Re: [PATCH v4 3/4] arm: kirkwood: Pogoplug-V4 : Add board implementation files

[Pali Rohár]

On Thursday 20 January 2022 17:50:54 Tony Dinh wrote:
> diff --git a/board/cloudengines/pogo_v4/pogo_v4.c 
> b/board/cloudengines/pogo_v4/pogo_v4.c
> new file mode 100644
> index 0000000000..c85de0b22e
> --- /dev/null
> +++ b/board/cloudengines/pogo_v4/pogo_v4.c
> +int fdt_get_phy_addr(const char *path)
> +{
> +     const void *fdt = gd->fdt_blob;
> +     const u32 *reg;
> +     const u32 *val;
> +     int node, phandle, addr;
> +
> +     /* Find the node by its full path */
> +     node = fdt_path_offset(fdt, path);
> +     if (node >= 0) {
> +             /* Look up phy-handle */
> +             val = fdt_getprop(fdt, node, "phy-handle", NULL);
> +             if (!val) {
> +                     /* Look up phy (deprecated property for phy handle) */
> +                     val = fdt_getprop(fdt, node, "phy", NULL);
> +             }
> +             if (val) {
> +                     phandle = fdt32_to_cpu(*val);
> +                     if (!phandle)
> +                             return -FDT_ERR_NOTFOUND;
> +
> +                     /* Follow it to its node */
> +                     node = fdt_node_offset_by_phandle(fdt, phandle);
> +                     if (node) {
> +                             /* Look up reg */
> +                             reg = fdt_getprop(fdt, node, "reg", NULL);
> +                             if (reg) {
> +                                     addr = fdt32_to_cpu(*reg);
> +                                     return addr;
> +                             }
> +                     }
> +             }
> +     }
> +     return -FDT_ERR_NOTFOUND;
> +}
> +
> +#if defined(CONFIG_RESET_PHY_R)
> +/* Configure and initialize PHY */
> +void reset_phy(void)
> +{
> +     u16 reg;
> +     int phyaddr;
> +     char *name = "ethernet-controller@72000";
> +     char *eth0_path = "/ocp@f1000000/ethernet-controller@72000";

Hello! I would suggest to avoid hardcoding DT node names and DT node
paths into source code.

How to avoid it?

In DTS file define alias "ethernet0" as alias to eth0 node:

        aliases {
                ethernet0 = &eth0;
        };

(just before memory {} node)

&eth0 label is already defined in arch/arm/dts/kirkwood.dtsi.

Function fdt_path_offset() understands either full path or alias. So you
can call fdt_get_phy_addr("ethernet0").

And to get node name you can use function fdt_get_name() which takes
node offset - return value of fdt_path_offset().

And maybe... to avoid calling fdt_path_offset() two times, you may
adjust fdt_get_phy_addr() to directly take node offset (not path/alias).

So something like this:

    node = fdt_path_offset(gd->fdt_blob, "ethernet0");
    ... error checking ...
    name = fdt_get_name(gd->fdt_blob, node, NULL);
    ... error checking ...
    miiphy_set_current_dev(name);
    ... error checking ...
    fdt_get_phy_addr(node);
    ... error checking ...


> +     if (miiphy_set_current_dev(name))
> +             return;
> +
> +     phyaddr = fdt_get_phy_addr(eth0_path);
> +     if (phyaddr < 0)
> +             return;
> +
> +     /*
> +      * Enable RGMII delay on Tx and Rx for CPU port
> +      * Ref: sec 4.7.2 of chip datasheet
> +      */
> +     miiphy_write(name, phyaddr, MV88E1116_PGADR_REG, 2);
> +     miiphy_read(name, phyaddr, MV88E1116_MAC_CTRL_REG, &reg);
> +     reg |= (MV88E1116_RGMII_RXTM_CTRL | MV88E1116_RGMII_TXTM_CTRL);
> +     miiphy_write(name, phyaddr, MV88E1116_MAC_CTRL_REG, reg);
> +     miiphy_write(name, phyaddr, MV88E1116_PGADR_REG, 0);
> +
> +     /* reset the phy */
> +     miiphy_reset(name, phyaddr);
> +
> +     printf("88E1116 Initialized on %s\n", name);
> +}