tah.c

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/*
 * drivers/net/ethernet/ibm/emac/tah.c
 *
 * Driver for PowerPC 4xx on-chip ethernet controller, TAH support.
 *
 * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
 *                <[email protected]>
 *
 * Based on the arch/ppc version of the driver:
 *
 * Copyright 2004 MontaVista Software, Inc.
 * Matt Porter <[email protected]>
 *
 * Copyright (c) 2005 Eugene Surovegin <[email protected]>
 *
 * 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 <asm/io.h>

#include "emac.h"
#include "core.h"

int __devinit tah_attach(struct platform_device *ofdev, int channel)
{
    struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);

    mutex_lock(&dev->lock);
    /* Reset has been done at probe() time... nothing else to do for now */
    ++dev->users;
    mutex_unlock(&dev->lock);

    return 0;
}

void tah_detach(struct platform_device *ofdev, int channel)
{
    struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);

    mutex_lock(&dev->lock);
    --dev->users;
    mutex_unlock(&dev->lock);
}

void tah_reset(struct platform_device *ofdev)
{
    struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
    struct tah_regs __iomem *p = dev->base;
    int n;

    /* Reset TAH */
    out_be32(&p->mr, TAH_MR_SR);
    n = 100;
    while ((in_be32(&p->mr) & TAH_MR_SR) && n)
        --n;

    if (unlikely(!n))
        printk(KERN_ERR "%s: reset timeout\n",
            ofdev->dev.of_node->full_name);

    /* 10KB TAH TX FIFO accommodates the max MTU of 9000 */
    out_be32(&p->mr,
         TAH_MR_CVR | TAH_MR_ST_768 | TAH_MR_TFS_10KB | TAH_MR_DTFP |
         TAH_MR_DIG);
}

int tah_get_regs_len(struct platform_device *ofdev)
{
    return sizeof(struct emac_ethtool_regs_subhdr) +
        sizeof(struct tah_regs);
}

void *tah_dump_regs(struct platform_device *ofdev, void *buf)
{
    struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);
    struct emac_ethtool_regs_subhdr *hdr = buf;
    struct tah_regs *regs = (struct tah_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 tah_regs));
    return regs + 1;
}

static int __devinit tah_probe(struct platform_device *ofdev)
{
    struct device_node *np = ofdev->dev.of_node;
    struct tah_instance *dev;
    struct resource regs;
    int rc;

    rc = -ENOMEM;
    dev = kzalloc(sizeof(struct tah_instance), GFP_KERNEL);
    if (dev == NULL)
        goto err_gone;

    mutex_init(&dev->lock);
    dev->ofdev = ofdev;

    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 tah_regs __iomem *)ioremap(regs.start,
                           sizeof(struct tah_regs));
    if (dev->base == NULL) {
        printk(KERN_ERR "%s: Can't map device registers!\n",
               np->full_name);
        goto err_free;
    }

    dev_set_drvdata(&ofdev->dev, dev);

    /* Initialize TAH and enable IPv4 checksum verification, no TSO yet */
    tah_reset(ofdev);

    printk(KERN_INFO
           "TAH %s initialized\n", ofdev->dev.of_node->full_name);
    wmb();

    return 0;

 err_free:
    kfree(dev);
 err_gone:
    return rc;
}

static int __devexit tah_remove(struct platform_device *ofdev)
{
    struct tah_instance *dev = dev_get_drvdata(&ofdev->dev);

    dev_set_drvdata(&ofdev->dev, NULL);

    WARN_ON(dev->users != 0);

    iounmap(dev->base);
    kfree(dev);

    return 0;
}

static struct of_device_id tah_match[] =
{
    {
        .compatible = "ibm,tah",
    },
    /* For backward compat with old DT */
    {
        .type       = "tah",
    },
    {},
};

static struct platform_driver tah_driver = {
    .driver = {
        .name = "emac-tah",
        .owner = THIS_MODULE,
        .of_match_table = tah_match,
    },
    .probe = tah_probe,
    .remove = tah_remove,
};

int __init tah_init(void)
{
    return platform_driver_register(&tah_driver);
}

void tah_exit(void)
{
    platform_driver_unregister(&tah_driver);
}