ibmlana.c

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/* 
net-3-driver for the IBM LAN Adapter/A

This is an extension to the Linux operating system, and is covered by the
same Gnu Public License that covers that work.

Copyright 1999 by Alfred Arnold ([e-mail], [e-mail])

This driver is based both on the SK_MCA driver, which is itself based on the
SK_G16 and 3C523 driver.

paper sources:
  'PC Hardware: Aufbau, Funktionsweise, Programmierung' by 
  Hans-Peter Messmer for the basic Microchannel stuff
  
  'Linux Geraetetreiber' by Allesandro Rubini, Kalle Dalheimer
  for help on Ethernet driver programming

  'DP83934CVUL-20/25 MHz SONIC-T Ethernet Controller Datasheet' by National
  Semiconductor for info on the MAC chip

  'LAN Technical Reference Ethernet Adapter Interface Version 1 Release 1.0
   Document Number SC30-3661-00' by IBM for info on the adapter itself

  Also see http://www.natsemi.com/

special acknowledgements to:
  - Bob Eager for helping me out with documentation from IBM
  - Jim Shorney for his endless patience with me while I was using 
    him as a beta tester to trace down the address filter bug ;-)

  Missing things:

  -> set debug level via ioctl instead of compile-time switches
  -> I didn't follow the development of the 2.1.x kernels, so my
     assumptions about which things changed with which kernel version 
     are probably nonsense

History:
  Nov 6th, 1999
  	startup from SK_MCA driver
  Dec 6th, 1999
	finally got docs about the card.  A big thank you to Bob Eager!
  Dec 12th, 1999
	first packet received
  Dec 13th, 1999
	recv queue done, tcpdump works
  Dec 15th, 1999
	transmission part works
  Dec 28th, 1999
	added usage of the isa_functions for Linux 2.3 .  Things should
	still work with 2.0.x....
  Jan 28th, 2000
	in Linux 2.2.13, the version.h file mysteriously didn't get
	included.  Added a workaround for this.  Futhermore, it now
	not only compiles as a modules ;-)
  Jan 30th, 2000
	newer kernels automatically probe more than one board, so the
	'startslot' as a variable is also needed here
  Apr 12th, 2000
	the interrupt mask register is not set 'hard' instead of individually
	setting registers, since this seems to set bits that shouldn't be
	set
  May 21st, 2000
	reset interrupt status immediately after CAM load
	add a recovery delay after releasing the chip's reset line
  May 24th, 2000
	finally found the bug in the address filter setup - damned signed
        chars!
  June 1st, 2000
	corrected version codes, added support for the latest 2.3 changes

 *************************************************************************/

#include <linux/version.h>
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/malloc.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/time.h>
#include <linux/mca.h>
#include <asm/processor.h>
#include <asm/bitops.h>
#include <asm/io.h>

#include <linux/module.h>

#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/skbuff.h>

#define _IBM_LANA_DRIVER_
#include "ibmlana.h"

#undef DEBUG

/* ------------------------------------------------------------------------
 * global static data - not more since we can handle multiple boards and
 * have to pack all state info into the device struct!
 * ------------------------------------------------------------------------ */

static char *MediaNames[Media_Count] =
    { "10BaseT", "10Base5", "Unknown", "10Base2" };

/* ------------------------------------------------------------------------
 * private subfunctions
 * ------------------------------------------------------------------------ */

#ifdef DEBUG
  /* dump all registers */

static void dumpregs(struct IBMLANA_NETDEV *dev)
{
	int z;

	for (z = 0; z < 160; z += 2) {
		if (!(z & 15))
			printk("REGS: %04x:", z);
		printk(" %04x", inw(dev->base_addr + z));
		if ((z & 15) == 14)
			printk("\n");
	}
}

/* dump parts of shared memory - only needed during debugging */

static void dumpmem(struct IBMLANA_NETDEV *dev, u32 start, u32 len)
{
	int z;

	printk("Address %04x:\n", start);
	for (z = 0; z < len; z++) {
		if ((z & 15) == 0)
			printk("%04x:", z);
		printk(" %02x", IBMLANA_READB(dev->mem_start + start + z));
		if ((z & 15) == 15)
			printk("\n");
	}
	if ((z & 15) != 0)
		printk("\n");
}

/* print exact time - ditto */

static void PrTime(void)
{
	struct timeval tv;

	do_gettimeofday(&tv);
	printk("%9d:%06d: ", (int) tv.tv_sec, (int) tv.tv_usec);
}
#endif				/* DEBUG */

/* deduce resources out of POS registers */

static void getaddrs(int slot, int *base, int *memlen, int *iobase,
		     int *irq, ibmlana_medium * medium)
{
	u_char pos0, pos1;

	pos0 = mca_read_stored_pos(slot, 2);
	pos1 = mca_read_stored_pos(slot, 3);

	*base = 0xc0000 + ((pos1 & 0xf0) << 9);
	*memlen = (pos1 & 0x01) ? 0x8000 : 0x4000;
	*iobase = (pos0 & 0xe0) << 7;
	switch (pos0 & 0x06) {
	case 0:
		*irq = 5;
		break;
	case 2:
		*irq = 15;
		break;
	case 4:
		*irq = 10;
		break;
	case 6:
		*irq = 11;
		break;
	}
	*medium = (pos0 & 0x18) >> 3;
}

/* wait on register value with mask and timeout */

static int wait_timeout(struct IBMLANA_NETDEV *dev, int regoffs, u16 mask,
			u16 value, int timeout)
{
	unsigned long fin = jiffies + timeout;

	while (jiffies != fin)
		if ((inw(dev->base_addr + regoffs) & mask) == value)
			return 1;

	return 0;
}


/* reset the whole board */

static void ResetBoard(struct IBMLANA_NETDEV *dev)
{
	unsigned char bcmval;

	/* read original board control value */

	bcmval = inb(dev->base_addr + BCMREG);

	/* set reset bit for a while */

	bcmval |= BCMREG_RESET;
	outb(bcmval, dev->base_addr + BCMREG);
	udelay(10);
	bcmval &= ~BCMREG_RESET;
	outb(bcmval, dev->base_addr + BCMREG);

	/* switch over to RAM again */

	bcmval |= BCMREG_RAMEN | BCMREG_RAMWIN;
	outb(bcmval, dev->base_addr + BCMREG);
}

/* calculate RAM layout & set up descriptors in RAM */

static void InitDscrs(struct IBMLANA_NETDEV *dev)
{
	ibmlana_priv *priv = (ibmlana_priv *) dev->priv;
	u32 addr, baddr, raddr;
	int z;
	tda_t tda;
	rda_t rda;
	rra_t rra;

	/* initialize RAM */

	IBMLANA_SETIO(dev->mem_start, 0xaa,
		      dev->mem_start - dev->mem_start);

	/* setup n TX descriptors - independent of RAM size */

	priv->tdastart = addr = 0;
	priv->txbufstart = baddr = sizeof(tda_t) * TXBUFCNT;
	for (z = 0; z < TXBUFCNT; z++) {
		tda.status = 0;
		tda.config = 0;
		tda.length = 0;
		tda.fragcount = 1;
		tda.startlo = baddr;
		tda.starthi = 0;
		tda.fraglength = 0;
		if (z == TXBUFCNT - 1)
			tda.link = priv->tdastart;
		else
			tda.link = addr + sizeof(tda_t);
		tda.link |= 1;
		IBMLANA_TOIO(dev->mem_start + addr, &tda, sizeof(tda_t));
		addr += sizeof(tda_t);
		baddr += PKTSIZE;
	}

	/* calculate how many receive buffers fit into remaining memory */

	priv->rxbufcnt = (dev->mem_end - dev->mem_start - baddr) /
	    (sizeof(rra_t) + sizeof(rda_t) + PKTSIZE);

	/* calculate receive addresses */

	priv->rrastart = raddr = priv->txbufstart + (TXBUFCNT * PKTSIZE);
	priv->rdastart = addr =
	    priv->rrastart + (priv->rxbufcnt * sizeof(rra_t));
	priv->rxbufstart = baddr =
	    priv->rdastart + (priv->rxbufcnt * sizeof(rda_t));
	for (z = 0; z < priv->rxbufcnt; z++) {
		rra.startlo = baddr;
		rra.starthi = 0;
		rra.cntlo = PKTSIZE >> 1;
		rra.cnthi = 0;
		IBMLANA_TOIO(dev->mem_start + raddr, &rra, sizeof(rra_t));

		rda.status = 0;
		rda.length = 0;
		rda.startlo = 0;
		rda.starthi = 0;
		rda.seqno = 0;
		if (z < priv->rxbufcnt - 1)
			rda.link = addr + sizeof(rda_t);
		else
			rda.link = 1;
		rda.inuse = 1;
		IBMLANA_TOIO(dev->mem_start + addr, &rda, sizeof(rda_t));

		baddr += PKTSIZE;
		raddr += sizeof(rra_t);
		addr += sizeof(rda_t);
	}

	/* initialize current pointers */

	priv->nextrxdescr = 0;
	priv->lastrxdescr = priv->rxbufcnt - 1;
	priv->nexttxdescr = 0;
	priv->currtxdescr = 0;
	priv->txusedcnt = 0;
	memset(priv->txused, 0, sizeof(priv->txused));
}

/* set up Rx + Tx descriptors in SONIC */

static int InitSONIC(struct IBMLANA_NETDEV *dev)
{
	ibmlana_priv *priv = (ibmlana_priv *) dev->priv;

	/* set up start & end of resource area */

	outw(0, SONIC_URRA);
	outw(priv->rrastart, dev->base_addr + SONIC_RSA);
	outw(priv->rrastart + (priv->rxbufcnt * sizeof(rra_t)),
	     dev->base_addr + SONIC_REA);
	outw(priv->rrastart, dev->base_addr + SONIC_RRP);
	outw(priv->rrastart, dev->base_addr + SONIC_RWP);

	/* set EOBC so that only one packet goes into one buffer */

	outw((PKTSIZE - 4) >> 1, dev->base_addr + SONIC_EOBC);

	/* let SONIC read the first RRA descriptor */

	outw(CMDREG_RRRA, dev->base_addr + SONIC_CMDREG);
	if (!wait_timeout(dev, SONIC_CMDREG, CMDREG_RRRA, 0, 2)) {
		printk
		    ("%s: SONIC did not respond on RRRA command - giving up.",
		     dev->name);
		return 0;
	}

	/* point SONIC to the first RDA */

	outw(0, dev->base_addr + SONIC_URDA);
	outw(priv->rdastart, dev->base_addr + SONIC_CRDA);

	/* set upper half of TDA address */

	outw(0, dev->base_addr + SONIC_UTDA);

	return 1;
}

/* stop SONIC so we can reinitialize it */

static void StopSONIC(struct IBMLANA_NETDEV *dev)
{
	/* disable interrupts */

	outb(inb(dev->base_addr + BCMREG) & (~BCMREG_IEN),
	     dev->base_addr + BCMREG);
	outb(0, dev->base_addr + SONIC_IMREG);

	/* reset the SONIC */

	outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
	udelay(10);
	outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
}

/* initialize card and SONIC for proper operation */

static void putcam(camentry_t * cams, int *camcnt, char *addr)
{
	camentry_t *pcam = cams + (*camcnt);
	u8 *uaddr = (u8 *) addr;

	pcam->index = *camcnt;
	pcam->addr0 = (((u16) uaddr[1]) << 8) | uaddr[0];
	pcam->addr1 = (((u16) uaddr[3]) << 8) | uaddr[2];
	pcam->addr2 = (((u16) uaddr[5]) << 8) | uaddr[4];
	(*camcnt)++;
}

static void InitBoard(struct IBMLANA_NETDEV *dev)
{
	int camcnt;
	camentry_t cams[16];
	u32 cammask;
	struct dev_mc_list *mcptr;
	u16 rcrval;

	/* reset the SONIC */

	outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
	udelay(10);

	/* clear all spurious interrupts */

	outw(inw(dev->base_addr + SONIC_ISREG),
	     dev->base_addr + SONIC_ISREG);

	/* set up the SONIC's bus interface - constant for this adapter -
	   must be done while the SONIC is in reset */

	outw(DCREG_USR1 | DCREG_USR0 | DCREG_WC1 | DCREG_DW32,
	     dev->base_addr + SONIC_DCREG);
	outw(0, dev->base_addr + SONIC_DCREG2);

	/* remove reset form the SONIC */

	outw(0, dev->base_addr + SONIC_CMDREG);
	udelay(10);

	/* data sheet requires URRA to be programmed before setting up the CAM contents */

	outw(0, dev->base_addr + SONIC_URRA);

	/* program the CAM entry 0 to the device address */

	camcnt = 0;
	putcam(cams, &camcnt, dev->dev_addr);

	/* start putting the multicast addresses into the CAM list.  Stop if
	   it is full. */

	for (mcptr = dev->mc_list; mcptr != NULL; mcptr = mcptr->next) {
		putcam(cams, &camcnt, mcptr->dmi_addr);
		if (camcnt == 16)
			break;
	}

	/* calculate CAM mask */

	cammask = (1 << camcnt) - 1;

	/* feed CDA into SONIC, initialize RCR value (always get broadcasts) */

	IBMLANA_TOIO(dev->mem_start, cams, sizeof(camentry_t) * camcnt);
	IBMLANA_TOIO(dev->mem_start + (sizeof(camentry_t) * camcnt),
		     &cammask, sizeof(cammask));

#ifdef DEBUG
	printk("CAM setup:\n");
	dumpmem(dev, 0, sizeof(camentry_t) * camcnt + sizeof(cammask));
#endif

	outw(0, dev->base_addr + SONIC_CAMPTR);
	outw(camcnt, dev->base_addr + SONIC_CAMCNT);
	outw(CMDREG_LCAM, dev->base_addr + SONIC_CMDREG);
	if (!wait_timeout(dev, SONIC_CMDREG, CMDREG_LCAM, 0, 2)) {
		printk
		    ("%s:SONIC did not respond on LCAM command - giving up.",
		     dev->name);
		return;
	} else {
		/* clear interrupt condition */

		outw(ISREG_LCD, dev->base_addr + SONIC_ISREG);

#ifdef DEBUG
		printk("Loading CAM done, address pointers %04x:%04x\n",
		       inw(dev->base_addr + SONIC_URRA),
		       inw(dev->base_addr + SONIC_CAMPTR));
		{
			int z;

			printk("\n-->CAM: PTR %04x CNT %04x\n",
			       inw(dev->base_addr + SONIC_CAMPTR),
			       inw(dev->base_addr + SONIC_CAMCNT));
			outw(CMDREG_RST, dev->base_addr + SONIC_CMDREG);
			for (z = 0; z < camcnt; z++) {
				outw(z, dev->base_addr + SONIC_CAMEPTR);
				printk("Entry %d: %04x %04x %04x\n", z,
				       inw(dev->base_addr +
					   SONIC_CAMADDR0),
				       inw(dev->base_addr +
					   SONIC_CAMADDR1),
				       inw(dev->base_addr +
					   SONIC_CAMADDR2));
			}
			outw(0, dev->base_addr + SONIC_CMDREG);
		}
#endif
	}

	rcrval = RCREG_BRD | RCREG_LB_NONE;

	/* if still multicast addresses left or ALLMULTI is set, set the multicast
	   enable bit */

	if ((dev->flags & IFF_ALLMULTI) || (mcptr != NULL))
		rcrval |= RCREG_AMC;

	/* promiscous mode ? */

	if (dev->flags & IFF_PROMISC)
		rcrval |= RCREG_PRO;

	/* program receive mode */

	outw(rcrval, dev->base_addr + SONIC_RCREG);
#ifdef DEBUG
	printk("\nRCRVAL: %04x\n", rcrval);
#endif

	/* set up descriptors in shared memory + feed them into SONIC registers */

	InitDscrs(dev);
	if (!InitSONIC(dev))
		return;

	/* reset all pending interrupts */

	outw(0xffff, dev->base_addr + SONIC_ISREG);

	/* enable transmitter + receiver interrupts */

	outw(CMDREG_RXEN, dev->base_addr + SONIC_CMDREG);
	outw(IMREG_PRXEN | IMREG_RBEEN | IMREG_PTXEN | IMREG_TXEREN,
	     dev->base_addr + SONIC_IMREG);

	/* turn on card interrupts */

	outb(inb(dev->base_addr + BCMREG) | BCMREG_IEN,
	     dev->base_addr + BCMREG);

#ifdef DEBUG
	printk("Register dump after initialization:\n");
	dumpregs(dev);
#endif
}

/* start transmission of a descriptor */

static void StartTx(struct IBMLANA_NETDEV *dev, int descr)
{
	ibmlana_priv *priv = (ibmlana_priv *) dev->priv;
	int addr;

	addr = priv->tdastart + (descr * sizeof(tda_t));

	/* put descriptor address into SONIC */

	outw(addr, dev->base_addr + SONIC_CTDA);

	/* trigger transmitter */

	priv->currtxdescr = descr;
	outw(CMDREG_TXP, dev->base_addr + SONIC_CMDREG);
}

/* ------------------------------------------------------------------------
 * interrupt handler(s)
 * ------------------------------------------------------------------------ */

/* receive buffer area exhausted */

static void irqrbe_handler(struct IBMLANA_NETDEV *dev)
{
	ibmlana_priv *priv = (ibmlana_priv *) dev->priv;

	/* point the SONIC back to the RRA start */

	outw(priv->rrastart, dev->base_addr + SONIC_RRP);
	outw(priv->rrastart, dev->base_addr + SONIC_RWP);
}

/* receive interrupt */

static void irqrx_handler(struct IBMLANA_NETDEV *dev)
{
	ibmlana_priv *priv = (ibmlana_priv *) dev->priv;
	rda_t rda;
	u32 rdaaddr, lrdaaddr;

	/* loop until ... */

	while (1) {
		/* read descriptor that was next to be filled by SONIC */

		rdaaddr =
		    priv->rdastart + (priv->nextrxdescr * sizeof(rda_t));
		lrdaaddr =
		    priv->rdastart + (priv->lastrxdescr * sizeof(rda_t));
		IBMLANA_FROMIO(&rda, dev->mem_start + rdaaddr,
			       sizeof(rda_t));

		/* iron out upper word halves of fields we use - SONIC will duplicate 
		   bits 0..15 to 16..31 */

		rda.status &= 0xffff;
		rda.length &= 0xffff;
		rda.startlo &= 0xffff;

		/* stop if the SONIC still owns it, i.e. there is no data for us */

		if (rda.inuse)
			break;

		/* good packet? */

		else if (rda.status & RCREG_PRX) {
			struct sk_buff *skb;

			/* fetch buffer */

			skb = dev_alloc_skb(rda.length + 2);
			if (skb == NULL)
				priv->stat.rx_dropped++;
			else {
				/* copy out data */

				IBMLANA_FROMIO(skb_put(skb, rda.length),
					       dev->mem_start +
					       rda.startlo, rda.length);

				/* set up skb fields */

				skb->dev = dev;
				skb->protocol = eth_type_trans(skb, dev);
				skb->ip_summed = CHECKSUM_NONE;

				/* bookkeeping */

				priv->stat.rx_packets++;
#if (LINUX_VERSION_CODE >= 0x20119)	/* byte counters for kernel >= 2.1.25 */