From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tomasz Figa Subject: Re: [PATCH 5/5] ARM: dts: exynos4412-trats2: Add ADC's dt data to get temperature of SoC/battery Date: Tue, 11 Mar 2014 14:09:00 +0100 Message-ID: <531F0AEC.7010606@samsung.com> References: <1394524494-30641-1-git-send-email-cw00.choi@samsung.com> <1394524494-30641-6-git-send-email-cw00.choi@samsung.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <1394524494-30641-6-git-send-email-cw00.choi@samsung.com> Sender: linux-kernel-owner@vger.kernel.org To: Chanwoo Choi , kgene.kim@samsung.com Cc: linux-samsung-soc@vger.kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, kyungmin.park@samsung.com, rob.herring@calxeda.com, pawel.moll@arm.com, mark.rutland@arm.com, swarren@wwwdotorg.org, ijc+devicetree@hellion.org.uk, linux@arm.linux.org.uk List-Id: devicetree@vger.kernel.org Hi Chanwoo, On 11.03.2014 08:54, Chanwoo Choi wrote: > This patch use ADC to get the temperature of SoC/battery by using NTC thermistor > driver in hwmon. NTC thermistor driver covnvert ADC's raw data to temperature > by using following variables: > > - pullup-uv : Voltage > - pullup-ohm : Pull-up resistance > - pulldown-ohm : Pull-down resistance > - io-channels : It means ADC channel. > Those properties are well-defined in "ntc,ncp15wb473" DT bindings documentation. There is no need to repeat them here. > Signed-off-by: Chanwoo Choi > --- > arch/arm/boot/dts/exynos4412-trats2.dts | 21 +++++++++++++++++++++ > 1 file changed, 21 insertions(+) > > diff --git a/arch/arm/boot/dts/exynos4412-trats2.dts b/arch/arm/boot/dts/exynos4412-trats2.dts > index 4f851cc..fc517c3 100644 > --- a/arch/arm/boot/dts/exynos4412-trats2.dts > +++ b/arch/arm/boot/dts/exynos4412-trats2.dts > @@ -106,6 +106,27 @@ > }; > }; > > + adc: adc@126C0000 { > + vdd-supply = <&ldo3_reg>; > + status = "okay"; > + > + ncp15wb473@0 { style: Nodes should have generic names, e.g. thermistor@0. Also if node name is suffixed with @unit-address, then the node should have a reg property with its first entry corresponding to the unit-address. Now there is no physical unit-address definition for those thermistors, so they shouldn't use this naming pattern, but rather something like "thermistor-0" or "thermistor-ap". > + compatible = "ntc,ncp15wb473"; > + pullup-uv = <1800000>; /* VCC_1.8V_AP */ > + pullup-ohm = <100000>; /* 100K */ > + pulldown-ohm = <100000>; /* 100K */ > + io-channels = <&adc 1>; /* AP temperature */ > + }; > + > + ncp15wb473@1 { > + compatible = "ntc,ncp15wb473"; > + pullup-uv = <1800000>; /* VCC_1.8V_AP */ > + pullup-ohm = <100000>; /* 100K */ > + pulldown-ohm = <100000>; /* 100K */ > + io-channels = <&adc 2>; /* Battery temperature */ > + }; Anyway, I don't think it is correct to place IIO consumers under IIO provider node, because IIO is not a control bus, but rather a resource provider, like GPIO, clock, etc. So both thermistor nodes should be placed outside the adc node. (They might be grouped in a simple-bus subnode, though, to improve readability.) Best regards, Tomasz