1 # SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
2 %YAML 1.2
3 ---
4 $id: http://devicetree.org/schemas/mtd/raw-nand-chip.yaml#
5 $schema: http://devicetree.org/meta-schemas/core.yaml#
6
7 title: Raw NAND Chip Common Properties
8
9 maintainers:
10 - Miquel Raynal <miquel.raynal@bootlin.com>
11
12 allOf:
13 - $ref: nand-chip.yaml#
14
15 description: |
16 The ECC strength and ECC step size properties define the user
17 desires in terms of correction capability of a controller. Together,
18 they request the ECC engine to correct {strength} bit errors per
19 {size} bytes for a particular raw NAND chip.
20
21 The interpretation of these parameters is implementation-defined, so
22 not all implementations must support all possible
23 combinations. However, implementations are encouraged to further
24 specify the value(s) they support.
25
26 properties:
27 $nodename:
28 pattern: "^nand@[a-f0-9]$"
29
30 reg:
31 description:
32 Contains the chip-select IDs.
33
34 nand-ecc-placement:
35 description:
36 Location of the ECC bytes. This location is unknown by default
37 but can be explicitly set to "oob", if all ECC bytes are
38 known to be stored in the OOB area, or "interleaved" if ECC
39 bytes will be interleaved with regular data in the main area.
40 $ref: /schemas/types.yaml#/definitions/string
41 enum: [ oob, interleaved ]
42 deprecated: true
43
44 nand-ecc-mode:
45 description:
46 Legacy ECC configuration mixing the ECC engine choice and
47 configuration.
48 $ref: /schemas/types.yaml#/definitions/string
49 enum: [none, soft, soft_bch, hw, hw_syndrome, on-die]
50 deprecated: true
51
52 nand-bus-width:
53 description:
54 Bus width to the NAND chip
55 $ref: /schemas/types.yaml#/definitions/uint32
56 enum: [8, 16]
57 default: 8
58
59 nand-on-flash-bbt:
60 description:
61 With this property, the OS will search the device for a Bad
62 Block Table (BBT). If not found, it will create one, reserve
63 a few blocks at the end of the device to store it and update
64 it as the device ages. Otherwise, the out-of-band area of a
65 few pages of all the blocks will be scanned at boot time to
66 find Bad Block Markers (BBM). These markers will help to
67 build a volatile BBT in RAM.
68 $ref: /schemas/types.yaml#/definitions/flag
69
70 nand-ecc-maximize:
71 description:
72 Whether or not the ECC strength should be maximized. The
73 maximum ECC strength is both controller and chip
74 dependent. The ECC engine has to select the ECC config
75 providing the best strength and taking the OOB area size
76 constraint into account. This is particularly useful when
77 only the in-band area is used by the upper layers, and you
78 want to make your NAND as reliable as possible.
79 $ref: /schemas/types.yaml#/definitions/flag
80
81 nand-is-boot-medium:
82 description:
83 Whether or not the NAND chip is a boot medium. Drivers might
84 use this information to select ECC algorithms supported by
85 the boot ROM or similar restrictions.
86 $ref: /schemas/types.yaml#/definitions/flag
87
88 nand-rb:
89 description:
90 Contains the native Ready/Busy IDs.
91 $ref: /schemas/types.yaml#/definitions/uint32-array
92
93 rb-gpios:
94 description:
95 Contains one or more GPIO descriptor (the numper of descriptor
96 depends on the number of R/B pins exposed by the flash) for the
97 Ready/Busy pins. Active state refers to the NAND ready state and
98 should be set to GPIOD_ACTIVE_HIGH unless the signal is inverted.
99
100 wp-gpios:
101 description:
102 Contains one GPIO descriptor for the Write Protect pin.
103 Active state refers to the NAND Write Protect state and should be
104 set to GPIOD_ACTIVE_LOW unless the signal is inverted.
105 maxItems: 1
106
107 required:
108 - reg
109
110 # This is a generic file other binding inherit from and extend
111 additionalProperties: true
Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.