/*
 * xtsonic.c
 *
 * (C) 2001 - 2007 Tensilica Inc.
 *      Kevin Chea <kchea@yahoo.com>
 *      Marc Gauthier <marc@linux-xtensa.org>
 *      Chris Zankel <chris@zankel.net>
 *
 * (C) 1996,1998 by Thomas Bogendoerfer (tsbogend@alpha.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 onboard Sonic ethernet controller on the XT2000.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/types.h>
#include <linux/fcntl.h>
#include <linux/gfp.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/ioport.h>
#include <linux/in.h>
#include <linux/string.h>
#include <linux/delay.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/slab.h>

#include <asm/io.h>
#include <asm/pgtable.h>
#include <asm/dma.h>

static char xtsonic_string[] = "xtsonic";

extern unsigned xtboard_nvram_valid(void);
extern void xtboard_get_ether_addr(unsigned char *buf);

#include "sonic.h"

/*
 * According to the documentation for the Sonic ethernet controller,
 * EOBC should be 760 words (1520 bytes) for 32-bit applications, and,
 * as such, 2 words less than the buffer size. The value for RBSIZE
 * defined in sonic.h, however is only 1520.
 *
 * (Note that in 16-bit configurations, EOBC is 759 words (1518 bytes) and
 * RBSIZE 1520 bytes)
 */
#undef SONIC_RBSIZE
#define SONIC_RBSIZE    1524

/*
 * The chip provides 256 byte register space.
 */
#define SONIC_MEM_SIZE  0x100

/*
 * Macros to access SONIC registers
 */
#define SONIC_READ(reg) \
        (0xffff & *((volatile unsigned int *)dev->base_addr+reg))

#define SONIC_WRITE(reg,val) \
        *((volatile unsigned int *)dev->base_addr+reg) = val


/* Use 0 for production, 1 for verification, and >2 for debug */
#ifdef SONIC_DEBUG
static unsigned int sonic_debug = SONIC_DEBUG;
#else
static unsigned int sonic_debug = 1;
#endif

/*
 * We cannot use station (ethernet) address prefixes to detect the
 * sonic controller since these are board manufacturer depended.
 * So we check for known Silicon Revision IDs instead.
 */
static unsigned short known_revisions[] =
{
        0x101,                  /* SONIC 83934 */
        0xffff                  /* end of list */
};

static int xtsonic_open(struct net_device *dev)
{
        int retval;

        retval = request_irq(dev->irq, sonic_interrupt, IRQF_DISABLED,
                                "sonic", dev);
        if (retval) {
                printk(KERN_ERR "%s: unable to get IRQ %d.\n",
                       dev->name, dev->irq);
                return -EAGAIN;
        }

        retval = sonic_open(dev);
        if (retval)
                free_irq(dev->irq, dev);
        return retval;
}

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

static const struct net_device_ops xtsonic_netdev_ops = {
        .ndo_open               = xtsonic_open,
        .ndo_stop               = xtsonic_close,
        .ndo_start_xmit         = sonic_send_packet,
        .ndo_get_stats          = sonic_get_stats,
        .ndo_set_rx_mode        = sonic_multicast_list,
        .ndo_tx_timeout         = sonic_tx_timeout,
        .ndo_validate_addr      = eth_validate_addr,
        .ndo_change_mtu         = eth_change_mtu,
        .ndo_set_mac_address    = eth_mac_addr,
};

static int __init sonic_probe1(struct net_device *dev)
{
        static unsigned version_printed = 0;
        unsigned int silicon_revision;
        struct sonic_local *lp = netdev_priv(dev);
        unsigned int base_addr = dev->base_addr;
        int i;
        int err = 0;

        if (!request_mem_region(base_addr, 0x100, xtsonic_string))
                return -EBUSY;

        /*
         * get the Silicon Revision ID. If this is one of the known
         * one assume that we found a SONIC ethernet controller at
         * the expected location.
         */
        silicon_revision = SONIC_READ(SONIC_SR);
        if (sonic_debug > 1)
                printk("SONIC Silicon Revision = 0x%04x\n",silicon_revision);

        i = 0;
        while ((known_revisions[i] != 0xffff) &&
                        (known_revisions[i] != silicon_revision))
                i++;

        if (known_revisions[i] == 0xffff) {
                printk("SONIC ethernet controller not found (0x%4x)\n",
                                silicon_revision);
                return -ENODEV;
        }

        if (sonic_debug  &&  version_printed++ == 0)
                printk(version);

        /*
         * Put the sonic into software reset, then retrieve ethernet address.
         * Note: we are assuming that the boot-loader has initialized the cam.
         */
        SONIC_WRITE(SONIC_CMD,SONIC_CR_RST);
        SONIC_WRITE(SONIC_DCR,
                    SONIC_DCR_WC0|SONIC_DCR_DW|SONIC_DCR_LBR|SONIC_DCR_SBUS);
        SONIC_WRITE(SONIC_CEP,0);
        SONIC_WRITE(SONIC_IMR,0);

        SONIC_WRITE(SONIC_CMD,SONIC_CR_RST);
        SONIC_WRITE(SONIC_CEP,0);

        for (i=0; i<3; i++) {
                unsigned int val = SONIC_READ(SONIC_CAP0-i);
                dev->dev_addr[i*2] = val;
                dev->dev_addr[i*2+1] = val >> 8;
        }

        /* Initialize the device structure. */

        lp->dma_bitmode = SONIC_BITMODE32;

        /*
         *  Allocate local private descriptor areas in uncached space.
         *  The entire structure must be located within the same 64kb segment.
         *  A simple way to ensure this is to allocate twice the
         *  size of the structure -- given that the structure is
         *  much less than 64 kB, at least one of the halves of
         *  the allocated area will be contained entirely in 64 kB.
         *  We also allocate extra space for a pointer to allow freeing
         *  this structure later on (in xtsonic_cleanup_module()).
         */
        lp->descriptors =
                dma_alloc_coherent(lp->device,
                        SIZEOF_SONIC_DESC * SONIC_BUS_SCALE(lp->dma_bitmode),
                        &lp->descriptors_laddr, GFP_KERNEL);

        if (lp->descriptors == NULL) {
                printk(KERN_ERR "%s: couldn't alloc DMA memory for "
                                " descriptors.\n", dev_name(lp->device));
                err = -ENOMEM;
                goto out;
        }

        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));

        /* get the virtual dma address */

        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         = &xtsonic_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;
out:
        release_region(dev->base_addr, SONIC_MEM_SIZE);
        return err;
}


/*
 * Probe for a SONIC ethernet controller on an XT2000 board.
 * Actually probing is superfluous but we're paranoid.
 */

int __devinit xtsonic_probe(struct platform_device *pdev)
{
        struct net_device *dev;
        struct sonic_local *lp;
        struct resource *resmem, *resirq;
        int err = 0;

        if ((resmem = platform_get_resource(pdev, IORESOURCE_MEM, 0)) == NULL)
                return -ENODEV;

        if ((resirq = platform_get_resource(pdev, IORESOURCE_IRQ, 0)) == NULL)
                return -ENODEV;

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

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

        dev->base_addr = resmem->start;
        dev->irq = resirq->start;

        if ((err = sonic_probe1(dev)))
                goto out;
        if ((err = register_netdev(dev)))
                goto out1;

        printk("%s: SONIC ethernet @%08lx, MAC %pM, IRQ %d\n", dev->name,
               dev->base_addr, dev->dev_addr, dev->irq);

        return 0;

out1:
        release_region(dev->base_addr, SONIC_MEM_SIZE);
out:
        free_netdev(dev);

        return err;
}

MODULE_DESCRIPTION("Xtensa XT2000 SONIC ethernet driver");
module_param(sonic_debug, int, 0);
MODULE_PARM_DESC(sonic_debug, "xtsonic debug level (1-4)");

#include "sonic.c"

static int __devexit xtsonic_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);
        release_region (dev->base_addr, SONIC_MEM_SIZE);
        free_netdev(dev);

        return 0;
}

static struct platform_driver xtsonic_driver = {
        .probe = xtsonic_probe,
        .remove = __devexit_p(xtsonic_device_remove),
        .driver = {
                .name = xtsonic_string,
        },
};

module_platform_driver(xtsonic_driver);