Re: [PATCH 2/3] Documentation: devicetree: add binding doc for Broadcom NAND controller

[Florian Fainelli <f.fainelli@gmail.com>]

On 06/03/15 17:18, Brian Norris wrote:
> Signed-off-by: Brian Norris <computersforpeace@gmail.com>

Reviewed-by: Florian Fainelli <f.fainelli@gmail.com>

> ---
>  .../devicetree/bindings/mtd/brcmstb_nand.txt       | 109 +++++++++++++++++++++
>  1 file changed, 109 insertions(+)
>  create mode 100644 Documentation/devicetree/bindings/mtd/brcmstb_nand.txt
> 
> diff --git a/Documentation/devicetree/bindings/mtd/brcmstb_nand.txt b/Documentation/devicetree/bindings/mtd/brcmstb_nand.txt
> new file mode 100644
> index 000000000000..933d44943cbb
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mtd/brcmstb_nand.txt
> @@ -0,0 +1,109 @@
> +* Broadcom STB NAND Controller
> +
> +The Broadcom Set-Top Box NAND controller supports low-level access to raw NAND
> +flash chips. It has a memory-mapped register interface for both control
> +registers and for its data input/output buffer. On some SoCs, this controller is
> +paired with a custom DMA engine (inventively named "Flash DMA") which supports
> +basic PROGRAM and READ functions, among other features.
> +
> +This controller was originally designed for STB SoCs (BCM7xxx) but is now
> +available on a variety of Broadcom SoCs, including some BCM3xxx, BCM63xx, and
> +iProc/Cygnus. Its history includes several similar (but not fully register
> +compatible) versions.
> +
> +Required properties:
> +- compatible       : should contain "brcm,brcmnand" and an appropriate version
> +                      compatibility string, like "brcm,brcmnand-v7.0"
> +                      Possible values:
> +                         brcm,brcmnand-v4.0
> +                         brcm,brcmnand-v5.0
> +                         brcm,brcmnand-v6.0
> +                         brcm,brcmnand-v7.0
> +                         brcm,brcmnand-v7.1
> +                         brcm,brcmnand
> +- reg              : the register start and length for NAND register region.
> +                     (optional) Flash DMA register range (if present)
> +                     (optional) NAND flash cache range (if at non-standard offset)
> +- reg-names        : a list of the names corresponding to the previous register
> +                     ranges. Should contain "nand" and (optionally)
> +                     "flash-dma" and/or "nand-cache".
> +- interrupts       : The NAND CTLRDY interrupt and (if Flash DMA is available)
> +                     FLASH_DMA_DONE
> +- interrupt-names  : May be "nand_ctlrdy" or "flash_dma_done"
> +- interrupt-parent : See standard interrupt bindings
> +- #address-cells   : <1> - subnodes give the chip-select number
> +- #size-cells      : <0>
> +
> +Optional properties:
> +- brcm,nand-has-wp          : Some versions of this IP include a write-protect
> +                              (WP) control bit. It is always available on >=
> +                              v7.0. Use this property to describe the rare
> +                              earlier versions of this core that include WP
> +
> +* NAND chip-select
> +
> +Each controller (compatible: "brcm,brcmnand") may contain one or more subnodes
> +to represent enabled chip-selects which (may) contain NAND flash chips. Their
> +properties are as follows.
> +
> +Required properties:
> +- compatible                : should contain "brcm,nandcs"
> +- reg                       : a single integer representing the chip-select
> +                              number (e.g., 0, 1, 2, etc.)
> +- #address-cells            : see partition.txt
> +- #size-cells               : see partition.txt
> +- nand-ecc-strength         : see nand.txt
> +- nand-ecc-step-size        : must be 512 or 1024. See nand.txt
> +
> +Optional properties:
> +- nand-on-flash-bbt         : boolean, to enable the on-flash BBT for this
> +                              chip-select. See nand.txt
> +- brcm,nand-oob-sector-size : integer, to denote the spare area sector size
> +                              expected for the ECC layout in use. This size, in
> +                              addition to the strength and step-size,
> +                              determines how the hardware BCH engine will lay
> +                              out the parity bytes it stores on the flash.
> +                              This property can be automatically determined by
> +                              the flash geometry (particularly the NAND page
> +                              and OOB size) in many cases, but when booting
> +                              from NAND, the boot controller has only a limited
> +                              number of available options for its default ECC
> +                              layout.
> +
> +Each nandcs device node may optionally contain sub-nodes describing the flash
> +partition mapping. See partition.txt for more detail.
> +
> +Example:
> +
> +nand@f0442800 {
> +	compatible = "brcm,brcmnand-v7.0", "brcm,brcmnand";
> +	reg = <0xF0442800 0x600>,
> +	      <0xF0443000 0x100>;
> +	reg-names = "nand", "flash-dma";
> +	interrupt-parent = <&hif_intr2_intc>;
> +	interrupts = <24>, <4>;
> +
> +	#address-cells = <1>;
> +	#size-cells = <0>;
> +
> +	nandcs@1 {
> +		compatible = "brcm,nandcs";
> +		reg = <1>; // Chip select 1
> +		nand-on-flash-bbt;
> +		nand-ecc-strength = <12>;
> +		nand-ecc-step-size = <512>;
> +
> +		// Partitions
> +		#address-cells = <1>;  // <2>, for 64-bit offset
> +		#size-cells = <1>;     // <2>, for 64-bit length
> +		flash0.rootfs@0 {
> +			reg = <0 0x10000000>;
> +		};
> +		flash0@0 {
> +			reg = <0 0>; // MTDPART_SIZ_FULL
> +		};
> +		flash0.kernel@10000000 {
> +			reg = <0x10000000 0x400000>;
> +		};
> +	};
> +};
> 


-- 
Florian