lkml.org 
[lkml]   [2017]   [Apr]   [13]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [RFC 1/2] dt-bindings: add mmio-based syscon mux controller DT bindings
From
Date


On 04/13/2017 08:48 AM, Philipp Zabel wrote:
> This adds device tree binding documentation for mmio-based syscon
> multiplexers controlled by a single bitfield in a syscon register
> range.

Nice! (you beat me to it, I was about to embark on this myself :)

Looks good to me, just some minor comments below.

>
> Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
> ---
> Documentation/devicetree/bindings/mux/mmio-mux.txt | 56 ++++++++++++++++++++++
> 1 file changed, 56 insertions(+)
> create mode 100644 Documentation/devicetree/bindings/mux/mmio-mux.txt
>
> diff --git a/Documentation/devicetree/bindings/mux/mmio-mux.txt b/Documentation/devicetree/bindings/mux/mmio-mux.txt
> new file mode 100644
> index 0000000000000..11d96f5d98583
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/mux/mmio-mux.txt
> @@ -0,0 +1,56 @@
> +MMIO bitfield-based multiplexer controller bindings
> +
> +Define a syscon bitfield to be used to control a multiplexer. The parent

I think "Define a register bitfield to be used ..." is more clear.

> +device tree node must be a syscon node to provide register access.
> +
> +Required properties:
> +- compatible : "gpio-mux"

Er, "mmio-mux"

> +- reg : register base of the register containing the control bitfield
> +- bit-mask : bitmask of the control bitfield in the control register
> +- bit-shift : bit offset of the control bitfield in the control register
> +- #mux-control-cells : <0>
> +* Standard mux-controller bindings as decribed in mux-controller.txt
> +
> +Optional properties:
> +- idle-state : if present, the state the mux will have when idle. The
> + special state MUX_IDLE_AS_IS is the default.
> +
> +The multiplexer state is defined as the value of the bitfield described
> +by the reg, bit-mask, and bit-shift properties, accessed through the parent
> +syscon.
> +
> +Example:
> +
> + syscon {
> + compatible = "syscon";
> +
> + mux: mux-controller@3 {
> + compatible = "mmio-mux";
> + reg = <0x3>;
> + bit-mask = <0x1>;
> + bit-shift = <5>;
> + #mux-control-cells = <0>;
> + };
> + };
> +
> + video-mux {

I like this as an example consumer of a mmio-mux, but just
the same some might argue this doesn't really fit here.

Steve

> + compatible = "video-mux";
> + mux-controls = <&mux>;
> +
> + ports {
> + /* input 0 */
> + port@0 {
> + reg = <0>;
> + };
> +
> + /* input 1 */
> + port@1 {
> + reg = <1>;
> + };
> +
> + /* output */
> + port@2 {
> + reg = <2>;
> + };
> + };
> + };

\
 
 \ /
  Last update: 2017-04-14 03:04    [W:1.647 / U:0.052 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site