/*
 * 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;

/* 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;
}

static const struct net_device_ops macsonic_netdev_ops = {
	.ndo_open		= macsonic_open,
	.ndo_stop		= macsonic_close,
	.ndo_start_xmit		= sonic_send_packet,
	.ndo_set_multicast_list	= sonic_multicast_list,
	.ndo_tx_timeout		= sonic_tx_timeout,
	.ndo_get_stats		= sonic_get_stats,
	.ndo_validate_addr	= eth_validate_addr,
	.ndo_change_mtu		= eth_change_mtu,
	.ndo_set_mac_address	= eth_mac_addr,
};

static 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",
		       dev_name(lp->device));
		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->netdev_ops = &macsonic_netdev_ops;
	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;
}

static 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;

	/* 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: %pM\n",
		       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;
}

static 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",
	       dev_name(lp->device), 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",
	       dev_name(lp->device), 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", dev_name(lp->device),
	       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);
}

static 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;
}

static 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;
}

static 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",
	       dev_name(lp->device), ndev->board->name, ndev->board->slot);
	printk(KERN_INFO "%s: revision 0x%04x, using %d bit DMA and register offset %d\n",
	       dev_name(lp->device), 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", dev_name(lp->device),
	       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;

	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 %pM IRQ %d\n", dev->name, 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);