[PATCH v2 4/5] mx6cuboxi: fixup dtb ethernet phy nodes before booting an OS

[Josua Mayer]

Hold off on this one, I found a mistake in the switch case below.
While fully functional, it does enable both phy nodes for addresses 0 
and 4 unconditionally.
Cubox requires both, as do potentially any derivate devices - but the 
HummingBoards do not.

Am 19.05.22 um 12:31 schrieb Josua Mayer:
> SoM revision 1.9 has replaced the ar8035 phy address 0 with an adin1300
> at address 1. Because early SoMs had a hardware flaw, the ar8035 can
> also appear at address 4 - making it a total of 3 phy nodes in the DTB.
> 
> To avoid confusing Linux with probe errors, fixup the dtb to only enable
> the phy node that is detected at runtime.
> 
> Signed-off-by: Josua Mayer <josua at solid-run.com>
> ---
>   board/solidrun/mx6cuboxi/mx6cuboxi.c | 78 ++++++++++++++++++++++++++++
>   configs/mx6cuboxi_defconfig          |  1 +
>   2 files changed, 79 insertions(+)
> 
> diff --git a/board/solidrun/mx6cuboxi/mx6cuboxi.c b/board/solidrun/mx6cuboxi/mx6cuboxi.c
> index 6207bf8253..42aa5cb63c 100644
> --- a/board/solidrun/mx6cuboxi/mx6cuboxi.c
> +++ b/board/solidrun/mx6cuboxi/mx6cuboxi.c
> @@ -1,5 +1,7 @@
>   // SPDX-License-Identifier: GPL-2.0+
>   /*
> + * Copyright (C) 2022 Josua Mayer <josua at solid-run.com>
> + *
>    * Copyright (C) 2015 Freescale Semiconductor, Inc.
>    *
>    * Author: Fabio Estevam <fabio.estevam at freescale.com>
> @@ -39,6 +41,8 @@
>   #include <spl.h>
>   #include <usb.h>
>   #include <usb/ehci-ci.h>
> +#include <netdev.h>
> +#include <phy.h>
>   
>   DECLARE_GLOBAL_DATA_PTR;
>   
> @@ -407,6 +411,80 @@ out:
>   	return 0;
>   }
>   
> +static int find_ethernet_phy(void)
> +{
> +	struct mii_dev *bus = NULL;
> +	struct phy_device *phydev = NULL;
> +	int phy_addr = -ENOENT;
> +
> +#ifdef CONFIG_FEC_MXC
> +	bus = fec_get_miibus(ENET_BASE_ADDR, -1);
> +	if (!bus)
> +		return -ENOENT;
> +
> +	// scan address 0, 1, 4
> +	phydev = phy_find_by_mask(bus, 0b00010011);
> +	if (!phydev) {
> +		free(bus);
> +		return -ENOENT;
> +	}
> +	pr_debug("%s: detected ethernet phy at address %d\n", __func__, phydev->addr);
> +	phy_addr = phydev->addr;
> +
> +	free(phydev);
> +#endif
> +
> +	return phy_addr;
> +}
> +
> +#if defined(CONFIG_OF_LIBFDT) && defined(CONFIG_OF_BOARD_SETUP)
> +/*
> + * Configure the correct ethernet PHYs nodes in device-tree:
> + * - AR8035 at addresses 0 or 4: Cubox
> + * - AR8035 at address 0: HummingBoard, HummingBoard 2
> + * - ADIN1300 at address 1: since SoM rev 1.9
> + */
> +int ft_board_setup(void *fdt, struct bd_info *bd)
> +{
> +	int node_phy0, node_phy1, node_phy4;
> +	int ret, phy;
> +	bool enable_phy0 = false, enable_phy1 = false, enable_phy4 = false;
> +
> +	// detect phy
> +	phy = find_ethernet_phy();
> +	if (phy == 0 || phy == 4) {
> +		enable_phy0 = true;
> +		switch (board_type()) {
> +		case CUBOXI:
> +		case UNKNOWN:
> +		default:
> +			enable_phy4 = true;
> +		}
> +	} else if (phy == 1) {
> +		enable_phy1 = true;
> +	} else {
> +		pr_err("%s: couldn't detect ethernet phy, not patching dtb!\n", __func__);
> +		return 0;
> +	}
> +
> +	// update all phy nodes status
> +	node_phy0 = fdt_path_offset(fdt, "/soc/bus at 2100000/ethernet at 2188000/mdio/ethernet-phy at 0");
> +	ret = fdt_setprop_string(fdt, node_phy0, "status", enable_phy0 ? "okay" : "disabled");
> +	if (ret < 0 && enable_phy0)
> +		pr_err("%s: failed to enable ethernet phy at address 0 in dtb!\n", __func__);
> +	node_phy1 = fdt_path_offset(fdt, "/soc/bus at 2100000/ethernet at 2188000/mdio/ethernet-phy at 1");
> +	ret = fdt_setprop_string(fdt, node_phy1, "status", enable_phy1 ? "okay" : "disabled");
> +	if (ret < 0 && enable_phy1)
> +		pr_err("%s: failed to enable ethernet phy at address 1 in dtb!\n", __func__);
> +	node_phy4 = fdt_path_offset(fdt, "/soc/bus at 2100000/ethernet at 2188000/mdio/ethernet-phy at 4");
> +	ret = fdt_setprop_string(fdt, node_phy4, "status", enable_phy4 ? "okay" : "disabled");
> +	if (ret < 0 && enable_phy4)
> +		pr_err("%s: failed to enable ethernet phy at address 4 in dtb!\n", __func__);
> +
> +	return 0;
> +}
> +#endif
> +
>   /* Override the default implementation, DT model is not accurate */
>   int show_board_info(void)
>   {
> diff --git a/configs/mx6cuboxi_defconfig b/configs/mx6cuboxi_defconfig
> index 1e2e332af9..d3ac8eeeba 100644
> --- a/configs/mx6cuboxi_defconfig
> +++ b/configs/mx6cuboxi_defconfig
> @@ -22,6 +22,7 @@ CONFIG_CMD_HDMIDETECT=y
>   CONFIG_AHCI=y
>   CONFIG_DISTRO_DEFAULTS=y
>   CONFIG_FIT=y
> +CONFIG_OF_BOARD_SETUP=y
>   CONFIG_BOOTCOMMAND="run findfdt; run finduuid; run distro_bootcmd"
>   CONFIG_USE_PREBOOT=y
>   CONFIG_PREBOOT="if hdmidet; then usb start; setenv stdin  serial,usbkbd; setenv stdout serial,vidconsole; setenv stderr serial,vidconsole; else setenv stdin  serial; setenv stdout serial; setenv stderr serial; fi;"