[PATCH net-next v13 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

Joey Lu
2026-03-04T23:21:53Z

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 | 12 ++
drivers/net/ethernet/stmicro/stmmac/Makefile | 1 +
.../ethernet/stmicro/stmmac/dwmac-nuvoton.c | 136 ++++++++++++++++++
3 files changed, 149 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 07088d03dbab..861f1c6c14f1 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 c9263987ef8d..4ade030b634f 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..80f1d7419d46
--- /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))
+ ret = dev_err_probe(dev, PTR_ERR(priv->regmap), "Failed to get sys register\n");
+
+ if (priv->macid > 1)
+ ret = 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");
--
2.43.0