On 7/8/2019 10:40 AM, Bin Meng wrote:
On Tue, Jun 18, 2019 at 10:58 PM Alexandru Marginean alexandru.marginean@nxp.com wrote:
Adds a short bindings document describing the expected structure of a MDIO MUX dts node. This is based on Linux binding and the example is in fact copied from there.
Signed-off-by: Alex Marginean alexm.osslist@gmail.com
Changes in v2: - no change Changes in v3: - no change, just fighting with the email server
doc/device-tree-bindings/net/mdio-mux.txt | 61 +++++++++++++++++++++++ 1 file changed, 61 insertions(+) create mode 100644 doc/device-tree-bindings/net/mdio-mux.txt
diff --git a/doc/device-tree-bindings/net/mdio-mux.txt b/doc/device-tree-bindings/net/mdio-mux.txt new file mode 100644 index 0000000000..fdf817fd93 --- /dev/null +++ b/doc/device-tree-bindings/net/mdio-mux.txt @@ -0,0 +1,61 @@ +The expected structure of an MDIO MUX device tree node is described here. This +is heavily based on current Linux specification. +The MDIO buses downstream of the MUX should be described in the device tree as +child nodes as indicated below.
+Required properties: +mdio-parent-bus = a phandle to the MDIO bus used to perform actual I/O. This is
typically a real MDIO device, unless there are cascaded MUXes.In Linux, "mdio-parent-bus" is optional, but in U-Boot this is required?
That was my plan, making it optional requires some extra code that I didn't put in. I could put that code in but it would be unused for now. I can do it, or the change can be done whenever someone adds a MUX which is driven over parent MDIO.
+#address-cells = <1>, each MDIO group is identified by one 32b value. +#size-cells = <0>
+Other properties: +The properties described here are sufficient for MDIO MUX DM class code, but +MUX drivers may define additional properties, either required or optional.
+Required properties in child nodes: +reg = value to be configured on the MUX to select the respective downstream
MDIO.+Child nodes should normally contain PHY nodes, referenced by phandle from +ethernet nodes of the eth interfaces using these PHYs.
+Example structure, extracted from Linux bindings document:
/* The parent MDIO bus. */smi1: mdio@1180000001900 {compatible = "cavium,octeon-3860-mdio";#address-cells = <1>;#size-cells = <0>;reg = <0x11800 0x00001900 0x0 0x40>;};/*An NXP sn74cbtlv3253 dual 1-of-4 switch controlled by apair of GPIO lines. Child busses 2 and 3 populated with 4PHYs each.*/It looks the example is not complete, which makes it hard for people to understand (ie: only bus 2 is listed below) without reading the Linux bindings doc.
I did chop it down to the piece I though it's relevant, I can pull in the full example. Or I can replace it with the definition of the device I'm working on, that way the example is practical. 'mdio-mux-gpio' is not something I was planning to add to u-boot now.
Thank you! Alex
mdio-mux {compatible = "mdio-mux-gpio";gpios = <&gpio1 3 0>, <&gpio1 4 0>;mdio-parent-bus = <&smi1>;#address-cells = <1>;#size-cells = <0>;mdio@2 {reg = <2>;#address-cells = <1>;#size-cells = <0>;phy11: ethernet-phy@1 {reg = <1>;marvell,reg-init = <3 0x10 0 0x5777>,<3 0x11 0 0x00aa>,<3 0x12 0 0x4105>,<3 0x13 0 0x0a60>;interrupt-parent = <&gpio>;interrupts = <10 8>; /* Pin 10, active low */};};};Regards, Bin _______________________________________________ U-Boot mailing list U-Boot@lists.denx.de https://lists.denx.de/listinfo/u-boot