zmii.c

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/*
 * drivers/net/ethernet/ibm/emac/zmii.c
 *
 * Driver for PowerPC 4xx on-chip ethernet controller, ZMII bridge support.
 *
 * Copyright 2007 Benjamin Herrenschmidt, IBM Corp.
 *                <[email protected]>
 *
 * Based on the arch/ppc version of the driver:
 *
 * Copyright (c) 2004, 2005 Zultys Technologies.
 * Eugene Surovegin <[email protected]> or <[email protected]>
 *
 * Based on original work by
 *      Armin Kuster <[email protected]>
 *  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 <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 __devinit zmii_attach(struct platform_device *ofdev, int input, int *mode)
{
    struct zmii_instance *dev = dev_get_drvdata(&ofdev->dev);
    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 = dev_get_drvdata(&ofdev->dev);
    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 = dev_get_drvdata(&ofdev->dev);

    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 = dev_get_drvdata(&ofdev->dev);
    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 = dev_get_drvdata(&ofdev->dev);

    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 = dev_get_drvdata(&ofdev->dev);
    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 __devinit 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();
    dev_set_drvdata(&ofdev->dev, dev);

    return 0;

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

static int __devexit zmii_remove(struct platform_device *ofdev)
{
    struct zmii_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 zmii_match[] =
{
    {
        .compatible = "ibm,zmii",
    },
    /* For backward compat with old DT */
    {
        .type       = "emac-zmii",
    },
    {},
};

static struct platform_driver zmii_driver = {
    .driver = {
        .name = "emac-zmii",
        .owner = THIS_MODULE,
        .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);
}