sjcd.c

讲述linux的初始化过程

/* -- sjcd.c
 *
 *   Sanyo CD-ROM device driver implementation, Version 1.6
 *   Copyright (C) 1995  Vadim V. Model
 *
 *   [e-mail]
 *   [e-mail]
 *   [e-mail]
 *
 *
 *  This driver is based on pre-works by Eberhard Moenkeberg ([e-mail]);
 *  it was developed under use of mcd.c from Martin Harriss, with help of
 *  Eric van der Maarel ([e-mail]).
 *
 *  It is planned to include these routines into sbpcd.c later - to make
 *  a "mixed use" on one cable possible for all kinds of drives which use
 *  the SoundBlaster/Panasonic style CDROM interface. But today, the
 *  ability to install directly from CDROM is more important than flexibility.
 *
 *  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.
 *
 *  History:
 *  1.1 First public release with kernel version 1.3.7.
 *      Written by Vadim Model.
 *  1.2 Added detection and configuration of cdrom interface
 *      on ISP16 soundcard.
 *      Allow for command line options: sjcd=<io_base>,<irq>,<dma>
 *  1.3 Some minor changes to README.sjcd.
 *  1.4 MSS Sound support!! Listen to a CD through the speakers.
 *  1.5 Module support and bugfixes.
 *      Tray locking.
 *  1.6 Removed ISP16 code from this driver.
 *      Allow only to set io base address on command line: sjcd=<io_base>
 *      Changes to Documentation/cdrom/sjcd
 *      Added cleanup after any error in the initialisation.
 *  1.7 Added code to set the sector size tables to prevent the bug present in 
 *      the previous version of this driver.  Coded added by Anthony Barbachan 
 *      from bugfix tip originally suggested by Alan Cox.
 *
 *  November 1999 -- Make kernel-parameter implementation work with 2.3.x 
 *	             Removed init_module & cleanup_module in favor of 
 *	             module_init & module_exit.
 *	             Torben Mathiasen <[e-mail]>
 */

#define SJCD_VERSION_MAJOR 1
#define SJCD_VERSION_MINOR 7

#include <linux/module.h>
#include <linux/errno.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/timer.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/cdrom.h>
#include <linux/ioport.h>
#include <linux/string.h>
#include <linux/major.h>
#include <linux/init.h>
#include <linux/devfs_fs_kernel.h>

#include <asm/system.h>
#include <asm/io.h>
#include <asm/uaccess.h>

#define MAJOR_NR SANYO_CDROM_MAJOR
#include <linux/blk.h>
#include "sjcd.h"

static int sjcd_present = 0;

#define SJCD_BUF_SIZ 32 /* cdr-h94a has internal 64K buffer */

/*
 * buffer for block size conversion
 */
static char sjcd_buf[ 2048 * SJCD_BUF_SIZ ];
static volatile int sjcd_buf_bn[ SJCD_BUF_SIZ ], sjcd_next_bn;
static volatile int sjcd_buf_in, sjcd_buf_out = -1;

/*
 * Status.
 */
static unsigned short sjcd_status_valid = 0;
static unsigned short sjcd_door_closed;
static unsigned short sjcd_door_was_open;
static unsigned short sjcd_media_is_available;
static unsigned short sjcd_media_is_changed;
static unsigned short sjcd_toc_uptodate = 0;
static unsigned short sjcd_command_failed;
static volatile unsigned char sjcd_completion_status = 0;
static volatile unsigned char sjcd_completion_error = 0;
static unsigned short sjcd_command_is_in_progress = 0;
static unsigned short sjcd_error_reported = 0;

static int sjcd_open_count;

static int sjcd_audio_status;
static struct sjcd_play_msf sjcd_playing;

static int sjcd_base = SJCD_BASE_ADDR;

#ifdef MODULE
MODULE_PARM(sjcd_base, "i");
#endif

static DECLARE_WAIT_QUEUE_HEAD(sjcd_waitq);

/*
 * Data transfer.
 */
static volatile unsigned short sjcd_transfer_is_active = 0;

enum sjcd_transfer_state {
  SJCD_S_IDLE     = 0,
  SJCD_S_START    = 1,
  SJCD_S_MODE     = 2,
  SJCD_S_READ     = 3,
  SJCD_S_DATA     = 4,
  SJCD_S_STOP     = 5,
  SJCD_S_STOPPING = 6
};
static enum sjcd_transfer_state sjcd_transfer_state = SJCD_S_IDLE;
static long sjcd_transfer_timeout = 0;
static int sjcd_read_count = 0;
static unsigned char sjcd_mode = 0;

#define SJCD_READ_TIMEOUT 5000

#if defined( SJCD_GATHER_STAT )
/*
 * Statistic.
 */
static struct sjcd_stat statistic;
#endif

/*
 * Timer.
 */
static struct timer_list sjcd_delay_timer;

#define SJCD_SET_TIMER( func, tmout )           \
    ( sjcd_delay_timer.expires = jiffies+tmout,         \
      sjcd_delay_timer.function = ( void * )func, \
      add_timer( &sjcd_delay_timer ) )

#define CLEAR_TIMER del_timer( &sjcd_delay_timer )

static int sjcd_cleanup(void);

/*
 * Set up device, i.e., use command line data to set
 * base address.
 */
#ifndef MODULE
static int __init sjcd_setup( char *str)
{
   int ints[2];
   (void)get_options(str, ARRAY_SIZE(ints), ints);
   if (ints[0] > 0)
      sjcd_base = ints[1];

   return 1;
}

__setup("sjcd=", sjcd_setup);

#endif

/*
 * Special converters.
 */
static unsigned char bin2bcd( int bin ){
  int u, v;

  u = bin % 10; v = bin / 10;
  return( u | ( v << 4 ) );
}

static int bcd2bin( unsigned char bcd ){
    return( ( bcd >> 4 ) * 10 + ( bcd & 0x0F ) );
}

static long msf2hsg( struct msf *mp ){
  return( bcd2bin( mp->frame ) + bcd2bin( mp->sec ) * 75
	 + bcd2bin( mp->min ) * 4500 - 150 );
}

static void hsg2msf( long hsg, struct msf *msf ){
  hsg += 150; msf->min = hsg / 4500;
  hsg %= 4500; msf->sec = hsg / 75; msf->frame = hsg % 75;
  msf->min = bin2bcd( msf->min );       /* convert to BCD */
  msf->sec = bin2bcd( msf->sec );
  msf->frame = bin2bcd( msf->frame );
}

/*
 * Send a command to cdrom. Invalidate status.
 */
static void sjcd_send_cmd( unsigned char cmd ){
#if defined( SJCD_TRACE )
  printk( "SJCD: send_cmd( 0x%x )\n", cmd );
#endif
  outb( cmd, SJCDPORT( 0 ) );
  sjcd_command_is_in_progress = 1;
  sjcd_status_valid = 0;
  sjcd_command_failed = 0;
}

/*
 * Send a command with one arg to cdrom. Invalidate status.
 */
static void sjcd_send_1_cmd( unsigned char cmd, unsigned char a ){
#if defined( SJCD_TRACE )
  printk( "SJCD: send_1_cmd( 0x%x, 0x%x )\n", cmd, a );
#endif
  outb( cmd, SJCDPORT( 0 ) );
  outb( a, SJCDPORT( 0 ) );
  sjcd_command_is_in_progress = 1;
  sjcd_status_valid = 0;
  sjcd_command_failed = 0;
}

/*
 * Send a command with four args to cdrom. Invalidate status.
 */
static void sjcd_send_4_cmd( unsigned char cmd, unsigned char a,
	    unsigned char b, unsigned char c, unsigned char d ){
#if defined( SJCD_TRACE )
  printk( "SJCD: send_4_cmd( 0x%x )\n", cmd );
#endif
  outb( cmd, SJCDPORT( 0 ) );
  outb( a, SJCDPORT( 0 ) );
  outb( b, SJCDPORT( 0 ) );
  outb( c, SJCDPORT( 0 ) );
  outb( d, SJCDPORT( 0 ) );
  sjcd_command_is_in_progress = 1;
  sjcd_status_valid = 0;
  sjcd_command_failed = 0;
}

/*
 * Send a play or read command to cdrom. Invalidate Status.
 */
static void sjcd_send_6_cmd( unsigned char cmd, struct sjcd_play_msf *pms ){
#if defined( SJCD_TRACE )
  printk( "SJCD: send_long_cmd( 0x%x )\n", cmd );
#endif
  outb( cmd, SJCDPORT( 0 ) );
  outb( pms->start.min,   SJCDPORT( 0 ) );
  outb( pms->start.sec,   SJCDPORT( 0 ) );
  outb( pms->start.frame, SJCDPORT( 0 ) );
  outb( pms->end.min,     SJCDPORT( 0 ) );
  outb( pms->end.sec,     SJCDPORT( 0 ) );
  outb( pms->end.frame,   SJCDPORT( 0 ) );
  sjcd_command_is_in_progress = 1;
  sjcd_status_valid = 0;
  sjcd_command_failed = 0;
}

/*
 * Get a value from the data port. Should not block, so we use a little
 * wait for a while. Returns 0 if OK.
 */
static int sjcd_load_response( void *buf, int len ){
  unsigned char *resp = ( unsigned char * )buf;

  for( ; len; --len ){ 
    int i;
    for( i = 200; i-- && !SJCD_STATUS_AVAILABLE( inb( SJCDPORT( 1 ) ) ); );
    if( i > 0 ) *resp++ = ( unsigned char )inb( SJCDPORT( 0 ) );
    else break;
  }
  return( len );
}

/*
 * Load and parse command completion status (drive info byte and maybe error).
 * Sorry, no error classification yet.
 */
static void sjcd_load_status( void ){
  sjcd_media_is_changed = 0;
  sjcd_completion_error = 0;
  sjcd_completion_status = inb( SJCDPORT( 0 ) );
  if( sjcd_completion_status & SST_DOOR_OPENED ){
    sjcd_door_closed = sjcd_media_is_available = 0;
  } else {
    sjcd_door_closed = 1;
    if( sjcd_completion_status & SST_MEDIA_CHANGED )
      sjcd_media_is_available = sjcd_media_is_changed = 1;
    else if( sjcd_completion_status & 0x0F ){
      /*
       * OK, we seem to catch an error ...
       */
      while( !SJCD_STATUS_AVAILABLE( inb( SJCDPORT( 1 ) ) ) );
      sjcd_completion_error = inb( SJCDPORT( 0 ) );
      if( ( sjcd_completion_status & 0x08 ) &&
	 ( sjcd_completion_error & 0x40 ) )
	sjcd_media_is_available = 0;
      else sjcd_command_failed = 1;
    } else sjcd_media_is_available = 1;
  }
  /*
   * Ok, status loaded successfully.
   */
  sjcd_status_valid = 1, sjcd_error_reported = 0;
  sjcd_command_is_in_progress = 0;

  /*
   * If the disk is changed, the TOC is not valid.
   */
  if( sjcd_media_is_changed ) sjcd_toc_uptodate = 0;
#if defined( SJCD_TRACE )
  printk( "SJCD: status %02x.%02x loaded.\n",
	 ( int )sjcd_completion_status, ( int )sjcd_completion_error );
#endif
}

/*
 * Read status from cdrom. Check to see if the status is available.
 */
static int sjcd_check_status( void ){
  /*
   * Try to load the response from cdrom into buffer.
   */
  if( SJCD_STATUS_AVAILABLE( inb( SJCDPORT( 1 ) ) ) ){
    sjcd_load_status();
    return( 1 );
  } else {
    /*
     * No status is available.
     */
    return( 0 );
  }
}

/*
 * This is just timeout counter, and nothing more. Surprised ? :-)
 */
static volatile long sjcd_status_timeout;

/*
 * We need about 10 seconds to wait. The longest command takes about 5 seconds
 * to probe the disk (usually after tray closed or drive reset). Other values
 * should be thought of for other commands.
 */
#define SJCD_WAIT_FOR_STATUS_TIMEOUT 1000

static void sjcd_status_timer( void ){
  if( sjcd_check_status() ){
    /*
     * The command completed and status is loaded, stop waiting.
     */
    wake_up( &sjcd_waitq );
  } else if( --sjcd_status_timeout <= 0 ){
    /*
     * We are timed out. 
     */
    wake_up( &sjcd_waitq );
  } else {
    /*
     * We have still some time to wait. Try again.
     */
    SJCD_SET_TIMER( sjcd_status_timer, 1 );
  }
}

/*
 * Wait for status for 10 sec approx. Returns non-positive when timed out.
 * Should not be used while reading data CDs.
 */
static int sjcd_wait_for_status( void ){
  sjcd_status_timeout = SJCD_WAIT_FOR_STATUS_TIMEOUT;
  SJCD_SET_TIMER( sjcd_status_timer, 1 ); 
  sleep_on( &sjcd_waitq );    
#if defined( SJCD_DIAGNOSTIC ) || defined ( SJCD_TRACE )
  if( sjcd_status_timeout <= 0 )
    printk( "SJCD: Error Wait For Status.\n" );
#endif
  return( sjcd_status_timeout );
}

static int sjcd_receive_status( void ){
  int i;
#if defined( SJCD_TRACE )
  printk( "SJCD: receive_status\n" );
#endif
  /*
   * Wait a bit for status available.
   */
  for( i = 200; i-- && ( sjcd_check_status() == 0 ); );
  if( i < 0 ){
#if defined( SJCD_TRACE )
    printk( "SJCD: long wait for status\n" );
#endif
    if( sjcd_wait_for_status() <= 0 )
      printk( "SJCD: Timeout when read status.\n" );
    else i = 0;
  }
  return( i );
}

/*
 * Load the status. Issue get status command and wait for status available.
 */
static void sjcd_get_status( void ){
#if defined( SJCD_TRACE )
  printk( "SJCD: get_status\n" );
#endif
  sjcd_send_cmd( SCMD_GET_STATUS );
  sjcd_receive_status();
}

/*
 * Check the drive if the disk is changed. Should be revised.
 */
static int sjcd_disk_change( kdev_t full_dev ){
#if 0
  printk( "SJCD: sjcd_disk_change( 0x%x )\n", full_dev );
#endif
  if( MINOR( full_dev ) > 0 ){
    printk( "SJCD: request error: invalid device minor.\n" );
    return 0;
  }
  if( !sjcd_command_is_in_progress )
    sjcd_get_status();
  return( sjcd_status_valid ? sjcd_media_is_changed : 0 );
}

/*
 * Read the table of contents (TOC) and TOC header if necessary.
 * We assume that the drive contains no more than 99 toc entries.
 */
static struct sjcd_hw_disk_info sjcd_table_of_contents[ SJCD_MAX_TRACKS ];
static unsigned char sjcd_first_track_no, sjcd_last_track_no;
#define sjcd_disk_length  sjcd_table_of_contents[0].un.track_msf

static int sjcd_update_toc( void ){
  struct sjcd_hw_disk_info info;
  int i;
#if defined( SJCD_TRACE )
  printk( "SJCD: update toc:\n" );
#endif
  /*
   * check to see if we need to do anything
   */
  if( sjcd_toc_uptodate ) return( 0 );

  /*
   * Get the TOC start information.
   */
  sjcd_send_1_cmd( SCMD_GET_DISK_INFO, SCMD_GET_1_TRACK );
  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 TOC start.\n" );
      return( -1 );
    }
    sjcd_first_track_no = bcd2bin( info.un.track_no );
  } else {
    printk( "SJCD: get first failed\n" );
    return( -1 );
  }
#if defined( SJCD_TRACE )
  printk( "SJCD: TOC start 0x%02x ", sjcd_first_track_no );
#endif
  /*
   * Get the TOC finish information.
   */
  sjcd_send_1_cmd( SCMD_GET_DISK_INFO, SCMD_GET_L_TRACK );
  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 TOC finish.\n" );
      return( -1 );
    }
    sjcd_last_track_no = bcd2bin( info.un.track_no );
  } else {
    printk( "SJCD: get last failed\n" );
    return( -1 );
  }
#if defined( SJCD_TRACE )
  printk( "SJCD: TOC finish 0x%02x ", sjcd_last_track_no );
#endif
  for( i = sjcd_first_track_no; i <= sjcd_last_track_no; i++ ){
    /*
     * Get the first track information.
     */
    sjcd_send_1_cmd( SCMD_GET_DISK_INFO, bin2bcd( i ) );
    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 );
    }