arch/powerpc/platforms/pasemi/gpio_mdio.c - arm/linux - Git at Google

 /*
  * Copyright (C) 2006-2007 PA Semi, Inc
  *
  * Author: Olof Johansson, PA Semi
  *
  * Maintained by: Olof Johansson <olof@lixom.net>
  *
  * Based on drivers/net/fs_enet/mii-bitbang.c.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License version 2 as
  * published by the Free Software Foundation.
  *
  * This program is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  * GNU General Public License for more details.
  *
  * You should have received a copy of the GNU General Public License
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA
  */

 #include <linux/io.h>
 #include <linux/module.h>
 #include <linux/types.h>
 #include <linux/slab.h>
 #include <linux/sched.h>
 #include <linux/errno.h>
 #include <linux/ioport.h>
 #include <linux/interrupt.h>
 #include <linux/phy.h>
 #include <linux/of_mdio.h>
 #include <linux/of_platform.h>

 #define DELAY 1

 static void __iomem *gpio_regs;

 struct gpio_priv {
 	int mdc_pin;
 	int mdio_pin;
 	int mdio_irqs[PHY_MAX_ADDR];
 };

 #define MDC_PIN(bus)	(((struct gpio_priv *)bus->priv)->mdc_pin)
 #define MDIO_PIN(bus)	(((struct gpio_priv *)bus->priv)->mdio_pin)

 static inline void mdio_lo(struct mii_bus *bus)
 {
 	out_le32(gpio_regs+0x10, 1 << MDIO_PIN(bus));
 }

 static inline void mdio_hi(struct mii_bus *bus)
 {
 	out_le32(gpio_regs, 1 << MDIO_PIN(bus));
 }

 static inline void mdc_lo(struct mii_bus *bus)
 {
 	out_le32(gpio_regs+0x10, 1 << MDC_PIN(bus));
 }

 static inline void mdc_hi(struct mii_bus *bus)
 {
 	out_le32(gpio_regs, 1 << MDC_PIN(bus));
 }

 static inline void mdio_active(struct mii_bus *bus)
 {
 	out_le32(gpio_regs+0x20, (1 << MDC_PIN(bus)) | (1 << MDIO_PIN(bus)));
 }

 static inline void mdio_tristate(struct mii_bus *bus)
 {
 	out_le32(gpio_regs+0x30, (1 << MDIO_PIN(bus)));
 }

 static inline int mdio_read(struct mii_bus *bus)
 {
 	return !!(in_le32(gpio_regs+0x40) & (1 << MDIO_PIN(bus)));
 }

 static void clock_out(struct mii_bus *bus, int bit)
 {
 	if (bit)
 		mdio_hi(bus);
 	else
 		mdio_lo(bus);
 	udelay(DELAY);
 	mdc_hi(bus);
 	udelay(DELAY);
 	mdc_lo(bus);
 }

 /* Utility to send the preamble, address, and register (common to read and write). */
 static void bitbang_pre(struct mii_bus *bus, int read, u8 addr, u8 reg)
 {
 	int i;

 	/* CFE uses a really long preamble (40 bits). We'll do the same. */
 	mdio_active(bus);
 	for (i = 0; i < 40; i++) {
 		clock_out(bus, 1);
 	}

 	/* send the start bit (01) and the read opcode (10) or write (10) */
 	clock_out(bus, 0);
 	clock_out(bus, 1);

 	clock_out(bus, read);
 	clock_out(bus, !read);

 	/* send the PHY address */
 	for (i = 0; i < 5; i++) {
 		clock_out(bus, (addr & 0x10) != 0);
 		addr <<= 1;
 	}

 	/* send the register address */
 	for (i = 0; i < 5; i++) {
 		clock_out(bus, (reg & 0x10) != 0);
 		reg <<= 1;
 	}
 }

 static int gpio_mdio_read(struct mii_bus *bus, int phy_id, int location)
 {
 	u16 rdreg;
 	int ret, i;
 	u8 addr = phy_id & 0xff;
 	u8 reg = location & 0xff;

 	bitbang_pre(bus, 1, addr, reg);

 	/* tri-state our MDIO I/O pin so we can read */
 	mdio_tristate(bus);
 	udelay(DELAY);
 	mdc_hi(bus);
 	udelay(DELAY);
 	mdc_lo(bus);

 	/* read 16 bits of register data, MSB first */
 	rdreg = 0;
 	for (i = 0; i < 16; i++) {
 		mdc_lo(bus);
 		udelay(DELAY);
 		mdc_hi(bus);
 		udelay(DELAY);
 		mdc_lo(bus);
 		udelay(DELAY);
 		rdreg <<= 1;
 		rdreg |= mdio_read(bus);
 	}

 	mdc_hi(bus);
 	udelay(DELAY);
 	mdc_lo(bus);
 	udelay(DELAY);

 	ret = rdreg;

 	return ret;
 }

 static int gpio_mdio_write(struct mii_bus *bus, int phy_id, int location, u16 val)
 {
 	int i;

 	u8 addr = phy_id & 0xff;
 	u8 reg = location & 0xff;
 	u16 value = val & 0xffff;

 	bitbang_pre(bus, 0, addr, reg);

 	/* send the turnaround (10) */
 	mdc_lo(bus);
 	mdio_hi(bus);
 	udelay(DELAY);
 	mdc_hi(bus);
 	udelay(DELAY);
 	mdc_lo(bus);
 	mdio_lo(bus);
 	udelay(DELAY);
 	mdc_hi(bus);
 	udelay(DELAY);

 	/* write 16 bits of register data, MSB first */
 	for (i = 0; i < 16; i++) {
 		mdc_lo(bus);
 		if (value & 0x8000)
 			mdio_hi(bus);
 		else
 			mdio_lo(bus);
 		udelay(DELAY);
 		mdc_hi(bus);
 		udelay(DELAY);
 		value <<= 1;
 	}

 	/*
 	 * Tri-state the MDIO line.
 	 */
 	mdio_tristate(bus);
 	mdc_lo(bus);
 	udelay(DELAY);
 	mdc_hi(bus);
 	udelay(DELAY);
 	return 0;
 }

 static int gpio_mdio_reset(struct mii_bus *bus)
 {
 	/*nothing here - dunno how to reset it*/
 	return 0;
 }


 static int gpio_mdio_probe(struct platform_device *ofdev)
 {
 	struct device *dev = &ofdev->dev;
 	struct device_node *np = ofdev->dev.of_node;
 	struct mii_bus *new_bus;
 	struct gpio_priv *priv;
 	const unsigned int *prop;
 	int err;

 	err = -ENOMEM;
 	priv = kzalloc(sizeof(struct gpio_priv), GFP_KERNEL);
 	if (!priv)
 		goto out;

 	new_bus = mdiobus_alloc();

 	if (!new_bus)
 		goto out_free_priv;

 	new_bus->name = "pasemi gpio mdio bus";
 	new_bus->read = &gpio_mdio_read;
 	new_bus->write = &gpio_mdio_write;
 	new_bus->reset = &gpio_mdio_reset;

 	prop = of_get_property(np, "reg", NULL);
 	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%x", *prop);
 	new_bus->priv = priv;

 	new_bus->irq = priv->mdio_irqs;

 	prop = of_get_property(np, "mdc-pin", NULL);
 	priv->mdc_pin = *prop;

 	prop = of_get_property(np, "mdio-pin", NULL);
 	priv->mdio_pin = *prop;

 	new_bus->parent = dev;
 	dev_set_drvdata(dev, new_bus);

 	err = of_mdiobus_register(new_bus, np);

 	if (err != 0) {
 		printk(KERN_ERR "%s: Cannot register as MDIO bus, err %d\n",
 				new_bus->name, err);
 		goto out_free_irq;
 	}

 	return 0;

 out_free_irq:
 	kfree(new_bus);
 out_free_priv:
 	kfree(priv);
 out:
 	return err;
 }


 static int gpio_mdio_remove(struct platform_device *dev)
 {
 	struct mii_bus *bus = dev_get_drvdata(&dev->dev);

 	mdiobus_unregister(bus);

 	dev_set_drvdata(&dev->dev, NULL);

 	kfree(bus->priv);
 	bus->priv = NULL;
 	mdiobus_free(bus);

 	return 0;
 }

 static struct of_device_id gpio_mdio_match[] =
 {
 	{
 		.compatible      = "gpio-mdio",
 	},
 	{},
 };
 MODULE_DEVICE_TABLE(of, gpio_mdio_match);

 static struct platform_driver gpio_mdio_driver =
 {
 	.probe		= gpio_mdio_probe,
 	.remove		= gpio_mdio_remove,
 	.driver = {
 		.name = "gpio-mdio-bitbang",
 		.owner = THIS_MODULE,
 		.of_match_table = gpio_mdio_match,
 	},
 };

 int gpio_mdio_init(void)
 {
 	struct device_node *np;

 	np = of_find_compatible_node(NULL, NULL, "1682m-gpio");
 	if (!np)
 		np = of_find_compatible_node(NULL, NULL,
 					     "pasemi,pwrficient-gpio");
 	if (!np)
 		return -ENODEV;
 	gpio_regs = of_iomap(np, 0);
 	of_node_put(np);

 	if (!gpio_regs)
 		return -ENODEV;

 	return platform_driver_register(&gpio_mdio_driver);
 }
 module_init(gpio_mdio_init);

 void gpio_mdio_exit(void)
 {
 	platform_driver_unregister(&gpio_mdio_driver);
 	if (gpio_regs)
 		iounmap(gpio_regs);
 }
 module_exit(gpio_mdio_exit);

 MODULE_LICENSE("GPL");
 MODULE_AUTHOR("Olof Johansson <olof@lixom.net>");
 MODULE_DESCRIPTION("Driver for MDIO over GPIO on PA Semi PWRficient-based boards");
	/*
	* Copyright (C) 2006-2007 PA Semi, Inc
	*
	* Author: Olof Johansson, PA Semi
	*
	* Maintained by: Olof Johansson <olof@lixom.net>
	*
	* Based on drivers/net/fs_enet/mii-bitbang.c.
	*
	* This program is free software; you can redistribute it and/or modify
	* it under the terms of the GNU General Public License version 2 as
	* published by the Free Software Foundation.
	*
	* This program is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	* GNU General Public License for more details.
	*
	* You should have received a copy of the GNU General Public License
	* along with this program; if not, write to the Free Software
	* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
	*/

	#include <linux/io.h>
	#include <linux/module.h>
	#include <linux/types.h>
	#include <linux/slab.h>
	#include <linux/sched.h>
	#include <linux/errno.h>
	#include <linux/ioport.h>
	#include <linux/interrupt.h>
	#include <linux/phy.h>
	#include <linux/of_mdio.h>
	#include <linux/of_platform.h>

	#define DELAY 1

	static void __iomem *gpio_regs;

	struct gpio_priv {
	int mdc_pin;
	int mdio_pin;
	int mdio_irqs[PHY_MAX_ADDR];
	};

	#define MDC_PIN(bus) (((struct gpio_priv *)bus->priv)->mdc_pin)
	#define MDIO_PIN(bus) (((struct gpio_priv *)bus->priv)->mdio_pin)

	static inline void mdio_lo(struct mii_bus *bus)
	{
	out_le32(gpio_regs+0x10, 1 << MDIO_PIN(bus));
	}

	static inline void mdio_hi(struct mii_bus *bus)
	{
	out_le32(gpio_regs, 1 << MDIO_PIN(bus));
	}

	static inline void mdc_lo(struct mii_bus *bus)
	{
	out_le32(gpio_regs+0x10, 1 << MDC_PIN(bus));
	}

	static inline void mdc_hi(struct mii_bus *bus)
	{
	out_le32(gpio_regs, 1 << MDC_PIN(bus));
	}

	static inline void mdio_active(struct mii_bus *bus)
	{
	out_le32(gpio_regs+0x20, (1 << MDC_PIN(bus)) \| (1 << MDIO_PIN(bus)));
	}

	static inline void mdio_tristate(struct mii_bus *bus)
	{
	out_le32(gpio_regs+0x30, (1 << MDIO_PIN(bus)));
	}

	static inline int mdio_read(struct mii_bus *bus)
	{
	return !!(in_le32(gpio_regs+0x40) & (1 << MDIO_PIN(bus)));
	}

	static void clock_out(struct mii_bus *bus, int bit)
	{
	if (bit)
	mdio_hi(bus);
	else
	mdio_lo(bus);
	udelay(DELAY);
	mdc_hi(bus);
	udelay(DELAY);
	mdc_lo(bus);
	}

	/* Utility to send the preamble, address, and register (common to read and write). */
	static void bitbang_pre(struct mii_bus *bus, int read, u8 addr, u8 reg)
	{
	int i;

	/* CFE uses a really long preamble (40 bits). We'll do the same. */
	mdio_active(bus);
	for (i = 0; i < 40; i++) {
	clock_out(bus, 1);
	}

	/* send the start bit (01) and the read opcode (10) or write (10) */
	clock_out(bus, 0);
	clock_out(bus, 1);

	clock_out(bus, read);
	clock_out(bus, !read);

	/* send the PHY address */
	for (i = 0; i < 5; i++) {
	clock_out(bus, (addr & 0x10) != 0);
	addr <<= 1;
	}

	/* send the register address */
	for (i = 0; i < 5; i++) {
	clock_out(bus, (reg & 0x10) != 0);
	reg <<= 1;
	}
	}

	static int gpio_mdio_read(struct mii_bus *bus, int phy_id, int location)
	{
	u16 rdreg;
	int ret, i;
	u8 addr = phy_id & 0xff;
	u8 reg = location & 0xff;

	bitbang_pre(bus, 1, addr, reg);

	/* tri-state our MDIO I/O pin so we can read */
	mdio_tristate(bus);
	udelay(DELAY);
	mdc_hi(bus);
	udelay(DELAY);
	mdc_lo(bus);

	/* read 16 bits of register data, MSB first */
	rdreg = 0;
	for (i = 0; i < 16; i++) {
	mdc_lo(bus);
	udelay(DELAY);
	mdc_hi(bus);
	udelay(DELAY);
	mdc_lo(bus);
	udelay(DELAY);
	rdreg <<= 1;
	rdreg \|= mdio_read(bus);
	}

	mdc_hi(bus);
	udelay(DELAY);
	mdc_lo(bus);
	udelay(DELAY);

	ret = rdreg;

	return ret;
	}

	static int gpio_mdio_write(struct mii_bus *bus, int phy_id, int location, u16 val)
	{
	int i;

	u8 addr = phy_id & 0xff;
	u8 reg = location & 0xff;
	u16 value = val & 0xffff;

	bitbang_pre(bus, 0, addr, reg);

	/* send the turnaround (10) */
	mdc_lo(bus);
	mdio_hi(bus);
	udelay(DELAY);
	mdc_hi(bus);
	udelay(DELAY);
	mdc_lo(bus);
	mdio_lo(bus);
	udelay(DELAY);
	mdc_hi(bus);
	udelay(DELAY);

	/* write 16 bits of register data, MSB first */
	for (i = 0; i < 16; i++) {
	mdc_lo(bus);
	if (value & 0x8000)
	mdio_hi(bus);
	else
	mdio_lo(bus);
	udelay(DELAY);
	mdc_hi(bus);
	udelay(DELAY);
	value <<= 1;
	}

	/*
	* Tri-state the MDIO line.
	*/
	mdio_tristate(bus);
	mdc_lo(bus);
	udelay(DELAY);
	mdc_hi(bus);
	udelay(DELAY);
	return 0;
	}

	static int gpio_mdio_reset(struct mii_bus *bus)
	{
	/nothing here - dunno how to reset it/
	return 0;
	}


	static int gpio_mdio_probe(struct platform_device *ofdev)
	{
	struct device *dev = &ofdev->dev;
	struct device_node *np = ofdev->dev.of_node;
	struct mii_bus *new_bus;
	struct gpio_priv *priv;
	const unsigned int *prop;
	int err;

	err = -ENOMEM;
	priv = kzalloc(sizeof(struct gpio_priv), GFP_KERNEL);
	if (!priv)
	goto out;

	new_bus = mdiobus_alloc();

	if (!new_bus)
	goto out_free_priv;

	new_bus->name = "pasemi gpio mdio bus";
	new_bus->read = &gpio_mdio_read;
	new_bus->write = &gpio_mdio_write;
	new_bus->reset = &gpio_mdio_reset;

	prop = of_get_property(np, "reg", NULL);
	snprintf(new_bus->id, MII_BUS_ID_SIZE, "%x", *prop);
	new_bus->priv = priv;

	new_bus->irq = priv->mdio_irqs;

	prop = of_get_property(np, "mdc-pin", NULL);
	priv->mdc_pin = *prop;

	prop = of_get_property(np, "mdio-pin", NULL);
	priv->mdio_pin = *prop;

	new_bus->parent = dev;
	dev_set_drvdata(dev, new_bus);

	err = of_mdiobus_register(new_bus, np);

	if (err != 0) {
	printk(KERN_ERR "%s: Cannot register as MDIO bus, err %d\n",
	new_bus->name, err);
	goto out_free_irq;
	}

	return 0;

	out_free_irq:
	kfree(new_bus);
	out_free_priv:
	kfree(priv);
	out:
	return err;
	}


	static int gpio_mdio_remove(struct platform_device *dev)
	{
	struct mii_bus *bus = dev_get_drvdata(&dev->dev);

	mdiobus_unregister(bus);

	dev_set_drvdata(&dev->dev, NULL);

	kfree(bus->priv);
	bus->priv = NULL;
	mdiobus_free(bus);

	return 0;
	}

	static struct of_device_id gpio_mdio_match[] =
	{
	{
	.compatible = "gpio-mdio",
	},
	{},
	};
	MODULE_DEVICE_TABLE(of, gpio_mdio_match);

	static struct platform_driver gpio_mdio_driver =
	{
	.probe = gpio_mdio_probe,
	.remove = gpio_mdio_remove,
	.driver = {
	.name = "gpio-mdio-bitbang",
	.owner = THIS_MODULE,
	.of_match_table = gpio_mdio_match,
	},
	};

	int gpio_mdio_init(void)
	{
	struct device_node *np;

	np = of_find_compatible_node(NULL, NULL, "1682m-gpio");
	if (!np)
	np = of_find_compatible_node(NULL, NULL,
	"pasemi,pwrficient-gpio");
	if (!np)
	return -ENODEV;
	gpio_regs = of_iomap(np, 0);
	of_node_put(np);

	if (!gpio_regs)
	return -ENODEV;

	return platform_driver_register(&gpio_mdio_driver);
	}
	module_init(gpio_mdio_init);

	void gpio_mdio_exit(void)
	{
	platform_driver_unregister(&gpio_mdio_driver);
	if (gpio_regs)
	iounmap(gpio_regs);
	}
	module_exit(gpio_mdio_exit);

	MODULE_LICENSE("GPL");
	MODULE_AUTHOR("Olof Johansson <olof@lixom.net>");
	MODULE_DESCRIPTION("Driver for MDIO over GPIO on PA Semi PWRficient-based boards");