drivers/net/ethernet/freescale/fsl_pq_mdio.c - kernel/quantenna - Git at Google

 /*
  * Freescale PowerQUICC Ethernet Driver -- MIIM bus implementation
  * Provides Bus interface for MIIM regs
  *
  * Author: Andy Fleming <afleming@freescale.com>
  * Modifier: Sandeep Gopalpet <sandeep.kumar@freescale.com>
  *
  * Copyright 2002-2004, 2008-2009 Freescale Semiconductor, Inc.
  *
  * Based on gianfar_mii.c and ucc_geth_mii.c (Li Yang, Kim Phillips)
  *
  * This program is free software; you can redistribute  it and/or modify it
  * under  the terms of  the GNU General  Public License as published by the
  * Free Software Foundation;  either version 2 of the  License, or (at your
  * option) any later version.
  *
  */

 #include <linux/kernel.h>
 #include <linux/string.h>
 #include <linux/errno.h>
 #include <linux/slab.h>
 #include <linux/delay.h>
 #include <linux/module.h>
 #include <linux/mii.h>
 #include <linux/of_address.h>
 #include <linux/of_mdio.h>
 #include <linux/of_device.h>

 #include <asm/io.h>
 #if IS_ENABLED(CONFIG_UCC_GETH)
 #include <soc/fsl/qe/ucc.h>
 #endif

 #include "gianfar.h"

 #define MIIMIND_BUSY		0x00000001
 #define MIIMIND_NOTVALID	0x00000004
 #define MIIMCFG_INIT_VALUE	0x00000007
 #define MIIMCFG_RESET		0x80000000

 #define MII_READ_COMMAND	0x00000001

 struct fsl_pq_mii {
 	u32 miimcfg;	/* MII management configuration reg */
 	u32 miimcom;	/* MII management command reg */
 	u32 miimadd;	/* MII management address reg */
 	u32 miimcon;	/* MII management control reg */
 	u32 miimstat;	/* MII management status reg */
 	u32 miimind;	/* MII management indication reg */
 };

 struct fsl_pq_mdio {
 	u8 res1[16];
 	u32 ieventm;	/* MDIO Interrupt event register (for etsec2)*/
 	u32 imaskm;	/* MDIO Interrupt mask register (for etsec2)*/
 	u8 res2[4];
 	u32 emapm;	/* MDIO Event mapping register (for etsec2)*/
 	u8 res3[1280];
 	struct fsl_pq_mii mii;
 	u8 res4[28];
 	u32 utbipar;	/* TBI phy address reg (only on UCC) */
 	u8 res5[2728];
 } __packed;

 /* Number of microseconds to wait for an MII register to respond */
 #define MII_TIMEOUT	1000

 struct fsl_pq_mdio_priv {
 	void __iomem *map;
 	struct fsl_pq_mii __iomem *regs;
 };

 /*
  * Per-device-type data.  Each type of device tree node that we support gets
  * one of these.
  *
  * @mii_offset: the offset of the MII registers within the memory map of the
  * node.  Some nodes define only the MII registers, and some define the whole
  * MAC (which includes the MII registers).
  *
  * @get_tbipa: determines the address of the TBIPA register
  *
  * @ucc_configure: a special function for extra QE configuration
  */
 struct fsl_pq_mdio_data {
 	unsigned int mii_offset;	/* offset of the MII registers */
 	uint32_t __iomem * (*get_tbipa)(void __iomem *p);
 	void (*ucc_configure)(phys_addr_t start, phys_addr_t end);
 };

 /*
  * Write value to the PHY at mii_id at register regnum, on the bus attached
  * to the local interface, which may be different from the generic mdio bus
  * (tied to a single interface), waiting until the write is done before
  * returning. This is helpful in programming interfaces like the TBI which
  * control interfaces like onchip SERDES and are always tied to the local
  * mdio pins, which may not be the same as system mdio bus, used for
  * controlling the external PHYs, for example.
  */
 static int fsl_pq_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
 		u16 value)
 {
 	struct fsl_pq_mdio_priv *priv = bus->priv;
 	struct fsl_pq_mii __iomem *regs = priv->regs;
 	unsigned int timeout;

 	/* Set the PHY address and the register address we want to write */
 	iowrite32be((mii_id << 8) | regnum, &regs->miimadd);

 	/* Write out the value we want */
 	iowrite32be(value, &regs->miimcon);

 	/* Wait for the transaction to finish */
 	timeout = MII_TIMEOUT;
 	while ((ioread32be(&regs->miimind) & MIIMIND_BUSY) && timeout) {
 		cpu_relax();
 		timeout--;
 	}

 	return timeout ? 0 : -ETIMEDOUT;
 }

 /*
  * Read the bus for PHY at addr mii_id, register regnum, and return the value.
  * Clears miimcom first.
  *
  * All PHY operation done on the bus attached to the local interface, which
  * may be different from the generic mdio bus.  This is helpful in programming
  * interfaces like the TBI which, in turn, control interfaces like on-chip
  * SERDES and are always tied to the local mdio pins, which may not be the
  * same as system mdio bus, used for controlling the external PHYs, for eg.
  */
 static int fsl_pq_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
 {
 	struct fsl_pq_mdio_priv *priv = bus->priv;
 	struct fsl_pq_mii __iomem *regs = priv->regs;
 	unsigned int timeout;
 	u16 value;

 	/* Set the PHY address and the register address we want to read */
 	iowrite32be((mii_id << 8) | regnum, &regs->miimadd);

 	/* Clear miimcom, and then initiate a read */
 	iowrite32be(0, &regs->miimcom);
 	iowrite32be(MII_READ_COMMAND, &regs->miimcom);

 	/* Wait for the transaction to finish, normally less than 100us */
 	timeout = MII_TIMEOUT;
 	while ((ioread32be(&regs->miimind) &
 	       (MIIMIND_NOTVALID | MIIMIND_BUSY)) && timeout) {
 		cpu_relax();
 		timeout--;
 	}

 	if (!timeout)
 		return -ETIMEDOUT;

 	/* Grab the value of the register from miimstat */
 	value = ioread32be(&regs->miimstat);

 	dev_dbg(&bus->dev, "read %04x from address %x/%x\n", value, mii_id, regnum);
 	return value;
 }

 /* Reset the MIIM registers, and wait for the bus to free */
 static int fsl_pq_mdio_reset(struct mii_bus *bus)
 {
 	struct fsl_pq_mdio_priv *priv = bus->priv;
 	struct fsl_pq_mii __iomem *regs = priv->regs;
 	unsigned int timeout;

 	mutex_lock(&bus->mdio_lock);

 	/* Reset the management interface */
 	iowrite32be(MIIMCFG_RESET, &regs->miimcfg);

 	/* Setup the MII Mgmt clock speed */
 	iowrite32be(MIIMCFG_INIT_VALUE, &regs->miimcfg);

 	/* Wait until the bus is free */
 	timeout = MII_TIMEOUT;
 	while ((ioread32be(&regs->miimind) & MIIMIND_BUSY) && timeout) {
 		cpu_relax();
 		timeout--;
 	}

 	mutex_unlock(&bus->mdio_lock);

 	if (!timeout) {
 		dev_err(&bus->dev, "timeout waiting for MII bus\n");
 		return -EBUSY;
 	}

 	return 0;
 }

 #if defined(CONFIG_GIANFAR) || defined(CONFIG_GIANFAR_MODULE)
 /*
  * Return the TBIPA address, starting from the address
  * of the mapped GFAR MDIO registers (struct gfar)
  * This is mildly evil, but so is our hardware for doing this.
  * Also, we have to cast back to struct gfar because of
  * definition weirdness done in gianfar.h.
  */
 static uint32_t __iomem *get_gfar_tbipa_from_mdio(void __iomem *p)
 {
 	struct gfar __iomem *enet_regs = p;

 	return &enet_regs->tbipa;
 }

 /*
  * Return the TBIPA address, starting from the address
  * of the mapped GFAR MII registers (gfar_mii_regs[] within struct gfar)
  */
 static uint32_t __iomem *get_gfar_tbipa_from_mii(void __iomem *p)
 {
 	return get_gfar_tbipa_from_mdio(container_of(p, struct gfar, gfar_mii_regs));
 }

 /*
  * Return the TBIPAR address for an eTSEC2 node
  */
 static uint32_t __iomem *get_etsec_tbipa(void __iomem *p)
 {
 	return p;
 }
 #endif

 #if defined(CONFIG_UCC_GETH) || defined(CONFIG_UCC_GETH_MODULE)
 /*
  * Return the TBIPAR address for a QE MDIO node, starting from the address
  * of the mapped MII registers (struct fsl_pq_mii)
  */
 static uint32_t __iomem *get_ucc_tbipa(void __iomem *p)
 {
 	struct fsl_pq_mdio __iomem *mdio = container_of(p, struct fsl_pq_mdio, mii);

 	return &mdio->utbipar;
 }

 /*
  * Find the UCC node that controls the given MDIO node
  *
  * For some reason, the QE MDIO nodes are not children of the UCC devices
  * that control them.  Therefore, we need to scan all UCC nodes looking for
  * the one that encompases the given MDIO node.  We do this by comparing
  * physical addresses.  The 'start' and 'end' addresses of the MDIO node are
  * passed, and the correct UCC node will cover the entire address range.
  *
  * This assumes that there is only one QE MDIO node in the entire device tree.
  */
 static void ucc_configure(phys_addr_t start, phys_addr_t end)
 {
 	static bool found_mii_master;
 	struct device_node *np = NULL;

 	if (found_mii_master)
 		return;

 	for_each_compatible_node(np, NULL, "ucc_geth") {
 		struct resource res;
 		const uint32_t *iprop;
 		uint32_t id;
 		int ret;

 		ret = of_address_to_resource(np, 0, &res);
 		if (ret < 0) {
 			pr_debug("fsl-pq-mdio: no address range in node %s\n",
 				 np->full_name);
 			continue;
 		}

 		/* if our mdio regs fall within this UCC regs range */
 		if ((start < res.start) || (end > res.end))
 			continue;

 		iprop = of_get_property(np, "cell-index", NULL);
 		if (!iprop) {
 			iprop = of_get_property(np, "device-id", NULL);
 			if (!iprop) {
 				pr_debug("fsl-pq-mdio: no UCC ID in node %s\n",
 					 np->full_name);
 				continue;
 			}
 		}

 		id = be32_to_cpup(iprop);

 		/*
 		 * cell-index and device-id for QE nodes are
 		 * numbered from 1, not 0.
 		 */
 		if (ucc_set_qe_mux_mii_mng(id - 1) < 0) {
 			pr_debug("fsl-pq-mdio: invalid UCC ID in node %s\n",
 				 np->full_name);
 			continue;
 		}

 		pr_debug("fsl-pq-mdio: setting node UCC%u to MII master\n", id);
 		found_mii_master = true;
 	}
 }

 #endif

 static const struct of_device_id fsl_pq_mdio_match[] = {
 #if defined(CONFIG_GIANFAR) || defined(CONFIG_GIANFAR_MODULE)
 	{
 		.compatible = "fsl,gianfar-tbi",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = 0,
 			.get_tbipa = get_gfar_tbipa_from_mii,
 		},
 	},
 	{
 		.compatible = "fsl,gianfar-mdio",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = 0,
 			.get_tbipa = get_gfar_tbipa_from_mii,
 		},
 	},
 	{
 		.type = "mdio",
 		.compatible = "gianfar",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = offsetof(struct fsl_pq_mdio, mii),
 			.get_tbipa = get_gfar_tbipa_from_mdio,
 		},
 	},
 	{
 		.compatible = "fsl,etsec2-tbi",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = offsetof(struct fsl_pq_mdio, mii),
 			.get_tbipa = get_etsec_tbipa,
 		},
 	},
 	{
 		.compatible = "fsl,etsec2-mdio",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = offsetof(struct fsl_pq_mdio, mii),
 			.get_tbipa = get_etsec_tbipa,
 		},
 	},
 #endif
 #if defined(CONFIG_UCC_GETH) || defined(CONFIG_UCC_GETH_MODULE)
 	{
 		.compatible = "fsl,ucc-mdio",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = 0,
 			.get_tbipa = get_ucc_tbipa,
 			.ucc_configure = ucc_configure,
 		},
 	},
 	{
 		/* Legacy UCC MDIO node */
 		.type = "mdio",
 		.compatible = "ucc_geth_phy",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = 0,
 			.get_tbipa = get_ucc_tbipa,
 			.ucc_configure = ucc_configure,
 		},
 	},
 #endif
 	/* No Kconfig option for Fman support yet */
 	{
 		.compatible = "fsl,fman-mdio",
 		.data = &(struct fsl_pq_mdio_data) {
 			.mii_offset = 0,
 			/* Fman TBI operations are handled elsewhere */
 		},
 	},

 	{},
 };
 MODULE_DEVICE_TABLE(of, fsl_pq_mdio_match);

 static int fsl_pq_mdio_probe(struct platform_device *pdev)
 {
 	const struct of_device_id *id =
 		of_match_device(fsl_pq_mdio_match, &pdev->dev);
 	const struct fsl_pq_mdio_data *data = id->data;
 	struct device_node *np = pdev->dev.of_node;
 	struct resource res;
 	struct device_node *tbi;
 	struct fsl_pq_mdio_priv *priv;
 	struct mii_bus *new_bus;
 	int err;

 	dev_dbg(&pdev->dev, "found %s compatible node\n", id->compatible);

 	new_bus = mdiobus_alloc_size(sizeof(*priv));
 	if (!new_bus)
 		return -ENOMEM;

 	priv = new_bus->priv;
 	new_bus->name = "Freescale PowerQUICC MII Bus",
 	new_bus->read = &fsl_pq_mdio_read;
 	new_bus->write = &fsl_pq_mdio_write;
 	new_bus->reset = &fsl_pq_mdio_reset;

 	err = of_address_to_resource(np, 0, &res);
 	if (err < 0) {
 		dev_err(&pdev->dev, "could not obtain address information\n");
 		goto error;
 	}

 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s@%llx", np->name,
 		(unsigned long long)res.start);

 	priv->map = of_iomap(np, 0);
 	if (!priv->map) {
 		err = -ENOMEM;
 		goto error;
 	}

 	/*
 	 * Some device tree nodes represent only the MII registers, and
 	 * others represent the MAC and MII registers.  The 'mii_offset' field
 	 * contains the offset of the MII registers inside the mapped register
 	 * space.
 	 */
 	if (data->mii_offset > resource_size(&res)) {
 		dev_err(&pdev->dev, "invalid register map\n");
 		err = -EINVAL;
 		goto error;
 	}
 	priv->regs = priv->map + data->mii_offset;

 	new_bus->parent = &pdev->dev;
 	platform_set_drvdata(pdev, new_bus);

 	if (data->get_tbipa) {
 		for_each_child_of_node(np, tbi) {
 			if (strcmp(tbi->type, "tbi-phy") == 0) {
 				dev_dbg(&pdev->dev, "found TBI PHY node %s\n",
 					strrchr(tbi->full_name, '/') + 1);
 				break;
 			}
 		}

 		if (tbi) {
 			const u32 *prop = of_get_property(tbi, "reg", NULL);
 			uint32_t __iomem *tbipa;

 			if (!prop) {
 				dev_err(&pdev->dev,
 					"missing 'reg' property in node %s\n",
 					tbi->full_name);
 				err = -EBUSY;
 				goto error;
 			}

 			tbipa = data->get_tbipa(priv->map);

 			/*
 			 * Add consistency check to make sure TBI is contained
 			 * within the mapped range (not because we would get a
 			 * segfault, rather to catch bugs in computing TBI
 			 * address). Print error message but continue anyway.
 			 */
 			if ((void *)tbipa > priv->map + resource_size(&res) - 4)
 				dev_err(&pdev->dev, "invalid register map (should be at least 0x%04zx to contain TBI address)\n",
 					((void *)tbipa - priv->map) + 4);

 			iowrite32be(be32_to_cpup(prop), tbipa);
 		}
 	}

 	if (data->ucc_configure)
 		data->ucc_configure(res.start, res.end);

 	err = of_mdiobus_register(new_bus, np);
 	if (err) {
 		dev_err(&pdev->dev, "cannot register %s as MDIO bus\n",
 			new_bus->name);
 		goto error;
 	}

 	return 0;

 error:
 	if (priv->map)
 		iounmap(priv->map);

 	kfree(new_bus);

 	return err;
 }


 static int fsl_pq_mdio_remove(struct platform_device *pdev)
 {
 	struct device *device = &pdev->dev;
 	struct mii_bus *bus = dev_get_drvdata(device);
 	struct fsl_pq_mdio_priv *priv = bus->priv;

 	mdiobus_unregister(bus);

 	iounmap(priv->map);
 	mdiobus_free(bus);

 	return 0;
 }

 static struct platform_driver fsl_pq_mdio_driver = {
 	.driver = {
 		.name = "fsl-pq_mdio",
 		.of_match_table = fsl_pq_mdio_match,
 	},
 	.probe = fsl_pq_mdio_probe,
 	.remove = fsl_pq_mdio_remove,
 };

 module_platform_driver(fsl_pq_mdio_driver);

 MODULE_LICENSE("GPL");
	/*
	* Freescale PowerQUICC Ethernet Driver -- MIIM bus implementation
	* Provides Bus interface for MIIM regs
	*
	* Author: Andy Fleming <afleming@freescale.com>
	* Modifier: Sandeep Gopalpet <sandeep.kumar@freescale.com>
	*
	* Copyright 2002-2004, 2008-2009 Freescale Semiconductor, Inc.
	*
	* Based on gianfar_mii.c and ucc_geth_mii.c (Li Yang, Kim Phillips)
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License as published by the
	* Free Software Foundation; either version 2 of the License, or (at your
	* option) any later version.
	*
	*/

	#include <linux/kernel.h>
	#include <linux/string.h>
	#include <linux/errno.h>
	#include <linux/slab.h>
	#include <linux/delay.h>
	#include <linux/module.h>
	#include <linux/mii.h>
	#include <linux/of_address.h>
	#include <linux/of_mdio.h>
	#include <linux/of_device.h>

	#include <asm/io.h>
	#if IS_ENABLED(CONFIG_UCC_GETH)
	#include <soc/fsl/qe/ucc.h>
	#endif

	#include "gianfar.h"

	#define MIIMIND_BUSY 0x00000001
	#define MIIMIND_NOTVALID 0x00000004
	#define MIIMCFG_INIT_VALUE 0x00000007
	#define MIIMCFG_RESET 0x80000000

	#define MII_READ_COMMAND 0x00000001

	struct fsl_pq_mii {
	u32 miimcfg; /* MII management configuration reg */
	u32 miimcom; /* MII management command reg */
	u32 miimadd; /* MII management address reg */
	u32 miimcon; /* MII management control reg */
	u32 miimstat; /* MII management status reg */
	u32 miimind; /* MII management indication reg */
	};

	struct fsl_pq_mdio {
	u8 res1[16];
	u32 ieventm; /* MDIO Interrupt event register (for etsec2)*/
	u32 imaskm; /* MDIO Interrupt mask register (for etsec2)*/
	u8 res2[4];
	u32 emapm; /* MDIO Event mapping register (for etsec2)*/
	u8 res3[1280];
	struct fsl_pq_mii mii;
	u8 res4[28];
	u32 utbipar; /* TBI phy address reg (only on UCC) */
	u8 res5[2728];
	} __packed;

	/* Number of microseconds to wait for an MII register to respond */
	#define MII_TIMEOUT 1000

	struct fsl_pq_mdio_priv {
	void __iomem *map;
	struct fsl_pq_mii __iomem *regs;
	};

	/*
	* Per-device-type data. Each type of device tree node that we support gets
	* one of these.
	*
	* @mii_offset: the offset of the MII registers within the memory map of the
	* node. Some nodes define only the MII registers, and some define the whole
	* MAC (which includes the MII registers).
	*
	* @get_tbipa: determines the address of the TBIPA register
	*
	* @ucc_configure: a special function for extra QE configuration
	*/
	struct fsl_pq_mdio_data {
	unsigned int mii_offset; /* offset of the MII registers */
	uint32_t __iomem * (get_tbipa)(void __iomem p);
	void (*ucc_configure)(phys_addr_t start, phys_addr_t end);
	};

	/*
	* Write value to the PHY at mii_id at register regnum, on the bus attached
	* to the local interface, which may be different from the generic mdio bus
	* (tied to a single interface), waiting until the write is done before
	* returning. This is helpful in programming interfaces like the TBI which
	* control interfaces like onchip SERDES and are always tied to the local
	* mdio pins, which may not be the same as system mdio bus, used for
	* controlling the external PHYs, for example.
	*/
	static int fsl_pq_mdio_write(struct mii_bus *bus, int mii_id, int regnum,
	u16 value)
	{
	struct fsl_pq_mdio_priv *priv = bus->priv;
	struct fsl_pq_mii __iomem *regs = priv->regs;
	unsigned int timeout;

	/* Set the PHY address and the register address we want to write */
	iowrite32be((mii_id << 8) \| regnum, &regs->miimadd);

	/* Write out the value we want */
	iowrite32be(value, &regs->miimcon);

	/* Wait for the transaction to finish */
	timeout = MII_TIMEOUT;
	while ((ioread32be(&regs->miimind) & MIIMIND_BUSY) && timeout) {
	cpu_relax();
	timeout--;
	}

	return timeout ? 0 : -ETIMEDOUT;
	}

	/*
	* Read the bus for PHY at addr mii_id, register regnum, and return the value.
	* Clears miimcom first.
	*
	* All PHY operation done on the bus attached to the local interface, which
	* may be different from the generic mdio bus. This is helpful in programming
	* interfaces like the TBI which, in turn, control interfaces like on-chip
	* SERDES and are always tied to the local mdio pins, which may not be the
	* same as system mdio bus, used for controlling the external PHYs, for eg.
	*/
	static int fsl_pq_mdio_read(struct mii_bus *bus, int mii_id, int regnum)
	{
	struct fsl_pq_mdio_priv *priv = bus->priv;
	struct fsl_pq_mii __iomem *regs = priv->regs;
	unsigned int timeout;
	u16 value;

	/* Set the PHY address and the register address we want to read */
	iowrite32be((mii_id << 8) \| regnum, &regs->miimadd);

	/* Clear miimcom, and then initiate a read */
	iowrite32be(0, &regs->miimcom);
	iowrite32be(MII_READ_COMMAND, &regs->miimcom);

	/* Wait for the transaction to finish, normally less than 100us */
	timeout = MII_TIMEOUT;
	while ((ioread32be(&regs->miimind) &
	(MIIMIND_NOTVALID \| MIIMIND_BUSY)) && timeout) {
	cpu_relax();
	timeout--;
	}

	if (!timeout)
	return -ETIMEDOUT;

	/* Grab the value of the register from miimstat */
	value = ioread32be(&regs->miimstat);

	dev_dbg(&bus->dev, "read %04x from address %x/%x\n", value, mii_id, regnum);
	return value;
	}

	/* Reset the MIIM registers, and wait for the bus to free */
	static int fsl_pq_mdio_reset(struct mii_bus *bus)
	{
	struct fsl_pq_mdio_priv *priv = bus->priv;
	struct fsl_pq_mii __iomem *regs = priv->regs;
	unsigned int timeout;

	mutex_lock(&bus->mdio_lock);

	/* Reset the management interface */
	iowrite32be(MIIMCFG_RESET, &regs->miimcfg);

	/* Setup the MII Mgmt clock speed */
	iowrite32be(MIIMCFG_INIT_VALUE, &regs->miimcfg);

	/* Wait until the bus is free */
	timeout = MII_TIMEOUT;
	while ((ioread32be(&regs->miimind) & MIIMIND_BUSY) && timeout) {
	cpu_relax();
	timeout--;
	}

	mutex_unlock(&bus->mdio_lock);

	if (!timeout) {
	dev_err(&bus->dev, "timeout waiting for MII bus\n");
	return -EBUSY;
	}

	return 0;
	}

	#if defined(CONFIG_GIANFAR) \|\| defined(CONFIG_GIANFAR_MODULE)
	/*
	* Return the TBIPA address, starting from the address
	* of the mapped GFAR MDIO registers (struct gfar)
	* This is mildly evil, but so is our hardware for doing this.
	* Also, we have to cast back to struct gfar because of
	* definition weirdness done in gianfar.h.
	*/
	static uint32_t __iomem get_gfar_tbipa_from_mdio(void __iomem p)
	{
	struct gfar __iomem *enet_regs = p;

	return &enet_regs->tbipa;
	}

	/*
	* Return the TBIPA address, starting from the address
	* of the mapped GFAR MII registers (gfar_mii_regs[] within struct gfar)
	*/
	static uint32_t __iomem get_gfar_tbipa_from_mii(void __iomem p)
	{
	return get_gfar_tbipa_from_mdio(container_of(p, struct gfar, gfar_mii_regs));
	}

	/*
	* Return the TBIPAR address for an eTSEC2 node
	*/
	static uint32_t __iomem get_etsec_tbipa(void __iomem p)
	{
	return p;
	}
	#endif

	#if defined(CONFIG_UCC_GETH) \|\| defined(CONFIG_UCC_GETH_MODULE)
	/*
	* Return the TBIPAR address for a QE MDIO node, starting from the address
	* of the mapped MII registers (struct fsl_pq_mii)
	*/
	static uint32_t __iomem get_ucc_tbipa(void __iomem p)
	{
	struct fsl_pq_mdio __iomem *mdio = container_of(p, struct fsl_pq_mdio, mii);

	return &mdio->utbipar;
	}

	/*
	* Find the UCC node that controls the given MDIO node
	*
	* For some reason, the QE MDIO nodes are not children of the UCC devices
	* that control them. Therefore, we need to scan all UCC nodes looking for
	* the one that encompases the given MDIO node. We do this by comparing
	* physical addresses. The 'start' and 'end' addresses of the MDIO node are
	* passed, and the correct UCC node will cover the entire address range.
	*
	* This assumes that there is only one QE MDIO node in the entire device tree.
	*/
	static void ucc_configure(phys_addr_t start, phys_addr_t end)
	{
	static bool found_mii_master;
	struct device_node *np = NULL;

	if (found_mii_master)
	return;

	for_each_compatible_node(np, NULL, "ucc_geth") {
	struct resource res;
	const uint32_t *iprop;
	uint32_t id;
	int ret;

	ret = of_address_to_resource(np, 0, &res);
	if (ret < 0) {
	pr_debug("fsl-pq-mdio: no address range in node %s\n",
	np->full_name);
	continue;
	}

	/* if our mdio regs fall within this UCC regs range */
	if ((start < res.start) \|\| (end > res.end))
	continue;

	iprop = of_get_property(np, "cell-index", NULL);
	if (!iprop) {
	iprop = of_get_property(np, "device-id", NULL);
	if (!iprop) {
	pr_debug("fsl-pq-mdio: no UCC ID in node %s\n",
	np->full_name);
	continue;
	}
	}

	id = be32_to_cpup(iprop);

	/*
	* cell-index and device-id for QE nodes are
	* numbered from 1, not 0.
	*/
	if (ucc_set_qe_mux_mii_mng(id - 1) < 0) {
	pr_debug("fsl-pq-mdio: invalid UCC ID in node %s\n",
	np->full_name);
	continue;
	}

	pr_debug("fsl-pq-mdio: setting node UCC%u to MII master\n", id);
	found_mii_master = true;
	}
	}

	#endif

	static const struct of_device_id fsl_pq_mdio_match[] = {
	#if defined(CONFIG_GIANFAR) \|\| defined(CONFIG_GIANFAR_MODULE)
	{
	.compatible = "fsl,gianfar-tbi",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = 0,
	.get_tbipa = get_gfar_tbipa_from_mii,
	},
	},
	{
	.compatible = "fsl,gianfar-mdio",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = 0,
	.get_tbipa = get_gfar_tbipa_from_mii,
	},
	},
	{
	.type = "mdio",
	.compatible = "gianfar",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = offsetof(struct fsl_pq_mdio, mii),
	.get_tbipa = get_gfar_tbipa_from_mdio,
	},
	},
	{
	.compatible = "fsl,etsec2-tbi",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = offsetof(struct fsl_pq_mdio, mii),
	.get_tbipa = get_etsec_tbipa,
	},
	},
	{
	.compatible = "fsl,etsec2-mdio",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = offsetof(struct fsl_pq_mdio, mii),
	.get_tbipa = get_etsec_tbipa,
	},
	},
	#endif
	#if defined(CONFIG_UCC_GETH) \|\| defined(CONFIG_UCC_GETH_MODULE)
	{
	.compatible = "fsl,ucc-mdio",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = 0,
	.get_tbipa = get_ucc_tbipa,
	.ucc_configure = ucc_configure,
	},
	},
	{
	/* Legacy UCC MDIO node */
	.type = "mdio",
	.compatible = "ucc_geth_phy",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = 0,
	.get_tbipa = get_ucc_tbipa,
	.ucc_configure = ucc_configure,
	},
	},
	#endif
	/* No Kconfig option for Fman support yet */
	{
	.compatible = "fsl,fman-mdio",
	.data = &(struct fsl_pq_mdio_data) {
	.mii_offset = 0,
	/* Fman TBI operations are handled elsewhere */
	},
	},

	{},
	};
	MODULE_DEVICE_TABLE(of, fsl_pq_mdio_match);

	static int fsl_pq_mdio_probe(struct platform_device *pdev)
	{
	const struct of_device_id *id =
	of_match_device(fsl_pq_mdio_match, &pdev->dev);
	const struct fsl_pq_mdio_data *data = id->data;
	struct device_node *np = pdev->dev.of_node;
	struct resource res;
	struct device_node *tbi;
	struct fsl_pq_mdio_priv *priv;
	struct mii_bus *new_bus;
	int err;

	dev_dbg(&pdev->dev, "found %s compatible node\n", id->compatible);

	new_bus = mdiobus_alloc_size(sizeof(*priv));
	if (!new_bus)
	return -ENOMEM;

	priv = new_bus->priv;
	new_bus->name = "Freescale PowerQUICC MII Bus",
	new_bus->read = &fsl_pq_mdio_read;
	new_bus->write = &fsl_pq_mdio_write;
	new_bus->reset = &fsl_pq_mdio_reset;

	err = of_address_to_resource(np, 0, &res);
	if (err < 0) {
	dev_err(&pdev->dev, "could not obtain address information\n");
	goto error;
	}

	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%s@%llx", np->name,
	(unsigned long long)res.start);

	priv->map = of_iomap(np, 0);
	if (!priv->map) {
	err = -ENOMEM;
	goto error;
	}

	/*
	* Some device tree nodes represent only the MII registers, and
	* others represent the MAC and MII registers. The 'mii_offset' field
	* contains the offset of the MII registers inside the mapped register
	* space.
	*/
	if (data->mii_offset > resource_size(&res)) {
	dev_err(&pdev->dev, "invalid register map\n");
	err = -EINVAL;
	goto error;
	}
	priv->regs = priv->map + data->mii_offset;

	new_bus->parent = &pdev->dev;
	platform_set_drvdata(pdev, new_bus);

	if (data->get_tbipa) {
	for_each_child_of_node(np, tbi) {
	if (strcmp(tbi->type, "tbi-phy") == 0) {
	dev_dbg(&pdev->dev, "found TBI PHY node %s\n",
	strrchr(tbi->full_name, '/') + 1);
	break;
	}
	}

	if (tbi) {
	const u32 *prop = of_get_property(tbi, "reg", NULL);
	uint32_t __iomem *tbipa;

	if (!prop) {
	dev_err(&pdev->dev,
	"missing 'reg' property in node %s\n",
	tbi->full_name);
	err = -EBUSY;
	goto error;
	}

	tbipa = data->get_tbipa(priv->map);

	/*
	* Add consistency check to make sure TBI is contained
	* within the mapped range (not because we would get a
	* segfault, rather to catch bugs in computing TBI
	* address). Print error message but continue anyway.
	*/
	if ((void *)tbipa > priv->map + resource_size(&res) - 4)
	dev_err(&pdev->dev, "invalid register map (should be at least 0x%04zx to contain TBI address)\n",
	((void *)tbipa - priv->map) + 4);

	iowrite32be(be32_to_cpup(prop), tbipa);
	}
	}

	if (data->ucc_configure)
	data->ucc_configure(res.start, res.end);

	err = of_mdiobus_register(new_bus, np);
	if (err) {
	dev_err(&pdev->dev, "cannot register %s as MDIO bus\n",
	new_bus->name);
	goto error;
	}

	return 0;

	error:
	if (priv->map)
	iounmap(priv->map);

	kfree(new_bus);

	return err;
	}


	static int fsl_pq_mdio_remove(struct platform_device *pdev)
	{
	struct device *device = &pdev->dev;
	struct mii_bus *bus = dev_get_drvdata(device);
	struct fsl_pq_mdio_priv *priv = bus->priv;

	mdiobus_unregister(bus);

	iounmap(priv->map);
	mdiobus_free(bus);

	return 0;
	}

	static struct platform_driver fsl_pq_mdio_driver = {
	.driver = {
	.name = "fsl-pq_mdio",
	.of_match_table = fsl_pq_mdio_match,
	},
	.probe = fsl_pq_mdio_probe,
	.remove = fsl_pq_mdio_remove,
	};

	module_platform_driver(fsl_pq_mdio_driver);

	MODULE_LICENSE("GPL");