/*
 * Linux ARCnet driver - COM90xx chipset (IO-mapped buffers)
 *
 * Written 1997 by David Woodhouse.
 * Written 1994-1999 by Avery Pennarun.
 * Written 1999-2000 by Martin Mares <mj@ucw.cz>.
 * Derived from skeleton.c by Donald Becker.
 *
 * Special thanks to Contemporary Controls, Inc. (www.ccontrols.com)
 *  for sponsoring the further development of this driver.
 *
 * **********************
 *
 * The original copyright of skeleton.c was as follows:
 *
 * skeleton.c Written 1993 by Donald Becker.
 * Copyright 1993 United States Government as represented by the
 * Director, National Security Agency.  This software may only be used
 * and distributed according to the terms of the GNU General Public License as
 * modified by SRC, incorporated herein by reference.
 *
 * **********************
 *
 * For more details, see drivers/net/arcnet.c
 *
 * **********************
 */

#define pr_fmt(fmt) "arcnet:" KBUILD_MODNAME ": " fmt

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/memblock.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>

#include "arcdevice.h"
#include "com9026.h"

/* Internal function declarations */

static int com90io_found(struct net_device *dev);
static void com90io_command(struct net_device *dev, int command);
static int com90io_status(struct net_device *dev);
static void com90io_setmask(struct net_device *dev, int mask);
static int com90io_reset(struct net_device *dev, int really_reset);
static void com90io_copy_to_card(struct net_device *dev, int bufnum, int offset,
                                 void *buf, int count);
static void com90io_copy_from_card(struct net_device *dev, int bufnum,
                                   int offset, void *buf, int count);

/* Handy defines for ARCnet specific stuff */

/* The number of low I/O ports used by the card. */
#define ARCNET_TOTAL_SIZE 16

/****************************************************************************
 *                                                                          *
 * IO-mapped operation routines                                             *
 *                                                                          *
 ****************************************************************************/

#undef ONE_AT_A_TIME_TX
#undef ONE_AT_A_TIME_RX

static u_char get_buffer_byte(struct net_device *dev, unsigned offset)
{
        int ioaddr = dev->base_addr;

        arcnet_outb(offset >> 8, ioaddr, COM9026_REG_W_ADDR_HI);
        arcnet_outb(offset & 0xff, ioaddr, COM9026_REG_W_ADDR_LO);

        return arcnet_inb(ioaddr, COM9026_REG_RW_MEMDATA);
}

#ifdef ONE_AT_A_TIME_TX
static void put_buffer_byte(struct net_device *dev, unsigned offset,
                            u_char datum)
{
        int ioaddr = dev->base_addr;

        arcnet_outb(offset >> 8, ioaddr, COM9026_REG_W_ADDR_HI);
        arcnet_outb(offset & 0xff, ioaddr, COM9026_REG_W_ADDR_LO);

        arcnet_outb(datum, ioaddr, COM9026_REG_RW_MEMDATA);
}

#endif

static void get_whole_buffer(struct net_device *dev, unsigned offset,
                             unsigned length, char *dest)
{
        int ioaddr = dev->base_addr;

        arcnet_outb((offset >> 8) | AUTOINCflag, ioaddr, COM9026_REG_W_ADDR_HI);
        arcnet_outb(offset & 0xff, ioaddr, COM9026_REG_W_ADDR_LO);

        while (length--)
#ifdef ONE_AT_A_TIME_RX
                *(dest++) = get_buffer_byte(dev, offset++);
#else
                *(dest++) = arcnet_inb(ioaddr, COM9026_REG_RW_MEMDATA);
#endif
}

static void put_whole_buffer(struct net_device *dev, unsigned offset,
                             unsigned length, char *dest)
{
        int ioaddr = dev->base_addr;

        arcnet_outb((offset >> 8) | AUTOINCflag, ioaddr, COM9026_REG_W_ADDR_HI);
        arcnet_outb(offset & 0xff, ioaddr,COM9026_REG_W_ADDR_LO);

        while (length--)
#ifdef ONE_AT_A_TIME_TX
                put_buffer_byte(dev, offset++, *(dest++));
#else
                arcnet_outb(*(dest++), ioaddr, COM9026_REG_RW_MEMDATA);
#endif
}

/* We cannot probe for an IO mapped card either, although we can check that
 * it's where we were told it was, and even autoirq
 */
static int __init com90io_probe(struct net_device *dev)
{
        int ioaddr = dev->base_addr, status;
        unsigned long airqmask;

        if (BUGLVL(D_NORMAL)) {
                pr_info("%s\n", "COM90xx IO-mapped mode support (by David Woodhouse et el.)");
                pr_info("E-mail me if you actually test this driver, please!\n");
        }

        if (!ioaddr) {
                arc_printk(D_NORMAL, dev, "No autoprobe for IO mapped cards; you must specify the base address!\n");
                return -ENODEV;
        }
        if (!request_region(ioaddr, ARCNET_TOTAL_SIZE, "com90io probe")) {
                arc_printk(D_INIT_REASONS, dev, "IO request_region %x-%x failed\n",
                           ioaddr, ioaddr + ARCNET_TOTAL_SIZE - 1);
                return -ENXIO;
        }
        if (arcnet_inb(ioaddr, COM9026_REG_R_STATUS) == 0xFF) {
                arc_printk(D_INIT_REASONS, dev, "IO address %x empty\n",
                           ioaddr);
                goto err_out;
        }
        arcnet_inb(ioaddr, COM9026_REG_R_RESET);
        mdelay(RESETtime);

        status = arcnet_inb(ioaddr, COM9026_REG_R_STATUS);

        if ((status & 0x9D) != (NORXflag | RECONflag | TXFREEflag | RESETflag)) {
                arc_printk(D_INIT_REASONS, dev, "Status invalid (%Xh)\n",
                           status);
                goto err_out;
        }
        arc_printk(D_INIT_REASONS, dev, "Status after reset: %X\n", status);

        arcnet_outb(CFLAGScmd | RESETclear | CONFIGclear,
                    ioaddr, COM9026_REG_W_COMMAND);

        arc_printk(D_INIT_REASONS, dev, "Status after reset acknowledged: %X\n",
                   status);

        status = arcnet_inb(ioaddr, COM9026_REG_R_STATUS);

        if (status & RESETflag) {
                arc_printk(D_INIT_REASONS, dev, "Eternal reset (status=%Xh)\n",
                           status);
                goto err_out;
        }
        arcnet_outb((0x16 | IOMAPflag) & ~ENABLE16flag,
                    ioaddr, COM9026_REG_RW_CONFIG);

        /* Read first loc'n of memory */

        arcnet_outb(AUTOINCflag, ioaddr, COM9026_REG_W_ADDR_HI);
        arcnet_outb(0, ioaddr,  COM9026_REG_W_ADDR_LO);

        status = arcnet_inb(ioaddr, COM9026_REG_RW_MEMDATA);
        if (status != 0xd1) {
                arc_printk(D_INIT_REASONS, dev, "Signature byte not found (%Xh instead).\n",
                           status);
                goto err_out;
        }
        if (!dev->irq) {
                /* if we do this, we're sure to get an IRQ since the
                 * card has just reset and the NORXflag is on until
                 * we tell it to start receiving.
                 */

                airqmask = probe_irq_on();
                arcnet_outb(NORXflag, ioaddr, COM9026_REG_W_INTMASK);
                udelay(1);
                arcnet_outb(0, ioaddr, COM9026_REG_W_INTMASK);
                dev->irq = probe_irq_off(airqmask);

                if ((int)dev->irq <= 0) {
                        arc_printk(D_INIT_REASONS, dev, "Autoprobe IRQ failed\n");
                        goto err_out;
                }
        }
        release_region(ioaddr, ARCNET_TOTAL_SIZE); /* end of probing */
        return com90io_found(dev);

err_out:
        release_region(ioaddr, ARCNET_TOTAL_SIZE);
        return -ENODEV;
}

/* Set up the struct net_device associated with this card.  Called after
 * probing succeeds.
 */
static int __init com90io_found(struct net_device *dev)
{
        struct arcnet_local *lp;
        int ioaddr = dev->base_addr;
        int err;

        /* Reserve the irq */
        if (request_irq(dev->irq, arcnet_interrupt, 0,
                        "arcnet (COM90xx-IO)", dev)) {
                arc_printk(D_NORMAL, dev, "Can't get IRQ %d!\n", dev->irq);
                return -ENODEV;
        }
        /* Reserve the I/O region */
        if (!request_region(dev->base_addr, ARCNET_TOTAL_SIZE,
                            "arcnet (COM90xx-IO)")) {
                free_irq(dev->irq, dev);
                return -EBUSY;
        }

        lp = netdev_priv(dev);
        lp->card_name = "COM90xx I/O";
        lp->hw.command = com90io_command;
        lp->hw.status = com90io_status;
        lp->hw.intmask = com90io_setmask;
        lp->hw.reset = com90io_reset;
        lp->hw.owner = THIS_MODULE;
        lp->hw.copy_to_card = com90io_copy_to_card;
        lp->hw.copy_from_card = com90io_copy_from_card;

        lp->config = (0x16 | IOMAPflag) & ~ENABLE16flag;
        arcnet_outb(lp->config, ioaddr, COM9026_REG_RW_CONFIG);

        /* get and check the station ID from offset 1 in shmem */

        arcnet_set_addr(dev, get_buffer_byte(dev, 1));

        err = register_netdev(dev);
        if (err) {
                arcnet_outb(arcnet_inb(ioaddr, COM9026_REG_RW_CONFIG) & ~IOMAPflag,
                            ioaddr, COM9026_REG_RW_CONFIG);
                free_irq(dev->irq, dev);
                release_region(dev->base_addr, ARCNET_TOTAL_SIZE);
                return err;
        }

        arc_printk(D_NORMAL, dev, "COM90IO: station %02Xh found at %03lXh, IRQ %d.\n",
                   dev->dev_addr[0], dev->base_addr, dev->irq);

        return 0;
}

/* Do a hardware reset on the card, and set up necessary registers.
 *
 * This should be called as little as possible, because it disrupts the
 * token on the network (causes a RECON) and requires a significant delay.
 *
 * However, it does make sure the card is in a defined state.
 */
static int com90io_reset(struct net_device *dev, int really_reset)
{
        struct arcnet_local *lp = netdev_priv(dev);
        short ioaddr = dev->base_addr;

        arc_printk(D_INIT, dev, "Resetting %s (status=%02Xh)\n",
                   dev->name, arcnet_inb(ioaddr, COM9026_REG_R_STATUS));

        if (really_reset) {
                /* reset the card */
                arcnet_inb(ioaddr, COM9026_REG_R_RESET);
                mdelay(RESETtime);
        }
        /* Set the thing to IO-mapped, 8-bit  mode */
        lp->config = (0x1C | IOMAPflag) & ~ENABLE16flag;
        arcnet_outb(lp->config, ioaddr, COM9026_REG_RW_CONFIG);

        arcnet_outb(CFLAGScmd | RESETclear, ioaddr, COM9026_REG_W_COMMAND);
                                        /* clear flags & end reset */
        arcnet_outb(CFLAGScmd | CONFIGclear, ioaddr, COM9026_REG_W_COMMAND);

        /* verify that the ARCnet signature byte is present */
        if (get_buffer_byte(dev, 0) != TESTvalue) {
                arc_printk(D_NORMAL, dev, "reset failed: TESTvalue not present.\n");
                return 1;
        }
        /* enable extended (512-byte) packets */
        arcnet_outb(CONFIGcmd | EXTconf, ioaddr, COM9026_REG_W_COMMAND);
        /* done!  return success. */
        return 0;
}

static void com90io_command(struct net_device *dev, int cmd)
{
        short ioaddr = dev->base_addr;

        arcnet_outb(cmd, ioaddr, COM9026_REG_W_COMMAND);
}

static int com90io_status(struct net_device *dev)
{
        short ioaddr = dev->base_addr;

        return arcnet_inb(ioaddr, COM9026_REG_R_STATUS);
}

static void com90io_setmask(struct net_device *dev, int mask)
{
        short ioaddr = dev->base_addr;

        arcnet_outb(mask, ioaddr, COM9026_REG_W_INTMASK);
}

static void com90io_copy_to_card(struct net_device *dev, int bufnum,
                                 int offset, void *buf, int count)
{
        TIME(dev, "put_whole_buffer", count,
             put_whole_buffer(dev, bufnum * 512 + offset, count, buf));
}

static void com90io_copy_from_card(struct net_device *dev, int bufnum,
                                   int offset, void *buf, int count)
{
        TIME(dev, "get_whole_buffer", count,
             get_whole_buffer(dev, bufnum * 512 + offset, count, buf));
}

static int io;                  /* use the insmod io= irq= shmem= options */
static int irq;
static char device[9];          /* use eg. device=arc1 to change name */

module_param_hw(io, int, ioport, 0);
module_param_hw(irq, int, irq, 0);
module_param_string(device, device, sizeof(device), 0);
MODULE_DESCRIPTION("ARCnet COM90xx IO mapped chipset driver");
MODULE_LICENSE("GPL");

#ifndef MODULE
static int __init com90io_setup(char *s)
{
        int ints[4];

        s = get_options(s, 4, ints);
        if (!ints[0])
                return 0;
        switch (ints[0]) {
        default:                /* ERROR */
                pr_err("Too many arguments\n");
                fallthrough;
        case 2:         /* IRQ */
                irq = ints[2];
                fallthrough;
        case 1:         /* IO address */
                io = ints[1];
        }
        if (*s)
                snprintf(device, sizeof(device), "%s", s);
        return 1;
}
__setup("com90io=", com90io_setup);
#endif

static struct net_device *my_dev;

static int __init com90io_init(void)
{
        struct net_device *dev;
        int err;

        dev = alloc_arcdev(device);
        if (!dev)
                return -ENOMEM;

        dev->base_addr = io;
        dev->irq = irq;
        if (dev->irq == 2)
                dev->irq = 9;

        err = com90io_probe(dev);

        if (err) {
                free_arcdev(dev);
                return err;
        }

        my_dev = dev;
        return 0;
}

static void __exit com90io_exit(void)
{
        struct net_device *dev = my_dev;
        int ioaddr = dev->base_addr;

        unregister_netdev(dev);

        /* In case the old driver is loaded later,
         * set the thing back to MMAP mode
         */
        arcnet_outb(arcnet_inb(ioaddr, COM9026_REG_RW_CONFIG) & ~IOMAPflag,
                    ioaddr, COM9026_REG_RW_CONFIG);

        free_irq(dev->irq, dev);
        release_region(dev->base_addr, ARCNET_TOTAL_SIZE);
        free_arcdev(dev);
}

module_init(com90io_init)
module_exit(com90io_exit)