[PATCH net-next v7 0/3] Add support for Nuvoton MA35D1 GMAC

[PATCH net-next v7 0/3] Add support for Nuvoton MA35D1 GMAC

[Joey Lu]

This patch series is submitted to add GMAC support for Nuvoton MA35D1
SoC platform. This work involves implementing a GMAC driver glue layer
based on Synopsys DWMAC driver framework to leverage MA35D1's dual GMAC
interface capabilities.

Overview:
  1. Added a GMAC driver glue layer for MA35D1 SoC, providing support for
  the platform's two GMAC interfaces.
  2. Added device tree settings, with specific configurations for our
  development boards:
    a. SOM board: Configured for two RGMII interfaces.
    b. IoT board: Configured with one RGMII and one RMII interface.
  3. Added dt-bindings for the GMAC interfaces.

v7:
  - Update dwmac-nuvoton driver
    - Update probe function to use stmmac_pltfr_probe instead.

v6:
  - Update dwmac-nuvoton driver
    - Use NVT as the previx for all functions, structs, and defines.
    - Remove unnecessary comments.

v5:
  - Update yaml
    - Remove the properties already defined in snps dwmac.
  - Update dwmac-nuvoton driver
    - Add a comment to explain the override of PMT flag.

v4:
  - Update yaml
    - Remove unnecessary property 'select'.
    - Remove unnecessary compatible entries and fix items.
    - Specify number of entries for 'reg'.
    - Remove already defined property 'phy-handle'.
    - Update example.
    - Modify the property internal path delay to match the driver.
  - Update dtsi
    - Move 'status' to be the last property.
  - Update dwmac-nuvoton driver
    - Use remove instead of remove_new.
    - Use dev_err_probe instead.

v3:
  - Update yaml
    - Fix for dt_binding_check warnings & errors.
    - Add compatible in snps dwmac.
  - Update dtsi
    - Update dtsi to follow examples in yaml.
  - Update dwmac-nuvoton driver
    - Fix for auto build test warnings.
    - Invalid path delay arguments will be returned.

v2:
  - Update yaml
    - Rename file to align with the compatible property.
    - Add an argument to syscon to replace mac-id,
      with corresponding descriptions.
    - Use tx-internal-delay-ps and rx-internal-delay-ps properties for
      configurable path delay with corresponding descriptions,
      allowing selection between GMAC internal and PHY.
    - Add all supported phy-mode options.
    - Remove unused properties.
  - Update dtsi
    - Modify syscon configuration to include an argument for
      GMAC interface selection.
  - Update dwmac-nuvoton driver
    - Remove redundant device information print statements.
    - Remove non-global parameters.
    - Retrieve GMAC interface selection from the syscon argument.
    - Parse Tx and Rx path delays by correct properties.
    - Update configurations to support Wake-on-LAN.

Joey Lu (3):
  dt-bindings: net: nuvoton: Add schema for Nuvoton MA35 family GMAC
  arm64: dts: nuvoton: Add Ethernet nodes
  net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

 .../bindings/net/nuvoton,ma35d1-dwmac.yaml    | 126 ++++++++++++
 .../devicetree/bindings/net/snps,dwmac.yaml   |   1 +
 .../boot/dts/nuvoton/ma35d1-iot-512m.dts      |  12 ++
 .../boot/dts/nuvoton/ma35d1-som-256m.dts      |  10 +
 arch/arm64/boot/dts/nuvoton/ma35d1.dtsi       |  54 ++++++
 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
 drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
 .../ethernet/stmicro/stmmac/dwmac-nuvoton.c   | 179 ++++++++++++++++++
 8 files changed, 394 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/nuvoton,ma35d1-dwmac.yaml
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c

-- 
2.34.1

[PATCH net-next v7 1/3] dt-bindings: net: nuvoton: Add schema for Nuvoton MA35 family GMAC

[Joey Lu]

Create initial schema for Nuvoton MA35 family Gigabit MAC.

Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Joey Lu <a0987203069@gmail.com>
---
 .../bindings/net/nuvoton,ma35d1-dwmac.yaml    | 126 ++++++++++++++++++
 .../devicetree/bindings/net/snps,dwmac.yaml   |   1 +
 2 files changed, 127 insertions(+)
 create mode 100644 Documentation/devicetree/bindings/net/nuvoton,ma35d1-dwmac.yaml

diff --git a/Documentation/devicetree/bindings/net/nuvoton,ma35d1-dwmac.yaml b/Documentation/devicetree/bindings/net/nuvoton,ma35d1-dwmac.yaml
new file mode 100644
index 000000000000..c3f2ad423cc0
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/nuvoton,ma35d1-dwmac.yaml
@@ -0,0 +1,126 @@
+# SPDX-License-Identifier: (GPL-2.0-only OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/net/nuvoton,ma35d1-dwmac.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Nuvoton DWMAC glue layer controller
+
+maintainers:
+  - Joey Lu <yclu4@nuvoton.com>
+
+description:
+  Nuvoton 10/100/1000Mbps Gigabit Ethernet MAC Controller is based on
+  Synopsys DesignWare MAC (version 3.73a).
+
+allOf:
+  - $ref: snps,dwmac.yaml#
+
+properties:
+  compatible:
+    items:
+      - enum:
+          - nuvoton,ma35d1-dwmac
+
+  reg:
+    maxItems: 1
+    description:
+      Register range should be one of the GMAC interface.
+
+  interrupts:
+    maxItems: 1
+
+  clocks:
+    items:
+      - description: MAC clock
+      - description: PTP clock
+
+  clock-names:
+    items:
+      - const: stmmaceth
+      - const: ptp_ref
+
+  nuvoton,sys:
+    $ref: /schemas/types.yaml#/definitions/phandle-array
+    items:
+      - items:
+          - description: phandle to access syscon registers.
+          - description: GMAC interface ID.
+            enum:
+              - 0
+              - 1
+    description:
+      A phandle to the syscon with one argument that configures system registers
+      for MA35D1's two GMACs. The argument specifies the GMAC interface ID.
+
+  resets:
+    maxItems: 1
+
+  reset-names:
+    items:
+      - const: stmmaceth
+
+  phy-mode:
+    enum:
+      - rmii
+      - rgmii
+      - rgmii-id
+      - rgmii-txid
+      - rgmii-rxid
+
+  tx-internal-delay-ps:
+    default: 0
+    minimum: 0
+    maximum: 2000
+    description:
+      RGMII TX path delay used only when PHY operates in RGMII mode with
+      internal delay (phy-mode is 'rgmii-id' or 'rgmii-txid') in pico-seconds.
+      Allowed values are from 0 to 2000.
+
+  rx-internal-delay-ps:
+    default: 0
+    minimum: 0
+    maximum: 2000
+    description:
+      RGMII RX path delay used only when PHY operates in RGMII mode with
+      internal delay (phy-mode is 'rgmii-id' or 'rgmii-rxid') in pico-seconds.
+      Allowed values are from 0 to 2000.
+
+required:
+  - clocks
+  - clock-names
+  - nuvoton,sys
+  - resets
+  - reset-names
+
+unevaluatedProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/nuvoton,ma35d1-clk.h>
+    #include <dt-bindings/reset/nuvoton,ma35d1-reset.h>
+    ethernet@40120000 {
+        compatible = "nuvoton,ma35d1-dwmac";
+        reg = <0x40120000 0x10000>;
+        interrupts = <GIC_SPI 23 IRQ_TYPE_LEVEL_HIGH>;
+        interrupt-names = "macirq";
+        clocks = <&clk EMAC0_GATE>, <&clk EPLL_DIV8>;
+        clock-names = "stmmaceth", "ptp_ref";
+
+        nuvoton,sys = <&sys 0>;
+        resets = <&sys MA35D1_RESET_GMAC0>;
+        reset-names = "stmmaceth";
+
+        phy-mode = "rgmii-id";
+        phy-handle = <&eth_phy0>;
+        mdio {
+            compatible = "snps,dwmac-mdio";
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            ethernet-phy@0 {
+                reg = <0>;
+            };
+        };
+    };
diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
index 91e75eb3f329..c43dcae74495 100644
--- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
@@ -67,6 +67,7 @@ properties:
         - ingenic,x2000-mac
         - loongson,ls2k-dwmac
         - loongson,ls7a-dwmac
+        - nuvoton,ma35d1-dwmac
         - nxp,s32g2-dwmac
         - qcom,qcs404-ethqos
         - qcom,sa8775p-ethqos
-- 
2.34.1

[PATCH net-next v7 2/3] arm64: dts: nuvoton: Add Ethernet nodes

[Joey Lu]

Add GMAC nodes for our MA35D1 development boards:
two RGMII interfaces for SOM board, and one RGMII and one RMII interface for IoT board.

Signed-off-by: Joey Lu <a0987203069@gmail.com>
---
 .../boot/dts/nuvoton/ma35d1-iot-512m.dts      | 12 +++++
 .../boot/dts/nuvoton/ma35d1-som-256m.dts      | 10 ++++
 arch/arm64/boot/dts/nuvoton/ma35d1.dtsi       | 54 +++++++++++++++++++
 3 files changed, 76 insertions(+)

diff --git a/arch/arm64/boot/dts/nuvoton/ma35d1-iot-512m.dts b/arch/arm64/boot/dts/nuvoton/ma35d1-iot-512m.dts
index 9482bec1aa57..5cc712ae92d8 100644
--- a/arch/arm64/boot/dts/nuvoton/ma35d1-iot-512m.dts
+++ b/arch/arm64/boot/dts/nuvoton/ma35d1-iot-512m.dts
@@ -18,6 +18,8 @@ aliases {
 		serial12 = &uart12;
 		serial13 = &uart13;
 		serial14 = &uart14;
+		ethernet0 = &gmac0;
+		ethernet1 = &gmac1;
 	};
 
 	chosen {
@@ -126,3 +128,13 @@ &uart14 {
 	pinctrl-0 = <&pinctrl_uart14>;
 	status = "okay";
 };
+
+&gmac0 {
+	phy-mode = "rgmii-id";
+	status = "okay";
+};
+
+&gmac1 {
+	phy-mode = "rmii";
+	status = "okay";
+};
diff --git a/arch/arm64/boot/dts/nuvoton/ma35d1-som-256m.dts b/arch/arm64/boot/dts/nuvoton/ma35d1-som-256m.dts
index f6f20a17e501..1d9ac350a1f1 100644
--- a/arch/arm64/boot/dts/nuvoton/ma35d1-som-256m.dts
+++ b/arch/arm64/boot/dts/nuvoton/ma35d1-som-256m.dts
@@ -18,6 +18,8 @@ aliases {
 		serial12 = &uart12;
 		serial14 = &uart14;
 		serial16 = &uart16;
+		ethernet0 = &gmac0;
+		ethernet1 = &gmac1;
 	};
 
 	chosen {
@@ -129,3 +131,11 @@ &uart16 {
 	pinctrl-0 = <&pinctrl_uart16>;
 	status = "okay";
 };
+
+&gmac0 {
+	status = "okay";
+};
+
+&gmac1 {
+	status = "okay";
+};
diff --git a/arch/arm64/boot/dts/nuvoton/ma35d1.dtsi b/arch/arm64/boot/dts/nuvoton/ma35d1.dtsi
index e51b98f5bdce..89712e262ee6 100644
--- a/arch/arm64/boot/dts/nuvoton/ma35d1.dtsi
+++ b/arch/arm64/boot/dts/nuvoton/ma35d1.dtsi
@@ -379,5 +379,59 @@ uart16: serial@40880000 {
 			clocks = <&clk UART16_GATE>;
 			status = "disabled";
 		};
+
+		gmac0: ethernet@40120000 {
+			compatible = "nuvoton,ma35d1-dwmac";
+			reg = <0x0 0x40120000 0x0 0x10000>;
+			interrupts = <GIC_SPI 23 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "macirq";
+			clocks = <&clk EMAC0_GATE>, <&clk EPLL_DIV8>;
+			clock-names = "stmmaceth", "ptp_ref";
+
+			nuvoton,sys = <&sys 0>;
+			resets = <&sys MA35D1_RESET_GMAC0>;
+			reset-names = "stmmaceth";
+
+			phy-mode = "rgmii-id";
+			phy-handle = <&eth_phy0>;
+			status = "disabled";
+
+			mdio0: mdio {
+				compatible = "snps,dwmac-mdio";
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				eth_phy0: ethernet-phy@0 {
+					reg = <0>;
+				};
+			};
+		};
+
+		gmac1: ethernet@40130000 {
+			compatible = "nuvoton,ma35d1-dwmac";
+			reg = <0x0 0x40130000 0x0 0x10000>;
+			interrupts = <GIC_SPI 24 IRQ_TYPE_LEVEL_HIGH>;
+			interrupt-names = "macirq";
+			clocks = <&clk EMAC1_GATE>, <&clk EPLL_DIV8>;
+			clock-names = "stmmaceth", "ptp_ref";
+
+			nuvoton,sys = <&sys 1>;
+			resets = <&sys MA35D1_RESET_GMAC1>;
+			reset-names = "stmmaceth";
+
+			phy-mode = "rgmii-id";
+			phy-handle = <&eth_phy1>;
+			status = "disabled";
+
+			mdio1: mdio {
+				compatible = "snps,dwmac-mdio";
+				#address-cells = <1>;
+				#size-cells = <0>;
+
+				eth_phy1: ethernet-phy@1 {
+					reg = <1>;
+				};
+			};
+		};
 	};
 };
-- 
2.34.1

[PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Joey Lu]

Add support for Gigabit Ethernet on Nuvoton MA35 series using dwmac driver.

Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Joey Lu <a0987203069@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
 drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
 .../ethernet/stmicro/stmmac/dwmac-nuvoton.c   | 179 ++++++++++++++++++
 3 files changed, 191 insertions(+)
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 4cc85a36a1ab..2b424544cf6f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -121,6 +121,17 @@ config DWMAC_MESON
 	  the stmmac device driver. This driver is used for Meson6,
 	  Meson8, Meson8b and GXBB SoCs.
 
+config DWMAC_NUVOTON
+	tristate "Nuvoton MA35 dwmac support"
+	default ARCH_MA35
+	depends on OF && (ARCH_MA35 || COMPILE_TEST)
+	select MFD_SYSCON
+	help
+	  Support for Ethernet controller on Nuvoton MA35 series SoC.
+
+	  This selects the Nuvoton MA35 series SoC glue layer support
+	  for the stmmac device driver.
+
 config DWMAC_QCOM_ETHQOS
 	tristate "Qualcomm ETHQOS support"
 	default ARCH_QCOM
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index b26f0e79c2b3..48e25b85ea06 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -19,6 +19,7 @@ obj-$(CONFIG_DWMAC_IPQ806X)	+= dwmac-ipq806x.o
 obj-$(CONFIG_DWMAC_LPC18XX)	+= dwmac-lpc18xx.o
 obj-$(CONFIG_DWMAC_MEDIATEK)	+= dwmac-mediatek.o
 obj-$(CONFIG_DWMAC_MESON)	+= dwmac-meson.o dwmac-meson8b.o
+obj-$(CONFIG_DWMAC_NUVOTON)	+= dwmac-nuvoton.o
 obj-$(CONFIG_DWMAC_QCOM_ETHQOS)	+= dwmac-qcom-ethqos.o
 obj-$(CONFIG_DWMAC_ROCKCHIP)	+= dwmac-rk.o
 obj-$(CONFIG_DWMAC_RZN1)	+= dwmac-rzn1.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
new file mode 100644
index 000000000000..edf1b88ce1cd
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
@@ -0,0 +1,179 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Nuvoton DWMAC specific glue layer
+ *
+ * Copyright (C) 2024 Nuvoton Technology Corp.
+ *
+ * Author: Joey Lu <yclu4@nuvoton.com>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/stmmac.h>
+
+#include "stmmac.h"
+#include "stmmac_platform.h"
+
+#define NVT_REG_SYS_GMAC0MISCR  0x108
+#define NVT_REG_SYS_GMAC1MISCR  0x10C
+
+#define NVT_MISCR_RMII          BIT(0)
+
+/* 2000ps is mapped to 0x0 ~ 0xF */
+#define NVT_PATH_DELAY_DEC      134
+#define NVT_TX_DELAY_MASK       GENMASK(19, 16)
+#define NVT_RX_DELAY_MASK       GENMASK(23, 20)
+
+struct nvt_priv_data {
+	struct platform_device *pdev;
+	struct regmap *regmap;
+};
+
+static struct nvt_priv_data *
+nvt_gmac_setup(struct platform_device *pdev, struct plat_stmmacenet_data *plat)
+{
+	struct device *dev = &pdev->dev;
+	struct nvt_priv_data *bsp_priv;
+	phy_interface_t phy_mode;
+	u32 tx_delay, rx_delay;
+	u32 macid, arg, reg;
+
+	bsp_priv = devm_kzalloc(dev, sizeof(*bsp_priv), GFP_KERNEL);
+	if (!bsp_priv)
+		return ERR_PTR(-ENOMEM);
+
+	bsp_priv->regmap =
+		syscon_regmap_lookup_by_phandle_args(dev->of_node, "nuvoton,sys", 1, &macid);
+	if (IS_ERR(bsp_priv->regmap)) {
+		dev_err_probe(dev, PTR_ERR(bsp_priv->regmap), "Failed to get sys register\n");
+		return ERR_PTR(-ENODEV);
+	}
+	if (macid > 1) {
+		dev_err_probe(dev, -EINVAL, "Invalid sys arguments\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (of_property_read_u32(dev->of_node, "tx-internal-delay-ps", &arg)) {
+		tx_delay = 0;
+	} else {
+		if (arg <= 2000) {
+			tx_delay = (arg == 2000) ? 0xF : (arg / NVT_PATH_DELAY_DEC);
+			dev_dbg(dev, "Set Tx path delay to 0x%x\n", tx_delay);
+		} else {
+			dev_err(dev, "Invalid Tx path delay argument.\n");
+			return ERR_PTR(-EINVAL);
+		}
+	}
+	if (of_property_read_u32(dev->of_node, "rx-internal-delay-ps", &arg)) {
+		rx_delay = 0;
+	} else {
+		if (arg <= 2000) {
+			rx_delay = (arg == 2000) ? 0xF : (arg / NVT_PATH_DELAY_DEC);
+			dev_dbg(dev, "Set Rx path delay to 0x%x\n", rx_delay);
+		} else {
+			dev_err(dev, "Invalid Rx path delay argument.\n");
+			return ERR_PTR(-EINVAL);
+		}
+	}
+
+	regmap_read(bsp_priv->regmap,
+		    macid == 0 ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR, &reg);
+	reg &= ~(NVT_TX_DELAY_MASK | NVT_RX_DELAY_MASK);
+
+	if (of_get_phy_mode(pdev->dev.of_node, &phy_mode)) {
+		dev_err(dev, "missing phy mode property\n");
+		return ERR_PTR(-EINVAL);
+	}
+
+	switch (phy_mode) {
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		reg &= ~NVT_MISCR_RMII;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		reg |= NVT_MISCR_RMII;
+		break;
+	default:
+		dev_err(dev, "Unsupported phy-mode (%d)\n", phy_mode);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!(reg & NVT_MISCR_RMII)) {
+		reg |= FIELD_PREP(NVT_TX_DELAY_MASK, tx_delay);
+		reg |= FIELD_PREP(NVT_RX_DELAY_MASK, rx_delay);
+	}
+
+	regmap_write(bsp_priv->regmap,
+		     macid == 0 ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR, reg);
+
+	bsp_priv->pdev = pdev;
+
+	return bsp_priv;
+}
+
+static int nvt_gmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	struct nvt_priv_data *priv_data;
+	int ret;
+
+	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+	if (ret)
+		return ret;
+
+	plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
+	if (IS_ERR(plat_dat))
+		return PTR_ERR(plat_dat);
+
+	/* Nuvoton DWMAC configs */
+	plat_dat->has_gmac = 1;
+	plat_dat->tx_fifo_size = 2048;
+	plat_dat->rx_fifo_size = 4096;
+	plat_dat->multicast_filter_bins = 0;
+	plat_dat->unicast_filter_entries = 8;
+	plat_dat->flags &= ~STMMAC_FLAG_USE_PHY_WOL;
+
+	priv_data = nvt_gmac_setup(pdev, plat_dat);
+	if (IS_ERR(priv_data))
+		return PTR_ERR(priv_data);
+
+	ret = stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
+	if (ret)
+		return ret;
+
+	/* The PMT flag is determined by the RWK property.
+	 * However, our hardware is configured to support only MGK.
+	 * This is an override on PMT to enable WoL capability.
+	 */
+	plat_dat->pmt = 1;
+	device_set_wakeup_capable(&pdev->dev, 1);
+
+	return 0;
+}
+
+static const struct of_device_id nvt_dwmac_match[] = {
+	{ .compatible = "nuvoton,ma35d1-dwmac"},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, nvt_dwmac_match);
+
+static struct platform_driver nvt_dwmac_driver = {
+	.probe  = nvt_gmac_probe,
+	.remove = stmmac_pltfr_remove,
+	.driver = {
+		.name           = "nuvoton-dwmac",
+		.pm		= &stmmac_pltfr_pm_ops,
+		.of_match_table = nvt_dwmac_match,
+	},
+};
+module_platform_driver(nvt_dwmac_driver);
+
+MODULE_AUTHOR("Joey Lu <yclu4@nuvoton.com>");
+MODULE_DESCRIPTION("Nuvoton DWMAC specific glue layer");
+MODULE_LICENSE("GPL v2");
-- 
2.34.1

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Paul Menzel]

Dear Joey,


Thank you for your patch.

Am 13.01.25 um 00:54 schrieb Joey Lu:
> Add support for Gigabit Ethernet on Nuvoton MA35 series using dwmac driver.

It’d be great if you added the datasheet name and revision to the commit 
message.

Also, please document how tested the driver. Maybe even paste new log 
messages.

> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
> Signed-off-by: Joey Lu <a0987203069@gmail.com>

As you use your company email address in the AUTHOR line below, please 
also add that email address to the commit message (and maybe even as the 
author).

> ---
>   drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
>   drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
>   .../ethernet/stmicro/stmmac/dwmac-nuvoton.c   | 179 ++++++++++++++++++
>   3 files changed, 191 insertions(+)
>   create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
> 
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> index 4cc85a36a1ab..2b424544cf6f 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
> +++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
> @@ -121,6 +121,17 @@ config DWMAC_MESON
>   	  the stmmac device driver. This driver is used for Meson6,
>   	  Meson8, Meson8b and GXBB SoCs.
>   
> +config DWMAC_NUVOTON
> +	tristate "Nuvoton MA35 dwmac support"
> +	default ARCH_MA35
> +	depends on OF && (ARCH_MA35 || COMPILE_TEST)
> +	select MFD_SYSCON
> +	help
> +	  Support for Ethernet controller on Nuvoton MA35 series SoC.
> +
> +	  This selects the Nuvoton MA35 series SoC glue layer support
> +	  for the stmmac device driver.

Also mention the module name `dwmac-nuvoton`?

> +
>   config DWMAC_QCOM_ETHQOS
>   	tristate "Qualcomm ETHQOS support"
>   	default ARCH_QCOM
> diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
> index b26f0e79c2b3..48e25b85ea06 100644
> --- a/drivers/net/ethernet/stmicro/stmmac/Makefile
> +++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
> @@ -19,6 +19,7 @@ obj-$(CONFIG_DWMAC_IPQ806X)	+= dwmac-ipq806x.o
>   obj-$(CONFIG_DWMAC_LPC18XX)	+= dwmac-lpc18xx.o
>   obj-$(CONFIG_DWMAC_MEDIATEK)	+= dwmac-mediatek.o
>   obj-$(CONFIG_DWMAC_MESON)	+= dwmac-meson.o dwmac-meson8b.o
> +obj-$(CONFIG_DWMAC_NUVOTON)	+= dwmac-nuvoton.o
>   obj-$(CONFIG_DWMAC_QCOM_ETHQOS)	+= dwmac-qcom-ethqos.o
>   obj-$(CONFIG_DWMAC_ROCKCHIP)	+= dwmac-rk.o
>   obj-$(CONFIG_DWMAC_RZN1)	+= dwmac-rzn1.o
> diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
> new file mode 100644
> index 000000000000..edf1b88ce1cd
> --- /dev/null
> +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
> @@ -0,0 +1,179 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Nuvoton DWMAC specific glue layer
> + *
> + * Copyright (C) 2024 Nuvoton Technology Corp.
> + *
> + * Author: Joey Lu <yclu4@nuvoton.com>
> + */
> +
> +#include <linux/mfd/syscon.h>
> +#include <linux/of_device.h>
> +#include <linux/of_net.h>
> +#include <linux/platform_device.h>
> +#include <linux/regmap.h>
> +#include <linux/stmmac.h>
> +
> +#include "stmmac.h"
> +#include "stmmac_platform.h"
> +
> +#define NVT_REG_SYS_GMAC0MISCR  0x108
> +#define NVT_REG_SYS_GMAC1MISCR  0x10C
> +
> +#define NVT_MISCR_RMII          BIT(0)
> +
> +/* 2000ps is mapped to 0x0 ~ 0xF */

Excuse my ignorance: What is ps?

> +#define NVT_PATH_DELAY_DEC      134
> +#define NVT_TX_DELAY_MASK       GENMASK(19, 16)
> +#define NVT_RX_DELAY_MASK       GENMASK(23, 20)
> +
> +struct nvt_priv_data {
> +	struct platform_device *pdev;
> +	struct regmap *regmap;
> +};
> +
> +static struct nvt_priv_data *
> +nvt_gmac_setup(struct platform_device *pdev, struct plat_stmmacenet_data *plat)
> +{
> +	struct device *dev = &pdev->dev;
> +	struct nvt_priv_data *bsp_priv;
> +	phy_interface_t phy_mode;
> +	u32 tx_delay, rx_delay;

Please append the unit to the variable name.

> +	u32 macid, arg, reg;
> +
> +	bsp_priv = devm_kzalloc(dev, sizeof(*bsp_priv), GFP_KERNEL);
> +	if (!bsp_priv)
> +		return ERR_PTR(-ENOMEM);
> +
> +	bsp_priv->regmap =
> +		syscon_regmap_lookup_by_phandle_args(dev->of_node, "nuvoton,sys", 1, &macid);
> +	if (IS_ERR(bsp_priv->regmap)) {
> +		dev_err_probe(dev, PTR_ERR(bsp_priv->regmap), "Failed to get sys register\n");
> +		return ERR_PTR(-ENODEV);
> +	}
> +	if (macid > 1) {
> +		dev_err_probe(dev, -EINVAL, "Invalid sys arguments\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	if (of_property_read_u32(dev->of_node, "tx-internal-delay-ps", &arg)) {
> +		tx_delay = 0;
> +	} else {
> +		if (arg <= 2000) {
> +			tx_delay = (arg == 2000) ? 0xF : (arg / NVT_PATH_DELAY_DEC);

Write hexcharacters lowercase?

> +			dev_dbg(dev, "Set Tx path delay to 0x%x\n", tx_delay);
> +		} else {
> +			dev_err(dev, "Invalid Tx path delay argument.\n");
> +			return ERR_PTR(-EINVAL);
> +		}
> +	}
> +	if (of_property_read_u32(dev->of_node, "rx-internal-delay-ps", &arg)) {
> +		rx_delay = 0;
> +	} else {
> +		if (arg <= 2000) {
> +			rx_delay = (arg == 2000) ? 0xF : (arg / NVT_PATH_DELAY_DEC);
> +			dev_dbg(dev, "Set Rx path delay to 0x%x\n", rx_delay);
> +		} else {
> +			dev_err(dev, "Invalid Rx path delay argument.\n");
> +			return ERR_PTR(-EINVAL);
> +		}
> +	}
> +
> +	regmap_read(bsp_priv->regmap,
> +		    macid == 0 ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR, &reg);
> +	reg &= ~(NVT_TX_DELAY_MASK | NVT_RX_DELAY_MASK);
> +
> +	if (of_get_phy_mode(pdev->dev.of_node, &phy_mode)) {
> +		dev_err(dev, "missing phy mode property\n");
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	switch (phy_mode) {
> +	case PHY_INTERFACE_MODE_RGMII:
> +	case PHY_INTERFACE_MODE_RGMII_ID:
> +	case PHY_INTERFACE_MODE_RGMII_RXID:
> +	case PHY_INTERFACE_MODE_RGMII_TXID:
> +		reg &= ~NVT_MISCR_RMII;
> +		break;
> +	case PHY_INTERFACE_MODE_RMII:
> +		reg |= NVT_MISCR_RMII;
> +		break;
> +	default:
> +		dev_err(dev, "Unsupported phy-mode (%d)\n", phy_mode);
> +		return ERR_PTR(-EINVAL);
> +	}
> +
> +	if (!(reg & NVT_MISCR_RMII)) {
> +		reg |= FIELD_PREP(NVT_TX_DELAY_MASK, tx_delay);
> +		reg |= FIELD_PREP(NVT_RX_DELAY_MASK, rx_delay);
> +	}
> +
> +	regmap_write(bsp_priv->regmap,
> +		     macid == 0 ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR, reg);
> +
> +	bsp_priv->pdev = pdev;
> +
> +	return bsp_priv;
> +}
> +
> +static int nvt_gmac_probe(struct platform_device *pdev)
> +{
> +	struct plat_stmmacenet_data *plat_dat;
> +	struct stmmac_resources stmmac_res;
> +	struct nvt_priv_data *priv_data;
> +	int ret;
> +
> +	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
> +	if (ret)
> +		return ret;
> +
> +	plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
> +	if (IS_ERR(plat_dat))
> +		return PTR_ERR(plat_dat);
> +
> +	/* Nuvoton DWMAC configs */
> +	plat_dat->has_gmac = 1;
> +	plat_dat->tx_fifo_size = 2048;
> +	plat_dat->rx_fifo_size = 4096;
> +	plat_dat->multicast_filter_bins = 0;
> +	plat_dat->unicast_filter_entries = 8;
> +	plat_dat->flags &= ~STMMAC_FLAG_USE_PHY_WOL;
> +
> +	priv_data = nvt_gmac_setup(pdev, plat_dat);
> +	if (IS_ERR(priv_data))
> +		return PTR_ERR(priv_data);
> +
> +	ret = stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
> +	if (ret)
> +		return ret;
> +
> +	/* The PMT flag is determined by the RWK property.
> +	 * However, our hardware is configured to support only MGK.
> +	 * This is an override on PMT to enable WoL capability.
> +	 */
> +	plat_dat->pmt = 1;
> +	device_set_wakeup_capable(&pdev->dev, 1);
> +
> +	return 0;
> +}
> +
> +static const struct of_device_id nvt_dwmac_match[] = {
> +	{ .compatible = "nuvoton,ma35d1-dwmac"},
> +	{ }
> +};
> +MODULE_DEVICE_TABLE(of, nvt_dwmac_match);
> +
> +static struct platform_driver nvt_dwmac_driver = {
> +	.probe  = nvt_gmac_probe,
> +	.remove = stmmac_pltfr_remove,
> +	.driver = {
> +		.name           = "nuvoton-dwmac",
> +		.pm		= &stmmac_pltfr_pm_ops,
> +		.of_match_table = nvt_dwmac_match,
> +	},
> +};
> +module_platform_driver(nvt_dwmac_driver);
> +
> +MODULE_AUTHOR("Joey Lu <yclu4@nuvoton.com>");

Maybe Nuvoton can set up a generic address?

> +MODULE_DESCRIPTION("Nuvoton DWMAC specific glue layer");
> +MODULE_LICENSE("GPL v2");


Kind regards,

Paul

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Andrew Lunn]

> > +#define NVT_MISCR_RMII          BIT(0)
> > +
> > +/* 2000ps is mapped to 0x0 ~ 0xF */
> 
> Excuse my ignorance: What is ps?

picoseconds. An RGMII link needs a 2ns delay between the clock line
and the data lines. Some MACs allow you to tune the delay they can
insert, in this case in steps of 2ns / 16.

> > +#define NVT_PATH_DELAY_DEC      134
> > +#define NVT_TX_DELAY_MASK       GENMASK(19, 16)
> > +#define NVT_RX_DELAY_MASK       GENMASK(23, 20)
> > +
> > +struct nvt_priv_data {
> > +	struct platform_device *pdev;
> > +	struct regmap *regmap;
> > +};
> > +
> > +static struct nvt_priv_data *
> > +nvt_gmac_setup(struct platform_device *pdev, struct plat_stmmacenet_data *plat)
> > +{
> > +	struct device *dev = &pdev->dev;
> > +	struct nvt_priv_data *bsp_priv;
> > +	phy_interface_t phy_mode;
> > +	u32 tx_delay, rx_delay;
> 
> Please append the unit to the variable name.

Which is trick, because they are in units of 2000/16 of a picosecond.

	Andrew

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Paul Menzel]

Dear Andrew,


Thank you for your quick reply.


Am 14.01.25 um 21:16 schrieb Andrew Lunn:
>>> +#define NVT_MISCR_RMII          BIT(0)
>>> +
>>> +/* 2000ps is mapped to 0x0 ~ 0xF */
>>
>> Excuse my ignorance: What is ps?
> 
> picoseconds. An RGMII link needs a 2ns delay between the clock line
> and the data lines. Some MACs allow you to tune the delay they can
> insert, in this case in steps of 2ns / 16.

Thank you for the clarification. Maybe it’s my English, but I didn’t 
deduce this from how the comment is worded. I do not have a better idea 
either.

>>> +#define NVT_PATH_DELAY_DEC      134
>>> +#define NVT_TX_DELAY_MASK       GENMASK(19, 16)
>>> +#define NVT_RX_DELAY_MASK       GENMASK(23, 20)
>>> +
>>> +struct nvt_priv_data {
>>> +	struct platform_device *pdev;
>>> +	struct regmap *regmap;
>>> +};
>>> +
>>> +static struct nvt_priv_data *
>>> +nvt_gmac_setup(struct platform_device *pdev, struct plat_stmmacenet_data *plat)
>>> +{
>>> +	struct device *dev = &pdev->dev;
>>> +	struct nvt_priv_data *bsp_priv;
>>> +	phy_interface_t phy_mode;
>>> +	u32 tx_delay, rx_delay;
>>
>> Please append the unit to the variable name.
> 
> Which is trick, because they are in units of 2000/16 of a picosecond.

Understood. Maybe a comment could be added?


Kind regards,

Paul

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Yanteng Si]

在 2025/1/14 10:21, Paul Menzel 写道:
> Dear Andrew,
> 
> 
> Thank you for your quick reply.
> 
> 
> Am 14.01.25 um 21:16 schrieb Andrew Lunn:
>>>> +#define NVT_MISCR_RMII          BIT(0)
>>>> +
>>>> +/* 2000ps is mapped to 0x0 ~ 0xF */
>>>
>>> Excuse my ignorance: What is ps?
>>
>> picoseconds. An RGMII link needs a 2ns delay between the clock line
>> and the data lines. Some MACs allow you to tune the delay they can
>> insert, in this case in steps of 2ns / 16.
> 
> Thank you for the clarification. Maybe it’s my English, but I didn’t 
> deduce this from how the comment is worded. I do not have a better idea 
> either.

Hmmm, how about:

2000 ps is xxxx

I checked the kernel code and it looks like
folks usually put a space between the number
and the unit.

I looked into the rules of a bunch of publishers
again. It seems like there's a rule about putting
a space between a number and a unit, but when the
unit is a symbol, that's an exception:

space:

10 kg
10 ℃
10 h

no space:

22°36′48″N, 114°10′10″E


Thanks,
Yanteng

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Jakub Kicinski]

On Mon, 13 Jan 2025 13:54:34 +0800 Joey Lu wrote:
> +	regmap_write(bsp_priv->regmap,
> +		     macid == 0 ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR, reg);

This is a pretty long line and you do it twice, so save the address 
to a temp variable, pls

> +MODULE_LICENSE("GPL v2");

checkpatch insists:

WARNING: Prefer "GPL" over "GPL v2" - see commit bf7fbeeae6db ("module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2" bogosity") 
-- 
pw-bot: cr

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Jakub Kicinski]

On Tue, 14 Jan 2025 02:49:31 +0100 Paul Menzel wrote:
> > +MODULE_AUTHOR("Joey Lu <yclu4@nuvoton.com>");  
> 
> Maybe Nuvoton can set up a generic address?

FWIW we prefer people to mailing lists in netdev.
Humans tend to have more of a sense of responsibility 
than corporations :S

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Joey Lu]

Dear Jakub,

Thank you for the reply.

Jakub Kicinski 於 1/15/2025 7:33 AM 寫道:
> On Mon, 13 Jan 2025 13:54:34 +0800 Joey Lu wrote:
>> +	regmap_write(bsp_priv->regmap,
>> +		     macid == 0 ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR, reg);
> This is a pretty long line and you do it twice, so save the address
> to a temp variable, pls
Got it!
>> +MODULE_LICENSE("GPL v2");
> checkpatch insists:
>
> WARNING: Prefer "GPL" over "GPL v2" - see commit bf7fbeeae6db ("module: Cure the MODULE_LICENSE "GPL" vs. "GPL v2" bogosity")

Understood. I will fix the warning.

BR,

Joey

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Paul Menzel]

Dear Joey,


Thank you for your prompt reply.


Am 15.01.25 um 10:03 schrieb Joey Lu:

> Paul Menzel 於 1/14/2025 9:49 AM 寫道:

[…]

>> Am 13.01.25 um 00:54 schrieb Joey Lu:
>>> Add support for Gigabit Ethernet on Nuvoton MA35 series using dwmac 
>>> driver.

[…]

>> Also, please document how tested the driver. Maybe even paste new log 
>> messages.
> 
> These are the kernel configurations for testing the MA35D1 GMAC driver: 
> ARCH_MA35, STMMAC_PLATFORM, DWMAC_NUVOTON.
> 
> I'm not sure if this information is sufficient, so please provide some 
> guidance on what else I should include to meet your requirements.

I’d be interested on what hardware you tested it. Probably some 
evaluation or customer reference board.

> I will include the log messages at the end of the email.

Awesome. Thank you. Personally, I also like to see those in the commit 
message.

>>> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
>>> Signed-off-by: Joey Lu <a0987203069@gmail.com>
>>
>> As you use your company email address in the AUTHOR line below, please 
>> also add that email address to the commit message (and maybe even as 
>> the author).
>
> I will update the AUTHOR to use my personal email address instead of the 
> company email.

Understood. (yclu4@nuvoton.com is also personal, but the Gmail address 
is private, I guess. ;-)).

For statistics, how companies contribute to the Linux kernel, having the 
company address somewhere would be nice though, as you are doing this as 
your work at Nuvoton, right?

>>> ---
>>>   drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
>>>   drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
>>>   .../ethernet/stmicro/stmmac/dwmac-nuvoton.c   | 179 ++++++++++++++++++
>>>   3 files changed, 191 insertions(+)
>>>   create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c

[…]

> log:
> 
> [    T0] Booting Linux on physical CPU 0x0000000000 [0x411fd040]

Out of curiosity, how do you get these timestamps T0, T1, …?

[…]


Thank you and kind regards,

Paul

Re: [PATCH net-next v7 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Joey Lu]

Dear Paul,

Thank you for your kind reply.

Paul Menzel 於 1/15/2025 5:22 PM 寫道:
> Dear Joey,
>
>
> Thank you for your prompt reply.
>
>
> Am 15.01.25 um 10:03 schrieb Joey Lu:
>
>> Paul Menzel 於 1/14/2025 9:49 AM 寫道:
>
> […]
>
>>> Am 13.01.25 um 00:54 schrieb Joey Lu:
>>>> Add support for Gigabit Ethernet on Nuvoton MA35 series using dwmac 
>>>> driver.
>
> […]
>
>>> Also, please document how tested the driver. Maybe even paste new 
>>> log messages.
>>
>> These are the kernel configurations for testing the MA35D1 GMAC 
>> driver: ARCH_MA35, STMMAC_PLATFORM, DWMAC_NUVOTON.
>>
>> I'm not sure if this information is sufficient, so please provide 
>> some guidance on what else I should include to meet your requirements.
>
> I’d be interested on what hardware you tested it. Probably some 
> evaluation or customer reference board.
The driver has been validated on our development boards, 
NuMaker-IoT-MA35D1-A1 and NuMaker-HMI-MA35D1-S1.
>
>> I will include the log messages at the end of the email.
>
> Awesome. Thank you. Personally, I also like to see those in the commit 
> message.
Understood. I will include in the commit message in the next patch.
>
>>>> Reviewed-by: Andrew Lunn <andrew@lunn.ch>
>>>> Signed-off-by: Joey Lu <a0987203069@gmail.com>
>>>
>>> As you use your company email address in the AUTHOR line below, 
>>> please also add that email address to the commit message (and maybe 
>>> even as the author).
>>
>> I will update the AUTHOR to use my personal email address instead of 
>> the company email.
>
> Understood. (yclu4@nuvoton.com is also personal, but the Gmail address 
> is private, I guess. ;-)).
Oops, I meant to say "private" instead.
>
> For statistics, how companies contribute to the Linux kernel, having 
> the company address somewhere would be nice though, as you are doing 
> this as your work at Nuvoton, right?
I will keep the company information in the driver header as you mentioned.
>
>>>> ---
>>>>   drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
>>>>   drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
>>>>   .../ethernet/stmicro/stmmac/dwmac-nuvoton.c   | 179 
>>>> ++++++++++++++++++
>>>>   3 files changed, 191 insertions(+)
>>>>   create mode 100644 
>>>> drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
>
> […]
>
>> log:
>>
>> [    T0] Booting Linux on physical CPU 0x0000000000 [0x411fd040]
>
> Out of curiosity, how do you get these timestamps T0, T1, …?
>
> […]
>
>
> Thank you and kind regards,
>
> Paul

I simply forgot to enable CONFIG_PRINTK_TIME. Here is what the log looks 
like after enabling it.

[    1.886100] nuvoton-dwmac 40120000.ethernet: TX Checksum insertion 
supported
[    1.893104] nuvoton-dwmac 40120000.ethernet: Enhanced/Alternate 
descriptors
[    1.900048] nuvoton-dwmac 40120000.ethernet: Enabled extended descriptors
[    1.906806] nuvoton-dwmac 40120000.ethernet: Ring mode enabled
[    1.912611] nuvoton-dwmac 40120000.ethernet: Enable RX Mitigation via 
HW Watchdog Timer

BR,

Joey