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Message-ID: <20200303224706.GA22867@bogus>
Date: Tue, 3 Mar 2020 16:47:06 -0600
From: Rob Herring <robh@...nel.org>
To: Chuanhong Guo <gch981213@...il.com>
Cc: linux-mediatek@...ts.infradead.org, linux-spi@...r.kernel.org,
linux-mtd@...ts.infradead.org, devicetree@...r.kernel.org,
Miquel Raynal <miquel.raynal@...tlin.com>,
Richard Weinberger <richard@....at>,
Vignesh Raghavendra <vigneshr@...com>,
Matthias Brugger <matthias.bgg@...il.com>,
Mark Brown <broonie@...nel.org>,
Tudor Ambarus <tudor.ambarus@...rochip.com>,
"moderated list:ARM/Mediatek SoC support"
<linux-arm-kernel@...ts.infradead.org>,
open list <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v2 3/4] dt-bindings: convert mtk-quadspi binding doc for
spi-mtk-nor
On Fri, Feb 28, 2020 at 12:36:35PM +0800, Chuanhong Guo wrote:
> spi-mtk-nor is a driver to replace mtk-quadspi and they have almost
> the same device-tree bindings. Reuse this binding documentation and
> convert it for new driver:
>
> 1. "Mediatek SoCs" -> "Mediatek ARM SoCs" because MTK MIPS SoCs
> use different controllers.
> 2. document "interrupts" as a required property because it's
> available on all SoCs with this controller and new driver takes
> advantages of it. It's implemented as optional only to maintain
> backward compatibility.
> 3. replace binding example with a mt7629 one because this is the
> only one I know the interrupt assignment.
That doesn't really matter. It would be less churn without that change
and examples are just examples.
>
> Signed-off-by: Chuanhong Guo <gch981213@...il.com>
> ---
> Change since v1:
> none
>
> .../mtk-quadspi.txt => spi/spi-mtk-nor.txt} | 34 ++++++++-----------
> 1 file changed, 15 insertions(+), 19 deletions(-)
> rename Documentation/devicetree/bindings/{mtd/mtk-quadspi.txt => spi/spi-mtk-nor.txt} (62%)
>
> diff --git a/Documentation/devicetree/bindings/mtd/mtk-quadspi.txt b/Documentation/devicetree/bindings/spi/spi-mtk-nor.txt
> similarity index 62%
> rename from Documentation/devicetree/bindings/mtd/mtk-quadspi.txt
> rename to Documentation/devicetree/bindings/spi/spi-mtk-nor.txt
> index a12e3b5c495d..829da480b9a9 100644
> --- a/Documentation/devicetree/bindings/mtd/mtk-quadspi.txt
> +++ b/Documentation/devicetree/bindings/spi/spi-mtk-nor.txt
> @@ -1,4 +1,4 @@
> -* Serial NOR flash controller for MediaTek SoCs
> +* SPI NOR flash controller for MediaTek ARM SoCs
>
> Required properties:
> - compatible: For mt8173, compatible should be "mediatek,mt8173-nor",
> @@ -13,6 +13,7 @@ Required properties:
> "mediatek,mt7629-nor", "mediatek,mt8173-nor"
> "mediatek,mt8173-nor"
> - reg: physical base address and length of the controller's register
> +- interrupts: Interrupt number used by the controller.
> - clocks: the phandle of the clocks needed by the nor controller
> - clock-names: the names of the clocks
> the clocks should be named "spi" and "sf". "spi" is used for spi bus,
> @@ -22,29 +23,24 @@ Required properties:
> - #address-cells: should be <1>
> - #size-cells: should be <0>
>
> -The SPI flash must be a child of the nor_flash node and must have a
> -compatible property. Also see jedec,spi-nor.txt.
> -
> -Required properties:
> -- compatible: May include a device-specific string consisting of the manufacturer
> - and name of the chip. Must also include "jedec,spi-nor" for any
> - SPI NOR flash that can be identified by the JEDEC READ ID opcode (0x9F).
> -- reg : Chip-Select number
> +There should be only one spi slave device following generic spi bindings.
> +It's not recommended to use this controller for devices other than SPI NOR
> +flash due to limited transfer capability of this controller.
>
> Example:
> +#include <dt-bindings/interrupt-controller/irq.h>
> +#include <dt-bindings/interrupt-controller/arm-gic.h>
> +#include <dt-bindings/clock/mt7629-clk.h>
>
> -nor_flash: spi@...0d000 {
> - compatible = "mediatek,mt8173-nor";
> - reg = <0 0x1100d000 0 0xe0>;
> - clocks = <&pericfg CLK_PERI_SPI>,
> - <&topckgen CLK_TOP_SPINFI_IFR_SEL>;
> +spi_nor: spi@...14000 {
> + compatible = "mediatek,mt7629-nor",
> + "mediatek,mt8173-nor";
> + reg = <0x11014000 0xe0>;
> + interrupts = <GIC_SPI 88 IRQ_TYPE_LEVEL_LOW>;
> + clocks = <&pericfg CLK_PERI_FLASH_PD>,
> + <&topckgen CLK_TOP_FLASH_SEL>;
> clock-names = "spi", "sf";
> #address-cells = <1>;
> #size-cells = <0>;
> -
> - flash@0 {
> - compatible = "jedec,spi-nor";
> - reg = <0>;
> - };
Better to leave this in the example IMO.
Rob
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