Re: [RFC 1/2] dt-bindings: mipi-dsi: Add info about peripherals with non-DSI control bus
From: Rob Herring <robh@kernel.org>
Date: 2017-12-06 21:39:36
Also in:
dri-devel, linux-arm-msm
On Tue, Dec 05, 2017 at 04:03:55PM +0530, Archit Taneja wrote:
quoted hunk ↗ jump to hunk
Add a section that describes dt-bindings for peripherals that support MIPI DSI, but have a different bus as the primary control bus. Add an example for such peripherals. Signed-off-by: Archit Taneja <redacted> --- .../devicetree/bindings/display/mipi-dsi-bus.txt | 75 ++++++++++++++++++++-- 1 file changed, 68 insertions(+), 7 deletions(-)diff --git a/Documentation/devicetree/bindings/display/mipi-dsi-bus.txt b/Documentation/devicetree/bindings/display/mipi-dsi-bus.txt index 973c27273772..77a7cec15f5b 100644 --- a/Documentation/devicetree/bindings/display/mipi-dsi-bus.txt +++ b/Documentation/devicetree/bindings/display/mipi-dsi-bus.txt@@ -16,7 +16,7 @@ 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.@@ -30,11 +30,15 @@ Required properties: 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. +Peripherals with DSI as control bus +------------------------------------ + +Peripherals with the DSI bus as the primary control path 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.
Are there any panels with no control bus? I've never seen one, but it should be possible if LVDS panels can power on without commands.
quoted hunk ↗ jump to hunk
Required properties: - reg: The virtual channel number of a DSI peripheral. Must be in the range@@ -49,9 +53,25 @@ case two alternative representations can be chosen: property is the number of the first virtual channel and the second cell is the number of consecutive virtual channels. -Example -------- +Peripherals with a different control bus +---------------------------------------- + +There are peripherals that have I2C/SPI (or some other non-DSI bus) as the +primary control bus, but are also connected to a DSI bus (mostly for the data +path). Connections between such peripherals and a DSI host can be represented +using the graph bindings [1], [2]. + +[1] Documentation/devicetree/bindings/graph.txt +[2] Documentation/devicetree/bindings/media/video-interfaces.txt +Examples +======== +- (1), (2) and (3) are examples of a DSI host and peripheral on the DSI bus + with different virtual channel configurations. +- (4) is an example of a peripheral on a I2C control bus connected with to + a DSI host using of-graph bindings. + +1) dsi-host { ...@@ -67,6 +87,7 @@ Example ... }; +2) dsi-host { ...@@ -82,6 +103,7 @@ Example ... }; +3) dsi-host { ...@@ -96,3 +118,42 @@ Example ... }; + +4) + i2c-host { + ... + + dsi-bridge@35 { + compatible = "..."; + reg = <0x35>; + + ports { + #address-cells = <1>; + #size-cells = <0>; + + ... + + port@0 {
Drop unit-address and #*-cells.
+ bridge_mipi_in: endpoint {
+ remote-endpoint = <&host_mipi_out>;
+ };
+ };
+ };
+ };
+ };
+
+ dsi-host {
+ ...
+
+ ports {
+ #address-cells = <1>;
+ #size-cells = <0>;
+ ...
+
+ port@0 {Drop unit-address and #*-cells.
+ host_mipi_out: endpoint {
+ remote-endpoint = <&bridge_mipi_in>;
+ };
+ };
+ };
+ };
--
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