3c523.c

/*
   net-3-driver for the 3c523 Etherlink/MC card (i82586 Ethernet chip)


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

   Copyright 1995, 1996 by Chris Beauregard (cpbeaure@undergrad.math.uwaterloo.ca)

   This is basically Michael Hipp's ni52 driver, with a new probing
   algorithm and some minor changes to the 82586 CA and reset routines.
   Thanks a lot Michael for a really clean i82586 implementation!  Unless
   otherwise documented in ni52.c, any bugs are mine.

   Contrary to the Ethernet-HOWTO, this isn't based on the 3c507 driver in
   any way.  The ni52 is a lot easier to modify.

   sources:
   ni52.c

   Crynwr packet driver collection was a great reference for my first
   attempt at this sucker.  The 3c507 driver also helped, until I noticed
   that ni52.c was a lot nicer.

   EtherLink/MC: Micro Channel Ethernet Adapter Technical Reference
   Manual, courtesy of 3Com CardFacts, documents the 3c523-specific
   stuff.  Information on CardFacts is found in the Ethernet HOWTO.
   Also see <a href="http://www.3com.com/">

   Microprocessor Communications Support Chips, T.J. Byers, ISBN
   0-444-01224-9, has a section on the i82586.  It tells you just enough
   to know that you really don't want to learn how to program the chip.

   The original device probe code was stolen from ps2esdi.c

   Known Problems:
   Since most of the code was stolen from ni52.c, you'll run across the
   same bugs in the 0.62 version of ni52.c, plus maybe a few because of
   the 3c523 idiosynchacies.  The 3c523 has 16K of RAM though, so there
   shouldn't be the overrun problem that the 8K ni52 has.

   This driver is for a 16K adapter.  It should work fine on the 64K
   adapters, but it will only use one of the 4 banks of RAM.  Modifying
   this for the 64K version would require a lot of heinous bank
   switching, which I'm sure not interested in doing.  If you try to
   implement a bank switching version, you'll basically have to remember
   what bank is enabled and do a switch every time you access a memory
   location that's not current.  You'll also have to remap pointers on
   the driver side, because it only knows about 16K of the memory.
   Anyone desperate or masochistic enough to try?

   It seems to be stable now when multiple transmit buffers are used.  I
   can't see any performance difference, but then I'm working on a 386SX.

   Multicast doesn't work.  It doesn't even pretend to work.  Don't use
   it.  Don't compile your kernel with multicast support.  I don't know
   why.

   Features:
   This driver is useable as a loadable module.  If you try to specify an
   IRQ or a IO address (via insmod 3c523.o irq=xx io=0xyyy), it will
   search the MCA slots until it finds a 3c523 with the specified
   parameters.

   This driver does support multiple ethernet cards when used as a module
   (up to MAX_3C523_CARDS, the default being 4)

   This has been tested with both BNC and TP versions, internal and
   external transceivers.  Haven't tested with the 64K version (that I
   know of).

   History:
   Jan 1st, 1996
   first public release
   Feb 4th, 1996
   update to 1.3.59, incorporated multicast diffs from ni52.c
   Feb 15th, 1996
   added shared irq support
   Apr 1999
   added support for multiple cards when used as a module
   added option to disable multicast as is causes problems
       Ganesh Sittampalam <ganesh.sittampalam@magdalen.oxford.ac.uk>
       Stuart Adamson <stuart.adamson@compsoc.net>
   Nov 2001
   added support for ethtool (jgarzik)

   $Header: /fsys2/home/chrisb/linux-1.3.59-MCA/drivers/net/RCS/3c523.c,v 1.1 1996/02/05 01:53:46 chrisb Exp chrisb $
 */

#define DRV_NAME		"3c523"
#define DRV_VERSION		"17-Nov-2001"

#include <linux/init.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/ioport.h>
#include <linux/skbuff.h>
#include <linux/interrupt.h>
#include <linux/delay.h>
#include <linux/mca-legacy.h>
#include <linux/ethtool.h>
#include <linux/bitops.h>
#include <linux/jiffies.h>

#include <asm/uaccess.h>
#include <asm/processor.h>
#include <asm/io.h>

#include "3c523.h"

/*************************************************************************/
#define DEBUG			/* debug on */
#define SYSBUSVAL 0		/* 1 = 8 Bit, 0 = 16 bit - 3c523 only does 16 bit */
#undef ELMC_MULTICAST		/* Disable multicast support as it is somewhat seriously broken at the moment */

#define make32(ptr16) (p->memtop + (short) (ptr16) )
#define make24(ptr32) ((char *) (ptr32) - p->base)
#define make16(ptr32) ((unsigned short) ((unsigned long) (ptr32) - (unsigned long) p->memtop ))

/*************************************************************************/
/*
   Tables to which we can map values in the configuration registers.
 */
static int irq_table[] __initdata = {
	12, 7, 3, 9
};

static int csr_table[] __initdata = {
	0x300, 0x1300, 0x2300, 0x3300
};

static int shm_table[] __initdata = {
	0x0c0000, 0x0c8000, 0x0d0000, 0x0d8000
};

/******************* how to calculate the buffers *****************************


  * IMPORTANT NOTE: if you configure only one NUM_XMIT_BUFFS, the driver works
  * --------------- in a different (more stable?) mode. Only in this mode it's
  *                 possible to configure the driver with 'NO_NOPCOMMANDS'

sizeof(scp)=12; sizeof(scb)=16; sizeof(iscp)=8;
sizeof(scp)+sizeof(iscp)+sizeof(scb) = 36 = INIT
sizeof(rfd) = 24; sizeof(rbd) = 12;
sizeof(tbd) = 8; sizeof(transmit_cmd) = 16;
sizeof(nop_cmd) = 8;

  * if you don't know the driver, better do not change this values: */

#define RECV_BUFF_SIZE 1524	/* slightly oversized */
#define XMIT_BUFF_SIZE 1524	/* slightly oversized */
#define NUM_XMIT_BUFFS 1	/* config for both, 8K and 16K shmem */
#define NUM_RECV_BUFFS_8  4	/* config for 8K shared mem */
#define NUM_RECV_BUFFS_16 9	/* config for 16K shared mem */

#if (NUM_XMIT_BUFFS == 1)
#define NO_NOPCOMMANDS		/* only possible with NUM_XMIT_BUFFS=1 */
#endif

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

#define DELAY(x) { mdelay(32 * x); }

/* a much shorter delay: */
#define DELAY_16(); { udelay(16) ; }

/* wait for command with timeout: */
#define WAIT_4_SCB_CMD() { int i; \
  for(i=0;i<1024;i++) { \
    if(!p->scb->cmd) break; \
    DELAY_16(); \
    if(i == 1023) { \
      pr_warning("%s:%d: scb_cmd timed out .. resetting i82586\n",\
      	dev->name,__LINE__); \
      elmc_id_reset586(); } } }

static irqreturn_t elmc_interrupt(int irq, void *dev_id);
static int elmc_open(struct net_device *dev);
static int elmc_close(struct net_device *dev);
static netdev_tx_t elmc_send_packet(struct sk_buff *, struct net_device *);
static struct net_device_stats *elmc_get_stats(struct net_device *dev);
static void elmc_timeout(struct net_device *dev);
#ifdef ELMC_MULTICAST
static void set_multicast_list(struct net_device *dev);
#endif
static const struct ethtool_ops netdev_ethtool_ops;

/* helper-functions */
static int init586(struct net_device *dev);
static int check586(struct net_device *dev, unsigned long where, unsigned size);
static void alloc586(struct net_device *dev);
static void startrecv586(struct net_device *dev);
static void *alloc_rfa(struct net_device *dev, void *ptr);
static void elmc_rcv_int(struct net_device *dev);
static void elmc_xmt_int(struct net_device *dev);