From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-qt0-f196.google.com ([209.85.216.196]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1fviNL-0004WT-FX for linux-mtd@lists.infradead.org; Fri, 31 Aug 2018 12:18:08 +0000 Received: by mail-qt0-f196.google.com with SMTP id m13-v6so14271162qth.1 for ; Fri, 31 Aug 2018 05:17:54 -0700 (PDT) Date: Fri, 31 Aug 2018 08:17:51 -0400 From: Rob Herring To: Ricardo Ribalda Delgado Cc: David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Zhouyang Jia , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH 8/8] dt-binding: mtd: Document gpio-addr-flash Message-ID: <20180831121751.GA22256@bogus> References: <20180821143152.32293-1-ricardo.ribalda@gmail.com> <20180821143152.32293-9-ricardo.ribalda@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180821143152.32293-9-ricardo.ribalda@gmail.com> List-Id: Linux MTD discussion mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Aug 21, 2018 at 04:31:52PM +0200, Ricardo Ribalda Delgado wrote: > Add documentation for gpio-addr-flash. This binding allow creating > flash devices that are paged using GPIOs. > > Cc: devicetree@vger.kernel.org > Signed-off-by: Ricardo Ribalda Delgado > --- > .../bindings/mtd/gpio-addr-flash.txt | 46 +++++++++++++++++++ > 1 file changed, 46 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt > > diff --git a/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt > new file mode 100644 > index 000000000000..4279e8cad09b > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/gpio-addr-flash.txt > @@ -0,0 +1,46 @@ > +Memory Mapped flash with some address lines addressed using GPIOs That's ugly... > + > +Handle the case where a flash device is mostly addressed using physical > +line and supplemented by GPIOs. This way you can hook up say a 8MiB flash > +to a 2MiB memory range and use the GPIOs to select a particular range. > + > + - compatible : "cfi-gpio-addr-flash" Why a new compatible? Shouldn't just adding some address gpios to an existing flash device binding be sufficient? > + - reg : Address range of the mtd chip that is memory mapped, this is, > + on the previous example 2MiB. > + - bank-width : Width (in bytes) of the bank. Equal to the > + device width times the number of interleaved chips. > + - probe-type : (optional) "cfi_probe", "jedec_probe". How the mtd chip > + is going to be probed. If omitted, assumed to be equal to "cfi_probe". > + - #address-cells, #size-cells : Must be present if the device has > + sub-nodes representing partitions (see below). In this case > + both #address-cells and #size-cells must be equal to 1. > + > +The device tree may optionally contain sub-nodes describing partitions of the > +address space. See partition.txt for more detail. > + > +Example: > + > + cfi_flash_0: cfi_flash { > + #address-cells = <1>; > + #size-cells = <1>; > + compatible = "cfi-gpio-addr-flash"; > + bank-width = <2>; > + reg = < 0x00300000 0x00200000 >; > + gpios = <&gpio_0 3 0>, <&gpio_0 4 0>; > + partition@0 { > + reg = < 0x0 0x200000 >; > + label = "Golden Bitstream"; > + }; > + partition@200000 { > + reg = < 0x200000 0x200000 >; > + label = "User Bitstream"; > + }; > + partition@400000 { > + reg = < 0x400000 0x200000 >; > + label = "V4L Controls"; > + }; > + partition@600000 { > + reg = < 0x600000 0x200000 >; > + label = "Production Data"; > + }; > + } ; > -- > 2.18.0 >