151 строка
6.7 KiB
Plaintext
151 строка
6.7 KiB
Plaintext
* 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 : May contain an SoC-specific compatibility string (see below)
|
|
to account for any SoC-specific hardware bits that may be
|
|
added on top of the base core controller.
|
|
In addition, must contain compatibility information about
|
|
the core NAND controller, of the following form:
|
|
"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", if broken out as
|
|
individual interrupts.
|
|
May be "nand", if the SoC has the individual NAND
|
|
interrupts multiplexed behind another custom piece of
|
|
hardware
|
|
- 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
|
|
|
|
-- Additonal SoC-specific NAND controller properties --
|
|
|
|
The NAND controller is integrated differently on the variety of SoCs on which it
|
|
is found. Part of this integration involves providing status and enable bits
|
|
with which to control the 8 exposed NAND interrupts, as well as hardware for
|
|
configuring the endianness of the data bus. On some SoCs, these features are
|
|
handled via standard, modular components (e.g., their interrupts look like a
|
|
normal IRQ chip), but on others, they are controlled in unique and interesting
|
|
ways, sometimes with registers that lump multiple NAND-related functions
|
|
together. The former case can be described simply by the standard interrupts
|
|
properties in the main controller node. But for the latter exceptional cases,
|
|
we define additional 'compatible' properties and associated register resources within the NAND controller node above.
|
|
|
|
- compatible: Can be one of several SoC-specific strings. Each SoC may have
|
|
different requirements for its additional properties, as described below each
|
|
bullet point below.
|
|
|
|
* "brcm,nand-bcm63138"
|
|
- reg: (required) the 'NAND_INT_BASE' register range, with separate status
|
|
and enable registers
|
|
- reg-names: (required) "nand-int-base"
|
|
|
|
* "brcm,nand-iproc"
|
|
- reg: (required) the "IDM" register range, for interrupt enable and APB
|
|
bus access endianness configuration, and the "EXT" register range,
|
|
for interrupt status/ack.
|
|
- reg-names: (required) a list of the names corresponding to the previous
|
|
register ranges. Should contain "iproc-idm" and "iproc-ext".
|
|
|
|
|
|
* 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>;
|
|
};
|
|
};
|
|
};
|