cdu31a.c

powerpc内核 mpc8241芯片 linux系统下cdrom驱动程序

   clear_data_ready();

   if (bytesleft == 2048) /* 2048 byte direct buffer transfer */
   {
      insb(sony_cd_read_reg, buffer, 2048);
      readahead_dataleft = 0;
   }
   else
   {
      /* If the input read did not align with the beginning of the block,
	 skip the necessary bytes. */
      if (skip != 0)
      {
         insb(sony_cd_read_reg, readahead_buffer, skip);
      }

      /* Get the data into the buffer. */
      insb(sony_cd_read_reg, &buffer[offset], bytesleft);

      /* Get the rest of the data into the readahead buffer at the
	 proper location. */
      readahead_dataleft = (2048 - skip) - bytesleft;
      insb(sony_cd_read_reg,
           readahead_buffer + bytesleft,
           readahead_dataleft);
   }
   sony_blocks_left -= nblocks;
   sony_next_block += nblocks; 

   /* If an XA disk, we have to clear out the rest of the unused
      error correction data. */
   if (sony_xa_mode)
   {
      for(i=0; i<CD_XA_TAIL; i++)
      {
         val = read_data_register();
      }
   }
#if DEBUG
   printk("Leaving input_data at %d\n", __LINE__);
#endif
}

/* read data from the drive.  Note the nsect must be <= 4. */
static void
read_data_block(char          *buffer,
                unsigned int  block,
                unsigned int  nblocks,
                unsigned char res_reg[],
                int           *res_size)
{
   unsigned int retry_count;
   unsigned int bytesleft;
   unsigned int offset;
   unsigned int skip;


#if DEBUG
   printk("Entering read_data_block\n");
#endif

   res_reg[0] = 0;
   res_reg[1] = 0;
   *res_size = 0;
   bytesleft = nblocks * 512;
   offset = 0;

   /* If the data in the read-ahead does not match the block offset,
      then fix things up. */
   if (((block % 4) * 512) != ((2048 - readahead_dataleft) % 2048))
   {
      sony_next_block += block % 4;
      sony_blocks_left -= block % 4;
      skip = (block % 4) * 512;
   }
   else
   {
      skip = 0;
   }

   /* We have readahead data in the buffer, get that first before we
      decide if a read is necessary. */
   if (readahead_dataleft != 0)
   {
      if (bytesleft > readahead_dataleft)
      {
	 /* The readahead will not fill the requested buffer, but
	    get the data out of the readahead into the buffer. */
         memcpy(buffer,
                readahead_buffer + (2048 - readahead_dataleft),
                readahead_dataleft);
         readahead_dataleft = 0;
         bytesleft -= readahead_dataleft;
         offset += readahead_dataleft;
      }
      else
      {
	 /* The readahead will fill the whole buffer, get the data
	    and return. */
         memcpy(buffer,
                readahead_buffer + (2048 - readahead_dataleft),
                bytesleft);
         readahead_dataleft -= bytesleft;
         bytesleft = 0;
         sony_blocks_left -= nblocks;
         sony_next_block += nblocks;

	 /* If the data in the readahead is bad, return an error so the
	    driver will abort the buffer. */
         if (readahead_bad)
         {
            res_reg[0] = 0x20;
            res_reg[1] = SONY_BAD_DATA_ERR;
            *res_size = 2;
         }

         if (readahead_dataleft == 0)
         {
            readahead_bad = 0;
         }

         /* Final transfer is done for read command, get final result. */
         if (sony_blocks_left == 0)
         {
            get_result(res_reg, res_size);
         }
#if DEBUG
         printk("Leaving read_data_block at %d\n", __LINE__);
#endif
         return;
      }
   }

   /* Wait for the drive to tell us we have something */
   retry_count = jiffies + SONY_JIFFIES_TIMEOUT;
   while (time_before(jiffies, retry_count) && !(is_data_ready()))
   {
      while (handle_sony_cd_attention())
         ;

      sony_sleep();
   }
   if (!(is_data_ready()))
   {
      if (is_result_ready())
      {
         get_result(res_reg, res_size);
         if ((res_reg[0] & 0xf0) != 0x20)
         {
            printk("CDU31A: Got result that should have been error: %d\n",
                   res_reg[0]);
            res_reg[0] = 0x20;
            res_reg[1] = SONY_BAD_DATA_ERR;
            *res_size = 2;
         }
         abort_read();
      }
      else
      {
#if DEBUG
         printk("CDU31A timeout out %d\n", __LINE__);
#endif
         res_reg[0] = 0x20;
         res_reg[1] = SONY_TIMEOUT_OP_ERR;
         *res_size = 2;
         abort_read();
      }
   }
   else
   {
      input_data(buffer, bytesleft, nblocks, offset, skip);

      /* Wait for the status from the drive. */
      retry_count = jiffies + SONY_JIFFIES_TIMEOUT;
      while (time_before(jiffies, retry_count) && !(is_result_ready()))
      {
         while (handle_sony_cd_attention())
            ;

         sony_sleep();
      }

      if (!is_result_ready())
      {
#if DEBUG
         printk("CDU31A timeout out %d\n", __LINE__);
#endif
         res_reg[0] = 0x20;
         res_reg[1] = SONY_TIMEOUT_OP_ERR;
         *res_size = 2;
         abort_read();
      }
      else
      {
         get_result(res_reg, res_size);

	 /* If we got a buffer status, handle that. */
         if ((res_reg[0] & 0xf0) == 0x50)
         {

            if (   (res_reg[0] == SONY_NO_CIRC_ERR_BLK_STAT)
                || (res_reg[0] == SONY_NO_LECC_ERR_BLK_STAT)
                || (res_reg[0] == SONY_RECOV_LECC_ERR_BLK_STAT))
            {
	       /* The data was successful, but if data was read from
		  the readahead  and it was bad, set the whole
		  buffer as bad. */
               if (readahead_bad)
               {
                  readahead_bad = 0;
                  res_reg[0] = 0x20;
                  res_reg[1] = SONY_BAD_DATA_ERR;
                  *res_size = 2;
               }
            }
            else
            {
               printk("CDU31A: Data block error: 0x%x\n", res_reg[0]);
               res_reg[0] = 0x20;
               res_reg[1] = SONY_BAD_DATA_ERR;
               *res_size = 2;

               /* Data is in the readahead buffer but an error was returned.
                  Make sure future requests don't use the data. */
               if (bytesleft != 2048)
               {
                  readahead_bad = 1;
               }
            }

            /* Final transfer is done for read command, get final result. */
            if (sony_blocks_left == 0)
            {
               get_result(res_reg, res_size);
            }
         }
         else if ((res_reg[0] & 0xf0) != 0x20)
         {
            /* The drive gave me bad status, I don't know what to do.
               Reset the driver and return an error. */
            printk("CDU31A: Invalid block status: 0x%x\n", res_reg[0]);
            restart_on_error();
            res_reg[0] = 0x20;
            res_reg[1] = SONY_BAD_DATA_ERR;
            *res_size = 2;
         }
      }
   }
#if DEBUG
   printk("Leaving read_data_block at %d\n", __LINE__);
#endif
}


/*
 * The OS calls this to perform a read or write operation to the drive.
 * Write obviously fail.  Reads to a read ahead of sony_buffer_size
 * bytes to help speed operations.  This especially helps since the OS
 * uses 1024 byte blocks and the drive uses 2048 byte blocks.  Since most
 * data access on a CD is done sequentially, this saves a lot of operations.
 */
static void
do_cdu31a_request(void)
{
   int block;
   int nblock;
   unsigned char res_reg[12];
   unsigned int res_size;
   int num_retries;
   unsigned long flags;


#if DEBUG
         printk("Entering do_cdu31a_request\n");
#endif

   /* 
    * Make sure no one else is using the driver; wait for them
    * to finish if it is so.
    */
   save_flags(flags);
   cli();
   while (sony_inuse)
   {
      interruptible_sleep_on(&sony_wait);
      if (signal_pending(current))
      {
         restore_flags(flags);
         if (CURRENT && CURRENT->rq_status != RQ_INACTIVE)
         {
            end_request(0);
         }
         restore_flags(flags);
#if DEBUG
         printk("Leaving do_cdu31a_request at %d\n", __LINE__);
#endif
         return;
      }
   }
   sony_inuse = 1;
   has_cd_task = current;

   /* Get drive status before doing anything. */
   while (handle_sony_cd_attention())
      ;

   /* Make sure we have a valid TOC. */
   sony_get_toc(); 

   spin_unlock_irq(&io_request_lock);

   /* Make sure the timer is cancelled. */
   del_timer(&cdu31a_abort_timer);

   while (1)
   {
cdu31a_request_startover:
      /*
       * The beginning here is stolen from the hard disk driver.  I hope
       * it's right.
       */
      if (!(CURRENT) || CURRENT->rq_status == RQ_INACTIVE)
      {
         goto end_do_cdu31a_request;
      }

      if (!sony_spun_up)
      {
         scd_spinup();
      }

      /* I don't use INIT_REQUEST because it calls return, which would
         return without unlocking the device.  It shouldn't matter,
         but just to be safe... */
      if (MAJOR(CURRENT->rq_dev) != MAJOR_NR)
      {
	 panic(DEVICE_NAME ": request list destroyed");
      }
      if (CURRENT->bh)
      {
	 if (!buffer_locked(CURRENT->bh))
         {
	    panic(DEVICE_NAME ": block not locked");
         }
      }

      block = CURRENT->sector;
      nblock = CURRENT->nr_sectors;

      if (!sony_toc_read)
      {
	 printk("CDU31A: TOC not read\n");
	 end_request(0);
	 goto cdu31a_request_startover;
      }

      switch(CURRENT->cmd)
      {
      case READ:
         /*
          * If the block address is invalid or the request goes beyond the end of
          * the media, return an error.
          */
#if 0
	 if ((block / 4) < sony_toc.start_track_lba)
	 {
            printk("CDU31A: Request before beginning of media\n");
            end_request(0);
            goto cdu31a_request_startover;
	 }
#endif
         if ((block / 4) >= sony_toc.lead_out_start_lba)
         {
            printk("CDU31A: Request past end of media\n");
            end_request(0);
            goto cdu31a_request_startover;
         }
         if (((block + nblock) / 4) >= sony_toc.lead_out_start_lba)
         {
            printk("CDU31A: Request past end of media\n");
            end_request(0);
            goto cdu31a_request_startover;
         }

         num_retries = 0;

try_read_again:
         while (handle_sony_cd_attention())
            ;

         if (!sony_toc_read)
         {
	    printk("CDU31A: TOC not read\n");
	    end_request(0);
	    goto cdu31a_request_startover;
         }

	 /* If no data is left to be read from the drive, start the
	    next request. */
         if (sony_blocks_left == 0)
         {
            if (start_request(block / 4, CDU31A_READAHEAD / 4, 0))
            {
               end_request(0);
               goto cdu31a_request_startover;
            }
         }
	 /* If the requested block is not the next one waiting in
	    the driver, abort the current operation and start a
	    new one. */
         else if (block != sony_next_block)
         {
#if DEBUG
            printk("CDU31A Warning: Read for block %d, expected %d\n",
                   block,
                   sony_next_block);
#endif
            abort_read();
            if (!sony_toc_read)
            {
	       printk("CDU31A: TOC not read\n");
	       end_request(0);
               goto cdu31a_request_startover;
            }
            if (start_request(block / 4, CDU31A_READAHEAD / 4, 0))
            {
               printk("CDU31a: start request failed\n");
               end_request(0);
               goto cdu31a_request_startover;
            }
         }

         read_data_block(CURRENT->buffer, block, nblock, res_reg, &res_size);
         if (res_reg[0] == 0x20)
         {
            if (num_retries > MAX_CDU31A_RETRIES)
            {
               end_request(0);
               goto cdu31a_request_startover;
            }

            num_retries++;
            if (res_reg[1] == SONY_NOT_SPIN_ERR)
            {
               do_sony_cd_cmd(SONY_SPIN_UP_CMD, NULL, 0, res_reg, &res_size);
            }
            else
            {
               printk("CDU31A: %s error for block %d, nblock %d\n", translate_error(res_reg[1]), block, nblock);
            }
            goto try_read_again;
         }
         else
         {
            end_request(1);
         }
         break;
            
      case WRITE: