[PATCH u-boot-mvebu] arm: mvebu: turris_omnia: Fix ethernet PHY reset gpio FDT fixup

["Marek Behún" <kabel@kernel.org>]

For board revisions where the WAN ethernet PHY reset GPIO is controllable
via MCU we currently insert a phy-reset-gpios property into the ethernet
controller node. The mvneta driver parses this property and uses the
GPIO to reset the PHY.

But this phy-reset-gpios property is not a valid DT binding in upstream
kernel. Instead, a reset-gpios property should be inserted into the
ethernet PHY node. This correct DT binding is supported by the DM ETH PHY
U-Boot driver.

Insert the reset-gpios property into the WAN PHY node instead the
phy-reset-gpios property in WAN ETH node so that Linux will correctly use
the reset GPIO.

Enable the CONFIG_DM_ETH_PHY config option so that U-Boot will also use
the correct DT property.

Note: currently there are 4 ethernet controller drivers parsing the
wrong DT property: dwc_eth_qos, fex_mxc, mvneta and mvpp2. We should
convert all relevant device-trees to use reset-gpios so that we can get
rid of these drivers parsing this property.

Fixes: 1da53ae26afc ("arm: mvebu: turris_omnia: Add support for design with SW reset signals")
Signed-off-by: Marek Behún <kabel@kernel.org>
---
 board/CZ.NIC/turris_omnia/turris_omnia.c | 44 ++++++++++++++----------
 configs/turris_omnia_defconfig           |  1 +
 2 files changed, 26 insertions(+), 19 deletions(-)

diff --git a/board/CZ.NIC/turris_omnia/turris_omnia.c b/board/CZ.NIC/turris_omnia/turris_omnia.c
index 3b7a71bdad..448655c294 100644
--- a/board/CZ.NIC/turris_omnia/turris_omnia.c
+++ b/board/CZ.NIC/turris_omnia/turris_omnia.c
@@ -978,11 +978,21 @@ static int fixup_mcu_gpio_in_pcie_nodes(void *blob)
 	return 0;
 }
 
-static int fixup_mcu_gpio_in_eth_wan_node(void *blob)
+static int get_phy_wan_node_offset(const void *blob)
+{
+	u32 phy_wan_phandle;
+
+	phy_wan_phandle = fdt_getprop_u32_default(blob, "ethernet2", "phy-handle", 0);
+	if (!phy_wan_phandle)
+		return -FDT_ERR_NOTFOUND;
+
+	return fdt_node_offset_by_phandle(blob, phy_wan_phandle);
+}
+
+static int fixup_mcu_gpio_in_phy_wan_node(void *blob)
 {
 	unsigned int mcu_phandle;
-	int eth_wan_node;
-	int ret;
+	int phy_wan_node, ret;
 
 	ret = fdt_increase_size(blob, 64);
 	if (ret < 0) {
@@ -990,21 +1000,17 @@ static int fixup_mcu_gpio_in_eth_wan_node(void *blob)
 		return ret;
 	}
 
-	eth_wan_node = fdt_path_offset(blob, "ethernet2");
-	if (eth_wan_node < 0)
-		return eth_wan_node;
+	phy_wan_node = get_phy_wan_node_offset(blob);
+	if (phy_wan_node < 0)
+		return phy_wan_node;
 
 	mcu_phandle = fdt_create_phandle_by_compatible(blob, "cznic,turris-omnia-mcu");
 	if (!mcu_phandle)
 		return -FDT_ERR_NOPHANDLES;
 
-	/* insert: phy-reset-gpios = <&mcu 2 gpio GPIO_ACTIVE_LOW>; */
-	ret = insert_mcu_gpio_prop(blob, eth_wan_node, "phy-reset-gpios",
-				   mcu_phandle, 2, ilog2(EXT_CTL_nRES_PHY), GPIO_ACTIVE_LOW);
-	if (ret < 0)
-		return ret;
-
-	return 0;
+	/* insert: reset-gpios = <&mcu 2 gpio GPIO_ACTIVE_LOW>; */
+	return insert_mcu_gpio_prop(blob, phy_wan_node, "reset-gpios",
+				    mcu_phandle, 2, ilog2(EXT_CTL_nRES_PHY), GPIO_ACTIVE_LOW);
 }
 
 static void fixup_atsha_node(void *blob)
@@ -1033,7 +1039,7 @@ int board_fix_fdt(void *blob)
 {
 	if (omnia_mcu_has_feature(FEAT_PERIPH_MCU)) {
 		fixup_mcu_gpio_in_pcie_nodes(blob);
-		fixup_mcu_gpio_in_eth_wan_node(blob);
+		fixup_mcu_gpio_in_phy_wan_node(blob);
 	}
 
 	fixup_msata_port_nodes(blob);
@@ -1218,14 +1224,14 @@ int ft_board_setup(void *blob, struct bd_info *bd)
 	int node;
 
 	/*
-	 * U-Boot's FDT blob contains phy-reset-gpios in ethernet2
-	 * node when MCU controls all peripherals resets.
+	 * U-Boot's FDT blob contains reset-gpios in ethernet2 PHY node when MCU
+	 * controls all peripherals resets.
 	 * Fixup MCU GPIO nodes in PCIe and eth wan nodes in this case.
 	 */
-	node = fdt_path_offset(gd->fdt_blob, "ethernet2");
-	if (node >= 0 && fdt_getprop(gd->fdt_blob, node, "phy-reset-gpios", NULL)) {
+	node = get_phy_wan_node_offset(gd->fdt_blob);
+	if (node >= 0 && fdt_getprop(gd->fdt_blob, node, "reset-gpios", NULL)) {
 		fixup_mcu_gpio_in_pcie_nodes(blob);
-		fixup_mcu_gpio_in_eth_wan_node(blob);
+		fixup_mcu_gpio_in_phy_wan_node(blob);
 	}
 
 	fixup_spi_nor_partitions(blob);
diff --git a/configs/turris_omnia_defconfig b/configs/turris_omnia_defconfig
index 11256be8dd..d7005e7334 100644
--- a/configs/turris_omnia_defconfig
+++ b/configs/turris_omnia_defconfig
@@ -100,6 +100,7 @@ CONFIG_SPI_FLASH_MTD=y
 CONFIG_PHY_MARVELL=y
 CONFIG_PHY_FIXED=y
 CONFIG_DM_DSA=y
+CONFIG_DM_ETH_PHY=y
 CONFIG_PHY_GIGE=y
 CONFIG_MV88E6XXX=y
 CONFIG_MVNETA=y
-- 
2.43.2