/* -- ISP16 cdrom detection and configuration
 *
 *    Copyright (c) 1995,1996 Eric van der Maarel <H.T.M.v.d.Maarel@marin.nl>
 *
 *    Version 0.6
 *
 *    History:
 *    0.5 First release.
 *        Was included in the sjcd and optcd cdrom drivers.
 *    0.6 First "stand-alone" version.
 *        Removed sound configuration.
 *        Added "module" support.
 *
 *    Detect cdrom interface on ISP16 sound card.
 *    Configure cdrom interface.
 *
 *    Algorithm for the card with OPTi 82C928 taken
 *    from the CDSETUP.SYS driver for MSDOS,
 *    by OPTi Computers, version 2.03.
 *    Algorithm for the card with OPTi 82C929 as communicated
 *    to me by Vadim Model and Leo Spiekman.
 *
 *    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.
 *
 *    This program is distributed in the hope that it will be useful,
 *    but WITHOUT ANY WARRANTY; without even the implied warranty of
 *    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *    GNU General Public License for more details.
 *
 *    You should have received a copy of the GNU General Public License
 *    along with this program; if not, write to the Free Software
 *    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 */

#define ISP16_VERSION_MAJOR 0
#define ISP16_VERSION_MINOR 6

#ifdef MODULE
#include <linux/module.h>
#endif  /* MODULE */

#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/isp16.h>
#include <asm/io.h>

static short isp16_detect(void);
static short isp16_c928__detect(void);
static short isp16_c929__detect(void);
static short isp16_cdi_config(int base, u_char drive_type, int irq, int dma);
static short isp16_type; /* dependent on type of interface card */
static u_char isp16_ctrl;
static u_short isp16_enable_port;

static int isp16_cdrom_base = ISP16_CDROM_IO_BASE;
static int isp16_cdrom_irq = ISP16_CDROM_IRQ;
static int isp16_cdrom_dma = ISP16_CDROM_DMA;
static char *isp16_cdrom_type = ISP16_CDROM_TYPE;

#ifdef MODULE
MODULE_PARM(isp16_cdrom_base, "i");
MODULE_PARM(isp16_cdrom_irq, "i");
MODULE_PARM(isp16_cdrom_dma, "i");
MODULE_PARM(isp16_cdrom_type, "s");
int init_module(void);
void cleanup_module(void);
#endif

#define ISP16_IN(p) (outb(isp16_ctrl,ISP16_CTRL_PORT), inb(p))
#define ISP16_OUT(p,b) (outb(isp16_ctrl,ISP16_CTRL_PORT), outb(b,p))


void
isp16_setup(char *str, int *ints)
{
  if ( ints[0] > 0 )
    isp16_cdrom_base = ints[1];
  if ( ints[0] > 1 )      
    isp16_cdrom_irq = ints[2];
  if ( ints[0] > 2 )      
    isp16_cdrom_dma = ints[3];
  if ( str )
    isp16_cdrom_type = str;
}

/*
 *  ISP16 initialisation.
 *
 */
int
isp16_init(void)
{
  u_char expected_drive;

  printk(KERN_INFO "ISP16: configuration cdrom interface, version %d.%d.\n", ISP16_VERSION_MAJOR,
    ISP16_VERSION_MINOR);

  if ( !strcmp(isp16_cdrom_type, "noisp16") ) {
    printk("ISP16: no cdrom interface configured.\n");
    return(0);
  }

  if (check_region(ISP16_IO_BASE, ISP16_IO_SIZE)) {
    printk("ISP16: i/o ports already in use.\n");
    return(-EIO);
  }

  if ( (isp16_type=isp16_detect()) < 0 ) {
    printk("ISP16: no cdrom interface found.\n");
    return(-EIO);
  }

  printk(KERN_INFO "ISP16: cdrom interface (with OPTi 82C92%d chip) detected.\n",
    (isp16_type==2) ? 9 : 8);

  if ( !strcmp(isp16_cdrom_type, "Sanyo") )
    expected_drive = (isp16_type ? ISP16_SANYO1 : ISP16_SANYO0);
  else if ( !strcmp(isp16_cdrom_type, "Sony") )
    expected_drive = ISP16_SONY;
  else if ( !strcmp(isp16_cdrom_type, "Panasonic") )
    expected_drive = (isp16_type ? ISP16_PANASONIC1 : ISP16_PANASONIC0);
  else if ( !strcmp(isp16_cdrom_type, "Mitsumi") )
    expected_drive = ISP16_MITSUMI;
  else {
    printk("ISP16: %s not supported by cdrom interface.\n", isp16_cdrom_type);
    return(-EIO);
  }

  if ( isp16_cdi_config(isp16_cdrom_base, expected_drive,
    isp16_cdrom_irq, isp16_cdrom_dma ) < 0) {
    printk("ISP16: cdrom interface has not been properly configured.\n");
    return(-EIO);
  }
  printk(KERN_INFO "ISP16: cdrom interface set up with io base 0x%03X, irq %d, dma %d,"
    " type %s.\n", isp16_cdrom_base, isp16_cdrom_irq, isp16_cdrom_dma,
    isp16_cdrom_type);
  return(0);
}

static short
isp16_detect(void)
{

  if ( isp16_c929__detect() >= 0 )
    return(2);
  else
    return(isp16_c928__detect());
}

static short
isp16_c928__detect(void)
{
  u_char ctrl;
  u_char enable_cdrom;
  u_char io;
  short i = -1;

  isp16_ctrl = ISP16_C928__CTRL;
  isp16_enable_port = ISP16_C928__ENABLE_PORT;

  /* read' and write' are a special read and write, respectively */

  /* read' ISP16_CTRL_PORT, clear last two bits and write' back the result */
  ctrl = ISP16_IN( ISP16_CTRL_PORT ) & 0xFC;
  ISP16_OUT( ISP16_CTRL_PORT, ctrl );

  /* read' 3,4 and 5-bit from the cdrom enable port */
  enable_cdrom = ISP16_IN( ISP16_C928__ENABLE_PORT ) & 0x38;

  if ( !(enable_cdrom & 0x20) ) {  /* 5-bit not set */
    /* read' last 2 bits of ISP16_IO_SET_PORT */
    io = ISP16_IN( ISP16_IO_SET_PORT ) & 0x03;
    if ( ((io&0x01)<<1) == (io&0x02) ) {  /* bits are the same */
      if ( io == 0 ) {  /* ...the same and 0 */
        i = 0;
        enable_cdrom |= 0x20;
      }
      else {  /* ...the same and 1 */  /* my card, first time 'round */
        i = 1;
        enable_cdrom |= 0x28;
      }
      ISP16_OUT( ISP16_C928__ENABLE_PORT, enable_cdrom );
    }
    else {  /* bits are not the same */
      ISP16_OUT( ISP16_CTRL_PORT, ctrl );
      return(i); /* -> not detected: possibly incorrect conclusion */
    }
  }
  else if ( enable_cdrom == 0x20 )
    i = 0;
  else if ( enable_cdrom == 0x28 )  /* my card, already initialised */
    i = 1;

  ISP16_OUT( ISP16_CTRL_PORT, ctrl );

  return(i);
}

static short
isp16_c929__detect(void)
{
  u_char ctrl;
  u_char tmp;

  isp16_ctrl = ISP16_C929__CTRL;
  isp16_enable_port = ISP16_C929__ENABLE_PORT;

  /* read' and write' are a special read and write, respectively */

  /* read' ISP16_CTRL_PORT and save */
  ctrl = ISP16_IN( ISP16_CTRL_PORT );

  /* write' zero to the ctrl port and get response */
  ISP16_OUT( ISP16_CTRL_PORT, 0 );
  tmp = ISP16_IN( ISP16_CTRL_PORT );

  if ( tmp != 2 )  /* isp16 with 82C929 not detected */
    return(-1);

  /* restore ctrl port value */
  ISP16_OUT( ISP16_CTRL_PORT, ctrl );
  
  return(2);
}

static short
isp16_cdi_config(int base, u_char drive_type, int irq, int dma)
{
  u_char base_code;
  u_char irq_code;
  u_char dma_code;
  u_char i;

  if ( (drive_type == ISP16_MITSUMI) && (dma != 0) )
    printk("ISP16: Mitsumi cdrom drive has no dma support.\n");

  switch (base) {
  case 0x340: base_code = ISP16_BASE_340; break;
  case 0x330: base_code = ISP16_BASE_330; break;
  case 0x360: base_code = ISP16_BASE_360; break;
  case 0x320: base_code = ISP16_BASE_320; break;
  default:
    printk("ISP16: base address 0x%03X not supported by cdrom interface.\n",
      base);
    return(-1);
  }
  switch (irq) {
  case 0: irq_code = ISP16_IRQ_X; break; /* disable irq */
  case 5: irq_code = ISP16_IRQ_5;
          printk("ISP16: irq 5 shouldn't be used by cdrom interface,"
            " due to possible conflicts with the sound card.\n");
          break;
  case 7: irq_code = ISP16_IRQ_7;
          printk("ISP16: irq 7 shouldn't be used by cdrom interface,"
            " due to possible conflicts with the sound card.\n");
          break;
  case 3: irq_code = ISP16_IRQ_3; break;
  case 9: irq_code = ISP16_IRQ_9; break;
  case 10: irq_code = ISP16_IRQ_10; break;
  case 11: irq_code = ISP16_IRQ_11; break;
  default:
    printk("ISP16: irq %d not supported by cdrom interface.\n", irq );
    return(-1);
  }
  switch (dma) {
  case 0: dma_code = ISP16_DMA_X; break;  /* disable dma */
  case 1: printk("ISP16: dma 1 cannot be used by cdrom interface,"
            " due to conflict with the sound card.\n");
          return(-1); break;
  case 3: dma_code = ISP16_DMA_3; break;
  case 5: dma_code = ISP16_DMA_5; break;
  case 6: dma_code = ISP16_DMA_6; break;
  case 7: dma_code = ISP16_DMA_7; break;
  default:
    printk("ISP16: dma %d not supported by cdrom interface.\n", dma);
    return(-1);
  }

  if ( drive_type != ISP16_SONY && drive_type != ISP16_PANASONIC0 &&
    drive_type != ISP16_PANASONIC1 && drive_type != ISP16_SANYO0 &&
    drive_type != ISP16_SANYO1 && drive_type != ISP16_MITSUMI &&
    drive_type != ISP16_DRIVE_X ) {
    printk("ISP16: drive type (code 0x%02X) not supported by cdrom"
     " interface.\n", drive_type );
    return(-1);
  }

  /* set type of interface */
  i = ISP16_IN(ISP16_DRIVE_SET_PORT) & ISP16_DRIVE_SET_MASK;  /* clear some bits */
  ISP16_OUT( ISP16_DRIVE_SET_PORT, i|drive_type );

  /* enable cdrom on interface with 82C929 chip */
  if ( isp16_type > 1 )
    ISP16_OUT( isp16_enable_port, ISP16_ENABLE_CDROM );

  /* set base address, irq and dma */
  i = ISP16_IN(ISP16_IO_SET_PORT) & ISP16_IO_SET_MASK;  /* keep some bits */
  ISP16_OUT( ISP16_IO_SET_PORT, i|base_code|irq_code|dma_code );

  return(0);
}

#ifdef MODULE
int init_module(void)
{
  return isp16_init();
}

void cleanup_module(void)
{
	release_region(ISP16_IO_BASE, ISP16_IO_SIZE);
	printk(KERN_INFO "ISP16: module released.\n");
}
#endif /* MODULE */
