net: txgbe: Implement phylink pcs

Register MDIO bus for PCS layer to use Synopsys designware XPCS, support
10GBASE-R interface to the controller.

Signed-off-by: Jiawen Wu <jiawenwu@trustnetic.com>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Reviewed-by: Maciej Fijalkowski <maciej.fijalkowski@intel.com>
Signed-off-by: Paolo Abeni <pabeni@redhat.com>

drivers/net/ethernet/wangxun/Kconfig

@@ -49,6 +49,7 @@ config TXGBE
 	select SFP
 	select GPIOLIB
 	select GPIOLIB_IRQCHIP
+	select PCS_XPCS
 	select LIBWX
 	help
 	  This driver supports Wangxun(R) 10GbE PCI Express family of

drivers/net/ethernet/wangxun/txgbe/txgbe_phy.c

@@ -10,6 +10,7 @@
 #include <linux/pci.h>
 #include <linux/platform_device.h>
 #include <linux/regmap.h>
+#include <linux/pcs/pcs-xpcs.h>
 
 #include "../libwx/wx_type.h"
 #include "../libwx/wx_hw.h"
@@ -77,6 +78,81 @@ static int txgbe_swnodes_register(struct txgbe *txgbe)
 	return software_node_register_node_group(nodes->group);
 }
 
+static int txgbe_pcs_read(struct mii_bus *bus, int addr, int devnum, int regnum)
+{
+	struct wx *wx  = bus->priv;
+	u32 offset, val;
+
+	if (addr)
+		return -EOPNOTSUPP;
+
+	offset = devnum << 16 | regnum;
+
+	/* Set the LAN port indicator to IDA_ADDR */
+	wr32(wx, TXGBE_XPCS_IDA_ADDR, offset);
+
+	/* Read the data from IDA_DATA register */
+	val = rd32(wx, TXGBE_XPCS_IDA_DATA);
+
+	return (u16)val;
+}
+
+static int txgbe_pcs_write(struct mii_bus *bus, int addr, int devnum, int regnum, u16 val)
+{
+	struct wx *wx = bus->priv;
+	u32 offset;
+
+	if (addr)
+		return -EOPNOTSUPP;
+
+	offset = devnum << 16 | regnum;
+
+	/* Set the LAN port indicator to IDA_ADDR */
+	wr32(wx, TXGBE_XPCS_IDA_ADDR, offset);
+
+	/* Write the data to IDA_DATA register */
+	wr32(wx, TXGBE_XPCS_IDA_DATA, val);
+
+	return 0;
+}
+
+static int txgbe_mdio_pcs_init(struct txgbe *txgbe)
+{
+	struct mii_bus *mii_bus;
+	struct dw_xpcs *xpcs;
+	struct pci_dev *pdev;
+	struct wx *wx;
+	int ret = 0;
+
+	wx = txgbe->wx;
+	pdev = wx->pdev;
+
+	mii_bus = devm_mdiobus_alloc(&pdev->dev);
+	if (!mii_bus)
+		return -ENOMEM;
+
+	mii_bus->name = "txgbe_pcs_mdio_bus";
+	mii_bus->read_c45 = &txgbe_pcs_read;
+	mii_bus->write_c45 = &txgbe_pcs_write;
+	mii_bus->parent = &pdev->dev;
+	mii_bus->phy_mask = ~0;
+	mii_bus->priv = wx;
+	snprintf(mii_bus->id, MII_BUS_ID_SIZE, "txgbe_pcs-%x",
+		 (pdev->bus->number << 8) | pdev->devfn);
+
+	ret = devm_mdiobus_register(&pdev->dev, mii_bus);
+	if (ret)
+		return ret;
+
+	xpcs = xpcs_create_mdiodev(mii_bus, 0, PHY_INTERFACE_MODE_10GBASER);
+	if (IS_ERR(xpcs))
+		return PTR_ERR(xpcs);
+
+	txgbe->xpcs = xpcs;
+
+	return 0;
+}
+
 static int txgbe_gpio_get(struct gpio_chip *chip, unsigned int offset)
 {
 	struct wx *wx = gpiochip_get_data(chip);
@@ -432,16 +508,22 @@ int txgbe_init_phy(struct txgbe *txgbe)
 		return ret;
 	}
 
+	ret = txgbe_mdio_pcs_init(txgbe);
+	if (ret) {
+		wx_err(txgbe->wx, "failed to init mdio pcs: %d\n", ret);
+		goto err_unregister_swnode;
+	}
+
 	ret = txgbe_gpio_init(txgbe);
 	if (ret) {
 		wx_err(txgbe->wx, "failed to init gpio\n");
-		goto err_unregister_swnode;
+		goto err_destroy_xpcs;
 	}
 
 	ret = txgbe_clock_register(txgbe);
 	if (ret) {
 		wx_err(txgbe->wx, "failed to register clock: %d\n", ret);
-		goto err_unregister_swnode;
+		goto err_destroy_xpcs;
 	}
 
 	ret = txgbe_i2c_register(txgbe);
@@ -463,6 +545,8 @@ int txgbe_init_phy(struct txgbe *txgbe)
 err_unregister_clk:
 	clkdev_drop(txgbe->clock);
 	clk_unregister(txgbe->clk);
+err_destroy_xpcs:
+	xpcs_destroy(txgbe->xpcs);
 err_unregister_swnode:
 	software_node_unregister_node_group(txgbe->nodes.group);
 
@@ -475,5 +559,6 @@ void txgbe_remove_phy(struct txgbe *txgbe)
 	platform_device_unregister(txgbe->i2c_dev);
 	clkdev_drop(txgbe->clock);
 	clk_unregister(txgbe->clk);
+	xpcs_destroy(txgbe->xpcs);
 	software_node_unregister_node_group(txgbe->nodes.group);
 }

drivers/net/ethernet/wangxun/txgbe/txgbe_type.h

@@ -80,6 +80,10 @@
 /* I2C registers */
 #define TXGBE_I2C_BASE                          0x14900
 
+/************************************** ETH PHY ******************************/
+#define TXGBE_XPCS_IDA_ADDR                     0x13000
+#define TXGBE_XPCS_IDA_DATA                     0x13004
+
 /* Part Number String Length */
 #define TXGBE_PBANUM_LENGTH                     32
 
@@ -172,6 +176,7 @@ struct txgbe_nodes {
 struct txgbe {
 	struct wx *wx;
 	struct txgbe_nodes nodes;
+	struct dw_xpcs *xpcs;
 	struct platform_device *sfp_dev;
 	struct platform_device *i2c_dev;
 	struct clk_lookup *clock;