> -----Original Message----- > From: Shawn Guo <shawnguo@xxxxxxxxxx> > Sent: Monday, September 12, 2022 9:07 PM > To: Shenwei Wang <shenwei.wang@xxxxxxx> > Cc: Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof Kozlowski > <krzysztof.kozlowski+dt@xxxxxxxxxx>; Sascha Hauer <s.hauer@xxxxxxxxxxxxxx>; > Pengutronix Kernel Team <kernel@xxxxxxxxxxxxxx>; Peng Fan > <peng.fan@xxxxxxx>; devicetree@xxxxxxxxxxxxxxx; linux-arm- > kernel@xxxxxxxxxxxxxxxxxxx; imx@xxxxxxxxxxxxxxx; dl-linux-imx <linux- > imx@xxxxxxx> > Subject: Re: [EXT] Re: [PATCH v6 5/5] arm64: dts: freescale: add support for > i.MX8DXL EVK board > > Caution: EXT Email > > On Mon, Sep 12, 2022 at 02:35:18PM +0000, Shenwei Wang wrote: > > > > > > > -----Original Message----- > > > From: Shawn Guo <shawnguo@xxxxxxxxxx> > > > Sent: Monday, September 12, 2022 3:17 AM > > > To: Shenwei Wang <shenwei.wang@xxxxxxx> > > > Cc: Rob Herring <robh+dt@xxxxxxxxxx>; Krzysztof Kozlowski > > > <krzysztof.kozlowski+dt@xxxxxxxxxx>; Sascha Hauer > > > <s.hauer@xxxxxxxxxxxxxx>; Pengutronix Kernel Team > > > <kernel@xxxxxxxxxxxxxx>; Peng Fan <peng.fan@xxxxxxx>; > > > devicetree@xxxxxxxxxxxxxxx; linux-arm- kernel@xxxxxxxxxxxxxxxxxxx; > > > imx@xxxxxxxxxxxxxxx; dl-linux-imx <linux- imx@xxxxxxx> > > > > > > + > > > > > > + reg_fec1_sel: regulator-1 { > > > > > > + compatible = "regulator-fixed"; > > > > > > + regulator-name = "fec1_supply"; > > > > > > + regulator-min-microvolt = <3300000>; > > > > > > + regulator-max-microvolt = <3300000>; > > > > > > + gpio = <&pca6416_1 11 GPIO_ACTIVE_HIGH>; > > > > > > > > > > Missing enable-active-high? > > > > > > > > No. Enabling this regulator to select the fec1 interface instead of usdhc2. > > > Pulling this GPIO pin to low is to use FEC1 interface. > > > > > > Then the polarity cell should be GPIO_ACTIVE_LOW rather than > > > GPIO_ACTIVE_HIGH? > > > > > > > That doesn't matter since any GPIO phandle flags are ignored in the node of > "regulator-fixed". The final flag is only determined by the property of "enable- > active-high". If there is a "enable-active-high", the GPIO line works as active > high. If no such a property, it works as active low by default. Right? > > > > Well, we are talking about the correctness of DT (hardware description), not > how kernel driver works with DT. > So the correct syntax here is: if enable-active-high is used, the flag of gpio phandle should also be configured as "ACTIVE_HIGH". Otherwise, if no enable-active-high, the GPIO flag should be "ACTIVE_LOW". Is my understanding correct? Regards, Shenwei > Shawn