Adds Sophgo dwmac driver support on the Sophgo SG2044 SoC.

Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
---
 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 ++
 drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
 .../ethernet/stmicro/stmmac/dwmac-sophgo.c    | 105 ++++++++++++++++++
 3 files changed, 117 insertions(+)
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-sophgo.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 05cc07b8f48c..bc44b21c593f 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -169,6 +169,17 @@ config DWMAC_SOCFPGA
 	  for the stmmac device driver. This driver is used for
 	  arria5 and cyclone5 FPGA SoCs.
 
+config DWMAC_SOPHGO
+	tristate "Sophgo dwmac support"
+	depends on OF && (ARCH_SOPHGO || COMPILE_TEST)
+	default m if ARCH_SOPHGO
+	help
+	  Support for ethernet controllers on Sophgo RISC-V SoCs
+
+	  This selects the Sophgo SoC specific glue layer support
+	  for the stmmac device driver. This driver is used for the
+	  ethernet controllers on various Sophgo SoCs.
+
 config DWMAC_STARFIVE
 	tristate "StarFive dwmac support"
 	depends on OF && (ARCH_STARFIVE || COMPILE_TEST)
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index c2f0e91f6bf8..e1287b53047b 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -23,6 +23,7 @@ obj-$(CONFIG_DWMAC_QCOM_ETHQOS)	+= dwmac-qcom-ethqos.o
 obj-$(CONFIG_DWMAC_ROCKCHIP)	+= dwmac-rk.o
 obj-$(CONFIG_DWMAC_RZN1)	+= dwmac-rzn1.o
 obj-$(CONFIG_DWMAC_SOCFPGA)	+= dwmac-altr-socfpga.o
+obj-$(CONFIG_DWMAC_SOPHGO)	+= dwmac-sophgo.o
 obj-$(CONFIG_DWMAC_STARFIVE)	+= dwmac-starfive.o
 obj-$(CONFIG_DWMAC_STI)		+= dwmac-sti.o
 obj-$(CONFIG_DWMAC_STM32)	+= dwmac-stm32.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-sophgo.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-sophgo.c
new file mode 100644
index 000000000000..a4997cc0294a
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-sophgo.c
@@ -0,0 +1,105 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Sophgo DWMAC platform driver
+ *
+ * Copyright (C) 2024 Inochi Amaoto <inochiama@gmail.com>
+ */
+
+#include <linux/bits.h>
+#include <linux/mod_devicetable.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+
+#include "stmmac_platform.h"
+
+struct sophgo_dwmac {
+	struct device *dev;
+	struct clk *clk_tx;
+};
+
+static void sophgo_dwmac_fix_mac_speed(void *priv, unsigned int speed, unsigned int mode)
+{
+	struct sophgo_dwmac *dwmac = priv;
+	long rate;
+	int ret;
+
+	rate = rgmii_clock(speed);
+	if (rate < 0) {
+		dev_err(dwmac->dev, "invalid speed %u\n", speed);
+		return;
+	}
+
+	ret = clk_set_rate(dwmac->clk_tx, rate);
+	if (ret)
+		dev_err(dwmac->dev, "failed to set tx rate %lu: %pe\n",
+			rate, ERR_PTR(ret));
+}
+
+static int sophgo_sg2044_dwmac_init(struct platform_device *pdev,
+				    struct plat_stmmacenet_data *plat_dat,
+				    struct stmmac_resources *stmmac_res)
+{
+	struct sophgo_dwmac *dwmac;
+
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+	if (!dwmac)
+		return -ENOMEM;
+
+	dwmac->clk_tx = devm_clk_get_enabled(&pdev->dev, "tx");
+	if (IS_ERR(dwmac->clk_tx))
+		return dev_err_probe(&pdev->dev, PTR_ERR(dwmac->clk_tx),
+				     "failed to get tx clock\n");
+
+	dwmac->dev = &pdev->dev;
+	plat_dat->bsp_priv = dwmac;
+	plat_dat->flags |= STMMAC_FLAG_SPH_DISABLE;
+	plat_dat->fix_mac_speed = sophgo_dwmac_fix_mac_speed;
+	plat_dat->multicast_filter_bins = 0;
+	plat_dat->unicast_filter_entries = 1;
+
+	return 0;
+}
+
+static int sophgo_dwmac_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 dev_err_probe(&pdev->dev, ret,
+				     "failed to get resources\n");
+
+	plat_dat = devm_stmmac_probe_config_dt(pdev, stmmac_res.mac);
+	if (IS_ERR(plat_dat))
+		return dev_err_probe(&pdev->dev, PTR_ERR(plat_dat),
+				     "dt configuration failed\n");
+
+	ret = sophgo_sg2044_dwmac_init(pdev, plat_dat, &stmmac_res);
+	if (ret)
+		return ret;
+
+	return stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
+}
+
+static const struct of_device_id sophgo_dwmac_match[] = {
+	{ .compatible = "sophgo,sg2044-dwmac" },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, sophgo_dwmac_match);
+
+static struct platform_driver sophgo_dwmac_driver = {
+	.probe  = sophgo_dwmac_probe,
+	.remove = stmmac_pltfr_remove,
+	.driver = {
+		.name = "sophgo-dwmac",
+		.pm = &stmmac_pltfr_pm_ops,
+		.of_match_table = sophgo_dwmac_match,
+	},
+};
+module_platform_driver(sophgo_dwmac_driver);
+
+MODULE_AUTHOR("Inochi Amaoto <inochiama@gmail.com>");
+MODULE_DESCRIPTION("Sophgo DWMAC platform driver");
+MODULE_LICENSE("GPL");
-- 
2.47.0