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author | Thierry Reding <treding@nvidia.com> | 2013-12-02 16:22:49 +0100 |
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committer | Thierry Reding <treding@nvidia.com> | 2013-12-17 18:09:34 +0100 |
commit | 43394d2fc8f6776c8971ab09544a93359acbe88b (patch) | |
tree | 8ed4b8862bae263991382009f8eb16e66aa99382 /Documentation/devicetree | |
parent | a4d86e5e42f5ceea2a076735c887cc49a885a043 (diff) | |
download | op-kernel-dev-43394d2fc8f6776c8971ab09544a93359acbe88b.zip op-kernel-dev-43394d2fc8f6776c8971ab09544a93359acbe88b.tar.gz |
of: Add MIPI DSI bus device tree bindings
Document the device tree bindings for the MIPI DSI bus. The MIPI Display
Serial Interface specifies a serial bus and a protocol for communication
between a host and up to four peripherals.
Signed-off-by: Thierry Reding <treding@nvidia.com>
Diffstat (limited to 'Documentation/devicetree')
-rw-r--r-- | Documentation/devicetree/bindings/mipi/dsi/mipi-dsi-bus.txt | 98 |
1 files changed, 98 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/mipi/dsi/mipi-dsi-bus.txt b/Documentation/devicetree/bindings/mipi/dsi/mipi-dsi-bus.txt new file mode 100644 index 0000000..973c272 --- /dev/null +++ b/Documentation/devicetree/bindings/mipi/dsi/mipi-dsi-bus.txt @@ -0,0 +1,98 @@ +MIPI DSI (Display Serial Interface) busses +========================================== + +The MIPI Display Serial Interface specifies a serial bus and a protocol for +communication between a host and up to four peripherals. This document will +define the syntax used to represent a DSI bus in a device tree. + +This document describes DSI bus-specific properties only or defines existing +standard properties in the context of the DSI bus. + +Each DSI host provides a DSI bus. The DSI host controller's node contains a +set of properties that characterize the bus. Child nodes describe individual +peripherals on that bus. + +The following assumes that only a single peripheral is connected to a DSI +host. Experience shows that this is true for the large majority of setups. + +DSI host +-------- + +In addition to the standard properties and those defined by the parent bus of +a DSI host, the following properties apply to a node representing a DSI host. + +Required properties: +- #address-cells: The number of cells required to represent an address on the + bus. DSI peripherals are addressed using a 2-bit virtual channel number, so + a maximum of 4 devices can be addressed on a single bus. Hence the value of + this property should be 1. +- #size-cells: Should be 0. There are cases where it makes sense to use a + different value here. See below. + +DSI peripheral +-------------- + +Peripherals are represented as child nodes of the DSI host's node. Properties +described here apply to all DSI peripherals, but individual bindings may want +to define additional, device-specific properties. + +Required properties: +- reg: The virtual channel number of a DSI peripheral. Must be in the range + from 0 to 3. + +Some DSI peripherals respond to more than a single virtual channel. In that +case two alternative representations can be chosen: +- The reg property can take multiple entries, one for each virtual channel + that the peripheral responds to. +- If the virtual channels that a peripheral responds to are consecutive, the + #size-cells can be set to 1. The first cell of each entry in the reg + property is the number of the first virtual channel and the second cell is + the number of consecutive virtual channels. + +Example +------- + + dsi-host { + ... + + #address-cells = <1>; + #size-cells = <0>; + + /* peripheral responds to virtual channel 0 */ + peripheral@0 { + compatible = "..."; + reg = <0>; + }; + + ... + }; + + dsi-host { + ... + + #address-cells = <1>; + #size-cells = <0>; + + /* peripheral responds to virtual channels 0 and 2 */ + peripheral@0 { + compatible = "..."; + reg = <0, 2>; + }; + + ... + }; + + dsi-host { + ... + + #address-cells = <1>; + #size-cells = <1>; + + /* peripheral responds to virtual channels 1, 2 and 3 */ + peripheral@1 { + compatible = "..."; + reg = <1 3>; + }; + + ... + }; |