From mboxrd@z Thu Jan 1 00:00:00 1970 From: Rob Herring Subject: Re: [PATCH v2 1/5] dt-bindings: mtd: add Marvell NAND controller documentation Date: Wed, 20 Dec 2017 15:05:11 -0600 Message-ID: <20171220210511.ty2e7mkiktvn4een@rob-hp-laptop> References: <20171219132942.27433-1-miquel.raynal@free-electrons.com> <20171219132942.27433-2-miquel.raynal@free-electrons.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20171219132942.27433-2-miquel.raynal-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org> Sender: devicetree-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Miquel Raynal Cc: David Woodhouse , Brian Norris , Boris Brezillon , Marek Vasut , Richard Weinberger , Cyrille Pitchen , Mark Rutland , Jason Cooper , Andrew Lunn , Gregory Clement , Sebastian Hesselbarth , Russell King , Daniel Mack , Haojian Zhuang , Robert Jarzmik , Eric Miao , Catalin Marinas , Will Deacon , Ezequiel List-Id: devicetree@vger.kernel.org On Tue, Dec 19, 2017 at 02:29:38PM +0100, Miquel Raynal wrote: > Document the legacy and the new bindings for Marvell NAND controller. > > The pxa3xx_nand.c driver does only support legacy bindings, which are > incomplete and inaccurate. A rework of this controller (called > marvell_nand.c) does support both. > > Signed-off-by: Miquel Raynal > --- > .../devicetree/bindings/mtd/marvell-nand.txt | 123 +++++++++++++++++++++ > 1 file changed, 123 insertions(+) > create mode 100644 Documentation/devicetree/bindings/mtd/marvell-nand.txt > > diff --git a/Documentation/devicetree/bindings/mtd/marvell-nand.txt b/Documentation/devicetree/bindings/mtd/marvell-nand.txt > new file mode 100644 > index 000000000000..aa6a1ed045b2 > --- /dev/null > +++ b/Documentation/devicetree/bindings/mtd/marvell-nand.txt > @@ -0,0 +1,123 @@ > +Marvell NAND Flash Controller (NFC) > + > +Required properties: > +- compatible: can be one of the following: > + * "marvell,armada-8k-nand-controller" > + * "marvell,armada370-nand-controller" > + * "marvell,pxa3xx-nand-controller" > + * "marvell,armada-8k-nand" (deprecated) > + * "marvell,armada370-nand" (deprecated) > + * "marvell,pxa3xx-nand" (deprecated) > + Compatibles marked deprecated support only the old bindings described > + at the bottom. > +- reg: NAND flash controller memory area. > +- #address-cells: shall be set to 1. Encode the NAND CS. > +- #size-cells: shall be set to 0. > +- interrupts: shall define the NAND controller interrupt. > +- clocks: shall reference the NAND controller clock. > +- marvell,system-controller: Set to retrieve the syscon node that handles > + NAND controller related registers (only required with the > + "marvell,armada-8k-nand[-controller]" compatibles). > + > +Optional properties: > +- label: see partition.txt. New platforms shall omit this property. > +- dmas: shall reference DMA channel associated to the NAND controller. > + This property is only used with "marvell,pxa3xx-nand[-controller]" > + compatible strings. > +- dma-names: shall be "rxtx". > + This property is only used with "marvell,pxa3xx-nand[-controller]" > + compatible strings. > + > +Optional children nodes: > +Children nodes represent the available NAND chips. > + > +Required properties: > +- reg: shall contain the native Chip Select ids (0-3) > +- marvell,rb: shall contain the native Ready/Busy ids (0-1) We already have at least 2 other ,rb properties. Let's not add a 3rd and make a common one instead. > + > +Optional properties: > +- marvell,nand-keep-config: orders the driver not to take the timings > + from the core and leaving them completely untouched. Bootloader > + timings will then be used. > +- label: MTD name. > +- nand-on-flash-bbt: see nand.txt. > +- nand-ecc-mode: see nand.txt. Will use hardware ECC if not specified. > +- nand-ecc-algo: see nand.txt. This property may be added when using > + hardware ECC for clarification but will be ignored by the driver > + because ECC mode is chosen depending on the page size and the strength > + required by the NAND chip. This value may be overwritten with > + nand-ecc-strength property. If not used, then drop it. > +- nand-ecc-strength: see nand.txt. > +- nand-ecc-step-size: see nand.txt. This has no effect and will be > + ignored by the driver when using hardware ECC because Marvell's NAND > + flash controller does use fixed strength (1-bit for Hamming, 16-bit > + for BCH), so the step size will shrink or grow in order to fit the > + required strength. Step sizes are not completely random for all and > + follow certain patterns described in AN-379, "Marvell SoC NFC ECC". Same here. > + > +See Documentation/devicetree/bindings/mtd/nand.txt for more details on > +generic bindings. > + > + > +Example: > +nand_controller: nand-controller@d0000 { > + compatible = "marvell,armada370-nand-controller"; > + reg = <0xd0000 0x54>; > + #address-cells = <1>; > + #size-cells = <0>; > + interrupts = ; > + clocks = <&coredivclk 0>; > + > + nand@0 { > + reg = <0>; > + label = "main-storage"; > + marvell,rb = <0>; > + nand-ecc-mode = "hw"; > + marvell,nand-keep-config; > + nand-on-flash-bbt; > + nand-ecc-strength = <4>; > + nand-ecc-step-size = <512>; > + > + partitions { > + compatible = "fixed-partitions"; > + #address-cells = <1>; > + #size-cells = <1>; > + > + partition@0 { > + label = "Rootfs"; > + reg = <0x00000000 0x40000000>; > + }; > + }; > + }; > +}; > + > + > +Note on legacy bindings: One can find, in not-updated device trees, > +bindings slightly differents than described above with other properties s/differents/different/ > +described below as well as the partitions node at the root of a so > +called "nand" node (without clear controller/chip separation). > + > +Legacy properties: > +- marvell,nand-enable-arbiter: To enable the arbiter, all boards blindly > + used it, this bit was set by the bootloader for many boards and even if > + it is marked reserved in several datasheets, it might be needed to set > + it (otherwise it is harmless) so whether or not this property is set, > + the bit is selected by the driver. > +- num-cs: Number of chip-select lines to use, all boards blindly set 1 > + to this and for a reason, other values would have failed. The value of > + this property is ignored. > + > +Example: > + > + nand0: nand@43100000 { > + compatible = "marvell,pxa3xx-nand"; > + reg = <0x43100000 90>; > + interrupts = <45>; > + dmas = <&pdma 97 0>; > + dma-names = "rxtx"; > + #address-cells = <1>; > + marvell,nand-keep-config; > + marvell,nand-enable-arbiter; > + num-cs = <1>; > + /* Partitions (optional) */ > + }; > -- > 2.11.0 > -- 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