Merge branch 'add-support-for-nuvoton-ma35d1-gmac'

Joey Lu says:

====================
Add support for Nuvoton MA35D1 GMAC

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.
====================

Link: https://patch.msgid.link/20260323101756.81849-1-a0987203069@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

5 files changed, 290 insertions, 0 deletions

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..ab18702e53f9
--- /dev/null
+++ b/Documentation/devicetree/bindings/net/nuvoton,ma35d1-dwmac.yaml
@@ -0,0 +1,140 @@
+# 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).
+
+select:
+  properties:
+    compatible:
+      contains:
+        enum:
+          - nuvoton,ma35d1-dwmac
+  required:
+    - compatible
+
+allOf:
+  - $ref: snps,dwmac.yaml#
+
+properties:
+  compatible:
+    items:
+      - const: nuvoton,ma35d1-dwmac
+      - const: snps,dwmac-3.70a
+
+  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
+  - phy-mode
+
+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", "snps,dwmac-3.70a";
+        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";
+        snps,multicast-filter-bins = <0>;
+        snps,perfect-filter-entries = <8>;
+        rx-fifo-depth = <4096>;
+        tx-fifo-depth = <2048>;
+
+        phy-mode = "rgmii-id";
+        phy-handle = <&eth_phy0>;
+        mdio {
+            compatible = "snps,dwmac-mdio";
+            #address-cells = <1>;
+            #size-cells = <0>;
+
+            eth_phy0: ethernet-phy@0 {
+                reg = <0>;
+            };
+        };
+    };
diff --git a/Documentation/devicetree/bindings/net/snps,dwmac.yaml b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
index 98ebb6276bc6..c25903c74484 100644
--- a/Documentation/devicetree/bindings/net/snps,dwmac.yaml
+++ b/Documentation/devicetree/bindings/net/snps,dwmac.yaml
@@ -69,6 +69,7 @@ properties:
         - ingenic,x2000-mac
         - loongson,ls2k-dwmac
         - loongson,ls7a-dwmac
+        - nuvoton,ma35d1-dwmac
         - nxp,s32g2-dwmac
         - qcom,qcs404-ethqos
         - qcom,sa8775p-ethqos
diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index d3a6ab7383fc..c2cb530fd0a2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -132,6 +132,18 @@ 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. The nuvoton-dwmac driver is
+	  used for MA35 series SoCs.
+
 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 945c5354eced..a1cea2f57252 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -20,6 +20,7 @@ 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-$(CONFIG_DWMAC_RENESAS_GBETH) += dwmac-renesas-gbeth.o
 obj-$(CONFIG_DWMAC_ROCKCHIP)	+= dwmac-rk.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..e2240b68ad98
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Nuvoton DWMAC specific glue layer
+ *
+ * Copyright (C) 2025 Nuvoton Technology Corp.
+ *
+ * Author: Joey Lu <a0987203069@gmail.com>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/mod_devicetable.h>
+#include <linux/of.h>
+#include <linux/of_net.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+#include <linux/stmmac.h>
+
+#include "stmmac_platform.h"
+
+#define NVT_REG_SYS_GMAC0MISCR  0x108
+#define NVT_REG_SYS_GMAC1MISCR  0x10C
+
+#define NVT_MISCR_RMII          BIT(0)
+
+/* Two thousand picoseconds are evenly mapped to a 4-bit field,
+ * resulting in each step being 2000/15 picoseconds.
+ */
+#define NVT_PATH_DELAY_STEP     134
+#define NVT_TX_DELAY_MASK       GENMASK(19, 16)
+#define NVT_RX_DELAY_MASK       GENMASK(23, 20)
+
+struct nvt_priv_data {
+	struct device *dev;
+	struct regmap *regmap;
+	u32 macid;
+};
+
+static int nvt_gmac_get_delay(struct device *dev, const char *property)
+{
+	u32 arg;
+
+	if (of_property_read_u32(dev->of_node, property, &arg))
+		return 0;
+
+	if (arg > 2000)
+		return -EINVAL;
+
+	if (arg == 2000)
+		return 15;
+
+	return arg / NVT_PATH_DELAY_STEP;
+}
+
+static int nvt_set_phy_intf_sel(void *bsp_priv, u8 phy_intf_sel)
+{
+	struct nvt_priv_data *priv = bsp_priv;
+	u32 reg, val;
+	int ret;
+
+	if (phy_intf_sel == PHY_INTF_SEL_RGMII) {
+		ret = nvt_gmac_get_delay(priv->dev, "rx-internal-delay-ps");
+		if (ret < 0)
+			return ret;
+		val = FIELD_PREP(NVT_RX_DELAY_MASK, ret);
+
+		ret = nvt_gmac_get_delay(priv->dev, "tx-internal-delay-ps");
+		if (ret < 0)
+			return ret;
+		val |= FIELD_PREP(NVT_TX_DELAY_MASK, ret);
+	} else if (phy_intf_sel == PHY_INTF_SEL_RMII) {
+		val = NVT_MISCR_RMII;
+	} else {
+		return -EINVAL;
+	}
+
+	reg = (priv->macid == 0) ? NVT_REG_SYS_GMAC0MISCR : NVT_REG_SYS_GMAC1MISCR;
+	regmap_update_bits(priv->regmap, reg,
+			   NVT_RX_DELAY_MASK | NVT_TX_DELAY_MASK | NVT_MISCR_RMII, val);
+
+	return 0;
+}
+
+static int nvt_gmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	struct device *dev = &pdev->dev;
+	struct nvt_priv_data *priv;
+	int ret;
+
+	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to get platform resources\n");
+
+	plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
+	if (IS_ERR(plat_dat))
+		return dev_err_probe(dev, PTR_ERR(plat_dat), "Failed to get platform data\n");
+
+	priv = devm_kzalloc(dev, sizeof(*priv), GFP_KERNEL);
+	if (!priv)
+		return dev_err_probe(dev, -ENOMEM, "Failed to allocate private data\n");
+
+	priv->regmap = syscon_regmap_lookup_by_phandle_args(dev->of_node, "nuvoton,sys",
+							    1, &priv->macid);
+	if (IS_ERR(priv->regmap))
+		return dev_err_probe(dev, PTR_ERR(priv->regmap), "Failed to get sys register\n");
+
+	if (priv->macid > 1)
+		return dev_err_probe(dev, -EINVAL, "Invalid sys arguments\n");
+
+	plat_dat->bsp_priv = priv;
+	plat_dat->set_phy_intf_sel = nvt_set_phy_intf_sel;
+
+	return stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
+}
+
+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 <a0987203069@gmail.com>");
+MODULE_DESCRIPTION("Nuvoton DWMAC specific glue layer");
+MODULE_LICENSE("GPL");