[PATCH v2 3/4] net: stmmac: Add glue layer for Loongson-1 SoC

[Keguang Zhang]

This glue driver is created based on the arch-code
implemented earlier with the platform-specific settings.

Use syscon for SYSCON register access.

Partialy based on the previous work by Serge Semin.

Signed-off-by: Keguang Zhang <keguang.zhang@xxxxxxxxx>
---
V1 -> V2: Fix the build errors due to CONFIG_OF being unset
          Change struct reg_field definitions to const
          Rename the syscon property to "loongson,dwmac-syscon"
          Add MII PHY mode for LS1C

 drivers/net/ethernet/stmicro/stmmac/Kconfig   |  11 +
 drivers/net/ethernet/stmicro/stmmac/Makefile  |   1 +
 .../ethernet/stmicro/stmmac/dwmac-loongson1.c | 273 ++++++++++++++++++
 3 files changed, 285 insertions(+)
 create mode 100644 drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index 06c6871f8788..a2b9e289aa36 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -239,6 +239,17 @@ config DWMAC_INTEL_PLAT
 	  the stmmac device driver. This driver is used for the Intel Keem Bay
 	  SoC.
 
+config DWMAC_LOONGSON1
+	tristate "Loongson1 GMAC support"
+	default MACH_LOONGSON32
+	depends on OF && (MACH_LOONGSON32 || COMPILE_TEST)
+	help
+	  Support for ethernet controller on Loongson1 SoC.
+
+	  This selects Loongson1 SoC glue layer support for the stmmac
+	  device driver. This driver is used for Loongson1-based boards
+	  like Loongson LS1B/LS1C.
+
 config DWMAC_TEGRA
 	tristate "NVIDIA Tegra MGBE support"
 	depends on ARCH_TEGRA || COMPILE_TEST
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index 5b57aee19267..80e598bd4255 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -29,6 +29,7 @@ obj-$(CONFIG_DWMAC_SUNXI)	+= dwmac-sunxi.o
 obj-$(CONFIG_DWMAC_SUN8I)	+= dwmac-sun8i.o
 obj-$(CONFIG_DWMAC_DWC_QOS_ETH)	+= dwmac-dwc-qos-eth.o
 obj-$(CONFIG_DWMAC_INTEL_PLAT)	+= dwmac-intel-plat.o
+obj-$(CONFIG_DWMAC_LOONGSON1)	+= dwmac-loongson1.o
 obj-$(CONFIG_DWMAC_GENERIC)	+= dwmac-generic.o
 obj-$(CONFIG_DWMAC_IMX8)	+= dwmac-imx.o
 obj-$(CONFIG_DWMAC_TEGRA)	+= dwmac-tegra.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c
new file mode 100644
index 000000000000..5210b5e8ae47
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-loongson1.c
@@ -0,0 +1,273 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Loongson-1 DWMAC glue layer
+ *
+ * Copyright (C) 2011-2023 Keguang Zhang <keguang.zhang@xxxxxxxxx>
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/phy.h>
+#include <linux/platform_device.h>
+#include <linux/regmap.h>
+
+#include "stmmac.h"
+#include "stmmac_platform.h"
+
+/* Loongson-1 SYSCON Registers */
+#define LS1X_SYSCON0		(0x0)
+#define LS1X_SYSCON1		(0x4)
+
+struct ls1x_dwmac_syscon {
+	const struct reg_field *reg_fields;
+	unsigned int nr_reg_fields;
+	int (*syscon_init)(struct plat_stmmacenet_data *plat);
+};
+
+struct ls1x_dwmac {
+	struct device *dev;
+	struct plat_stmmacenet_data *plat_dat;
+	const struct ls1x_dwmac_syscon *syscon;
+	struct regmap *regmap;
+	struct regmap_field *regmap_fields[];
+};
+
+enum ls1b_dwmac_syscon_regfield {
+	GMAC1_USE_UART1,
+	GMAC1_USE_UART0,
+	GMAC1_SHUT,
+	GMAC0_SHUT,
+	GMAC1_USE_TXCLK,
+	GMAC0_USE_TXCLK,
+	GMAC1_USE_PWM23,
+	GMAC0_USE_PWM01,
+};
+
+enum ls1c_dwmac_syscon_regfield {
+	GMAC_SHUT,
+	PHY_INTF_SELI,
+};
+
+static const struct reg_field ls1b_dwmac_syscon_regfields[] = {
+	[GMAC1_USE_UART1]	= REG_FIELD(LS1X_SYSCON0, 4, 4),
+	[GMAC1_USE_UART0]	= REG_FIELD(LS1X_SYSCON0, 3, 3),
+	[GMAC1_SHUT]		= REG_FIELD(LS1X_SYSCON1, 13, 13),
+	[GMAC0_SHUT]		= REG_FIELD(LS1X_SYSCON1, 12, 12),
+	[GMAC1_USE_TXCLK]	= REG_FIELD(LS1X_SYSCON1, 3, 3),
+	[GMAC0_USE_TXCLK]	= REG_FIELD(LS1X_SYSCON1, 2, 2),
+	[GMAC1_USE_PWM23]	= REG_FIELD(LS1X_SYSCON1, 1, 1),
+	[GMAC0_USE_PWM01]	= REG_FIELD(LS1X_SYSCON1, 0, 0)
+};
+
+static const struct reg_field ls1c_dwmac_syscon_regfields[] = {
+	[GMAC_SHUT]		= REG_FIELD(LS1X_SYSCON0, 6, 6),
+	[PHY_INTF_SELI]		= REG_FIELD(LS1X_SYSCON1, 28, 30)
+};
+
+static int ls1b_dwmac_syscon_init(struct plat_stmmacenet_data *plat)
+{
+	struct ls1x_dwmac *dwmac = plat->bsp_priv;
+	struct regmap_field **regmap_fields = dwmac->regmap_fields;
+
+	if (plat->bus_id) {
+		regmap_field_write(regmap_fields[GMAC1_USE_UART1], 1);
+		regmap_field_write(regmap_fields[GMAC1_USE_UART0], 1);
+
+		switch (plat->phy_interface) {
+		case PHY_INTERFACE_MODE_RGMII:
+			regmap_field_write(regmap_fields[GMAC1_USE_TXCLK], 0);
+			regmap_field_write(regmap_fields[GMAC1_USE_PWM23], 0);
+			break;
+		case PHY_INTERFACE_MODE_MII:
+			regmap_field_write(regmap_fields[GMAC1_USE_TXCLK], 1);
+			regmap_field_write(regmap_fields[GMAC1_USE_PWM23], 1);
+			break;
+		default:
+			dev_err(dwmac->dev, "Unsupported PHY mode %u\n",
+				plat->phy_interface);
+			return -EOPNOTSUPP;
+		}
+
+		regmap_field_write(regmap_fields[GMAC1_SHUT], 0);
+	} else {
+		switch (plat->phy_interface) {
+		case PHY_INTERFACE_MODE_RGMII:
+			regmap_field_write(regmap_fields[GMAC0_USE_TXCLK], 0);
+			regmap_field_write(regmap_fields[GMAC0_USE_PWM01], 0);
+			break;
+		case PHY_INTERFACE_MODE_MII:
+			regmap_field_write(regmap_fields[GMAC0_USE_TXCLK], 1);
+			regmap_field_write(regmap_fields[GMAC0_USE_PWM01], 1);
+			break;
+		default:
+			dev_err(dwmac->dev, "Unsupported PHY mode %u\n",
+				plat->phy_interface);
+			return -EOPNOTSUPP;
+		}
+
+		regmap_field_write(regmap_fields[GMAC0_SHUT], 0);
+	}
+
+	return 0;
+}
+
+static int ls1c_dwmac_syscon_init(struct plat_stmmacenet_data *plat)
+{
+	struct ls1x_dwmac *dwmac = plat->bsp_priv;
+	struct regmap_field **regmap_fields = dwmac->regmap_fields;
+
+	switch (plat->phy_interface) {
+	case PHY_INTERFACE_MODE_MII:
+		regmap_field_write(regmap_fields[PHY_INTF_SELI], 0);
+		break;
+	case PHY_INTERFACE_MODE_RMII:
+		regmap_field_write(regmap_fields[PHY_INTF_SELI], 4);
+		break;
+	default:
+		dev_err(dwmac->dev, "Unsupported PHY-mode %u\n",
+			plat->phy_interface);
+		return -EOPNOTSUPP;
+	}
+
+	regmap_field_write(regmap_fields[GMAC_SHUT], 0);
+
+	return 0;
+}
+
+static const struct ls1x_dwmac_syscon ls1b_dwmac_syscon = {
+	.reg_fields = ls1b_dwmac_syscon_regfields,
+	.nr_reg_fields = ARRAY_SIZE(ls1b_dwmac_syscon_regfields),
+	.syscon_init = ls1b_dwmac_syscon_init,
+};
+
+static const struct ls1x_dwmac_syscon ls1c_dwmac_syscon = {
+	.reg_fields = ls1c_dwmac_syscon_regfields,
+	.nr_reg_fields = ARRAY_SIZE(ls1c_dwmac_syscon_regfields),
+	.syscon_init = ls1c_dwmac_syscon_init,
+};
+
+static int ls1x_dwmac_init(struct platform_device *pdev, void *priv)
+{
+	struct ls1x_dwmac *dwmac = priv;
+	int ret;
+
+	ret = devm_regmap_field_bulk_alloc(dwmac->dev, dwmac->regmap,
+					   dwmac->regmap_fields,
+					   dwmac->syscon->reg_fields,
+					   dwmac->syscon->nr_reg_fields);
+	if (ret)
+		return ret;
+
+	if (dwmac->syscon->syscon_init) {
+		ret = dwmac->syscon->syscon_init(dwmac->plat_dat);
+		if (ret)
+			return ret;
+	}
+
+	return 0;
+}
+
+static const struct of_device_id ls1x_dwmac_syscon_match[] = {
+	{
+		.compatible = "loongson,ls1b-dwmac-syscon",
+		.data = &ls1b_dwmac_syscon,
+	},
+	{
+		.compatible = "loongson,ls1c-dwmac-syscon",
+		.data = &ls1c_dwmac_syscon,
+	},
+	{ }
+};
+
+static int ls1x_dwmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	struct device_node *syscon_np;
+	const struct of_device_id *match;
+	struct regmap *regmap;
+	struct ls1x_dwmac *dwmac;
+	const struct ls1x_dwmac_syscon *syscon;
+	size_t size;
+	int ret;
+
+	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+	if (ret)
+		return ret;
+
+	/* Probe syscon */
+	syscon_np =
+	    of_parse_phandle(pdev->dev.of_node, "loongson,dwmac-syscon", 0);
+	if (!syscon_np) {
+		dev_err(&pdev->dev, "missing loongson,dwmac-syscon property\n");
+		return -ENODEV;
+	}
+
+	match = of_match_node(ls1x_dwmac_syscon_match, syscon_np);
+	if (!match) {
+		dev_err(&pdev->dev, "no matching node found in dtb\n");
+		of_node_put(syscon_np);
+		return -EINVAL;
+	}
+	syscon = (const struct ls1x_dwmac_syscon *)match->data;
+
+	regmap = syscon_node_to_regmap(syscon_np);
+	of_node_put(syscon_np);
+	if (IS_ERR(regmap)) {
+		ret = PTR_ERR(regmap);
+		dev_err(&pdev->dev, "Unable to map syscon: %d\n", ret);
+		return ret;
+	}
+
+	size = syscon->nr_reg_fields * sizeof(struct regmap_field *);
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac) + size, GFP_KERNEL);
+	if (!dwmac)
+		return -ENOMEM;
+
+	plat_dat = stmmac_probe_config_dt(pdev, stmmac_res.mac);
+	if (IS_ERR(plat_dat)) {
+		dev_err(&pdev->dev, "dt configuration failed\n");
+		return PTR_ERR(plat_dat);
+	}
+
+	plat_dat->bsp_priv = dwmac;
+	plat_dat->init = ls1x_dwmac_init;
+	dwmac->dev = &pdev->dev;
+	dwmac->plat_dat = plat_dat;
+	dwmac->syscon = syscon;
+	dwmac->regmap = regmap;
+
+	ret = stmmac_pltfr_probe(pdev, plat_dat, &stmmac_res);
+	if (ret)
+		goto err_remove_config_dt;
+
+	return 0;
+
+err_remove_config_dt:
+	if (pdev->dev.of_node)
+		stmmac_remove_config_dt(pdev, plat_dat);
+
+	return ret;
+}
+
+static const struct of_device_id ls1x_dwmac_match[] = {
+	{ .compatible = "loongson,ls1b-dwmac" },
+	{ .compatible = "loongson,ls1c-dwmac" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, ls1x_dwmac_match);
+
+static struct platform_driver ls1x_dwmac_driver = {
+	.probe = ls1x_dwmac_probe,
+	.remove_new = stmmac_pltfr_remove,
+	.driver = {
+		.name = "loongson1-dwmac",
+		.of_match_table = ls1x_dwmac_match,
+	},
+};
+module_platform_driver(ls1x_dwmac_driver);
+
+MODULE_AUTHOR("Keguang Zhang <keguang.zhang@xxxxxxxxx>");
+MODULE_DESCRIPTION("Loongson1 DWMAC glue layer");
+MODULE_LICENSE("GPL");
-- 
2.39.2