enetc: Make MDIO accessors more generic and export to include/linux/fsl

Within the LS1028A SoC, the register map for the ENETC MDIO controller
is instantiated a few times: for the central (external) MDIO controller,
for the internal bus of each standalone ENETC port, and for the internal
bus of the Felix switch.

Refactoring is needed to support multiple MDIO buses from multiple
drivers. The enetc_hw structure is made an opaque type and a smaller
enetc_mdio_priv is created.

'mdio_base' - MDIO registers base address - is being parameterized, to
be able to work with different MDIO register bases.

The ENETC MDIO bus operations are exported from the fsl-enetc-mdio
kernel object, the same that registers the central MDIO controller (the
dedicated PF). The ENETC main driver has been changed to select it, and
use its exported helpers to further register its private MDIO bus. The
DSA Felix driver will do the same.

Signed-off-by: Claudiu Manoil <claudiu.manoil@nxp.com>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/freescale/enetc/Kconfig

@@ -2,6 +2,7 @@
 config FSL_ENETC
 	tristate "ENETC PF driver"
 	depends on PCI && PCI_MSI && (ARCH_LAYERSCAPE || COMPILE_TEST)
+	select FSL_ENETC_MDIO
 	select PHYLIB
 	help
 	  This driver supports NXP ENETC gigabit ethernet controller PCIe

drivers/net/ethernet/freescale/enetc/Makefile

@@ -3,7 +3,7 @@
 common-objs := enetc.o enetc_cbdr.o enetc_ethtool.o
 
 obj-$(CONFIG_FSL_ENETC) += fsl-enetc.o
-fsl-enetc-y := enetc_pf.o enetc_mdio.o $(common-objs)
+fsl-enetc-y := enetc_pf.o $(common-objs)
 fsl-enetc-$(CONFIG_PCI_IOV) += enetc_msg.o
 fsl-enetc-$(CONFIG_FSL_ENETC_QOS) += enetc_qos.o
 

drivers/net/ethernet/freescale/enetc/enetc_hw.h

@@ -200,6 +200,7 @@ enum enetc_bdr_type {TX, RX};
 #define ENETC_PFPMR		0x1900
 #define ENETC_PFPMR_PMACE	BIT(1)
 #define ENETC_PFPMR_MWLM	BIT(0)
+#define ENETC_EMDIO_BASE	0x1c00
 #define ENETC_PSIUMHFR0(n, err)	(((err) ? 0x1d08 : 0x1d00) + (n) * 0x10)
 #define ENETC_PSIUMHFR1(n)	(0x1d04 + (n) * 0x10)
 #define ENETC_PSIMMHFR0(n, err)	(((err) ? 0x1d00 : 0x1d08) + (n) * 0x10)

drivers/net/ethernet/freescale/enetc/enetc_mdio.c

@@ -1,24 +1,35 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
 /* Copyright 2019 NXP */
 
+#include <linux/fsl/enetc_mdio.h>
 #include <linux/mdio.h>
 #include <linux/of_mdio.h>
 #include <linux/iopoll.h>
 #include <linux/of.h>
 
-#include "enetc_mdio.h"
+#include "enetc_pf.h"
 
-#define	ENETC_MDIO_REG_OFFSET	0x1c00
 #define	ENETC_MDIO_CFG	0x0	/* MDIO configuration and status */
 #define	ENETC_MDIO_CTL	0x4	/* MDIO control */
 #define	ENETC_MDIO_DATA	0x8	/* MDIO data */
 #define	ENETC_MDIO_ADDR	0xc	/* MDIO address */
 
-#define enetc_mdio_rd(hw, off) \
-	enetc_port_rd(hw, ENETC_##off + ENETC_MDIO_REG_OFFSET)
-#define enetc_mdio_wr(hw, off, val) \
-	enetc_port_wr(hw, ENETC_##off + ENETC_MDIO_REG_OFFSET, val)
-#define enetc_mdio_rd_reg(off)	enetc_mdio_rd(hw, off)
+static inline u32 _enetc_mdio_rd(struct enetc_mdio_priv *mdio_priv, int off)
+{
+	return enetc_port_rd(mdio_priv->hw, mdio_priv->mdio_base + off);
+}
+
+static inline void _enetc_mdio_wr(struct enetc_mdio_priv *mdio_priv, int off,
+				  u32 val)
+{
+	enetc_port_wr(mdio_priv->hw, mdio_priv->mdio_base + off, val);
+}
+
+#define enetc_mdio_rd(mdio_priv, off) \
+	_enetc_mdio_rd(mdio_priv, ENETC_##off)
+#define enetc_mdio_wr(mdio_priv, off, val) \
+	_enetc_mdio_wr(mdio_priv, ENETC_##off, val)
+#define enetc_mdio_rd_reg(off)	enetc_mdio_rd(mdio_priv, off)
 
 #define ENETC_MDC_DIV		258
 
@@ -35,7 +46,7 @@
 #define MDIO_DATA(x)		((x) & 0xffff)
 
 #define TIMEOUT	1000
-static int enetc_mdio_wait_complete(struct enetc_hw *hw)
+static int enetc_mdio_wait_complete(struct enetc_mdio_priv *mdio_priv)
 {
 	u32 val;
 
@@ -46,7 +57,6 @@ static int enetc_mdio_wait_complete(struct enetc_hw *hw)
 int enetc_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 value)
 {
 	struct enetc_mdio_priv *mdio_priv = bus->priv;
-	struct enetc_hw *hw = mdio_priv->hw;
 	u32 mdio_ctl, mdio_cfg;
 	u16 dev_addr;
 	int ret;
@@ -61,39 +71,39 @@ int enetc_mdio_write(struct mii_bus *bus, int phy_id, int regnum, u16 value)
 		mdio_cfg &= ~MDIO_CFG_ENC45;
 	}
 
-	enetc_mdio_wr(hw, MDIO_CFG, mdio_cfg);
+	enetc_mdio_wr(mdio_priv, MDIO_CFG, mdio_cfg);
 
-	ret = enetc_mdio_wait_complete(hw);
+	ret = enetc_mdio_wait_complete(mdio_priv);
 	if (ret)
 		return ret;
 
 	/* set port and dev addr */
 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
-	enetc_mdio_wr(hw, MDIO_CTL, mdio_ctl);
+	enetc_mdio_wr(mdio_priv, MDIO_CTL, mdio_ctl);
 
 	/* set the register address */
 	if (regnum & MII_ADDR_C45) {
-		enetc_mdio_wr(hw, MDIO_ADDR, regnum & 0xffff);
+		enetc_mdio_wr(mdio_priv, MDIO_ADDR, regnum & 0xffff);
 
-		ret = enetc_mdio_wait_complete(hw);
+		ret = enetc_mdio_wait_complete(mdio_priv);
 		if (ret)
 			return ret;
 	}
 
 	/* write the value */
-	enetc_mdio_wr(hw, MDIO_DATA, MDIO_DATA(value));
+	enetc_mdio_wr(mdio_priv, MDIO_DATA, MDIO_DATA(value));
 
-	ret = enetc_mdio_wait_complete(hw);
+	ret = enetc_mdio_wait_complete(mdio_priv);
 	if (ret)
 		return ret;
 
 	return 0;
 }
+EXPORT_SYMBOL_GPL(enetc_mdio_write);
 
 int enetc_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 {
 	struct enetc_mdio_priv *mdio_priv = bus->priv;
-	struct enetc_hw *hw = mdio_priv->hw;
 	u32 mdio_ctl, mdio_cfg;
 	u16 dev_addr, value;
 	int ret;
@@ -107,86 +117,56 @@ int enetc_mdio_read(struct mii_bus *bus, int phy_id, int regnum)
 		mdio_cfg &= ~MDIO_CFG_ENC45;
 	}
 
-	enetc_mdio_wr(hw, MDIO_CFG, mdio_cfg);
+	enetc_mdio_wr(mdio_priv, MDIO_CFG, mdio_cfg);
 
-	ret = enetc_mdio_wait_complete(hw);
+	ret = enetc_mdio_wait_complete(mdio_priv);
 	if (ret)
 		return ret;
 
 	/* set port and device addr */
 	mdio_ctl = MDIO_CTL_PORT_ADDR(phy_id) | MDIO_CTL_DEV_ADDR(dev_addr);
-	enetc_mdio_wr(hw, MDIO_CTL, mdio_ctl);
+	enetc_mdio_wr(mdio_priv, MDIO_CTL, mdio_ctl);
 
 	/* set the register address */
 	if (regnum & MII_ADDR_C45) {
-		enetc_mdio_wr(hw, MDIO_ADDR, regnum & 0xffff);
+		enetc_mdio_wr(mdio_priv, MDIO_ADDR, regnum & 0xffff);
 
-		ret = enetc_mdio_wait_complete(hw);
+		ret = enetc_mdio_wait_complete(mdio_priv);
 		if (ret)
 			return ret;
 	}
 
 	/* initiate the read */
-	enetc_mdio_wr(hw, MDIO_CTL, mdio_ctl | MDIO_CTL_READ);
+	enetc_mdio_wr(mdio_priv, MDIO_CTL, mdio_ctl | MDIO_CTL_READ);
 
-	ret = enetc_mdio_wait_complete(hw);
+	ret = enetc_mdio_wait_complete(mdio_priv);
 	if (ret)
 		return ret;
 
 	/* return all Fs if nothing was there */
-	if (enetc_mdio_rd(hw, MDIO_CFG) & MDIO_CFG_RD_ER) {
+	if (enetc_mdio_rd(mdio_priv, MDIO_CFG) & MDIO_CFG_RD_ER) {
 		dev_dbg(&bus->dev,
 			"Error while reading PHY%d reg at %d.%hhu\n",
 			phy_id, dev_addr, regnum);
 		return 0xffff;
 	}
 
-	value = enetc_mdio_rd(hw, MDIO_DATA) & 0xffff;
+	value = enetc_mdio_rd(mdio_priv, MDIO_DATA) & 0xffff;
 
 	return value;
 }
+EXPORT_SYMBOL_GPL(enetc_mdio_read);
 
-int enetc_mdio_probe(struct enetc_pf *pf)
+struct enetc_hw *enetc_hw_alloc(struct device *dev, void __iomem *port_regs)
 {
-	struct device *dev = &pf->si->pdev->dev;
-	struct enetc_mdio_priv *mdio_priv;
-	struct device_node *np;
-	struct mii_bus *bus;
-	int err;
-
-	bus = devm_mdiobus_alloc_size(dev, sizeof(*mdio_priv));
-	if (!bus)
-		return -ENOMEM;
-
-	bus->name = "Freescale ENETC MDIO Bus";
-	bus->read = enetc_mdio_read;
-	bus->write = enetc_mdio_write;
-	bus->parent = dev;
-	mdio_priv = bus->priv;
-	mdio_priv->hw = &pf->si->hw;
-	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
-
-	np = of_get_child_by_name(dev->of_node, "mdio");
-	if (!np) {
-		dev_err(dev, "MDIO node missing\n");
-		return -EINVAL;
-	}
-
-	err = of_mdiobus_register(bus, np);
-	if (err) {
-		of_node_put(np);
-		dev_err(dev, "cannot register MDIO bus\n");
-		return err;
-	}
+	struct enetc_hw *hw;
 
-	of_node_put(np);
-	pf->mdio = bus;
+	hw = devm_kzalloc(dev, sizeof(*hw), GFP_KERNEL);
+	if (!hw)
+		return ERR_PTR(-ENOMEM);
 
-	return 0;
-}
+	hw->port = port_regs;
 
-void enetc_mdio_remove(struct enetc_pf *pf)
-{
-	if (pf->mdio)
-		mdiobus_unregister(pf->mdio);
+	return hw;
 }
+EXPORT_SYMBOL_GPL(enetc_hw_alloc);

drivers/net/ethernet/freescale/enetc/enetc_pci_mdio.c

@@ -1,7 +1,8 @@
 // SPDX-License-Identifier: (GPL-2.0+ OR BSD-3-Clause)
 /* Copyright 2019 NXP */
+#include <linux/fsl/enetc_mdio.h>
 #include <linux/of_mdio.h>
-#include "enetc_mdio.h"
+#include "enetc_pf.h"
 
 #define ENETC_MDIO_DEV_ID	0xee01
 #define ENETC_MDIO_DEV_NAME	"FSL PCIe IE Central MDIO"
@@ -13,31 +14,44 @@ static int enetc_pci_mdio_probe(struct pci_dev *pdev,
 {
 	struct enetc_mdio_priv *mdio_priv;
 	struct device *dev = &pdev->dev;
+	void __iomem *port_regs;
 	struct enetc_hw *hw;
 	struct mii_bus *bus;
 	int err;
 
-	hw = devm_kzalloc(dev, sizeof(*hw), GFP_KERNEL);
-	if (!hw)
-		return -ENOMEM;
+	port_regs = pci_iomap(pdev, 0, 0);
+	if (!port_regs) {
+		dev_err(dev, "iomap failed\n");
+		err = -ENXIO;
+		goto err_ioremap;
+	}
+
+	hw = enetc_hw_alloc(dev, port_regs);
+	if (IS_ERR(enetc_hw_alloc)) {
+		err = PTR_ERR(hw);
+		goto err_hw_alloc;
+	}
 
 	bus = devm_mdiobus_alloc_size(dev, sizeof(*mdio_priv));
-	if (!bus)
-		return -ENOMEM;
+	if (!bus) {
+		err = -ENOMEM;
+		goto err_mdiobus_alloc;
+	}
 
 	bus->name = ENETC_MDIO_BUS_NAME;
 	bus->read = enetc_mdio_read;
 	bus->write = enetc_mdio_write;
 	bus->parent = dev;
 	mdio_priv = bus->priv;
 	mdio_priv->hw = hw;
+	mdio_priv->mdio_base = ENETC_EMDIO_BASE;
 	snprintf(bus->id, MII_BUS_ID_SIZE, "%s", dev_name(dev));
 
 	pcie_flr(pdev);
 	err = pci_enable_device_mem(pdev);
 	if (err) {
 		dev_err(dev, "device enable failed\n");
-		return err;
+		goto err_pci_enable;
 	}
 
 	err = pci_request_region(pdev, 0, KBUILD_MODNAME);
@@ -46,13 +60,6 @@ static int enetc_pci_mdio_probe(struct pci_dev *pdev,
 		goto err_pci_mem_reg;
 	}
 
-	hw->port = pci_iomap(pdev, 0, 0);
-	if (!hw->port) {
-		err = -ENXIO;
-		dev_err(dev, "iomap failed\n");
-		goto err_ioremap;
-	}
-
 	err = of_mdiobus_register(bus, dev->of_node);
 	if (err)
 		goto err_mdiobus_reg;
@@ -62,12 +69,14 @@ static int enetc_pci_mdio_probe(struct pci_dev *pdev,
 	return 0;
 
 err_mdiobus_reg:
-	iounmap(mdio_priv->hw->port);
-err_ioremap:
 	pci_release_mem_regions(pdev);
 err_pci_mem_reg:
 	pci_disable_device(pdev);
-
+err_pci_enable:
+err_mdiobus_alloc:
+	iounmap(port_regs);
+err_hw_alloc:
+err_ioremap:
 	return err;
 }