From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Norris Subject: Re: [PATCH 1/3] doc: dt: add documentation for Mediatek spi-nor controller Date: Fri, 11 Sep 2015 14:47:04 -0700 Message-ID: <20150911214704.GD11487@google.com> References: <1441705796-11365-1-git-send-email-bayi.cheng@mediatek.com> <1441705796-11365-2-git-send-email-bayi.cheng@mediatek.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <1441705796-11365-2-git-send-email-bayi.cheng-NuS5LvNUpcJWk0Htik3J/w@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Bayi Cheng Cc: David Woodhouse , Rob Herring , Pawel Moll , Mark Rutland , Ian Campbell , Kumar Gala , Matthias Brugger , Daniel Kurtz , Sascha Hauer , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-mediatek-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mtd-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, Marek Vasut List-Id: devicetree@vger.kernel.org On Tue, Sep 08, 2015 at 05:49:54PM +0800, Bayi Cheng wrote: > Add device tree binding documentation for serial flash with > Mediatek serial flash controller > > Signed-off-by: Bayi Cheng > --- > Documentation/devicetree/bindings/mtd/mtk_nor.txt | 25 +++++++++++++++++++++++ > 1 file changed, 25 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mtd/mtk_nor.txt > > diff --git a/Documentation/devicetree/bindings/mtd/mtk_nor.txt b/Documentation/devicetree/bindings/mtd/mtk_nor.txt > new file mode 100644 > index 0000000..0eca0cd > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/mtk_nor.txt > @@ -0,0 +1,25 @@ > +* MTD SPI nor driver for MTK MT81xx (and similar) serial flash controller > + > +MTK MT81xx serial flash controller is designed for serial Flash device. > +It supports one Flash device with signal mode, dual mode and quad mode. > + > +Required properties: > +- compatible: should be "mediatek,mt8173-nor"; > +- reg: physical base address and length of the controller's register > +- clocks: spi nor source clock > +- clock-names: "spi_clk", "axi_clk", "mux_clk", "sf_clk" > + > +See Documentation/devicetree/bindings/clock/clock-bindings.txt > +and Documentation/mtd/spi-nor.txt for details. > + > +Example: > +nor_flash: nor@1100d000 { > + compatible = "mediatek,mt8173-nor"; > + reg = <0 0x1100d000 0 0xe0>; > + clocks = <&pericfg CLK_PERI_SPI>, > + <&topckgen CLK_TOP_AXI_SEL>, > + <&topckgen CLK_TOP_UNIVPLL2_D8>, > + <&topckgen CLK_TOP_SPINFI_IFR_SEL>; > + clock-names = "spi_clk", "axi_clk", "mux_clk", "sf_clk"; > +}; I understand that for now, you only support a single flash, and you don't need any extra flash-specific DT properties, but in the interest of being more generic and more in-line with other drivers, can you include: * #addres-cells (= <1>) and #size-cells (= <0>) properties * sub-node(s) representing the flash; reference [1], and there's a good example in a recent submission [2] So I'd expect something like: nor_flash: nor@1100d000 { compatible = "mediatek,mt8173-nor"; ... #address-cells = <1>; #size-cells = <0>; flash@0 { compatible = "jedec,spi-nor"; reg = <0>; ... }; }; This patch is also relevant [3] (hopefully I'll get to merge that one soon); you'll want to use the sub-node (not the main node) when initializing the flash device. I think maybe we'll want to codify some of this in a "SPI NOR controller" document, so we can make sure more developers follow this when designing their binding. Brian [1] https://www.kernel.org/doc/Documentation/devicetree/bindings/mtd/jedec,spi-nor.txt [2] http://lists.infradead.org/pipermail/linux-mtd/2015-August/061439.html [3] http://lists.infradead.org/pipermail/linux-mtd/2015-September/061637.html -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html