/* Driver for 3COM Ethernet card (PC specific code)
 *
 * This driver is deprecated - use the loadable packet driver from the
 * Clarkson collection instead. Better yet, junk your 3C501 card and buy
 * something more reasonable.
 *
 * Copyright 1991 Phil Karn, KA9Q
 */

#define	TIMER	20000	/* Timeout on transmissions */

#include <stdio.h>
#include <dos.h>
#include "global.h"
#include "mbuf.h"
#include "enet.h"
#include "iface.h"
#include "pktdrvr.h"
#include "netuser.h"
#include "ec.h"
#include "arp.h"
#include "trace.h"
#include "pc.h"

static int ec_init __ARGS((struct iface *iface,unsigned bufsize));
static int ec_raw __ARGS((struct iface *iface,struct mbuf *bp));
static int ec_stop __ARGS((struct iface *iface));
static void getecaddr __ARGS((unsigned base,char *cp));
static void rcv_fixup __ARGS((unsigned base));
static void setecaddr __ARGS((unsigned base,char *cp));

static INTERRUPT (*Ecvecsave[EC_MAX])();
static INTERRUPT (*Ecvec[])() = {ec0vec,ec1vec,ec2vec};

struct ec Ec[EC_MAX];		/* Per-controller info */
int Nec = 0;

/* Initialize interface */
static int
ec_init(iface,bufsize)
struct iface *iface;
unsigned bufsize;	/* Maximum size of receive queue in PACKETS */
{
	register struct ec *ecp;
	register unsigned base;
	int dev;

	dev = iface->dev;
	ecp = &Ec[dev];
	base = ecp->base;
	ecp->iface = iface;

	/* Pulse IE_RESET */
 	outportb(IE_CSR(base),IE_RESET);

	/* Save old int vector */
	Ecvecsave[dev] = getirq(ecp->vec);

	/* Set interrupt vector */
	if(setirq(ecp->vec,Ecvec[dev]) == -1){
		tprintf("IRQ %u out of range\n",ecp->vec);
		return -1;
	}
	maskon(ecp->vec);	/* Enable interrupt */
	if(iface->hwaddr == NULLCHAR)
		iface->hwaddr = mallocw(EADDR_LEN);
	getecaddr(base,iface->hwaddr);
	setecaddr(base,iface->hwaddr);
	if(memcmp(iface->hwaddr,Ether_bdcst,EADDR_LEN) == 0){
		tprintf("EC address PROM contains broadcast address!!\n");
		return -1;
	}
	/* Enable DMA/interrupt request, gain control of buffer */
	outportb(IE_CSR(base),IE_RIDE|IE_SYSBFR);

	/* Enable transmit interrupts */
	outportb(EDLC_XMT(base),EDLC_16 | EDLC_JAM);

	/* Set up the receiver interrupts and flush status */
	outportb(EDLC_RCV(base),EDLC_MULTI|EDLC_GOOD|EDLC_ANY|EDLC_SHORT
	 |EDLC_DRIBBLE|EDLC_FCS|EDLC_OVER);
	inportb(EDLC_RCV(base));

	/* Start receiver */
	outportw(IE_RP(base),0);	/* Reset read pointer */
	outportb(IE_CSR(base),IE_RIDE|IE_RCVEDLC);
	return 0;
}
/* Send raw packet (caller provides header) */
static int
ec_raw(iface,bp)
struct iface *iface;	/* Pointer to interface control block */
struct mbuf *bp;		/* Data field */
{
	register struct ec *ecp;
	register unsigned base;
	register int i;
	short size;

	dump(iface,IF_TRACE_OUT,CL_ETHERNET,bp);
	iface->rawsndcnt++;
	iface->lastsent = secclock();

	ecp = &Ec[iface->dev];
	base = ecp->base;

	ecp->estats.xmit++;

	size = len_p(bp);
	/* Pad the size out to the minimum, if necessary,
	 * with junk from the last packet (nice security hole here)
	 */
	if(size < RUNT)
		size = RUNT;
	size = (size+1) & ~1;	/* round size up to next even number */

	/* Wait for transmitter ready, if necessary. IE_XMTBSY is valid
	 * only in the transmit mode, hence the initial check.
	 */
	if((inportb(IE_CSR(base)) & IE_BUFCTL) == IE_XMTEDLC){
		for(i=TIMER;(inportb(IE_CSR(base)) & IE_XMTBSY) && i != 0;i--)
			;
		if(i == 0){
			ecp->estats.timeout++;
			free_p(bp);
			return -1;
		}
	}
	ecp->size = size;
	/* Get control of the board buffer and disable receiver */
	outportb(IE_CSR(base),IE_RIDE|IE_SYSBFR);
	/* Point GP at beginning of packet */
	outportw(IE_GP(base),BFRSIZ-size);
	/* Actually load each piece with a fast assembler routine */
	while(bp != NULLBUF){
		outbuf(IE_BFR(base),bp->data,bp->cnt);
		bp = free_mbuf(bp);
	}
	/* Start transmitter */
	outportw(IE_GP(base),BFRSIZ-size);
	outportb(IE_CSR(base),IE_RIDE|IE_XMTEDLC);
	return 0;
}
/* Ethernet interrupt handler */
void
ecint(dev)
int dev;
{
	register struct ec *ecp;
	register unsigned base;
	struct mbuf *bp;
	int16 size;
	char stat;
	struct phdr phdr;

	ecp = &Ec[dev];
	base = Ec[dev].base;
	ecp->estats.intrpt++;

	/* Check for transmit jam */
	if(!(inportb(IE_CSR(base)) & IE_XMTBSY)){
		stat = inportb(EDLC_XMT(base));
		if(stat & EDLC_16){
			ecp->estats.jam16++;
			rcv_fixup(base);
		} else if(stat & EDLC_JAM){
			/* Crank counter back to beginning and restart transmit */
			ecp->estats.jam++;
			outportb(IE_CSR(base),IE_RIDE|IE_SYSBFR);
			outportw(IE_GP(base),BFRSIZ - ecp->size);
			outportb(IE_CSR(base),IE_RIDE|IE_XMTEDLC);
		}
	}
	for(;;){
		stat = inportb(EDLC_RCV(base));
		if(stat & EDLC_STALE)
			break;

		if(stat & EDLC_OVER){
			ecp->estats.over++;
			rcv_fixup(base);
			continue;
		}
		if(stat & (EDLC_SHORT | EDLC_FCS | EDLC_DRIBBLE)){
			ecp->estats.bad++;
			rcv_fixup(base);
			continue;
		}
		if(stat & EDLC_ANY){
			/* Get control of the buffer */
			outportw(IE_GP(base),0);
			outportb(IE_CSR(base),IE_RIDE|IE_SYSBFR);
		
			/* Allocate mbuf and copy the packet into it */
			size = inportw(IE_RP(base));
			if(size < RUNT || size > GIANT)
				ecp->estats.bad++;
			else if((bp = alloc_mbuf(size+sizeof(phdr))) == NULLBUF)
				ecp->estats.nomem++;
			else {
				ecp->estats.recv++;
				/* Generate descriptor header */
				phdr.iface = ecp->iface;
				phdr.type = CL_ETHERNET;
				memcpy(&bp->data[0],(char *)&phdr,sizeof(phdr));
				inbuf(IE_BFR(base),bp->data+sizeof(phdr),size);
				bp->cnt = size + sizeof(phdr);
				enqueue(&Hopper,bp);
			}
			outportb(IE_CSR(base),IE_RIDE|IE_RCVEDLC);
			outportb(IE_RP(base),0);
		}
	}
	/* Clear any spurious interrupts */
	(void)inportb(EDLC_RCV(base));
	(void)inportb(EDLC_XMT(base));
}
static void
rcv_fixup(base)
register unsigned base;
{
	outportb(IE_CSR(base),IE_RIDE|IE_SYSBFR);
	outportb(IE_CSR(base),IE_RIDE|IE_RCVEDLC);
	outportb(IE_RP(base),0);
}
/* Read Ethernet address from controller PROM */
static void
getecaddr(base,cp)
register unsigned base;
register char *cp;
{
	register int i;

	for(i=0;i<EADDR_LEN;i++){
		outportw(IE_GP(base),i);
		*cp++ = inportb(IE_SAPROM(base));
	}
}
/* Set Ethernet address on controller */
static void
setecaddr(base,cp)
register unsigned base;
register char *cp;
{
	register int i;

	for(i=0;i<EADDR_LEN;i++)
		outportb(EDLC_ADDR(base)+i,*cp++);
}
/* Shut down the Ethernet controller */
static int
ec_stop(iface)
struct iface *iface;
{
	register unsigned base;
	int dev;
	register struct ec *ecp;

	dev = iface->dev;
	ecp = &Ec[dev];
	base = ecp->base;

	/* Disable interrupt */
	maskoff(Ec[dev].vec);

	/* Restore original interrupt vector */
	setirq(ecp->vec,Ecvecsave[dev]);

	/* Pulse IE_RESET */
	outportb(IE_CSR(base),IE_RESET);
	outportb(IE_CSR(base),0);
	return 0;
}
/* Attach a 3-Com model 3C500 Ethernet controller to the system
 * argv[0]: hardware type, must be "3c500"
 * argv[1]: I/O address, e.g., "0x300"
 * argv[2]: vector, e.g., "3"
 * argv[3]: mode, must be "arpa"
 * argv[4]: interface label, e.g., "ec0"
 * argv[5]: maximum number of packets allowed on receive queue, e.g., "5"
 * argv[6]: maximum transmission unit, bytes, e.g., "1500"
 * argv[7]: IP address, optional (defaults to Ip_addr)
 */
int
ec_attach(argc,argv,p)
int argc;
char *argv[];
void *p;
{
	register struct iface *if_ec;
	int dev;

	if(Nec >= EC_MAX){
		tprintf("Too many Ethernet controllers\n");
		return -1;
	}
	if(if_lookup(argv[4]) != NULLIF){
		tprintf("Interface %s already exists\n",argv[4]);
		return -1;
	}
	dev = Nec++;
	if_ec = (struct iface *)callocw(1,sizeof(struct iface));
	if_ec->addr = Ip_addr;
	if(argc > 7)
		if_ec->addr = resolve(argv[7]);
	if(if_ec->addr == 0){
		tprintf(Noipaddr);
		free((char *)if_ec);
		return -1;
	}
	if_ec->name = strdup(argv[4]);
	if_ec->mtu = atoi(argv[6]);
	if_ec->type = CL_ETHERNET;
	if_ec->send = enet_send;
	if_ec->output = enet_output;
	if_ec->raw = ec_raw;
	if_ec->stop = ec_stop;
	if_ec->dev = dev;

	Ec[dev].base = htoi(argv[1]);
	Ec[dev].vec = htoi(argv[2]);

	if(strcmp(argv[3],"arpa") != 0){
		tprintf("Mode %s unknown for interface %s\n",
			argv[3],argv[4]);
		free(if_ec->name);
		free((char *)if_ec);
		return -1;
	}
	/* Initialize device */
	if(ec_init(if_ec,(unsigned)atoi(argv[5])) != 0){
		free(if_ec->name);
		free((char *)if_ec);
		return -1;
	}
	if_ec->next = Ifaces;
	Ifaces = if_ec;

	return 0;
}