sjcd.c

讲述linux的初始化过程

    if( !sjcd_command_failed ){
      if( sjcd_load_response( &sjcd_table_of_contents[ i ],
			     sizeof( struct sjcd_hw_disk_info ) ) != 0 ){
	printk( "SJCD: cannot load info for %d track\n", i );
	return( -1 );
      }
    } else {
      printk( "SJCD: get info %d failed\n", i );
      return( -1 );
    }
  }

  /*
   * Get the disk length info.
   */
  sjcd_send_1_cmd( SCMD_GET_DISK_INFO, SCMD_GET_D_SIZE );
  sjcd_receive_status();

  if( !sjcd_status_valid ){
    printk( "SJCD: cannot load status.\n" );
    return( -1 );
  }

  if( !sjcd_media_is_available ){
    printk( "SJCD: no disk in drive\n" );
    return( -1 );
  }

  if( !sjcd_command_failed ){
    if( sjcd_load_response( &info, sizeof( info ) ) != 0 ){
      printk( "SJCD: cannot load response about disk size.\n" );
      return( -1 );
    }
    sjcd_disk_length.min = info.un.track_msf.min;
    sjcd_disk_length.sec = info.un.track_msf.sec;
    sjcd_disk_length.frame = info.un.track_msf.frame;
  } else {
    printk( "SJCD: get size failed\n" );
    return( 1 );
  }
#if defined( SJCD_TRACE )
  printk( "SJCD: (%02x:%02x.%02x)\n", sjcd_disk_length.min,
	 sjcd_disk_length.sec, sjcd_disk_length.frame );
#endif
  return( 0 );
}

/*
 * Load subchannel information.
 */
static int sjcd_get_q_info( struct sjcd_hw_qinfo *qp ){
  int s;
#if defined( SJCD_TRACE )
  printk( "SJCD: load sub q\n" );
#endif
  sjcd_send_cmd( SCMD_GET_QINFO );
  s = sjcd_receive_status();
  if( s < 0 || sjcd_command_failed || !sjcd_status_valid ){
    sjcd_send_cmd( 0xF2 );
    s = sjcd_receive_status();
    if( s < 0 || sjcd_command_failed || !sjcd_status_valid ) return( -1 );
    sjcd_send_cmd( SCMD_GET_QINFO );
    s = sjcd_receive_status();
    if( s < 0 || sjcd_command_failed || !sjcd_status_valid ) return( -1 );
  }
  if( sjcd_media_is_available )
    if( sjcd_load_response( qp, sizeof( *qp ) ) == 0 ) return( 0 );
  return( -1 );
}

/*
 * Start playing from the specified position.
 */
static int sjcd_play( struct sjcd_play_msf *mp ){
  struct sjcd_play_msf msf;

  /*
   * Turn the device to play mode.
   */
  sjcd_send_1_cmd( SCMD_SET_MODE, SCMD_MODE_PLAY );
  if( sjcd_receive_status() < 0 ) return( -1 );

  /*
   * Seek to the starting point.
   */
  msf.start = mp->start;
  msf.end.min = msf.end.sec = msf.end.frame = 0x00;
  sjcd_send_6_cmd( SCMD_SEEK, &msf );
  if( sjcd_receive_status() < 0 ) return( -1 );

  /*
   * Start playing.
   */
  sjcd_send_6_cmd( SCMD_PLAY, mp );
  return( sjcd_receive_status() );
}

/*
 * Tray control functions.
 */
static int sjcd_tray_close( void ){
#if defined( SJCD_TRACE )
  printk( "SJCD: tray_close\n" );
#endif
  sjcd_send_cmd( SCMD_CLOSE_TRAY );
  return( sjcd_receive_status() );
}

static int sjcd_tray_lock( void ){
#if defined( SJCD_TRACE )
  printk( "SJCD: tray_lock\n" );
#endif
  sjcd_send_cmd( SCMD_LOCK_TRAY );
  return( sjcd_receive_status() );
}

static int sjcd_tray_unlock( void ){
#if defined( SJCD_TRACE )
  printk( "SJCD: tray_unlock\n" );
#endif
  sjcd_send_cmd( SCMD_UNLOCK_TRAY );
  return( sjcd_receive_status() );
}

static int sjcd_tray_open( void ){
#if defined( SJCD_TRACE )
  printk( "SJCD: tray_open\n" );
#endif
  sjcd_send_cmd( SCMD_EJECT_TRAY );
  return( sjcd_receive_status() );
}

/*
 * Do some user commands.
 */
static int sjcd_ioctl( struct inode *ip, struct file *fp,
		       unsigned int cmd, unsigned long arg ){
#if defined( SJCD_TRACE )
  printk( "SJCD:ioctl\n" );
#endif

  if( ip == NULL ) return( -EINVAL );

  sjcd_get_status();
  if( !sjcd_status_valid ) return( -EIO );
  if( sjcd_update_toc() < 0 ) return( -EIO );

  switch( cmd ){
  case CDROMSTART:{
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: start\n" );
#endif
    return( 0 );
  }

  case CDROMSTOP:{
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: stop\n" );
#endif
    sjcd_send_cmd( SCMD_PAUSE );
    ( void )sjcd_receive_status();
    sjcd_audio_status = CDROM_AUDIO_NO_STATUS;
    return( 0 );
  }

  case CDROMPAUSE:{
    struct sjcd_hw_qinfo q_info;
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: pause\n" );
#endif
    if( sjcd_audio_status == CDROM_AUDIO_PLAY ){
      sjcd_send_cmd( SCMD_PAUSE );
      ( void )sjcd_receive_status();
      if( sjcd_get_q_info( &q_info ) < 0 ){
	sjcd_audio_status = CDROM_AUDIO_NO_STATUS;
      } else {
	sjcd_audio_status = CDROM_AUDIO_PAUSED;
	sjcd_playing.start = q_info.abs;
      }
      return( 0 );
    } else return( -EINVAL );
  }

  case CDROMRESUME:{
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: resume\n" );
#endif
    if( sjcd_audio_status == CDROM_AUDIO_PAUSED ){
      /*
       * continue play starting at saved location
       */
      if( sjcd_play( &sjcd_playing ) < 0 ){
	sjcd_audio_status = CDROM_AUDIO_ERROR;
	return( -EIO );
      } else {
	sjcd_audio_status = CDROM_AUDIO_PLAY;
	return( 0 );
      }
    } else return( -EINVAL );
  }

  case CDROMPLAYTRKIND:{
    struct cdrom_ti ti; int s;
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: playtrkind\n" );
#endif
    if( ( s = verify_area( VERIFY_READ, (void *)arg, sizeof( ti ) ) ) == 0 ){
      copy_from_user( &ti, (void *)arg, sizeof( ti ) );

      if( ti.cdti_trk0 < sjcd_first_track_no ) return( -EINVAL );
      if( ti.cdti_trk1 > sjcd_last_track_no )
	ti.cdti_trk1 = sjcd_last_track_no;
      if( ti.cdti_trk0 > ti.cdti_trk1 ) return( -EINVAL );

      sjcd_playing.start = sjcd_table_of_contents[ ti.cdti_trk0 ].un.track_msf;
      sjcd_playing.end = ( ti.cdti_trk1 < sjcd_last_track_no ) ?
	sjcd_table_of_contents[ ti.cdti_trk1 + 1 ].un.track_msf :
	  sjcd_table_of_contents[ 0 ].un.track_msf;
      
      if( sjcd_play( &sjcd_playing ) < 0 ){
	sjcd_audio_status = CDROM_AUDIO_ERROR;
	return( -EIO );
      } else sjcd_audio_status = CDROM_AUDIO_PLAY;
    }
    return( s );
  }

  case CDROMPLAYMSF:{
    struct cdrom_msf sjcd_msf; int s;
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: playmsf\n" );
#endif
    if( ( s = verify_area( VERIFY_READ, (void *)arg, sizeof( sjcd_msf ) ) ) == 0 ){
      if( sjcd_audio_status == CDROM_AUDIO_PLAY ){
	sjcd_send_cmd( SCMD_PAUSE );
	( void )sjcd_receive_status();
	sjcd_audio_status = CDROM_AUDIO_NO_STATUS;
      }

      copy_from_user( &sjcd_msf, (void *)arg, sizeof( sjcd_msf ) );

      sjcd_playing.start.min = bin2bcd( sjcd_msf.cdmsf_min0 );
      sjcd_playing.start.sec = bin2bcd( sjcd_msf.cdmsf_sec0 );
      sjcd_playing.start.frame = bin2bcd( sjcd_msf.cdmsf_frame0 );
      sjcd_playing.end.min = bin2bcd( sjcd_msf.cdmsf_min1 );
      sjcd_playing.end.sec = bin2bcd( sjcd_msf.cdmsf_sec1 );
      sjcd_playing.end.frame = bin2bcd( sjcd_msf.cdmsf_frame1 );

      if( sjcd_play( &sjcd_playing ) < 0 ){
	sjcd_audio_status = CDROM_AUDIO_ERROR;
	return( -EIO );
      } else sjcd_audio_status = CDROM_AUDIO_PLAY;
    }
    return( s );
  }

  case CDROMREADTOCHDR:{
    struct cdrom_tochdr toc_header; int s;
#if defined (SJCD_TRACE )
    printk( "SJCD: ioctl: readtocheader\n" );
#endif
    if( ( s = verify_area( VERIFY_WRITE, (void *)arg, sizeof( toc_header ) ) ) == 0 ){
      toc_header.cdth_trk0 = sjcd_first_track_no;
      toc_header.cdth_trk1 = sjcd_last_track_no;
      copy_to_user( (void *)arg, &toc_header, sizeof( toc_header ) );
    }
    return( s );
  }

  case CDROMREADTOCENTRY:{
    struct cdrom_tocentry toc_entry; int s;
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: readtocentry\n" );
#endif
    if( ( s = verify_area( VERIFY_WRITE, (void *)arg, sizeof( toc_entry ) ) ) == 0 ){
      struct sjcd_hw_disk_info *tp;

      copy_from_user( &toc_entry, (void *)arg, sizeof( toc_entry ) );

      if( toc_entry.cdte_track == CDROM_LEADOUT )
	tp = &sjcd_table_of_contents[ 0 ];
      else if( toc_entry.cdte_track < sjcd_first_track_no ) return( -EINVAL );
      else if( toc_entry.cdte_track > sjcd_last_track_no ) return( -EINVAL );
      else tp = &sjcd_table_of_contents[ toc_entry.cdte_track ];

      toc_entry.cdte_adr = tp->track_control & 0x0F;
      toc_entry.cdte_ctrl = tp->track_control >> 4;

      switch( toc_entry.cdte_format ){
      case CDROM_LBA:
	toc_entry.cdte_addr.lba = msf2hsg( &( tp->un.track_msf ) );
	break;
      case CDROM_MSF:
	toc_entry.cdte_addr.msf.minute = bcd2bin( tp->un.track_msf.min );
	toc_entry.cdte_addr.msf.second = bcd2bin( tp->un.track_msf.sec );
	toc_entry.cdte_addr.msf.frame = bcd2bin( tp->un.track_msf.frame );
	break;
      default: return( -EINVAL );
      }
      copy_to_user( (void *)arg, &toc_entry, sizeof( toc_entry ) );
    }
    return( s );
  }

  case CDROMSUBCHNL:{
    struct cdrom_subchnl subchnl; int s;
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: subchnl\n" );
#endif
    if( ( s = verify_area( VERIFY_WRITE, (void *)arg, sizeof( subchnl ) ) ) == 0 ){
      struct sjcd_hw_qinfo q_info;

      copy_from_user( &subchnl, (void *)arg, sizeof( subchnl ) );
      if( sjcd_get_q_info( &q_info ) < 0 ) return( -EIO );

      subchnl.cdsc_audiostatus = sjcd_audio_status;
      subchnl.cdsc_adr = q_info.track_control & 0x0F;
      subchnl.cdsc_ctrl = q_info.track_control >> 4;
      subchnl.cdsc_trk = bcd2bin( q_info.track_no );
      subchnl.cdsc_ind = bcd2bin( q_info.x );

      switch( subchnl.cdsc_format ){
      case CDROM_LBA:
	subchnl.cdsc_absaddr.lba = msf2hsg( &( q_info.abs ) );
	subchnl.cdsc_reladdr.lba = msf2hsg( &( q_info.rel ) );
	break;
      case CDROM_MSF:
	subchnl.cdsc_absaddr.msf.minute = bcd2bin( q_info.abs.min );
	subchnl.cdsc_absaddr.msf.second = bcd2bin( q_info.abs.sec );
	subchnl.cdsc_absaddr.msf.frame = bcd2bin( q_info.abs.frame );
	subchnl.cdsc_reladdr.msf.minute = bcd2bin( q_info.rel.min );
	subchnl.cdsc_reladdr.msf.second = bcd2bin( q_info.rel.sec );
	subchnl.cdsc_reladdr.msf.frame = bcd2bin( q_info.rel.frame );
	break;
      default: return( -EINVAL );
      }
      copy_to_user( (void *)arg, &subchnl, sizeof( subchnl ) );
    }
    return( s );
  }

  case CDROMVOLCTRL:{
    struct cdrom_volctrl vol_ctrl; int s;
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: volctrl\n" );
#endif
    if( ( s = verify_area( VERIFY_READ, (void *)arg, sizeof( vol_ctrl ) ) ) == 0 ){
      unsigned char dummy[ 4 ];

      copy_from_user( &vol_ctrl, (void *)arg, sizeof( vol_ctrl ) );
      sjcd_send_4_cmd( SCMD_SET_VOLUME, vol_ctrl.channel0, 0xFF,
		      vol_ctrl.channel1, 0xFF );
      if( sjcd_receive_status() < 0 ) return( -EIO );
      ( void )sjcd_load_response( dummy, 4 );
    }
    return( s );
  }

  case CDROMEJECT:{
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: eject\n" );
#endif
    if( !sjcd_command_is_in_progress ){
      sjcd_tray_unlock();
      sjcd_send_cmd( SCMD_EJECT_TRAY );
      ( void )sjcd_receive_status();
    }
    return( 0 );
  }

#if defined( SJCD_GATHER_STAT )
  case 0xABCD:{
    int s;
#if defined( SJCD_TRACE )
    printk( "SJCD: ioctl: statistic\n" );
#endif
    if( ( s = verify_area( VERIFY_WRITE, (void *)arg, sizeof( statistic ) ) ) == 0 )
      copy_to_user( (void *)arg, &statistic, sizeof( statistic ) );
    return( s );
  }
#endif

  default:
    return( -EINVAL );
  }
}

/*
 * Invalidate internal buffers of the driver.
 */
static void sjcd_invalidate_buffers( void ){
  int i;
  for( i = 0; i < SJCD_BUF_SIZ; sjcd_buf_bn[ i++ ] = -1 );
  sjcd_buf_out = -1;
}

/*
 * Take care of the different block sizes between cdrom and Linux.
 * When Linux gets variable block sizes this will probably go away.
 */

#define CURRENT_IS_VALID                                      \
    ( !QUEUE_EMPTY && MAJOR( CURRENT->rq_dev ) == MAJOR_NR && \
      CURRENT->cmd == READ && CURRENT->sector != -1 )

static void sjcd_transfer( void ){
#if defined( SJCD_TRACE )
  printk( "SJCD: transfer:\n" );
#endif
  if( CURRENT_IS_VALID ){
    while( CURRENT->nr_sectors ){
      int i, bn = CURRENT->sector / 4;
      for( i = 0; i < SJCD_BUF_SIZ && sjcd_buf_bn[ i ] != bn; i++ );
      if( i < SJCD_BUF_SIZ ){
	int offs = ( i * 4 + ( CURRENT->sector & 3 ) ) * 512;
	int nr_sectors = 4 - ( CURRENT->sector & 3 );
	if( sjcd_buf_out != i ){
	  sjcd_buf_out = i;
	  if( sjcd_buf_bn[ i ] != bn ){
	    sjcd_buf_out = -1;
	    continue;
	  }
	}
	if( nr_sectors > CURRENT->nr_sectors )
	  nr_sectors = CURRENT->nr_sectors;
#if defined( SJCD_TRACE )
	printk( "SJCD: copy out\n" );
#endif
	memcpy( CURRENT->buffer, sjcd_buf + offs, nr_sectors * 512 );
	CURRENT->nr_sectors -= nr_sectors;
	CURRENT->sector += nr_sectors;
	CURRENT->buffer += nr_sectors * 512;
      } else {
	sjcd_buf_out = -1;
	break;
      }
    }
  }
#if defined( SJCD_TRACE )
  printk( "SJCD: transfer: done\n" );
#endif
}

static void sjcd_poll( void ){
#if defined( SJCD_GATHER_STAT )
  /*
   * Update total number of ticks.
   */
  statistic.ticks++;
  statistic.tticks[ sjcd_transfer_state ]++;
#endif

 ReSwitch: switch( sjcd_transfer_state ){
      
  case SJCD_S_IDLE:{
#if defined( SJCD_GATHER_STAT )
    statistic.idle_ticks++;
#endif
#if defined( SJCD_TRACE )
    printk( "SJCD_S_IDLE\n" );
#endif
    return;
  }

  case SJCD_S_START:{
#if defined( SJCD_GATHER_STAT )
    statistic.start_ticks++;
#endif
    sjcd_send_cmd( SCMD_GET_STATUS );
    sjcd_transfer_state =
      sjcd_mode == SCMD_MODE_COOKED ? SJCD_S_READ : SJCD_S_MODE;
    sjcd_transfer_timeout = 500;
#if defined( SJCD_TRACE )
    printk( "SJCD_S_START: goto SJCD_S_%s mode\n",
	   sjcd_transfer_state == SJCD_S_READ ? "READ" : "MODE" );
#endif
    break;
  }
    
  case SJCD_S_MODE:{
    if( sjcd_check_status() ){
      /*
       * Previous command is completed.
       */
      if( !sjcd_status_valid || sjcd_command_failed ){
#if defined( SJCD_TRACE )
	printk( "SJCD_S_MODE: pre-cmd failed: goto to SJCD_S_STOP mode\n" );
#endif
	sjcd_transfer_state = SJCD_S_STOP;
	goto ReSwitch;
      }

      sjcd_mode = 0; /* unknown mode; should not be valid when failed */
      sjcd_send_1_cmd( SCMD_SET_MODE, SCMD_MODE_COOKED );
      sjcd_transfer_state = SJCD_S_READ; sjcd_transfer_timeout = 1000;
#if defined( SJCD_TRACE )
      printk( "SJCD_S_MODE: goto SJCD_S_READ mode\n" );
#endif
    }
#if defined( SJCD_GATHER_STAT )
    else statistic.mode_ticks++;
#endif
    break;
  }

  case SJCD_S_READ:{
    if( sjcd_status_valid ? 1 : sjcd_check_status() ){
      /*
       * Previous command is completed.
       */
      if( !sjcd_status_valid || sjcd_command_failed ){
#if defined( SJCD_TRACE )
	printk( "SJCD_S_READ: pre-cmd failed: goto to SJCD_S_STOP mode\n" );
#endif
	sjcd_transfer_state = SJCD_S_STOP;
	goto ReSwitch;
      }
      if( !sjcd_media_is_available ){
#if defined( SJCD_TRACE )
	printk( "SJCD_S_READ: no disk: goto to SJCD_S_STOP mode\n" );
#endif
	sjcd_transfer_state = SJCD_S_STOP;
	goto ReSwitch;
      }
      if( sjcd_mode != SCMD_MODE_COOKED ){
	/*
	 * We seem to come from set mode. So discard one byte of result.
	 */
	if( sjcd_load_response( &sjcd_mode, 1 ) != 0 ){
#if defined( SJCD_TRACE )
	  printk( "SJCD_S_READ: load failed: goto to SJCD_S_STOP mode\n" );
#endif
	  sjcd_transfer_state = SJCD_S_STOP;
	  goto ReSwitch;