#include "hw.h"

#include "mips.h"

#include "net.h"

#include "isa.h"

//#define DEBUG_MIPSNET_SEND

//#define DEBUG_MIPSNET_RECEIVE

//#define DEBUG_MIPSNET_DATA

//#define DEBUG_MIPSNET_IRQ

/* MIPSnet register offsets */

#define MIPSNET_DEV_ID		0x00

#define MIPSNET_BUSY		0x08

#define MIPSNET_RX_DATA_COUNT	0x0c

#define MIPSNET_TX_DATA_COUNT	0x10

#define MIPSNET_INT_CTL		0x14

# define MIPSNET_INTCTL_TXDONE		0x00000001

# define MIPSNET_INTCTL_RXDONE		0x00000002

# define MIPSNET_INTCTL_TESTBIT		0x80000000

#define MIPSNET_INTERRUPT_INFO	0x18

#define MIPSNET_RX_DATA_BUFFER	0x1c

#define MIPSNET_TX_DATA_BUFFER	0x20

#define MAX_ETH_FRAME_SIZE	1514

typedef struct MIPSnetState {

    uint32_t busy;

    uint32_t rx_count;

    uint32_t rx_read;

    uint32_t tx_count;

    uint32_t tx_written;

    uint32_t intctl;

    uint8_t rx_buffer[MAX_ETH_FRAME_SIZE];

    uint8_t tx_buffer[MAX_ETH_FRAME_SIZE];

    qemu_irq irq;

    VLANClientState *vc;

    NICInfo *nd;

} MIPSnetState;

static void mipsnet_reset(MIPSnetState *s)

{

    s->busy = 1;

    s->rx_count = 0;

    s->rx_read = 0;

    s->tx_count = 0;

    s->tx_written = 0;

    s->intctl = 0;

    memset(s->rx_buffer, 0, MAX_ETH_FRAME_SIZE);

    memset(s->tx_buffer, 0, MAX_ETH_FRAME_SIZE);

}

static void mipsnet_update_irq(MIPSnetState *s)

{

    int isr = !!s->intctl;

#ifdef DEBUG_MIPSNET_IRQ

    printf("mipsnet: Set IRQ to %d (%02x)\n", isr, s->intctl);

#endif

    qemu_set_irq(s->irq, isr);

}

static int mipsnet_buffer_full(MIPSnetState *s)

{

    if (s->rx_count >= MAX_ETH_FRAME_SIZE)

        return 1;

    return 0;

}

static int mipsnet_can_receive(void *opaque)

{

    MIPSnetState *s = opaque;

    if (s->busy)

        return 0;

    return !mipsnet_buffer_full(s);

}

static void mipsnet_receive(void *opaque, const uint8_t *buf, int size)

{

    MIPSnetState *s = opaque;

#ifdef DEBUG_MIPSNET_RECEIVE

    printf("mipsnet: receiving len=%d\n", size);

#endif

    if (!mipsnet_can_receive(opaque))

        return;

    s->busy = 1;

    /* Just accept everything. */

    /* Write packet data. */

    memcpy(s->rx_buffer, buf, size);

    s->rx_count = size;

    s->rx_read = 0;

    /* Now we can signal we have received something. */

    s->intctl |= MIPSNET_INTCTL_RXDONE;

    mipsnet_update_irq(s);

}

static uint32_t mipsnet_ioport_read(void *opaque, uint32_t addr)

{

    MIPSnetState *s = opaque;

    int ret = 0;

    addr &= 0x3f;

    switch (addr) {

    case MIPSNET_DEV_ID:

	ret = be32_to_cpu(0x4d495053);		/* MIPS */

        break;

    case MIPSNET_DEV_ID + 4:

	ret = be32_to_cpu(0x4e455430);		/* NET0 */

        break;

    case MIPSNET_BUSY:

	ret = s->busy;

        break;

    case MIPSNET_RX_DATA_COUNT:

	ret = s->rx_count;

        break;

    case MIPSNET_TX_DATA_COUNT:

	ret = s->tx_count;

        break;

    case MIPSNET_INT_CTL:

	ret = s->intctl;

        s->intctl &= ~MIPSNET_INTCTL_TESTBIT;

        break;

    case MIPSNET_INTERRUPT_INFO:

        /* XXX: This seems to be a per-VPE interrupt number. */

	ret = 0;

        break;

    case MIPSNET_RX_DATA_BUFFER:

        if (s->rx_count) {

            s->rx_count--;

            ret = s->rx_buffer[s->rx_read++];

        }

        break;

    /* Reads as zero. */

    case MIPSNET_TX_DATA_BUFFER:

    default:

        break;

    }

#ifdef DEBUG_MIPSNET_DATA

    printf("mipsnet: read addr=0x%02x val=0x%02x\n", addr, ret);

#endif

    return ret;

}

static void mipsnet_ioport_write(void *opaque, uint32_t addr, uint32_t val)

{

    MIPSnetState *s = opaque;

    addr &= 0x3f;

#ifdef DEBUG_MIPSNET_DATA

    printf("mipsnet: write addr=0x%02x val=0x%02x\n", addr, val);

#endif

    switch (addr) {

    case MIPSNET_TX_DATA_COUNT:

	s->tx_count = (val <= MAX_ETH_FRAME_SIZE) ? val : 0;

        s->tx_written = 0;

        break;

    case MIPSNET_INT_CTL:

        if (val & MIPSNET_INTCTL_TXDONE) {

            s->intctl &= ~MIPSNET_INTCTL_TXDONE;

        } else if (val & MIPSNET_INTCTL_RXDONE) {

            s->intctl &= ~MIPSNET_INTCTL_RXDONE;

        } else if (val & MIPSNET_INTCTL_TESTBIT) {

            mipsnet_reset(s);

            s->intctl |= MIPSNET_INTCTL_TESTBIT;

        } else if (!val) {

            /* ACK testbit interrupt, flag was cleared on read. */

        }

        s->busy = !!s->intctl;

        mipsnet_update_irq(s);

        break;

    case MIPSNET_TX_DATA_BUFFER:

        s->tx_buffer[s->tx_written++] = val;

        if (s->tx_written == s->tx_count) {

            /* Send buffer. */

#ifdef DEBUG_MIPSNET_SEND

            printf("mipsnet: sending len=%d\n", s->tx_count);

#endif

            qemu_send_packet(s->vc, s->tx_buffer, s->tx_count);

            s->tx_count = s->tx_written = 0;

            s->intctl |= MIPSNET_INTCTL_TXDONE;

            s->busy = 1;

            mipsnet_update_irq(s);

        }

        break;

    /* Read-only registers */

    case MIPSNET_DEV_ID:

    case MIPSNET_BUSY:

    case MIPSNET_RX_DATA_COUNT:

    case MIPSNET_INTERRUPT_INFO:

    case MIPSNET_RX_DATA_BUFFER:

    default:

        break;

    }

}

static void mipsnet_save(QEMUFile *f, void *opaque)

{

    MIPSnetState *s = opaque;

    qemu_put_be32s(f, &s->busy);

    qemu_put_be32s(f, &s->rx_count);

    qemu_put_be32s(f, &s->rx_read);

    qemu_put_be32s(f, &s->tx_count);

    qemu_put_be32s(f, &s->tx_written);

    qemu_put_be32s(f, &s->intctl);

    qemu_put_buffer(f, s->rx_buffer, MAX_ETH_FRAME_SIZE);

    qemu_put_buffer(f, s->tx_buffer, MAX_ETH_FRAME_SIZE);

}

static int mipsnet_load(QEMUFile *f, void *opaque, int version_id)

{

    MIPSnetState *s = opaque;

    if (version_id > 0)

        return -EINVAL;

    qemu_get_be32s(f, &s->busy);

    qemu_get_be32s(f, &s->rx_count);

    qemu_get_be32s(f, &s->rx_read);

    qemu_get_be32s(f, &s->tx_count);

    qemu_get_be32s(f, &s->tx_written);

    qemu_get_be32s(f, &s->intctl);

    qemu_get_buffer(f, s->rx_buffer, MAX_ETH_FRAME_SIZE);

    qemu_get_buffer(f, s->tx_buffer, MAX_ETH_FRAME_SIZE);

    return 0;

}

void mipsnet_init (int base, qemu_irq irq, NICInfo *nd)

{

    MIPSnetState *s;

    s = qemu_mallocz(sizeof(MIPSnetState));

    if (!s)

        return;

    register_ioport_write(base, 36, 1, mipsnet_ioport_write, s);

    register_ioport_read(base, 36, 1, mipsnet_ioport_read, s);

    register_ioport_write(base, 36, 2, mipsnet_ioport_write, s);

    register_ioport_read(base, 36, 2, mipsnet_ioport_read, s);

    register_ioport_write(base, 36, 4, mipsnet_ioport_write, s);

    register_ioport_read(base, 36, 4, mipsnet_ioport_read, s);

    s->irq = irq;

    s->nd = nd;

    if (nd && nd->vlan) {

        s->vc = qemu_new_vlan_client(nd->vlan, mipsnet_receive,

                                     mipsnet_can_receive, s);

    } else {

        s->vc = NULL;

    }

    snprintf(s->vc->info_str, sizeof(s->vc->info_str),

             "mipsnet macaddr=%02x:%02x:%02x:%02x:%02x:%02x",

              s->nd->macaddr[0],

              s->nd->macaddr[1],

              s->nd->macaddr[2],

              s->nd->macaddr[3],

              s->nd->macaddr[4],

              s->nd->macaddr[5]);

    mipsnet_reset(s);

    register_savevm("mipsnet", 0, 0, mipsnet_save, mipsnet_load, s);

}