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
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Define register bitfields to be used to control multiplexers. The parent
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device tree node must be a syscon node to provide register access.
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Required properties:
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- compatible : "mmio-mux"
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- #mux-control-cells : <1>
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- mux-reg-masks : an array of register offset and pre-shifted bitfield mask
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pairs, each describing a single mux control.
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* Standard mux-controller bindings as decribed in mux-controller.txt
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Optional properties:
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- idle-states : if present, the state the muxes will have when idle. The
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special state MUX_IDLE_AS_IS is the default.
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The multiplexer state of each multiplexer is defined as the value of the
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bitfield described by the corresponding register offset and bitfield mask pair
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in the mux-reg-masks array, accessed through the parent syscon.
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Example:
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syscon {
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compatible = "syscon";
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mux: mux-controller {
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compatible = "mmio-mux";
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#mux-control-cells = <1>;
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mux-reg-masks = <0x3 0x30>, /* 0: reg 0x3, bits 5:4 */
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<0x3 0x40>, /* 1: reg 0x3, bit 6 */
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idle-states = <MUX_IDLE_AS_IS>, <0>;
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};
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};
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video-mux {
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compatible = "video-mux";
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mux-controls = <&mux 0>;
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ports {
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/* inputs 0..3 */
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port@0 {
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reg = <0>;
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};
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port@1 {
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reg = <1>;
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};
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port@2 {
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reg = <2>;
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};
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port@3 {
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reg = <3>;
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};
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/* output */
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port@4 {
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reg = <4>;
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};
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};
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};
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