// SPDX-License-Identifier: GPL-2.0+
/*
 * drivers/net/phy/cicada.c
 *
 * Driver for Cicada PHYs
 *
 * Author: Andy Fleming
 *
 * Copyright (c) 2004 Freescale Semiconductor, Inc.
 */
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/unistd.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/spinlock.h>
#include <linux/mm.h>
#include <linux/module.h>
#include <linux/mii.h>
#include <linux/ethtool.h>
#include <linux/phy.h>

#include <linux/io.h>
#include <asm/irq.h>
#include <linux/uaccess.h>

/* Cicada Extended Control Register 1 */
#define MII_CIS8201_EXT_CON1           0x17
#define MII_CIS8201_EXTCON1_INIT       0x0000

/* Cicada Interrupt Mask Register */
#define MII_CIS8201_IMASK               0x19
#define MII_CIS8201_IMASK_IEN           0x8000
#define MII_CIS8201_IMASK_SPEED 0x4000
#define MII_CIS8201_IMASK_LINK          0x2000
#define MII_CIS8201_IMASK_DUPLEX        0x1000
#define MII_CIS8201_IMASK_MASK          0xf000

/* Cicada Interrupt Status Register */
#define MII_CIS8201_ISTAT               0x1a
#define MII_CIS8201_ISTAT_STATUS        0x8000
#define MII_CIS8201_ISTAT_SPEED 0x4000
#define MII_CIS8201_ISTAT_LINK          0x2000
#define MII_CIS8201_ISTAT_DUPLEX        0x1000

/* Cicada Auxiliary Control/Status Register */
#define MII_CIS8201_AUX_CONSTAT        0x1c
#define MII_CIS8201_AUXCONSTAT_INIT    0x0004
#define MII_CIS8201_AUXCONSTAT_DUPLEX  0x0020
#define MII_CIS8201_AUXCONSTAT_SPEED   0x0018
#define MII_CIS8201_AUXCONSTAT_GBIT    0x0010
#define MII_CIS8201_AUXCONSTAT_100     0x0008

MODULE_DESCRIPTION("Cicadia PHY driver");
MODULE_AUTHOR("Andy Fleming");
MODULE_LICENSE("GPL");

static int cis820x_config_init(struct phy_device *phydev)
{
        int err;

        err = phy_write(phydev, MII_CIS8201_AUX_CONSTAT,
                        MII_CIS8201_AUXCONSTAT_INIT);

        if (err < 0)
                return err;

        err = phy_write(phydev, MII_CIS8201_EXT_CON1,
                        MII_CIS8201_EXTCON1_INIT);

        return err;
}

static int cis820x_ack_interrupt(struct phy_device *phydev)
{
        int err = phy_read(phydev, MII_CIS8201_ISTAT);

        return (err < 0) ? err : 0;
}

static int cis820x_config_intr(struct phy_device *phydev)
{
        int err;

        if (phydev->interrupts == PHY_INTERRUPT_ENABLED) {
                err = cis820x_ack_interrupt(phydev);
                if (err)
                        return err;

                err = phy_write(phydev, MII_CIS8201_IMASK,
                                MII_CIS8201_IMASK_MASK);
        } else {
                err = phy_write(phydev, MII_CIS8201_IMASK, 0);
                if (err)
                        return err;

                err = cis820x_ack_interrupt(phydev);
        }

        return err;
}

static irqreturn_t cis820x_handle_interrupt(struct phy_device *phydev)
{
        int irq_status;

        irq_status = phy_read(phydev, MII_CIS8201_ISTAT);
        if (irq_status < 0) {
                phy_error(phydev);
                return IRQ_NONE;
        }

        if (!(irq_status & MII_CIS8201_IMASK_MASK))
                return IRQ_NONE;

        phy_trigger_machine(phydev);

        return IRQ_HANDLED;
}

/* Cicada 8201, a.k.a Vitesse VSC8201 */
static struct phy_driver cis820x_driver[] = {
{
        .phy_id         = 0x000fc410,
        .name           = "Cicada Cis8201",
        .phy_id_mask    = 0x000ffff0,
        /* PHY_GBIT_FEATURES */
        .config_init    = &cis820x_config_init,
        .config_intr    = &cis820x_config_intr,
        .handle_interrupt = &cis820x_handle_interrupt,
}, {
        .phy_id         = 0x000fc440,
        .name           = "Cicada Cis8204",
        .phy_id_mask    = 0x000fffc0,
        /* PHY_GBIT_FEATURES */
        .config_init    = &cis820x_config_init,
        .config_intr    = &cis820x_config_intr,
        .handle_interrupt = &cis820x_handle_interrupt,
} };

module_phy_driver(cis820x_driver);

static const struct mdio_device_id __maybe_unused cicada_tbl[] = {
        { 0x000fc410, 0x000ffff0 },
        { 0x000fc440, 0x000fffc0 },
        { }
};

MODULE_DEVICE_TABLE(mdio, cicada_tbl);