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Date:   Mon, 1 Apr 2019 19:52:35 +0200
From:   Miquel Raynal <miquel.raynal@bootlin.com>
To:     Mason Yang <masonccyang@mxic.com.tw>
Cc:     broonie@kernel.org, marek.vasut@gmail.com,
        linux-kernel@vger.kernel.org, linux-spi@vger.kernel.org,
        bbrezillon@kernel.org, dwmw2@infradead.org, lee.jones@linaro.org,
        robh+dt@kernel.org, mark.rutland@arm.com,
        computersforpeace@gmail.com, paul.burton@mips.com, stefan@agner.ch,
        christophe.kerello@st.com, liang.yang@amlogic.com,
        geert@linux-m68k.org, devicetree@vger.kernel.org,
        marcel.ziswiler@toradex.com, linux-mtd@lists.infradead.org,
        richard@nod.at, juliensu@mxic.com.tw, zhengxunli@mxic.com.tw
Subject: Re: [PATCH 4/7] dt-bindings: mfd: Document Macronix MX25F0A
 controller bindings
Message-ID: <20190401193431.3e8788a0@xps13>
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        <1553768318-23149-5-git-send-email-masonccyang@mxic.com.tw>
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Hi Mason,

Mason Yang <masonccyang@mxic.com.tw> wrote on Thu, 28 Mar 2019 18:18:35
+0800:

> Document the bindings used by the Macronix MX25F0A MFD controller.
> 
> Signed-off-by: Mason Yang <masonccyang@mxic.com.tw>
> ---
>  .../devicetree/bindings/mfd/mxic-mx25f0a.txt       | 66 ++++++++++++++++++++++
>  1 file changed, 66 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mfd/mxic-mx25f0a.txt
> 
> diff --git a/Documentation/devicetree/bindings/mfd/mxic-mx25f0a.txt b/Documentation/devicetree/bindings/mfd/mxic-mx25f0a.txt
> new file mode 100644
> index 0000000..53b4839
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mfd/mxic-mx25f0a.txt
> @@ -0,0 +1,66 @@
> +Macronix MX25F0A Multi-Function Device Tree Bindings
> +----------------------------------------------------
> +
> +MX25F0A is a MultiFunction Device with SPI and raw NAND, which
> +supports either spi host controller or raw nand controller.
> +
> +Required properties:
> +- compatible: should be "mxic,mx25f0a-mfd"

Should probably be "mxic,mx25f0a"

> +- #address-cells: should be 1
> +- #size-cells: should be 0
> +- reg: should contain 2 entries, one for the registers and one for the direct
> +       mapping area in SPI mode.
> +- reg-names: should contain "regs" and "dirmap"
> +- interrupts: interrupt line connected to this MFD controller
> +
> +Required nodes:
> + - spi :
> +	Node for configuring the SPI controller driver.
> +	Required properties:
> +		- compatible = "mxicy,mx25f0a-spi";
> +		- clock-names: should contain "ps_clk", "send_clk" and
> +			       "send_dly_clk"
> +		- clocks: should contain 3 entries for the "ps_clk", "send_clk"
> +			  and "send_dly_clk" clocks
> +
> +- nand :
> +	Node for configuring the raw nand controller driver.
> +	Required properties:
> +		- compatible = "mxicy,mx25f0a-nand-ctlr";
> +		- nand-ecc-mode = "soft";
> +		- nand-ecc-algo = "bch";

You can have only one node at a time. You can add a mxic,mode property
being either "spi-controller" or "nand-controller".

> +
> +Example:
> +
> +	mxic: mx25f0a-mfd@43c30000 {
> +		compatible = "mxic,mx25f0a-mfd";
> +		reg = <0x43c30000 0x10000>, <0xa0000000 0x4000000>;
> +		reg-names = "regs", "dirmap";
> +		#address-cells = <1>;
> +		#size-cells = <0>;
> +
> +		/* either spi or nand */
> +		spi {
> +			compatible = "mxicy,mx25f0a-spi";
> +			clocks = <&clkwizard 0>, <&clkwizard 1>, <&clkc 15>;
> +			clock-names = "send_clk", "send_dly_clk", "ps_clk";
> +			#address-cells = <1>;
> +			#size-cells = <0>;
> +
> +			flash@0 {
> +				compatible = "jedec,spi-nor";
> +				reg = <0>;
> +				spi-max-frequency = <25000000>;
> +				spi-tx-bus-width = <4>;
> +				spi-rx-bus-width = <4>;
> +			};
> +		};
> +
> +		nand {
> +			compatible = "mxicy,mx25f0a-nand-ctlr";
> +			nand-ecc-mode = "soft";
> +			nand-ecc-algo = "bch";
> +			nand-ecc-step-size = <512>;
> +			nand-ecc-strength = <8>;

Are you sure you want soft correction? (I have not checked the driver
yet). For hw correction, I prefer to drop the two step-size/strength
properties. These values will be derived depending on the chip's
requirements.


Thanks,
Miquèl