aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/powerpc/dts-bindings/mtd-physmap.txt42
1 files changed, 26 insertions, 16 deletions
diff --git a/Documentation/powerpc/dts-bindings/mtd-physmap.txt b/Documentation/powerpc/dts-bindings/mtd-physmap.txt
index 667c9bde8699..80152cb567d9 100644
--- a/Documentation/powerpc/dts-bindings/mtd-physmap.txt
+++ b/Documentation/powerpc/dts-bindings/mtd-physmap.txt
@@ -1,18 +1,19 @@
1CFI or JEDEC memory-mapped NOR flash 1CFI or JEDEC memory-mapped NOR flash, MTD-RAM (NVRAM...)
2 2
3Flash chips (Memory Technology Devices) are often used for solid state 3Flash chips (Memory Technology Devices) are often used for solid state
4file systems on embedded devices. 4file systems on embedded devices.
5 5
6 - compatible : should contain the specific model of flash chip(s) 6 - compatible : should contain the specific model of mtd chip(s)
7 used, if known, followed by either "cfi-flash" or "jedec-flash" 7 used, if known, followed by either "cfi-flash", "jedec-flash"
8 - reg : Address range(s) of the flash chip(s) 8 or "mtd-ram".
9 - reg : Address range(s) of the mtd chip(s)
9 It's possible to (optionally) define multiple "reg" tuples so that 10 It's possible to (optionally) define multiple "reg" tuples so that
10 non-identical NOR chips can be described in one flash node. 11 non-identical chips can be described in one node.
11 - bank-width : Width (in bytes) of the flash bank. Equal to the 12 - bank-width : Width (in bytes) of the bank. Equal to the
12 device width times the number of interleaved chips. 13 device width times the number of interleaved chips.
13 - device-width : (optional) Width of a single flash chip. If 14 - device-width : (optional) Width of a single mtd chip. If
14 omitted, assumed to be equal to 'bank-width'. 15 omitted, assumed to be equal to 'bank-width'.
15 - #address-cells, #size-cells : Must be present if the flash has 16 - #address-cells, #size-cells : Must be present if the device has
16 sub-nodes representing partitions (see below). In this case 17 sub-nodes representing partitions (see below). In this case
17 both #address-cells and #size-cells must be equal to 1. 18 both #address-cells and #size-cells must be equal to 1.
18 19
@@ -22,24 +23,24 @@ are defined:
22 - vendor-id : Contains the flash chip's vendor id (1 byte). 23 - vendor-id : Contains the flash chip's vendor id (1 byte).
23 - device-id : Contains the flash chip's device id (1 byte). 24 - device-id : Contains the flash chip's device id (1 byte).
24 25
25In addition to the information on the flash bank itself, the 26In addition to the information on the mtd bank itself, the
26device tree may optionally contain additional information 27device tree may optionally contain additional information
27describing partitions of the flash address space. This can be 28describing partitions of the address space. This can be
28used on platforms which have strong conventions about which 29used on platforms which have strong conventions about which
29portions of the flash are used for what purposes, but which don't 30portions of a flash are used for what purposes, but which don't
30use an on-flash partition table such as RedBoot. 31use an on-flash partition table such as RedBoot.
31 32
32Each partition is represented as a sub-node of the flash device. 33Each partition is represented as a sub-node of the mtd device.
33Each node's name represents the name of the corresponding 34Each node's name represents the name of the corresponding
34partition of the flash device. 35partition of the mtd device.
35 36
36Flash partitions 37Flash partitions
37 - reg : The partition's offset and size within the flash bank. 38 - reg : The partition's offset and size within the mtd bank.
38 - label : (optional) The label / name for this flash partition. 39 - label : (optional) The label / name for this partition.
39 If omitted, the label is taken from the node name (excluding 40 If omitted, the label is taken from the node name (excluding
40 the unit address). 41 the unit address).
41 - read-only : (optional) This parameter, if present, is a hint to 42 - read-only : (optional) This parameter, if present, is a hint to
42 Linux that this flash partition should only be mounted 43 Linux that this partition should only be mounted
43 read-only. This is usually used for flash partitions 44 read-only. This is usually used for flash partitions
44 containing early-boot firmware images or data which should not 45 containing early-boot firmware images or data which should not
45 be clobbered. 46 be clobbered.
@@ -78,3 +79,12 @@ Here an example with multiple "reg" tuples:
78 reg = <0 0x04000000>; 79 reg = <0 0x04000000>;
79 }; 80 };
80 }; 81 };
82
83An example using SRAM:
84
85 sram@2,0 {
86 compatible = "samsung,k6f1616u6a", "mtd-ram";
87 reg = <2 0 0x00200000>;
88 bank-width = <2>;
89 };
90