Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus

[wrt350n-kernel.git] / drivers / net / macsonic.c

/*
 * macsonic.c
 *
 * (C) 2005 Finn Thain
 *
 * Converted to DMA API, converted to unified driver model, made it work as
 * a module again, and from the mac68k project, introduced more 32-bit cards
 * and dhd's support for 16-bit cards.
 *
 * (C) 1998 Alan Cox
 *
 * Debugging Andreas Ehliar, Michael Schmitz
 *
 * Based on code
 * (C) 1996 by Thomas Bogendoerfer (tsbogend@bigbug.franken.de)
 *
 * This driver is based on work from Andreas Busse, but most of
 * the code is rewritten.
 *
 * (C) 1995 by Andreas Busse (andy@waldorf-gmbh.de)
 *
 * A driver for the Mac onboard Sonic ethernet chip.
 *
 * 98/12/21 MSch: judged from tests on Q800, it's basically working,
 *                but eating up both receive and transmit resources
 *                and duplicating packets. Needs more testing.
 *
 * 99/01/03 MSch: upgraded to version 0.92 of the core driver, fixed.
 *
 * 00/10/31 sammy@oh.verio.com: Updated driver for 2.4 kernels, fixed problems
 *          on centris.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/delay.h>
#include <linux/nubus.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>
#include <linux/platform_device.h>
#include <linux/dma-mapping.h>
#include <linux/bitrev.h>

#include <asm/bootinfo.h>
#include <asm/system.h>
#include <asm/pgtable.h>
#include <asm/io.h>
#include <asm/hwtest.h>
#include <asm/dma.h>
#include <asm/macintosh.h>
#include <asm/macints.h>
#include <asm/mac_via.h>

static char mac_sonic_string[] = "macsonic";
static struct platform_device *mac_sonic_device;

#include "sonic.h"

/* These should basically be bus-size and endian independent (since
   the SONIC is at least smart enough that it uses the same endianness
   as the host, unlike certain less enlightened Macintosh NICs) */
#define SONIC_READ(reg) (nubus_readw(dev->base_addr + (reg * 4) \
              + lp->reg_offset))
#define SONIC_WRITE(reg,val) (nubus_writew(val, dev->base_addr + (reg * 4) \
              + lp->reg_offset))

/* use 0 for production, 1 for verification, >1 for debug */
#ifdef SONIC_DEBUG
static unsigned int sonic_debug = SONIC_DEBUG;
#else
static unsigned int sonic_debug = 1;
#endif

static int sonic_version_printed;

extern int mac_onboard_sonic_probe(struct net_device* dev);
extern int mac_nubus_sonic_probe(struct net_device* dev);

/* For onboard SONIC */
#define ONBOARD_SONIC_REGISTERS 0x50F0A000
#define ONBOARD_SONIC_PROM_BASE 0x50f08000

enum macsonic_type {
        MACSONIC_DUODOCK,
        MACSONIC_APPLE,
        MACSONIC_APPLE16,
        MACSONIC_DAYNA,
        MACSONIC_DAYNALINK
};

/* For the built-in SONIC in the Duo Dock */
#define DUODOCK_SONIC_REGISTERS 0xe10000
#define DUODOCK_SONIC_PROM_BASE 0xe12000

/* For Apple-style NuBus SONIC */
#define APPLE_SONIC_REGISTERS   0
#define APPLE_SONIC_PROM_BASE   0x40000

/* Daynalink LC SONIC */
#define DAYNALINK_PROM_BASE 0x400000

/* For Dayna-style NuBus SONIC (haven't seen one yet) */
#define DAYNA_SONIC_REGISTERS   0x180000
/* This is what OpenBSD says.  However, this is definitely in NuBus
   ROM space so we should be able to get it by walking the NuBus
   resource directories */
#define DAYNA_SONIC_MAC_ADDR    0xffe004

#define SONIC_READ_PROM(addr) nubus_readb(prom_addr+addr)

/*
 * For reversing the PROM address
 */

static inline void bit_reverse_addr(unsigned char addr[6])
{
        int i;

        for(i = 0; i < 6; i++)
                addr[i] = bitrev8(addr[i]);
}

static irqreturn_t macsonic_interrupt(int irq, void *dev_id)
{
        irqreturn_t result;
        unsigned long flags;

        local_irq_save(flags);
        result = sonic_interrupt(irq, dev_id);
        local_irq_restore(flags);
        return result;
}

static int macsonic_open(struct net_device* dev)
{
        if (request_irq(dev->irq, &sonic_interrupt, IRQ_FLG_FAST, "sonic", dev)) {
                printk(KERN_ERR "%s: unable to get IRQ %d.\n", dev->name, dev->irq);
                return -EAGAIN;
        }
        /* Under the A/UX interrupt scheme, the onboard SONIC interrupt comes
         * in at priority level 3. However, we sometimes get the level 2 inter-
         * rupt as well, which must prevent re-entrance of the sonic handler.
         */
        if (dev->irq == IRQ_AUTO_3)
                if (request_irq(IRQ_NUBUS_9, &macsonic_interrupt, IRQ_FLG_FAST, "sonic", dev)) {
                        printk(KERN_ERR "%s: unable to get IRQ %d.\n", dev->name, IRQ_NUBUS_9);
                        free_irq(dev->irq, dev);
                        return -EAGAIN;
                }
        return sonic_open(dev);
}

static int macsonic_close(struct net_device* dev)
{
        int err;
        err = sonic_close(dev);
        free_irq(dev->irq, dev);
        if (dev->irq == IRQ_AUTO_3)
                free_irq(IRQ_NUBUS_9, dev);
        return err;
}

int __init macsonic_init(struct net_device* dev)
{
        struct sonic_local* lp = netdev_priv(dev);

        /* Allocate the entire chunk of memory for the descriptors.
           Note that this cannot cross a 64K boundary. */
        if ((lp->descriptors = dma_alloc_coherent(lp->device,
                    SIZEOF_SONIC_DESC * SONIC_BUS_SCALE(lp->dma_bitmode),
                    &lp->descriptors_laddr, GFP_KERNEL)) == NULL) {
                printk(KERN_ERR "%s: couldn't alloc DMA memory for descriptors.\n", lp->device->bus_id);
                return -ENOMEM;
        }

        /* Now set up the pointers to point to the appropriate places */
        lp->cda = lp->descriptors;
        lp->tda = lp->cda + (SIZEOF_SONIC_CDA
                             * SONIC_BUS_SCALE(lp->dma_bitmode));
        lp->rda = lp->tda + (SIZEOF_SONIC_TD * SONIC_NUM_TDS
                             * SONIC_BUS_SCALE(lp->dma_bitmode));
        lp->rra = lp->rda + (SIZEOF_SONIC_RD * SONIC_NUM_RDS
                             * SONIC_BUS_SCALE(lp->dma_bitmode));

        lp->cda_laddr = lp->descriptors_laddr;
        lp->tda_laddr = lp->cda_laddr + (SIZEOF_SONIC_CDA
                             * SONIC_BUS_SCALE(lp->dma_bitmode));
        lp->rda_laddr = lp->tda_laddr + (SIZEOF_SONIC_TD * SONIC_NUM_TDS
                             * SONIC_BUS_SCALE(lp->dma_bitmode));
        lp->rra_laddr = lp->rda_laddr + (SIZEOF_SONIC_RD * SONIC_NUM_RDS
                             * SONIC_BUS_SCALE(lp->dma_bitmode));

        dev->open = macsonic_open;
        dev->stop = macsonic_close;
        dev->hard_start_xmit = sonic_send_packet;
        dev->get_stats = sonic_get_stats;
        dev->set_multicast_list = &sonic_multicast_list;
        dev->tx_timeout = sonic_tx_timeout;
        dev->watchdog_timeo = TX_TIMEOUT;

        /*
         * clear tally counter
         */
        SONIC_WRITE(SONIC_CRCT, 0xffff);
        SONIC_WRITE(SONIC_FAET, 0xffff);
        SONIC_WRITE(SONIC_MPT, 0xffff);

        return 0;
}

int __init mac_onboard_sonic_ethernet_addr(struct net_device* dev)
{
        struct sonic_local *lp = netdev_priv(dev);
        const int prom_addr = ONBOARD_SONIC_PROM_BASE;
        int i;
        DECLARE_MAC_BUF(mac);

        /* On NuBus boards we can sometimes look in the ROM resources.
           No such luck for comm-slot/onboard. */
        for(i = 0; i < 6; i++)
                dev->dev_addr[i] = SONIC_READ_PROM(i);

        /* Most of the time, the address is bit-reversed.  The NetBSD
           source has a rather long and detailed historical account of
           why this is so. */
        if (memcmp(dev->dev_addr, "\x08\x00\x07", 3) &&
            memcmp(dev->dev_addr, "\x00\xA0\x40", 3) &&
            memcmp(dev->dev_addr, "\x00\x80\x19", 3) &&
            memcmp(dev->dev_addr, "\x00\x05\x02", 3))
                bit_reverse_addr(dev->dev_addr);
        else
                return 0;

        /* If we still have what seems to be a bogus address, we'll
           look in the CAM.  The top entry should be ours. */
        /* Danger! This only works if MacOS has already initialized
           the card... */
        if (memcmp(dev->dev_addr, "\x08\x00\x07", 3) &&
            memcmp(dev->dev_addr, "\x00\xA0\x40", 3) &&
            memcmp(dev->dev_addr, "\x00\x80\x19", 3) &&
            memcmp(dev->dev_addr, "\x00\x05\x02", 3))
        {
                unsigned short val;

                printk(KERN_INFO "macsonic: PROM seems to be wrong, trying CAM entry 15\n");

                SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
                SONIC_WRITE(SONIC_CEP, 15);

                val = SONIC_READ(SONIC_CAP2);
                dev->dev_addr[5] = val >> 8;
                dev->dev_addr[4] = val & 0xff;
                val = SONIC_READ(SONIC_CAP1);
                dev->dev_addr[3] = val >> 8;
                dev->dev_addr[2] = val & 0xff;
                val = SONIC_READ(SONIC_CAP0);
                dev->dev_addr[1] = val >> 8;
                dev->dev_addr[0] = val & 0xff;

                printk(KERN_INFO "HW Address from CAM 15: %s\n",
                       print_mac(mac, dev->dev_addr));
        } else return 0;

        if (memcmp(dev->dev_addr, "\x08\x00\x07", 3) &&
            memcmp(dev->dev_addr, "\x00\xA0\x40", 3) &&
            memcmp(dev->dev_addr, "\x00\x80\x19", 3) &&
            memcmp(dev->dev_addr, "\x00\x05\x02", 3))
        {
                /*
                 * Still nonsense ... messed up someplace!
                 */
                printk(KERN_ERR "macsonic: ERROR (INVALID MAC)\n");
                return -EIO;
        } else return 0;
}

int __init mac_onboard_sonic_probe(struct net_device* dev)
{
        /* Bwahahaha */
        static int once_is_more_than_enough;
        struct sonic_local* lp = netdev_priv(dev);
        int sr;
        int commslot = 0;

        if (once_is_more_than_enough)
                return -ENODEV;
        once_is_more_than_enough = 1;

        if (!MACH_IS_MAC)
                return -ENODEV;

        if (macintosh_config->ether_type != MAC_ETHER_SONIC)
                return -ENODEV;

        printk(KERN_INFO "Checking for internal Macintosh ethernet (SONIC).. ");

        /* Bogus probing, on the models which may or may not have
           Ethernet (BTW, the Ethernet *is* always at the same
           address, and nothing else lives there, at least if Apple's
           documentation is to be believed) */
        if (macintosh_config->ident == MAC_MODEL_Q630 ||
            macintosh_config->ident == MAC_MODEL_P588 ||
            macintosh_config->ident == MAC_MODEL_P575 ||
            macintosh_config->ident == MAC_MODEL_C610) {
                unsigned long flags;
                int card_present;

                local_irq_save(flags);
                card_present = hwreg_present((void*)ONBOARD_SONIC_REGISTERS);
                local_irq_restore(flags);

                if (!card_present) {
                        printk("none.\n");
                        return -ENODEV;
                }
                commslot = 1;
        }

        printk("yes\n");

        /* Danger!  My arms are flailing wildly!  You *must* set lp->reg_offset
         * and dev->base_addr before using SONIC_READ() or SONIC_WRITE() */
        dev->base_addr = ONBOARD_SONIC_REGISTERS;
        if (via_alt_mapping)
                dev->irq = IRQ_AUTO_3;
        else
                dev->irq = IRQ_NUBUS_9;

        if (!sonic_version_printed) {
                printk(KERN_INFO "%s", version);
                sonic_version_printed = 1;
        }
        printk(KERN_INFO "%s: onboard / comm-slot SONIC at 0x%08lx\n",
               lp->device->bus_id, dev->base_addr);

        /* The PowerBook's SONIC is 16 bit always. */
        if (macintosh_config->ident == MAC_MODEL_PB520) {
                lp->reg_offset = 0;
                lp->dma_bitmode = SONIC_BITMODE16;
                sr = SONIC_READ(SONIC_SR);
        } else if (commslot) {
                /* Some of the comm-slot cards are 16 bit.  But some
                   of them are not.  The 32-bit cards use offset 2 and
                   have known revisions, we try reading the revision
                   register at offset 2, if we don't get a known revision
                   we assume 16 bit at offset 0.  */
                lp->reg_offset = 2;
                lp->dma_bitmode = SONIC_BITMODE16;

                sr = SONIC_READ(SONIC_SR);
                if (sr == 0x0004 || sr == 0x0006 || sr == 0x0100 || sr == 0x0101)
                        /* 83932 is 0x0004 or 0x0006, 83934 is 0x0100 or 0x0101 */
                        lp->dma_bitmode = SONIC_BITMODE32;
                else {
                        lp->dma_bitmode = SONIC_BITMODE16;
                        lp->reg_offset = 0;
                        sr = SONIC_READ(SONIC_SR);
                }
        } else {
                /* All onboard cards are at offset 2 with 32 bit DMA. */
                lp->reg_offset = 2;
                lp->dma_bitmode = SONIC_BITMODE32;
                sr = SONIC_READ(SONIC_SR);
        }
        printk(KERN_INFO
               "%s: revision 0x%04x, using %d bit DMA and register offset %d\n",
               lp->device->bus_id, sr, lp->dma_bitmode?32:16, lp->reg_offset);

#if 0 /* This is sometimes useful to find out how MacOS configured the card. */
        printk(KERN_INFO "%s: DCR: 0x%04x, DCR2: 0x%04x\n", lp->device->bus_id,
               SONIC_READ(SONIC_DCR) & 0xffff, SONIC_READ(SONIC_DCR2) & 0xffff);
#endif

        /* Software reset, then initialize control registers. */
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);

        SONIC_WRITE(SONIC_DCR, SONIC_DCR_EXBUS | SONIC_DCR_BMS |
                               SONIC_DCR_RFT1  | SONIC_DCR_TFT0 |
                               (lp->dma_bitmode ? SONIC_DCR_DW : 0));

        /* This *must* be written back to in order to restore the
         * extended programmable output bits, as it may not have been
         * initialised since the hardware reset. */
        SONIC_WRITE(SONIC_DCR2, 0);

        /* Clear *and* disable interrupts to be on the safe side */
        SONIC_WRITE(SONIC_IMR, 0);
        SONIC_WRITE(SONIC_ISR, 0x7fff);

        /* Now look for the MAC address. */
        if (mac_onboard_sonic_ethernet_addr(dev) != 0)
                return -ENODEV;

        /* Shared init code */
        return macsonic_init(dev);
}

int __init mac_nubus_sonic_ethernet_addr(struct net_device* dev,
                                         unsigned long prom_addr,
                                         int id)
{
        int i;
        for(i = 0; i < 6; i++)
                dev->dev_addr[i] = SONIC_READ_PROM(i);

        /* Some of the addresses are bit-reversed */
        if (id != MACSONIC_DAYNA)
                bit_reverse_addr(dev->dev_addr);

        return 0;
}

int __init macsonic_ident(struct nubus_dev* ndev)
{
        if (ndev->dr_hw == NUBUS_DRHW_ASANTE_LC &&
            ndev->dr_sw == NUBUS_DRSW_SONIC_LC)
                return MACSONIC_DAYNALINK;
        if (ndev->dr_hw == NUBUS_DRHW_SONIC &&
            ndev->dr_sw == NUBUS_DRSW_APPLE) {
                /* There has to be a better way to do this... */
                if (strstr(ndev->board->name, "DuoDock"))
                        return MACSONIC_DUODOCK;
                else
                        return MACSONIC_APPLE;
        }

        if (ndev->dr_hw == NUBUS_DRHW_SMC9194 &&
            ndev->dr_sw == NUBUS_DRSW_DAYNA)
                return MACSONIC_DAYNA;

        if (ndev->dr_hw == NUBUS_DRHW_APPLE_SONIC_LC &&
            ndev->dr_sw == 0) { /* huh? */
                return MACSONIC_APPLE16;
        }
        return -1;
}

int __init mac_nubus_sonic_probe(struct net_device* dev)
{
        static int slots;
        struct nubus_dev* ndev = NULL;
        struct sonic_local* lp = netdev_priv(dev);
        unsigned long base_addr, prom_addr;
        u16 sonic_dcr;
        int id = -1;
        int reg_offset, dma_bitmode;

        /* Find the first SONIC that hasn't been initialized already */
        while ((ndev = nubus_find_type(NUBUS_CAT_NETWORK,
                                       NUBUS_TYPE_ETHERNET, ndev)) != NULL)
        {
                /* Have we seen it already? */
                if (slots & (1<<ndev->board->slot))
                        continue;
                slots |= 1<<ndev->board->slot;

                /* Is it one of ours? */
                if ((id = macsonic_ident(ndev)) != -1)
                        break;
        }

        if (ndev == NULL)
                return -ENODEV;

        switch (id) {
        case MACSONIC_DUODOCK:
                base_addr = ndev->board->slot_addr + DUODOCK_SONIC_REGISTERS;
                prom_addr = ndev->board->slot_addr + DUODOCK_SONIC_PROM_BASE;
                sonic_dcr = SONIC_DCR_EXBUS | SONIC_DCR_RFT0 | SONIC_DCR_RFT1 |
                            SONIC_DCR_TFT0;
                reg_offset = 2;
                dma_bitmode = SONIC_BITMODE32;
                break;
        case MACSONIC_APPLE:
                base_addr = ndev->board->slot_addr + APPLE_SONIC_REGISTERS;
                prom_addr = ndev->board->slot_addr + APPLE_SONIC_PROM_BASE;
                sonic_dcr = SONIC_DCR_BMS | SONIC_DCR_RFT1 | SONIC_DCR_TFT0;
                reg_offset = 0;
                dma_bitmode = SONIC_BITMODE32;
                break;
        case MACSONIC_APPLE16:
                base_addr = ndev->board->slot_addr + APPLE_SONIC_REGISTERS;
                prom_addr = ndev->board->slot_addr + APPLE_SONIC_PROM_BASE;
                sonic_dcr = SONIC_DCR_EXBUS | SONIC_DCR_RFT1 | SONIC_DCR_TFT0 |
                            SONIC_DCR_PO1 | SONIC_DCR_BMS;
                reg_offset = 0;
                dma_bitmode = SONIC_BITMODE16;
                break;
        case MACSONIC_DAYNALINK:
                base_addr = ndev->board->slot_addr + APPLE_SONIC_REGISTERS;
                prom_addr = ndev->board->slot_addr + DAYNALINK_PROM_BASE;
                sonic_dcr = SONIC_DCR_RFT1 | SONIC_DCR_TFT0 |
                            SONIC_DCR_PO1 | SONIC_DCR_BMS;
                reg_offset = 0;
                dma_bitmode = SONIC_BITMODE16;
                break;
        case MACSONIC_DAYNA:
                base_addr = ndev->board->slot_addr + DAYNA_SONIC_REGISTERS;
                prom_addr = ndev->board->slot_addr + DAYNA_SONIC_MAC_ADDR;
                sonic_dcr = SONIC_DCR_BMS |
                            SONIC_DCR_RFT1 | SONIC_DCR_TFT0 | SONIC_DCR_PO1;
                reg_offset = 0;
                dma_bitmode = SONIC_BITMODE16;
                break;
        default:
                printk(KERN_ERR "macsonic: WTF, id is %d\n", id);
                return -ENODEV;
        }

        /* Danger!  My arms are flailing wildly!  You *must* set lp->reg_offset
         * and dev->base_addr before using SONIC_READ() or SONIC_WRITE() */
        dev->base_addr = base_addr;
        lp->reg_offset = reg_offset;
        lp->dma_bitmode = dma_bitmode;
        dev->irq = SLOT2IRQ(ndev->board->slot);

        if (!sonic_version_printed) {
                printk(KERN_INFO "%s", version);
                sonic_version_printed = 1;
        }
        printk(KERN_INFO "%s: %s in slot %X\n",
               lp->device->bus_id, ndev->board->name, ndev->board->slot);
        printk(KERN_INFO "%s: revision 0x%04x, using %d bit DMA and register offset %d\n",
               lp->device->bus_id, SONIC_READ(SONIC_SR), dma_bitmode?32:16, reg_offset);

#if 0 /* This is sometimes useful to find out how MacOS configured the card. */
        printk(KERN_INFO "%s: DCR: 0x%04x, DCR2: 0x%04x\n", lp->device->bus_id,
               SONIC_READ(SONIC_DCR) & 0xffff, SONIC_READ(SONIC_DCR2) & 0xffff);
#endif

        /* Software reset, then initialize control registers. */
        SONIC_WRITE(SONIC_CMD, SONIC_CR_RST);
        SONIC_WRITE(SONIC_DCR, sonic_dcr | (dma_bitmode ? SONIC_DCR_DW : 0));
        /* This *must* be written back to in order to restore the
         * extended programmable output bits, since it may not have been
         * initialised since the hardware reset. */
        SONIC_WRITE(SONIC_DCR2, 0);

        /* Clear *and* disable interrupts to be on the safe side */
        SONIC_WRITE(SONIC_IMR, 0);
        SONIC_WRITE(SONIC_ISR, 0x7fff);

        /* Now look for the MAC address. */
        if (mac_nubus_sonic_ethernet_addr(dev, prom_addr, id) != 0)
                return -ENODEV;

        /* Shared init code */
        return macsonic_init(dev);
}

static int __init mac_sonic_probe(struct platform_device *pdev)
{
        struct net_device *dev;
        struct sonic_local *lp;
        int err;
        DECLARE_MAC_BUF(mac);

        dev = alloc_etherdev(sizeof(struct sonic_local));
        if (!dev)
                return -ENOMEM;

        lp = netdev_priv(dev);
        lp->device = &pdev->dev;
        SET_NETDEV_DEV(dev, &pdev->dev);

        /* This will catch fatal stuff like -ENOMEM as well as success */
        err = mac_onboard_sonic_probe(dev);
        if (err == 0)
                goto found;
        if (err != -ENODEV)
                goto out;
        err = mac_nubus_sonic_probe(dev);
        if (err)
                goto out;
found:
        err = register_netdev(dev);
        if (err)
                goto out;

        printk("%s: MAC %s IRQ %d\n",
               dev->name, print_mac(mac, dev->dev_addr), dev->irq);

        return 0;

out:
        free_netdev(dev);

        return err;
}

MODULE_DESCRIPTION("Macintosh SONIC ethernet driver");
module_param(sonic_debug, int, 0);
MODULE_PARM_DESC(sonic_debug, "macsonic debug level (1-4)");

#include "sonic.c"

static int __devexit mac_sonic_device_remove (struct platform_device *pdev)
{
        struct net_device *dev = platform_get_drvdata(pdev);
        struct sonic_local* lp = netdev_priv(dev);

        unregister_netdev(dev);
        dma_free_coherent(lp->device, SIZEOF_SONIC_DESC * SONIC_BUS_SCALE(lp->dma_bitmode),
                          lp->descriptors, lp->descriptors_laddr);
        free_netdev(dev);

        return 0;
}

static struct platform_driver mac_sonic_driver = {
        .probe  = mac_sonic_probe,
        .remove = __devexit_p(mac_sonic_device_remove),
        .driver = {
                .name = mac_sonic_string,
        },
};

static int __init mac_sonic_init_module(void)
{
        int err;

        if ((err = platform_driver_register(&mac_sonic_driver))) {
                printk(KERN_ERR "Driver registration failed\n");
                return err;
        }

        mac_sonic_device = platform_device_alloc(mac_sonic_string, 0);
        if (!mac_sonic_device)
                goto out_unregister;

        if (platform_device_add(mac_sonic_device)) {
                platform_device_put(mac_sonic_device);
                mac_sonic_device = NULL;
        }

        return 0;

out_unregister:
        platform_driver_unregister(&mac_sonic_driver);

        return -ENOMEM;
}

static void __exit mac_sonic_cleanup_module(void)
{
        platform_driver_unregister(&mac_sonic_driver);

        if (mac_sonic_device) {
                platform_device_unregister(mac_sonic_device);
                mac_sonic_device = NULL;
        }
}

module_init(mac_sonic_init_module);
module_exit(mac_sonic_cleanup_module);