Device-Tree bindings for LVDS Display Bridge (ldb)
LVDS Display Bridge
===================
The LVDS Display Bridge device tree node contains up to two lvds-channel
nodes describing each of the two LVDS encoder channels of the bridge.
Required properties:
- #address-cells : should be <1>
- #size-cells : should be <0>
- compatible : should be "fsl,imx53-ldb" or "fsl,imx6q-ldb".
Both LDB versions are similar, but i.MX6 has an additional
multiplexer in the front to select any of the four IPU display
interfaces as input for each LVDS channel.
- gpr : should be <&gpr> on i.MX53 and i.MX6q.
The phandle points to the iomuxc-gpr region containing the LVDS
control register.
- clocks, clock-names : phandles to the LDB divider and selector clocks and to
the display interface selector clocks, as described in
Documentation/devicetree/bindings/clock/clock-bindings.txt
The following clocks are expected on i.MX53:
"di0_pll" - LDB LVDS channel 0 mux
"di1_pll" - LDB LVDS channel 1 mux
"di0" - LDB LVDS channel 0 gate
"di1" - LDB LVDS channel 1 gate
"di0_sel" - IPU1 DI0 mux
"di1_sel" - IPU1 DI1 mux
On i.MX6q the following additional clocks are needed:
"di2_sel" - IPU2 DI0 mux
"di3_sel" - IPU2 DI1 mux
The needed clock numbers for each are documented in
Documentation/devicetree/bindings/clock/imx5-clock.yaml, and in
Documentation/devicetree/bindings/clock/imx6q-clock.yaml.
Optional properties:
- pinctrl-names : should be "default" on i.MX53, not used on i.MX6q
- pinctrl-0 : a phandle pointing to LVDS pin settings on i.MX53,
not used on i.MX6q
- fsl,dual-channel : boolean. if it exists, only LVDS channel 0 should
be configured - one input will be distributed on both outputs in dual
channel mode
LVDS Channel
============
Each LVDS Channel has to contain either an of graph link to a panel device node
or a display-timings node that describes the video timings for the connected
LVDS display as well as the fsl,data-mapping and fsl,data-width properties.
Required properties:
- reg : should be <0> or <1>
- port: Input and output port nodes with endpoint definitions as defined in
Documentation/devicetree/bindings/graph.txt.
On i.MX5, the internal two-input-multiplexer is used. Due to hardware
limitations, only one input port (port@[0,1]) can be used for each channel
(lvds-channel@[0,1], respectively).
On i.MX6, there should be four input ports (port@[0-3]) that correspond
to the four LVDS multiplexer inputs.
A single output port (port@2 on i.MX5, port@4 on i.MX6) must be connected
to a panel input port. Optionally, the output port can be left out if
display-timings are used instead.
Optional properties (required if display-timings are used):
- ddc-i2c-bus: phandle of an I2C controller used for DDC EDID probing
- display-timings : A node that describes the display timings as defined in
Documentation/devicetree/bindings/display/panel/display-timing.txt.
- fsl,data-mapping : should be "spwg" or "jeida"
This describes how the color bits are laid out in the
serialized LVDS signal.
- fsl,data-width : should be <18> or <24>
example:
gpr: iomuxc-gpr@53fa8000 {
/* ... */
};
ldb: ldb@53fa8008 {
#address-cells = <1>;
#size-cells = <0>;
compatible = "fsl,imx53-ldb";
gpr = <&gpr>;
clocks = <&clks IMX5_CLK_LDB_DI0_SEL>,
<&clks IMX5_CLK_LDB_DI1_SEL>,
<&clks IMX5_CLK_IPU_DI0_SEL>,
<&clks IMX5_CLK_IPU_DI1_SEL>,
<&clks IMX5_CLK_LDB_DI0_GATE>,
<&clks IMX5_CLK_LDB_DI1_GATE>;
clock-names = "di0_pll", "di1_pll",
"di0_sel", "di1_sel",
"di0", "di1";
/* Using an of-graph endpoint link to connect the panel */
lvds-channel@0 {
#address-cells = <1>;
#size-cells = <0>;
reg = <0>;
port@0 {
reg = <0>;
lvds0_in: endpoint {
remote-endpoint = <&ipu_di0_lvds0>;
};
};
port@2 {
reg = <2>;
lvds0_out: endpoint {
remote-endpoint = <&panel_in>;
};
};
};
/* Using display-timings and fsl,data-mapping/width instead */
lvds-channel@1 {
#address-cells = <1>;
#size-cells = <0>;
reg = <1>;
fsl,data-mapping = "spwg";
fsl,data-width = <24>;
display-timings {
/* ... */
};
port@1 {
reg = <1>;
lvds1_in: endpoint {
remote-endpoint = <&ipu_di1_lvds1>;
};
};
};
};
panel: lvds-panel {
/* ... */
port {
panel_in: endpoint {
remote-endpoint = <&lvds0_out>;
};
};
};
