/* smc-ultra.c: A SMC Ultra ethernet driver for linux. */
/*
	Written 1993,1994,1995 by Donald Becker.

	Copyright 1993 United States Government as represented by the
	Director, National Security Agency.

	This software may be used and distributed according to the terms
	of the GNU Public License, incorporated herein by reference.

	The author may be reached as becker@CESDIS.gsfc.nasa.gov, or C/O
	Center of Excellence in Space Data and Information Sciences
		Code 930.5, Goddard Space Flight Center, Greenbelt MD 20771

	This is a driver for the SMC Ultra and SMC EtherEZ ethercards.

	This driver uses the cards in the 8390-compatible, shared memory mode.
	Most of the run-time complexity is handled by the generic code in
	8390.c.  The code in this file is responsible for

		ultra_probe()	 	Detecting and initializing the card.
		ultra_probe1()	

		ultra_open()		The card-specific details of starting, stopping
		ultra_reset_8390()	and resetting the 8390 NIC core.
		ultra_close()

		ultra_block_input()		Routines for reading and writing blocks of
		ultra_block_output()	packet buffer memory.

	This driver enables the shared memory only when doing the actual data
	transfers to avoid a bug in early version of the card that corrupted
	data transferred by a AHA1542.

	This driver does not support the programmed-I/O data transfer mode of
	the EtherEZ.  That support (if available) is smc-ez.c.  Nor does it
	use the non-8390-compatible "Altego" mode. (No support currently planned.)
*/

static char *version =
	"smc-ultra.c:v1.12 1/18/95 Donald Becker (becker@cesdis.gsfc.nasa.gov)\n";

#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/errno.h>
#include <linux/string.h>
#include <asm/io.h>
#include <asm/system.h>

#include <linux/netdevice.h>
#include "8390.h"
extern struct device *init_etherdev(struct device *dev, int sizeof_private,
									unsigned long *mem_startp);

/* A zero-terminated list of I/O addresses to be probed. */
static unsigned int ultra_portlist[] =
{0x200, 0x220, 0x240, 0x280, 0x300, 0x340, 0x380, 0};

int ultra_probe(struct device *dev);
int ultra_probe1(struct device *dev, int ioaddr);

static int ultra_open(struct device *dev);
static void ultra_reset_8390(struct device *dev);
static int ultra_block_input(struct device *dev, int count,
						  char *buf, int ring_offset);
static void ultra_block_output(struct device *dev, int count,
							const unsigned char *buf, const start_page);
static int ultra_close_card(struct device *dev);


#define START_PG		0x00	/* First page of TX buffer */

#define ULTRA_CMDREG	0		/* Offset to ASIC command register. */
#define	 ULTRA_RESET	0x80	/* Board reset, in ULTRA_CMDREG. */
#define	 ULTRA_MEMENB	0x40	/* Enable the shared memory. */
#define ULTRA_NIC_OFFSET  16	/* NIC register offset from the base_addr. */
#define ULTRA_IO_EXTENT 32

/*	Probe for the Ultra.  This looks like a 8013 with the station
	address PROM at I/O ports <base>+8 to <base>+13, with a checksum
	following.
*/
#ifdef HAVE_DEVLIST
struct netdev_entry ultra_drv =
{"ultra", ultra_probe1, NETCARD_IO_EXTENT, netcard_portlist};
#else

int ultra_probe(struct device *dev)
{
	int i;
	int base_addr = dev ? dev->base_addr : 0;

	if (base_addr > 0x1ff)		/* Check a single specified location. */
		return ultra_probe1(dev, base_addr);
	else if (base_addr != 0)	/* Don't probe at all. */
		return ENXIO;

	for (i = 0; ultra_portlist[i]; i++) {
		int ioaddr = ultra_portlist[i];
		if (check_region(ioaddr, ULTRA_IO_EXTENT))
			continue;
		if (ultra_probe1(dev, ioaddr) == 0)
			return 0;
	}

	return ENODEV;
}
#endif

int ultra_probe1(struct device *dev, int ioaddr)
{
	int i;
	int checksum = 0;
	char *model_name;
	unsigned char eeprom_irq = 0;
	/* Values from various config regs. */
	unsigned char num_pages, irqreg, addr;
	unsigned char idreg = inb(ioaddr + 7);
	unsigned char reg4 = inb(ioaddr + 4) & 0x7f;

	/* Check the ID nibble. */
	if ((idreg & 0xF0) != 0x20 			/* SMC Ultra */
		&& (idreg & 0xF0) != 0x40) 		/* SMC EtherEZ */
		return ENODEV;

	/* Select the station address register set. */
	outb(reg4, ioaddr + 4);

	for (i = 0; i < 8; i++)
		checksum += inb(ioaddr + 8 + i);
	if ((checksum & 0xff) != 0xFF)
		return ENODEV;

	if (dev == NULL)
		dev = init_etherdev(0, sizeof(struct ei_device), 0);

	model_name = (idreg & 0xF0) == 0x20 ? "SMC Ultra" : "SMC EtherEZ";

	printk("%s: %s at %#3x,", dev->name, model_name, ioaddr);

	for (i = 0; i < 6; i++)
		printk(" %2.2X", dev->dev_addr[i] = inb(ioaddr + 8 + i));

	/* Switch from the station address to the alternate register set and
	   read the useful registers there. */
	outb(0x80 | reg4, ioaddr + 4);

	/* Enabled FINE16 mode to avoid BIOS ROM width mismatches @ reboot. */
	outb(0x80 | inb(ioaddr + 0x0c), ioaddr + 0x0c);
	irqreg = inb(ioaddr + 0xd);
	addr = inb(ioaddr + 0xb);

	/* Switch back to the station address register set so that the MS-DOS driver
	   can find the card after a warm boot. */
	outb(reg4, ioaddr + 4);

	if (dev->irq < 2) {
		unsigned char irqmap[] = {0, 9, 3, 5, 7, 10, 11, 15};
		int irq;

		/* The IRQ bits are split. */
		irq = irqmap[((irqreg & 0x40) >> 4) + ((irqreg & 0x0c) >> 2)];

		if (irq == 0) {
			printk(", failed to detect IRQ line.\n");
			return -EAGAIN;
		}
		dev->irq = irq;
		eeprom_irq = 1;
	}


	/* OK, we are certain this is going to work.  Setup the device. */
	request_region(ioaddr, 32, model_name);

	/* The 8390 isn't at the base address, so fake the offset */
	dev->base_addr = ioaddr+ULTRA_NIC_OFFSET;

	{
		int addr_tbl[4] = {0x0C0000, 0x0E0000, 0xFC0000, 0xFE0000};
		short num_pages_tbl[4] = {0x20, 0x40, 0x80, 0xff};

		dev->mem_start = ((addr & 0x0f) << 13) + addr_tbl[(addr >> 6) & 3] ;
		num_pages = num_pages_tbl[(addr >> 4) & 3];
	}

	ethdev_init(dev);

	ei_status.name = model_name;
	ei_status.word16 = 1;
	ei_status.tx_start_page = START_PG;
	ei_status.rx_start_page = START_PG + TX_PAGES;
	ei_status.stop_page = num_pages;

	dev->rmem_start = dev->mem_start + TX_PAGES*256;
	dev->mem_end = dev->rmem_end
		= dev->mem_start + (ei_status.stop_page - START_PG)*256;

	printk(",%s IRQ %d memory %#lx-%#lx.\n", eeprom_irq ? "" : "assigned ",
		   dev->irq, dev->mem_start, dev->mem_end-1);
	if (ei_debug > 0)
		printk(version);

	ei_status.reset_8390 = &ultra_reset_8390;
	ei_status.block_input = &ultra_block_input;
	ei_status.block_output = &ultra_block_output;
	dev->open = &ultra_open;
	dev->stop = &ultra_close_card;
	NS8390_init(dev, 0);

	return 0;
}

static int
ultra_open(struct device *dev)
{
	int ioaddr = dev->base_addr - ULTRA_NIC_OFFSET; /* ASIC addr */

	if (request_irq(dev->irq, ei_interrupt, 0, ei_status.name))
		return -EAGAIN;

	outb(ULTRA_MEMENB, ioaddr);	/* Enable memory, 16 bit mode. */
	outb(0x80, ioaddr + 5);
	outb(0x01, ioaddr + 6);		/* Enable interrupts and memory. */
	return ei_open(dev);
}

static void
ultra_reset_8390(struct device *dev)
{
	int cmd_port = dev->base_addr - ULTRA_NIC_OFFSET; /* ASIC base addr */

	outb(ULTRA_RESET, cmd_port);
	if (ei_debug > 1) printk("resetting Ultra, t=%ld...", jiffies);
	ei_status.txing = 0;

	outb(ULTRA_MEMENB, cmd_port);

	if (ei_debug > 1) printk("reset done\n");
	return;
}

/* Block input and output are easy on shared memory ethercards, the only
   complication is when the ring buffer wraps. */

static int
ultra_block_input(struct device *dev, int count, char *buf, int ring_offset)
{
	void *xfer_start = (void *)(dev->mem_start + ring_offset
								- (START_PG<<8));

	/* Enable shared memory. */
	outb(ULTRA_MEMENB, dev->base_addr - ULTRA_NIC_OFFSET);

	if (xfer_start + count > (void*) dev->rmem_end) {
		/* We must wrap the input move. */
		int semi_count = (void*)dev->rmem_end - xfer_start;
		memcpy(buf, xfer_start, semi_count);
		count -= semi_count;
		memcpy(buf + semi_count, (char *)dev->rmem_start, count);
		outb(0x00, dev->base_addr - ULTRA_NIC_OFFSET); /* Disable memory. */
		return dev->rmem_start + count;
	}
	memcpy(buf, xfer_start, count);

	outb(0x00, dev->base_addr - ULTRA_NIC_OFFSET); /* Disable memory. */
	return ring_offset + count;
}

static void
ultra_block_output(struct device *dev, int count, const unsigned char *buf,
				int start_page)
{
	unsigned char *shmem
		= (unsigned char *)dev->mem_start + ((start_page - START_PG)<<8);

	/* Enable shared memory. */
	outb(ULTRA_MEMENB, dev->base_addr - ULTRA_NIC_OFFSET);

	memcpy(shmem, buf, count);

	outb(0x00, dev->base_addr - ULTRA_NIC_OFFSET); /* Disable memory. */
}

static int
ultra_close_card(struct device *dev)
{
	int ioaddr = dev->base_addr - ULTRA_NIC_OFFSET; /* CMDREG */

	dev->start = 0;
	dev->tbusy = 1;

	if (ei_debug > 1)
		printk("%s: Shutting down ethercard.\n", dev->name);

	outb(0x00, ioaddr + 6);		/* Disable interrupts. */
	free_irq(dev->irq);
	irq2dev_map[dev->irq] = 0;

	NS8390_init(dev, 0);

	/* We should someday disable shared memory and change to 8-bit mode
	   "just in case"... */

	return 0;
}


/*
 * Local variables:
 *  compile-command: "gcc -D__KERNEL__ -Wall -O6 -I/usr/src/linux/net/inet -c smc-ultra.c"
 *  version-control: t
 *  kept-new-versions: 5
 *  c-indent-level: 4
 *  tab-width: 4
 * End:
 */