The 04/13/2021 10:43, Milton Miller II wrote: > > > -----"openbmc" <openbmc-bounces+miltonm=us.ibm.com@xxxxxxxxxxxxxxxx> wrote: ----- > > >To: Rob Herring <robh@xxxxxxxxxx> > >From: Steven Lee > >Sent by: "openbmc" > >Date: 04/12/2021 08:31PM > >Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" > ><devicetree@xxxxxxxxxxxxxxx>, Ulf Hansson <ulf.hansson@xxxxxxxxxx>, > >Ryan Chen <ryan_chen@xxxxxxxxxxxxxx>, "moderated list:ASPEED SD/MMC > >DRIVER" <linux-aspeed@xxxxxxxxxxxxxxxx>, Andrew Jeffery > ><andrew@xxxxxxxx>, "open list:ASPEED SD/MMC DRIVER" > ><linux-mmc@xxxxxxxxxxxxxxx>, "moderated list:ASPEED SD/MMC DRIVER" > ><openbmc@xxxxxxxxxxxxxxxx>, Ryan Chen <ryanchen.aspeed@xxxxxxxxx>, > >Adrian Hunter <adrian.hunter@xxxxxxxxx>, open list > ><linux-kernel@xxxxxxxxxxxxxxx>, Chin-Ting Kuo > ><chin-ting_kuo@xxxxxxxxxxxxxx>, "moderated list:ARM/ASPEED MACHINE > >SUPPORT" <linux-arm-kernel@xxxxxxxxxxxxxxxxxxx> > >Subject: [EXTERNAL] Re: [PATCH v1 1/2] dt-bindings: mmc: > >sdhci-of-aspeed: Add power-gpio and power-switch-gpio > > > >The 04/10/2021 02:41, Rob Herring wrote: > >> On Thu, Apr 08, 2021 at 09:52:17AM +0800, Steven Lee wrote: > >> > AST2600-A2 EVB provides the reference design for enabling SD bus > >power > >> > and toggling SD bus signal voltage by GPIO pins. > >> > Add the definition and example for power-gpio and > >power-switch-gpio > >> > properties. > >> > > >> > In the reference design, GPIOV0 of AST2600-A2 EVB is connected to > >power > >> > load switch that providing 3.3v to SD1 bus vdd. GPIOV1 is > >connected to > >> > a 1.8v and a 3.3v power load switch that providing signal voltage > >to > >> > SD1 bus. > >> > If GPIOV0 is active high, SD1 bus is enabled. Otherwise, SD1 bus > >is > >> > disabled. > >> > If GPIOV1 is active high, 3.3v power load switch is enabled, SD1 > >signal > >> > voltage is 3.3v. Otherwise, 1.8v power load switch will be > >enabled, SD1 > >> > signal voltage becomes 1.8v. > >> > > >> > AST2600-A2 EVB also support toggling signal voltage for SD2 bus. > >> > The design is the same as SD1 bus. It uses GPIOV2 as power-gpio > >and GPIOV3 > >> > as power-switch-gpio. > >> > > >> > Signed-off-by: Steven Lee <steven_lee@xxxxxxxxxxxxxx> > >> > --- > >> > .../devicetree/bindings/mmc/aspeed,sdhci.yaml | 25 > >+++++++++++++++++++ > >> > 1 file changed, 25 insertions(+) > >> > > >> > diff --git > >a/Documentation/devicetree/bindings/mmc/aspeed,sdhci.yaml > >b/Documentation/devicetree/bindings/mmc/aspeed,sdhci.yaml > >> > index 987b287f3bff..515a74614f3c 100644 > >> > --- a/Documentation/devicetree/bindings/mmc/aspeed,sdhci.yaml > >> > +++ b/Documentation/devicetree/bindings/mmc/aspeed,sdhci.yaml > >> > @@ -37,6 +37,14 @@ properties: > >> > clocks: > >> > maxItems: 1 > >> > description: The SD/SDIO controller clock gate > >> > + power-gpio: > >> > >> '-gpios' is the preferred form even if just 1. > >> > > > >Thanks for reviewing, I will change the name. > > is this a clock gate or a power on gpio? > > A power on gpio. > > > >> > + description: > >> > + The GPIO for enabling/disabling SD bus power. > >> > + maxItems: 1 > >> > >> blank line > >> > > > >I will remove the blank line. > > > >> > + power-switch-gpio: > >> > + description: > >> > + The GPIO for toggling the signal voltage between 3.3v and > >1.8v. > > Which way does it toggle for which voltage? > > Oh, you said in the change log but not in the binding. > I will add description in the binding. > But please, use gpio controled regulators as Ulf suggested and is > already used by other mmc controllers upstream. > > https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/tree/ > Documentation/devicetree/bindings/regulator/gpio-regulator.yaml > Thanks for reviewing and the information, I will use gpio-regulator instead of power-gpio and power-switch-gpio. > Ulf> Please do not model these as GPIO pins like this. Instead, it's better > Ulf> to model them as gpio regulators, since the mmc core manages them as > Ulf> regulators. > Ulf> > Ulf> We have a vmmc regulator (corresponding to vdd) and a vqmmc regulator > Ulf> (corresponding the signal-voltage level). These are also described in > Ulf> the common mmc DT bindings, see > Ulf> Documentation/devicetree/bindings/mmc/mmc-controller.yaml > Ulf> . > > milton > > >> > + maxItems: 1 > >> > > >> > patternProperties: > >> > "^sdhci@[0-9a-f]+$": > >> > @@ -61,6 +69,14 @@ patternProperties: > >> > sdhci,auto-cmd12: > >> > type: boolean > >> > description: Specifies that controller should use auto > >CMD12 > >> > + power-gpio: > >> > + description: > >> > + The GPIO for enabling/disabling SD bus power. > >> > + maxItems: 1 > >> > + power-switch-gpio: > >> > + description: > >> > + The GPIO for toggling the signal voltage between 3.3v > >and 1.8v. > >> > + maxItems: 1 > >> > required: > >> > - compatible > >> > - reg > >> > @@ -80,6 +96,7 @@ required: > >> > examples: > >> > - | > >> > #include <dt-bindings/clock/aspeed-clock.h> > >> > + #include <dt-bindings/gpio/aspeed-gpio.h> > >> > sdc@1e740000 { > >> > compatible = "aspeed,ast2500-sd-controller"; > >> > reg = <0x1e740000 0x100>; > >> > @@ -94,6 +111,10 @@ examples: > >> > interrupts = <26>; > >> > sdhci,auto-cmd12; > >> > clocks = <&syscon ASPEED_CLK_SDIO>; > >> > + power-gpio = <&gpio0 ASPEED_GPIO(V, 0) > >> > + GPIO_ACTIVE_HIGH>; > >> > + power-switch-gpio = <&gpio0 ASPEED_GPIO(V, > >1) > >> > + GPIO_ACTIVE_HIGH>; > >> > }; > >> > > >> > sdhci1: sdhci@200 { > >> > @@ -102,5 +123,9 @@ examples: > >> > interrupts = <26>; > >> > sdhci,auto-cmd12; > >> > clocks = <&syscon ASPEED_CLK_SDIO>; > >> > + power-gpio = <&gpio0 ASPEED_GPIO(V, 2) > >> > + GPIO_ACTIVE_HIGH>; > >> > + power-switch-gpio = <&gpio0 ASPEED_GPIO(V, > >3) > >> > + GPIO_ACTIVE_HIGH>; > >> > }; > >> > }; > >> > -- > >> > 2.17.1 > >> > > > > > >
