national.c

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/*
 * drivers/net/phy/national.c
 *
 * Driver for National Semiconductor PHYs
 *
 * Author: Stuart Menefy <[email protected]>
 * Maintainer: Giuseppe Cavallaro <[email protected]>
 *
 * Copyright (c) 2008 STMicroelectronics Limited
 *
 * 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.
 *
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>
#include <linux/netdevice.h>

#define DEBUG

/* DP83865 phy identifier values */
#define DP83865_PHY_ID  0x20005c7a

#define DP83865_INT_STATUS  0x14
#define DP83865_INT_MASK    0x15
#define DP83865_INT_CLEAR   0x17

#define DP83865_INT_REMOTE_FAULT 0x0008
#define DP83865_INT_ANE_COMPLETED 0x0010
#define DP83865_INT_LINK_CHANGE 0xe000
#define DP83865_INT_MASK_DEFAULT (DP83865_INT_REMOTE_FAULT | \
                DP83865_INT_ANE_COMPLETED | \
                DP83865_INT_LINK_CHANGE)

/* Advanced proprietary configuration */
#define NS_EXP_MEM_CTL  0x16
#define NS_EXP_MEM_DATA 0x1d
#define NS_EXP_MEM_ADD  0x1e

#define LED_CTRL_REG 0x13
#define AN_FALLBACK_AN 0x0001
#define AN_FALLBACK_CRC 0x0002
#define AN_FALLBACK_IE 0x0004
#define ALL_FALLBACK_ON (AN_FALLBACK_AN |  AN_FALLBACK_CRC | AN_FALLBACK_IE)

enum hdx_loopback {
    hdx_loopback_on = 0,
    hdx_loopback_off = 1,
};

static u8 ns_exp_read(struct phy_device *phydev, u16 reg)
{
    phy_write(phydev, NS_EXP_MEM_ADD, reg);
    return phy_read(phydev, NS_EXP_MEM_DATA);
}

static void ns_exp_write(struct phy_device *phydev, u16 reg, u8 data)
{
    phy_write(phydev, NS_EXP_MEM_ADD, reg);
    phy_write(phydev, NS_EXP_MEM_DATA, data);
}

static int ns_config_intr(struct phy_device *phydev)
{
    int err;

    if (phydev->interrupts == PHY_INTERRUPT_ENABLED)
        err = phy_write(phydev, DP83865_INT_MASK,
                DP83865_INT_MASK_DEFAULT);
    else
        err = phy_write(phydev, DP83865_INT_MASK, 0);

    return err;
}

static int ns_ack_interrupt(struct phy_device *phydev)
{
    int ret = phy_read(phydev, DP83865_INT_STATUS);
    if (ret < 0)
        return ret;

    /* Clear the interrupt status bit by writing a “1”
     * to the corresponding bit in INT_CLEAR (2:0 are reserved) */
    ret = phy_write(phydev, DP83865_INT_CLEAR, ret & ~0x7);

    return ret;
}

static void ns_giga_speed_fallback(struct phy_device *phydev, int mode)
{
    int bmcr = phy_read(phydev, MII_BMCR);

    phy_write(phydev, MII_BMCR, (bmcr | BMCR_PDOWN));

    /* Enable 8 bit expended memory read/write (no auto increment) */
    phy_write(phydev, NS_EXP_MEM_CTL, 0);
    phy_write(phydev, NS_EXP_MEM_ADD, 0x1C0);
    phy_write(phydev, NS_EXP_MEM_DATA, 0x0008);
    phy_write(phydev, MII_BMCR, (bmcr & ~BMCR_PDOWN));
    phy_write(phydev, LED_CTRL_REG, mode);
}

static void ns_10_base_t_hdx_loopack(struct phy_device *phydev, int disable)
{
    if (disable)
        ns_exp_write(phydev, 0x1c0, ns_exp_read(phydev, 0x1c0) | 1);
    else
        ns_exp_write(phydev, 0x1c0,
                 ns_exp_read(phydev, 0x1c0) & 0xfffe);

    pr_debug("10BASE-T HDX loopback %s\n",
         (ns_exp_read(phydev, 0x1c0) & 0x0001) ? "off" : "on");
}

static int ns_config_init(struct phy_device *phydev)
{
    ns_giga_speed_fallback(phydev, ALL_FALLBACK_ON);
    /* In the latest MAC or switches design, the 10 Mbps loopback
       is desired to be turned off. */
    ns_10_base_t_hdx_loopack(phydev, hdx_loopback_off);
    return ns_ack_interrupt(phydev);
}

static struct phy_driver dp83865_driver = {
    .phy_id = DP83865_PHY_ID,
    .phy_id_mask = 0xfffffff0,
    .name = "NatSemi DP83865",
    .features = PHY_GBIT_FEATURES | SUPPORTED_Pause | SUPPORTED_Asym_Pause,
    .flags = PHY_HAS_INTERRUPT,
    .config_init = ns_config_init,
    .config_aneg = genphy_config_aneg,
    .read_status = genphy_read_status,
    .ack_interrupt = ns_ack_interrupt,
    .config_intr = ns_config_intr,
    .driver = {.owner = THIS_MODULE,}
};

static int __init ns_init(void)
{
    return phy_driver_register(&dp83865_driver);
}

static void __exit ns_exit(void)
{
    phy_driver_unregister(&dp83865_driver);
}

MODULE_DESCRIPTION("NatSemi PHY driver");
MODULE_AUTHOR("Stuart Menefy");
MODULE_LICENSE("GPL");

module_init(ns_init);
module_exit(ns_exit);

static struct mdio_device_id __maybe_unused ns_tbl[] = {
    { DP83865_PHY_ID, 0xfffffff0 },
    { }
};

MODULE_DEVICE_TABLE(mdio, ns_tbl);