Re: [PATCH 3/3] ARM: dts: imx6sx-udoo-neo: Add SD

[Shawn Guo]

On Mon, Aug 08, 2016 at 05:00:41PM +0200, Andreas Färber wrote:
> Am 08.08.2016 um 16:12 schrieb Shawn Guo:
> > On Tue, Jul 05, 2016 at 06:04:10AM +0200, Andreas Färber wrote:
> >> Enable the SDHC node and model the SDIO_PWR GPIO as a regulator.
> >> Use the SD card as default trigger for the red LED.
> >>
> >> Cc: Ettore Chimenti <ettore.chimenti@xxxxxxxx>
> >> Signed-off-by: Andreas Färber <afaerber@xxxxxxx>
> >> ---
> >>  
> >>
> >>  arch/arm/boot/dts/imx6sx-udoo-neo.dtsi | 34 ++++++++++++++++++++++++++++++++++
> >>  1 file changed, 34 insertions(+)
> >>
> >> diff --git a/arch/arm/boot/dts/imx6sx-udoo-neo.dtsi b/arch/arm/boot/dts/imx6sx-udoo-neo.dtsi
> >> index e074409644d8..85f5e8606dab 100644
> >> --- a/arch/arm/boot/dts/imx6sx-udoo-neo.dtsi
> >> +++ b/arch/arm/boot/dts/imx6sx-udoo-neo.dtsi
> >> @@ -56,6 +56,7 @@
> >>  			label = "udoo-neo:red:mmc";
> >>  			gpios = <&gpio6 0 GPIO_ACTIVE_HIGH>;
> >>  			default-state = "off";
> >> +			linux,default-trigger = "mmc0";
> >>  		};
> >>  
> >>  		orange {
> >> @@ -64,6 +65,17 @@
> >>  			default-state = "keep";
> >>  		};
> >>  	};
> >> +
> >> +	sdio_pwr_reg: sd-gpio-regulator {
> >> +		compatible = "regulator-fixed";
> >> +		gpio = <&gpio6 1 GPIO_ACTIVE_HIGH>;
> >> +		enable-active-high;
> >> +		regulator-name = "SDIO_PWR";
> >> +		regulator-min-microvolt = <3300000>;
> >> +		regulator-max-microvolt = <3300000>;
> >> +		regulator-boot-on;
> >> +		regulator-always-on;
> >> +	};
> > 
> > Is it correct to model SDIO power control GPIO as a boot-on and
> > always-on fixed regulator?  It will be powered-on even when SDIO driver
> > is not enabled or loaded.
> 
> AFAIR the issue was that the driver does not use any -supply properties
> where we could hook this regulator up for enabling. So modeling it as an
> always-on regulator seemed like the only way to ensure it gets enabled
> without relying on the bootloader?

If I understand it correctly, SDHCI driver calls
mmc_regulator_get_supply() to handle vmmc and vqmmc supply.  Can
vmmc-supply be used here?

Shawn