[PATCH v4 14/16] net: stmmac: dwmac-s32: add basic NXP S32G/S32R glue driver

[Jan Petrous via B4 Relay <devnull+jan.petrous.oss.nxp.com@kernel.org>]

From: "Jan Petrous (OSS)" <jan.petrous@oss.nxp.com>

NXP S32G2xx/S32G3xx and S32R45 are automotive grade SoCs
that integrate one or two Synopsys DWMAC 5.10/5.20 IPs.

The basic driver supports only RGMII interface.

Signed-off-by: Jan Petrous (OSS) <jan.petrous@oss.nxp.com>
---
 drivers/net/ethernet/stmicro/stmmac/Kconfig     |  12 ++
 drivers/net/ethernet/stmicro/stmmac/Makefile    |   1 +
 drivers/net/ethernet/stmicro/stmmac/dwmac-s32.c | 226 ++++++++++++++++++++++++
 3 files changed, 239 insertions(+)

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 05cc07b8f48c..a6579377bedb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -154,6 +154,18 @@ config DWMAC_RZN1
 	  the stmmac device driver. This support can make use of a custom MII
 	  converter PCS device.
 
+config DWMAC_S32
+	tristate "NXP S32G/S32R GMAC support"
+	default ARCH_S32
+	depends on OF && (ARCH_S32 || COMPILE_TEST)
+	help
+	  Support for ethernet controller on NXP S32CC SOCs.
+
+	  This selects NXP SoC glue layer support for the stmmac
+	  device driver. This driver is used for the S32CC series
+	  SOCs GMAC ethernet controller, ie. S32G2xx, S32G3xx and
+	  S32R45.
+
 config DWMAC_SOCFPGA
 	tristate "SOCFPGA dwmac support"
 	default ARCH_INTEL_SOCFPGA
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index c2f0e91f6bf8..1e87e2652c82 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -22,6 +22,7 @@ obj-$(CONFIG_DWMAC_MESON)	+= dwmac-meson.o dwmac-meson8b.o
 obj-$(CONFIG_DWMAC_QCOM_ETHQOS)	+= dwmac-qcom-ethqos.o
 obj-$(CONFIG_DWMAC_ROCKCHIP)	+= dwmac-rk.o
 obj-$(CONFIG_DWMAC_RZN1)	+= dwmac-rzn1.o
+obj-$(CONFIG_DWMAC_S32)		+= dwmac-s32.o
 obj-$(CONFIG_DWMAC_SOCFPGA)	+= dwmac-altr-socfpga.o
 obj-$(CONFIG_DWMAC_STARFIVE)	+= dwmac-starfive.o
 obj-$(CONFIG_DWMAC_STI)		+= dwmac-sti.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-s32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-s32.c
new file mode 100644
index 000000000000..fba221c37594
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-s32.c
@@ -0,0 +1,226 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * NXP S32G/R GMAC glue layer
+ *
+ * Copyright 2019-2024 NXP
+ *
+ */
+
+#include <linux/clk.h>
+#include <linux/clk-provider.h>
+#include <linux/device.h>
+#include <linux/ethtool.h>
+#include <linux/io.h>
+#include <linux/module.h>
+#include <linux/of_mdio.h>
+#include <linux/of_address.h>
+#include <linux/phy.h>
+#include <linux/phylink.h>
+#include <linux/platform_device.h>
+#include <linux/stmmac.h>
+
+#include "stmmac_platform.h"
+
+#define GMAC_TX_RATE_125M	125000000	/* 125MHz */
+#define GMAC_TX_RATE_25M	25000000	/* 25MHz */
+#define GMAC_TX_RATE_2M5	2500000		/* 2.5MHz */
+
+/* SoC PHY interface control register */
+#define PHY_INTF_SEL_MII        0x00
+#define PHY_INTF_SEL_SGMII      0x01
+#define PHY_INTF_SEL_RGMII      0x02
+#define PHY_INTF_SEL_RMII       0x08
+
+struct s32_priv_data {
+	void __iomem *ioaddr;
+	void __iomem *ctrl_sts;
+	struct device *dev;
+	phy_interface_t intf_mode;
+	struct clk *tx_clk;
+	struct clk *rx_clk;
+	bool rx_clk_enabled;
+};
+
+static int s32_gmac_write_phy_intf_select(struct s32_priv_data *gmac)
+{
+	u32 intf_sel;
+
+	switch (gmac->intf_mode) {
+	case PHY_INTERFACE_MODE_RGMII:
+	case PHY_INTERFACE_MODE_RGMII_ID:
+	case PHY_INTERFACE_MODE_RGMII_TXID:
+	case PHY_INTERFACE_MODE_RGMII_RXID:
+		intf_sel = PHY_INTF_SEL_RGMII;
+		break;
+	default:
+		dev_err(gmac->dev, "Unsupported PHY interface: %s\n",
+			phy_modes(gmac->intf_mode));
+		return -EINVAL;
+	}
+
+	writel(intf_sel, gmac->ctrl_sts);
+
+	dev_dbg(gmac->dev, "PHY mode set to %s\n", phy_modes(gmac->intf_mode));
+
+	return 0;
+}
+
+static int s32_gmac_init(struct platform_device *pdev, void *priv)
+{
+	struct s32_priv_data *gmac = priv;
+	int ret;
+
+	ret = clk_set_rate(gmac->tx_clk, GMAC_TX_RATE_125M);
+	if (!ret)
+		ret = clk_prepare_enable(gmac->tx_clk);
+
+	if (ret) {
+		dev_err(&pdev->dev, "Can't set tx clock\n");
+		return ret;
+	}
+
+	ret = clk_prepare_enable(gmac->rx_clk);
+	if (ret)
+		dev_dbg(&pdev->dev, "Can't set rx, clock source is disabled.\n");
+	else
+		gmac->rx_clk_enabled = true;
+
+	ret = s32_gmac_write_phy_intf_select(gmac);
+	if (ret) {
+		clk_disable_unprepare(gmac->tx_clk);
+		if (gmac->rx_clk_enabled) {
+			clk_disable_unprepare(gmac->rx_clk);
+			gmac->rx_clk_enabled = false;
+		}
+
+		dev_err(&pdev->dev, "Can't set PHY interface mode\n");
+		return ret;
+	}
+
+	return 0;
+}
+
+static void s32_gmac_exit(struct platform_device *pdev, void *priv)
+{
+	struct s32_priv_data *gmac = priv;
+
+	clk_disable_unprepare(gmac->tx_clk);
+
+	if (gmac->rx_clk_enabled) {
+		clk_disable_unprepare(gmac->rx_clk);
+		gmac->rx_clk_enabled = false;
+	}
+}
+
+static void s32_fix_mac_speed(void *priv, unsigned int speed, unsigned int mode)
+{
+	struct s32_priv_data *gmac = priv;
+	long tx_clk_rate;
+	int ret;
+
+	if (!gmac->rx_clk_enabled) {
+		ret = clk_prepare_enable(gmac->rx_clk);
+		if (ret) {
+			dev_err(gmac->dev, "Can't set rx clock\n");
+			return;
+		}
+		dev_dbg(gmac->dev, "rx clock enabled\n");
+		gmac->rx_clk_enabled = true;
+	}
+
+	tx_clk_rate = rgmii_clock(speed);
+	if (tx_clk_rate < 0) {
+		dev_err(gmac->dev, "Unsupported/Invalid speed: %d\n", speed);
+		return;
+	}
+
+	dev_dbg(gmac->dev, "Set tx clock to %ld Hz\n", tx_clk_rate);
+	ret = clk_set_rate(gmac->tx_clk, tx_clk_rate);
+	if (ret)
+		dev_err(gmac->dev, "Can't set tx clock\n");
+}
+
+static int s32_dwmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat;
+	struct device *dev = &pdev->dev;
+	struct s32_priv_data *gmac;
+	struct stmmac_resources res;
+	int ret;
+
+	gmac = devm_kzalloc(&pdev->dev, sizeof(*gmac), GFP_KERNEL);
+	if (!gmac)
+		return -ENOMEM;
+
+	gmac->dev = &pdev->dev;
+
+	ret = stmmac_get_platform_resources(pdev, &res);
+	if (ret)
+		return dev_err_probe(dev, ret,
+				     "Failed to get platform resources\n");
+
+	plat = devm_stmmac_probe_config_dt(pdev, res.mac);
+	if (IS_ERR(plat))
+		return dev_err_probe(dev, PTR_ERR(plat),
+				     "dt configuration failed\n");
+
+	/* PHY interface mode control reg */
+	gmac->ctrl_sts = devm_platform_get_and_ioremap_resource(pdev, 1, NULL);
+	if (IS_ERR(gmac->ctrl_sts))
+		return dev_err_probe(dev, PTR_ERR(gmac->ctrl_sts),
+				     "S32CC config region is missing\n");
+
+	/* tx clock */
+	gmac->tx_clk = devm_clk_get(&pdev->dev, "tx");
+	if (IS_ERR(gmac->tx_clk))
+		return dev_err_probe(dev, PTR_ERR(gmac->tx_clk),
+				     "tx clock not found\n");
+
+	/* rx clock */
+	gmac->rx_clk = devm_clk_get(&pdev->dev, "rx");
+	if (IS_ERR(gmac->rx_clk))
+		return dev_err_probe(dev, PTR_ERR(gmac->rx_clk),
+				     "rx clock not found\n");
+
+	gmac->intf_mode = plat->phy_interface;
+	gmac->ioaddr = res.addr;
+
+	/* S32CC core feature set */
+	plat->has_gmac4 = true;
+	plat->pmt = 1;
+	plat->flags |= STMMAC_FLAG_SPH_DISABLE;
+	plat->rx_fifo_size = 20480;
+	plat->tx_fifo_size = 20480;
+
+	plat->init = s32_gmac_init;
+	plat->exit = s32_gmac_exit;
+	plat->fix_mac_speed = s32_fix_mac_speed;
+
+	plat->bsp_priv = gmac;
+
+	return stmmac_pltfr_probe(pdev, plat, &res);
+}
+
+static const struct of_device_id s32_dwmac_match[] = {
+	{ .compatible = "nxp,s32g2-dwmac" },
+	{ .compatible = "nxp,s32g3-dwmac" },
+	{ .compatible = "nxp,s32r-dwmac" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, s32_dwmac_match);
+
+static struct platform_driver s32_dwmac_driver = {
+	.probe		= s32_dwmac_probe,
+	.remove		= stmmac_pltfr_remove,
+	.driver		= {
+			    .name		= "s32-dwmac",
+			    .pm		= &stmmac_pltfr_pm_ops,
+			    .of_match_table = s32_dwmac_match,
+	},
+};
+module_platform_driver(s32_dwmac_driver);
+
+MODULE_AUTHOR("Jan Petrous (OSS) <jan.petrous@oss.nxp.com>");
+MODULE_DESCRIPTION("NXP S32G/R common chassis GMAC driver");
+MODULE_LICENSE("GPL");
+

-- 
2.46.0