cm206.c

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      del_timer(&cd->timer);
      wake_up_interruptible(&cd->uart);
    }
  }
  /* data ready in fifo? */
  else if (cd->intr_ds & ds_data_ready) { 
    if (cd->background) ++cd->adapter_last;
    if (waitqueue_active(&cd->data) && (cd->wait_back || !cd->background)) {
      del_timer(&cd->timer);
      wake_up_interruptible(&cd->data);
    }
    stats(data_ready);
  }
  /* ready to issue a write command? */
  else if (cd->command && cd->intr_ls & ls_transmitter_buffer_empty) {
    outw(dc_normal | (inw(r_data_status) & 0x7f), r_data_control);
    outw(cd->command, r_uart_transmit);
    cd->command=0;
    if (!cd->background) wake_up_interruptible(&cd->uart);
  }
  /* now treat errors (at least, identify them for debugging) */
  else if (cd->intr_ds & ds_fifo_overflow) {
    debug(("Fifo overflow at sectors 0x%x\n", cd->sector_first));
    fool = inw(r_fifo_output_buffer);	/* de-assert the interrupt */
    cd->fifo_overflowed=1;	/* signal one word less should be read */
    stats(fifo_overflow);
  }
  else if (cd->intr_ds & ds_data_error) {
    debug(("Data error at sector 0x%x\n", cd->sector_first));
    stats(data_error);
  }
  else if (cd->intr_ds & ds_crc_error) {
    debug(("CRC error at sector 0x%x\n", cd->sector_first));
    stats(crc_error);
  }
  else if (cd->intr_ds & ds_sync_error) {
    debug(("Sync at sector 0x%x\n", cd->sector_first));
    stats(sync_error);
  }
  else if (cd->intr_ds & ds_toc_ready) {
    /* do something appropriate */
  }
  /* couldn't see why this interrupt, maybe due to init */
  else {			
    outw(dc_normal | READ_AHEAD, r_data_control);
    stats(lost_intr);
  }
  if (cd->background && (cd->adapter_last-cd->adapter_first == cd->max_sectors
			 || cd->fifo_overflowed))
    mark_bh(CM206_BH);	/* issue a stop read command */
  stats(interrupt);
}

/* we have put the address of the wait queue in who */
void cm206_timeout(unsigned long who)
{
  cd->timed_out = 1;
  debug(("Timing out\n"));
  wake_up_interruptible((wait_queue_head_t *)who);
}

/* This function returns 1 if a timeout occurred, 0 if an interrupt
   happened */
int sleep_or_timeout(wait_queue_head_t *wait, int timeout)
{
  cd->timed_out=0;
  cd->timer.data=(unsigned long) wait;
  cd->timer.expires = jiffies + timeout;
  add_timer(&cd->timer);
  debug(("going to sleep\n"));
  interruptible_sleep_on(wait);
  del_timer(&cd->timer);
  if (cd->timed_out) {
    cd->timed_out = 0;
    return 1;
  }
  else return 0;
}

void cm206_delay(int nr_jiffies) 
{
  DECLARE_WAIT_QUEUE_HEAD(wait);
  sleep_or_timeout(&wait, nr_jiffies);
}

void send_command(int command)
{
  debug(("Sending 0x%x\n", command));
  if (!(inw(r_line_status) & ls_transmitter_buffer_empty)) {
    cd->command = command;
    cli();			/* don't interrupt before sleep */
    outw(dc_mask_sync_error | dc_no_stop_on_error | 
	 (inw(r_data_status) & 0x7f), r_data_control);
    /* interrupt routine sends command */
    if (sleep_or_timeout(&cd->uart, UART_TIMEOUT)) {
      debug(("Time out on write-buffer\n"));
      stats(write_timeout);
      outw(command, r_uart_transmit);
    }
    debug(("Write commmand delayed\n"));
  }
  else outw(command, r_uart_transmit);
}

uch receive_byte(int timeout)
{
  uch ret;
  cli();
  debug(("cli\n"));
  ret = cd->ur[cd->ur_r];
  if (cd->ur_r != cd->ur_w) {
    sti();
    debug(("returning #%d: 0x%x\n", cd->ur_r, cd->ur[cd->ur_r]));
    cd->ur_r++; cd->ur_r %= UR_SIZE;
    return ret;
  } 
  else if (sleep_or_timeout(&cd->uart, timeout)) { /* does sti() */
    debug(("Time out on receive-buffer\n"));
#ifdef STATISTICS
    if (timeout==UART_TIMEOUT) stats(receive_timeout) /* no `;'! */
    else stats(dsb_timeout);
#endif
    return 0xda;
  }
  ret = cd->ur[cd->ur_r];  
  debug(("slept; returning #%d: 0x%x\n", cd->ur_r, cd->ur[cd->ur_r]));
  cd->ur_r++; cd->ur_r %= UR_SIZE;
  return ret;
}

inline uch receive_echo(void)
{
  return receive_byte(UART_TIMEOUT);
}

inline uch send_receive(int command)
{
  send_command(command);
  return receive_echo();
}

inline uch wait_dsb(void)
{
  return receive_byte(DSB_TIMEOUT);
}

int type_0_command(int command, int expect_dsb)
{
  int e;
  clear_ur();
  if (command != (e=send_receive(command))) {
    debug(("command 0x%x echoed as 0x%x\n", command, e));
    stats(echo);
    return -1;
  }
  if (expect_dsb) {
    cd->dsb = wait_dsb();	/* wait for command to finish */
  }
  return 0;
}

int type_1_command(int command, int bytes, uch * status) /* returns info */
{
  int i;
  if (type_0_command(command,0)) return -1;
  for(i=0; i<bytes; i++) 
    status[i] = send_receive(c_gimme);
  return 0;
}  

/* This function resets the adapter card. We'd better not do this too
 * often, because it tends to generate `lost interrupts.' */
void reset_cm260(void)
{
  outw(dc_normal | dc_initialize | READ_AHEAD, r_data_control);
  udelay(10);			/* 3.3 mu sec minimum */
  outw(dc_normal | READ_AHEAD, r_data_control);
}

/* fsm: frame-sec-min from linear address; one of many */
void fsm(int lba, uch * fsm) 
{
  fsm[0] = lba % 75;
  lba /= 75; lba += 2;
  fsm[1] = lba % 60; fsm[2] = lba / 60;
}

inline int fsm2lba(uch * fsm) 
{
  return fsm[0] + 75*(fsm[1]-2 + 60*fsm[2]);
}

inline int f_s_m2lba(uch f, uch s, uch m)
{
  return f + 75*(s-2 + 60*m);
}

int start_read(int start) 
{
  uch read_sector[4] = {c_read_data, };
  int i, e;

  fsm(start, &read_sector[1]);
  clear_ur();
  for (i=0; i<4; i++) 
    if (read_sector[i] != (e=send_receive(read_sector[i]))) {
      debug(("read_sector: %x echoes %x\n", read_sector[i], e));
      stats(echo);
      if (e==0xff) {		/* this seems to happen often */
	e = receive_echo();
	debug(("Second try %x\n", e));
	if (e!=read_sector[i]) return -1;
      }
    }
  return 0;
}

int stop_read(void)
{
  int e;
  type_0_command(c_stop,0);
  if((e=receive_echo()) != 0xff) {
    debug(("c_stop didn't send 0xff, but 0x%x\n", e));
    stats(stop_0xff);
    return -1;
  }
  return 0;
}  

/* This function starts to read sectors in adapter memory, the
   interrupt routine should stop the read. In fact, the bottom_half
   routine takes care of this. Set a flag `background' in the cd
   struct to indicate the process. */

int read_background(int start, int reading)
{
  if (cd->background) return -1; /* can't do twice */
  outw(dc_normal | BACK_AHEAD, r_data_control);
  if (!reading && start_read(start)) return -2;
  cd->adapter_first = cd->adapter_last = start; 
  cd->background = 1;		/* flag a read is going on */
  return 0;
}

#ifdef USE_INSW
#define transport_data insw
#else
/* this routine implements insw(,,). There was a time i had the
   impression that there would be any difference in error-behaviour. */
void transport_data(int port, ush * dest, int count) 
{
  int i;
  ush * d;
  for (i=0, d=dest; i<count; i++, d++) 
    *d = inw(port);
}
#endif


#define MAX_TRIES 100
int read_sector(int start)
{
  int tries=0;
  if (cd->background) {
    cd->background=0;
    cd->adapter_last = -1;	/* invalidate adapter memory */
    stop_read();
  }
  cd->fifo_overflowed=0;
  reset_cm260();		/* empty fifo etc. */
  if (start_read(start)) return -1;
  do {
    if (sleep_or_timeout(&cd->data, DATA_TIMEOUT)) {
      debug(("Read timed out sector 0x%x\n", start));
      stats(read_timeout);
      stop_read();
      return -3;		
    } 
    tries++;
  } while (cd->intr_ds & ds_fifo_empty && tries < MAX_TRIES);
  if (tries>1) debug(("Took me some tries\n"))
  else if (tries == MAX_TRIES) 
    debug(("MAX_TRIES tries for read sector\n"));
  transport_data(r_fifo_output_buffer, cd->sector, 
		 READ_AHEAD*RAW_SECTOR_SIZE/2);
  if (read_background(start+READ_AHEAD,1)) stats(read_background);
  cd->sector_first = start; cd->sector_last = start+READ_AHEAD;
  stats(read_restarted);
  return 0;
}

/* The function of bottom-half is to send a stop command to the drive
   This isn't easy because the routine is not `owned' by any process;
   we can't go to sleep! The variable cd->background gives the status:
   0 no read pending
   1 a read is pending
   2 c_stop waits for write_buffer_empty
   3 c_stop waits for receive_buffer_full: echo
   4 c_stop waits for receive_buffer_full: 0xff
*/

void cm206_bh(void)
{
  debug(("bh: %d\n", cd->background));
  switch (cd->background) {
  case 1:
    stats(bh);
    if (!(cd->intr_ls & ls_transmitter_buffer_empty)) {
      cd->command = c_stop;
      outw(dc_mask_sync_error | dc_no_stop_on_error | 
	   (inw(r_data_status) & 0x7f), r_data_control);
      cd->background=2;
      break;			/* we'd better not time-out here! */
    }
    else outw(c_stop, r_uart_transmit);
    /* fall into case 2: */
  case 2:			
    /* the write has been satisfied by interrupt routine */
    cd->background=3;
    break;
  case 3:
    if (cd->ur_r != cd->ur_w) {
      if (cd->ur[cd->ur_r] != c_stop) {
	debug(("cm206_bh: c_stop echoed 0x%x\n", cd->ur[cd->ur_r]));
	stats(echo);
      }
      cd->ur_r++; cd->ur_r %= UR_SIZE;
    }
    cd->background++;
    break;
  case 4:
    if (cd->ur_r != cd->ur_w) {
      if (cd->ur[cd->ur_r] != 0xff) {
	debug(("cm206_bh: c_stop reacted with 0x%x\n", cd->ur[cd->ur_r]));
	stats(stop_0xff);
      }
      cd->ur_r++; cd->ur_r %= UR_SIZE;
    }
    cd->background=0;
  }
}

/* This command clears the dsb_possible_media_change flag, so we must 
 * retain it.
 */
void get_drive_status(void)
{
  uch status[2];
  type_1_command(c_drive_status, 2, status); /* this might be done faster */
  cd->dsb=status[0];
  cd->cc=status[1];
  cd->media_changed |= 
    !!(cd->dsb & (dsb_possible_media_change | 
		  dsb_drive_not_ready | dsb_tray_not_closed));
}

void get_disc_status(void)
{
  if (type_1_command(c_disc_status, 7, cd->disc_status)) {
    debug(("get_disc_status: error\n"));
  }
}

/* The new open. The real opening strategy is defined in cdrom.c. */

static int cm206_open(struct cdrom_device_info * cdi, int purpose) 
{
  MOD_INC_USE_COUNT;
  if (!cd->openfiles) {		/* reset only first time */
    cd->background=0;
    reset_cm260();