/*****************************************************************************
* sdladrv.c	SDLA Support Module.  Main module.
*
*		This module is a library of common hardware-specific functions
*		used by all Sangoma drivers.
*
* Author:	Gene Kozin	<genek@compuserve.com>
*
* Copyright:	(c) 1995-1996 Sangoma Technologies Inc.
*
*		This program is free software; you can redistribute it and/or
*		modify it under the terms of the GNU General Public License
*		as published by the Free Software Foundation; either version
*		2 of the License, or (at your option) any later version.
* ============================================================================
* Dec 20, 1996	Gene Kozin	Version 3.0.0. Complete overhaul.
* Jul 12, 1996	Gene Kozin	Changes for Linux 2.0 compatibility.
* Jun 12, 1996	Gene Kozin 	Added support for S503 card.
* Apr 30, 1996	Gene Kozin	SDLA hardware interrupt is acknowledged before
*				calling protocolspecific ISR.
*				Register I/O ports with Linux kernel.
*				Miscellaneous bug fixes.
* Dec 20, 1995	Gene Kozin	Fixed a bug in interrupt routine.
* Oct 14, 1995	Gene Kozin	Initial version.
*****************************************************************************/

/*****************************************************************************
 * Notes:
 * ------
 * 1. This code is ment to be system-independent (as much as possible).  To
 *    achive this, various macros are used to hide system-specific interfaces.
 *    To compile this code, one of the following constants must be defined:
 *
 *	Platform	Define
 *	--------	------
 *	Linux		_LINUX_
 *	SCO Unix	_SCO_UNIX_
 *
 * 2. Supported adapter types:
 *
 *	S502A
 *	ES502A (S502E)
 *	S503
 *	S507
 *	S508 (S509)
 *
 * 3. S502A Notes:
 *
 *	There is no separate DPM window enable/disable control in S502A.  It
 *	opens immediately after a window number it written to the HMCR
 *	register.  To close the window, HMCR has to be written a value
 *	????1111b (e.g. 0x0F or 0xFF).
 *
 *	S502A DPM window cannot be located at offset E000 (e.g. 0xAE000).
 *
 *	There should be a delay of ??? before reading back S502A status
 *	register.
 *
 * 4. S502E Notes:
 *
 *	S502E has a h/w bug: although default IRQ line state is HIGH, enabling
 *	interrupts by setting bit 1 of the control register (BASE) to '1'
 *	causes it to go LOW! Therefore, disabling interrupts by setting that
 *	bit to '0' causes low-to-high transition on IRQ line (ghosty
 *	interrupt). The same occurs when disabling CPU by resetting bit 0 of
 *	CPU control register (BASE+3) - see the next note.
 *
 *	S502E CPU and DPM control is limited:
 *
 *	o CPU cannot be stopped independently. Resetting bit 0 of the CPUi
 *	  control register (BASE+3) shuts the board down entirely, including
 *	  DPM;
 *
 *	o DPM access cannot be controlled dynamically. Ones CPU is started,
 *	  bit 1 of the control register (BASE) is used to enable/disable IRQ,
 *	  so that access to shared memory cannot be disabled while CPU is
 *	  running.
 ****************************************************************************/

#define	_LINUX_

#if	defined(_LINUX_)	/****** Linux *******************************/

#include <linux/kernel.h>	/* printk(), and other useful stuff */
#include <linux/stddef.h>	/* offsetof(), etc. */
#include <linux/errno.h>	/* return codes */
#include <linux/string.h>	/* inline memset(), etc. */
#include <linux/module.h>	/* support for loadable modules */
#include <linux/sched.h>	/* for jiffies, HZ, etc. */
#include <linux/sdladrv.h>	/* API definitions */
#include <linux/sdlasfm.h>	/* SDLA firmware module definitions */
#include <linux/init.h>
#include <asm/io.h>		/* for inb(), outb(), etc. */
#define _INB(port)		(inb(port))
#define _OUTB(port, byte)	(outb((byte),(port)))
#define	SYSTEM_TICK		jiffies

#elif	defined(_SCO_UNIX_)	/****** SCO Unix ****************************/
#if	!defined(INKERNEL)
#error	This code MUST be compiled in kernel mode!
#endif
#include <sys/sdladrv.h>	/* API definitions */
#include <sys/sdlasfm.h>	/* SDLA firmware module definitions */
#include <sys/inline.h>		/* for inb(), outb(), etc. */
#define _INB(port)		(inb(port))
#define _OUTB(port, byte)	(outb((port),(byte)))
#define	SYSTEM_TICK		lbolt

#else
#error	Unknown system type!
#endif

#define	MOD_VERSION	3
#define	MOD_RELEASE	0

#define	SDLA_IODELAY	100	/* I/O Rd/Wr delay, 10 works for 486DX2-66 */
#define	EXEC_DELAY	20	/* shared memory access delay, mks */
#define	EXEC_TIMEOUT	(HZ*2)	/* command timeout, in ticks */

/* I/O port address range */
#define S502A_IORANGE	3
#define S502E_IORANGE	4
#define S503_IORANGE	3
#define S507_IORANGE	4
#define S508_IORANGE	4

/* Maximum amount of memory */
#define S502_MAXMEM	0x10000L
#define S503_MAXMEM	0x10000L
#define S507_MAXMEM	0x40000L
#define S508_MAXMEM	0x40000L

/* Minimum amount of memory */
#define S502_MINMEM	0x8000L
#define S503_MINMEM	0x8000L
#define S507_MINMEM	0x20000L
#define S508_MINMEM	0x20000L

/****** Function Prototypes *************************************************/

/* Module entry points. These are called by the OS and must be public. */
int init_module (void);
void cleanup_module (void);

/* Hardware-specific functions */
static int sdla_detect	(sdlahw_t* hw);
static int sdla_autodpm	(sdlahw_t* hw);
static int sdla_setdpm	(sdlahw_t* hw);
static int sdla_load	(sdlahw_t* hw, sfm_t* sfm, unsigned len);
static int sdla_init	(sdlahw_t* hw);
static unsigned long sdla_memtest (sdlahw_t* hw);
static int sdla_bootcfg	(sdlahw_t* hw, sfm_info_t* sfminfo);
static unsigned char make_config_byte (sdlahw_t* hw);
static int sdla_start	(sdlahw_t* hw, unsigned addr);

static int init_s502a	(sdlahw_t* hw);
static int init_s502e	(sdlahw_t* hw);
static int init_s503	(sdlahw_t* hw);
static int init_s507	(sdlahw_t* hw);
static int init_s508	(sdlahw_t* hw);

static int detect_s502a	(int port);
static int detect_s502e	(int port);
static int detect_s503	(int port);
static int detect_s507	(int port);
static int detect_s508	(int port);

/* Miscellaneous functions */
static int calibrate_delay (int mks);
static int get_option_index (unsigned* optlist, unsigned optval);
static unsigned check_memregion (void* ptr, unsigned len);
static unsigned	test_memregion (void* ptr, unsigned len);
static unsigned short checksum (unsigned char* buf, unsigned len);

/****** Global Data **********************************************************
 * Note: All data must be explicitly initialized!!!
 */

/* private data */
static char modname[]	= "sdladrv";
static char fullname[]	= "SDLA Support Module";
static char copyright[]	= "(c) 1995-1996 Sangoma Technologies Inc.";
static unsigned	exec_idle;

/* Hardware configuration options.
 * These are arrays of configuration options used by verification routines.
 * The first element of each array is its size (i.e. number of options).
 */
static unsigned	s502_port_options[] =
	{ 4, 0x250, 0x300, 0x350, 0x360 }
;
static unsigned	s503_port_options[] =
	{ 8, 0x250, 0x254, 0x300, 0x304, 0x350, 0x354, 0x360, 0x364 }
;
static unsigned	s508_port_options[] =
	{ 8, 0x250, 0x270, 0x280, 0x300, 0x350, 0x360, 0x380, 0x390 }
;

static unsigned s502a_irq_options[] = { 0 };
static unsigned s502e_irq_options[] = { 4, 2, 3, 5, 7 };
static unsigned s503_irq_options[]  = { 5, 2, 3, 4, 5, 7 };
static unsigned s508_irq_options[]  = { 8, 3, 4, 5, 7, 10, 11, 12, 15 };

static unsigned s502a_dpmbase_options[] =
{
	28,
	0xA0000, 0xA2000, 0xA4000, 0xA6000, 0xA8000, 0xAA000, 0xAC000,
	0xC0000, 0xC2000, 0xC4000, 0xC6000, 0xC8000, 0xCA000, 0xCC000,
	0xD0000, 0xD2000, 0xD4000, 0xD6000, 0xD8000, 0xDA000, 0xDC000,
	0xE0000, 0xE2000, 0xE4000, 0xE6000, 0xE8000, 0xEA000, 0xEC000,
};
static unsigned s507_dpmbase_options[] =
{
	32,
	0xA0000, 0xA2000, 0xA4000, 0xA6000, 0xA8000, 0xAA000, 0xAC000, 0xAE000,
	0xB0000, 0xB2000, 0xB4000, 0xB6000, 0xB8000, 0xBA000, 0xBC000, 0xBE000,
	0xC0000, 0xC2000, 0xC4000, 0xC6000, 0xC8000, 0xCA000, 0xCC000, 0xCE000,
	0xE0000, 0xE2000, 0xE4000, 0xE6000, 0xE8000, 0xEA000, 0xEC000, 0xEE000,
};
static unsigned s508_dpmbase_options[] =	/* incl. S502E and S503 */
{
	32,
	0xA0000, 0xA2000, 0xA4000, 0xA6000, 0xA8000, 0xAA000, 0xAC000, 0xAE000,
	0xC0000, 0xC2000, 0xC4000, 0xC6000, 0xC8000, 0xCA000, 0xCC000, 0xCE000,
	0xD0000, 0xD2000, 0xD4000, 0xD6000, 0xD8000, 0xDA000, 0xDC000, 0xDE000,
	0xE0000, 0xE2000, 0xE4000, 0xE6000, 0xE8000, 0xEA000, 0xEC000, 0xEE000,
};

/*
static unsigned	s502_dpmsize_options[] = { 2, 0x2000, 0x10000 };
static unsigned	s507_dpmsize_options[] = { 2, 0x2000, 0x4000 };
static unsigned	s508_dpmsize_options[] = { 1, 0x2000 };
*/

static unsigned	s502a_pclk_options[] = { 2, 3600, 7200 };
static unsigned	s502e_pclk_options[] = { 5, 3600, 5000, 7200, 8000, 10000 };
static unsigned	s503_pclk_options[]  = { 3, 7200, 8000, 10000 };
static unsigned	s507_pclk_options[]  = { 1, 12288 };
static unsigned	s508_pclk_options[]  = { 1, 16000 };

/* Host memory control register masks */
static unsigned char s502a_hmcr[] =
{
	0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C,	/* A0000 - AC000 */
	0x20, 0x22, 0x24, 0x26, 0x28, 0x2A, 0x2C,	/* C0000 - CC000 */
	0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C,	/* D0000 - DC000 */
	0x30, 0x32, 0x34, 0x36, 0x38, 0x3A, 0x3C,	/* E0000 - EC000 */
};
static unsigned char s502e_hmcr[] =
{
	0x10, 0x12, 0x14, 0x16, 0x18, 0x1A, 0x1C, 0x1E,	/* A0000 - AE000 */
	0x20, 0x22, 0x24, 0x26, 0x28, 0x2A, 0x2C, 0x2E,	/* C0000 - CE000 */
	0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,	/* D0000 - DE000 */
	0x30, 0x32, 0x34, 0x36, 0x38, 0x3A, 0x3C, 0x3E,	/* E0000 - EE000 */
};
static unsigned char s507_hmcr[] =
{
	0x00, 0x02, 0x04, 0x06, 0x08, 0x0A, 0x0C, 0x0E,	/* A0000 - AE000 */
	0x40, 0x42, 0x44, 0x46, 0x48, 0x4A, 0x4C, 0x4E,	/* B0000 - BE000 */
	0x80, 0x82, 0x84, 0x86, 0x88, 0x8A, 0x8C, 0x8E,	/* C0000 - CE000 */
	0xC0, 0xC2, 0xC4, 0xC6, 0xC8, 0xCA, 0xCC, 0xCE,	/* E0000 - EE000 */
};
static unsigned char s508_hmcr[] =
{
	0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,	/* A0000 - AE000 */
	0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,	/* C0000 - CE000 */
	0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,	/* D0000 - DE000 */
	0x18, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F,	/* E0000 - EE000 */
};

static unsigned char s507_irqmask[] =
{
	0x00, 0x20, 0x40, 0x60, 0x80, 0xA0, 0xC0, 0xE0
};

/******* Kernel Loadable Module Entry Points ********************************/

/*============================================================================
 * Module 'insert' entry point.
 * o print announcement
 * o initialize static data
 * o calibrate SDLA shared memory access delay.
 *
 * Return:	0	Ok
 *		< 0	error.
 * Context:	process
 */

#ifdef MODULE
int init_module (void)
#else
__initfunc(int wanpipe_init(void))
#endif
{
	printk(KERN_INFO "%s v%u.%u %s\n",
		fullname, MOD_VERSION, MOD_RELEASE, copyright);
	exec_idle = calibrate_delay(EXEC_DELAY);
#ifdef WANDEBUG	
	printk(KERN_DEBUG "%s: exec_idle = %d\n", modname, exec_idle);
#endif	
	return 0;
}

#ifdef MODULE
/*============================================================================
 * Module 'remove' entry point.
 * o release all remaining system resources
 */
void cleanup_module (void)
{
}
#endif

/******* Kernel APIs ********************************************************/

/*============================================================================
 * Set up adapter.
 * o detect adapter type
 * o verify hardware configuration options
 * o check for hardware conflicts
 * o set up adapter shared memory
 * o test adapter memory
 * o load firmware
 * Return:	0	ok.
 *		< 0	error
 */
 
EXPORT_SYMBOL(sdla_setup);

int sdla_setup (sdlahw_t* hw, void* sfm, unsigned len)
{
	unsigned* irq_opt	= NULL;	/* IRQ options */
	unsigned* dpmbase_opt	= NULL;	/* DPM window base options */
	unsigned* pclk_opt	= NULL;	/* CPU clock rate options */
	int err;

	if (sdla_detect(hw))
	{
		printk(KERN_ERR "%s: adapter S%04u not found at port 0x%X!\n",
			modname, hw->type, hw->port)
		;
		return -EINVAL;
	}
	printk(KERN_INFO "%s: found S%04u card at port 0x%X.\n",
		modname, hw->type, hw->port)
	;

	hw->dpmsize = SDLA_WINDOWSIZE;
	switch (hw->type)
	{
	case SDLA_S502A:
		hw->io_range	= S502A_IORANGE;
		irq_opt		= s502a_irq_options;
		dpmbase_opt	= s502a_dpmbase_options;
		pclk_opt	= s502a_pclk_options;
		break;

	case SDLA_S502E:
		hw->io_range	= S502E_IORANGE;
		irq_opt		= s502e_irq_options;
		dpmbase_opt	= s508_dpmbase_options;
		pclk_opt	= s502e_pclk_options;
		break;

	case SDLA_S503:
		hw->io_range	= S503_IORANGE;
		irq_opt		= s503_irq_options;
		dpmbase_opt	= s508_dpmbase_options;
		pclk_opt	= s503_pclk_options;
		break;

	case SDLA_S507:
		hw->io_range	= S507_IORANGE;
		irq_opt		= s508_irq_options;
		dpmbase_opt	= s507_dpmbase_options;
		pclk_opt	= s507_pclk_options;
		break;

	case SDLA_S508:
		hw->io_range	= S508_IORANGE;
		irq_opt		= s508_irq_options;
		dpmbase_opt	= s508_dpmbase_options;
		pclk_opt	= s508_pclk_options;
		break;
	}

	/* Verify IRQ configuration options */
	if (!get_option_index(irq_opt, hw->irq))
	{
		printk(KERN_ERR "%s: IRQ %d is illegal!\n",
			modname, hw->irq)
		;
		return -EINVAL;
	} 

	/* Verify CPU clock rate configuration options */
	if (hw->pclk == 0)
		hw->pclk = pclk_opt[1]	/* use default */
	;
	else if (!get_option_index(pclk_opt, hw->pclk))
	{
		printk(KERN_ERR "%s: CPU clock %u is illegal!\n",
			modname, hw->pclk)
		;
		return -EINVAL;
	} 
	printk(KERN_INFO "%s: assuming CPU clock rate of %u kHz.\n",
		modname, hw->pclk)
	;

	/* Setup adapter dual-port memory window and test memory */
	if (hw->dpmbase == 0)
	{
		err = sdla_autodpm(hw);
		if (err)
		{
			printk(KERN_ERR
				"%s: can't find available memory region!\n",
				modname)
			;
 			return err;
		}
	}
	else if (!get_option_index(dpmbase_opt, hw->dpmbase))
	{
		printk(KERN_ERR "%s: memory address 0x%lX is illegal!\n",
			modname, hw->dpmbase)
		;
		return -EINVAL;
	} 
	else if (sdla_setdpm(hw))
	{
		printk(KERN_ERR
			"%s: 8K memory region at 0x%lX is not available!\n",
			modname, hw->dpmbase)
		;
		return -EINVAL;
	} 
	printk(KERN_INFO "%s: dual-port memory window is set at 0x%lX.\n",
		modname, hw->dpmbase)
	;
	printk(KERN_INFO "%s: found %luK bytes of on-board memory.\n",
		modname, hw->memory / 1024)
	;

	/* Load firmware. If loader fails then shut down adapter */
	err = sdla_load(hw, sfm, len);
	if (err) sdla_down(hw);		/* shutdown adapter */
	return err;
} 

/*============================================================================
 * Shut down SDLA: disable shared memory access and interrupts, stop CPU, etc.
 */

EXPORT_SYMBOL(sdla_down);

int sdla_down (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int i;

	if (!port) return -EFAULT;

	switch (hw->type)
	{
	case SDLA_S502A:
		_OUTB(port, 0x08);		/* halt CPU */
		_OUTB(port, 0x08);
		_OUTB(port, 0x08);
		hw->regs[0] = 0x08;
		_OUTB(port + 1, 0xFF);		/* close memory window */
		hw->regs[1] = 0xFF;
		break;

	case SDLA_S502E:
		_OUTB(port + 3, 0);		/* stop CPU */
		_OUTB(port, 0);			/* reset board */
		for (i = 0; i < S502E_IORANGE; ++i)
			hw->regs[i] = 0
		;
		break;

	case SDLA_S503:
	case SDLA_S507:
	case SDLA_S508:
		_OUTB(port, 0);			/* reset board logic */
		hw->regs[0] = 0;
		break;

	default:
		return -EINVAL;
	}
	return 0;
}

/*============================================================================
 * Map shared memory window into SDLA adress space.
 */

EXPORT_SYMBOL(sdla_mapmem);

int sdla_mapmem (sdlahw_t* hw, unsigned long addr)
{
	unsigned port = hw->port;
	register int tmp;

	switch (hw->type)
	{
	case SDLA_S502A:
	case SDLA_S502E:
		if (addr < S502_MAXMEM)	/* verify parameter */
		{
			tmp = addr >> 13;	/* convert to register mask */
			_OUTB(port + 2, tmp);
			hw->regs[2] = tmp;
		}
		else return -EINVAL;
		break;

	case SDLA_S503:
		if (addr < S503_MAXMEM)	/* verify parameter */
		{
			tmp = (hw->regs[0] & 0x8F) | ((addr >> 9) & 0x70);
			_OUTB(port, tmp);
			hw->regs[0] = tmp;
		}
		else return -EINVAL;
		break;

	case SDLA_S507:
		if (addr < S507_MAXMEM)
		{
			if (!(_INB(port) & 0x02))
				return -EIO
			;
			tmp = addr >> 13;	/* convert to register mask */
			_OUTB(port + 2, tmp);
			hw->regs[2] = tmp;
		}
		else return -EINVAL;
		break;

	case SDLA_S508:
		if (addr < S508_MAXMEM)
		{
			tmp = addr >> 13;	/* convert to register mask */
			_OUTB(port + 2, tmp);
			hw->regs[2] = tmp;
		}
		else return -EINVAL;
		break;

	default:
		return -EINVAL;
	}
	hw->vector = addr & 0xFFFFE000L;
	return 0;
}

/*============================================================================
 * Enable interrupt generation.
 */
 
EXPORT_SYMBOL(sdla_inten);

int sdla_inten (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp, i;

	switch (hw->type)
	{
	case SDLA_S502E:
		/* Note thar interrupt control operations on S502E are allowed
		 * only if CPU is enabled (bit 0 of status register is set).
		 */
		if (_INB(port) & 0x01)
		{
			_OUTB(port, 0x02);	/* bit1 = 1, bit2 = 0 */
			_OUTB(port, 0x06);	/* bit1 = 1, bit2 = 1 */
			hw->regs[0] = 0x06;
		}
		else return -EIO;
		break;

	case SDLA_S503:
		tmp = hw->regs[0] | 0x04;
		_OUTB(port, tmp);
		hw->regs[0] = tmp;		/* update mirror */
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
		if (!(_INB(port) & 0x02))		/* verify */
			return -EIO
		;
		break;

	case SDLA_S508:
		tmp = hw->regs[0] | 0x10;
		_OUTB(port, tmp);
		hw->regs[0] = tmp;		/* update mirror */
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
		if (!(_INB(port + 1) & 0x10))		/* verify */
			return -EIO
		;
		break;

	case SDLA_S502A:
	case SDLA_S507:
		break;

	default:
		return -EINVAL;

	}
	return 0;
}

/*============================================================================
 * Disable interrupt generation.
 */

EXPORT_SYMBOL(sdla_intde);

int sdla_intde (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp, i;

	switch (hw->type)
	{
	case SDLA_S502E:
		/* Notes:
		 *  1) interrupt control operations are allowed only if CPU is
		 *     enabled (bit 0 of status register is set).
		 *  2) disabling interrupts using bit 1 of control register
		 *     causes IRQ line go high, therefore we are going to use
		 *     0x04 instead: lower it to inhibit interrupts to PC.
		 */
		if (_INB(port) & 0x01)
		{
			_OUTB(port, hw->regs[0] & ~0x04);
			hw->regs[0] &= ~0x04;
		}
		else return -EIO;
		break;

	case SDLA_S503:
		tmp = hw->regs[0] & ~0x04;
		_OUTB(port, tmp);
		hw->regs[0] = tmp;			/* update mirror */
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
		if (_INB(port) & 0x02)			/* verify */
			return -EIO
		;
		break;

	case SDLA_S508:
		tmp = hw->regs[0] & ~0x10;
		_OUTB(port, tmp);
		hw->regs[0] = tmp;			/* update mirror */
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
		if (_INB(port) & 0x10)			/* verify */
			return -EIO
		;
		break;

	case SDLA_S502A:
	case SDLA_S507:
		break;

	default:
		return -EINVAL;
	}
	return 0;
}

/*============================================================================
 * Acknowledge SDLA hardware interrupt.
 */

EXPORT_SYMBOL(sdla_intack);

int sdla_intack (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp;

	switch (hw->type)
	{
	case SDLA_S502E:
		/* To acknoledge hardware interrupt we have to toggle bit 3 of
		 * control register: \_/
		 * Note that interrupt control operations on S502E are allowed
		 * only if CPU is enabled (bit 1 of status register is set).
		 */
		if (_INB(port) & 0x01)
		{
			tmp = hw->regs[0] & ~0x04;
			_OUTB(port, tmp);
			tmp |= 0x04;
			_OUTB(port, tmp);
			hw->regs[0] = tmp;
		}
		else return -EIO;
		break;

	case SDLA_S503:
		if (_INB(port) & 0x04)
		{
			tmp = hw->regs[0] & ~0x08;
			_OUTB(port, tmp);
			tmp |= 0x08;
			_OUTB(port, tmp);
			hw->regs[0] = tmp;
		}
		break;

	case SDLA_S502A:
	case SDLA_S507:
	case SDLA_S508:
	break;

	default:
		return -EINVAL;
	}
	return 0;
}

/*============================================================================
 * Generate an interrupt to adapter's CPU.
 */

EXPORT_SYMBOL(sdla_intr);

int sdla_intr (sdlahw_t* hw)
{
	unsigned port = hw->port;

	switch (hw->type)
	{
	case SDLA_S502A:
		if (!(_INB(port) & 0x40))
		{
			_OUTB(port, 0x10);		/* issue NMI to CPU */
			hw->regs[0] = 0x10;
		}
		else return -EIO;
		break;

	case SDLA_S507:
		if ((_INB(port) & 0x06) == 0x06)
		{
			_OUTB(port + 3, 0);
		}
		else return -EIO;
		break;

	case SDLA_S508:
		if (_INB(port + 1) & 0x02)
		{
			_OUTB(port, 0x08);
		}
		else return -EIO;
		break;

	case SDLA_S502E:
	case SDLA_S503:
	default:
		return -EINVAL;
	}
	return 0;
}

/*============================================================================
 * Execute Adapter Command.
 * o Set exec flag.
 * o Busy-wait until flag is reset.
 * o Return number of loops made, or 0 if command timed out.
 */

EXPORT_SYMBOL(sdla_exec);

int sdla_exec (void* opflag)
{
	volatile unsigned char* flag = opflag;
	unsigned long tstop;
	int nloops;

	if (*flag) return 0;	/* ???? */

	*flag = 1;
	tstop = SYSTEM_TICK + EXEC_TIMEOUT;
	for (nloops = 1; *flag; ++nloops)
	{
		unsigned delay = exec_idle;
		while (--delay);			/* delay */
		if (SYSTEM_TICK > tstop) return 0;	/* time is up! */
	}
	return nloops;
}

/*============================================================================
 * Read absolute adapter memory.
 * Transfer data from adapter's memory to data buffer.
 *
 * Note:
 * Care should be taken when crossing dual-port memory window boundary.
 * This function is not atomic, so caller must disable interrupt if
 * interrupt routines are accessing adapter shared memory.
 */
 
EXPORT_SYMBOL(sdla_peek);

int sdla_peek (sdlahw_t* hw, unsigned long addr, void* buf, unsigned len)
{
	unsigned long oldvec = hw->vector;
	unsigned winsize = hw->dpmsize;
	unsigned curpos, curlen;	/* current offset and block size */
	unsigned long curvec;		/* current DPM window vector */
	int err = 0;

	if (addr + len > hw->memory)	/* verify arguments */
		return -EINVAL
	;
	while (len && !err)
	{
		curpos = addr % winsize;	/* current window offset */
		curvec = addr - curpos;		/* current window vector */
		curlen = (len > (winsize - curpos)) ? (winsize - curpos) : len;

		/* Relocate window and copy block of data */
		err = sdla_mapmem(hw, curvec);
		memcpy((void*)buf, (void*)(hw->dpmbase + curpos), curlen);
		addr       += curlen;
		(char*)buf += curlen;
		len        -= curlen;
	}

	/* Restore DPM window position */
	sdla_mapmem(hw, oldvec);
	return err;
}

/*============================================================================
 * Write Absolute Adapter Memory.
 * Transfer data from data buffer to adapter's memory.
 *
 * Note:
 * Care should be taken when crossing dual-port memory window boundary.
 * This function is not atomic, so caller must disable interrupt if
 * interrupt routines are accessing adapter shared memory.
 */
 
EXPORT_SYMBOL(sdla_poke);
 
int sdla_poke (sdlahw_t* hw, unsigned long addr, void* buf, unsigned len)
{
	unsigned long oldvec = hw->vector;
	unsigned winsize = hw->dpmsize;
	unsigned curpos, curlen;	/* current offset and block size */
	unsigned long curvec;		/* current DPM window vector */
	int err = 0;

	if (addr + len > hw->memory)	/* verify arguments */
		return -EINVAL
	;
	while (len && !err)
	{
		curpos = addr % winsize;	/* current window offset */
		curvec = addr - curpos;		/* current window vector */
		curlen = (len > (winsize - curpos)) ? (winsize - curpos) : len;

		/* Relocate window and copy block of data */
		sdla_mapmem(hw, curvec);
		memcpy((void*)(hw->dpmbase + curpos), (void*)buf, curlen);
		addr       += curlen;
		(char*)buf += curlen;
		len        -= curlen;
	}

	/* Restore DPM window position */
	sdla_mapmem(hw, oldvec);
	return err;
}

#ifdef	DONT_COMPIPLE_THIS
#endif	/* DONT_COMPIPLE_THIS */

/****** Hardware-Specific Functions *****************************************/

/*============================================================================
 * Detect adapter type.
 * o if adapter type is specified then call detection routine for that adapter
 *   type.  Otherwise call detection routines for every adapter types until
 *   adapter is detected.
 *
 * Notes:
 * 1) Detection tests are destructive! Adapter will be left in shutdown state
 *    after the test.
 */
static int sdla_detect (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int err = 0;

	if (!port)
		return -EFAULT
	;
	switch (hw->type)
	{
	case SDLA_S502A:
		if (!detect_s502a(port)) err = -ENODEV;
		break;

	case SDLA_S502E:
		if (!detect_s502e(port)) err = -ENODEV;
		break;

	case SDLA_S503:
		if (!detect_s503(port)) err = -ENODEV;
		break;

	case SDLA_S507:
		if (!detect_s507(port)) err = -ENODEV;
		break;

	case SDLA_S508:
		if (!detect_s508(port)) err = -ENODEV;
		break;

	default:
		if (detect_s502a(port))
			hw->type = SDLA_S502A
		;
		else if (detect_s502e(port))
			hw->type = SDLA_S502E
		;
		else if (detect_s503(port))
			hw->type = SDLA_S503
		;
		else if (detect_s507(port))
			hw->type = SDLA_S507
		;
		else if (detect_s508(port))
			hw->type = SDLA_S508
		;
		else err = -ENODEV;
	}
	return err;
}

/*============================================================================
 * Autoselect memory region. 
 * o try all available DMP address options from the top down until success.
 */
static int sdla_autodpm (sdlahw_t* hw)
{
	int i, err = -EINVAL;
	unsigned* opt;

	switch (hw->type)
	{
	case SDLA_S502A:
		opt = s502a_dpmbase_options;
		break;

	case SDLA_S502E:
	case SDLA_S503:
	case SDLA_S508:
		opt = s508_dpmbase_options;
		break;

	case SDLA_S507:
		opt = s507_dpmbase_options;
		break;

	default:
		return -EINVAL;
	}

	for (i = opt[0]; i && err; --i)
	{
		hw->dpmbase = opt[i];
		err = sdla_setdpm(hw);
	}
	return err;
}

/*============================================================================
 * Set up adapter dual-port memory window. 
 * o shut down adapter
 * o make sure that no physical memory exists in this region, i.e entire
 *   region reads 0xFF and is not writable when adapter is shut down.
 * o initialize adapter hardware
 * o make sure that region is usable with SDLA card, i.e. we can write to it
 *   when adapter is configured.
 */
static int sdla_setdpm (sdlahw_t* hw)
{
	int err;

	/* Shut down card and verify memory region */
	sdla_down(hw);
	if (check_memregion((void*)hw->dpmbase, hw->dpmsize))
		return -EINVAL
	;

	/* Initialize adapter and test on-board memory segment by segment.
	 * If memory size appears to be less than shared memory window size,
	 * assume that memory region is unusable.
	 */
	err = sdla_init(hw);
	if (err) return err;

	if (sdla_memtest(hw) < hw->dpmsize)	/* less than window size */
	{
		sdla_down(hw);
		return -EIO;
	}
	sdla_mapmem(hw, 0L);	/* set window vector at bottom */
	return 0;
}

/*============================================================================
 * Load adapter from the memory image of the SDLA firmware module. 
 * o verify firmware integrity and compatibility
 * o start adapter up
 */
static int sdla_load (sdlahw_t* hw, sfm_t* sfm, unsigned len)
{
	int i;

	/* Verify firmware signature */
	if (strcmp(sfm->signature, SFM_SIGNATURE))
	{
		printk(KERN_ERR "%s: not SDLA firmware!\n",
			modname)
		;
		return -EINVAL;
	}

	/* Verify firmware module format version */
	if (sfm->version != SFM_VERSION)
	{
		printk(KERN_ERR
			"%s: firmware format %u rejected! Expecting %u.\n",
			modname, sfm->version, SFM_VERSION)
		;
		return -EINVAL;
	}

	/* Verify firmware module length and checksum */
	if ((len - offsetof(sfm_t, image) != sfm->info.codesize) ||
		(checksum((void*)&sfm->info,
		sizeof(sfm_info_t) + sfm->info.codesize) != sfm->checksum))
	{
		printk(KERN_ERR "%s: firmware corrupted!\n", modname);
		return -EINVAL;
	}

	/* Announce */
	printk(KERN_INFO "%s: loading %s (ID=%u)...\n", modname,
		(sfm->descr[0] != '\0') ? sfm->descr : "unknown firmware",
		sfm->info.codeid)
	;

	/* Scan through the list of compatible adapters and make sure our
	 * adapter type is listed.
	 */
	for (i = 0;
	     (i < SFM_MAX_SDLA) && (sfm->info.adapter[i] != hw->type);
	     ++i)
	;
	if (i == SFM_MAX_SDLA)
	{
		printk(KERN_ERR "%s: firmware is not compatible with S%u!\n",
			modname, hw->type)
		;
		return -EINVAL;
	}

	/* Make sure there is enough on-board memory */
	if (hw->memory < sfm->info.memsize)
	{
		printk(KERN_ERR
			"%s: firmware needs %lu bytes of on-board memory!\n",
			modname, sfm->info.memsize)
		;
		return -EINVAL;
	}

	/* Move code onto adapter */
	if (sdla_poke(hw, sfm->info.codeoffs, sfm->image, sfm->info.codesize))
	{
		printk(KERN_ERR "%s: failed to load code segment!\n",
			modname)
		;
		return -EIO;
	}

	/* Prepare boot-time configuration data and kick-off CPU */
	sdla_bootcfg(hw, &sfm->info);
	if (sdla_start(hw, sfm->info.startoffs))
	{
		printk(KERN_ERR "%s: Damn... Adapter won't start!\n",
			modname)
		;
		return -EIO;
	}

	/* position DPM window over the mailbox and enable interrupts */
        if (sdla_mapmem(hw, sfm->info.winoffs) || sdla_inten(hw))
	{
		printk(KERN_ERR "%s: adapter hardware failure!\n",
			modname)
		;
		return -EIO;
	}
	hw->fwid = sfm->info.codeid;		/* set firmware ID */
	return 0;
}

/*============================================================================
 * Initialize SDLA hardware: setup memory window, IRQ, etc.
 */
static int sdla_init (sdlahw_t* hw)
{
	int i;

	for (i = 0; i < SDLA_MAXIORANGE; ++i)
		hw->regs[i] = 0
	;
	switch (hw->type)
	{
	case SDLA_S502A: return init_s502a(hw);
	case SDLA_S502E: return init_s502e(hw);
	case SDLA_S503:  return init_s503(hw);
	case SDLA_S507:  return init_s507(hw);
	case SDLA_S508:  return init_s508(hw);
	}
	return -EINVAL;
}

/*============================================================================
 * Test adapter on-board memory.
 * o slide DPM window from the bottom up and test adapter memory segment by
 *   segment.
 * Return adapter memory size.
 */
static unsigned long sdla_memtest (sdlahw_t* hw)
{
	unsigned long memsize;
	unsigned winsize;

	for (memsize = 0, winsize = hw->dpmsize;
	     !sdla_mapmem(hw, memsize) &&
		(test_memregion((void*)hw->dpmbase, winsize) == winsize)
	     ;
	     memsize += winsize)
	;
	hw->memory = memsize;
	return memsize;
}

/*============================================================================
 * Prepare boot-time firmware configuration data.
 * o position DPM window
 * o initialize configuration data area
 */
static int sdla_bootcfg (sdlahw_t* hw, sfm_info_t* sfminfo)
{
	unsigned char* data;

	if (!sfminfo->datasize) return 0;	/* nothing to do */

	if (sdla_mapmem(hw, sfminfo->dataoffs) != 0)
		return -EIO
	;
	data = (void*)(hw->dpmbase + (sfminfo->dataoffs - hw->vector));
	memset(data, 0, sfminfo->datasize);

	data[0x00] = make_config_byte(hw);
	switch (sfminfo->codeid)
	{
	case SFID_X25_502:
	case SFID_X25_508:
		data[0x01] = 3;			/* T1 timer */
		data[0x03] = 10;		/* N2 */
		data[0x06] = 7;			/* HDLC window size */
		data[0x0B] = 1;			/* DTE */
		data[0x0C] = 2;			/* X.25 packet window size */
		*(short*)&data[0x0D] = 128;	/* default X.25 data size */
		*(short*)&data[0x0F] = 128;	/* maximum X.25 data size */
		break;
	}
	return 0;
}

/*============================================================================
 * Prepare configuration byte identifying adapter type and CPU clock rate.
 */
static unsigned char make_config_byte (sdlahw_t* hw)
{
	unsigned char byte = 0;

	switch (hw->pclk)
	{
		case 5000:  byte = 0x01; break;
		case 7200:  byte = 0x02; break;
		case 8000:  byte = 0x03; break;
		case 10000: byte = 0x04; break;
		case 16000: byte = 0x05; break;
	}
	switch (hw->type)
	{
		case SDLA_S502E: byte |= 0x80; break;
		case SDLA_S503:  byte |= 0x40; break;
	}
	return byte;
}

/*============================================================================
 * Start adapter's CPU.
 * o calculate a pointer to adapter's cold boot entry point
 * o position DPM window
 * o place boot instruction (jp addr) at cold boot entry point
 * o start CPU
 */
static int sdla_start (sdlahw_t* hw, unsigned addr)
{
	unsigned port = hw->port;
	unsigned char* bootp;
	int err, tmp, i;

	if (!port) return -EFAULT;

	switch (hw->type)
	{
	case SDLA_S502A:
		bootp = (void*)(hw->dpmbase + 0x66);
		break;

	case SDLA_S502E:
	case SDLA_S503:
	case SDLA_S507:
	case SDLA_S508:
		bootp = (void*)hw->dpmbase;
		break;

	default:
		return -EINVAL;
	}

	err = sdla_mapmem(hw, 0);
	if (err) return err;

	*bootp = 0xC3;	 /* Z80: 'jp' opcode */
	bootp++;
	*((unsigned short*)(bootp)) = addr;

	switch (hw->type)
	{
	case SDLA_S502A:
		_OUTB(port, 0x10);		/* issue NMI to CPU */
		hw->regs[0] = 0x10;
		break;

	case SDLA_S502E:
		_OUTB(port + 3, 0x01);		/* start CPU */
		hw->regs[3] = 0x01;
		for (i = 0; i < SDLA_IODELAY; ++i);
		if (_INB(port) & 0x01)		/* verify */
		{
			/*
			 * Enabling CPU changes functionality of the
			 * control register, so we have to reset its
			 * mirror.
			 */
			_OUTB(port, 0);		/* disable interrupts */
			hw->regs[0] = 0;
		}
		else return -EIO;
		break;

	case SDLA_S503:
		tmp = hw->regs[0] | 0x09;	/* set bits 0 and 3 */
		_OUTB(port, tmp);
		hw->regs[0] = tmp;		/* update mirror */
		for (i = 0; i < SDLA_IODELAY; ++i);
		if (!(_INB(port) & 0x01))	/* verify */
			return -EIO
		;
		break;

	case SDLA_S507:
		tmp = hw->regs[0] | 0x02;
		_OUTB(port, tmp);
		hw->regs[0] = tmp;		/* update mirror */
		for (i = 0; i < SDLA_IODELAY; ++i);
		if (!(_INB(port) & 0x04))	/* verify */
			return -EIO
		;
		break;

	case SDLA_S508:
		tmp = hw->regs[0] | 0x02;
		_OUTB(port, tmp);
		hw->regs[0] = tmp;	/* update mirror */
		for (i = 0; i < SDLA_IODELAY; ++i);
		if (!(_INB(port + 1) & 0x02))	/* verify */
			return -EIO
		;
		break;

	default:
		return -EINVAL;
	}
	return 0;
}

/*============================================================================
 * Initialize S502A adapter.
 */
static int init_s502a (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp, i;

	if (!detect_s502a(port))
		return -ENODEV
	;
	hw->regs[0] = 0x08;
	hw->regs[1] = 0xFF;

	/* Verify configuration options */
	i = get_option_index(s502a_dpmbase_options, hw->dpmbase);
	if (i == 0)
		return -EINVAL
	;

	tmp = s502a_hmcr[i - 1];
	switch (hw->dpmsize)
	{
	case 0x2000:
		tmp |= 0x01;
		break;

	case 0x10000L:
		break;

	default:
		return -EINVAL;
	}

	/* Setup dual-port memory window (this also enables memory access) */
	_OUTB(port + 1, tmp);
	hw->regs[1] = tmp;
	hw->regs[0] = 0x08;
	return 0;
}

/*============================================================================
 * Initialize S502E adapter.
 */
static int init_s502e (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp, i;

	if (!detect_s502e(port))
		return -ENODEV
	;

	/* Verify configuration options */
	i = get_option_index(s508_dpmbase_options, hw->dpmbase);
	if (i == 0)
		return -EINVAL
	;

	tmp = s502e_hmcr[i - 1];
	switch (hw->dpmsize)
	{
	case 0x2000:
		tmp |= 0x01;
		break;

	case 0x10000L:
		break;

	default:
		return -EINVAL;
	}

	/* Setup dual-port memory window */
	_OUTB(port + 1, tmp);
	hw->regs[1] = tmp;

	/* Enable memory access */
	_OUTB(port, 0x02);
	hw->regs[0] = 0x02;
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	return (_INB(port) & 0x02) ? 0 : -EIO;
}

/*============================================================================
 * Initialize S503 adapter.
 * ---------------------------------------------------------------------------
 */
static int init_s503 (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp, i;

	if (!detect_s503(port))
		return -ENODEV
	;

	/* Verify configuration options */
	i = get_option_index(s508_dpmbase_options, hw->dpmbase);
	if (i == 0)
		return -EINVAL
	;

	tmp = s502e_hmcr[i - 1];
	switch (hw->dpmsize)
	{
	case 0x2000:
		tmp |= 0x01;
		break;

	case 0x10000L:
		break;

	default:
		return -EINVAL;
	}

	/* Setup dual-port memory window */
	_OUTB(port + 1, tmp);
	hw->regs[1] = tmp;

	/* Enable memory access */
	_OUTB(port, 0x02);
	hw->regs[0] = 0x02;	/* update mirror */
	return 0;
}

/*============================================================================
 * Initialize S507 adapter.
 */
static int init_s507 (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp, i;

	if (!detect_s507(port))
		return -ENODEV
	;

	/* Verify configuration options */
	i = get_option_index(s507_dpmbase_options, hw->dpmbase);
	if (i == 0)
		return -EINVAL
	;

	tmp = s507_hmcr[i - 1];
	switch (hw->dpmsize)
	{
	case 0x2000:
		tmp |= 0x01;
		break;

	case 0x10000L:
		break;

	default:
		return -EINVAL;
	}

	/* Enable adapter's logic */
	_OUTB(port, 0x01);
	hw->regs[0] = 0x01;
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (!(_INB(port) & 0x20))
		return -EIO
	;

	/* Setup dual-port memory window */
	_OUTB(port + 1, tmp);
	hw->regs[1] = tmp;

	/* Enable memory access */
	tmp = hw->regs[0] | 0x04;
	if (hw->irq)
	{
		i = get_option_index(s508_irq_options, hw->irq);
		if (i) tmp |= s507_irqmask[i - 1];
	}
	_OUTB(port, tmp);
	hw->regs[0] = tmp;		/* update mirror */
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	return (_INB(port) & 0x08) ? 0 : -EIO;
}

/*============================================================================
 * Initialize S508 adapter.
 */
static int init_s508 (sdlahw_t* hw)
{
	unsigned port = hw->port;
	int tmp, i;

	if (!detect_s508(port))
		return -ENODEV
	;

	/* Verify configuration options */
	i = get_option_index(s508_dpmbase_options, hw->dpmbase);
	if (i == 0)
		return -EINVAL
	;

	/* Setup memory configuration */
	tmp = s508_hmcr[i - 1];
	_OUTB(port + 1, tmp);
	hw->regs[1] = tmp;

	/* Enable memory access */
	_OUTB(port, 0x04);
	hw->regs[0] = 0x04;		/* update mirror */
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	return (_INB(port + 1) & 0x04) ? 0 : -EIO;
}

/*============================================================================
 * Detect S502A adapter.
 *	Following tests are used to detect S502A adapter:
 *	1. All registers other than status (BASE) should read 0xFF
 *	2. After writing 00001000b to control register, status register should
 *	   read 01000000b.
 *	3. After writing 0 to control register, status register should still
 *	   read  01000000b.
 *	4. After writing 00000100b to control register, status register should
 *	   read 01000100b.
 *	Return 1 if detected o.k. or 0 if failed.
 *	Note:	This test is destructive! Adapter will be left in shutdown
 *		state after the test.
 */
static int detect_s502a (int port)
{
	int i, j;

	if (!get_option_index(s502_port_options, port))
		return 0
	;
	for (j = 1; j < SDLA_MAXIORANGE; ++j)
	{
		if (_INB(port + j) != 0xFF)
			return 0
		;
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	}

	_OUTB(port, 0x08);			/* halt CPU */
	_OUTB(port, 0x08);
	_OUTB(port, 0x08);
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (_INB(port) != 0x40)
		return 0
	;
	_OUTB(port, 0x00);
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (_INB(port) != 0x40)
		return 0
	;
	_OUTB(port, 0x04);
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (_INB(port) != 0x44)
		return 0
	;

	/* Reset adapter */
	_OUTB(port, 0x08);
	_OUTB(port, 0x08);
	_OUTB(port, 0x08);
	_OUTB(port + 1, 0xFF);
	return 1;
}

/*============================================================================
 * Detect S502E adapter.
 *	Following tests are used to verify adapter presence:
 *	1. All registers other than status (BASE) should read 0xFF.
 *	2. After writing 0 to CPU control register (BASE+3), status register
 *	   (BASE) should read 11111000b.
 *	3. After writing 00000100b to port BASE (set bit 2), status register
 *	   (BASE) should read 11111100b.
 *	Return 1 if detected o.k. or 0 if failed.
 *	Note:	This test is destructive! Adapter will be left in shutdown
 *		state after the test.
 */
static int detect_s502e (int port)
{
	int i, j;

	if (!get_option_index(s502_port_options, port))
		return 0
	;
	for (j = 1; j < SDLA_MAXIORANGE; ++j)
	{
		if (_INB(port + j) != 0xFF)
			return 0
		;
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	}

	_OUTB(port + 3, 0);			/* CPU control reg. */
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (_INB(port) != 0xF8)			/* read status */
		return 0
	;
	_OUTB(port, 0x04);			/* set bit 2 */
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (_INB(port) != 0xFC)			/* verify */
		return 0
	;

	/* Reset adapter */
	_OUTB(port, 0);
	return 1;
}

/*============================================================================
 * Detect s503 adapter.
 *	Following tests are used to verify adapter presence:
 *	1. All registers other than status (BASE) should read 0xFF.
 *	2. After writing 0 to control register (BASE), status register (BASE)
 *	   should read 11110000b.
 *	3. After writing 00000100b (set bit 2) to control register (BASE),
 *	   status register should read 11110010b.
 *	Return 1 if detected o.k. or 0 if failed.
 *	Note:	This test is destructive! Adapter will be left in shutdown
 *		state after the test.
 */
static int detect_s503 (int port)
{
	int i, j;

	if (!get_option_index(s503_port_options, port))
		return 0
	;
	for (j = 1; j < SDLA_MAXIORANGE; ++j)
	{
		if (_INB(port + j) != 0xFF)
			return 0
		;
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	}

	_OUTB(port, 0);				/* reset control reg.*/
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (_INB(port) != 0xF0)			/* read status */
		return 0
	;
	_OUTB(port, 0x04);			/* set bit 2 */
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if (_INB(port) != 0xF2)			/* verify */
		return 0
	;

	/* Reset adapter */
	_OUTB(port, 0);
	return 1;
}

/*============================================================================
 * Detect s507 adapter.
 *	Following tests are used to detect s507 adapter:
 *	1. All ports should read the same value.
 *	2. After writing 0x00 to control register, status register should read
 *	   ?011000?b.
 *	3. After writing 0x01 to control register, status register should read
 *	   ?011001?b.
 *	Return 1 if detected o.k. or 0 if failed.
 *	Note:	This test is destructive! Adapter will be left in shutdown
 *		state after the test.
 */
static int detect_s507 (int port)
{
	int tmp, i, j;

	if (!get_option_index(s508_port_options, port))
		return 0
	;
	tmp = _INB(port);
	for (j = 1; j < S507_IORANGE; ++j)
	{
		if (_INB(port + j) != tmp)
			return 0
		;
		for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	}

	_OUTB(port, 0x00);
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if ((_INB(port) & 0x7E) != 0x30)
		return 0
	;
	_OUTB(port, 0x01);
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if ((_INB(port) & 0x7E) != 0x32)
		return 0
	;

	/* Reset adapter */
	_OUTB(port, 0x00);
	return 1;
}

/*============================================================================
 * Detect s508 adapter.
 *	Following tests are used to detect s508 adapter:
 *	1. After writing 0x00 to control register, status register should read
 *	   ??000000b.
 *	2. After writing 0x10 to control register, status register should read
 *	   ??010000b
 *	Return 1 if detected o.k. or 0 if failed.
 *	Note:	This test is destructive! Adapter will be left in shutdown
 *		state after the test.
 */
static int detect_s508 (int port)
{
	int i;

	if (!get_option_index(s508_port_options, port))
		return 0
	;
	_OUTB(port, 0x00);
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if ((_INB(port + 1) & 0x3F) != 0x00)
		return 0
	;
	_OUTB(port, 0x10);
	for (i = 0; i < SDLA_IODELAY; ++i);	/* delay */
	if ((_INB(port + 1) & 0x3F) != 0x10)
		return 0
	;

	/* Reset adapter */
	_OUTB(port, 0x00);
	return 1;
}

/******* Miscellaneous ******************************************************/

/*============================================================================
 * Calibrate SDLA memory access delay.
 * Count number of idle loops made within 1 second and then calculate the
 * number of loops that should be made to achive desired delay.
 */
static int calibrate_delay (int mks)
{
	unsigned int delay;
	unsigned long stop;

	for (delay = 0, stop = SYSTEM_TICK + HZ; SYSTEM_TICK < stop; ++delay);
	return (delay/(1000000L/mks) + 1);
}

/*============================================================================
 * Get option's index into the options list.
 *	Return option's index (1 .. N) or zero if option is invalid.
 */
static int get_option_index (unsigned* optlist, unsigned optval)
{
	int i;

	for (i = 1; i <= optlist[0]; ++i)
		if (optlist[i] == optval) return i
	;
	return 0;
}

/*============================================================================
 * Check memory region to see if it's available. 
 * Return:	0	ok.
 */
static unsigned check_memregion (void* ptr, unsigned len)
{
	volatile unsigned char* p = ptr;

	for (; len && (*p == 0xFF); --len, ++p)
	{
		*p = 0;			/* attempt to write 0 */
		if (*p != 0xFF)		/* still has to read 0xFF */
		{
			*p = 0xFF;	/* restore original value */
			break;		/* not good */
		}
	}
	return len;
}

/*============================================================================
 * Test memory region.
 * Return:	size of the region that passed the test.
 * Note:	Region size must be multiple of 2 !
 */
static unsigned test_memregion (void* ptr, unsigned len)
{
	volatile unsigned short* w_ptr;
	unsigned len_w = len >> 1;	/* region len in words */
	unsigned i;

	for (i = 0, w_ptr = ptr; i < len_w; ++i, ++w_ptr)
		*w_ptr = 0xAA55
	;
	for (i = 0, w_ptr = ptr; i < len_w; ++i, ++w_ptr)
		if (*w_ptr != 0xAA55)
		{
			len_w = i;
			break;
		}
	;
	for (i = 0, w_ptr = ptr; i < len_w; ++i, ++w_ptr)
		*w_ptr = 0x55AA
	;
	for (i = 0, w_ptr = ptr; i < len_w; ++i, ++w_ptr)
		if (*w_ptr != 0x55AA)
		{
			len_w = i;
			break;
		}
	;
	for (i = 0, w_ptr = ptr; i < len_w; ++i, ++w_ptr) *w_ptr = 0;
	return len_w << 1;
}

/*============================================================================
 * Calculate 16-bit CRC using CCITT polynomial.
 */
static unsigned short checksum (unsigned char* buf, unsigned len)
{
	unsigned short crc = 0;
	unsigned mask, flag;

	for (; len; --len, ++buf)
	{
		for (mask = 0x80; mask; mask >>= 1)
		{
			flag = (crc & 0x8000);
			crc <<= 1;
			crc |= ((*buf & mask) ? 1 : 0);
			if (flag) crc ^= 0x1021;
		}
	}
	return crc;
}


/****** End *****************************************************************/