On Thu, 6 May 2021, at 19:33, Steven Lee wrote: > Add the description for describing the AST2600-A2 EVB reference design of > GPIO regulators. > > Signed-off-by: Steven Lee <steven_lee@xxxxxxxxxxxxxx> > --- > arch/arm/boot/dts/aspeed-ast2600-evb.dts | 15 +++++++++++++++ > 1 file changed, 15 insertions(+) > > diff --git a/arch/arm/boot/dts/aspeed-ast2600-evb.dts > b/arch/arm/boot/dts/aspeed-ast2600-evb.dts > index 2772796e215e..1ae0facc3d5f 100644 > --- a/arch/arm/boot/dts/aspeed-ast2600-evb.dts > +++ b/arch/arm/boot/dts/aspeed-ast2600-evb.dts > @@ -104,6 +104,21 @@ > status = "okay"; > }; > > +/* > + * The signal voltage of sdhci0 and sdhci1 on AST2600-A2 EVB is able to be > + * toggled by GPIO pins. > + * In the reference design, GPIOV0 of AST2600-A2 EVB is connected to the > + * power load switch that providing 3.3v to sdhci0 vdd, GPIOV1 is connected to > + * a 1.8v and a 3.3v power load switch that providing signal voltage to > + * sdhci0 bus. > + * If GPIOV0 is active high, sdhci0 is enabled, otherwise, sdhci0 is disabled. > + * If GPIOV1 is active high, 3.3v power load switch is enabled, sdhci0 signal > + * voltage is 3.3v, otherwise, 1.8v power load switch will be enabled, > + * sdhci0 signal voltage becomes 1.8v. > + * AST2600-A2 EVB also support toggling signal voltage for sdhci1. > + * The design is the same as sdhci0, it uses GPIOV2 as power-gpio and GPIOV3 > + * as power-switch-gpio. > + */ Okay, I think the comment is in the right place, but I feel this patch should also add the regulator nodes and hook them up to the SDHCIs. Given Rob isn't super keen on a second example in the binding document I think you can just cut the example out and paste it in here. Andrew
