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

[Josua Mayer <josua@solid-run.com>]

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@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@solid-run.com>
+ *
  * Copyright (C) 2015 Freescale Semiconductor, Inc.
  *
  * Author: Fabio Estevam <fabio.estevam@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@2100000/ethernet@2188000/mdio/ethernet-phy@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@2100000/ethernet@2188000/mdio/ethernet-phy@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@2100000/ethernet@2188000/mdio/ethernet-phy@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;"
-- 
2.34.1