/*
 * This driver adapted from Drew Eckhardt's Trantor T128 driver
 *
 * Copyright 1993, Drew Eckhardt
 *      Visionary Computing
 *      (Unix and Linux consulting and custom programming)
 *      drew@colorado.edu
 *      +1 (303) 666-5836
 *
 *  ( Based on T128 - DISTRIBUTION RELEASE 3. ) 
 *
 * Modified to work with the Pro Audio Spectrum/Studio 16
 * by John Weidman.
 *
 *
 * For more information, please consult 
 *
 * Media Vision
 * (510) 770-8600
 * (800) 348-7116
 */

/*
 * The card is detected and initialized in one of several ways : 
 * 1.  Autoprobe (default) - There are many different models of
 *     the Pro Audio Spectrum/Studio 16, and I only have one of
 *     them, so this may require a little tweaking.  An interrupt
 *     is triggered to autoprobe for the interrupt line.  Note:
 *     with the newer model boards, the interrupt is set via
 *     software after reset using the default_irq for the
 *     current board number.
 *
 * 2.  With command line overrides - pas16=port,irq may be 
 *     used on the LILO command line to override the defaults.
 *
 * 3.  With the PAS16_OVERRIDE compile time define.  This is 
 *     specified as an array of address, irq tuples.  Ie, for
 *     one board at the default 0x388 address, IRQ10, I could say 
 *     -DPAS16_OVERRIDE={{0x388, 10}}
 *     NOTE:  Untested.
 *      
 * 4.  When included as a module, with arguments passed on the command line:
 *         pas16_irq=xx         the interrupt
 *         pas16_addr=xx        the port
 *     e.g. "modprobe pas16 pas16_addr=0x388 pas16_irq=5"
 *
 *     Note that if the override methods are used, place holders must
 *     be specified for other boards in the system.
 *
 *
 * Configuration notes :
 *   The current driver does not support interrupt sharing with the
 *   sound portion of the card.  If you use the same irq for the
 *   scsi port and sound you will have problems.  Either use
 *   a different irq for the scsi port or don't use interrupts
 *   for the scsi port.
 *
 *   If you have problems with your card not being recognized, use
 *   the LILO command line override.  Try to get it recognized without
 *   interrupts.  Ie, for a board at the default 0x388 base port,
 *   boot: linux pas16=0x388,0
 *
 *   NO_IRQ (0) should be specified for no interrupt,
 *   IRQ_AUTO (254) to autoprobe for an IRQ line if overridden
 *   on the command line.
 */
 
#include <linux/module.h>

#include <asm/io.h>
#include <asm/dma.h>
#include <linux/blkdev.h>
#include <linux/interrupt.h>
#include <linux/init.h>

#include <scsi/scsi_host.h>
#include "pas16.h"
#include "NCR5380.h"


static unsigned short pas16_addr;
static int pas16_irq;
 

static const int scsi_irq_translate[] =
        { 0,  0,  1,  2,  3,  4,  5,  6, 0,  0,  7,  8,  9,  0, 10, 11 };

/* The default_irqs array contains values used to set the irq into the
 * board via software (as must be done on newer model boards without
 * irq jumpers on the board).  The first value in the array will be
 * assigned to logical board 0, the next to board 1, etc.
 */
static int default_irqs[] __initdata =
        {  PAS16_DEFAULT_BOARD_1_IRQ,
           PAS16_DEFAULT_BOARD_2_IRQ,
           PAS16_DEFAULT_BOARD_3_IRQ,
           PAS16_DEFAULT_BOARD_4_IRQ
        };

static struct override {
    unsigned short io_port;
    int  irq;
} overrides
#ifdef PAS16_OVERRIDE
    [] __initdata = PAS16_OVERRIDE;
#else
    [4] __initdata = {{0,IRQ_AUTO}, {0,IRQ_AUTO}, {0,IRQ_AUTO},
        {0,IRQ_AUTO}};
#endif

#define NO_OVERRIDES ARRAY_SIZE(overrides)

static struct base {
    unsigned short io_port;
    int noauto;
} bases[] __initdata =
        { {PAS16_DEFAULT_BASE_1, 0},
          {PAS16_DEFAULT_BASE_2, 0},
          {PAS16_DEFAULT_BASE_3, 0},
          {PAS16_DEFAULT_BASE_4, 0}
        };

#define NO_BASES ARRAY_SIZE(bases)

static const unsigned short  pas16_offset[ 8 ] =
    {
        0x1c00,    /* OUTPUT_DATA_REG */
        0x1c01,    /* INITIATOR_COMMAND_REG */
        0x1c02,    /* MODE_REG */
        0x1c03,    /* TARGET_COMMAND_REG */
        0x3c00,    /* STATUS_REG ro, SELECT_ENABLE_REG wo */
        0x3c01,    /* BUS_AND_STATUS_REG ro, START_DMA_SEND_REG wo */
        0x3c02,    /* INPUT_DATA_REGISTER ro, (N/A on PAS16 ?)
                    * START_DMA_TARGET_RECEIVE_REG wo
                    */
        0x3c03,    /* RESET_PARITY_INTERRUPT_REG ro,
                    * START_DMA_INITIATOR_RECEIVE_REG wo
                    */
    };


/*
 * Function : enable_board( int  board_num, unsigned short port )
 *
 * Purpose :  set address in new model board
 *
 * Inputs : board_num - logical board number 0-3, port - base address
 *
 */

static void __init
        enable_board( int  board_num,  unsigned short port )
{
    outb( 0xbc + board_num, MASTER_ADDRESS_PTR );
    outb( port >> 2, MASTER_ADDRESS_PTR );
}



/*
 * Function : init_board( unsigned short port, int irq )
 *
 * Purpose :  Set the board up to handle the SCSI interface
 *
 * Inputs : port - base address of the board,
 *          irq - irq to assign to the SCSI port
 *          force_irq - set it even if it conflicts with sound driver
 *
 */

static void __init 
        init_board( unsigned short io_port, int irq, int force_irq )
{
        unsigned int    tmp;
        unsigned int    pas_irq_code;

        /* Initialize the SCSI part of the board */

        outb( 0x30, io_port + P_TIMEOUT_COUNTER_REG );  /* Timeout counter */
        outb( 0x01, io_port + P_TIMEOUT_STATUS_REG_OFFSET );   /* Reset TC */
        outb( 0x01, io_port + WAIT_STATE );   /* 1 Wait state */

        inb(io_port + pas16_offset[RESET_PARITY_INTERRUPT_REG]);

        /* Set the SCSI interrupt pointer without mucking up the sound
         * interrupt pointer in the same byte.
         */
        pas_irq_code = ( irq < 16 ) ? scsi_irq_translate[irq] : 0;
        tmp = inb( io_port + IO_CONFIG_3 );

        if( (( tmp & 0x0f ) == pas_irq_code) && pas_irq_code > 0 
            && !force_irq )
        {
            printk( "pas16: WARNING: Can't use same irq as sound "
                    "driver -- interrupts disabled\n" );
            /* Set up the drive parameters, disable 5380 interrupts */
            outb( 0x4d, io_port + SYS_CONFIG_4 );
        }
        else
        {
            tmp = (  tmp & 0x0f ) | ( pas_irq_code << 4 );
            outb( tmp, io_port + IO_CONFIG_3 );

            /* Set up the drive parameters and enable 5380 interrupts */
            outb( 0x6d, io_port + SYS_CONFIG_4 );
        }
}


/*
 * Function : pas16_hw_detect( unsigned short board_num )
 *
 * Purpose : determine if a pas16 board is present
 * 
 * Inputs : board_num - logical board number ( 0 - 3 )
 *
 * Returns : 0 if board not found, 1 if found.
 */

static int __init 
     pas16_hw_detect( unsigned short  board_num )
{
    unsigned char       board_rev, tmp;
    unsigned short      io_port = bases[ board_num ].io_port;

    /* See if we can find a PAS16 board at the address associated
     * with this logical board number.
     */

    /* First, attempt to take a newer model board out of reset and
     * give it a base address.  This shouldn't affect older boards.
     */
    enable_board( board_num, io_port );

    /* Now see if it looks like a PAS16 board */
    board_rev = inb( io_port + PCB_CONFIG );

    if( board_rev == 0xff )
        return 0;

    tmp = board_rev ^ 0xe0;

    outb( tmp, io_port + PCB_CONFIG );
    tmp = inb( io_port + PCB_CONFIG );
    outb( board_rev, io_port + PCB_CONFIG );

    if( board_rev != tmp )      /* Not a PAS-16 */
        return 0;

    if( ( inb( io_port + OPERATION_MODE_1 ) & 0x03 ) != 0x03 ) 
        return 0;       /* return if no SCSI interface found */

    /* Mediavision has some new model boards that return ID bits
     * that indicate a SCSI interface, but they're not (LMS).  We'll
     * put in an additional test to try to weed them out.
     */

        outb(0x01, io_port + WAIT_STATE);             /* 1 Wait state */
        outb(0x20, io_port + pas16_offset[MODE_REG]); /* Is it really SCSI? */
        if (inb(io_port + pas16_offset[MODE_REG]) != 0x20) /* Write to a reg. */
                return 0;                                  /* and try to read */
        outb(0x00, io_port + pas16_offset[MODE_REG]);      /* it back. */
        if (inb(io_port + pas16_offset[MODE_REG]) != 0x00)
                return 0;

    return 1;
}


#ifndef MODULE
/*
 * Function : pas16_setup(char *str, int *ints)
 *
 * Purpose : LILO command line initialization of the overrides array,
 * 
 * Inputs : str - unused, ints - array of integer parameters with ints[0]
 *      equal to the number of ints.
 *
 */

static int __init pas16_setup(char *str)
{
        static int commandline_current;
    int i;
    int ints[10];

    get_options(str, ARRAY_SIZE(ints), ints);
    if (ints[0] != 2) 
        printk("pas16_setup : usage pas16=io_port,irq\n");
    else 
        if (commandline_current < NO_OVERRIDES) {
            overrides[commandline_current].io_port = (unsigned short) ints[1];
            overrides[commandline_current].irq = ints[2];
            for (i = 0; i < NO_BASES; ++i)
                if (bases[i].io_port == (unsigned short) ints[1]) {
                    bases[i].noauto = 1;
                    break;
                }
            ++commandline_current;
        }
    return 1;
}

__setup("pas16=", pas16_setup);
#endif

/* 
 * Function : int pas16_detect(struct scsi_host_template * tpnt)
 *
 * Purpose : detects and initializes PAS16 controllers
 *      that were autoprobed, overridden on the LILO command line, 
 *      or specified at compile time.
 *
 * Inputs : tpnt - template for this SCSI adapter.
 * 
 * Returns : 1 if a host adapter was found, 0 if not.
 *
 */

static int __init pas16_detect(struct scsi_host_template *tpnt)
{
        static int current_override;
        static unsigned short current_base;
    struct Scsi_Host *instance;
    unsigned short io_port;
    int  count;

    if (pas16_addr != 0) {
        overrides[0].io_port = pas16_addr;
        /*
        *  This is how we avoid seeing more than
        *  one host adapter at the same I/O port.
        *  Cribbed shamelessly from pas16_setup().
        */
        for (count = 0; count < NO_BASES; ++count)
            if (bases[count].io_port == pas16_addr) {
                    bases[count].noauto = 1;
                    break;
        }
    }
    if (pas16_irq != 0)
        overrides[0].irq = pas16_irq;

    for (count = 0; current_override < NO_OVERRIDES; ++current_override) {
        io_port = 0;

        if (overrides[current_override].io_port)
        {
            io_port = overrides[current_override].io_port;
            enable_board( current_override, io_port );
            init_board( io_port, overrides[current_override].irq, 1 );
        }
        else
            for (; !io_port && (current_base < NO_BASES); ++current_base) {
                dprintk(NDEBUG_INIT, "pas16: probing io_port 0x%04x\n",
                        (unsigned int)bases[current_base].io_port);
                if ( !bases[current_base].noauto &&
                     pas16_hw_detect( current_base ) ){
                        io_port = bases[current_base].io_port;
                        init_board( io_port, default_irqs[ current_base ], 0 ); 
                        dprintk(NDEBUG_INIT, "pas16: detected board\n");
                }
    }

        dprintk(NDEBUG_INIT, "pas16: io_port = 0x%04x\n",
                (unsigned int)io_port);

        if (!io_port)
            break;

        instance = scsi_register (tpnt, sizeof(struct NCR5380_hostdata));
        if(instance == NULL)
                goto out;
                
        instance->io_port = io_port;

        if (NCR5380_init(instance, FLAG_DMA_FIXUP | FLAG_LATE_DMA_SETUP))
                goto out_unregister;

        NCR5380_maybe_reset_bus(instance);

        if (overrides[current_override].irq != IRQ_AUTO)
            instance->irq = overrides[current_override].irq;
        else 
            instance->irq = NCR5380_probe_irq(instance, PAS16_IRQS);

        /* Compatibility with documented NCR5380 kernel parameters */
        if (instance->irq == 255)
                instance->irq = NO_IRQ;

        if (instance->irq != NO_IRQ)
            if (request_irq(instance->irq, pas16_intr, 0,
                            "pas16", instance)) {
                printk("scsi%d : IRQ%d not free, interrupts disabled\n", 
                    instance->host_no, instance->irq);
                instance->irq = NO_IRQ;
            } 

        if (instance->irq == NO_IRQ) {
            printk("scsi%d : interrupts not enabled. for better interactive performance,\n", instance->host_no);
            printk("scsi%d : please jumper the board for a free IRQ.\n", instance->host_no);
            /* Disable 5380 interrupts, leave drive params the same */
            outb( 0x4d, io_port + SYS_CONFIG_4 );
            outb( (inb(io_port + IO_CONFIG_3) & 0x0f), io_port + IO_CONFIG_3 );
        }

        dprintk(NDEBUG_INIT, "scsi%d : irq = %d\n",
                instance->host_no, instance->irq);

        ++current_override;
        ++count;
    }
    return count;

out_unregister:
        scsi_unregister(instance);
out:
        return count;
}

/*
 * Function : int pas16_biosparam(Disk *disk, struct block_device *dev, int *ip)
 *
 * Purpose : Generates a BIOS / DOS compatible H-C-S mapping for 
 *      the specified device / size.
 * 
 * Inputs : size = size of device in sectors (512 bytes), dev = block device
 *      major / minor, ip[] = {heads, sectors, cylinders}  
 *
 * Returns : always 0 (success), initializes ip
 *      
 */

/* 
 * XXX Most SCSI boards use this mapping, I could be incorrect.  Some one
 * using hard disks on a trantor should verify that this mapping corresponds
 * to that used by the BIOS / ASPI driver by running the linux fdisk program
 * and matching the H_C_S coordinates to what DOS uses.
 */

static int pas16_biosparam(struct scsi_device *sdev, struct block_device *dev,
                           sector_t capacity, int *ip)
{
  int size = capacity;
  ip[0] = 64;
  ip[1] = 32;
  ip[2] = size >> 11;           /* I think I have it as /(32*64) */
  if( ip[2] > 1024 ) {          /* yes, >, not >= */
        ip[0]=255;
        ip[1]=63;
        ip[2]=size/(63*255);
        if( ip[2] > 1023 )      /* yes >1023... */
                ip[2] = 1023;
  }

  return 0;
}

/*
 * Function : int pas16_pread (struct Scsi_Host *instance,
 *      unsigned char *dst, int len)
 *
 * Purpose : Fast 5380 pseudo-dma read function, transfers len bytes to 
 *      dst
 * 
 * Inputs : dst = destination, len = length in bytes
 *
 * Returns : 0 on success, non zero on a failure such as a watchdog 
 *      timeout.
 */

static inline int pas16_pread(struct Scsi_Host *instance,
                              unsigned char *dst, int len)
{
    register unsigned char  *d = dst;
    register unsigned short reg = (unsigned short) (instance->io_port + 
        P_DATA_REG_OFFSET);
    register int i = len;
    int ii = 0;

    while ( !(inb(instance->io_port + P_STATUS_REG_OFFSET) & P_ST_RDY) )
         ++ii;

    insb( reg, d, i );

    if ( inb(instance->io_port + P_TIMEOUT_STATUS_REG_OFFSET) & P_TS_TIM) {
        outb( P_TS_CT, instance->io_port + P_TIMEOUT_STATUS_REG_OFFSET);
        printk("scsi%d : watchdog timer fired in NCR5380_pread()\n",
            instance->host_no);
        return -1;
    }
    return 0;
}

/*
 * Function : int pas16_pwrite (struct Scsi_Host *instance,
 *      unsigned char *src, int len)
 *
 * Purpose : Fast 5380 pseudo-dma write function, transfers len bytes from
 *      src
 * 
 * Inputs : src = source, len = length in bytes
 *
 * Returns : 0 on success, non zero on a failure such as a watchdog 
 *      timeout.
 */

static inline int pas16_pwrite(struct Scsi_Host *instance,
                               unsigned char *src, int len)
{
    register unsigned char *s = src;
    register unsigned short reg = (instance->io_port + P_DATA_REG_OFFSET);
    register int i = len;
    int ii = 0;

    while ( !((inb(instance->io_port + P_STATUS_REG_OFFSET)) & P_ST_RDY) )
         ++ii;
 
    outsb( reg, s, i );

    if (inb(instance->io_port + P_TIMEOUT_STATUS_REG_OFFSET) & P_TS_TIM) {
        outb( P_TS_CT, instance->io_port + P_TIMEOUT_STATUS_REG_OFFSET);
        printk("scsi%d : watchdog timer fired in NCR5380_pwrite()\n",
            instance->host_no);
        return -1;
    }
    return 0;
}

#include "NCR5380.c"

static int pas16_release(struct Scsi_Host *shost)
{
        if (shost->irq != NO_IRQ)
                free_irq(shost->irq, shost);
        NCR5380_exit(shost);
        scsi_unregister(shost);
        return 0;
}

static struct scsi_host_template driver_template = {
        .name                   = "Pro Audio Spectrum-16 SCSI",
        .detect                 = pas16_detect,
        .release                = pas16_release,
        .proc_name              = "pas16",
        .info                   = pas16_info,
        .queuecommand           = pas16_queue_command,
        .eh_abort_handler       = pas16_abort,
        .eh_bus_reset_handler   = pas16_bus_reset,
        .bios_param             = pas16_biosparam,
        .can_queue              = 32,
        .this_id                = 7,
        .sg_tablesize           = SG_ALL,
        .cmd_per_lun            = 2,
        .use_clustering         = DISABLE_CLUSTERING,
        .cmd_size               = NCR5380_CMD_SIZE,
        .max_sectors            = 128,
};
#include "scsi_module.c"

#ifdef MODULE
module_param(pas16_addr, ushort, 0);
module_param(pas16_irq, int, 0);
#endif
MODULE_LICENSE("GPL");