[net-next,3/3] net: stmmac: add glue layer for T-HEAD TH1520 SoC

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 06c6871f8788..1bf71804c270 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -216,6 +216,17 @@  config DWMAC_SUN8I
 	  stmmac device driver. This driver is used for H3/A83T/A64
 	  EMAC ethernet controller.
 
+config DWMAC_THEAD
+	tristate "T-HEAD dwmac support"
+	depends on OF && (ARCH_THEAD || COMPILE_TEST)
+	select MFD_SYSCON
+	help
+	  Support for ethernet controllers on T-HEAD RISC-V SoCs
+
+	  This selects the T-HEAD platform specific glue layer support for
+	  the stmmac device driver. This driver is used for T-HEAD TH1520
+	  ethernet controller.
+
 config DWMAC_IMX8
 	tristate "NXP IMX8 DWMAC support"
 	default ARCH_MXC
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 5b57aee19267..d73171ed6ad7 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -27,6 +27,7 @@  obj-$(CONFIG_DWMAC_STI)		+= dwmac-sti.o
 obj-$(CONFIG_DWMAC_STM32)	+= dwmac-stm32.o
 obj-$(CONFIG_DWMAC_SUNXI)	+= dwmac-sunxi.o
 obj-$(CONFIG_DWMAC_SUN8I)	+= dwmac-sun8i.o
+obj-$(CONFIG_DWMAC_THEAD)	+= dwmac-thead.o
 obj-$(CONFIG_DWMAC_DWC_QOS_ETH)	+= dwmac-dwc-qos-eth.o
 obj-$(CONFIG_DWMAC_INTEL_PLAT)	+= dwmac-intel-plat.o
 obj-$(CONFIG_DWMAC_GENERIC)	+= dwmac-generic.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
new file mode 100644
index 000000000000..1a5a174b88ff
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-thead.c
@@ -0,0 +1,304 @@ 
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * T-HEAD DWMAC platform driver
+ *
+ * Copyright (C) 2023 Jisheng Zhang <jszhang@kernel.org>
+ * Copyright (C) 2021 Alibaba Group Holding Limited.
+ *
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "stmmac_platform.h"
+
+#define GMAC_CLK_EN			0x00
+#define  GMAC_TX_CLK_EN			BIT(1)
+#define  GMAC_TX_CLK_N_EN		BIT(2)
+#define  GMAC_TX_CLK_OUT_EN		BIT(3)
+#define  GMAC_RX_CLK_EN			BIT(4)
+#define  GMAC_RX_CLK_N_EN		BIT(5)
+#define  GMAC_EPHY_REF_CLK_EN		BIT(6)
+#define GMAC_RXCLK_DELAY_CTRL		0x04
+#define  GMAC_RXCLK_BYPASS		BIT(15)
+#define  GMAC_RXCLK_INVERT		BIT(14)
+#define  GMAC_RXCLK_DELAY_MASK		GENMASK(4, 0)
+#define  GMAC_RXCLK_DELAY_VAL(x)	FIELD_PREP(GMAC_RXCLK_DELAY_MASK, (x))
+#define GMAC_TXCLK_DELAY_CTRL		0x08
+#define  GMAC_TXCLK_BYPASS		BIT(15)
+#define  GMAC_TXCLK_INVERT		BIT(14)
+#define  GMAC_TXCLK_DELAY_MASK		GENMASK(4, 0)
+#define  GMAC_TXCLK_DELAY_VAL(x)	FIELD_PREP(GMAC_RXCLK_DELAY_MASK, (x))
+#define GMAC_PLLCLK_DIV			0x0c
+#define  GMAC_PLLCLK_DIV_EN		BIT(31)
+#define  GMAC_PLLCLK_DIV_MASK		GENMASK(7, 0)
+#define  GMAC_PLLCLK_DIV_NUM(x)		FIELD_PREP(GMAC_PLLCLK_DIV_MASK, (x))
+#define GMAC_GTXCLK_SEL			0x18
+#define  GMAC_GTXCLK_SEL_PLL		BIT(0)
+#define GMAC_INTF_CTRL			0x1c
+#define  PHY_INTF_MASK			BIT(0)
+#define  PHY_INTF_RGMII			FIELD_PREP(PHY_INTF_MASK, 1)
+#define  PHY_INTF_MII_GMII		FIELD_PREP(PHY_INTF_MASK, 0)
+#define GMAC_TXCLK_OEN			0x20
+#define  TXCLK_DIR_MASK			BIT(0)
+#define  TXCLK_DIR_OUTPUT		FIELD_PREP(TXCLK_DIR_MASK, 0)
+#define  TXCLK_DIR_INPUT		FIELD_PREP(TXCLK_DIR_MASK, 1)
+
+#define GMAC_GMII_RGMII_RATE	125000000
+#define GMAC_MII_RATE		25000000
+
+struct thead_dwmac {
+	struct plat_stmmacenet_data *plat;
+	struct regmap *apb_regmap;
+	struct device *dev;
+	struct clk *clk_axi;
+	u32 rx_delay;
+	u32 tx_delay;
+};
+
+static int thead_dwmac_set_phy_if(struct plat_stmmacenet_data *plat)
+{
+	struct thead_dwmac *dwmac = plat->bsp_priv;
+	u32 phyif;
+
+	switch (plat->interface) {
+	case PHY_INTERFACE_MODE_MII:
+		phyif = PHY_INTF_MII_GMII;
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		phyif = PHY_INTF_RGMII;
+		break;
+	default:
+		dev_err(dwmac->dev, "unsupported phy interface %d\n",
+			plat->interface);
+		return -EINVAL;
+	};
+
+	regmap_write(dwmac->apb_regmap, GMAC_INTF_CTRL, phyif);
+
+	return 0;
+}
+
+static int thead_dwmac_set_txclk_dir(struct plat_stmmacenet_data *plat)
+{
+	struct thead_dwmac *dwmac = plat->bsp_priv;
+	u32 txclk_dir;;
+
+	switch (plat->interface) {
+	case PHY_INTERFACE_MODE_MII:
+		txclk_dir = TXCLK_DIR_INPUT;
+		break;
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		txclk_dir = TXCLK_DIR_OUTPUT;
+		break;
+	default:
+		dev_err(dwmac->dev, "unsupported phy interface %d\n",
+			plat->interface);
+		return -EINVAL;
+	};
+
+	regmap_write(dwmac->apb_regmap, GMAC_TXCLK_OEN, txclk_dir);
+
+	return 0;
+}
+
+static void thead_dwmac_fix_speed(void *priv, unsigned int speed, unsigned int mode)
+{
+	struct thead_dwmac *dwmac = priv;
+	struct plat_stmmacenet_data *plat = dwmac->plat;
+	unsigned long rate;
+	u32 div;
+
+	switch (plat->interface) {
+	/* For MII, rxc/txc is provided by phy */
+	case PHY_INTERFACE_MODE_MII:
+		return;
+
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		rate = clk_get_rate(plat->stmmac_clk);
+		if (!rate || rate % GMAC_GMII_RGMII_RATE != 0 ||
+		    rate % GMAC_MII_RATE != 0) {
+			dev_err(dwmac->dev, "invalid gmac rate %ld\n", rate);
+			return;
+		}
+
+		regmap_update_bits(dwmac->apb_regmap, GMAC_PLLCLK_DIV, GMAC_PLLCLK_DIV_EN, 0);
+
+		switch (speed) {
+		case SPEED_1000:
+			div = rate / GMAC_GMII_RGMII_RATE;
+			break;
+		case SPEED_100:
+			div = rate / GMAC_MII_RATE;
+			break;
+		case SPEED_10:
+			div = rate * 10 / GMAC_MII_RATE;
+			break;
+		default:
+			dev_err(dwmac->dev, "invalid speed %u\n", speed);
+			break;
+		}
+		regmap_update_bits(dwmac->apb_regmap, GMAC_PLLCLK_DIV,
+				   GMAC_PLLCLK_DIV_MASK, GMAC_PLLCLK_DIV_NUM(div));
+
+		regmap_update_bits(dwmac->apb_regmap, GMAC_PLLCLK_DIV,
+				   GMAC_PLLCLK_DIV_EN, GMAC_PLLCLK_DIV_EN);
+		break;
+	default:
+		dev_err(dwmac->dev, "unsupported phy interface %d\n",
+			plat->interface);
+		return;
+	}
+}
+
+static int thead_dwmac_enable_clk(struct plat_stmmacenet_data *plat)
+{
+	struct thead_dwmac *dwmac = plat->bsp_priv;
+	u32 reg;
+
+	switch (plat->interface) {
+	case PHY_INTERFACE_MODE_MII:
+		reg = GMAC_RX_CLK_EN | GMAC_TX_CLK_EN;
+		break;
+
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+		/* use pll */
+		regmap_write(dwmac->apb_regmap, GMAC_GTXCLK_SEL, GMAC_GTXCLK_SEL_PLL);
+
+		reg = GMAC_TX_CLK_EN | GMAC_TX_CLK_N_EN | GMAC_TX_CLK_OUT_EN |
+		      GMAC_RX_CLK_EN | GMAC_RX_CLK_N_EN;
+		break;
+
+	default:
+		dev_err(dwmac->dev, "unsupported phy interface %d\n",
+			plat->interface);
+		return -EINVAL;
+	}
+
+	regmap_write(dwmac->apb_regmap, GMAC_CLK_EN, reg);
+
+	return 0;
+}
+
+static int thead_dwmac_init(struct platform_device *pdev,
+			    struct plat_stmmacenet_data *plat)
+{
+	struct thead_dwmac *dwmac = plat->bsp_priv;
+	int ret;
+
+	ret = thead_dwmac_set_phy_if(plat);
+	if (ret)
+		return ret;
+
+	ret = thead_dwmac_set_txclk_dir(plat);
+	if (ret)
+		return ret;
+
+	regmap_write(dwmac->apb_regmap, GMAC_RXCLK_DELAY_CTRL,
+		     GMAC_RXCLK_DELAY_VAL(dwmac->rx_delay));
+	regmap_write(dwmac->apb_regmap, GMAC_TXCLK_DELAY_CTRL,
+		     GMAC_TXCLK_DELAY_VAL(dwmac->tx_delay));
+
+	thead_dwmac_fix_speed(dwmac, SPEED_1000, 0);
+
+	return thead_dwmac_enable_clk(plat);
+}
+
+static int thead_dwmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat;
+	struct stmmac_resources stmmac_res;
+	struct thead_dwmac *dwmac;
+	struct device_node *np = pdev->dev.of_node;
+	u32 delay_ps;
+	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 = stmmac_probe_config_dt(pdev, stmmac_res.mac);
+	if (IS_ERR(plat))
+		return dev_err_probe(&pdev->dev, PTR_ERR(plat),
+				     "dt configuration failed\n");
+
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+	if (!dwmac)
+		return -ENOMEM;
+
+	dwmac->clk_axi = devm_clk_get_enabled(&pdev->dev, "axi");
+	if (IS_ERR(dwmac->clk_axi))
+		return dev_err_probe(&pdev->dev, PTR_ERR(dwmac->clk_axi),
+				     "error getting axi clock\n");
+
+	if (!of_property_read_u32(np, "rx-internal-delay-ps", &delay_ps))
+		dwmac->rx_delay = delay_ps;
+	if (!of_property_read_u32(np, "tx-internal-delay-ps", &delay_ps))
+		dwmac->tx_delay = delay_ps;
+
+	dwmac->apb_regmap = syscon_regmap_lookup_by_phandle(np, "thead,gmacapb");
+	if (IS_ERR(dwmac->apb_regmap)) {
+		dev_err(&pdev->dev, "Failed to get gmac apb syscon\n");
+		return PTR_ERR(dwmac->apb_regmap);
+	}
+
+	dwmac->dev = &pdev->dev;
+	dwmac->plat = plat;
+	plat->bsp_priv = dwmac;
+	plat->fix_mac_speed = thead_dwmac_fix_speed;
+
+	ret = thead_dwmac_init(pdev, plat);
+	if (ret)
+		goto err_dvr_probe;
+
+	ret = stmmac_dvr_probe(&pdev->dev, plat, &stmmac_res);
+	if (ret)
+		goto err_dvr_probe;
+
+	return 0;
+
+err_dvr_probe:
+	stmmac_remove_config_dt(pdev, plat);
+
+	return ret;
+}
+
+static const struct of_device_id thead_dwmac_match[] = {
+	{ .compatible = "thead,th1520-dwmac" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, thead_dwmac_match);
+
+static struct platform_driver thead_dwmac_driver = {
+	.probe = thead_dwmac_probe,
+	.remove_new = stmmac_pltfr_remove,
+	.driver = {
+		.name = "thead-dwmac",
+		.pm = &stmmac_pltfr_pm_ops,
+		.of_match_table = thead_dwmac_match,
+	},
+};
+module_platform_driver(thead_dwmac_driver);
+
+MODULE_AUTHOR("T-HEAD");
+MODULE_AUTHOR("Jisheng Zhang <jszhang@kernel.org>");
+MODULE_DESCRIPTION("T-HEAD dwmac platform driver");
+MODULE_LICENSE("GPL");