On 2019-02-28 14:30, Pankaj Bansal wrote:
> This adds device tree binding documentation for generic register based
> multiplexer controlled by a bitfields in a parent device's register range.
>
> since MMIO mux is a special case of generic register based mux, the
> MMIO mux bindings have been subsumed in these bindings.
>
> Signed-off-by: Pankaj Bansal <pankaj.bansal@xxxxxxx>
> ---
>
> Notes:
> V5:
> - Subsume the mmio-mux.txt bindings in reg-mux.txt
> V4:
> - No change
> V3:
> - Added the patch in series with the driver patch
> - Fixed the node value out of bitfield error
> - removed the "parent register r/w functions" line
> V2:
> - Removed syscon reference from txt file
> - Removed loading zeroes from hex numbers
> - Fixed the depth of dts nodes
> - fixed minor formatting errors
>
> .../devicetree/bindings/mux/mmio-mux.txt | 60 --------
> .../devicetree/bindings/mux/reg-mux.txt | 128 +++++++++++++++++
> 2 files changed, 128 insertions(+), 60 deletions(-)
>
> diff --git a/Documentation/devicetree/bindings/mux/mmio-mux.txt b/Documentation/devicetree/bindings/mux/mmio-mux.txt
> deleted file mode 100644
> index a9bfb4d8b6ac..000000000000
> --- a/Documentation/devicetree/bindings/mux/mmio-mux.txt
> +++ /dev/null
> @@ -1,60 +0,0 @@
> -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>;
> - };
> - };
> - };
> diff --git a/Documentation/devicetree/bindings/mux/reg-mux.txt b/Documentation/devicetree/bindings/mux/reg-mux.txt
> new file mode 100644
> index 000000000000..320eed948caa
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mux/reg-mux.txt
> @@ -0,0 +1,128 @@
> +Generic register bitfield-based multiplexer controller bindings
> +
> +Define register bitfields to be used to control multiplexers. The parent
> +device tree node must be a device node to provide register r/w access.
> +
> +Required properties:
> +- compatible : should be one of
> + "reg-mux" : if parent device of mux producer is not syscon device
> + "mmio-mux" : if parent device of mux producer is syscon device
> +- #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.
> +
> +Example 1:
> +The parent device of mux producer is not a syscon device.
> +
> +&i2c0 {
> + fpga@66 { // fpga connected to i2c
> + compatible = "fsl,lx2160aqds-fpga", "fsl,fpga-qixis-i2c",
> + "simple-mfd";
> + reg = <0x66>;
> +
> + mux: mux-controller { // Mux Producer
"Mux Producer" is not a concept that exists in any documentation besides
your examples. I do not think the "Mux Producer" / "Mux consumer" comments
adds any value, and think they can just be removed. I felt this from the
start, but it seemed like such a small issue that I tried to ignore it.
But, now you are adding it to the syscon example too, and before I know
it, it will be copied further. And, since there is the issue below in the
example, you need another iteration anyway, so I don't feel toooo bad for
nit-picking this late...
> + compatible = "reg-mux";
> + #mux-control-cells = <1>;
> + mux-reg-masks = <0x54 0xf8>, /* 0: reg 0x54, bits 7:3 */
> + <0x54 0x07>; /* 1: reg 0x54, bits 2:0 */
> + };
> + };
> +};
> +
> +mdio-mux-1 { // Mux consumer
> + compatible = "mdio-mux-multiplexer";
> + mux-controls = <&mux 0>;
> + mdio-parent-bus = <&emdio1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + mdio@0 {
> + reg = <0x0>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + };
> +
> + mdio@8 {
> + reg = <0x8>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + };
> +
> + ..
> + ..
> +};
> +
> +mdio-mux-2 { // Mux consumer
> + compatible = "mdio-mux-multiplexer";
> + mux-controls = <&mux 1>;
> + mdio-parent-bus = <&emdio2>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> +
> + mdio@0 {
> + reg = <0x0>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + };
> +
> + mdio@1 {
> + reg = <0x1>;
> + #address-cells = <1>;
> + #size-cells = <0>;
> + };
> +
> + ..
> + ..
> +};
> +
> +Example 2:
> +The parent device of mux producer is syscon device.
> +
> +syscon {
> + compatible = "syscon";
> +
> + mux: mux-controller { // Mux Producer
> + 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 { // Mux consumer
> + compatible = "video-mux";
> + mux-controls = <&mux 0>;
> +
> + ports {
Not entirely your fault, I know, but this node needs:
#address-cells = <1>;
#size-cells = <0>;
Cheers,
Peter
> + /* inputs 0..3 */
> + port@0 {
> + reg = <0>;
> + };
> + port@1 {
> + reg = <1>;
> + };
> + port@2 {
> + reg = <2>;
> + };
> + port@3 {
> + reg = <3>;
> + };
> +
> + /* output */
> + port@4 {
> + reg = <4>;
> + };
> + };
> +};
> +
>
