diff options
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/dts-format.txt | 34 |
1 files changed, 23 insertions, 11 deletions
diff --git a/Documentation/dts-format.txt b/Documentation/dts-format.txt index eae8b76..41741df 100644 --- a/Documentation/dts-format.txt +++ b/Documentation/dts-format.txt @@ -29,18 +29,28 @@ except for properties with empty (zero length) value which have the form: [label:] property-name; -Property values may be defined as an array of 32-bit integer cells, as -NUL-terminated strings, as bytestrings or a combination of these. +Property values may be defined as an array of 8, 16, 32, or 64-bit integer +elements, as NUL-terminated strings, as bytestrings or a combination of these. -* Arrays of cells are represented by angle brackets surrounding a - space separated list of C-style integers or character literals. +* Arrays are represented by angle brackets surrounding a space separated list + of C-style integers or character literals. Array elements default to 32-bits + in size. An array of 32-bit elements is also known as a cell list or a list + of cells. A cell being an unsigned 32-bit integer. e.g. interrupts = <17 0xc>; -* A 64-bit value is represented with two 32-bit cells. +* A 64-bit value can be represented with two 32-bit elements. e.g. clock-frequency = <0x00000001 0x00000000>; +* The storage size of an element can be changed using the /bits/ prefix. The + /bits/ prefix allows for the creation of 8, 16, 32, and 64-bit elements. + The resulting array will not be padded to a multiple of the default 32-bit + element size. + + e.g. interrupts = /bits/ 8 <17 0xc>; + e.g. clock-frequency = /bits/ 64 <0x0000000100000000>; + * A NUL-terminated string value is represented using double quotes (the property value is considered to include the terminating NUL character). @@ -59,19 +69,20 @@ NUL-terminated strings, as bytestrings or a combination of these. e.g. compatible = "ns16550", "ns8250"; example = <0xf00f0000 19>, "a strange property format"; -* In a cell array a reference to another node will be expanded to that - node's phandle. References may by '&' followed by a node's label: +* In an array a reference to another node will be expanded to that node's + phandle. References may by '&' followed by a node's label: e.g. interrupt-parent = < &mpic >; or they may be '&' followed by a node's full path in braces: e.g. interrupt-parent = < &{/soc/interrupt-controller@40000} >; + References are only permitted in arrays that have an element size of + 32-bits. -* Outside a cell array, a reference to another node will be expanded - to that node's full path. +* Outside an array, a reference to another node will be expanded to that + node's full path. e.g. ethernet0 = &EMAC0; * Labels may also appear before or after any component of a property - value, or between cells of a cell array, or between bytes of a - bytestring. + value, or between elements of an array, or between bytes of a bytestring. e.g. reg = reglabel: <0 sizelabel: 0x1000000>; e.g. prop = [ab cd ef byte4: 00 ff fe]; e.g. str = start: "string value" end: ; @@ -108,3 +119,4 @@ Version 1 DTS files have the overall layout: -- David Gibson <david@gibson.dropbear.id.au> -- Yoder Stuart <stuart.yoder@freescale.com> + -- Anton Staaf <robotboy@chromium.org> |