mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 13:51:44 +00:00
5dc75a2d93
This adds device tree binding documentation for mmio-based syscon multiplexers controlled by a bitfields in a syscon register range. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Acked-by: Rob Herring <robh@kernel.org> Signed-off-by: Peter Rosin <peda@axentia.se> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
61 lines
1.4 KiB
Plaintext
61 lines
1.4 KiB
Plaintext
MMIO register bitfield-based multiplexer controller bindings
|
|
|
|
Define register bitfields to be used to control multiplexers. The parent
|
|
device tree node must be a syscon node to provide register access.
|
|
|
|
Required properties:
|
|
- compatible : "mmio-mux"
|
|
- #mux-control-cells : <1>
|
|
- mux-reg-masks : an array of register offset and pre-shifted bitfield mask
|
|
pairs, each describing a single mux control.
|
|
* Standard mux-controller bindings as decribed in mux-controller.txt
|
|
|
|
Optional properties:
|
|
- idle-states : if present, the state the muxes will have when idle. The
|
|
special state MUX_IDLE_AS_IS is the default.
|
|
|
|
The multiplexer state of each multiplexer is defined as the value of the
|
|
bitfield described by the corresponding register offset and bitfield mask pair
|
|
in the mux-reg-masks array, accessed through the parent syscon.
|
|
|
|
Example:
|
|
|
|
syscon {
|
|
compatible = "syscon";
|
|
|
|
mux: mux-controller {
|
|
compatible = "mmio-mux";
|
|
#mux-control-cells = <1>;
|
|
|
|
mux-reg-masks = <0x3 0x30>, /* 0: reg 0x3, bits 5:4 */
|
|
<0x3 0x40>, /* 1: reg 0x3, bit 6 */
|
|
idle-states = <MUX_IDLE_AS_IS>, <0>;
|
|
};
|
|
};
|
|
|
|
video-mux {
|
|
compatible = "video-mux";
|
|
mux-controls = <&mux 0>;
|
|
|
|
ports {
|
|
/* inputs 0..3 */
|
|
port@0 {
|
|
reg = <0>;
|
|
};
|
|
port@1 {
|
|
reg = <1>;
|
|
};
|
|
port@2 {
|
|
reg = <2>;
|
|
};
|
|
port@3 {
|
|
reg = <3>;
|
|
};
|
|
|
|
/* output */
|
|
port@4 {
|
|
reg = <4>;
|
|
};
|
|
};
|
|
};
|