Re: [PATCH v3 4/6] riscv: dts: microchip: drop duplicated MMC/SDHC node

From: <Conor.Dooley@microchip.com>
To: <krzysztof.kozlowski@canonical.com>, <ulf.hansson@linaro.org>,
	<robh+dt@kernel.org>, <paul.walmsley@sifive.com>,
	<palmer@dabbelt.com>, <aou@eecs.berkeley.edu>,
	<geert@linux-m68k.org>, <yamada.masahiro@socionext.com>,
	<piotrs@cadence.com>, <linux-mmc@vger.kernel.org>,
	<devicetree@vger.kernel.org>, <linux-kernel@vger.kernel.org>,
	<linux-riscv@lists.infradead.org>
Subject: Re: [PATCH v3 4/6] riscv: dts: microchip: drop duplicated MMC/SDHC node
Date: Tue, 21 Sep 2021 10:40:39 +0000	[thread overview]
Message-ID: <b83355ee-cce3-0a7d-a048-147dcb44b012@microchip.com> (raw)
In-Reply-To: <20210920150807.164673-4-krzysztof.kozlowski@canonical.com>

On 20/09/2021 16:08, Krzysztof Kozlowski wrote:
> EXTERNAL EMAIL: Do not click links or open attachments unless you know the content is safe
>
> Devicetree source is a description of hardware and hardware has only one
> block @20008000 which can be configured either as eMMC or SDHC.  Having
> two node for different modes is an obscure, unusual and confusing way to
> configure it.  Instead the board file is supposed to customize the block
> to its needs, e.g. to SDHC mode.
>
> This fixes dtbs_check warning:
>    arch/riscv/boot/dts/microchip/microchip-mpfs-icicle-kit.dt.yaml: sdhc@20008000: $nodename:0: 'sdhc@20008000' does not match '^mmc(@.*)?$'
>
> Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
>
> ---
>
> Changes since v1:
> 1. Move also bus-width, suggested by Geert.
> ---
>   .../microchip/microchip-mpfs-icicle-kit.dts   | 11 +++++++-
>   .../boot/dts/microchip/microchip-mpfs.dtsi    | 28 +------------------
>   2 files changed, 11 insertions(+), 28 deletions(-)
>
> diff --git a/arch/riscv/boot/dts/microchip/microchip-mpfs-icicle-kit.dts b/arch/riscv/boot/dts/microchip/microchip-mpfs-icicle-kit.dts
> index 07f1f3cab686..fc1e5869df1b 100644
> --- a/arch/riscv/boot/dts/microchip/microchip-mpfs-icicle-kit.dts
> +++ b/arch/riscv/boot/dts/microchip/microchip-mpfs-icicle-kit.dts
> @@ -51,8 +51,17 @@ &serial3 {
>          status = "okay";
>   };
>
> -&sdcard {
> +&mmc {
>          status = "okay";
> +
> +       bus-width = <4>;
> +       disable-wp;
> +       cap-sd-highspeed;
> +       card-detect-delay = <200>;
> +       sd-uhs-sdr12;
> +       sd-uhs-sdr25;
> +       sd-uhs-sdr50;
> +       sd-uhs-sdr104;
>   };
>
>   &emac0 {
> diff --git a/arch/riscv/boot/dts/microchip/microchip-mpfs.dtsi b/arch/riscv/boot/dts/microchip/microchip-mpfs.dtsi
> index 5084b93188f0..83bc14860960 100644
> --- a/arch/riscv/boot/dts/microchip/microchip-mpfs.dtsi
> +++ b/arch/riscv/boot/dts/microchip/microchip-mpfs.dtsi
> @@ -262,39 +262,13 @@ serial3: serial@20104000 {
>                          status = "disabled";
>                  };
>
> -               emmc: mmc@20008000 {
> -                       compatible = "cdns,sd4hc";
> -                       reg = <0x0 0x20008000 0x0 0x1000>;
> -                       interrupt-parent = <&plic>;
> -                       interrupts = <88 89>;
> -                       pinctrl-names = "default";
> -                       clocks = <&clkcfg 6>;
> -                       bus-width = <4>;
> -                       cap-mmc-highspeed;
> -                       mmc-ddr-3_3v;
> -                       max-frequency = <200000000>;
> -                       non-removable;
> -                       no-sd;
> -                       no-sdio;
> -                       voltage-ranges = <3300 3300>;
> -                       status = "disabled";
> -               };
> -
> -               sdcard: sdhc@20008000 {
> +               mmc: mmc@20008000 {
>                          compatible = "cdns,sd4hc";
>                          reg = <0x0 0x20008000 0x0 0x1000>;
>                          interrupt-parent = <&plic>;
>                          interrupts = <88>;
>                          pinctrl-names = "default";
>                          clocks = <&clkcfg 6>;
> -                       bus-width = <4>;
> -                       disable-wp;
> -                       cap-sd-highspeed;
> -                       card-detect-delay = <200>;
> -                       sd-uhs-sdr12;
> -                       sd-uhs-sdr25;
> -                       sd-uhs-sdr50;
> -                       sd-uhs-sdr104;
>                          max-frequency = <200000000>;
>                          status = "disabled";
>                  };
> --
> 2.30.2
>
Hi Krzysztof,
Seems I missed most of this series other than the new vendor name in the V1.

We have been redoing the device tree for the mpfs/icicle kit partly dye 
to some changes we made to the design. Previously SD and eMMC were 
different FPGA designs but now both are in the same design and managed 
by the bootloader, depending on where it finds the image to boot from.
Since then we've just been using the following single entry in the .dtsi:

         mmc: mmc@20008000 { /* Common node entry for emmc/sd */
             compatible = "cdns,sd4hc";
             reg = <0x0 0x20008000 0x0 0x1000>;
             clocks = <&clkcfg CLK_MMC>;
             interrupt-parent = <&plic>;
             interrupts = <PLIC_INT_MMC_MAIN PLIC_INT_MMC_WAKEUP>;
             bus-width = <4>;
             cap-mmc-highspeed;
             cap-sd-highspeed;
             no-1-8-v;
             disable-wp;
             max-frequency = <200000000>;
             status = "disabled";
         };

CLK_MMC is 6 & the interrupt numbers are 88 and 89 respectively.

Cheers, Conor.