113.118199.1548879811777@email.ionos.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <625436113.118199.1548879811777@email.ionos.de> Sender: linux-kernel-owner@vger.kernel.org To: Stefan Wahren Cc: Kamil Debski , Bartlomiej Zolnierkiewicz , Jean Delvare , Rob Herring , Mark Rutland , linux-hwmon@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org List-Id: devicetree@vger.kernel.org On Wed, Jan 30, 2019 at 09:23:31PM +0100, Stefan Wahren wrote: > Hi Guenter, > > > Guenter Roeck hat am 30. Januar 2019 um 18:28 geschrieben: > > > > > > On Wed, Jan 30, 2019 at 04:07:05PM +0100, Stefan Wahren wrote: > > > This adds the tachometer interrupt to the pwm-fan binding, which is > > > necessary for RPM support. > > > > > > Signed-off-by: Stefan Wahren > > > --- > > > Documentation/devicetree/bindings/hwmon/pwm-fan.txt | 3 +++ > > > 1 file changed, 3 insertions(+) > > > > > > diff --git a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt > > > index 49ca5d8..7f69b0b 100644 > > > --- a/Documentation/devicetree/bindings/hwmon/pwm-fan.txt > > > +++ b/Documentation/devicetree/bindings/hwmon/pwm-fan.txt > > > @@ -8,6 +8,9 @@ Required properties: > > > > > > Optional properties: > > > - fan-supply : phandle to the regulator that provides power to the fan > > > +- interrupts : contains a single interrupt specifier which describes the > > > + tachometer pin output of a 2 pulse-per-revolution fan. > > > + See interrupt-controller/interrupts.txt for the format. > > > > So a hypothetical {1,4} pulse-per-revolution fan would explicitly not be > > supported ? Why ? > > i could add an additional property to specify the pulse per revolution and use the 2 as default (according to the Intel spec for 4 pin pwm fan) which should fit in most cases. > That would be a possibility and make sense, but that is not the point here. The "interrupts" property does not and should not care how many pulses per revolution the fan provides. Guenter