From: Steven Lee <steven_lee@aspeedtech.com>
To: Milton Miller II <miltonm@us.ibm.com>
Cc: Rob Herring <robh@kernel.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
Ulf Hansson <ulf.hansson@linaro.org>,
Ryan Chen <ryan_chen@aspeedtech.com>,
"moderated list:ASPEED SD/MMC DRIVER"
<linux-aspeed@lists.ozlabs.org>, Andrew Jeffery <andrew@aj.id.au>,
"open list:ASPEED SD/MMC DRIVER" <linux-mmc@vger.kernel.org>,
"moderated list:ASPEED SD/MMC DRIVER" <openbmc@lists.ozlabs.org>,
Ryan Chen <ryanchen.aspeed@gmail.com>,
"Adrian Hunter" <adrian.hunter@intel.com>,
open list <linux-kernel@vger.kernel.org>,
Chin-Ting Kuo <chin-ting_kuo@aspeedtech.com>,
"moderated list:ARM/ASPEED MACHINE SUPPORT"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH v1 1/2] dt-bindings: mmc: sdhci-of-aspeed: Add power-gpio and power-switch-gpio
Date: Tue, 13 Apr 2021 11:38:30 +0800 [thread overview]
Message-ID: <20210413033829.GB3522@aspeedtech.com> (raw)
In-Reply-To: <OF2606E97A.D9A04B5B-ON002586B6.000DC6EE-002586B6.000EF1DC@notes.na.collabserv.com>
The 04/13/2021 10:43, Milton Miller II wrote:
>
>
> -----"openbmc" <openbmc-bounces+miltonm=us.ibm.com@lists.ozlabs.org> wrote: -----
>
> >To: Rob Herring <robh@kernel.org>
> >From: Steven Lee
> >Sent by: "openbmc"
> >Date: 04/12/2021 08:31PM
> >Cc: "open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
> ><devicetree@vger.kernel.org>, Ulf Hansson <ulf.hansson@linaro.org>,
> >Ryan Chen <ryan_chen@aspeedtech.com>, "moderated list:ASPEED SD/MMC
> >DRIVER" <linux-aspeed@lists.ozlabs.org>, Andrew Jeffery
> ><andrew@aj.id.au>, "open list:ASPEED SD/MMC DRIVER"
> ><linux-mmc@vger.kernel.org>, "moderated list:ASPEED SD/MMC DRIVER"
> ><openbmc@lists.ozlabs.org>, Ryan Chen <ryanchen.aspeed@gmail.com>,
> >Adrian Hunter <adrian.hunter@intel.com>, open list
> ><linux-kernel@vger.kernel.org>, Chin-Ting Kuo
> ><chin-ting_kuo@aspeedtech.com>, "moderated list:ARM/ASPEED MACHINE
> >SUPPORT" <linux-arm-kernel@lists.infradead.org>
> >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@aspeedtech.com>
> >> > ---
> >> > .../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
> >> >
> >
> >
>
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next prev parent reply other threads:[~2021-04-13 3:41 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-08 1:52 [PATCH v1 0/2] mmc: sdhci-of-aspeed: Support toggling SD bus signal Steven Lee
2021-04-08 1:52 ` [PATCH v1 1/2] dt-bindings: mmc: sdhci-of-aspeed: Add power-gpio and power-switch-gpio Steven Lee
2021-04-09 18:41 ` Rob Herring
2021-04-13 1:30 ` Steven Lee
2021-04-13 2:43 ` Milton Miller II
2021-04-13 3:38 ` Steven Lee [this message]
2021-04-12 7:38 ` Ulf Hansson
2021-04-13 3:31 ` Steven Lee
2021-04-08 1:52 ` [PATCH v1 2/2] mmc: sdhci-of-aspeed: Support toggling SD bus signal voltage by GPIO Steven Lee
2021-04-09 4:14 ` Andrew Jeffery
2021-04-12 6:50 ` Steven Lee
2021-04-12 23:18 ` Andrew Jeffery
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