stmmac: add dwmac glue for NXP 18xx/43xx family

Add support for Ethernet on NXP LPC18xx and LPC43xx using the
dwmac driver. This glue is required to setup phy interface
mode, MII or RMII, on the SoC.
Signed-off-by: Joachim Eastwood <manabian@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/stmicro/stmmac/Makefile

@@ -6,7 +6,8 @@ stmmac-objs:= stmmac_main.o stmmac_ethtool.o stmmac_mdio.o ring_mode.o	\
 
 obj-$(CONFIG_STMMAC_PLATFORM) += stmmac-platform.o
 stmmac-platform-objs:= stmmac_platform.o dwmac-meson.o dwmac-sunxi.o	\
-		       dwmac-sti.o dwmac-socfpga.o dwmac-rk.o
+		       dwmac-sti.o dwmac-socfpga.o dwmac-rk.o		\
+		       dwmac-lpc18xx.o
 
 obj-$(CONFIG_STMMAC_PCI) += stmmac-pci.o
 stmmac-pci-objs:= stmmac_pci.o

drivers/net/ethernet/stmicro/stmmac/dwmac-lpc18xx.c

+/*
+ * DWMAC glue for NXP LPC18xx/LPC43xx Ethernet
+ *
+ * Copyright (C) 2015 Joachim Eastwood <manabian@gmail.com>
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/mfd/syscon.h>
+#include <linux/of.h>
+#include <linux/of_net.h>
+#include <linux/phy.h>
+#include <linux/regmap.h>
+#include <linux/stmmac.h>
+
+/* Register defines for CREG syscon */
+#define LPC18XX_CREG_CREG6			0x12c
+# define LPC18XX_CREG_CREG6_ETHMODE_MASK	0x7
+# define LPC18XX_CREG_CREG6_ETHMODE_MII		0x0
+# define LPC18XX_CREG_CREG6_ETHMODE_RMII	0x4
+
+struct lpc18xx_dwmac_priv_data {
+	struct regmap *reg;
+	int interface;
+};
+
+static void *lpc18xx_dwmac_setup(struct platform_device *pdev)
+{
+	struct lpc18xx_dwmac_priv_data *dwmac;
+
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+	if (!dwmac)
+		return ERR_PTR(-ENOMEM);
+
+	dwmac->interface = of_get_phy_mode(pdev->dev.of_node);
+	if (dwmac->interface < 0)
+		return ERR_PTR(dwmac->interface);
+
+	dwmac->reg = syscon_regmap_lookup_by_compatible("nxp,lpc1850-creg");
+	if (IS_ERR(dwmac->reg)) {
+		dev_err(&pdev->dev, "Syscon lookup failed\n");
+		return dwmac->reg;
+	}
+
+	return dwmac;
+}
+
+static int lpc18xx_dwmac_init(struct platform_device *pdev, void *priv)
+{
+	struct lpc18xx_dwmac_priv_data *dwmac = priv;
+	u8 ethmode;
+
+	if (dwmac->interface == PHY_INTERFACE_MODE_MII) {
+		ethmode = LPC18XX_CREG_CREG6_ETHMODE_MII;
+	} else if (dwmac->interface == PHY_INTERFACE_MODE_RMII) {
+		ethmode = LPC18XX_CREG_CREG6_ETHMODE_RMII;
+	} else {
+		dev_err(&pdev->dev, "Only MII and RMII mode supported\n");
+		return -EINVAL;
+	}
+
+	regmap_update_bits(dwmac->reg, LPC18XX_CREG_CREG6,
+			   LPC18XX_CREG_CREG6_ETHMODE_MASK, ethmode);
+
+	return 0;
+}
+
+const struct stmmac_of_data lpc18xx_dwmac_data = {
+	.has_gmac = 1,
+	.setup = lpc18xx_dwmac_setup,
+	.init = lpc18xx_dwmac_init,
+};

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.c

@@ -37,6 +37,7 @@ static const struct of_device_id stmmac_dt_ids[] = {
 	{ .compatible = "rockchip,rk3288-gmac", .data = &rk3288_gmac_data},
 	{ .compatible = "amlogic,meson6-dwmac", .data = &meson6_dwmac_data},
 	{ .compatible = "allwinner,sun7i-a20-gmac", .data = &sun7i_gmac_data},
+	{ .compatible = "nxp,lpc1850-dwmac", .data = &lpc18xx_dwmac_data},
 	{ .compatible = "st,stih415-dwmac", .data = &stih4xx_dwmac_data},
 	{ .compatible = "st,stih416-dwmac", .data = &stih4xx_dwmac_data},
 	{ .compatible = "st,stid127-dwmac", .data = &stid127_dwmac_data},

drivers/net/ethernet/stmicro/stmmac/stmmac_platform.h

@@ -19,6 +19,7 @@
 #ifndef __STMMAC_PLATFORM_H__
 #define __STMMAC_PLATFORM_H__
 
+extern const struct stmmac_of_data lpc18xx_dwmac_data;
 extern const struct stmmac_of_data meson6_dwmac_data;
 extern const struct stmmac_of_data sun7i_gmac_data;
 extern const struct stmmac_of_data stih4xx_dwmac_data;