[PATCH] fix semaphore handling in __unregister_chrdev_region

[linux/fpc-iii.git] / drivers / net / oaknet.c

/*
 *
 *    Copyright (c) 1999-2000 Grant Erickson <grant@lcse.umn.edu>
 *
 *    Module name: oaknet.c
 *
 *    Description:
 *      Driver for the National Semiconductor DP83902AV Ethernet controller
 *      on-board the IBM PowerPC "Oak" evaluation board. Adapted from the
 *      various other 8390 drivers written by Donald Becker and Paul Gortmaker.
 *
 *      Additional inspiration from the "tcd8390.c" driver from TiVo, Inc. 
 *      and "enetLib.c" from IBM.
 *
 */

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/init.h>

#include <asm/board.h>
#include <asm/io.h>

#include "8390.h"


/* Preprocessor Defines */

#if !defined(TRUE) || TRUE != 1
#define TRUE    1
#endif

#if !defined(FALSE) || FALSE != 0
#define FALSE   0
#endif

#define OAKNET_START_PG         0x20    /* First page of TX buffer */
#define OAKNET_STOP_PG          0x40    /* Last pagge +1 of RX ring */

#define OAKNET_WAIT             (2 * HZ / 100)  /* 20 ms */

/* Experimenting with some fixes for a broken driver... */

#define OAKNET_DISINT
#define OAKNET_HEADCHECK
#define OAKNET_RWFIX


/* Global Variables */

static const char *name = "National DP83902AV";

static struct net_device *oaknet_devs;


/* Function Prototypes */

static int       oaknet_open(struct net_device *dev);
static int       oaknet_close(struct net_device *dev);

static void      oaknet_reset_8390(struct net_device *dev);
static void      oaknet_get_8390_hdr(struct net_device *dev,
                                     struct e8390_pkt_hdr *hdr, int ring_page);
static void      oaknet_block_input(struct net_device *dev, int count,
                                    struct sk_buff *skb, int ring_offset);
static void      oaknet_block_output(struct net_device *dev, int count,
                                     const unsigned char *buf, int start_page);

static void      oaknet_dma_error(struct net_device *dev, const char *name);


/*
 * int oaknet_init()
 *
 * Description:
 *   This routine performs all the necessary platform-specific initiali-
 *   zation and set-up for the IBM "Oak" evaluation board's National
 *   Semiconductor DP83902AV "ST-NIC" Ethernet controller.
 *
 * Input(s):
 *   N/A
 *
 * Output(s):
 *   N/A
 *
 * Returns:
 *   0 if OK, otherwise system error number on error.
 *
 */
static int __init oaknet_init(void)
{
        register int i;
        int reg0, regd;
        int ret = -ENOMEM;
        struct net_device *dev;
#if 0
        unsigned long ioaddr = OAKNET_IO_BASE; 
#else
        unsigned long ioaddr = ioremap(OAKNET_IO_BASE, OAKNET_IO_SIZE);
#endif
        bd_t *bip = (bd_t *)__res;

        if (!ioaddr)
                return -ENOMEM;

        dev = alloc_ei_netdev();
        if (!dev)
                goto out_unmap;

        ret = -EBUSY;
        if (!request_region(OAKNET_IO_BASE, OAKNET_IO_SIZE, name))
                goto out_dev;

        /* Quick register check to see if the device is really there. */

        ret = -ENODEV;
        if ((reg0 = ei_ibp(ioaddr)) == 0xFF)
                goto out_region;

        /*
         * That worked. Now a more thorough check, using the multicast
         * address registers, that the device is definitely out there
         * and semi-functional.
         */

        ei_obp(E8390_NODMA + E8390_PAGE1 + E8390_STOP, ioaddr + E8390_CMD);
        regd = ei_ibp(ioaddr + 0x0D);
        ei_obp(0xFF, ioaddr + 0x0D);
        ei_obp(E8390_NODMA + E8390_PAGE0, ioaddr + E8390_CMD);
        ei_ibp(ioaddr + EN0_COUNTER0);

        /* It's no good. Fix things back up and leave. */

        ret = -ENODEV;
        if (ei_ibp(ioaddr + EN0_COUNTER0) != 0) {
                ei_obp(reg0, ioaddr);
                ei_obp(regd, ioaddr + 0x0D);
                goto out_region;
        }

        SET_MODULE_OWNER(dev);

        /*
         * This controller is on an embedded board, so the base address
         * and interrupt assignments are pre-assigned and unchageable.
         */

        dev->base_addr = ioaddr;
        dev->irq = OAKNET_INT;

        /*
         * Disable all chip interrupts for now and ACK all pending
         * interrupts.
         */

        ei_obp(0x0, ioaddr + EN0_IMR);
        ei_obp(0xFF, ioaddr + EN0_ISR);

        /* Attempt to get the interrupt line */

        ret = -EAGAIN;
        if (request_irq(dev->irq, ei_interrupt, 0, name, dev)) {
                printk("%s: unable to request interrupt %d.\n",
                       name, dev->irq);
                goto out_region;
        }

        /* Tell the world about what and where we've found. */

        printk("%s: %s at", dev->name, name);
        for (i = 0; i < ETHER_ADDR_LEN; ++i) {
                dev->dev_addr[i] = bip->bi_enetaddr[i];
                printk("%c%.2x", (i ? ':' : ' '), dev->dev_addr[i]);
        }
        printk(", found at %#lx, using IRQ %d.\n", dev->base_addr, dev->irq);

        /* Set up some required driver fields and then we're done. */

        ei_status.name          = name;
        ei_status.word16        = FALSE;
        ei_status.tx_start_page = OAKNET_START_PG;
        ei_status.rx_start_page = OAKNET_START_PG + TX_PAGES;
        ei_status.stop_page     = OAKNET_STOP_PG;

        ei_status.reset_8390    = &oaknet_reset_8390;
        ei_status.block_input   = &oaknet_block_input;
        ei_status.block_output  = &oaknet_block_output;
        ei_status.get_8390_hdr  = &oaknet_get_8390_hdr;

        dev->open = oaknet_open;
        dev->stop = oaknet_close;
#ifdef CONFIG_NET_POLL_CONTROLLER
        dev->poll_controller = ei_poll;
#endif

        NS8390_init(dev, FALSE);
        ret = register_netdev(dev);
        if (ret)
                goto out_irq;
        
        oaknet_devs = dev;
        return 0;

out_irq;
        free_irq(dev->irq, dev);
out_region:
        release_region(OAKNET_IO_BASE, OAKNET_IO_SIZE);
out_dev:
        free_netdev(dev);
out_unmap:
        iounmap(ioaddr);
        return ret;
}

/*
 * static int oaknet_open()
 *
 * Description:
 *   This routine is a modest wrapper around ei_open, the 8390-generic,
 *   driver open routine. This just increments the module usage count
 *   and passes along the status from ei_open.
 *
 * Input(s):
 *  *dev - Pointer to the device structure for this driver.
 *
 * Output(s):
 *  *dev - Pointer to the device structure for this driver, potentially
 *         modified by ei_open.
 *
 * Returns:
 *   0 if OK, otherwise < 0 on error.
 *
 */
static int
oaknet_open(struct net_device *dev)
{
        int status = ei_open(dev);
        return (status);
}

/*
 * static int oaknet_close()
 *
 * Description:
 *   This routine is a modest wrapper around ei_close, the 8390-generic,
 *   driver close routine. This just decrements the module usage count
 *   and passes along the status from ei_close.
 *
 * Input(s):
 *  *dev - Pointer to the device structure for this driver.
 *
 * Output(s):
 *  *dev - Pointer to the device structure for this driver, potentially
 *         modified by ei_close.
 *
 * Returns:
 *   0 if OK, otherwise < 0 on error.
 *
 */
static int
oaknet_close(struct net_device *dev)
{
        int status = ei_close(dev);
        return (status);
}

/*
 * static void oaknet_reset_8390()
 *
 * Description:
 *   This routine resets the DP83902 chip.
 *
 * Input(s):
 *  *dev - Pointer to the device structure for this driver.
 *
 * Output(s):
 *   N/A
 *
 * Returns:
 *   N/A
 *
 */
static void
oaknet_reset_8390(struct net_device *dev)
{
        int base = E8390_BASE;

        /*
         * We have no provision of reseting the controller as is done
         * in other drivers, such as "ne.c". However, the following
         * seems to work well enough in the TiVo driver.
         */

        printk("Resetting %s...\n", dev->name);
        ei_obp(E8390_STOP | E8390_NODMA | E8390_PAGE0, base + E8390_CMD);
        ei_status.txing = 0;
        ei_status.dmaing = 0;
}

/*
 * static void oaknet_get_8390_hdr()
 *
 * Description:
 *   This routine grabs the 8390-specific header. It's similar to the
 *   block input routine, but we don't need to be concerned with ring wrap
 *   as the header will be at the start of a page, so we optimize accordingly.
 *
 * Input(s):
 *  *dev       - Pointer to the device structure for this driver.
 *  *hdr       - Pointer to storage for the 8390-specific packet header.
 *   ring_page - ?
 *
 * Output(s):
 *  *hdr       - Pointer to the 8390-specific packet header for the just-
 *               received frame.
 *
 * Returns:
 *   N/A
 *
 */
static void
oaknet_get_8390_hdr(struct net_device *dev, struct e8390_pkt_hdr *hdr,
                    int ring_page)
{
        int base = dev->base_addr;

        /*
         * This should NOT happen. If it does, it is the LAST thing you'll
         * see.
         */

        if (ei_status.dmaing) {
                oaknet_dma_error(dev, "oaknet_get_8390_hdr");
                return;
        }

        ei_status.dmaing |= 0x01;
        outb_p(E8390_NODMA + E8390_PAGE0 + E8390_START, base + OAKNET_CMD);
        outb_p(sizeof(struct e8390_pkt_hdr), base + EN0_RCNTLO);
        outb_p(0, base + EN0_RCNTHI);
        outb_p(0, base + EN0_RSARLO);           /* On page boundary */
        outb_p(ring_page, base + EN0_RSARHI);
        outb_p(E8390_RREAD + E8390_START, base + OAKNET_CMD);

        if (ei_status.word16)
                insw(base + OAKNET_DATA, hdr,
                     sizeof(struct e8390_pkt_hdr) >> 1);
        else
                insb(base + OAKNET_DATA, hdr,
                     sizeof(struct e8390_pkt_hdr));

        /* Byte-swap the packet byte count */

        hdr->count = le16_to_cpu(hdr->count);

        outb_p(ENISR_RDC, base + EN0_ISR);      /* ACK Remote DMA interrupt */
        ei_status.dmaing &= ~0x01;
}

/*
 * XXX - Document me.
 */
static void
oaknet_block_input(struct net_device *dev, int count, struct sk_buff *skb,
                   int ring_offset)
{
        int base = OAKNET_BASE;
        char *buf = skb->data;

        /*
         * This should NOT happen. If it does, it is the LAST thing you'll
         * see.
         */

        if (ei_status.dmaing) {
                oaknet_dma_error(dev, "oaknet_block_input");
                return;
        }

#ifdef OAKNET_DISINT
        save_flags(flags);
        cli();
#endif

        ei_status.dmaing |= 0x01;
        ei_obp(E8390_NODMA + E8390_PAGE0 + E8390_START, base + E8390_CMD);
        ei_obp(count & 0xff, base + EN0_RCNTLO);
        ei_obp(count >> 8, base + EN0_RCNTHI);
        ei_obp(ring_offset & 0xff, base + EN0_RSARLO);
        ei_obp(ring_offset >> 8, base + EN0_RSARHI);
        ei_obp(E8390_RREAD + E8390_START, base + E8390_CMD);
        if (ei_status.word16) {
                ei_isw(base + E8390_DATA, buf, count >> 1);
                if (count & 0x01) {
                        buf[count - 1] = ei_ib(base + E8390_DATA);
#ifdef OAKNET_HEADCHECK
                        bytes++;
#endif
                }
        } else {
                ei_isb(base + E8390_DATA, buf, count);
        }
#ifdef OAKNET_HEADCHECK
        /*
         * This was for the ALPHA version only, but enough people have
         * been encountering problems so it is still here.  If you see
         * this message you either 1) have a slightly incompatible clone
         * or 2) have noise/speed problems with your bus.
         */

        /* DMA termination address check... */
        {
                int addr, tries = 20;
                do {
                        /* DON'T check for 'ei_ibp(EN0_ISR) & ENISR_RDC' here
                           -- it's broken for Rx on some cards! */
                        int high = ei_ibp(base + EN0_RSARHI);
                        int low = ei_ibp(base + EN0_RSARLO);
                        addr = (high << 8) + low;
                        if (((ring_offset + bytes) & 0xff) == low)
                                break;
                } while (--tries > 0);
                if (tries <= 0)
                        printk("%s: RX transfer address mismatch,"
                               "%#4.4x (expected) vs. %#4.4x (actual).\n",
                               dev->name, ring_offset + bytes, addr);
        }
#endif
        ei_obp(ENISR_RDC, base + EN0_ISR);      /* ACK Remote DMA interrupt */
        ei_status.dmaing &= ~0x01;

#ifdef OAKNET_DISINT
        restore_flags(flags);
#endif
}

/*
 * static void oaknet_block_output()
 *
 * Description:
 *   This routine...
 *
 * Input(s):
 *  *dev        - Pointer to the device structure for this driver.
 *   count      - Number of bytes to be transferred.
 *  *buf        - 
 *   start_page - 
 *
 * Output(s):
 *   N/A
 *
 * Returns:
 *   N/A
 *
 */
static void
oaknet_block_output(struct net_device *dev, int count,
                    const unsigned char *buf, int start_page)
{
        int base = E8390_BASE;
#if 0
        int bug;
#endif
        unsigned long start;
#ifdef OAKNET_DISINT
        unsigned long flags;
#endif
#ifdef OAKNET_HEADCHECK
        int retries = 0;
#endif

        /* Round the count up for word writes. */

        if (ei_status.word16 && (count & 0x1))
                count++;

        /*
         * This should NOT happen. If it does, it is the LAST thing you'll
         * see.
         */

        if (ei_status.dmaing) {
                oaknet_dma_error(dev, "oaknet_block_output");
                return;
        }

#ifdef OAKNET_DISINT
        save_flags(flags);
        cli();
#endif

        ei_status.dmaing |= 0x01;

        /* Make sure we are in page 0. */

        ei_obp(E8390_PAGE0 + E8390_START + E8390_NODMA, base + E8390_CMD);

#ifdef OAKNET_HEADCHECK
retry:
#endif

#if 0
        /*
         * The 83902 documentation states that the processor needs to
         * do a "dummy read" before doing the remote write to work
         * around a chip bug they don't feel like fixing.
         */

        bug = 0;
        while (1) {
                unsigned int rdhi;
                unsigned int rdlo;

                /* Now the normal output. */
                ei_obp(ENISR_RDC, base + EN0_ISR);
                ei_obp(count & 0xff, base + EN0_RCNTLO);
                ei_obp(count >> 8,   base + EN0_RCNTHI);
                ei_obp(0x00, base + EN0_RSARLO);
                ei_obp(start_page, base + EN0_RSARHI);

                if (bug++)
                        break;

                /* Perform the dummy read */
                rdhi = ei_ibp(base + EN0_CRDAHI);
                rdlo = ei_ibp(base + EN0_CRDALO);
                ei_obp(E8390_RREAD + E8390_START, base + E8390_CMD);

                while (1) {
                        unsigned int nrdhi;
                        unsigned int nrdlo;
                        nrdhi = ei_ibp(base + EN0_CRDAHI);
                        nrdlo = ei_ibp(base + EN0_CRDALO);
                        if ((rdhi != nrdhi) || (rdlo != nrdlo))
                                break;
                }
        }
#else
#ifdef OAKNET_RWFIX
        /*
         * Handle the read-before-write bug the same way as the
         * Crynwr packet driver -- the Nat'l Semi. method doesn't work.
         * Actually this doesn't always work either, but if you have
         * problems with your 83902 this is better than nothing!
         */

        ei_obp(0x42, base + EN0_RCNTLO);
        ei_obp(0x00, base + EN0_RCNTHI);
        ei_obp(0x42, base + EN0_RSARLO);
        ei_obp(0x00, base + EN0_RSARHI);
        ei_obp(E8390_RREAD + E8390_START, base + E8390_CMD);
        /* Make certain that the dummy read has occurred. */
        udelay(6);
#endif

        ei_obp(ENISR_RDC, base + EN0_ISR);

        /* Now the normal output. */
        ei_obp(count & 0xff, base + EN0_RCNTLO);
        ei_obp(count >> 8,   base + EN0_RCNTHI);
        ei_obp(0x00, base + EN0_RSARLO);
        ei_obp(start_page, base + EN0_RSARHI);
#endif /* 0/1 */

        ei_obp(E8390_RWRITE + E8390_START, base + E8390_CMD);
        if (ei_status.word16) {
                ei_osw(E8390_BASE + E8390_DATA, buf, count >> 1);
        } else {
                ei_osb(E8390_BASE + E8390_DATA, buf, count);
        }

#ifdef OAKNET_DISINT
        restore_flags(flags);
#endif

        start = jiffies;

#ifdef OAKNET_HEADCHECK
        /*
         * This was for the ALPHA version only, but enough people have
         * been encountering problems so it is still here.
         */
        
        {
                /* DMA termination address check... */
                int addr, tries = 20;
                do {
                        int high = ei_ibp(base + EN0_RSARHI);
                        int low = ei_ibp(base + EN0_RSARLO);
                        addr = (high << 8) + low;
                        if ((start_page << 8) + count == addr)
                                break;
                } while (--tries > 0);

                if (tries <= 0) {
                        printk("%s: Tx packet transfer address mismatch,"
                               "%#4.4x (expected) vs. %#4.4x (actual).\n",
                               dev->name, (start_page << 8) + count, addr);
                        if (retries++ == 0)
                                goto retry;
                }
        }
#endif

        while ((ei_ibp(base + EN0_ISR) & ENISR_RDC) == 0) {
                if (jiffies - start > OAKNET_WAIT) {
                        printk("%s: timeout waiting for Tx RDC.\n", dev->name);
                        oaknet_reset_8390(dev);
                        NS8390_init(dev, TRUE);
                        break;
                }
        }
        
        ei_obp(ENISR_RDC, base + EN0_ISR);      /* Ack intr. */
        ei_status.dmaing &= ~0x01;
}

/*
 * static void oaknet_dma_error()
 *
 * Description:
 *   This routine prints out a last-ditch informative message to the console
 *   indicating that a DMA error occurred. If you see this, it's the last
 *   thing you'll see.
 *
 * Input(s):
 *  *dev  - Pointer to the device structure for this driver.
 *  *name - Informative text (e.g. function name) indicating where the
 *          DMA error occurred.
 *
 * Output(s):
 *   N/A
 *
 * Returns:
 *   N/A
 *
 */
static void
oaknet_dma_error(struct net_device *dev, const char *name)
{
        printk(KERN_EMERG "%s: DMAing conflict in %s."
               "[DMAstat:%d][irqlock:%d][intr:%ld]\n",
               dev->name, name, ei_status.dmaing, ei_status.irqlock,
               dev->interrupt);
}

/*
 * Oak Ethernet module unload interface.
 */
static void __exit oaknet_cleanup_module (void)
{
        /* Convert to loop once driver supports multiple devices. */
        unregister_netdev(oaknet_dev);
        free_irq(oaknet_devs->irq, oaknet_devs);
        release_region(oaknet_devs->base_addr, OAKNET_IO_SIZE);
        iounmap(ioaddr);
        free_netdev(oaknet_devs);
}

module_init(oaknet_init);
module_exit(oaknet_cleanup_module);
MODULE_LICENSE("GPL");