[PATCH 1/4] net: ethernet: dwmac: add Ethernet glue logic for stm32 chip

[Alexandre TORGUE <alexandre.torgue@gmail.com>]

stm324xx family chips support Synopsys MAC 3.510 IP.
This patch adds settings for logical glue logic:
-clocks
-mode selection MII or RMII.

Signed-off-by: Alexandre TORGUE <alexandre.torgue@gmail.com>

diff --git a/drivers/net/ethernet/stmicro/stmmac/Kconfig b/drivers/net/ethernet/stmicro/stmmac/Kconfig
index cec147d..a94dd15 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Kconfig
+++ b/drivers/net/ethernet/stmicro/stmmac/Kconfig
@@ -114,6 +114,18 @@ config DWMAC_SUNXI
 	  This selects Allwinner SoC glue layer support for the
 	  stmmac device driver. This driver is used for A20/A31
 	  GMAC ethernet controller.
+
+config DWMAC_STM32
+	tristate "STM32 DWMAC support"
+	default ARCH_STM32
+	depends on OF
+	select MFD_SYSCON
+	---help---
+	  Support for ethernet controller on STM32 SOCs.
+
+	  This selects STM32 SoC glue layer support for the stmmac
+	  device driver. This driver is used on for the STM32 series
+	  SOCs GMAC ethernet controller.
 endif
 
 config STMMAC_PCI
diff --git a/drivers/net/ethernet/stmicro/stmmac/Makefile b/drivers/net/ethernet/stmicro/stmmac/Makefile
index b390161..9fb2061 100644
--- a/drivers/net/ethernet/stmicro/stmmac/Makefile
+++ b/drivers/net/ethernet/stmicro/stmmac/Makefile
@@ -14,6 +14,7 @@ obj-$(CONFIG_DWMAC_SOCFPGA)	+= dwmac-socfpga.o
 obj-$(CONFIG_DWMAC_STI)		+= dwmac-sti.o
 obj-$(CONFIG_DWMAC_SUNXI)	+= dwmac-sunxi.o
 obj-$(CONFIG_DWMAC_GENERIC)	+= dwmac-generic.o
+obj-$(CONFIG_DWMAC_STM32)	+= dwmac-stm32.o
 stmmac-platform-objs:= stmmac_platform.o
 
 obj-$(CONFIG_STMMAC_PCI) += stmmac-pci.o
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
new file mode 100644
index 0000000..56ccc20
--- /dev/null
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac-stm32.c
@@ -0,0 +1,177 @@
+/*
+ * dwmac-stm32.c - DWMAC Specific Glue layer for STM32 MCU
+ *
+ * Copyright (C) Alexandre Torgue 2015
+ * Author:  Alexandre Torgue <alexandre.torgue@gmail.com>
+ * License terms:  GNU General Public License (GPL), version 2
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/slab.h>
+#include <linux/platform_device.h>
+#include <linux/stmmac.h>
+#include <linux/phy.h>
+#include <linux/mfd/syscon.h>
+#include <linux/module.h>
+#include <linux/regmap.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+#include <linux/of_net.h>
+
+#include "stmmac_platform.h"
+
+#define MII_PHY_SEL_MASK	BIT(23)
+
+struct stm32_dwmac {
+	int interface;		/* MII interface */
+	struct clk *clk_tx;
+	struct clk *clk_rx;
+	u32 mode_reg;		/* MAC glue-logic mode register */
+	struct device *dev;
+	struct regmap *regmap;
+	u32 speed;
+};
+
+static int stm32_dwmac_init(struct platform_device *pdev, void *priv)
+{
+	struct stm32_dwmac *dwmac = priv;
+	struct regmap *regmap = dwmac->regmap;
+	int ret, iface = dwmac->interface;
+	u32 reg = dwmac->mode_reg;
+	u32 val;
+
+	if (dwmac->clk_tx)
+		ret = clk_prepare_enable(dwmac->clk_tx);
+		if (ret)
+			goto out;
+
+	if (dwmac->clk_rx)
+		ret = clk_prepare_enable(dwmac->clk_rx);
+		if (ret)
+			goto out_disable_clk_tx;
+
+	val = (iface == PHY_INTERFACE_MODE_MII) ? 0 : 1;
+	ret = regmap_update_bits(regmap, reg, MII_PHY_SEL_MASK, val);
+	if (ret)
+		goto out_disable_clk_tx_rx;
+
+	return 0;
+
+out_disable_clk_tx_rx:
+	clk_disable_unprepare(dwmac->clk_rx);
+out_disable_clk_tx:
+	clk_disable_unprepare(dwmac->clk_tx);
+out:
+	return ret;
+}
+
+static void stm32_dwmac_exit(struct platform_device *pdev, void *priv)
+{
+	struct stm32_dwmac *dwmac = priv;
+
+	if (dwmac->clk_tx)
+		clk_disable_unprepare(dwmac->clk_tx);
+	if (dwmac->clk_rx)
+		clk_disable_unprepare(dwmac->clk_rx);
+}
+
+static int stm32_dwmac_parse_data(struct stm32_dwmac *dwmac,
+				  struct platform_device *pdev)
+{
+	struct device *dev = &pdev->dev;
+	struct device_node *np = dev->of_node;
+	struct regmap *regmap;
+	int err;
+
+	if (!np)
+		return -EINVAL;
+
+	/*  Get TX/RX clocks */
+	dwmac->clk_tx = devm_clk_get(dev, "tx-clk");
+	if (IS_ERR(dwmac->clk_tx)) {
+		dev_warn(dev, "No tx clock provided...\n");
+		dwmac->clk_tx = NULL;
+	}
+	dwmac->clk_rx = devm_clk_get(dev, "rx-clk");
+	if (IS_ERR(dwmac->clk_rx)) {
+		dev_warn(dev, "No rx clock provided...\n");
+		dwmac->clk_rx = NULL;
+	}
+
+	/* Get mode register */
+	regmap = syscon_regmap_lookup_by_phandle(np, "st,syscon");
+	if (IS_ERR(regmap))
+		return PTR_ERR(regmap);
+
+	err = of_property_read_u32_index(np, "st,syscon", 1, &dwmac->mode_reg);
+	if (err) {
+		dev_err(dev, "Can't get sysconfig mode offset (%d)\n", err);
+		return err;
+	}
+
+	dwmac->dev = dev;
+	dwmac->interface = of_get_phy_mode(np);
+	dwmac->regmap = regmap;
+
+	return 0;
+}
+
+static int stm32_dwmac_probe(struct platform_device *pdev)
+{
+	struct plat_stmmacenet_data *plat_dat;
+	struct stmmac_resources stmmac_res;
+	struct stm32_dwmac *dwmac;
+	int ret;
+
+	ret = stmmac_get_platform_resources(pdev, &stmmac_res);
+	if (ret)
+		return ret;
+
+	plat_dat = stmmac_probe_config_dt(pdev, &stmmac_res.mac);
+	if (IS_ERR(plat_dat))
+		return PTR_ERR(plat_dat);
+
+	dwmac = devm_kzalloc(&pdev->dev, sizeof(*dwmac), GFP_KERNEL);
+	if (!dwmac)
+		return -ENOMEM;
+
+	ret = stm32_dwmac_parse_data(dwmac, pdev);
+	if (ret) {
+		dev_err(&pdev->dev, "Unable to parse OF data\n");
+		return ret;
+	}
+
+	plat_dat->bsp_priv = dwmac;
+	plat_dat->init = stm32_dwmac_init;
+	plat_dat->exit = stm32_dwmac_exit;
+
+	ret = stm32_dwmac_init(pdev, plat_dat->bsp_priv);
+	if (ret)
+		return ret;
+
+	return stmmac_dvr_probe(&pdev->dev, plat_dat, &stmmac_res);
+}
+
+static const struct of_device_id stm32_dwmac_match[] = {
+	{ .compatible = "st,stm32-dwmac"},
+	{ }
+};
+MODULE_DEVICE_TABLE(of, stm32_dwmac_match);
+
+static struct platform_driver stm32_dwmac_driver = {
+	.probe  = stm32_dwmac_probe,
+	.remove = stmmac_pltfr_remove,
+	.driver = {
+		.name           = "stm32-dwmac",
+		.pm		= &stmmac_pltfr_pm_ops,
+		.of_match_table = stm32_dwmac_match,
+	},
+};
+module_platform_driver(stm32_dwmac_driver);
+
+MODULE_AUTHOR("Alexandre Torgue <alexandre.torgue@gmail.com>");
+MODULE_DESCRIPTION("STMicroelectronics MCU DWMAC Specific Glue layer");
+MODULE_LICENSE("GPL");
+
-- 
1.9.1