cdu31a.c

powerpc内核 mpc8241芯片 linux系统下cdrom驱动程序

         *result_buffer = read_result_register();
         result_buffer++;
         (*result_size)++;
         b--;
      }
   }
}

/*
 * Do a command that does not involve data transfer.  This routine must
 * be re-entrant from the same task to support being called from the
 * data operation code when an error occurs.
 */
static void
do_sony_cd_cmd(unsigned char cmd,
               unsigned char *params,
               unsigned int num_params,
               unsigned char *result_buffer,
               unsigned int *result_size)
{
   unsigned int retry_count;
   int num_retries;
   int recursive_call;
   unsigned long flags;


   save_flags(flags);
   cli();
   if (current != has_cd_task) /* Allow recursive calls to this routine */
   {
      while (sony_inuse)
      {
         interruptible_sleep_on(&sony_wait);
         if (signal_pending(current))
         {
            result_buffer[0] = 0x20;
            result_buffer[1] = SONY_SIGNAL_OP_ERR;
            *result_size = 2;
            restore_flags(flags);
            return;
         }
      }
      sony_inuse = 1;
      has_cd_task = current;
      recursive_call = 0;
   }
   else
   {
      recursive_call = 1;
   }

   num_retries = 0;
retry_cd_operation:

   while (handle_sony_cd_attention())
      ;

   sti();
   
   retry_count = jiffies + SONY_JIFFIES_TIMEOUT;
   while (time_before(jiffies, retry_count) && (is_busy()))
   {
      sony_sleep();
      
      while (handle_sony_cd_attention())
         ;
   }
   if (is_busy())
   {
#if DEBUG
      printk("CDU31A timeout out %d\n", __LINE__);
#endif
      result_buffer[0] = 0x20;
      result_buffer[1] = SONY_TIMEOUT_OP_ERR;
      *result_size = 2;
   }
   else
   {
      clear_result_ready();
      clear_param_reg();

      write_params(params, num_params);
      write_cmd(cmd);

      get_result(result_buffer, result_size);
   }

   if (   ((result_buffer[0] & 0xf0) == 0x20)
       && (num_retries < MAX_CDU31A_RETRIES))
   {
      num_retries++;
      current->state = TASK_INTERRUPTIBLE;
      schedule_timeout(HZ/10);  /* Wait .1 seconds on retries */
      goto retry_cd_operation;
   }

   if (!recursive_call)
   {
      has_cd_task = NULL;
      sony_inuse = 0;
      wake_up_interruptible(&sony_wait);
   }

   restore_flags(flags);
}


/*
 * Handle an attention from the drive.  This will return 1 if it found one
 * or 0 if not (if one is found, the caller might want to call again).
 *
 * This routine counts the number of consecutive times it is called
 * (since this is always called from a while loop until it returns
 * a 0), and returns a 0 if it happens too many times.  This will help
 * prevent a lockup.
 */
static int
handle_sony_cd_attention(void)
{
   unsigned char atten_code;
   static int num_consecutive_attentions = 0;
   volatile int val;


#if 0*DEBUG
   printk("Entering handle_sony_cd_attention\n");
#endif
   if (is_attention())
   {
      if (num_consecutive_attentions > CDU31A_MAX_CONSECUTIVE_ATTENTIONS)
      {
         printk("cdu31a: Too many consecutive attentions: %d\n",
                num_consecutive_attentions);
         num_consecutive_attentions = 0;
#if DEBUG
         printk("Leaving handle_sony_cd_attention at %d\n", __LINE__);
#endif
         return(0);
      }

      clear_attention();
      atten_code = read_result_register();

      switch (atten_code)
      {
       /* Someone changed the CD.  Mark it as changed */
      case SONY_MECH_LOADED_ATTN:
         disk_changed = 1;
	 sony_toc_read = 0;
         sony_audio_status = CDROM_AUDIO_NO_STATUS;
         sony_blocks_left = 0;
         break;

      case SONY_SPIN_DOWN_COMPLETE_ATTN:
         /* Mark the disk as spun down. */
         sony_spun_up = 0;
         break;

      case SONY_AUDIO_PLAY_DONE_ATTN:
         sony_audio_status = CDROM_AUDIO_COMPLETED;
         read_subcode();
         break;

      case SONY_EJECT_PUSHED_ATTN:
         if (is_auto_eject)
         {
            sony_audio_status = CDROM_AUDIO_INVALID;
         }
         break;

      case SONY_LEAD_IN_ERR_ATTN:
      case SONY_LEAD_OUT_ERR_ATTN:
      case SONY_DATA_TRACK_ERR_ATTN:
      case SONY_AUDIO_PLAYBACK_ERR_ATTN:
         sony_audio_status = CDROM_AUDIO_ERROR;
         break;
      }

      num_consecutive_attentions++;
#if DEBUG
      printk("Leaving handle_sony_cd_attention at %d\n", __LINE__);
#endif
      return(1);
   }
   else if (abort_read_started)
   {
      while (is_result_reg_not_empty())
      {
         val = read_result_register();
      }
      clear_data_ready();
      clear_result_ready();
      /* Clear out the data */
      while (is_data_requested())
      {
         val = read_data_register();
      }
      abort_read_started = 0;
#if DEBUG
      printk("Leaving handle_sony_cd_attention at %d\n", __LINE__);
#endif
      return(1);
   }

   num_consecutive_attentions = 0;
#if 0*DEBUG
   printk("Leaving handle_sony_cd_attention at %d\n", __LINE__);
#endif
   return(0);
}


/* Convert from an integer 0-99 to BCD */
static inline unsigned int
int_to_bcd(unsigned int val)
{
   int retval;


   retval = (val / 10) << 4;
   retval = retval | val % 10;
   return(retval);
}


/* Convert from BCD to an integer from 0-99 */
static unsigned int
bcd_to_int(unsigned int bcd)
{
   return((((bcd >> 4) & 0x0f) * 10) + (bcd & 0x0f));
}


/*
 * Convert a logical sector value (like the OS would want to use for
 * a block device) to an MSF format.
 */
static void
log_to_msf(unsigned int log, unsigned char *msf)
{
   log = log + LOG_START_OFFSET;
   msf[0] = int_to_bcd(log / 4500);
   log = log % 4500;
   msf[1] = int_to_bcd(log / 75);
   msf[2] = int_to_bcd(log % 75);
}


/*
 * Convert an MSF format to a logical sector.
 */
static unsigned int
msf_to_log(unsigned char *msf)
{
   unsigned int log;


   log = msf[2];
   log += msf[1] * 75;
   log += msf[0] * 4500;
   log = log - LOG_START_OFFSET;

   return log;
}


/*
 * Take in integer size value and put it into a buffer like
 * the drive would want to see a number-of-sector value.
 */
static void
size_to_buf(unsigned int size,
            unsigned char *buf)
{
   buf[0] = size / 65536;
   size = size % 65536;
   buf[1] = size / 256;
   buf[2] = size % 256;
}

/* Starts a read operation. Returns 0 on success and 1 on failure. 
   The read operation used here allows multiple sequential sectors 
   to be read and status returned for each sector.  The driver will
   read the output one at a time as the requests come and abort the
   operation if the requested sector is not the next one from the
   drive. */
static int
start_request(unsigned int sector,
              unsigned int nsect,
              int          read_nsect_only)
{
   unsigned char params[6];
   unsigned int read_size;
   unsigned int retry_count;


#if DEBUG
   printk("Entering start_request\n");
#endif
   log_to_msf(sector, params);
   /* If requested, read exactly what was asked. */
   if (read_nsect_only)
   {
      read_size = nsect;
   }
   /*
    * If the full read-ahead would go beyond the end of the media, trim
    * it back to read just till the end of the media.
    */
   else if ((sector + nsect) >= sony_toc.lead_out_start_lba)
   {
      read_size = sony_toc.lead_out_start_lba - sector;
   }
   /* Read the full readahead amount. */
   else
   {
      read_size = CDU31A_READAHEAD / 4;
   }
   size_to_buf(read_size, &params[3]);

   /*
    * Clear any outstanding attentions and wait for the drive to
    * complete any pending operations.
    */
   while (handle_sony_cd_attention())
      ;

   retry_count = jiffies + SONY_JIFFIES_TIMEOUT;
   while (time_before(jiffies, retry_count) && (is_busy()))
   {
      sony_sleep();
      
      while (handle_sony_cd_attention())
         ;
   }

   if (is_busy())
   {
      printk("CDU31A: Timeout while waiting to issue command\n");
#if DEBUG
      printk("Leaving start_request at %d\n", __LINE__);
#endif
      return(1);
   }
   else
   {
      /* Issue the command */
      clear_result_ready();
      clear_param_reg();

      write_params(params, 6);
      write_cmd(SONY_READ_BLKERR_STAT_CMD);

      sony_blocks_left = read_size * 4;
      sony_next_block = sector * 4;
      readahead_dataleft = 0;
      readahead_bad = 0;
#if DEBUG
      printk("Leaving start_request at %d\n", __LINE__);
#endif
      return(0);
   }
#if DEBUG
   printk("Leaving start_request at %d\n", __LINE__);
#endif
}

/* Abort a pending read operation.  Clear all the drive status and
   readahead variables. */
static void
abort_read(void)
{
   unsigned char result_reg[2];
   int           result_size;
   volatile int  val;


   do_sony_cd_cmd(SONY_ABORT_CMD, NULL, 0, result_reg, &result_size);
   if ((result_reg[0] & 0xf0) == 0x20)
   {
      printk("CDU31A: Error aborting read, %s error\n",
             translate_error(
             result_reg[1]));
   }

   while (is_result_reg_not_empty())
   {
      val = read_result_register();
   }
   clear_data_ready();
   clear_result_ready();
   /* Clear out the data */
   while (is_data_requested())
   {
      val = read_data_register();
   }

   sony_blocks_left = 0;
   readahead_dataleft = 0;
   readahead_bad = 0;
}

/* Called when the timer times out.  This will abort the
   pending read operation. */
static void
handle_abort_timeout(unsigned long data)
{
   unsigned long flags;

#if DEBUG
   printk("Entering handle_abort_timeout\n");
#endif
   save_flags(flags);
   cli();
   /* If it is in use, ignore it. */
   if (!sony_inuse)
   {
      /* We can't use abort_read(), because it will sleep
         or schedule in the timer interrupt.  Just start
         the operation, finish it on the next access to
         the drive. */
      clear_result_ready();
      clear_param_reg();
      write_cmd(SONY_ABORT_CMD);

      sony_blocks_left = 0;
      readahead_dataleft = 0;
      readahead_bad = 0;
      abort_read_started = 1;
   }
   restore_flags(flags);
#if DEBUG
   printk("Leaving handle_abort_timeout\n");
#endif
}

/* Actually get data and status from the drive. */
static void
input_data(char         *buffer,
           unsigned int bytesleft,
           unsigned int nblocks,
           unsigned int offset,
           unsigned int skip)
{
   int i;
   volatile unsigned char val;


#if DEBUG
   printk("Entering input_data\n");
#endif
   /* If an XA disk on a CDU31A, skip the first 12 bytes of data from
      the disk.  The real data is after that. */
   if (sony_xa_mode)
   {
      for(i=0; i<CD_XA_HEAD; i++)
      {
         val = read_data_register();
      }
   }