From: Drew Fustini <dfustini@baylibre.com>
To: Conor Dooley <conor@kernel.org>
Cc: Ulf Hansson <ulf.hansson@linaro.org>,
Rob Herring <robh+dt@kernel.org>,
Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
Conor Dooley <conor+dt@kernel.org>,
Jisheng Zhang <jszhang@kernel.org>,
Adrian Hunter <adrian.hunter@intel.com>,
Guo Ren <guoren@kernel.org>, Fu Wei <wefu@redhat.com>,
Paul Walmsley <paul.walmsley@sifive.com>,
Palmer Dabbelt <palmer@dabbelt.com>,
Albert Ou <aou@eecs.berkeley.edu>,
Robert Nelson <robertcnelson@beagleboard.org>,
Jason Kridner <jkridner@beagleboard.org>,
Xi Ruoyao <xry111@xry111.site>, Han Gao <gaohan@iscas.ac.cn>,
Icenowy Zheng <uwu@icenowy.me>,
linux-mmc@vger.kernel.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org, linux-riscv@lists.infradead.org
Subject: Re: [PATCH 1/6] dt-bindings: mmc: sdhci-of-dwcmhsc: Add T-Head TH1520 support
Date: Fri, 22 Sep 2023 08:18:11 -0700 [thread overview]
Message-ID: <ZQ2tP48Z19C5xRug@x1> (raw)
In-Reply-To: <20230922-parish-ice-a22e93dc3027@spud>
On Fri, Sep 22, 2023 at 10:57:36AM +0100, Conor Dooley wrote:
> Hey Drew,
>
> On Thu, Sep 21, 2023 at 06:49:48PM -0700, Drew Fustini wrote:
> > Add compatible value for the T-Head TH1520 dwcmshc controller and add
> > thead,phy-pull-up property.
> >
> > Signed-off-by: Drew Fustini <dfustini@baylibre.com>
> > ---
> > Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml b/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml
> > index a43eb837f8da..46b768d46712 100644
> > --- a/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml
> > +++ b/Documentation/devicetree/bindings/mmc/snps,dwcmshc-sdhci.yaml
> > @@ -19,6 +19,7 @@ properties:
> > - rockchip,rk3568-dwcmshc
> > - rockchip,rk3588-dwcmshc
> > - snps,dwcmshc-sdhci
> > + - thead,th1520-dwcmshc
> >
> > reg:
> > maxItems: 1
> > @@ -60,6 +61,9 @@ properties:
> > description: Specify the number of delay for tx sampling.
> > $ref: /schemas/types.yaml#/definitions/uint8
> >
> > + thead,phy-pull-up:
> > + description: Enable weak pull-up on PHY pads
> > + type: boolean
>
> Why is the weak pull-up required? How would the dts author know if they
> need to use this property?
This is a good question, and I don't have a good reason beyond it is
what the vendor SDK was doing.
There are only two boards right now using the TH1520 that I know of.
Both the LPi4a [1] and the Ahead [2] have the pull-up property set on
all the mmc controller nodes their downstream device trees.
Rob suggested on #devicetree that it would be simpler to just enable it
in the driver and disable support when needed. I like this idea as it
will simplify this binding patch and the code in the driver patch.
Thanks,
Drew
[1] https://git.beagleboard.org/beaglev-ahead/BeagleBoard-DeviceTrees/-/blob/v5.10.x-ti-unified/src/riscv/light-beagle-ref.dts
[2] https://github.com/revyos/thead-kernel/blob/lpi4a/arch/riscv/boot/dts/thead/light-lpi4a-ref.dts
next prev parent reply other threads:[~2023-09-22 15:18 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-09-22 1:49 [PATCH 0/6] RISC-V: Add eMMC support for TH1520 boards Drew Fustini
2023-09-22 1:49 ` [PATCH 1/6] dt-bindings: mmc: sdhci-of-dwcmhsc: Add T-Head TH1520 support Drew Fustini
2023-09-22 9:57 ` Conor Dooley
2023-09-22 15:18 ` Drew Fustini [this message]
2023-09-23 8:10 ` Guo Ren
2023-09-24 21:04 ` Drew Fustini
2023-09-22 1:49 ` [PATCH 2/6] mmc: sdhci: add __sdhci_execute_tuning() to header Drew Fustini
2023-09-25 10:21 ` Adrian Hunter
2023-09-25 10:23 ` Xi Ruoyao
2023-09-25 10:31 ` Adrian Hunter
2023-09-25 14:41 ` Drew Fustini
2023-09-22 1:49 ` [PATCH 3/6] mmc: sdhci-of-dwcmshc: Add support for T-Head TH1520 Drew Fustini
2023-09-25 10:35 ` Adrian Hunter
2023-09-25 14:43 ` Drew Fustini
2023-10-04 16:19 ` Jisheng Zhang
2023-10-04 19:12 ` Drew Fustini
2023-09-22 1:49 ` [PATCH 4/6] riscv: dts: thead: Add TH1520 mmc controller and sdhci clock Drew Fustini
2023-09-22 1:49 ` [PATCH 5/6] riscv: dts: thead: Enable BeagleV Ahead eMMC controller Drew Fustini
2023-09-22 1:49 ` [PATCH 6/6] riscv: dts: thead: Enable LicheePi 4A " Drew Fustini
2023-09-22 11:41 ` [PATCH 0/6] RISC-V: Add eMMC support for TH1520 boards Xi Ruoyao
2023-09-22 16:23 ` Drew Fustini
2023-09-23 16:33 ` Xi Ruoyao
2023-09-23 0:11 ` Icenowy Zheng
2023-09-22 19:08 ` Robert Nelson
2023-09-22 22:48 ` Robert Nelson
2023-10-03 4:37 ` Drew Fustini
2023-10-04 11:30 ` Jisheng Zhang
2023-10-04 13:02 ` Lad, Prabhakar
2023-10-04 13:49 ` Robin Murphy
2023-10-04 14:02 ` Icenowy Zheng
2023-10-04 14:18 ` Robin Murphy
2023-10-04 14:46 ` Icenowy Zheng
2023-10-04 14:58 ` Icenowy Zheng
2023-10-04 16:03 ` Lad, Prabhakar
2023-10-04 17:16 ` Lad, Prabhakar
2023-10-04 18:49 ` Samuel Holland
2023-10-04 19:38 ` Robin Murphy
2023-10-04 20:47 ` Lad, Prabhakar
2023-10-05 6:57 ` Christoph Hellwig
2023-10-04 14:06 ` Jisheng Zhang
2023-10-04 15:27 ` Geert Uytterhoeven
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