Import 2.3.10pre5

[davej-history.git] / drivers / net / cosa.c

/* $Id: cosa.c,v 1.24 1999/05/28 17:28:34 kas Exp $ */

/*
 *  Copyright (C) 1995-1997  Jan "Yenya" Kasprzak <kas@fi.muni.cz>
 * 
 *      5/25/1999 : Marcelo Tosatti <marcelo@conectiva.com.br>
 *              fixed a deadlock in cosa_sppp_open 
 *
 *  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.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/*
 * The driver for the SRP and COSA synchronous serial cards.
 *
 * HARDWARE INFO
 *
 * Both cards are developed at the Institute of Computer Science,
 * Masaryk University (http://www.ics.muni.cz/). The hardware is
 * developed by Jiri Novotny <novotny@ics.muni.cz>. More information
 * and the photo of both cards is available at
 * http://www.pavoucek.cz/cosa.html. The card documentation, firmwares
 * and other goods can be downloaded from ftp://ftp.ics.muni.cz/pub/cosa/.
 * For Linux-specific utilities, see below in the "Software info" section.
 * If you want to order the card, contact Jiri Novotny.
 *
 * The SRP (serial port?, the Czech word "srp" means "sickle") card
 * is a 2-port intelligent (with its own 8-bit CPU) synchronous serial card
 * with V.24 interfaces up to 80kb/s each.
 *
 * The COSA (communication serial adapter?, the Czech word "kosa" means
 * "scythe") is a next-generation sync/async board with two interfaces
 * - currently any of V.24, X.21, V.35 and V.36 can be selected.
 * It has a 16-bit SAB80166 CPU and can do up to 10 Mb/s per channel.
 * The 8-channels version is in development.
 *
 * Both types have downloadable firmware and communicate via ISA DMA.
 * COSA can be also a bus-mastering device.
 *
 * SOFTWARE INFO
 *
 * The homepage of the Linux driver is at http://www.fi.muni.cz/~kas/cosa/.
 * The CVS tree of Linux driver can be viewed there, as well as the
 * firmware binaries and user-space utilities for downloading the firmware
 * into the card and setting up the card.
 *
 * The Linux driver (unlike the present *BSD drivers :-) can work even
 * for the COSA and SRP in one computer and allows each channel to work
 * in one of the three modes (character device, Cisco HDLC, Sync PPP).
 *
 * AUTHOR
 *
 * The Linux driver was written by Jan "Yenya" Kasprzak <kas@fi.muni.cz>.
 *
 * You can mail me bugfixes and even success reports. I am especially
 * interested in the SMP and/or muliti-channel success/failure reports
 * (I wonder if I did the locking properly :-).
 *
 * THE AUTHOR USED THE FOLLOWING SOURCES WHEN PROGRAMMING THE DRIVER
 *
 * The COSA/SRP NetBSD driver by Zdenek Salvet and Ivos Cernohlavek
 * The skeleton.c by Donald Becker
 * The SDL Riscom/N2 driver by Mike Natale
 * The Comtrol Hostess SV11 driver by Alan Cox
 * The Sync PPP/Cisco HDLC layer (syncppp.c) ported to Linux by Alan Cox
 */
/*
 *     5/25/1999 : Marcelo Tosatti <marcelo@conectiva.com.br>
 *             fixed a deadlock in cosa_sppp_open
 */
\f
/* ---------- Headers, macros, data structures ---------- */

#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/malloc.h>
#include <linux/poll.h>
#include <linux/fs.h>
#include <linux/sched.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/netdevice.h>

#undef COSA_SLOW_IO     /* for testing purposes only */
#undef REALLY_SLOW_IO

#include <asm/io.h>
#include <asm/dma.h>
#include <asm/byteorder.h>
#include <asm/spinlock.h>

#include "syncppp.h"
#include "cosa.h"

/* Maximum length of the identification string. */
#define COSA_MAX_ID_STRING      128

/* Maximum length of the channel name */
#define COSA_MAX_NAME           (sizeof("cosaXXXcXXX")+1)

/* Per-channel data structure */

struct channel_data {
        int usage;      /* Usage count; >0 for chrdev, -1 for netdev */
        int num;        /* Number of the channel */
        struct cosa_data *cosa; /* Pointer to the per-card structure */
        int txsize;     /* Size of transmitted data */
        char *txbuf;    /* Transmit buffer */
        char name[COSA_MAX_NAME];       /* channel name */

        /* The HW layer interface */
        /* routine called from the RX interrupt */
        char *(*setup_rx)(struct channel_data *channel, int size);
        /* routine called when the RX is done (from the EOT interrupt) */
        int (*rx_done)(struct channel_data *channel);
        /* routine called when the TX is done (from the EOT interrupt) */
        int (*tx_done)(struct channel_data *channel, int size);

        /* Character device parts */
        struct semaphore rsem, wsem;
        char *rxdata;
        int rxsize;
        wait_queue_head_t txwaitq; 
        wait_queue_head_t rxwaitq;
        int tx_status, rx_status;

        /* SPPP/HDLC device parts */
        struct ppp_device pppdev;
        struct sk_buff *rx_skb, *tx_skb;
        struct net_device_stats stats;
};

struct cosa_data {
        int num;                        /* Card number */
        char name[COSA_MAX_NAME];       /* Card name - e.g "cosa0" */
        unsigned int datareg, statusreg;        /* I/O ports */
        unsigned short irq, dma;        /* IRQ and DMA number */
        unsigned short startaddr;       /* Firmware start address */
        unsigned short busmaster;       /* Use busmastering? */
        int nchannels;                  /* # of channels on this card */
        int driver_status;              /* For communicating with firware */
        int firmware_status;            /* Downloaded, reseted, etc. */
        int rxbitmap, txbitmap;         /* Bitmap of channels who are willing to send/receive data */
        int rxtx;                       /* RX or TX in progress? */
        int enabled;
        int usage;                              /* usage count */
        int txchan, txsize, rxsize;
        struct channel_data *rxchan;
        char *bouncebuf;
        char *txbuf, *rxbuf;
        struct channel_data *chan;
        spinlock_t lock;        /* For exclusive operations on this structure */
        char id_string[COSA_MAX_ID_STRING];     /* ROM monitor ID string */
        char *type;                             /* card type */
};

/*
 * Define this if you want all the possible ports to be autoprobed.
 * It is here but it probably is not a good idea to use this.
 */
/* #define COSA_ISA_AUTOPROBE   1 */

/*
 * Character device major number. 117 was allocated for us.
 * The value of 0 means to allocate a first free one.
 */
static int cosa_major = 117;

/*
 * Encoding of the minor numbers:
 * The lowest CARD_MINOR_BITS bits means the channel on the single card,
 * the highest bits means the card number.
 */
#define CARD_MINOR_BITS 4       /* How many bits in minor number are reserved
                                 * for the single card */
/*
 * The following depends on CARD_MINOR_BITS. Unfortunately, the "MODULE_STRING"
 * macro doesn't like anything other than the raw number as an argument :-(
 */
#define MAX_CARDS       16
/* #define MAX_CARDS    (1 << (8-CARD_MINOR_BITS)) */

#define DRIVER_RX_READY         0x0001
#define DRIVER_TX_READY         0x0002
#define DRIVER_TXMAP_SHIFT      2
#define DRIVER_TXMAP_MASK       0x0c    /* FIXME: 0xfc for 8-channel version */

/*
 * for cosa->rxtx - indicates whether either transmit or receive is
 * in progress. These values are mean number of the bit.
 */
#define TXBIT 0
#define RXBIT 1
#define IRQBIT 2

#define COSA_MTU 2000   /* FIXME: I don't know this exactly */

#undef DEBUG_DATA 1     /* Dump the data read or written to the channel */
#undef DEBUG_IRQS 1     /* Print the message when the IRQ is received */
#undef DEBUG_IO 1       /* Dump the I/O traffic */

/* Maybe the following should be allocated dynamically */
static struct cosa_data cosa_cards[MAX_CARDS];
static int nr_cards = 0;

#ifdef COSA_ISA_AUTOPROBE
static int io[MAX_CARDS+1]  = { 0x220, 0x228, 0x210, 0x218, 0, };
/* NOTE: DMA is not autoprobed!!! */
static int dma[MAX_CARDS+1] = { 1, 7, 1, 7, 1, 7, 1, 7, 0, };
#else
int io[MAX_CARDS+1]  = { 0, };
int dma[MAX_CARDS+1] = { 0, };
#endif
/* IRQ can be safely autoprobed */
static int irq[MAX_CARDS+1] = { -1, -1, -1, -1, -1, -1, 0, };

#ifdef MODULE
MODULE_PARM(io, "1-" __MODULE_STRING(MAX_CARDS) "i");
MODULE_PARM_DESC(io, "The I/O bases of the COSA or SRP cards");
MODULE_PARM(irq, "1-" __MODULE_STRING(MAX_CARDS) "i");
MODULE_PARM_DESC(irq, "The IRQ lines of the COSA or SRP cards");
MODULE_PARM(dma, "1-" __MODULE_STRING(MAX_CARDS) "i");
MODULE_PARM_DESC(dma, "The DMA channels of the COSA or SRP cards");

MODULE_AUTHOR("Jan \"Yenya\" Kasprzak, <kas@fi.muni.cz>");
MODULE_DESCRIPTION("Modular driver for the COSA or SRP synchronous card");
#endif

/* I use this mainly for testing purposes */
#ifdef COSA_SLOW_IO
#define cosa_outb outb_p
#define cosa_outw outw_p
#define cosa_inb  inb_p
#define cosa_inw  inw_p
#else
#define cosa_outb outb
#define cosa_outw outw
#define cosa_inb  inb
#define cosa_inw  inw
#endif

#define is_8bit(cosa)           (!(cosa->datareg & 0x08))

#define cosa_getstatus(cosa)    (cosa_inb(cosa->statusreg))
#define cosa_putstatus(cosa, stat)      (cosa_outb(stat, cosa->statusreg))
#define cosa_getdata16(cosa)    (cosa_inw(cosa->datareg))
#define cosa_getdata8(cosa)     (cosa_inb(cosa->datareg))
#define cosa_putdata16(cosa, dt)        (cosa_outw(dt, cosa->datareg))
#define cosa_putdata8(cosa, dt) (cosa_outb(dt, cosa->datareg))

/* Initialization stuff */
static int cosa_probe(int ioaddr, int irq, int dma);

/* HW interface */
static void cosa_enable_rx(struct channel_data *chan);
static void cosa_disable_rx(struct channel_data *chan);
static int cosa_start_tx(struct channel_data *channel, char *buf, int size);
static void cosa_kick(struct cosa_data *cosa);
static int cosa_dma_able(struct channel_data *chan, char *buf, int data);

/* SPPP/HDLC stuff */
static void sppp_channel_init(struct channel_data *chan);
static void sppp_channel_delete(struct channel_data *chan);
static int cosa_sppp_open(struct device *d);
static int cosa_sppp_close(struct device *d);
static int cosa_sppp_tx(struct sk_buff *skb, struct device *d);
static char *sppp_setup_rx(struct channel_data *channel, int size);
static int sppp_rx_done(struct channel_data *channel);
static int sppp_tx_done(struct channel_data *channel, int size);
static int cosa_sppp_ioctl(struct device *dev, struct ifreq *ifr, int cmd);
static struct net_device_stats *cosa_net_stats(struct device *dev);

/* Character device */
static void chardev_channel_init(struct channel_data *chan);
static char *chrdev_setup_rx(struct channel_data *channel, int size);
static int chrdev_rx_done(struct channel_data *channel);
static int chrdev_tx_done(struct channel_data *channel, int size);
static long long cosa_lseek(struct file *file,
        long long offset, int origin);
static ssize_t cosa_read(struct file *file,
        char *buf, size_t count, loff_t *ppos);
static ssize_t cosa_write(struct file *file,
        const char *buf, size_t count, loff_t *ppos);
static unsigned int cosa_poll(struct file *file, poll_table *poll);
static int cosa_open(struct inode *inode, struct file *file);
static int cosa_release(struct inode *inode, struct file *file);
static int cosa_chardev_ioctl(struct inode *inode, struct file *file,
        unsigned int cmd, unsigned long arg);
#ifdef COSA_FASYNC_WORKING
static int cosa_fasync(struct inode *inode, struct file *file, int on);
#endif

static struct file_operations cosa_fops = {
        cosa_lseek,
        cosa_read,
        cosa_write,
        NULL,   /* readdir */
        cosa_poll,
        cosa_chardev_ioctl,
        NULL,   /* mmap */
        cosa_open,
        NULL,   /* flush */
        cosa_release,
        NULL,   /* fsync */
#ifdef COSA_FASYNC_WORKING
        cosa_fasync,
#else
        NULL,
#endif
        NULL,   /* check media change */
        NULL,   /* revalidate */
        NULL    /* lock */
};

/* Ioctls */
static int cosa_start(struct cosa_data *cosa, int address);
static int cosa_reset(struct cosa_data *cosa);
static int cosa_download(struct cosa_data *cosa, struct cosa_download *d);
static int cosa_readmem(struct cosa_data *cosa, struct cosa_download *d);

/* COSA/SRP ROM monitor */
static int download(struct cosa_data *cosa, char *data, int addr, int len);
static int startmicrocode(struct cosa_data *cosa, int address);
static int readmem(struct cosa_data *cosa, char *data, int addr, int len);
static int cosa_reset_and_read_id(struct cosa_data *cosa, char *id);

/* Auxilliary functions */
static int get_wait_data(struct cosa_data *cosa);
static int put_wait_data(struct cosa_data *cosa, int data);
static int puthexnumber(struct cosa_data *cosa, int number);
static void put_driver_status(struct cosa_data *cosa);
static void put_driver_status_nolock(struct cosa_data *cosa);

/* Interrupt handling */
static void cosa_interrupt(int irq, void *cosa, struct pt_regs *regs);

/* I/O ops debugging */
#ifdef DEBUG_IO
static void debug_data_in(struct cosa_data *cosa, int data);
static void debug_data_out(struct cosa_data *cosa, int data);
static void debug_data_cmd(struct cosa_data *cosa, int data);
static void debug_status_in(struct cosa_data *cosa, int status);
static void debug_status_out(struct cosa_data *cosa, int status);
#endif

\f
/* ---------- Initialization stuff ---------- */

#ifdef MODULE
int init_module(void)
#else
static int __init cosa_init(void)
#endif
{
        int i;
        printk(KERN_INFO "cosa v1.04 (c) 1997-8 Jan Kasprzak <kas@fi.muni.cz>\n");
#ifdef __SMP__
        printk(KERN_INFO "cosa: SMP found. Please mail any success/failure reports to the author.\n");
#endif
        if (cosa_major > 0) {
                if (register_chrdev(cosa_major, "cosa", &cosa_fops)) {
                        printk(KERN_WARNING "cosa: unable to get major %d\n",
                                cosa_major);
                        return -EIO;
                }
        } else {
                if (!(cosa_major=register_chrdev(0, "cosa", &cosa_fops))) {
                        printk(KERN_WARNING "cosa: unable to register chardev\n");
                        return -EIO;
                }
        }
        for (i=0; i<MAX_CARDS; i++)
                cosa_cards[i].num = -1;
        for (i=0; io[i] != 0 && i < MAX_CARDS; i++)
                cosa_probe(io[i], irq[i], dma[i]);
        if (!nr_cards) {
                printk(KERN_WARNING "cosa: no devices found.\n");
                unregister_chrdev(cosa_major, "cosa");
                return -ENODEV;
        }
        return 0;
}

#ifdef MODULE
void cleanup_module (void)
{
        struct cosa_data *cosa;
        printk(KERN_INFO "Unloading the cosa module\n");

        for (cosa=cosa_cards; nr_cards--; cosa++) {
                int i;
                /* Clean up the per-channel data */
                for (i=0; i<cosa->nchannels; i++) {
                        /* Chardev driver has no alloc'd per-channel data */
                        sppp_channel_delete(cosa->chan+i);
                }
                /* Clean up the per-card data */
                kfree(cosa->chan);
                kfree(cosa->bouncebuf);
                free_irq(cosa->irq, cosa);
                free_dma(cosa->dma);
                release_region(cosa->datareg,is_8bit(cosa)?2:4);
        }
        unregister_chrdev(cosa_major, "cosa");
}
#endif

/*
 * This function should register all the net devices needed for the
 * single channel.
 */
static __inline__ void channel_init(struct channel_data *chan)
{
        sprintf(chan->name, "cosa%dc%d", chan->cosa->num, chan->num);

        /* Initialize the chardev data structures */
        chardev_channel_init(chan);

        /* Register the sppp interface */
        sppp_channel_init(chan);
}
        
static int cosa_probe(int base, int irq, int dma)
{
        struct cosa_data *cosa = cosa_cards+nr_cards;
        int i;

        memset(cosa, 0, sizeof(struct cosa_data));

        /* Checking validity of parameters: */
        /* IRQ should be 2-7 or 10-15; negative IRQ means autoprobe */
        if ((irq >= 0  && irq < 2) || irq > 15 || (irq < 10 && irq > 7)) {
                printk (KERN_INFO "cosa_probe: invalid IRQ %d\n", irq);
                return -1;
        }
        /* I/O address should be between 0x100 and 0x3ff and should be
         * multiple of 8. */
        if (base < 0x100 || base > 0x3ff || base & 0x7) {
                printk (KERN_INFO "cosa_probe: invalid I/O address 0x%x\n",
                        base);
                return -1;
        }
        /* DMA should be 0,1 or 3-7 */
        if (dma < 0 || dma == 4 || dma > 7) {
                printk (KERN_INFO "cosa_probe: invalid DMA %d\n", dma);
                return -1;
        }
        /* and finally, on 16-bit COSA DMA should be 4-7 and 
         * I/O base should not be multiple of 0x10 */
        if (((base & 0x8) && dma < 4) || (!(base & 0x8) && dma > 3)) {
                printk (KERN_INFO "cosa_probe: 8/16 bit base and DMA mismatch"
                        " (base=0x%x, dma=%d)\n", base, dma);
                return -1;
        }

        cosa->dma = dma;
        cosa->datareg = base;
        cosa->statusreg = is_8bit(cosa)?base+1:base+2;
        spin_lock_init(&cosa->lock);

        if (check_region(base, is_8bit(cosa)?2:4))
                return -1;
        
        if (cosa_reset_and_read_id(cosa, cosa->id_string) < 0) {
                printk(KERN_DEBUG "cosa: probe at 0x%x failed.\n", base);
                return -1;
        }

        /* Test the validity of identification string */
        if (!strncmp(cosa->id_string, "SRP", 3))
                cosa->type = "srp";
        else if (!strncmp(cosa->id_string, "COSA", 4))
                cosa->type = is_8bit(cosa)? "cosa8": "cosa16";
        else {
/* Print a warning only if we are not autoprobing */
#ifndef COSA_ISA_AUTOPROBE
                printk(KERN_INFO "cosa: valid signature not found at 0x%x.\n",
                        base);
#endif
                return -1;
        }

        /* Now do IRQ autoprobe */
        if (irq < 0) {
                unsigned long irqs;
/*              printk(KERN_INFO "IRQ autoprobe\n"); */
                sti();
                irqs = probe_irq_on();
                /* 
                 * Enable interrupt on tx buffer empty (it sure is) 
                 * really sure ?
                 * FIXME: When this code is not used as module, we should
                 * probably call udelay() instead of the interruptible sleep.
                 */
                current->state = TASK_INTERRUPTIBLE;
                cosa_putstatus(cosa, SR_TX_INT_ENA);
                schedule_timeout(30);
                current->state = TASK_RUNNING;
                irq = probe_irq_off(irqs);
                /* Disable all IRQs from the card */
                cosa_putstatus(cosa, 0);
                /* Empty the received data register */
                cosa_getdata8(cosa);

                if (irq < 0) {
                        printk (KERN_INFO "cosa IRQ autoprobe: multiple interrupts obtained (%d, board at 0x%x)\n",
                                irq, cosa->datareg);
                        return -1;
                }
                if (irq == 0) {
                        printk (KERN_INFO "cosa IRQ autoprobe: no interrupt obtained (board at 0x%x)\n",
                                cosa->datareg);
                /*      return -1; */
                }
        }

        cosa->irq = irq;
        cosa->num = nr_cards;
        cosa->usage = 0;
        cosa->nchannels = 2;    /* FIXME: how to determine this? */

        request_region(base, is_8bit(cosa)?2:4, cosa->type);
        if (request_irq(cosa->irq, cosa_interrupt, 0, cosa->type, cosa))
                goto bad1;
        if (request_dma(cosa->dma, cosa->type)) {
                free_irq(cosa->irq, cosa);
bad1:           release_region(cosa->datareg,is_8bit(cosa)?2:4);
                printk(KERN_NOTICE "cosa%d: allocating resources failed\n",
                        cosa->num);
                return -1;
        }
        
        cosa->bouncebuf = kmalloc(COSA_MTU, GFP_KERNEL|GFP_DMA);
        sprintf(cosa->name, "cosa%d", cosa->num);

        /* Initialize the per-channel data */
        cosa->chan = kmalloc(sizeof(struct channel_data)*cosa->nchannels,
                GFP_KERNEL);
        memset(cosa->chan, 0, sizeof(struct channel_data)*cosa->nchannels);
        for (i=0; i<cosa->nchannels; i++) {
                cosa->chan[i].cosa = cosa;
                cosa->chan[i].num = i;
                channel_init(cosa->chan+i);
        }

        printk (KERN_INFO "cosa%d: %s (%s at 0x%x irq %d dma %d), %d channels\n",
                cosa->num, cosa->id_string, cosa->type,
                cosa->datareg, cosa->irq, cosa->dma, cosa->nchannels);

        return nr_cards++;
}

\f
/*---------- SPPP/HDLC netdevice ---------- */

static void sppp_channel_init(struct channel_data *chan)
{
        struct device *d;
        sppp_attach(&chan->pppdev);
        d=&chan->pppdev.dev;
        d->name = chan->name;
        d->base_addr = chan->cosa->datareg;
        d->irq = chan->cosa->irq;
        d->dma = chan->cosa->dma;
        d->priv = chan;
        d->init = NULL;
        d->open = cosa_sppp_open;
        d->stop = cosa_sppp_close;
        d->hard_start_xmit = cosa_sppp_tx;
        d->do_ioctl = cosa_sppp_ioctl;
        d->get_stats = cosa_net_stats;
        dev_init_buffers(d);
        if (register_netdev(d) == -1) {
                printk(KERN_WARNING "%s: register_netdev failed.\n", d->name);
                sppp_detach(&chan->pppdev.dev);
                return;
        }
}

static void sppp_channel_delete(struct channel_data *chan)
{
        sppp_detach(&chan->pppdev.dev);
        unregister_netdev(&chan->pppdev.dev);
}


static int cosa_sppp_open(struct device *d)
{
        struct channel_data *chan = d->priv;
        int err, flags;

        spin_lock_irqsave(&chan->cosa->lock, flags);
        if (chan->usage != 0) {
                printk(KERN_WARNING "%s: sppp_open called with usage count %d\n",
                        chan->name, chan->usage);
                spin_unlock_irqrestore(&chan->cosa->lock, flags);
                return -EBUSY;
        }
        chan->setup_rx = sppp_setup_rx;
        chan->tx_done = sppp_tx_done;
        chan->rx_done = sppp_rx_done;
        chan->usage=-1;
        chan->cosa->usage++;
        MOD_INC_USE_COUNT;
        spin_unlock_irqrestore(&chan->cosa->lock, flags);

        err = sppp_open(d);
        if (err) {
                spin_lock_irqsave(&chan->cosa->lock, flags);
                chan->usage=0;
                chan->cosa->usage--;
                MOD_DEC_USE_COUNT;
                
                spin_unlock_irqrestore(&chan->cosa->lock, flags);
                return err;
        }

        d->tbusy = 0;
        cosa_enable_rx(chan);
        return 0;
}

static int cosa_sppp_tx(struct sk_buff *skb, struct device *dev)
{
        struct channel_data *chan = dev->priv;

        if (dev->tbusy) { 
                if (time_before(jiffies, dev->trans_start+2*HZ))
                        return 1;       /* Two seconds timeout */
                if (test_bit(RXBIT, &chan->cosa->rxtx)) {
                        chan->stats.rx_errors++;
                        chan->stats.rx_missed_errors++;
                } else {
                        chan->stats.tx_errors++;
                        chan->stats.tx_aborted_errors++;
                }
                cosa_kick(chan->cosa);
                if (chan->tx_skb) {
                        dev_kfree_skb(chan->tx_skb);
                        chan->tx_skb = 0;
                }
                dev->tbusy = 0;
        }
        if (test_and_set_bit(0, (void*)&dev->tbusy) != 0) {
                printk(KERN_WARNING "%s: Transmitter access conflict.\n", dev->name);
                return 1;
        }
        
        chan->tx_skb = skb;
        dev->trans_start = jiffies;
        cosa_start_tx(chan, skb->data, skb->len);
        return 0;
}

static int cosa_sppp_close(struct device *d)
{
        struct channel_data *chan = d->priv;
        int flags;

        sppp_close(d);
        d->tbusy = 1;
        cosa_disable_rx(chan);
        spin_lock_irqsave(&chan->cosa->lock, flags);
        if (chan->rx_skb) {
                kfree_skb(chan->rx_skb);
                chan->rx_skb = 0;
        }
        if (chan->tx_skb) {
                kfree_skb(chan->tx_skb);
                chan->tx_skb = 0;
        }
        chan->usage=0;
        chan->cosa->usage--;
        MOD_DEC_USE_COUNT;
        spin_unlock_irqrestore(&chan->cosa->lock, flags);
        return 0;
}

static char *sppp_setup_rx(struct channel_data *chan, int size)
{
        /*
         * We can safely fall back to non-dma-able memory, because we have
         * the cosa->bouncebuf pre-allocated.
         */
        if (chan->rx_skb)
                kfree_skb(chan->rx_skb);
        chan->rx_skb = dev_alloc_skb(size);
        if (chan->rx_skb == NULL) {
                printk(KERN_NOTICE "%s: Memory squeeze, dropping packet\n",
                        chan->name);
                chan->stats.rx_dropped++;
                return NULL;
        }
        chan->pppdev.dev.trans_start = jiffies;
        return skb_put(chan->rx_skb, size);
}

static int sppp_rx_done(struct channel_data *chan)
{
        if (!chan->rx_skb) {
                printk(KERN_WARNING "%s: rx_done with empty skb!\n",
                        chan->name);
                chan->stats.rx_errors++;
                chan->stats.rx_frame_errors++;
                return 0;
        }
        chan->rx_skb->protocol = htons(ETH_P_WAN_PPP);
        chan->rx_skb->dev = &chan->pppdev.dev;
        chan->rx_skb->mac.raw = chan->rx_skb->data;
        chan->stats.rx_packets++;
        chan->stats.rx_bytes += chan->cosa->rxsize;
        netif_rx(chan->rx_skb);
        chan->rx_skb = 0;
        chan->pppdev.dev.trans_start = jiffies;
        return 0;
}

/* ARGSUSED */
static int sppp_tx_done(struct channel_data *chan, int size)
{
        if (!chan->tx_skb) {
                printk(KERN_WARNING "%s: tx_done with empty skb!\n",
                        chan->name);
                chan->stats.tx_errors++;
                chan->stats.tx_aborted_errors++;
                return 1;
        }
        dev_kfree_skb(chan->tx_skb);
        chan->tx_skb = 0;
        chan->stats.tx_packets++;
        chan->stats.tx_bytes += size;
        chan->pppdev.dev.tbusy = 0;
        mark_bh(NET_BH);
        return 1;
}

static struct net_device_stats *cosa_net_stats(struct device *dev)
{
        struct channel_data *chan = dev->priv;
        return &chan->stats;
}

\f
/*---------- Character device ---------- */

static void chardev_channel_init(struct channel_data *chan)
{
        init_MUTEX(&chan->rsem);
        init_MUTEX(&chan->wsem);
}

static long long cosa_lseek(struct file * file,
        long long offset, int origin)
{
        return -ESPIPE;
}

static ssize_t cosa_read(struct file *file,
        char *buf, size_t count, loff_t *ppos)
{
        DECLARE_WAITQUEUE(wait, current);
        int flags;
        struct channel_data *chan = (struct channel_data *)file->private_data;
        struct cosa_data *cosa = chan->cosa;
        char *kbuf;

        if (down_interruptible(&chan->rsem))
                return -ERESTARTSYS;
        
        if ((chan->rxdata = kmalloc(COSA_MTU, GFP_DMA|GFP_KERNEL)) == NULL) {
                printk(KERN_INFO "%s: cosa_read() - OOM\n", cosa->name);
                up(&chan->rsem);
                return -ENOMEM;
        }

        chan->rx_status = 0;
        cosa_enable_rx(chan);
        spin_lock_irqsave(&cosa->lock, flags);
        add_wait_queue(&chan->rxwaitq, &wait);
        while(!chan->rx_status) {
                current->state = TASK_INTERRUPTIBLE;
                spin_unlock_irqrestore(&cosa->lock, flags);
                schedule();
                spin_lock_irqsave(&cosa->lock, flags);
                if (signal_pending(current) && chan->rx_status == 0) {
                        chan->rx_status = 1;
                        remove_wait_queue(&chan->rxwaitq, &wait);
                        current->state = TASK_RUNNING;
                        spin_unlock_irqrestore(&cosa->lock, flags);
                        up(&chan->rsem);
                        return -ERESTARTSYS;
                }
        }
        remove_wait_queue(&chan->rxwaitq, &wait);
        current->state = TASK_RUNNING;
        kbuf = chan->rxdata;
        count = chan->rxsize;
        spin_unlock_irqrestore(&cosa->lock, flags);
        up(&chan->rsem);

        if (copy_to_user(buf, kbuf, count)) {
                kfree(buf);
                return -EFAULT;
        }
        kfree(kbuf);
        return count;
}

static char *chrdev_setup_rx(struct channel_data *chan, int size)
{
        /* Expect size <= COSA_MTU */
        chan->rxsize = size;
        return chan->rxdata;
}

static int chrdev_rx_done(struct channel_data *chan)
{
        if (chan->rx_status) { /* Reader has died */
                kfree(chan->rxdata);
                up(&chan->wsem);
        }
        chan->rx_status = 1;
        wake_up_interruptible(&chan->rxwaitq);
        return 1;
}


static ssize_t cosa_write(struct file *file,
        const char *buf, size_t count, loff_t *ppos)
{
        struct channel_data *chan = (struct channel_data *)file->private_data;
        DECLARE_WAITQUEUE(wait, current);
        struct cosa_data *cosa = chan->cosa;
        unsigned int flags;
        char *kbuf;

        if (down_interruptible(&chan->wsem))
                return -ERESTARTSYS;

        if (count > COSA_MTU)
                count = COSA_MTU;
        
        /* Allocate the buffer */
        if ((kbuf = kmalloc(count, GFP_KERNEL|GFP_DMA)) == NULL) {
                printk(KERN_NOTICE "%s: cosa_write() OOM - dropping packet\n",
                        cosa->name);
                up(&chan->wsem);
                return -ENOMEM;
        }
        if (copy_from_user(kbuf, buf, count)) {
                up(&chan->wsem);
                kfree(kbuf);
                return -EFAULT;
        }
        chan->tx_status=0;
        cosa_start_tx(chan, kbuf, count);

        spin_lock_irqsave(&cosa->lock, flags);
        add_wait_queue(&chan->txwaitq, &wait);
        while(!chan->tx_status) {
                current->state = TASK_INTERRUPTIBLE;
                spin_unlock_irqrestore(&cosa->lock, flags);
                schedule();
                spin_lock_irqsave(&cosa->lock, flags);
                if (signal_pending(current) && chan->tx_status == 0) {
                        chan->tx_status = 1;
                        remove_wait_queue(&chan->txwaitq, &wait);
                        current->state = TASK_RUNNING;
                        chan->tx_status = 1;
                        spin_unlock_irqrestore(&cosa->lock, flags);
                        return -ERESTARTSYS;
                }
        }
        remove_wait_queue(&chan->txwaitq, &wait);
        current->state = TASK_RUNNING;
        up(&chan->wsem);
        spin_unlock_irqrestore(&cosa->lock, flags);
        kfree(kbuf);
        return count;
}

static int chrdev_tx_done(struct channel_data *chan, int size)
{
        if (chan->tx_status) { /* Writer was interrupted */
                kfree(chan->txbuf);
                up(&chan->wsem);
        }
        chan->tx_status = 1;
        wake_up_interruptible(&chan->txwaitq);
        return 1;
}

static unsigned int cosa_poll(struct file *file, poll_table *poll)
{
        printk(KERN_INFO "cosa_poll is here\n");
        return 0;
}

static int cosa_open(struct inode *inode, struct file *file)
{
        struct cosa_data *cosa;
        struct channel_data *chan;
        unsigned long flags;
        int n;

        if ((n=MINOR(file->f_dentry->d_inode->i_rdev)>>CARD_MINOR_BITS)
                >= nr_cards)
                return -ENODEV;
        cosa = cosa_cards+n;

        if ((n=MINOR(file->f_dentry->d_inode->i_rdev)
                & ((1<<CARD_MINOR_BITS)-1)) >= cosa->nchannels)
                return -ENODEV;
        chan = cosa->chan + n;
        
        file->private_data = chan;

        spin_lock_irqsave(&cosa->lock, flags);

        if (chan->usage < 0) { /* in netdev mode */
                spin_unlock_irqrestore(&cosa->lock, flags);
                return -EBUSY;
        }
        cosa->usage++;
        chan->usage++;

        chan->tx_done = chrdev_tx_done;
        chan->setup_rx = chrdev_setup_rx;
        chan->rx_done = chrdev_rx_done;
#ifdef MODULE
        MOD_INC_USE_COUNT;
#endif
        spin_unlock_irqrestore(&cosa->lock, flags);
        return 0;
}

static int cosa_release(struct inode *inode, struct file *file)
{
        struct channel_data *channel = (struct channel_data *)file->private_data;
        struct cosa_data *cosa = channel->cosa;
        unsigned long flags;

        spin_lock_irqsave(&cosa->lock, flags);
        cosa->usage--;
        channel->usage--;
#ifdef MODULE
        MOD_DEC_USE_COUNT;
#endif
        spin_unlock_irqrestore(&cosa->lock, flags);
        return 0;
}

#ifdef COSA_FASYNC_WORKING
static struct fasync_struct *fasync[256] = { NULL, };

/* To be done ... */
static int cosa_fasync(struct inode *inode, struct file *file, int on)
{
        int port = MINOR(inode->i_rdev);
        int rv = fasync_helper(inode, file, on, &fasync[port]);
        return rv < 0 ? rv : 0;
}
#endif

\f
/* ---------- Ioctls ---------- */

/*
 * Ioctl subroutines can safely be made inline, because they are called
 * only from cosa_ioctl().
 */
static inline int cosa_reset(struct cosa_data *cosa)
{
        char idstring[COSA_MAX_ID_STRING];
        if (cosa->usage > 1)
                printk(KERN_INFO "cosa%d: WARNING: reset requested with cosa->usage > 1 (%d). Odd things may happen.\n",
                        cosa->num, cosa->usage);
        if (cosa_reset_and_read_id(cosa, idstring) < 0) {
                printk(KERN_NOTICE "cosa%d: reset failed\n", cosa->num);
                return -EIO;
        }
        printk(KERN_INFO "cosa%d: resetting device: %s\n", cosa->num,
                idstring);
        return 0;
}

/* High-level function to download data into COSA memory. Calls download() */
static inline int cosa_download(struct cosa_data *cosa, struct cosa_download *d)
{
        int i;
        int addr, len;
        char *code;

        if (cosa->usage > 1)
                printk(KERN_INFO "cosa%d: WARNING: download of microcode requested with cosa->usage > 1 (%d). Odd things may happen.\n",
                        cosa->num, cosa->usage);
#if 0
        if (cosa->status != CARD_STATUS_RESETED && cosa->status != CARD_STATUS_DOWNLOADED) {
                printk(KERN_NOTICE "cosa%d: reset the card first (status %d).\n",
                        cosa->num, cosa->status);
                return -EPERM;
        }
#endif
        get_user_ret(addr, &(d->addr), -EFAULT);
        get_user_ret(len, &(d->len), -EFAULT);
        get_user_ret(code, &(d->code), -EFAULT);

        if (d->addr < 0 || d->addr > COSA_MAX_FIRMWARE_SIZE)
                return -EINVAL;
        if (d->len < 0 || d->len > COSA_MAX_FIRMWARE_SIZE)
                return -EINVAL;

        if ((i=download(cosa, d->code, len, addr)) < 0) {
                printk(KERN_NOTICE "cosa%d: microcode download failed: %d\n",
                        cosa->num, i);
                return -EIO;
        }
        printk(KERN_INFO "cosa%d: downloading microcode - 0x%04x bytes at 0x%04x\n",
                cosa->num, len, addr);
        return 0;
}

/* High-level function to read COSA memory. Calls readmem() */
static inline int cosa_readmem(struct cosa_data *cosa, struct cosa_download *d)
{
        int i;
        int addr, len;
        char *code;

        if (cosa->usage > 1)
                printk(KERN_INFO "cosa%d: WARNING: readmem requested with "
                        "cosa->usage > 1 (%d). Odd things may happen.\n",
                        cosa->num, cosa->usage);
#if 0
        if (cosa->status != CARD_STATUS_RESETED &&
                cosa->status != CARD_STATUS_DOWNLOADED) {
                printk(KERN_NOTICE "cosa%d: reset the card first (status %d).\n",
                        cosa->num, cosa->status);
                return -EPERM;
        }
#endif
        get_user_ret(addr, &(d->addr), -EFAULT);
        get_user_ret(len, &(d->len), -EFAULT);
        get_user_ret(code, &(d->code), -EFAULT);

        if ((i=readmem(cosa, d->code, len, addr)) < 0) {
                printk(KERN_NOTICE "cosa%d: reading memory failed: %d\n",
                        cosa->num, i);
                return -EIO;
        }
        printk(KERN_INFO "cosa%d: reading card memory - 0x%04x bytes at 0x%04x\n",
                cosa->num, len, addr);
        return 0;
}

/* High-level function to start microcode. Calls startmicrocode(). */
static inline int cosa_start(struct cosa_data *cosa, int address)
{
        int i;

        if (cosa->usage > 1)
                printk(KERN_INFO "cosa%d: WARNING: start microcode requested with cosa->usage > 1 (%d). Odd things may happen.\n",
                        cosa->num, cosa->usage);
#if 0
        if (cosa->status != CARD_STATUS_DOWNLOADED) {
                printk(KERN_NOTICE "cosa%d: download the microcode first (status %d).\n",
                        cosa->num, cosa->status);
                return -EPERM;
        }
#endif
        if ((i=startmicrocode(cosa, address)) < 0) {
                printk(KERN_NOTICE "cosa%d: start microcode at 0x%04x failed: %d\n",
                        cosa->num, address, i);
                return -EIO;
        }
        printk(KERN_INFO "cosa%d: starting microcode at 0x%04x\n",
                cosa->num, address);
        cosa->startaddr = address;
        return 0;
}
                
/* Buffer of size at least COSA_MAX_ID_STRING is expected */
static inline int cosa_getidstr(struct cosa_data *cosa, char *string)
{
        int l = strlen(cosa->id_string)+1;
        copy_to_user_ret(string, cosa->id_string, l, -EFAULT);
        return l;
}

/* Buffer of size at least COSA_MAX_ID_STRING is expected */
static inline int cosa_gettype(struct cosa_data *cosa, char *string)
{
        int l = strlen(cosa->type)+1;
        copy_to_user_ret(string, cosa->type, l, -EFAULT);
        return l;
}

static int cosa_ioctl_common(struct cosa_data *cosa,
        struct channel_data *channel, unsigned int cmd, unsigned long arg)
{
        switch(cmd) {
        case COSAIORSET:        /* Reset the device */
                if (!suser())
                        return -EACCES;
                return cosa_reset(cosa);
        case COSAIOSTRT:        /* Start the firmware */
                if (!suser())
                        return -EACCES;
                return cosa_start(cosa, arg);
        case COSAIODOWNLD:      /* Download the firmware */
                if (!suser())
                        return -EACCES;
                return cosa_download(cosa, (struct cosa_download *)arg);
        case COSAIORMEM:
                if (!suser())
                        return -EACCES;
                return cosa_readmem(cosa, (struct cosa_download *)arg);
        case COSAIORTYPE:
                return cosa_gettype(cosa, (char *)arg);
        case COSAIORIDSTR:
                return cosa_getidstr(cosa, (char *)arg);
/*
 * These two are _very_ugly_hack_(tm). Don't even look at this.
 * Implementing this saved me few reboots after some process segfaulted
 * inside this module.
 */
#ifdef MODULE
#if 0
        case COSAIOMINC:
                MOD_INC_USE_COUNT;
                return 0;
        case COSAIOMDEC:
                MOD_DEC_USE_COUNT;
                return 0;
#endif
#endif
        case COSAIONRCARDS:
                return nr_cards;
        case COSAIONRCHANS:
                return cosa->nchannels;
        case COSAIOBMSET:
                if (!suser())
                        return -EACCES;
                if (is_8bit(cosa))
                        return -EINVAL;
                if (arg != COSA_BM_OFF && arg != COSA_BM_ON)
                        return -EINVAL;
                cosa->busmaster = arg;
                return 0;
        case COSAIOBMGET:
                return cosa->busmaster;
        }
        return -ENOIOCTLCMD;
}

static int cosa_sppp_ioctl(struct device *dev, struct ifreq *ifr,
        int cmd)
{
        int rv;
        struct channel_data *chan = (struct channel_data *)dev->priv;
        rv = cosa_ioctl_common(chan->cosa, chan, cmd, (int)ifr->ifr_data);
        if (rv == -ENOIOCTLCMD) {
                return sppp_do_ioctl(dev, ifr, cmd);
        }
        return rv;
}

static int cosa_chardev_ioctl(struct inode *inode, struct file *file,
        unsigned int cmd, unsigned long arg)
{
        struct channel_data *channel = (struct channel_data *)file->private_data;
        struct cosa_data *cosa = channel->cosa;
        return cosa_ioctl_common(cosa, channel, cmd, arg);
}

\f
/*---------- HW layer interface ---------- */

/*
 * The higher layer can bind itself to the HW layer by setting the callbacks
 * in the channel_data structure and by using these routines.
 */
static void cosa_enable_rx(struct channel_data *chan)
{
        struct cosa_data *cosa = chan->cosa;

        if (!test_and_set_bit(chan->num, &cosa->rxbitmap))
                put_driver_status(cosa);
}

static void cosa_disable_rx(struct channel_data *chan)
{
        struct cosa_data *cosa = chan->cosa;

        if (test_and_clear_bit(chan->num, &cosa->rxbitmap))
                put_driver_status(cosa);
}

/*
 * FIXME: This routine probably should check for cosa_start_tx() called when
 * the previous transmit is still unfinished. In this case the non-zero
 * return value should indicate to the caller that the queuing(sp?) up
 * the transmit has failed.
 */
static int cosa_start_tx(struct channel_data *chan, char *buf, int len)
{
        struct cosa_data *cosa = chan->cosa;
        int flags;
#ifdef DEBUG_DATA
        int i;

        printk(KERN_INFO "cosa%dc%d: starting tx(0x%x)", chan->cosa->num,
                chan->num, len);
        for (i=0; i<len; i++)
                printk(" %02x", buf[i]&0xff);
        printk("\n");
#endif
        spin_lock_irqsave(&cosa->lock, flags);
        chan->txbuf = buf;
        chan->txsize = len;
        if (len > COSA_MTU)
                chan->txsize = COSA_MTU;
        spin_unlock_irqrestore(&cosa->lock, flags);

        /* Tell the firmware we are ready */
        set_bit(chan->num, &cosa->txbitmap);
        put_driver_status(cosa);

        return 0;
}

static void put_driver_status(struct cosa_data *cosa)
{
        unsigned flags=0;
        int status;

        spin_lock_irqsave(&cosa->lock, flags);

        status = (cosa->rxbitmap ? DRIVER_RX_READY : 0)
                | (cosa->txbitmap ? DRIVER_TX_READY : 0)
                | (cosa->txbitmap? ~(cosa->txbitmap<<DRIVER_TXMAP_SHIFT)
                        &DRIVER_TXMAP_MASK : 0);
        if (!cosa->rxtx) {
                if (cosa->rxbitmap|cosa->txbitmap) {
                        if (!cosa->enabled) {
                                cosa_putstatus(cosa, SR_RX_INT_ENA);
#ifdef DEBUG_IO
                                debug_status_out(cosa, SR_RX_INT_ENA);
#endif
                                cosa->enabled = 1;
                        }
                } else if (cosa->enabled) {
                        cosa->enabled = 0;
                        cosa_putstatus(cosa, 0);
#ifdef DEBUG_IO
                        debug_status_out(cosa, 0);
#endif
                }
                cosa_putdata8(cosa, 0);
                cosa_putdata8(cosa, status);
#ifdef DEBUG_IO
                debug_data_cmd(cosa, 0);
                debug_data_cmd(cosa, status);
#endif
        }
        spin_unlock_irqrestore(&cosa->lock, flags);
}

static void put_driver_status_nolock(struct cosa_data *cosa)
{
        int status;

        status = (cosa->rxbitmap ? DRIVER_RX_READY : 0)
                | (cosa->txbitmap ? DRIVER_TX_READY : 0)
                | (cosa->txbitmap? ~(cosa->txbitmap<<DRIVER_TXMAP_SHIFT)
                        &DRIVER_TXMAP_MASK : 0);

        if (cosa->rxbitmap|cosa->txbitmap) {
                cosa_putstatus(cosa, SR_RX_INT_ENA);
#ifdef DEBUG_IO
                debug_status_out(cosa, SR_RX_INT_ENA);
#endif
                cosa->enabled = 1;
        } else {
                cosa_putstatus(cosa, 0);
#ifdef DEBUG_IO
                debug_status_out(cosa, 0);
#endif
                cosa->enabled = 0;
        }
        cosa_putdata8(cosa, status);
#ifdef DEBUG_IO
        debug_data_cmd(cosa, status);
#endif
}

/*
 * The "kickme" function: When the DMA times out, this is called to
 * clean up the driver status.
 * FIXME: Preliminary support, the interface is probably wrong.
 */
static void cosa_kick(struct cosa_data *cosa)
{
        unsigned flags, flags1;
        char *s = "Unknown";

        if (test_bit(RXBIT, &cosa->rxtx))
                s = "RX";
        if (test_bit(TXBIT, &cosa->rxtx))
                s = "TX";

        printk(KERN_INFO "%s: %s DMA timeout - restarting.\n", cosa->name, s); 
        spin_lock_irqsave(&cosa->lock, flags);
        cosa->rxtx = 0;

        flags1 = claim_dma_lock();
        disable_dma(cosa->dma);
        clear_dma_ff(cosa->dma);
        release_dma_lock(flags1);

        /* FIXME: Anything else? */
        udelay(100);
        cosa_putstatus(cosa, 0);
        udelay(100);
        (void) cosa_getdata8(cosa);
        udelay(100);
        cosa_putdata8(cosa, 0);
        udelay(100);
        put_driver_status_nolock(cosa);
        spin_unlock_irqrestore(&cosa->lock, flags);
}

/*
 * Check if the whole buffer is DMA-able. It means it is below the 16M of
 * physical memory and doesn't span the 64k boundary. For now it seems
 * SKB's never do this, but we'll check this anyway.
 */
static int cosa_dma_able(struct channel_data *chan, char *buf, int len)
{
        static int count = 0;
        unsigned long b = (unsigned long)buf;
        if (b+len >= MAX_DMA_ADDRESS)
                return 0;
        if ((b^ (b+len)) & 0x10000) {
                if (count++ < 5)
                        printk(KERN_INFO "%s: packet spanning a 64k boundary\n",
                                chan->name);
                return 0;
        }
        return 1;
}

\f
/* ---------- The SRP/COSA ROM monitor functions ---------- */

/*
 * Downloading SRP microcode: say "w" to SRP monitor, it answers by "w=",
 * drivers need to say 4-digit hex number meaning start address of the microcode
 * separated by a single space. Monitor replies by saying " =". Now driver
 * has to write 4-digit hex number meaning the last byte address ended
 * by a single space. Monitor has to reply with a space. Now the download
 * begins. After the download monitor replies with "\r\n." (CR LF dot).
 */
static int download(struct cosa_data *cosa, char *microcode, int length, int address)
{
        int i;

        if (put_wait_data(cosa, 'w') == -1) return -1;
        if ((i=get_wait_data(cosa)) != 'w') { printk("dnld: 0x%04x\n",i); return -2;}
        if (get_wait_data(cosa) != '=') return -3;

        if (puthexnumber(cosa, address) < 0) return -4;
        if (put_wait_data(cosa, ' ') == -1) return -10;
        if (get_wait_data(cosa) != ' ') return -11;
        if (get_wait_data(cosa) != '=') return -12;

        if (puthexnumber(cosa, address+length-1) < 0) return -13;
        if (put_wait_data(cosa, ' ') == -1) return -18;
        if (get_wait_data(cosa) != ' ') return -19;

        while (length--) {
                char c;
#ifndef SRP_DOWNLOAD_AT_BOOT
                get_user_ret(c,microcode, -23);
#else
                c = *microcode;
#endif
                if (put_wait_data(cosa, c) == -1)
                        return -20;
                microcode++;
        }

        if (get_wait_data(cosa) != '\r') return -21;
        if (get_wait_data(cosa) != '\n') return -22;
        if (get_wait_data(cosa) != '.') return -23;
#if 0
        printk(KERN_DEBUG "cosa%d: download completed.\n", cosa->num);
#endif
        return 0;
}


/*
 * Starting microcode is done via the "g" command of the SRP monitor.
 * The chat should be the following: "g" "g=" "<addr><CR>"
 * "<CR><CR><LF><CR><LF>".
 */
static int startmicrocode(struct cosa_data *cosa, int address)
{
        if (put_wait_data(cosa, 'g') == -1) return -1;
        if (get_wait_data(cosa) != 'g') return -2;
        if (get_wait_data(cosa) != '=') return -3;

        if (puthexnumber(cosa, address) < 0) return -4;
        if (put_wait_data(cosa, '\r') == -1) return -5;
        
        if (get_wait_data(cosa) != '\r') return -6;
        if (get_wait_data(cosa) != '\r') return -7;
        if (get_wait_data(cosa) != '\n') return -8;
        if (get_wait_data(cosa) != '\r') return -9;
        if (get_wait_data(cosa) != '\n') return -10;
#if 0
        printk(KERN_DEBUG "cosa%d: microcode started\n", cosa->num);
#endif
        return 0;
}

/*
 * Reading memory is done via the "r" command of the SRP monitor.
 * The chat is the following "r" "r=" "<addr> " " =" "<last_byte> " " "
 * Then driver can read the data and the conversation is finished
 * by SRP monitor sending "<CR><LF>." (dot at the end).
 *
 * This routine is not needed during the normal operation and serves
 * for debugging purposes only.
 */
static int readmem(struct cosa_data *cosa, char *microcode, int length, int address)
{
        if (put_wait_data(cosa, 'r') == -1) return -1;
        if ((get_wait_data(cosa)) != 'r') return -2;
        if ((get_wait_data(cosa)) != '=') return -3;

        if (puthexnumber(cosa, address) < 0) return -4;
        if (put_wait_data(cosa, ' ') == -1) return -5;
        if (get_wait_data(cosa) != ' ') return -6;
        if (get_wait_data(cosa) != '=') return -7;

        if (puthexnumber(cosa, address+length-1) < 0) return -8;
        if (put_wait_data(cosa, ' ') == -1) return -9;
        if (get_wait_data(cosa) != ' ') return -10;

        while (length--) {
                char c;
                int i;
                if ((i=get_wait_data(cosa)) == -1) {
                        printk (KERN_INFO "cosa: 0x%04x bytes remaining\n",
                                length);
                        return -11;
                }
                c=i;
#if 1
                put_user_ret(c,microcode, -23);
#else
                *microcode = c;
#endif
                microcode++;
        }

        if (get_wait_data(cosa) != '\r') return -21;
        if (get_wait_data(cosa) != '\n') return -22;
        if (get_wait_data(cosa) != '.') return -23;
#if 0
        printk(KERN_DEBUG "cosa%d: readmem completed.\n", cosa->num);
#endif
        return 0;
}

/*
 * This function resets the device and reads the initial prompt
 * of the device's ROM monitor.
 */
static int cosa_reset_and_read_id(struct cosa_data *cosa, char *idstring)
{
        int i=0, id=0, prev=0, curr=0;

        /* Reset the card ... */
        cosa_putstatus(cosa, 0);
        cosa_getdata8(cosa);
        cosa_putstatus(cosa, SR_RST);
#ifdef MODULE
        current->state = TASK_INTERRUPTIBLE;
        schedule_timeout(HZ/2);
        current->state = TASK_RUNNING;
#else
        udelay(5*100000);
#endif
        /* Disable all IRQs from the card */
        cosa_putstatus(cosa, 0);

        /*
         * Try to read the ID string. The card then prints out the
         * identification string ended by the "\n\x2e".
         *
         * The following loop is indexed through i (instead of id)
         * to avoid looping forever when for any reason
         * the port returns '\r', '\n' or '\x2e' permanently.
         */
        for (i=0; i<COSA_MAX_ID_STRING-1; i++, prev=curr) {
                if ((curr = get_wait_data(cosa)) == -1) {
                        return -1;
                }
                curr &= 0xff;
                if (curr != '\r' && curr != '\n' && curr != 0x2e)
                        idstring[id++] = curr;
                if (curr == 0x2e && prev == '\n')
                        break;
        }
        /* Perhaps we should fail when i==COSA_MAX_ID_STRING-1 ? */
        idstring[id] = '\0';
        return id;
}

\f
/* ---------- Auxiliary routines for COSA/SRP monitor ---------- */

/*
 * This routine gets the data byte from the card waiting for the SR_RX_RDY
 * bit to be set in a loop. It should be used in the exceptional cases
 * only (for example when resetting the card or downloading the firmware.
 */
static int get_wait_data(struct cosa_data *cosa)
{
        int retries = 1000;

        while (--retries) {
                /* read data and return them */
                if (cosa_getstatus(cosa) & SR_RX_RDY) {
                        short r;
                        r = cosa_getdata8(cosa);
#if 0
                        printk(KERN_INFO "cosa: get_wait_data returning after %d retries\n", 999-retries);
#endif
                        return r;
                }
                /* sleep if not ready to read */
                current->state = TASK_INTERRUPTIBLE;
                schedule_timeout(1);
                current->state = TASK_RUNNING;
        }
        printk(KERN_INFO "cosa: timeout in get_wait_data (status 0x%x)\n",
                cosa_getstatus(cosa));
        return -1;
}

/*
 * This routine puts the data byte to the card waiting for the SR_TX_RDY
 * bit to be set in a loop. It should be used in the exceptional cases
 * only (for example when resetting the card or downloading the firmware).
 */
static int put_wait_data(struct cosa_data *cosa, int data)
{
        int retries = 1000;
        while (--retries) {
                /* read data and return them */
                if (cosa_getstatus(cosa) & SR_TX_RDY) {
                        cosa_putdata8(cosa, data);
#if 0
                        printk(KERN_INFO "Putdata: %d retries\n", 999-retries);
#endif
                        return 0;
                }
#if 0
                /* sleep if not ready to read */
                current->state = TASK_INTERRUPTIBLE;
                schedule_timeout(1);
                current->state = TASK_RUNNING;
#endif
        }
        printk(KERN_INFO "cosa%d: timeout in put_wait_data (status 0x%x)\n",
                cosa->num, cosa_getstatus(cosa));
        return -1;
}
        
/* 
 * The following routine puts the hexadecimal number into the SRP monitor
 * and verifies the proper echo of the sent bytes. Returns 0 on success,
 * negative number on failure (-1,-3,-5,-7) means that put_wait_data() failed,
 * (-2,-4,-6,-8) means that reading echo failed.
 */
static int puthexnumber(struct cosa_data *cosa, int number)
{
        char temp[5];
        int i;

        /* Well, I should probably replace this by something faster. */
        sprintf(temp, "%04X", number);
        for (i=0; i<4; i++) {
                if (put_wait_data(cosa, temp[i]) == -1) {
                        printk(KERN_NOTICE "cosa%d: puthexnumber failed to write byte %d\n",
                                cosa->num, i);
                        return -1-2*i;
                }
                if (get_wait_data(cosa) != temp[i]) {
                        printk(KERN_NOTICE "cosa%d: puthexhumber failed to read echo of byte %d\n",
                                cosa->num, i);
                        return -2-2*i;
                }
        }
        return 0;
}

\f
/* ---------- Interrupt routines ---------- */

/*
 * There are three types of interrupt:
 * At the beginning of transmit - this handled is in tx_interrupt(),
 * at the beginning of receive - it is in rx_interrupt() and
 * at the end of transmit/receive - it is the eot_interrupt() function.
 * These functions are multiplexed by cosa_interrupt() according to the
 * COSA status byte. I have moved the rx/tx/eot interrupt handling into
 * separate functions to make it more readable. These functions are inline,
 * so there should be no overhead of function call.
 * 
 * In the COSA bus-master mode, we need to tell the card the address of a
 * buffer. Unfortunately, COSA may be too slow for us, so we must busy-wait.
 * It's time to use the bottom half :-(
 */

/*
 * Transmit interrupt routine - called when COSA is willing to obtain
 * data from the OS. The most tricky part of the routine is selection
 * of channel we (OS) want to send packet for. For SRP we should probably
 * use the round-robin approach. The newer COSA firmwares have a simple
 * flow-control - in the status word has bits 2 and 3 set to 1 means that the
 * channel 0 or 1 doesn't want to receive data.
 */
static inline void tx_interrupt(struct cosa_data *cosa, int status)
{
        unsigned long flags, flags1;
#ifdef DEBUG_IRQS
        printk(KERN_INFO "cosa%d: SR_DOWN_REQUEST status=0x%04x\n",
                cosa->num, status);
#endif
        spin_lock_irqsave(&cosa->lock, flags);
        set_bit(TXBIT, &cosa->rxtx);
        if (!test_bit(IRQBIT, &cosa->rxtx)) {
                /* flow control */
                int i=0;
                do {
                        if (i++ > cosa->nchannels) {
                                printk(KERN_WARNING
                                        "%s: No channel wants data in TX IRQ\n",
                                        cosa->name);
                                put_driver_status_nolock(cosa);
                                clear_bit(TXBIT, &cosa->rxtx);
                                spin_unlock_irqrestore(&cosa->lock, flags);
                                return;
                        }
                        cosa->txchan++;
                        if (cosa->txchan >= cosa->nchannels)
                                cosa->txchan = 0;
                } while ((!(cosa->txbitmap & (1<<cosa->txchan)))
                        || status & (1<<(cosa->txchan+DRIVER_TXMAP_SHIFT)));

                cosa->txsize = cosa->chan[cosa->txchan].txsize;
                if (cosa_dma_able(cosa->chan+cosa->txchan,
                        cosa->chan[cosa->txchan].txbuf, cosa->txsize)) {
                        cosa->txbuf = cosa->chan[cosa->txchan].txbuf;
                } else {
                        memcpy(cosa->bouncebuf, cosa->chan[cosa->txchan].txbuf,
                                cosa->txsize);
                        cosa->txbuf = cosa->bouncebuf;
                }
        }

        if (is_8bit(cosa)) {
                if (!test_bit(IRQBIT, &cosa->rxtx)) {
                        cosa_putstatus(cosa, SR_TX_INT_ENA);
                        cosa_putdata8(cosa, ((cosa->txchan << 5) & 0xe0)|
                                ((cosa->txsize >> 8) & 0x1f));
#ifdef DEBUG_IO
                        debug_status_out(cosa, SR_TX_INT_ENA);
                        debug_data_out(cosa, ((cosa->txchan << 5) & 0xe0)|
                                ((cosa->txsize >> 8) & 0x1f));
                        debug_data_in(cosa, cosa_getdata8(cosa));
#else
                        cosa_getdata8(cosa);
#endif
                        set_bit(IRQBIT, &cosa->rxtx);
                        spin_unlock_irqrestore(&cosa->lock, flags);
                        return;
                } else {
                        clear_bit(IRQBIT, &cosa->rxtx);
                        cosa_putstatus(cosa, 0);
                        cosa_putdata8(cosa, cosa->txsize&0xff);
#ifdef DEBUG_IO
                        debug_status_out(cosa, 0);
                        debug_data_out(cosa, cosa->txsize&0xff);
#endif
                }
        } else {
                cosa_putstatus(cosa, SR_TX_INT_ENA);
                cosa_putdata16(cosa, ((cosa->txchan<<13) & 0xe000)
                        | (cosa->txsize & 0x1fff));
#ifdef DEBUG_IO
                debug_status_out(cosa, SR_TX_INT_ENA);
                debug_data_out(cosa, ((cosa->txchan<<13) & 0xe000)
                        | (cosa->txsize & 0x1fff));
                debug_data_in(cosa, cosa_getdata8(cosa));
                debug_status_out(cosa, 0);
#else
                cosa_getdata8(cosa);
#endif
                cosa_putstatus(cosa, 0);
        }

        if (cosa->busmaster) {
                unsigned long addr = virt_to_bus(cosa->txbuf);
                int count=0;
                printk(KERN_INFO "busmaster IRQ\n");
                while (!(cosa_getstatus(cosa)&SR_TX_RDY)) {
                        count++;
                        udelay(10);
                        if (count > 1000) break;
                }
                printk(KERN_INFO "status %x\n", cosa_getstatus(cosa));
                printk(KERN_INFO "ready after %d loops\n", count);
                cosa_putdata16(cosa, (addr >> 16)&0xffff);

                count = 0;
                while (!(cosa_getstatus(cosa)&SR_TX_RDY)) {
                        count++;
                        if (count > 1000) break;
                        udelay(10);
                }
                printk(KERN_INFO "ready after %d loops\n", count);
                cosa_putdata16(cosa, addr &0xffff);
                flags1 = claim_dma_lock();
                set_dma_mode(cosa->dma, DMA_MODE_CASCADE);
                enable_dma(cosa->dma);
                release_dma_lock(flags1);
        } else {
                /* start the DMA */
                flags1 = claim_dma_lock();
                disable_dma(cosa->dma);
                clear_dma_ff(cosa->dma);
                set_dma_mode(cosa->dma, DMA_MODE_WRITE);
                set_dma_addr(cosa->dma, virt_to_bus(cosa->txbuf));
                set_dma_count(cosa->dma, cosa->txsize);
                enable_dma(cosa->dma);
                release_dma_lock(flags1);
        }
        cosa_putstatus(cosa, SR_TX_DMA_ENA|SR_USR_INT_ENA);
#ifdef DEBUG_IO
        debug_status_out(cosa, SR_TX_DMA_ENA|SR_USR_INT_ENA);
#endif
        spin_unlock_irqrestore(&cosa->lock, flags);
}

static inline void rx_interrupt(struct cosa_data *cosa, int status)
{
        unsigned long flags;
#ifdef DEBUG_IRQS
        printk(KERN_INFO "cosa%d: SR_UP_REQUEST\n", cosa->num);
#endif

        spin_lock_irqsave(&cosa->lock, flags);
        set_bit(RXBIT, &cosa->rxtx);

        if (is_8bit(cosa)) {
                if (!test_bit(IRQBIT, &cosa->rxtx)) {
                        set_bit(IRQBIT, &cosa->rxtx);
                        cosa->rxsize = cosa_getdata8(cosa) <<8;
#ifdef DEBUG_IO
                        debug_data_in(cosa, cosa->rxsize >> 8);
#endif
                        spin_unlock_irqrestore(&cosa->lock, flags);
                        return;
                } else {
                        clear_bit(IRQBIT, &cosa->rxtx);
                        cosa->rxsize |= cosa_getdata8(cosa) & 0xff;
#ifdef DEBUG_IO
                        debug_data_in(cosa, cosa->rxsize & 0xff);
#endif
#if 0
                        printk(KERN_INFO "cosa%d: receive rxsize = (0x%04x).\n",
                                cosa->num, cosa->rxsize);
#endif
                }
        } else {
                cosa->rxsize = cosa_getdata16(cosa);
#ifdef DEBUG_IO
                debug_data_in(cosa, cosa->rxsize);
#endif
#if 0
                printk(KERN_INFO "cosa%d: receive rxsize = (0x%04x).\n",
                        cosa->num, cosa->rxsize);
#endif
        }
        if (((cosa->rxsize & 0xe000) >> 13) >= cosa->nchannels) {
                printk(KERN_WARNING "%s: rx for unknown channel (0x%04x)\n",
                        cosa->name, cosa->rxsize);
                spin_unlock_irqrestore(&cosa->lock, flags);
                goto reject;
        }
        cosa->rxchan = cosa->chan + ((cosa->rxsize & 0xe000) >> 13);
        cosa->rxsize &= 0x1fff;
        spin_unlock_irqrestore(&cosa->lock, flags);

        cosa->rxbuf = NULL;
        if (cosa->rxchan->setup_rx)
                cosa->rxbuf = cosa->rxchan->setup_rx(cosa->rxchan, cosa->rxsize);

        if (!cosa->rxbuf) {
reject:         /* Reject the packet */
                printk(KERN_INFO "cosa%d: rejecting packet on channel %d\n",
                        cosa->num, cosa->rxchan->num);
                cosa->rxbuf = cosa->bouncebuf;
        }

        /* start the DMA */
        flags = claim_dma_lock();
        disable_dma(cosa->dma);
        clear_dma_ff(cosa->dma);
        set_dma_mode(cosa->dma, DMA_MODE_READ);
        if (cosa_dma_able(cosa->rxchan, cosa->rxbuf, cosa->rxsize & 0x1fff)) {
                set_dma_addr(cosa->dma, virt_to_bus(cosa->rxbuf));
        } else {
                set_dma_addr(cosa->dma, virt_to_bus(cosa->bouncebuf));
        }
        set_dma_count(cosa->dma, (cosa->rxsize&0x1fff));
        enable_dma(cosa->dma);
        release_dma_lock(flags);
        spin_lock_irqsave(&cosa->lock, flags);
        cosa_putstatus(cosa, SR_RX_DMA_ENA|SR_USR_INT_ENA);
        if (!is_8bit(cosa) && (status & SR_TX_RDY))
                cosa_putdata8(cosa, DRIVER_RX_READY);
#ifdef DEBUG_IO
        debug_status_out(cosa, SR_RX_DMA_ENA|SR_USR_INT_ENA);
        if (!is_8bit(cosa) && (status & SR_TX_RDY))
                debug_data_cmd(cosa, DRIVER_RX_READY);
#endif
        spin_unlock_irqrestore(&cosa->lock, flags);
}

static void inline eot_interrupt(struct cosa_data *cosa, int status)
{
        unsigned long flags, flags1;
        spin_lock_irqsave(&cosa->lock, flags);
        flags1 = claim_dma_lock();
        disable_dma(cosa->dma);
        clear_dma_ff(cosa->dma);
        release_dma_lock(flags1);
        if (test_bit(TXBIT, &cosa->rxtx)) {
                struct channel_data *chan = cosa->chan+cosa->txchan;
                if (chan->tx_done)
                        if (chan->tx_done(chan, cosa->txsize))
                                clear_bit(chan->num, &cosa->txbitmap);
        } else if (test_bit(RXBIT, &cosa->rxtx)) {
#ifdef DEBUG_DATA
        {
                int i;
                printk(KERN_INFO "cosa%dc%d: done rx(0x%x)", cosa->num, 
                        cosa->rxchan->num, cosa->rxsize);
                for (i=0; i<cosa->rxsize; i++)
                        printk (" %02x", cosa->rxbuf[i]&0xff);
                printk("\n");
        }
#endif
                /* Packet for unknown channel? */
                if (cosa->rxbuf == cosa->bouncebuf)
                        goto out;
                if (!cosa_dma_able(cosa->rxchan, cosa->rxbuf, cosa->rxsize))
                        memcpy(cosa->rxbuf, cosa->bouncebuf, cosa->rxsize);
                if (cosa->rxchan->rx_done)
                        if (cosa->rxchan->rx_done(cosa->rxchan))
                                clear_bit(cosa->rxchan->num, &cosa->rxbitmap);
        } else {
                printk(KERN_NOTICE "cosa%d: unexpected EOT interrupt\n",
                        cosa->num);
        }
        /*
         * Clear the RXBIT, TXBIT and IRQBIT (the latest should be
         * cleared anyway). We should do it as soon as possible
         * so that we can tell the COSA we are done and to give it a time
         * for recovery.
         */
out:
        cosa->rxtx = 0;
        put_driver_status_nolock(cosa);
        spin_unlock_irqrestore(&cosa->lock, flags);
}

static void cosa_interrupt(int irq, void *cosa_, struct pt_regs *regs)
{
        unsigned status;
        int count = 0;
        struct cosa_data *cosa = cosa_;
again:
        status = cosa_getstatus(cosa);
#ifdef DEBUG_IRQS
        printk(KERN_INFO "cosa%d: got IRQ, status 0x%02x\n", cosa->num,
                status & 0xff);
#endif
#ifdef DEBUG_IO
        debug_status_in(cosa, status);
#endif
        switch (status & SR_CMD_FROM_SRP_MASK) {
        case SR_DOWN_REQUEST:
                tx_interrupt(cosa, status);
                break;
        case SR_UP_REQUEST:
                rx_interrupt(cosa, status);
                break;
        case SR_END_OF_TRANSFER:
                eot_interrupt(cosa, status);
                break;
        default:
                /* We may be too fast for SRP. Try to wait a bit more. */
                if (count++ < 100) {
                        udelay(100);
                        goto again;
                }
                printk(KERN_INFO "cosa%d: unknown status 0x%02x in IRQ after %d retries\n",
                        cosa->num, status & 0xff, count);
        }
#ifdef DEBUG_IRQS
        if (count)
                printk(KERN_INFO "%s: %d-times got unknown status in IRQ\n",
                        cosa->name, count);
        else
                printk(KERN_INFO "%s: returning from IRQ\n", cosa->name);
#endif
}

\f
/* ---------- I/O debugging routines ---------- */
/*
 * These routines can be used to monitor COSA/SRP I/O and to printk()
 * the data being transfered on the data and status I/O port in a
 * readable way.
 */

#ifdef DEBUG_IO
static void debug_status_in(struct cosa_data *cosa, int status)
{
        char *s;
        switch(status & SR_CMD_FROM_SRP_MASK) {
        case SR_UP_REQUEST:
                s = "RX_REQ";
                break;
        case SR_DOWN_REQUEST:
                s = "TX_REQ";
                break;
        case SR_END_OF_TRANSFER:
                s = "ET_REQ";
                break;
        default:
                s = "NO_REQ";
                break;
        }
        printk(KERN_INFO "%s: IO: status -> 0x%02x (%s%s%s%s)\n",
                cosa->name,
                status,
                status & SR_USR_RQ ? "USR_RQ|":"",
                status & SR_TX_RDY ? "TX_RDY|":"",
                status & SR_RX_RDY ? "RX_RDY|":"",
                s);
}

static void debug_status_out(struct cosa_data *cosa, int status)
{
        printk(KERN_INFO "%s: IO: status <- 0x%02x (%s%s%s%s%s%s)\n",
                cosa->name,
                status,
                status & SR_RX_DMA_ENA  ? "RXDMA|":"!rxdma|",
                status & SR_TX_DMA_ENA  ? "TXDMA|":"!txdma|",
                status & SR_RST         ? "RESET|":"",
                status & SR_USR_INT_ENA ? "USRINT|":"!usrint|",
                status & SR_TX_INT_ENA  ? "TXINT|":"!txint|",
                status & SR_RX_INT_ENA  ? "RXINT":"!rxint");
}

static void debug_data_in(struct cosa_data *cosa, int data)
{
        printk(KERN_INFO "%s: IO: data -> 0x%04x\n", cosa->name, data);
}

static void debug_data_out(struct cosa_data *cosa, int data)
{
        printk(KERN_INFO "%s: IO: data <- 0x%04x\n", cosa->name, data);
}

static void debug_data_cmd(struct cosa_data *cosa, int data)
{
        printk(KERN_INFO "%s: IO: data <- 0x%04x (%s|%s)\n",
                cosa->name, data,
                data & SR_RDY_RCV ? "RX_RDY" : "!rx_rdy",
                data & SR_RDY_SND ? "TX_RDY" : "!tx_rdy");
}
#endif

/* EOF -- this file has not been truncated */