/*
 * QEMU Lance emulation
 * 
 * Copyright (c) 2003-2005 Fabrice Bellard
 * 
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */
#include "vl.h"

/* debug LANCE card */
//#define DEBUG_LANCE

#ifdef DEBUG_LANCE
#define DPRINTF(fmt, args...) \
do { printf("LANCE: " fmt , ##args); } while (0)
#else
#define DPRINTF(fmt, args...)
#endif

#ifndef LANCE_LOG_TX_BUFFERS
#define LANCE_LOG_TX_BUFFERS 4
#define LANCE_LOG_RX_BUFFERS 4
#endif

#define LE_CSR0 0
#define LE_CSR1 1
#define LE_CSR2 2
#define LE_CSR3 3
#define LE_NREGS (LE_CSR3 + 1)
#define LE_MAXREG LE_CSR3

#define LE_RDP  0
#define LE_RAP  1

#define LE_MO_PROM      0x8000  /* Enable promiscuous mode */

#define	LE_C0_ERR	0x8000  /* Error: set if BAB, SQE, MISS or ME is set */
#define	LE_C0_BABL	0x4000  /* BAB:  Babble: tx timeout. */
#define	LE_C0_CERR	0x2000  /* SQE:  Signal quality error */
#define	LE_C0_MISS	0x1000  /* MISS: Missed a packet */
#define	LE_C0_MERR	0x0800  /* ME:   Memory error */
#define	LE_C0_RINT	0x0400  /* Received interrupt */
#define	LE_C0_TINT	0x0200  /* Transmitter Interrupt */
#define	LE_C0_IDON	0x0100  /* IFIN: Init finished. */
#define	LE_C0_INTR	0x0080  /* Interrupt or error */
#define	LE_C0_INEA	0x0040  /* Interrupt enable */
#define	LE_C0_RXON	0x0020  /* Receiver on */
#define	LE_C0_TXON	0x0010  /* Transmitter on */
#define	LE_C0_TDMD	0x0008  /* Transmitter demand */
#define	LE_C0_STOP	0x0004  /* Stop the card */
#define	LE_C0_STRT	0x0002  /* Start the card */
#define	LE_C0_INIT	0x0001  /* Init the card */

#define	LE_C3_BSWP	0x4     /* SWAP */
#define	LE_C3_ACON	0x2     /* ALE Control */
#define	LE_C3_BCON	0x1     /* Byte control */

/* Receive message descriptor 1 */
#define LE_R1_OWN       0x80    /* Who owns the entry */
#define LE_R1_ERR       0x40    /* Error: if FRA, OFL, CRC or BUF is set */
#define LE_R1_FRA       0x20    /* FRA: Frame error */
#define LE_R1_OFL       0x10    /* OFL: Frame overflow */
#define LE_R1_CRC       0x08    /* CRC error */
#define LE_R1_BUF       0x04    /* BUF: Buffer error */
#define LE_R1_SOP       0x02    /* Start of packet */
#define LE_R1_EOP       0x01    /* End of packet */
#define LE_R1_POK       0x03    /* Packet is complete: SOP + EOP */

#define LE_T1_OWN       0x80    /* Lance owns the packet */
#define LE_T1_ERR       0x40    /* Error summary */
#define LE_T1_EMORE     0x10    /* Error: more than one retry needed */
#define LE_T1_EONE      0x08    /* Error: one retry needed */
#define LE_T1_EDEF      0x04    /* Error: deferred */
#define LE_T1_SOP       0x02    /* Start of packet */
#define LE_T1_EOP       0x01    /* End of packet */
#define LE_T1_POK	0x03    /* Packet is complete: SOP + EOP */

#define LE_T3_BUF       0x8000  /* Buffer error */
#define LE_T3_UFL       0x4000  /* Error underflow */
#define LE_T3_LCOL      0x1000  /* Error late collision */
#define LE_T3_CLOS      0x0800  /* Error carrier loss */
#define LE_T3_RTY       0x0400  /* Error retry */
#define LE_T3_TDR       0x03ff  /* Time Domain Reflectometry counter */

#define TX_RING_SIZE			(1 << (LANCE_LOG_TX_BUFFERS))
#define TX_RING_MOD_MASK		(TX_RING_SIZE - 1)
#define TX_RING_LEN_BITS		((LANCE_LOG_TX_BUFFERS) << 29)

#define RX_RING_SIZE			(1 << (LANCE_LOG_RX_BUFFERS))
#define RX_RING_MOD_MASK		(RX_RING_SIZE - 1)
#define RX_RING_LEN_BITS		((LANCE_LOG_RX_BUFFERS) << 29)

#define PKT_BUF_SZ		1544
#define RX_BUFF_SIZE            PKT_BUF_SZ
#define TX_BUFF_SIZE            PKT_BUF_SZ

struct lance_rx_desc {
    unsigned short rmd0;        /* low address of packet */
    unsigned char rmd1_bits;    /* descriptor bits */
    unsigned char rmd1_hadr;    /* high address of packet */
    short length;               /* This length is 2s complement (negative)!
                                 * Buffer length
                                 */
    unsigned short mblength;    /* This is the actual number of bytes received */
};

struct lance_tx_desc {
    unsigned short tmd0;        /* low address of packet */
    unsigned char tmd1_bits;    /* descriptor bits */
    unsigned char tmd1_hadr;    /* high address of packet */
    short length;               /* Length is 2s complement (negative)! */
    unsigned short misc;
};

/* The LANCE initialization block, described in databook. */
/* On the Sparc, this block should be on a DMA region     */
struct lance_init_block {
    unsigned short mode;        /* Pre-set mode (reg. 15) */
    unsigned char phys_addr[6]; /* Physical ethernet address */
    unsigned filter[2];         /* Multicast filter. */

    /* Receive and transmit ring base, along with extra bits. */
    unsigned short rx_ptr;      /* receive descriptor addr */
    unsigned short rx_len;      /* receive len and high addr */
    unsigned short tx_ptr;      /* transmit descriptor addr */
    unsigned short tx_len;      /* transmit len and high addr */

    /* The Tx and Rx ring entries must aligned on 8-byte boundaries. */
    struct lance_rx_desc brx_ring[RX_RING_SIZE];
    struct lance_tx_desc btx_ring[TX_RING_SIZE];

    char tx_buf[TX_RING_SIZE][TX_BUFF_SIZE];
    char pad[2];                /* align rx_buf for copy_and_sum(). */
    char rx_buf[RX_RING_SIZE][RX_BUFF_SIZE];
};

#define LEDMA_REGS 4
#define LEDMA_MAXADDR (LEDMA_REGS * 4 - 1)

typedef struct LANCEState {
    VLANClientState *vc;
    uint8_t macaddr[6];         /* init mac address */
    uint32_t leptr;
    uint16_t addr;
    uint16_t regs[LE_NREGS];
    uint8_t phys[6];            /* mac address */
    int irq;
    unsigned int rxptr, txptr;
    uint32_t ledmaregs[LEDMA_REGS];
} LANCEState;

static void lance_send(void *opaque);

static void lance_reset(void *opaque)
{
    LANCEState *s = opaque;
    memcpy(s->phys, s->macaddr, 6);
    s->rxptr = 0;
    s->txptr = 0;
    memset(s->regs, 0, LE_NREGS * 2);
    s->regs[LE_CSR0] = LE_C0_STOP;
    memset(s->ledmaregs, 0, LEDMA_REGS * 4);
}

static uint32_t lance_mem_readw(void *opaque, target_phys_addr_t addr)
{
    LANCEState *s = opaque;
    uint32_t saddr;

    saddr = addr & LE_MAXREG;
    switch (saddr >> 1) {
    case LE_RDP:
        DPRINTF("read dreg[%d] = %4.4x\n", s->addr, s->regs[s->addr]);
        return s->regs[s->addr];
    case LE_RAP:
        DPRINTF("read areg = %4.4x\n", s->addr);
        return s->addr;
    default:
        DPRINTF("read unknown(%d)\n", saddr >> 1);
        break;
    }
    return 0;
}

static void lance_mem_writew(void *opaque, target_phys_addr_t addr,
                             uint32_t val)
{
    LANCEState *s = opaque;
    uint32_t saddr;
    uint16_t reg;

    saddr = addr & LE_MAXREG;
    switch (saddr >> 1) {
    case LE_RDP:
        DPRINTF("write dreg[%d] = %4.4x\n", s->addr, val);
        switch (s->addr) {
        case LE_CSR0:
            if (val & LE_C0_STOP) {
                s->regs[LE_CSR0] = LE_C0_STOP;
                break;
            }

            reg = s->regs[LE_CSR0];

            // 1 = clear for some bits
            reg &= ~(val & 0x7f00);

            // generated bits
            reg &= ~(LE_C0_ERR | LE_C0_INTR);
            if (reg & 0x7100)
                reg |= LE_C0_ERR;
            if (reg & 0x7f00)
                reg |= LE_C0_INTR;

            // direct bit
            reg &= ~LE_C0_INEA;
            reg |= val & LE_C0_INEA;

            // exclusive bits
            if (val & LE_C0_INIT) {
                reg |= LE_C0_IDON | LE_C0_INIT;
                reg &= ~LE_C0_STOP;
            } else if (val & LE_C0_STRT) {
                reg |= LE_C0_STRT | LE_C0_RXON | LE_C0_TXON;
                reg &= ~LE_C0_STOP;
            }

            s->regs[LE_CSR0] = reg;
            break;
        case LE_CSR1:
            s->leptr = (s->leptr & 0xffff0000) | (val & 0xffff);
            s->regs[s->addr] = val;
            break;
        case LE_CSR2:
            s->leptr = (s->leptr & 0xffff) | ((val & 0xffff) << 16);
            s->regs[s->addr] = val;
            break;
        case LE_CSR3:
            s->regs[s->addr] = val;
            break;
        }
        break;
    case LE_RAP:
        DPRINTF("write areg = %4.4x\n", val);
        if (val < LE_NREGS)
            s->addr = val;
        break;
    default:
        DPRINTF("write unknown(%d) = %4.4x\n", saddr >> 1, val);
        break;
    }
    lance_send(s);
}

static CPUReadMemoryFunc *lance_mem_read[3] = {
    lance_mem_readw,
    lance_mem_readw,
    lance_mem_readw,
};

static CPUWriteMemoryFunc *lance_mem_write[3] = {
    lance_mem_writew,
    lance_mem_writew,
    lance_mem_writew,
};


#define MIN_BUF_SIZE 60

static int lance_can_receive(void *opaque)
{
    return 1;
}

static void lance_receive(void *opaque, const uint8_t * buf, int size)
{
    LANCEState *s = opaque;
    uint32_t dmaptr = s->leptr + s->ledmaregs[3];
    struct lance_init_block *ib;
    unsigned int i, old_rxptr;
    uint16_t temp16;
    uint8_t temp8;

    DPRINTF("receive size %d\n", size);
    if ((s->regs[LE_CSR0] & LE_C0_STOP) == LE_C0_STOP)
        return;

    ib = (void *) iommu_translate(dmaptr);

    old_rxptr = s->rxptr;
    for (i = s->rxptr; i != ((old_rxptr - 1) & RX_RING_MOD_MASK);
         i = (i + 1) & RX_RING_MOD_MASK) {
        cpu_physical_memory_read((uint32_t) & ib->brx_ring[i].rmd1_bits,
                                 (void *) &temp8, 1);
        if (temp8 == (LE_R1_OWN)) {
            s->rxptr = (s->rxptr + 1) & RX_RING_MOD_MASK;
            temp16 = size + 4;
            bswap16s(&temp16);
            cpu_physical_memory_write((uint32_t) & ib->brx_ring[i].
                                      mblength, (void *) &temp16, 2);
            cpu_physical_memory_write((uint32_t) & ib->rx_buf[i], buf,
                                      size);
            temp8 = LE_R1_POK;
            cpu_physical_memory_write((uint32_t) & ib->brx_ring[i].
                                      rmd1_bits, (void *) &temp8, 1);
            s->regs[LE_CSR0] |= LE_C0_RINT | LE_C0_INTR;
            if (s->regs[LE_CSR0] & LE_C0_INEA)
                pic_set_irq(s->irq, 1);
            DPRINTF("got packet, len %d\n", size);
            return;
        }
    }
}

static void lance_send(void *opaque)
{
    LANCEState *s = opaque;
    uint32_t dmaptr = s->leptr + s->ledmaregs[3];
    struct lance_init_block *ib;
    unsigned int i, old_txptr;
    uint16_t temp16;
    uint8_t temp8;
    char pkt_buf[PKT_BUF_SZ];

    DPRINTF("sending packet? (csr0 %4.4x)\n", s->regs[LE_CSR0]);
    if ((s->regs[LE_CSR0] & LE_C0_STOP) == LE_C0_STOP)
        return;

    ib = (void *) iommu_translate(dmaptr);

    DPRINTF("sending packet? (dmaptr %8.8x) (ib %p) (btx_ring %p)\n",
            dmaptr, ib, &ib->btx_ring);
    old_txptr = s->txptr;
    for (i = s->txptr; i != ((old_txptr - 1) & TX_RING_MOD_MASK);
         i = (i + 1) & TX_RING_MOD_MASK) {
        cpu_physical_memory_read((uint32_t) & ib->btx_ring[i].tmd1_bits,
                                 (void *) &temp8, 1);
        if (temp8 == (LE_T1_POK | LE_T1_OWN)) {
            cpu_physical_memory_read((uint32_t) & ib->btx_ring[i].length,
                                     (void *) &temp16, 2);
            bswap16s(&temp16);
            temp16 = (~temp16) + 1;
            cpu_physical_memory_read((uint32_t) & ib->tx_buf[i], pkt_buf,
                                     temp16);
            DPRINTF("sending packet, len %d\n", temp16);
            qemu_send_packet(s->vc, pkt_buf, temp16);
            temp8 = LE_T1_POK;
            cpu_physical_memory_write((uint32_t) & ib->btx_ring[i].
                                      tmd1_bits, (void *) &temp8, 1);
            s->txptr = (s->txptr + 1) & TX_RING_MOD_MASK;
            s->regs[LE_CSR0] |= LE_C0_TINT | LE_C0_INTR;
        }
    }
    if ((s->regs[LE_CSR0] & LE_C0_INTR) && (s->regs[LE_CSR0] & LE_C0_INEA))
        pic_set_irq(s->irq, 1);
}

static uint32_t ledma_mem_readl(void *opaque, target_phys_addr_t addr)
{
    LANCEState *s = opaque;
    uint32_t saddr;

    saddr = (addr & LEDMA_MAXADDR) >> 2;
    return s->ledmaregs[saddr];
}

static void ledma_mem_writel(void *opaque, target_phys_addr_t addr,
                             uint32_t val)
{
    LANCEState *s = opaque;
    uint32_t saddr;

    saddr = (addr & LEDMA_MAXADDR) >> 2;
    s->ledmaregs[saddr] = val;
}

static CPUReadMemoryFunc *ledma_mem_read[3] = {
    ledma_mem_readl,
    ledma_mem_readl,
    ledma_mem_readl,
};

static CPUWriteMemoryFunc *ledma_mem_write[3] = {
    ledma_mem_writel,
    ledma_mem_writel,
    ledma_mem_writel,
};

static void lance_save(QEMUFile * f, void *opaque)
{
    LANCEState *s = opaque;
    int i;

    qemu_put_be32s(f, &s->leptr);
    qemu_put_be16s(f, &s->addr);
    for (i = 0; i < LE_NREGS; i++)
        qemu_put_be16s(f, &s->regs[i]);
    qemu_put_buffer(f, s->phys, 6);
    qemu_put_be32s(f, &s->irq);
    for (i = 0; i < LEDMA_REGS; i++)
        qemu_put_be32s(f, &s->ledmaregs[i]);
}

static int lance_load(QEMUFile * f, void *opaque, int version_id)
{
    LANCEState *s = opaque;
    int i;

    if (version_id != 1)
        return -EINVAL;

    qemu_get_be32s(f, &s->leptr);
    qemu_get_be16s(f, &s->addr);
    for (i = 0; i < LE_NREGS; i++)
        qemu_get_be16s(f, &s->regs[i]);
    qemu_get_buffer(f, s->phys, 6);
    qemu_get_be32s(f, &s->irq);
    for (i = 0; i < LEDMA_REGS; i++)
        qemu_get_be32s(f, &s->ledmaregs[i]);
    return 0;
}

void lance_init(NICInfo * nd, int irq, uint32_t leaddr, uint32_t ledaddr)
{
    LANCEState *s;
    int lance_io_memory, ledma_io_memory;

    s = qemu_mallocz(sizeof(LANCEState));
    if (!s)
        return;

    s->irq = irq;

    lance_io_memory =
        cpu_register_io_memory(0, lance_mem_read, lance_mem_write, s);
    cpu_register_physical_memory(leaddr, 4, lance_io_memory);

    ledma_io_memory =
        cpu_register_io_memory(0, ledma_mem_read, ledma_mem_write, s);
    cpu_register_physical_memory(ledaddr, 16, ledma_io_memory);

    memcpy(s->macaddr, nd->macaddr, 6);

    lance_reset(s);

    s->vc =
        qemu_new_vlan_client(nd->vlan, lance_receive, lance_can_receive,
                             s);

    snprintf(s->vc->info_str, sizeof(s->vc->info_str),
             "lance macaddr=%02x:%02x:%02x:%02x:%02x:%02x",
             s->macaddr[0],
             s->macaddr[1],
             s->macaddr[2], s->macaddr[3], s->macaddr[4], s->macaddr[5]);

    register_savevm("lance", leaddr, 1, lance_save, lance_load, s);
    qemu_register_reset(lance_reset, s);
}