text: /*
   * drivers/net/ethernet/ibm/emac/zmii.c
   *
   * Driver for PowerPC 4xx on-chip ethernet controller, ZMII bridge support.
   *
   * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
   *                <benh@kernel.crashing.org>
   *
   * Based on the arch/ppc version of the driver:
   *
   * Copyright (c) 2004, 2005 Zultys Technologies.
   * Eugene Surovegin <eugene.surovegin@zultys.com> or <ebs@ebshome.net>
   *
   * Based on original work by
   *      Armin Kuster <akuster@mvista.com>
   * 	Copyright 2001 MontaVista Softare Inc.
   *
   * 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/slab.h>
  #include <linux/kernel.h>
  #include <linux/ethtool.h>
  #include <linux/of_address.h>
  #include <asm/io.h>
  
  #include "emac.h"
  #include "core.h"
  
  /* ZMIIx_FER */
  #define ZMII_FER_MDI(idx)	(0x80000000 >> ((idx) * 4))
  #define ZMII_FER_MDI_ALL	(ZMII_FER_MDI(0) | ZMII_FER_MDI(1) | \
  				 ZMII_FER_MDI(2) | ZMII_FER_MDI(3))
  
  #define ZMII_FER_SMII(idx)	(0x40000000 >> ((idx) * 4))
  #define ZMII_FER_RMII(idx)	(0x20000000 >> ((idx) * 4))
  #define ZMII_FER_MII(idx)	(0x10000000 >> ((idx) * 4))
  
  /* ZMIIx_SSR */
  #define ZMII_SSR_SCI(idx)	(0x40000000 >> ((idx) * 4))
  #define ZMII_SSR_FSS(idx)	(0x20000000 >> ((idx) * 4))
  #define ZMII_SSR_SP(idx)	(0x10000000 >> ((idx) * 4))
  
  /* ZMII only supports MII, RMII and SMII
   * we also support autodetection for backward compatibility
   */
  static inline int zmii_valid_mode(int mode)
  {
  	return  mode == PHY_MODE_MII ||
  		mode == PHY_MODE_RMII ||
  		mode == PHY_MODE_SMII ||
  		mode == PHY_MODE_NA;
  }
  
  static inline const char *zmii_mode_name(int mode)
  {
  	switch (mode) {
  	case PHY_MODE_MII:
  		return "MII";
  	case PHY_MODE_RMII:
  		return "RMII";
  	case PHY_MODE_SMII:
  		return "SMII";
  	default:
  		BUG();
  	}
  }
  
  static inline u32 zmii_mode_mask(int mode, int input)
  {
  	switch (mode) {
  	case PHY_MODE_MII:
  		return ZMII_FER_MII(input);
  	case PHY_MODE_RMII:
  		return ZMII_FER_RMII(input);
  	case PHY_MODE_SMII:
  		return ZMII_FER_SMII(input);
  	default:
  		return 0;
  	}
  }
  
  int zmii_attach(struct platform_device *ofdev, int input, int *mode)
  {
  	struct zmii_instance *dev = platform_get_drvdata(ofdev);
  	struct zmii_regs __iomem *p = dev->base;
  
  	ZMII_DBG(dev, "init(%d, %d)" NL, input, *mode);
  
  	if (!zmii_valid_mode(*mode)) {
  		/* Probably an EMAC connected to RGMII,
  		 * but it still may need ZMII for MDIO so
  		 * we don't fail here.
  		 */
  		dev->users++;
  		return 0;
  	}
  
  	mutex_lock(&dev->lock);
  
  	/* Autodetect ZMII mode if not specified.
  	 * This is only for backward compatibility with the old driver.
  	 * Please, always specify PHY mode in your board port to avoid
  	 * any surprises.
  	 */
  	if (dev->mode == PHY_MODE_NA) {
  		if (*mode == PHY_MODE_NA) {
  			u32 r = dev->fer_save;
  
  			ZMII_DBG(dev, "autodetecting mode, FER = 0x%08x" NL, r);
  
  			if (r & (ZMII_FER_MII(0) | ZMII_FER_MII(1)))
  				dev->mode = PHY_MODE_MII;
  			else if (r & (ZMII_FER_RMII(0) | ZMII_FER_RMII(1)))
  				dev->mode = PHY_MODE_RMII;
  			else
  				dev->mode = PHY_MODE_SMII;
  		} else
  			dev->mode = *mode;
  
  		printk(KERN_NOTICE "%s: bridge in %s mode\n",
  		       ofdev->dev.of_node->full_name,
  		       zmii_mode_name(dev->mode));
  	} else {
  		/* All inputs must use the same mode */
  		if (*mode != PHY_MODE_NA && *mode != dev->mode) {
  			printk(KERN_ERR
  			       "%s: invalid mode %d specified for input %d\n",
  			       ofdev->dev.of_node->full_name, *mode, input);
  			mutex_unlock(&dev->lock);
  			return -EINVAL;
  		}
  	}
  
  	/* Report back correct PHY mode,
  	 * it may be used during PHY initialization.
  	 */
  	*mode = dev->mode;
  
  	/* Enable this input */
  	out_be32(&p->fer, in_be32(&p->fer) | zmii_mode_mask(dev->mode, input));
  	++dev->users;
  
  	mutex_unlock(&dev->lock);
  
  	return 0;
  }
  
  void zmii_get_mdio(struct platform_device *ofdev, int input)
  {
  	struct zmii_instance *dev = platform_get_drvdata(ofdev);
  	u32 fer;
  
  	ZMII_DBG2(dev, "get_mdio(%d)" NL, input);
  
  	mutex_lock(&dev->lock);
  
  	fer = in_be32(&dev->base->fer) & ~ZMII_FER_MDI_ALL;
  	out_be32(&dev->base->fer, fer | ZMII_FER_MDI(input));
  }
  
  void zmii_put_mdio(struct platform_device *ofdev, int input)
  {
  	struct zmii_instance *dev = platform_get_drvdata(ofdev);
  
  	ZMII_DBG2(dev, "put_mdio(%d)" NL, input);
  	mutex_unlock(&dev->lock);
  }
  
  
  void zmii_set_speed(struct platform_device *ofdev, int input, int speed)
  {
  	struct zmii_instance *dev = platform_get_drvdata(ofdev);
  	u32 ssr;
  
  	mutex_lock(&dev->lock);
  
  	ssr = in_be32(&dev->base->ssr);
  
  	ZMII_DBG(dev, "speed(%d, %d)" NL, input, speed);
  
  	if (speed == SPEED_100)
  		ssr |= ZMII_SSR_SP(input);
  	else
  		ssr &= ~ZMII_SSR_SP(input);
  
  	out_be32(&dev->base->ssr, ssr);
  
  	mutex_unlock(&dev->lock);
  }
  
  void zmii_detach(struct platform_device *ofdev, int input)
  {
  	struct zmii_instance *dev = platform_get_drvdata(ofdev);
  
  	BUG_ON(!dev || dev->users == 0);
  
  	mutex_lock(&dev->lock);
  
  	ZMII_DBG(dev, "detach(%d)" NL, input);
  
  	/* Disable this input */
  	out_be32(&dev->base->fer,
  		 in_be32(&dev->base->fer) & ~zmii_mode_mask(dev->mode, input));
  
  	--dev->users;
  
  	mutex_unlock(&dev->lock);
  }
  
  int zmii_get_regs_len(struct platform_device *ofdev)
  {
  	return sizeof(struct emac_ethtool_regs_subhdr) +
  		sizeof(struct zmii_regs);
  }
  
  void *zmii_dump_regs(struct platform_device *ofdev, void *buf)
  {
  	struct zmii_instance *dev = platform_get_drvdata(ofdev);
  	struct emac_ethtool_regs_subhdr *hdr = buf;
  	struct zmii_regs *regs = (struct zmii_regs *)(hdr + 1);
  
  	hdr->version = 0;
  	hdr->index = 0; /* for now, are there chips with more than one
  			 * zmii ? if yes, then we'll add a cell_index
  			 * like we do for emac
  			 */
  	memcpy_fromio(regs, dev->base, sizeof(struct zmii_regs));
  	return regs + 1;
  }
  
  static int zmii_probe(struct platform_device *ofdev)
  {
  	struct device_node *np = ofdev->dev.of_node;
  	struct zmii_instance *dev;
  	struct resource regs;
  	int rc;
  
  	rc = -ENOMEM;
  	dev = kzalloc(sizeof(struct zmii_instance), GFP_KERNEL);
  	if (dev == NULL)
  		goto err_gone;
  
  	mutex_init(&dev->lock);
  	dev->ofdev = ofdev;
  	dev->mode = PHY_MODE_NA;
  
  	rc = -ENXIO;
  	if (of_address_to_resource(np, 0, &regs)) {
  		printk(KERN_ERR "%s: Can't get registers address\n",
  		       np->full_name);
  		goto err_free;
  	}
  
  	rc = -ENOMEM;
  	dev->base = (struct zmii_regs __iomem *)ioremap(regs.start,
  						sizeof(struct zmii_regs));
  	if (dev->base == NULL) {
  		printk(KERN_ERR "%s: Can't map device registers!\n",
  		       np->full_name);
  		goto err_free;
  	}
  
  	/* We may need FER value for autodetection later */
  	dev->fer_save = in_be32(&dev->base->fer);
  
  	/* Disable all inputs by default */
  	out_be32(&dev->base->fer, 0);
  
  	printk(KERN_INFO
  	       "ZMII %s initialized\n", ofdev->dev.of_node->full_name);
  	wmb();
  	platform_set_drvdata(ofdev, dev);
  
  	return 0;
  
   err_free:
  	kfree(dev);
   err_gone:
  	return rc;
  }
  
  static int zmii_remove(struct platform_device *ofdev)
  {
  	struct zmii_instance *dev = platform_get_drvdata(ofdev);
  
  	WARN_ON(dev->users != 0);
  
  	iounmap(dev->base);
  	kfree(dev);
  
  	return 0;
  }
  
  static const struct of_device_id zmii_match[] =
  {
  	{
  		.compatible	= "ibm,zmii",
  	},
  	/* For backward compat with old DT */
  	{
  		.type		= "emac-zmii",
  	},
  	{},
  };
  
  static struct platform_driver zmii_driver = {
  	.driver = {
  		.name = "emac-zmii",
  		.of_match_table = zmii_match,
  	},
  	.probe = zmii_probe,
  	.remove = zmii_remove,
  };
  
  int __init zmii_init(void)
  {
  	return platform_driver_register(&zmii_driver);
  }
  
  void zmii_exit(void)
  {
  	platform_driver_unregister(&zmii_driver);
  }
  