[PATCH v5 3/3] net: stmmac: dwmac-nuvoton: Add dwmac glue for Nuvoton MA35 family

[Joey Lu <a0987203069@gmail.com>]

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

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   | 182 ++++++++++++++++++
 3 files changed, 194 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 6658536a4e17..c8cbc0ec1311 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 2389fd261344..9812b824459f 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..c5b8933c1f44
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-nuvoton.c
@@ -0,0 +1,182 @@
+// 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 REG_SYS_GMAC0MISCR  0x108
+#define REG_SYS_GMAC1MISCR  0x10C
+
+#define MISCR_RMII          BIT(0)
+
+/* 2000ps is mapped to 0 ~ 0xF */
+#define PATH_DELAY_DEC      134
+#define TX_DELAY_OFFSET     16
+#define TX_DELAY_MASK       GENMASK(19, 16)
+#define RX_DELAY_OFFSET     20
+#define RX_DELAY_MASK       GENMASK(23, 20)
+
+struct nvt_priv_data {
+	struct platform_device *pdev;
+	struct regmap *regmap;
+};
+
+static struct nvt_priv_data *
+nuvoton_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; /* Default value is 0 */
+	} else {
+		if (arg <= 2000) {
+			tx_delay = (arg == 2000) ? 0xF : (arg / 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; /* Default value is 0 */
+	} else {
+		if (arg <= 2000) {
+			rx_delay = (arg == 2000) ? 0xF : (arg / 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 ? REG_SYS_GMAC0MISCR : REG_SYS_GMAC1MISCR, &reg);
+	reg &= ~(TX_DELAY_MASK | 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 &= ~MISCR_RMII;
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		reg |= MISCR_RMII;
+		break;
+	default:
+		dev_err(dev, "Unsupported phy-mode (%d)\n", phy_mode);
+		return ERR_PTR(-EINVAL);
+	}
+
+	if (!(reg & MISCR_RMII)) {
+		reg |= tx_delay << TX_DELAY_OFFSET;
+		reg |= rx_delay << RX_DELAY_OFFSET;
+	}
+
+	regmap_write(bsp_priv->regmap,
+		     macid == 0 ? REG_SYS_GMAC0MISCR : REG_SYS_GMAC1MISCR, reg);
+
+	bsp_priv->pdev = pdev;
+
+	return bsp_priv;
+}
+
+static int nuvoton_gmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	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;
+
+	plat_dat->bsp_priv = nuvoton_gmac_setup(pdev, plat_dat);
+	if (IS_ERR(plat_dat->bsp_priv)) {
+		ret = PTR_ERR(plat_dat->bsp_priv);
+		return ret;
+	}
+
+	ret = stmmac_dvr_probe(&pdev->dev, 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 nuvoton_dwmac_match[] = {
+	{ .compatible = "nuvoton,ma35d1-dwmac"},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, nuvoton_dwmac_match);
+
+static struct platform_driver nuvoton_dwmac_driver = {
+	.probe  = nuvoton_gmac_probe,
+	.remove = stmmac_pltfr_remove,
+	.driver = {
+		.name           = "nuvoton-dwmac",
+		.pm		= &stmmac_pltfr_pm_ops,
+		.of_match_table = nuvoton_dwmac_match,
+	},
+};
+module_platform_driver(nuvoton_dwmac_driver);
+
+MODULE_AUTHOR("Joey Lu <yclu4@nuvoton.com>");
+MODULE_DESCRIPTION("Nuvoton DWMAC specific glue layer");
+MODULE_LICENSE("GPL v2");
-- 
2.34.1