Subject: Re: [PATCH] dt-bindings: nand: meson: fix controller clock
To:     Liang Yang <liang.yang@amlogic.com>,
        Miquel Raynal <miquel.raynal@bootlin.com>,
        Vignesh Raghavendra <vigneshr@ti.com>,
        linux-mtd@lists.infradead.org
Cc:     Richard Weinberger <richard@nod.at>,
        Jerome Brunet <jbrunet@baylibre.com>,
        Martin Blumenstingl <martin.blumenstingl@googlemail.com>,
        Kevin Hilman <khilman@baylibre.com>,
        Jianxin Pan <jianxin.pan@amlogic.com>,
        Victor Wan <victor.wan@amlogic.com>,
        XianWei Zhao <xianwei.zhao@amlogic.com>,
        Kelvin Zhang <kelvin.zhang@amlogic.com>,
        BiChao Zheng <bichao.zheng@amlogic.com>,
        YongHui Yu <yonghui.yu@amlogic.com>,
        linux-arm-kernel@lists.infradead.org,
        linux-amlogic@lists.infradead.org, linux-kernel@vger.kernel.org,
        devicetree@vger.kernel.org
References: <20220106033130.37623-1-liang.yang@amlogic.com>
From:   Neil Armstrong <narmstrong@baylibre.com>
Organization: Baylibre
Message-ID: <8439ec98-694e-0391-2a00-89e856024823@baylibre.com>
Date:   Thu, 6 Jan 2022 09:19:09 +0100
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Hi,

On 06/01/2022 04:31, Liang Yang wrote:
> Change-Id: I1425b491d8b95061e1ce358ef33143433fc94d24
> ---
>  .../bindings/mtd/amlogic,meson-nand.txt        | 18 +++---------------
>  1 file changed, 3 insertions(+), 15 deletions(-)
> 
> diff --git a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt
> index 5794ab1147c1..37f16fe4fe66 100644
> --- a/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt
> +++ b/Documentation/devicetree/bindings/mtd/amlogic,meson-nand.txt
> @@ -14,11 +14,6 @@ Required properties:
>  - clock-names: Should contain the following:
>  	"core" - NFC module gate clock
>  	"device" - device clock from eMMC sub clock controller
> -	"rx" - rx clock phase
> -	"tx" - tx clock phase
> -
> -- amlogic,mmc-syscon	: Required for NAND clocks, it's shared with SD/eMMC
> -				controller port C
>  
>  Optional children nodes:
>  Children nodes represent the available nand chips.
> @@ -28,11 +23,6 @@ see Documentation/devicetree/bindings/mtd/nand-controller.yaml for generic bindi
>  
>  Example demonstrate on AXG SoC:
>  
> -	sd_emmc_c_clkc: mmc@7000 {
> -		compatible = "amlogic,meson-axg-mmc-clkc", "syscon";
> -		reg = <0x0 0x7000 0x0 0x800>;
> -	};
> -
>  	nand-controller@7800 {
>  		compatible = "amlogic,meson-axg-nfc";
>  		reg = <0x0 0x7800 0x0 0x100>;
> @@ -41,11 +31,9 @@ Example demonstrate on AXG SoC:
>  		interrupts = <GIC_SPI 34 IRQ_TYPE_EDGE_RISING>;
>  
>  		clocks = <&clkc CLKID_SD_EMMC_C>,
> -			<&sd_emmc_c_clkc CLKID_MMC_DIV>,
> -			<&sd_emmc_c_clkc CLKID_MMC_PHASE_RX>,
> -			<&sd_emmc_c_clkc CLKID_MMC_PHASE_TX>;
> -		clock-names = "core", "device", "rx", "tx";
> -		amlogic,mmc-syscon = <&sd_emmc_c_clkc>;
> +			<&clkc CLKID_FCLK_DIV2>;
> +		clock-names = "core", "device";
> +		sd_emmc_c_clkc = <0xffe07000>;


sd_emmc_c_clkc should be documented, but it should be either:
- a syscon
- in reg

but since 0xffe07000 is part of the emmc memory space, you can't simply
put this address like that and pass it to a random undocumented property.

Adding "syscon" to the sd_emmc_c compatibles, and passing the sd_emmc_c node as syscon
could actually work.

Neil

>  
>  		pinctrl-names = "default";
>  		pinctrl-0 = <&nand_pins>;
>