text: /*
   * Combined Ethernet driver for Motorola MPC8xx and MPC82xx.
   *
   * Copyright (c) 2003 Intracom S.A.
   *  by Pantelis Antoniou <panto@intracom.gr>
   *
   * 2005 (c) MontaVista Software, Inc.
   * Vitaly Bordug <vbordug@ru.mvista.com>
   *
   * This file is licensed under the terms of the GNU General Public License
   * version 2. This program is licensed "as is" without any warranty of any
   * kind, whether express or implied.
   */
  
  #include <linux/module.h>
  #include <linux/ioport.h>
  #include <linux/slab.h>
  #include <linux/init.h>
  #include <linux/interrupt.h>
  #include <linux/netdevice.h>
  #include <linux/etherdevice.h>
  #include <linux/mii.h>
  #include <linux/platform_device.h>
  #include <linux/mdio-bitbang.h>
  #include <linux/of_mdio.h>
  #include <linux/of_platform.h>
  
  #include "fs_enet.h"
  
  struct bb_info {
  	struct mdiobb_ctrl ctrl;
  	__be32 __iomem *dir;
  	__be32 __iomem *dat;
  	u32 mdio_msk;
  	u32 mdc_msk;
  };
  
  /* FIXME: If any other users of GPIO crop up, then these will have to
   * have some sort of global synchronization to avoid races with other
   * pins on the same port.  The ideal solution would probably be to
   * bind the ports to a GPIO driver, and have this be a client of it.
   */
  static inline void bb_set(u32 __iomem *p, u32 m)
  {
  	out_be32(p, in_be32(p) | m);
  }
  
  static inline void bb_clr(u32 __iomem *p, u32 m)
  {
  	out_be32(p, in_be32(p) & ~m);
  }
  
  static inline int bb_read(u32 __iomem *p, u32 m)
  {
  	return (in_be32(p) & m) != 0;
  }
  
  static inline void mdio_dir(struct mdiobb_ctrl *ctrl, int dir)
  {
  	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  
  	if (dir)
  		bb_set(bitbang->dir, bitbang->mdio_msk);
  	else
  		bb_clr(bitbang->dir, bitbang->mdio_msk);
  
  	/* Read back to flush the write. */
  	in_be32(bitbang->dir);
  }
  
  static inline int mdio_read(struct mdiobb_ctrl *ctrl)
  {
  	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  	return bb_read(bitbang->dat, bitbang->mdio_msk);
  }
  
  static inline void mdio(struct mdiobb_ctrl *ctrl, int what)
  {
  	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  
  	if (what)
  		bb_set(bitbang->dat, bitbang->mdio_msk);
  	else
  		bb_clr(bitbang->dat, bitbang->mdio_msk);
  
  	/* Read back to flush the write. */
  	in_be32(bitbang->dat);
  }
  
  static inline void mdc(struct mdiobb_ctrl *ctrl, int what)
  {
  	struct bb_info *bitbang = container_of(ctrl, struct bb_info, ctrl);
  
  	if (what)
  		bb_set(bitbang->dat, bitbang->mdc_msk);
  	else
  		bb_clr(bitbang->dat, bitbang->mdc_msk);
  
  	/* Read back to flush the write. */
  	in_be32(bitbang->dat);
  }
  
  static struct mdiobb_ops bb_ops = {
  	.owner = THIS_MODULE,
  	.set_mdc = mdc,
  	.set_mdio_dir = mdio_dir,
  	.set_mdio_data = mdio,
  	.get_mdio_data = mdio_read,
  };
  
  static int __devinit fs_mii_bitbang_init(struct mii_bus *bus,
                                           struct device_node *np)
  {
  	struct resource res;
  	const u32 *data;
  	int mdio_pin, mdc_pin, len;
  	struct bb_info *bitbang = bus->priv;
  
  	int ret = of_address_to_resource(np, 0, &res);
  	if (ret)
  		return ret;
  
  	if (resource_size(&res) <= 13)
  		return -ENODEV;
  
  	/* This should really encode the pin number as well, but all
  	 * we get is an int, and the odds of multiple bitbang mdio buses
  	 * is low enough that it's not worth going too crazy.
  	 */
  	snprintf(bus->id, MII_BUS_ID_SIZE, "%x", res.start);
  
  	data = of_get_property(np, "fsl,mdio-pin", &len);
  	if (!data || len != 4)
  		return -ENODEV;
  	mdio_pin = *data;
  
  	data = of_get_property(np, "fsl,mdc-pin", &len);
  	if (!data || len != 4)
  		return -ENODEV;
  	mdc_pin = *data;
  
  	bitbang->dir = ioremap(res.start, resource_size(&res));
  	if (!bitbang->dir)
  		return -ENOMEM;
  
  	bitbang->dat = bitbang->dir + 4;
  	bitbang->mdio_msk = 1 << (31 - mdio_pin);
  	bitbang->mdc_msk = 1 << (31 - mdc_pin);
  
  	return 0;
  }
  
  static int __devinit fs_enet_mdio_probe(struct platform_device *ofdev)
  {
  	struct mii_bus *new_bus;
  	struct bb_info *bitbang;
  	int ret = -ENOMEM;
  
  	bitbang = kzalloc(sizeof(struct bb_info), GFP_KERNEL);
  	if (!bitbang)
  		goto out;
  
  	bitbang->ctrl.ops = &bb_ops;
  
  	new_bus = alloc_mdio_bitbang(&bitbang->ctrl);
  	if (!new_bus)
  		goto out_free_priv;
  
  	new_bus->name = "CPM2 Bitbanged MII",
  
  	ret = fs_mii_bitbang_init(new_bus, ofdev->dev.of_node);
  	if (ret)
  		goto out_free_bus;
  
  	new_bus->phy_mask = ~0;
  	new_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
  	if (!new_bus->irq)
  		goto out_unmap_regs;
  
  	new_bus->parent = &ofdev->dev;
  	dev_set_drvdata(&ofdev->dev, new_bus);
  
  	ret = of_mdiobus_register(new_bus, ofdev->dev.of_node);
  	if (ret)
  		goto out_free_irqs;
  
  	return 0;
  
  out_free_irqs:
  	dev_set_drvdata(&ofdev->dev, NULL);
  	kfree(new_bus->irq);
  out_unmap_regs:
  	iounmap(bitbang->dir);
  out_free_bus:
  	free_mdio_bitbang(new_bus);
  out_free_priv:
  	kfree(bitbang);
  out:
  	return ret;
  }
  
  static int fs_enet_mdio_remove(struct platform_device *ofdev)
  {
  	struct mii_bus *bus = dev_get_drvdata(&ofdev->dev);
  	struct bb_info *bitbang = bus->priv;
  
  	mdiobus_unregister(bus);
  	dev_set_drvdata(&ofdev->dev, NULL);
  	kfree(bus->irq);
  	free_mdio_bitbang(bus);
  	iounmap(bitbang->dir);
  	kfree(bitbang);
  
  	return 0;
  }
  
  static struct of_device_id fs_enet_mdio_bb_match[] = {
  	{
  		.compatible = "fsl,cpm2-mdio-bitbang",
  	},
  	{},
  };
  MODULE_DEVICE_TABLE(of, fs_enet_mdio_bb_match);
  
  static struct platform_driver fs_enet_bb_mdio_driver = {
  	.driver = {
  		.name = "fsl-bb-mdio",
  		.owner = THIS_MODULE,
  		.of_match_table = fs_enet_mdio_bb_match,
  	},
  	.probe = fs_enet_mdio_probe,
  	.remove = fs_enet_mdio_remove,
  };
  
  module_platform_driver(fs_enet_bb_mdio_driver);
  