Anson Huang Best Regards! > -----Original Message----- > From: Anson Huang > Sent: Friday, April 27, 2018 9:37 AM > To: 'Fabio Estevam' <festevam@xxxxxxxxx> > Cc: Shawn Guo <shawnguo@xxxxxxxxxx>; Sascha Hauer > <kernel@xxxxxxxxxxxxxx>; Fabio Estevam <fabio.estevam@xxxxxxx>; Rob > Herring <robh+dt@xxxxxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>; > dl-linux-imx <linux-imx@xxxxxxx>; moderated list:ARM/FREESCALE IMX / MXC > ARM ARCHITECTURE <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; open list:OPEN > FIRMWARE AND FLATTENED DEVICE TREE BINDINGS > <devicetree@xxxxxxxxxxxxxxx>; linux-kernel <linux-kernel@xxxxxxxxxxxxxxx>; > Andy Duan <fugang.duan@xxxxxxx> > Subject: RE: [PATCH 4/5] ARM: dts: imx6sx-sabreauto: add fec support > > > > Anson Huang > Best Regards! > > > > -----Original Message----- > > From: Fabio Estevam [mailto:festevam@xxxxxxxxx] > > Sent: Friday, April 27, 2018 1:29 AM > > To: Anson Huang <anson.huang@xxxxxxx> > > Cc: Shawn Guo <shawnguo@xxxxxxxxxx>; Sascha Hauer > > <kernel@xxxxxxxxxxxxxx>; Fabio Estevam <fabio.estevam@xxxxxxx>; Rob > > Herring <robh+dt@xxxxxxxxxx>; Mark Rutland <mark.rutland@xxxxxxx>; > > dl-linux-imx <linux-imx@xxxxxxx>; moderated list:ARM/FREESCALE IMX / > > MXC ARM ARCHITECTURE <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx>; open > > list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS > > <devicetree@xxxxxxxxxxxxxxx>; linux-kernel > > <linux-kernel@xxxxxxxxxxxxxxx>; Andy Duan <fugang.duan@xxxxxxx> > > Subject: Re: [PATCH 4/5] ARM: dts: imx6sx-sabreauto: add fec support > > > > On Thu, Apr 26, 2018 at 3:57 AM, Anson Huang <anson.huang@xxxxxxx> > > wrote: > > > > > The 'phy-supply' is for enabling/disabling phy regulator, but here > > > the > > > MAX7322 IO0 is NOT for enabling/disabling PHY regulator, it is for > > > IO voltage switch between 1.5V and 1.8V, our ENET IO can work with > > > both 1.5V > > and 1.8V, so any config is OK for ENET function. > > > > Thanks for the clarification. > > > > > The 1.5V/1.8V selection is a one time setting thing, that means we > > > only need to config it once during boot up, most of i.MX platforms > > > does NOT provide such voltage switch function for ENET IO, on this > > > 6SX sabre auto board, it is more like a backup or validation > > > purpose. With default > > settings, ENET's function is NOT impacted at all. > > > > > > I think we can add a gpio regulator for it and let the regulator > > > initialization set the GPIO Level for fec, such below, with " > > > enable-active-high " present, GPIO will be at LOW and voltage is > > > 1.5V, without > > this property, GPIO will be HIGH and voltage will be 1.8V. > > > + reg_fec: fec_io_supply { > > > + compatible = "regulator-gpio"; > > > + regulator-name = "1.8V_1.5V_FEC"; > > > + regulator-min-microvolt = <1500000>; > > > + regulator-max-microvolt = <1800000>; > > > + states = <1500000 0x0 1800000 0x1>; > > > + enable-gpio = <&max7322 0 > > GPIO_ACTIVE_HIGH>; > > > + vin-supply = <&sw2_reg>; > > > + enable-active-high; > > > > If there is no consumer for this regulator, the regulator API will disable it. > > > > It seems you need a 'regulator-always-on;'. > > GPIO regulator is slight different when regulator framework try to disable those > unused regulator in late phase, in _regulator_do_disable, the GPIO regulator > only got disabled when it is explicitly enabled before (ena_gpio_state is set when > regulator is enabled), but this reg_fec is NOT getting enabled, since it only has > voltage switch function. But I agree that we can anyway add > 'regulator-always-on' > to avoid any confusion, will send out new patch, thanks! > > if (rdev->ena_pin) { > if (rdev->ena_gpio_state) { > ret = regulator_ena_gpio_ctrl(rdev, false); > > > Anson. I found if I add ' regulator-always-on ', the regulator core will explicitly enable this GPIO regulator and cause MAX7322 IO0 to be HIGH and the FEC IO will be 1.8V, since the GPIO regulator state 1 means 1.8V, but what we want for now is 1.5V, so I think we should NOT add ' regulator-always-on ', if anyone wants to use 1.8V IO voltage, they can enable this GPIO regulator to get 1.8V. So I think V5 patch set is just what we want, we want to use the OFF state's voltage (1.5V) of this MAX7322 IO0 GPIO regulator. Thanks. Anson. > > > > > > > > + }; > > > + > > > > > > Anson. > > > ��.n��������+%������w��{.n����z�{��ܨ}���Ơz�j:+v�����w����ޙ��&�)ߡ�a����z�ޗ���ݢj��w�f
