fixed.c

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/*
 * Fixed MDIO bus (MDIO bus emulation with fixed PHYs)
 *
 * Author: Vitaly Bordug <[email protected]>
 *         Anton Vorontsov <[email protected]>
 *
 * Copyright (c) 2006-2007 MontaVista Software, 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/kernel.h>
#include <linux/module.h>
#include <linux/platform_device.h>
#include <linux/list.h>
#include <linux/mii.h>
#include <linux/phy.h>
#include <linux/phy_fixed.h>
#include <linux/err.h>
#include <linux/slab.h>

#define MII_REGS_NUM 29

struct fixed_mdio_bus {
    int irqs[PHY_MAX_ADDR];
    struct mii_bus *mii_bus;
    struct list_head phys;
};

struct fixed_phy {
    int id;
    u16 regs[MII_REGS_NUM];
    struct phy_device *phydev;
    struct fixed_phy_status status;
    int (*link_update)(struct net_device *, struct fixed_phy_status *);
    struct list_head node;
};

static struct platform_device *pdev;
static struct fixed_mdio_bus platform_fmb = {
    .phys = LIST_HEAD_INIT(platform_fmb.phys),
};

static int fixed_phy_update_regs(struct fixed_phy *fp)
{
    u16 bmsr = BMSR_ANEGCAPABLE;
    u16 bmcr = 0;
    u16 lpagb = 0;
    u16 lpa = 0;

    if (fp->status.duplex) {
        bmcr |= BMCR_FULLDPLX;

        switch (fp->status.speed) {
        case 1000:
            bmsr |= BMSR_ESTATEN;
            bmcr |= BMCR_SPEED1000;
            lpagb |= LPA_1000FULL;
            break;
        case 100:
            bmsr |= BMSR_100FULL;
            bmcr |= BMCR_SPEED100;
            lpa |= LPA_100FULL;
            break;
        case 10:
            bmsr |= BMSR_10FULL;
            lpa |= LPA_10FULL;
            break;
        default:
            pr_warn("fixed phy: unknown speed\n");
            return -EINVAL;
        }
    } else {
        switch (fp->status.speed) {
        case 1000:
            bmsr |= BMSR_ESTATEN;
            bmcr |= BMCR_SPEED1000;
            lpagb |= LPA_1000HALF;
            break;
        case 100:
            bmsr |= BMSR_100HALF;
            bmcr |= BMCR_SPEED100;
            lpa |= LPA_100HALF;
            break;
        case 10:
            bmsr |= BMSR_10HALF;
            lpa |= LPA_10HALF;
            break;
        default:
            pr_warn("fixed phy: unknown speed\n");
            return -EINVAL;
        }
    }

    if (fp->status.link)
        bmsr |= BMSR_LSTATUS | BMSR_ANEGCOMPLETE;

    if (fp->status.pause)
        lpa |= LPA_PAUSE_CAP;

    if (fp->status.asym_pause)
        lpa |= LPA_PAUSE_ASYM;

    fp->regs[MII_PHYSID1] = fp->id >> 16;
    fp->regs[MII_PHYSID2] = fp->id;

    fp->regs[MII_BMSR] = bmsr;
    fp->regs[MII_BMCR] = bmcr;
    fp->regs[MII_LPA] = lpa;
    fp->regs[MII_STAT1000] = lpagb;

    return 0;
}

static int fixed_mdio_read(struct mii_bus *bus, int phy_id, int reg_num)
{
    struct fixed_mdio_bus *fmb = bus->priv;
    struct fixed_phy *fp;

    if (reg_num >= MII_REGS_NUM)
        return -1;

    list_for_each_entry(fp, &fmb->phys, node) {
        if (fp->id == phy_id) {
            /* Issue callback if user registered it. */
            if (fp->link_update) {
                fp->link_update(fp->phydev->attached_dev,
                        &fp->status);
                fixed_phy_update_regs(fp);
            }
            return fp->regs[reg_num];
        }
    }

    return 0xFFFF;
}

static int fixed_mdio_write(struct mii_bus *bus, int phy_id, int reg_num,
                u16 val)
{
    return 0;
}

/*
 * If something weird is required to be done with link/speed,
 * network driver is able to assign a function to implement this.
 * May be useful for PHY's that need to be software-driven.
 */
int fixed_phy_set_link_update(struct phy_device *phydev,
                  int (*link_update)(struct net_device *,
                         struct fixed_phy_status *))
{
    struct fixed_mdio_bus *fmb = &platform_fmb;
    struct fixed_phy *fp;

    if (!link_update || !phydev || !phydev->bus)
        return -EINVAL;

    list_for_each_entry(fp, &fmb->phys, node) {
        if (fp->id == phydev->phy_id) {
            fp->link_update = link_update;
            fp->phydev = phydev;
            return 0;
        }
    }

    return -ENOENT;
}
EXPORT_SYMBOL_GPL(fixed_phy_set_link_update);

int fixed_phy_add(unsigned int irq, int phy_id,
          struct fixed_phy_status *status)
{
    int ret;
    struct fixed_mdio_bus *fmb = &platform_fmb;
    struct fixed_phy *fp;

    fp = kzalloc(sizeof(*fp), GFP_KERNEL);
    if (!fp)
        return -ENOMEM;

    memset(fp->regs, 0xFF,  sizeof(fp->regs[0]) * MII_REGS_NUM);

    fmb->irqs[phy_id] = irq;

    fp->id = phy_id;
    fp->status = *status;

    ret = fixed_phy_update_regs(fp);
    if (ret)
        goto err_regs;

    list_add_tail(&fp->node, &fmb->phys);

    return 0;

err_regs:
    kfree(fp);
    return ret;
}
EXPORT_SYMBOL_GPL(fixed_phy_add);

static int __init fixed_mdio_bus_init(void)
{
    struct fixed_mdio_bus *fmb = &platform_fmb;
    int ret;

    pdev = platform_device_register_simple("Fixed MDIO bus", 0, NULL, 0);
    if (IS_ERR(pdev)) {
        ret = PTR_ERR(pdev);
        goto err_pdev;
    }

    fmb->mii_bus = mdiobus_alloc();
    if (fmb->mii_bus == NULL) {
        ret = -ENOMEM;
        goto err_mdiobus_reg;
    }

    snprintf(fmb->mii_bus->id, MII_BUS_ID_SIZE, "fixed-0");
    fmb->mii_bus->name = "Fixed MDIO Bus";
    fmb->mii_bus->priv = fmb;
    fmb->mii_bus->parent = &pdev->dev;
    fmb->mii_bus->read = &fixed_mdio_read;
    fmb->mii_bus->write = &fixed_mdio_write;
    fmb->mii_bus->irq = fmb->irqs;

    ret = mdiobus_register(fmb->mii_bus);
    if (ret)
        goto err_mdiobus_alloc;

    return 0;

err_mdiobus_alloc:
    mdiobus_free(fmb->mii_bus);
err_mdiobus_reg:
    platform_device_unregister(pdev);
err_pdev:
    return ret;
}
module_init(fixed_mdio_bus_init);

static void __exit fixed_mdio_bus_exit(void)
{
    struct fixed_mdio_bus *fmb = &platform_fmb;
    struct fixed_phy *fp, *tmp;

    mdiobus_unregister(fmb->mii_bus);
    mdiobus_free(fmb->mii_bus);
    platform_device_unregister(pdev);

    list_for_each_entry_safe(fp, tmp, &fmb->phys, node) {
        list_del(&fp->node);
        kfree(fp);
    }
}
module_exit(fixed_mdio_bus_exit);

MODULE_DESCRIPTION("Fixed MDIO bus (MDIO bus emulation with fixed PHYs)");
MODULE_AUTHOR("Vitaly Bordug");
MODULE_LICENSE("GPL");