[PATCH v3 02/10] Documentation: devicetree: add binding doc for Broadcom NAND controller

Brian Norris
2015-05-06T18:01:23Z

Signed-off-by: Brian Norris <computersforpeace@gmail.com>
---
.../devicetree/bindings/mtd/brcm,brcmstb-nand.txt | 110 +++++++++++++++++++++
1 file changed, 110 insertions(+)
create mode 100644 Documentation/devicetree/bindings/mtd/brcm,brcmstb-nand.txt

diff --git a/Documentation/devicetree/bindings/mtd/brcm,brcmstb-nand.txt b/Documentation/devicetree/bindings/mtd/brcm,brcmstb-nand.txt
new file mode 100644
index 000000000000..662c857e74fe
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+++ b/Documentation/devicetree/bindings/mtd/brcm,brcmstb-nand.txt
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+* 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-v6.1
+ 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>;
+ };
+ };
+};
--
1.9.1