sk_g16.c

i386的bootloader源码grub

 *       Two different registers which share the same address, Status is
 *       read-only, Control is write-only.
 *
 * I/O Command:
 *       Any bitcombination written in here starts the transmission between
 *       Host and LANCE.
 */

typedef struct
{
	unsigned char  ram[0x3fc0];   /* 16KB dual ported ram */
	unsigned char  rom[0x0020];   /* 32Byte PROM containing 6Byte MAC */
	unsigned char  res1[0x0010];  /* reserved */
	unsigned volatile short ioreg;/* LANCE I/O Register */
	unsigned volatile char  port; /* Statusregister and Controlregister */
	unsigned char  iocom;         /* I/O Command Register */
} SK_RAM;

/* struct  */

/*
 * This is the structure for the dual ported ram. We
 * have exactly 16 320 Bytes. In here there must be:
 *
 *     - Initialize Block   (starting at a word boundary)
 *     - Receive and Transmit Descriptor Rings (quadword boundary)
 *     - Data Buffers (arbitrary boundary)
 *
 * This is because LANCE has on SK_G16 only access to the dual ported
 * RAM and nowhere else.
 */

struct SK_ram
{
    struct init_block ib;
    struct tmd tmde[TMDNUM];
    struct rmd rmde[RMDNUM];
    char tmdbuf[TMDNUM][PKT_BUF_SZ];
    char rmdbuf[RMDNUM][PKT_BUF_SZ];
};

/*
 * Structure where all necessary information is for ring buffer
 * management and statistics.
 */

struct priv
{
    struct SK_ram *ram;  /* dual ported ram structure */
    struct rmd *rmdhead; /* start of receive ring descriptors */
    struct tmd *tmdhead; /* start of transmit ring descriptors */
    int        rmdnum;   /* actual used ring descriptor */
    int        tmdnum;   /* actual transmit descriptor for transmitting data */
    int        tmdlast;  /* last sent descriptor used for error handling, etc */
    void       *rmdbufs[RMDNUM]; /* pointer to the receive buffers */
    void       *tmdbufs[TMDNUM]; /* pointer to the transmit buffers */
};

/* global variable declaration */

/* static variables */

static SK_RAM *board;  /* pointer to our memory mapped board components */
static unsigned short	ioaddr; /* base io address */
static struct priv	p_data;

/* Macros */


/* Function Prototypes */

/*
 * Device Driver functions
 * -----------------------
 * See for short explanation of each function its definitions header.
 */

static int   SK_probe1(struct nic *nic, short ioaddr1);

static void SK_reset(struct nic *nic);
static int SK_poll(struct nic *nic);
static void SK_transmit(
struct nic *nic,
const char *d,			/* Destination */
unsigned int t,			/* Type */
unsigned int s,			/* size */
const char *p);			/* Packet */
static void SK_disable(struct nic *nic);
struct nic *SK_probe(struct nic *nic, unsigned short *probe_addrs);

/*
 * LANCE Functions
 * ---------------
 */

static int SK_lance_init(struct nic *nic, unsigned short mode);
static void SK_reset_board(void);
static void SK_set_RAP(int reg_number);
static int SK_read_reg(int reg_number);
static int SK_rread_reg(void);
static void SK_write_reg(int reg_number, int value);

/*
 * Debugging functions
 * -------------------
 */

static void SK_print_pos(struct nic *nic, char *text);
static void SK_print_ram(struct nic *nic);


/**************************************************************************
RESET - Reset adapter
***************************************************************************/
static void SK_reset(struct nic *nic)
{
	/* put the card in its initial state */
	SK_lance_init(nic, MODE_NORMAL);
}

/**************************************************************************
POLL - Wait for a frame
***************************************************************************/
static int SK_poll(struct nic *nic)
{
	/* return true if there's an ethernet packet ready to read */
	struct priv *p;         /* SK_G16 private structure */
	struct rmd *rmdp;
	int csr0, rmdstat, packet_there;
    PRINTF2(("## %s: At beginning of SK_poll(). CSR0: %#hX\n",
           SK_NAME, SK_read_reg(CSR0)));

	p = nic->priv_data;
    csr0 = SK_read_reg(CSR0);      /* store register for checking */

    /*
     * Acknowledge all of the current interrupt sources, disable
     * Interrupts (INEA = 0)
     */

    SK_write_reg(CSR0, csr0 & CSR0_CLRALL);

    if (csr0 & CSR0_ERR) /* LANCE Error */
    {
	printf("%s: error: %#hX", SK_NAME, csr0);

        if (csr0 & CSR0_MISS)      /* No place to store packet ? */
        {
		printf(", Packet dropped.");
        }
	putchar('\n');
    }

    rmdp = p->rmdhead + p->rmdnum;
    packet_there = 0;
    /* As long as we own the next entry, check status and send
     * it up to higher layer
     */

    while (!( (rmdstat = rmdp->u.s.status) & RX_OWN))
    {
	/*
         * Start and end of packet must be set, because we use
	 * the ethernet maximum packet length (1518) as buffer size.
	 *
	 * Because our buffers are at maximum OFLO and BUFF errors are
	 * not to be concerned (see Data sheet)
	 */

	if ((rmdstat & (RX_STP | RX_ENP)) != (RX_STP | RX_ENP))
	{
	    /* Start of a frame > 1518 Bytes ? */

	    if (rmdstat & RX_STP)
	    {
		printf("%s: packet too long\n", SK_NAME);
	    }

	    /*
             * All other packets will be ignored until a new frame with
	     * start (RX_STP) set follows.
	     *
	     * What we do is just give descriptor free for new incoming
	     * packets.
	     */

	    rmdp->u.s.status = RX_OWN;      /* Relinquish ownership to LANCE */

	}
	else if (rmdstat & RX_ERR)          /* Receive Error ? */
	{
	    printf("%s: RX error: %#hX\n", SK_NAME, (int) rmdstat);
	    rmdp->u.s.status = RX_OWN;      /* Relinquish ownership to LANCE */
	}
	else /* We have a packet which can be queued for the upper layers */
	{

	    int len = (rmdp->mlen & 0x0fff);  /* extract message length from receive buffer */

	    /*
             * Copy data out of our receive descriptor into nic->packet.
	     *
	     * (rmdp->u.buffer & 0x00ffffff) -> get address of buffer and
	     * ignore status fields)
	     */

	    memcpy(nic->packet, (unsigned char *) (rmdp->u.buffer & 0x00ffffff), nic->packetlen = len);
	    packet_there = 1;


	    /*
             * Packet is queued and marked for processing so we
	     * free our descriptor
	     */

	    rmdp->u.s.status = RX_OWN;

	    p->rmdnum++;
	    p->rmdnum %= RMDNUM;

	    rmdp = p->rmdhead + p->rmdnum;
	}
    }
    SK_write_reg(CSR0, CSR0_INEA); /* Enable Interrupts */
	return (packet_there);
}

/**************************************************************************
TRANSMIT - Transmit a frame
***************************************************************************/
static void SK_transmit(
struct nic *nic,
const char *d,			/* Destination */
unsigned int t,			/* Type */
unsigned int s,			/* size */
const char *pack)		/* Packet */
{
	/* send the packet to destination */
    struct priv *p;         /* SK_G16 private structure */
    struct tmd *tmdp;
    short len;
    int csr0, i, tmdstat;

    PRINTF2(("## %s: At beginning of SK_transmit(). CSR0: %#hX\n",
           SK_NAME, SK_read_reg(CSR0)));
	p = nic->priv_data;
	tmdp = p->tmdhead + p->tmdnum; /* Which descriptor for transmitting */

	/* Copy data into dual ported ram */

	memcpy(&p->ram->tmdbuf[p->tmdnum][0], d, ETH_ALEN);	/* dst */
	memcpy(&p->ram->tmdbuf[p->tmdnum][ETH_ALEN], nic->node_addr, ETH_ALEN); /* src */
	p->ram->tmdbuf[p->tmdnum][ETH_ALEN + ETH_ALEN] = t >> 8;	/* type */
	p->ram->tmdbuf[p->tmdnum][ETH_ALEN + ETH_ALEN + 1] = t;	/* type */
	memcpy(&p->ram->tmdbuf[p->tmdnum][ETH_HLEN], pack, s);
	s += ETH_HLEN;
	while (s < ETH_ZLEN)	/* pad to min length */
		p->ram->tmdbuf[p->tmdnum][s++] = 0;
	p->ram->tmde[p->tmdnum].status2 = 0x0;

	/* Evaluate Packet length */
	len = ETH_ZLEN < s ? s : ETH_ZLEN;

	/* Fill in Transmit Message Descriptor */

	tmdp->blen = -len;            /* set length to transmit */

	/*
	 * Packet start and end is always set because we use the maximum
	 * packet length as buffer length.
	 * Relinquish ownership to LANCE
	 */

	tmdp->u.s.status = TX_OWN | TX_STP | TX_ENP;

	/* Start Demand Transmission */
	SK_write_reg(CSR0, CSR0_TDMD | CSR0_INEA);

    csr0 = SK_read_reg(CSR0);      /* store register for checking */

    /*
     * Acknowledge all of the current interrupt sources, disable
     * Interrupts (INEA = 0)
     */

    SK_write_reg(CSR0, csr0 & CSR0_CLRALL);

    if (csr0 & CSR0_ERR) /* LANCE Error */
    {
	printf("%s: error: %#hX", SK_NAME, csr0);

        if (csr0 & CSR0_MISS)      /* No place to store packet ? */
        {
		printf(", Packet dropped.");
        }
	putchar('\n');
    }


    /* Set next buffer */
    p->tmdlast++;
    p->tmdlast &= TMDNUM-1;

    tmdstat = tmdp->u.s.status & 0xff00; /* filter out status bits 15:08 */

    /*
     * We check status of transmitted packet.
     * see LANCE data-sheet for error explanation
     */
    if (tmdstat & TX_ERR) /* Error occurred */
    {
	printf("%s: TX error: %#hX %#hX\n", SK_NAME, (int) tmdstat,
		(int) tmdp->status2);

	if (tmdp->status2 & TX_TDR)    /* TDR problems? */
	{
	    printf("%s: tdr-problems \n", SK_NAME);
	}

        if (tmdp->status2 & TX_UFLO)   /* Underflow error ? */
        {
            /*
             * If UFLO error occurs it will turn transmitter of.
             * So we must reinit LANCE
             */

            SK_lance_init(nic, MODE_NORMAL);
        }

	tmdp->status2 = 0;             /* Clear error flags */
    }

    SK_write_reg(CSR0, CSR0_INEA); /* Enable Interrupts */

	/* Set pointer to next transmit buffer */
	p->tmdnum++;
	p->tmdnum &= TMDNUM-1;

}

/**************************************************************************
DISABLE - Turn off ethernet interface
***************************************************************************/
static void SK_disable(struct nic *nic)
{
    PRINTF(("## %s: At beginning of SK_disable(). CSR0: %#hX\n",
           SK_NAME, SK_read_reg(CSR0)));
    PRINTF(("%s: Shutting %s down CSR0 %#hX\n", SK_NAME, SK_NAME,
           (int) SK_read_reg(CSR0)));

    SK_write_reg(CSR0, CSR0_STOP); /* STOP the LANCE */
}

/**************************************************************************
PROBE - Look for an adapter, this routine's visible to the outside
***************************************************************************/
struct nic *SK_probe(struct nic *nic, unsigned short *probe_addrs)
{
	unsigned short		*p;
	static unsigned short	io_addrs[] = SK_IO_PORTS;
	/* if probe_addrs is 0, then routine can use a hardwired default */
	putchar('\n');
	nic->priv_data = &p_data;
	if (probe_addrs == 0)
		probe_addrs = io_addrs;
	for (p = probe_addrs; (ioaddr = *p) != 0; ++p)
	{
		long		offset1, offset0 = inb(ioaddr);
		if ((offset0 == SK_IDLOW) &&
		 ((offset1 = inb(ioaddr + 1)) == SK_IDHIGH))
			if (SK_probe1(nic, ioaddr) >= 0)
				break;
	}
	/* if board found */
	if (ioaddr != 0)
	{
		/* point to NIC specific routines */
		nic->reset = SK_reset;
		nic->poll = SK_poll;
		nic->transmit = SK_transmit;
		nic->disable = SK_disable;
		return nic;
	}
	/* else */
	{
		return 0;
	}