/*
 * Linux ARCnet driver - "RIM I" (entirely mem-mapped) cards
 *
 * 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/bootmem.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/io.h>

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

/* Internal function declarations */

static int arcrimi_probe(struct net_device *dev);
static int arcrimi_found(struct net_device *dev);
static void arcrimi_command(struct net_device *dev, int command);
static int arcrimi_status(struct net_device *dev);
static void arcrimi_setmask(struct net_device *dev, int mask);
static int arcrimi_reset(struct net_device *dev, int really_reset);
static void arcrimi_copy_to_card(struct net_device *dev, int bufnum, int offset,
                                 void *buf, int count);
static void arcrimi_copy_from_card(struct net_device *dev, int bufnum,
                                   int offset, void *buf, int count);

/* Handy defines for ARCnet specific stuff */

/* Amount of I/O memory used by the card */
#define BUFFER_SIZE     (512)
#define MIRROR_SIZE     (BUFFER_SIZE * 4)

/* We cannot probe for a RIM I card; one reason is I don't know how to reset
 * them.  In fact, we can't even get their node ID automatically.  So, we
 * need to be passed a specific shmem address, IRQ, and node ID.
 */
static int __init arcrimi_probe(struct net_device *dev)
{
        if (BUGLVL(D_NORMAL)) {
                pr_info("%s\n", "RIM I (entirely mem-mapped) support");
                pr_info("E-mail me if you actually test the RIM I driver, please!\n");
                pr_info("Given: node %02Xh, shmem %lXh, irq %d\n",
                        dev->dev_addr[0], dev->mem_start, dev->irq);
        }

        if (dev->mem_start <= 0 || dev->irq <= 0) {
                if (BUGLVL(D_NORMAL))
                        pr_err("No autoprobe for RIM I; you must specify the shmem and irq!\n");
                return -ENODEV;
        }
        if (dev->dev_addr[0] == 0) {
                if (BUGLVL(D_NORMAL))
                        pr_err("You need to specify your card's station ID!\n");
                return -ENODEV;
        }
        /* Grab the memory region at mem_start for MIRROR_SIZE bytes.
         * Later in arcrimi_found() the real size will be determined
         * and this reserve will be released and the correct size
         * will be taken.
         */
        if (!request_mem_region(dev->mem_start, MIRROR_SIZE, "arcnet (90xx)")) {
                if (BUGLVL(D_NORMAL))
                        pr_notice("Card memory already allocated\n");
                return -ENODEV;
        }
        return arcrimi_found(dev);
}

static int check_mirror(unsigned long addr, size_t size)
{
        void __iomem *p;
        int res = -1;

        if (!request_mem_region(addr, size, "arcnet (90xx)"))
                return -1;

        p = ioremap(addr, size);
        if (p) {
                if (arcnet_readb(p, COM9026_REG_R_STATUS) == TESTvalue)
                        res = 1;
                else
                        res = 0;
                iounmap(p);
        }

        release_mem_region(addr, size);
        return res;
}

/* Set up the struct net_device associated with this card.
 * Called after probing succeeds.
 */
static int __init arcrimi_found(struct net_device *dev)
{
        struct arcnet_local *lp;
        unsigned long first_mirror, last_mirror, shmem;
        void __iomem *p;
        int mirror_size;
        int err;

        p = ioremap(dev->mem_start, MIRROR_SIZE);
        if (!p) {
                release_mem_region(dev->mem_start, MIRROR_SIZE);
                arc_printk(D_NORMAL, dev, "Can't ioremap\n");
                return -ENODEV;
        }

        /* reserve the irq */
        if (request_irq(dev->irq, arcnet_interrupt, 0, "arcnet (RIM I)", dev)) {
                iounmap(p);
                release_mem_region(dev->mem_start, MIRROR_SIZE);
                arc_printk(D_NORMAL, dev, "Can't get IRQ %d!\n", dev->irq);
                return -ENODEV;
        }

        shmem = dev->mem_start;
        arcnet_writeb(TESTvalue, p, COM9026_REG_W_INTMASK);
        arcnet_writeb(TESTvalue, p, COM9026_REG_W_COMMAND);
                                        /* actually the station/node ID */

        /* find the real shared memory start/end points, including mirrors */

        /* guess the actual size of one "memory mirror" - the number of
         * bytes between copies of the shared memory.  On most cards, it's
         * 2k (or there are no mirrors at all) but on some, it's 4k.
         */
        mirror_size = MIRROR_SIZE;
        if (arcnet_readb(p, COM9026_REG_R_STATUS) == TESTvalue &&
            check_mirror(shmem - MIRROR_SIZE, MIRROR_SIZE) == 0 &&
            check_mirror(shmem - 2 * MIRROR_SIZE, MIRROR_SIZE) == 1)
                mirror_size = 2 * MIRROR_SIZE;

        first_mirror = shmem - mirror_size;
        while (check_mirror(first_mirror, mirror_size) == 1)
                first_mirror -= mirror_size;
        first_mirror += mirror_size;

        last_mirror = shmem + mirror_size;
        while (check_mirror(last_mirror, mirror_size) == 1)
                last_mirror += mirror_size;
        last_mirror -= mirror_size;

        dev->mem_start = first_mirror;
        dev->mem_end = last_mirror + MIRROR_SIZE - 1;

        /* initialize the rest of the device structure. */

        lp = netdev_priv(dev);
        lp->card_name = "RIM I";
        lp->hw.command = arcrimi_command;
        lp->hw.status = arcrimi_status;
        lp->hw.intmask = arcrimi_setmask;
        lp->hw.reset = arcrimi_reset;
        lp->hw.owner = THIS_MODULE;
        lp->hw.copy_to_card = arcrimi_copy_to_card;
        lp->hw.copy_from_card = arcrimi_copy_from_card;

        /* re-reserve the memory region - arcrimi_probe() alloced this reqion
         * but didn't know the real size.  Free that region and then re-get
         * with the correct size.  There is a VERY slim chance this could
         * fail.
         */
        iounmap(p);
        release_mem_region(shmem, MIRROR_SIZE);
        if (!request_mem_region(dev->mem_start,
                                dev->mem_end - dev->mem_start + 1,
                                "arcnet (90xx)")) {
                arc_printk(D_NORMAL, dev, "Card memory already allocated\n");
                goto err_free_irq;
        }

        lp->mem_start = ioremap(dev->mem_start,
                                dev->mem_end - dev->mem_start + 1);
        if (!lp->mem_start) {
                arc_printk(D_NORMAL, dev, "Can't remap device memory!\n");
                goto err_release_mem;
        }

        /* get and check the station ID from offset 1 in shmem */
        dev->dev_addr[0] = arcnet_readb(lp->mem_start, COM9026_REG_R_STATION);

        arc_printk(D_NORMAL, dev, "ARCnet RIM I: station %02Xh found at IRQ %d, ShMem %lXh (%ld*%d bytes)\n",
                   dev->dev_addr[0],
                   dev->irq, dev->mem_start,
                   (dev->mem_end - dev->mem_start + 1) / mirror_size,
                   mirror_size);

        err = register_netdev(dev);
        if (err)
                goto err_unmap;

        return 0;

err_unmap:
        iounmap(lp->mem_start);
err_release_mem:
        release_mem_region(dev->mem_start, dev->mem_end - dev->mem_start + 1);
err_free_irq:
        free_irq(dev->irq, dev);
        return -EIO;
}

/* 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 arcrimi_reset(struct net_device *dev, int really_reset)
{
        struct arcnet_local *lp = netdev_priv(dev);
        void __iomem *ioaddr = lp->mem_start + 0x800;

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

        if (really_reset) {
                arcnet_writeb(TESTvalue, ioaddr, -0x800);       /* fake reset */
                return 0;
        }
        /* clear flags & end reset */
        arcnet_writeb(CFLAGScmd | RESETclear, ioaddr, COM9026_REG_W_COMMAND);
        arcnet_writeb(CFLAGScmd | CONFIGclear, ioaddr, COM9026_REG_W_COMMAND);

        /* enable extended (512-byte) packets */
        arcnet_writeb(CONFIGcmd | EXTconf, ioaddr, COM9026_REG_W_COMMAND);

        /* done!  return success. */
        return 0;
}

static void arcrimi_setmask(struct net_device *dev, int mask)
{
        struct arcnet_local *lp = netdev_priv(dev);
        void __iomem *ioaddr = lp->mem_start + 0x800;

        arcnet_writeb(mask, ioaddr, COM9026_REG_W_INTMASK);
}

static int arcrimi_status(struct net_device *dev)
{
        struct arcnet_local *lp = netdev_priv(dev);
        void __iomem *ioaddr = lp->mem_start + 0x800;

        return arcnet_readb(ioaddr, COM9026_REG_R_STATUS);
}

static void arcrimi_command(struct net_device *dev, int cmd)
{
        struct arcnet_local *lp = netdev_priv(dev);
        void __iomem *ioaddr = lp->mem_start + 0x800;

        arcnet_writeb(cmd, ioaddr, COM9026_REG_W_COMMAND);
}

static void arcrimi_copy_to_card(struct net_device *dev, int bufnum, int offset,
                                 void *buf, int count)
{
        struct arcnet_local *lp = netdev_priv(dev);
        void __iomem *memaddr = lp->mem_start + 0x800 + bufnum * 512 + offset;

        TIME(dev, "memcpy_toio", count, memcpy_toio(memaddr, buf, count));
}

static void arcrimi_copy_from_card(struct net_device *dev, int bufnum,
                                   int offset, void *buf, int count)
{
        struct arcnet_local *lp = netdev_priv(dev);
        void __iomem *memaddr = lp->mem_start + 0x800 + bufnum * 512 + offset;

        TIME(dev, "memcpy_fromio", count, memcpy_fromio(buf, memaddr, count));
}

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

module_param(node, int, 0);
module_param(io, int, 0);
module_param(irq, int, 0);
module_param_string(device, device, sizeof(device), 0);
MODULE_LICENSE("GPL");

static struct net_device *my_dev;

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

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

        if (node && node != 0xff)
                dev->dev_addr[0] = node;

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

        if (arcrimi_probe(dev)) {
                free_netdev(dev);
                return -EIO;
        }

        my_dev = dev;
        return 0;
}

static void __exit arc_rimi_exit(void)
{
        struct net_device *dev = my_dev;
        struct arcnet_local *lp = netdev_priv(dev);

        unregister_netdev(dev);
        iounmap(lp->mem_start);
        release_mem_region(dev->mem_start, dev->mem_end - dev->mem_start + 1);
        free_irq(dev->irq, dev);
        free_netdev(dev);
}

#ifndef MODULE
static int __init arcrimi_setup(char *s)
{
        int ints[8];

        s = get_options(s, 8, ints);
        if (!ints[0])
                return 1;
        switch (ints[0]) {
        default:                /* ERROR */
                pr_err("Too many arguments\n");
        case 3:         /* Node ID */
                node = ints[3];
        case 2:         /* IRQ */
                irq = ints[2];
        case 1:         /* IO address */
                io = ints[1];
        }
        if (*s)
                snprintf(device, sizeof(device), "%s", s);
        return 1;
}
__setup("arcrimi=", arcrimi_setup);
#endif                          /* MODULE */

module_init(arc_rimi_init)
module_exit(arc_rimi_exit)