/*
 * Linux ARCnet driver - COM90xx chipset (memory-mapped buffers)
 *
 * Written 1994-1999 by Avery Pennarun.
 * Written 1999 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/module.h>
#include <linux/moduleparam.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <linux/ioport.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/slab.h>
#include <linux/io.h>

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

/* Define this to speed up the autoprobe by assuming if only one io port and
 * shmem are left in the list at Stage 5, they must correspond to each
 * other.
 *
 * This is undefined by default because it might not always be true, and the
 * extra check makes the autoprobe even more careful.  Speed demons can turn
 * it on - I think it should be fine if you only have one ARCnet card
 * installed.
 *
 * If no ARCnet cards are installed, this delay never happens anyway and thus
 * the option has no effect.
 */
#undef FAST_PROBE

/* Internal function declarations */
static int com90xx_found(int ioaddr, int airq, u_long shmem, void __iomem *);
static void com90xx_command(struct net_device *dev, int command);
static int com90xx_status(struct net_device *dev);
static void com90xx_setmask(struct net_device *dev, int mask);
static int com90xx_reset(struct net_device *dev, int really_reset);
static void com90xx_copy_to_card(struct net_device *dev, int bufnum, int offset,
                                 void *buf, int count);
static void com90xx_copy_from_card(struct net_device *dev, int bufnum,
                                   int offset, void *buf, int count);

/* Known ARCnet cards */

static struct net_device *cards[16];
static int numcards;

/* Handy defines for ARCnet specific stuff */

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

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

static int com90xx_skip_probe __initdata = 0;

/* Module parameters */

static int io;                  /* use the insmod io= irq= shmem= options */
static int irq;
static int shmem;
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(shmem, int, 0);
module_param_string(device, device, sizeof(device), 0);

static void __init com90xx_probe(void)
{
        int count, status, ioaddr, numprint, airq, openparen = 0;
        unsigned long airqmask;
        int ports[(0x3f0 - 0x200) / 16 + 1] = { 0 };
        unsigned long *shmems;
        void __iomem **iomem;
        int numports, numshmems, *port;
        u_long *p;
        int index;

        if (!io && !irq && !shmem && !*device && com90xx_skip_probe)
                return;

        shmems = kzalloc(((0x100000 - 0xa0000) / 0x800) * sizeof(unsigned long),
                         GFP_KERNEL);
        if (!shmems)
                return;
        iomem = kzalloc(((0x100000 - 0xa0000) / 0x800) * sizeof(void __iomem *),
                        GFP_KERNEL);
        if (!iomem) {
                kfree(shmems);
                return;
        }

        if (BUGLVL(D_NORMAL))
                pr_info("%s\n", "COM90xx chipset support");

        /* set up the arrays where we'll store the possible probe addresses */
        numports = numshmems = 0;
        if (io)
                ports[numports++] = io;
        else
                for (count = 0x200; count <= 0x3f0; count += 16)
                        ports[numports++] = count;
        if (shmem)
                shmems[numshmems++] = shmem;
        else
                for (count = 0xA0000; count <= 0xFF800; count += 2048)
                        shmems[numshmems++] = count;

        /* Stage 1: abandon any reserved ports, or ones with status==0xFF
         * (empty), and reset any others by reading the reset port.
         */
        numprint = -1;
        for (port = &ports[0]; port - ports < numports; port++) {
                numprint++;
                numprint %= 8;
                if (!numprint) {
                        arc_cont(D_INIT, "\n");
                        arc_cont(D_INIT, "S1: ");
                }
                arc_cont(D_INIT, "%Xh ", *port);

                ioaddr = *port;

                if (!request_region(*port, ARCNET_TOTAL_SIZE,
                                    "arcnet (90xx)")) {
                        arc_cont(D_INIT_REASONS, "(request_region)\n");
                        arc_cont(D_INIT_REASONS, "S1: ");
                        if (BUGLVL(D_INIT_REASONS))
                                numprint = 0;
                        *port-- = ports[--numports];
                        continue;
                }
                if (arcnet_inb(ioaddr, COM9026_REG_R_STATUS) == 0xFF) {
                        arc_cont(D_INIT_REASONS, "(empty)\n");
                        arc_cont(D_INIT_REASONS, "S1: ");
                        if (BUGLVL(D_INIT_REASONS))
                                numprint = 0;
                        release_region(*port, ARCNET_TOTAL_SIZE);
                        *port-- = ports[--numports];
                        continue;
                }
                /* begin resetting card */
                arcnet_inb(ioaddr, COM9026_REG_R_RESET);

                arc_cont(D_INIT_REASONS, "\n");
                arc_cont(D_INIT_REASONS, "S1: ");
                if (BUGLVL(D_INIT_REASONS))
                        numprint = 0;
        }
        arc_cont(D_INIT, "\n");

        if (!numports) {
                arc_cont(D_NORMAL, "S1: No ARCnet cards found.\n");
                kfree(shmems);
                kfree(iomem);
                return;
        }
        /* Stage 2: we have now reset any possible ARCnet cards, so we can't
         * do anything until they finish.  If D_INIT, print the list of
         * cards that are left.
         */
        numprint = -1;
        for (port = &ports[0]; port < ports + numports; port++) {
                numprint++;
                numprint %= 8;
                if (!numprint) {
                        arc_cont(D_INIT, "\n");
                        arc_cont(D_INIT, "S2: ");
                }
                arc_cont(D_INIT, "%Xh ", *port);
        }
        arc_cont(D_INIT, "\n");
        mdelay(RESETtime);

        /* Stage 3: abandon any shmem addresses that don't have the signature
         * 0xD1 byte in the right place, or are read-only.
         */
        numprint = -1;
        for (index = 0, p = &shmems[0]; index < numshmems; p++, index++) {
                void __iomem *base;

                numprint++;
                numprint %= 8;
                if (!numprint) {
                        arc_cont(D_INIT, "\n");
                        arc_cont(D_INIT, "S3: ");
                }
                arc_cont(D_INIT, "%lXh ", *p);

                if (!request_mem_region(*p, MIRROR_SIZE, "arcnet (90xx)")) {
                        arc_cont(D_INIT_REASONS, "(request_mem_region)\n");
                        arc_cont(D_INIT_REASONS, "Stage 3: ");
                        if (BUGLVL(D_INIT_REASONS))
                                numprint = 0;
                        goto out;
                }
                base = ioremap(*p, MIRROR_SIZE);
                if (!base) {
                        arc_cont(D_INIT_REASONS, "(ioremap)\n");
                        arc_cont(D_INIT_REASONS, "Stage 3: ");
                        if (BUGLVL(D_INIT_REASONS))
                                numprint = 0;
                        goto out1;
                }
                if (arcnet_readb(base, COM9026_REG_R_STATUS) != TESTvalue) {
                        arc_cont(D_INIT_REASONS, "(%02Xh != %02Xh)\n",
                                 arcnet_readb(base, COM9026_REG_R_STATUS),
                                 TESTvalue);
                        arc_cont(D_INIT_REASONS, "S3: ");
                        if (BUGLVL(D_INIT_REASONS))
                                numprint = 0;
                        goto out2;
                }
                /* By writing 0x42 to the TESTvalue location, we also make
                 * sure no "mirror" shmem areas show up - if they occur
                 * in another pass through this loop, they will be discarded
                 * because *cptr != TESTvalue.
                 */
                arcnet_writeb(0x42, base, COM9026_REG_W_INTMASK);
                if (arcnet_readb(base, COM9026_REG_R_STATUS) != 0x42) {
                        arc_cont(D_INIT_REASONS, "(read only)\n");
                        arc_cont(D_INIT_REASONS, "S3: ");
                        goto out2;
                }
                arc_cont(D_INIT_REASONS, "\n");
                arc_cont(D_INIT_REASONS, "S3: ");
                if (BUGLVL(D_INIT_REASONS))
                        numprint = 0;
                iomem[index] = base;
                continue;
        out2:
                iounmap(base);
        out1:
                release_mem_region(*p, MIRROR_SIZE);
        out:
                *p-- = shmems[--numshmems];
                index--;
        }
        arc_cont(D_INIT, "\n");

        if (!numshmems) {
                arc_cont(D_NORMAL, "S3: No ARCnet cards found.\n");
                for (port = &ports[0]; port < ports + numports; port++)
                        release_region(*port, ARCNET_TOTAL_SIZE);
                kfree(shmems);
                kfree(iomem);
                return;
        }
        /* Stage 4: something of a dummy, to report the shmems that are
         * still possible after stage 3.
         */
        numprint = -1;
        for (p = &shmems[0]; p < shmems + numshmems; p++) {
                numprint++;
                numprint %= 8;
                if (!numprint) {
                        arc_cont(D_INIT, "\n");
                        arc_cont(D_INIT, "S4: ");
                }
                arc_cont(D_INIT, "%lXh ", *p);
        }
        arc_cont(D_INIT, "\n");

        /* Stage 5: for any ports that have the correct status, can disable
         * the RESET flag, and (if no irq is given) generate an autoirq,
         * register an ARCnet device.
         *
         * Currently, we can only register one device per probe, so quit
         * after the first one is found.
         */
        numprint = -1;
        for (port = &ports[0]; port < ports + numports; port++) {
                int found = 0;

                numprint++;
                numprint %= 8;
                if (!numprint) {
                        arc_cont(D_INIT, "\n");
                        arc_cont(D_INIT, "S5: ");
                }
                arc_cont(D_INIT, "%Xh ", *port);

                ioaddr = *port;
                status = arcnet_inb(ioaddr, COM9026_REG_R_STATUS);

                if ((status & 0x9D)
                    != (NORXflag | RECONflag | TXFREEflag | RESETflag)) {
                        arc_cont(D_INIT_REASONS, "(status=%Xh)\n", status);
                        arc_cont(D_INIT_REASONS, "S5: ");
                        if (BUGLVL(D_INIT_REASONS))
                                numprint = 0;
                        release_region(*port, ARCNET_TOTAL_SIZE);
                        *port-- = ports[--numports];
                        continue;
                }
                arcnet_outb(CFLAGScmd | RESETclear | CONFIGclear,
                            ioaddr, COM9026_REG_W_COMMAND);
                status = arcnet_inb(ioaddr, COM9026_REG_R_STATUS);
                if (status & RESETflag) {
                        arc_cont(D_INIT_REASONS, " (eternal reset, status=%Xh)\n",
                                 status);
                        arc_cont(D_INIT_REASONS, "S5: ");
                        if (BUGLVL(D_INIT_REASONS))
                                numprint = 0;
                        release_region(*port, ARCNET_TOTAL_SIZE);
                        *port-- = ports[--numports];
                        continue;
                }
                /* skip this completely if an IRQ was given, because maybe
                 * we're on a machine that locks during autoirq!
                 */
                if (!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);
                        airq = probe_irq_off(airqmask);

                        if (airq <= 0) {
                                arc_cont(D_INIT_REASONS, "(airq=%d)\n", airq);
                                arc_cont(D_INIT_REASONS, "S5: ");
                                if (BUGLVL(D_INIT_REASONS))
                                        numprint = 0;
                                release_region(*port, ARCNET_TOTAL_SIZE);
                                *port-- = ports[--numports];
                                continue;
                        }
                } else {
                        airq = irq;
                }

                arc_cont(D_INIT, "(%d,", airq);
                openparen = 1;

                /* Everything seems okay.  But which shmem, if any, puts
                 * back its signature byte when the card is reset?
                 *
                 * If there are multiple cards installed, there might be
                 * multiple shmems still in the list.
                 */
#ifdef FAST_PROBE
                if (numports > 1 || numshmems > 1) {
                        arcnet_inb(ioaddr, COM9026_REG_R_RESET);
                        mdelay(RESETtime);
                } else {
                        /* just one shmem and port, assume they match */
                        arcnet_writeb(TESTvalue, iomem[0],
                                      COM9026_REG_W_INTMASK);
                }
#else
                arcnet_inb(ioaddr, COM9026_REG_R_RESET);
                mdelay(RESETtime);
#endif

                for (index = 0; index < numshmems; index++) {
                        u_long ptr = shmems[index];
                        void __iomem *base = iomem[index];

                        if (arcnet_readb(base, COM9026_REG_R_STATUS) == TESTvalue) {    /* found one */
                                arc_cont(D_INIT, "%lXh)\n", *p);
                                openparen = 0;

                                /* register the card */
                                if (com90xx_found(*port, airq, ptr, base) == 0)
                                        found = 1;
                                numprint = -1;

                                /* remove shmem from the list */
                                shmems[index] = shmems[--numshmems];
                                iomem[index] = iomem[numshmems];
                                break;  /* go to the next I/O port */
                        } else {
                                arc_cont(D_INIT_REASONS, "%Xh-",
                                         arcnet_readb(base, COM9026_REG_R_STATUS));
                        }
                }

                if (openparen) {
                        if (BUGLVL(D_INIT))
                                pr_cont("no matching shmem)\n");
                        if (BUGLVL(D_INIT_REASONS)) {
                                pr_cont("S5: ");
                                numprint = 0;
                        }
                }
                if (!found)
                        release_region(*port, ARCNET_TOTAL_SIZE);
                *port-- = ports[--numports];
        }

        if (BUGLVL(D_INIT_REASONS))
                pr_cont("\n");

        /* Now put back TESTvalue on all leftover shmems. */
        for (index = 0; index < numshmems; index++) {
                arcnet_writeb(TESTvalue, iomem[index], COM9026_REG_W_INTMASK);
                iounmap(iomem[index]);
                release_mem_region(shmems[index], MIRROR_SIZE);
        }
        kfree(shmems);
        kfree(iomem);
}

static int __init 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 com90xx_found(int ioaddr, int airq, u_long shmem,
                                void __iomem *p)
{
        struct net_device *dev = NULL;
        struct arcnet_local *lp;
        u_long first_mirror, last_mirror;
        int mirror_size;

        /* allocate struct net_device */
        dev = alloc_arcdev(device);
        if (!dev) {
                arc_cont(D_NORMAL, "com90xx: Can't allocate device!\n");
                iounmap(p);
                release_mem_region(shmem, MIRROR_SIZE);
                return -ENOMEM;
        }
        lp = netdev_priv(dev);
        /* 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;

        iounmap(p);
        release_mem_region(shmem, MIRROR_SIZE);

        if (!request_mem_region(dev->mem_start,
                                dev->mem_end - dev->mem_start + 1,
                                "arcnet (90xx)"))
                goto err_free_dev;

        /* reserve the irq */
        if (request_irq(airq, arcnet_interrupt, 0, "arcnet (90xx)", dev)) {
                arc_printk(D_NORMAL, dev, "Can't get IRQ %d!\n", airq);
                goto err_release_mem;
        }
        dev->irq = airq;

        /* Initialize the rest of the device structure. */
        lp->card_name = "COM90xx";
        lp->hw.command = com90xx_command;
        lp->hw.status = com90xx_status;
        lp->hw.intmask = com90xx_setmask;
        lp->hw.reset = com90xx_reset;
        lp->hw.owner = THIS_MODULE;
        lp->hw.copy_to_card = com90xx_copy_to_card;
        lp->hw.copy_from_card = com90xx_copy_from_card;
        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_free_irq;
        }

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

        dev->base_addr = ioaddr;

        arc_printk(D_NORMAL, dev, "COM90xx station %02Xh found at %03lXh, IRQ %d, ShMem %lXh (%ld*%xh).\n",
                   dev->dev_addr[0],
                   dev->base_addr, dev->irq, dev->mem_start,
                   (dev->mem_end - dev->mem_start + 1) / mirror_size,
                   mirror_size);

        if (register_netdev(dev))
                goto err_unmap;

        cards[numcards++] = dev;
        return 0;

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

static void com90xx_command(struct net_device *dev, int cmd)
{
        short ioaddr = dev->base_addr;

        arcnet_outb(cmd, ioaddr, COM9026_REG_W_COMMAND);
}

static int com90xx_status(struct net_device *dev)
{
        short ioaddr = dev->base_addr;

        return arcnet_inb(ioaddr, COM9026_REG_R_STATUS);
}

static void com90xx_setmask(struct net_device *dev, int mask)
{
        short ioaddr = dev->base_addr;

        arcnet_outb(mask, ioaddr, COM9026_REG_W_INTMASK);
}

/* 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 com90xx_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 (status=%02Xh)\n",
                   arcnet_inb(ioaddr, COM9026_REG_R_STATUS));

        if (really_reset) {
                /* reset the card */
                arcnet_inb(ioaddr, COM9026_REG_R_RESET);
                mdelay(RESETtime);
        }
        /* clear flags & end reset */
        arcnet_outb(CFLAGScmd | RESETclear, ioaddr, COM9026_REG_W_COMMAND);
        arcnet_outb(CFLAGScmd | CONFIGclear, ioaddr, COM9026_REG_W_COMMAND);

#if 0
        /* don't do this until we verify that it doesn't hurt older cards! */
        arcnet_outb(arcnet_inb(ioaddr, COM9026_REG_RW_CONFIG) | ENABLE16flag,
                    ioaddr, COM9026_REG_RW_CONFIG);
#endif

        /* verify that the ARCnet signature byte is present */
        if (arcnet_readb(lp->mem_start, COM9026_REG_R_STATUS) != TESTvalue) {
                if (really_reset)
                        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);

        /* clean out all the memory to make debugging make more sense :) */
        if (BUGLVL(D_DURING))
                memset_io(lp->mem_start, 0x42, 2048);

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

static void com90xx_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 + bufnum * 512 + offset;

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

static void com90xx_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 + bufnum * 512 + offset;

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

MODULE_LICENSE("GPL");

static int __init com90xx_init(void)
{
        if (irq == 2)
                irq = 9;
        com90xx_probe();
        if (!numcards)
                return -EIO;
        return 0;
}

static void __exit com90xx_exit(void)
{
        struct net_device *dev;
        struct arcnet_local *lp;
        int count;

        for (count = 0; count < numcards; count++) {
                dev = cards[count];
                lp = netdev_priv(dev);

                unregister_netdev(dev);
                free_irq(dev->irq, dev);
                iounmap(lp->mem_start);
                release_region(dev->base_addr, ARCNET_TOTAL_SIZE);
                release_mem_region(dev->mem_start,
                                   dev->mem_end - dev->mem_start + 1);
                free_arcdev(dev);
        }
}

module_init(com90xx_init);
module_exit(com90xx_exit);

#ifndef MODULE
static int __init com90xx_setup(char *s)
{
        int ints[8];

        s = get_options(s, 8, ints);
        if (!ints[0] && !*s) {
                pr_notice("Disabled\n");
                return 1;
        }

        switch (ints[0]) {
        default:                /* ERROR */
                pr_err("Too many arguments\n");
                fallthrough;
        case 3:         /* Mem address */
                shmem = ints[3];
                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("com90xx=", com90xx_setup);
#endif