ide-cd.c

GNU Mach 微内核源代码, 基于美国卡内基美隆大学的 Mach 研究项目

	/* Now we wait for another interrupt. */
	ide_set_handler (drive, &cdrom_pc_intr, WAIT_CMD);
}


static void cdrom_do_pc_continuation (ide_drive_t *drive)
{
	struct request *rq = HWGROUP(drive)->rq;
	struct packet_command *pc = (struct packet_command *)rq->buffer;

	/* Send the command to the drive and return. */
	cdrom_transfer_packet_command (drive, pc->c,
				       sizeof (pc->c), &cdrom_pc_intr);
}


static void cdrom_do_packet_command (ide_drive_t *drive)
{
	int len;
	struct request *rq = HWGROUP(drive)->rq;
	struct packet_command *pc = (struct packet_command *)rq->buffer;

	len = pc->buflen;
	if (len < 0) len = -len;

	pc->stat = 0;

	/* Start sending the command to the drive. */
	cdrom_start_packet_command (drive, len, cdrom_do_pc_continuation);
}


#ifndef MACH
/* Sleep for TIME jiffies.
   Not to be called from an interrupt handler. */
static
void cdrom_sleep (int time)
{
	current->state = TASK_INTERRUPTIBLE;
	current->timeout = jiffies + time;
	schedule ();
}
#endif

static
int cdrom_queue_packet_command (ide_drive_t *drive, struct packet_command *pc)
{
	struct atapi_request_sense my_reqbuf;
	int retries = 10;
	struct request req;

	/* If our caller has not provided a place to stick any sense data,
	   use our own area. */
	if (pc->sense_data == NULL)
		pc->sense_data = &my_reqbuf;
	pc->sense_data->sense_key = 0;

	/* Start of retry loop. */
	do {
		ide_init_drive_cmd (&req);
		req.cmd = PACKET_COMMAND;
		req.buffer = (char *)pc;
		(void) ide_do_drive_cmd (drive, &req, ide_wait);

		if (pc->stat != 0) {
			/* The request failed.  Retry if it was due to a unit
			   attention status
			   (usually means media was changed). */
			struct atapi_request_sense *reqbuf = pc->sense_data;

			if (reqbuf->sense_key == UNIT_ATTENTION)
				;
			else if (reqbuf->sense_key == NOT_READY &&
				 reqbuf->asc == 4) {
				/* The drive is in the process of loading
				   a disk.  Retry, but wait a little to give
				   the drive time to complete the load. */
				cdrom_sleep (HZ);
			} else
				/* Otherwise, don't retry. */
				retries = 0;

			--retries;
		}

		/* End of retry loop. */
	} while (pc->stat != 0 && retries >= 0);


	/* Return an error if the command failed. */
	if (pc->stat != 0)
		return -EIO;
	else {
		/* The command succeeded.  If it was anything other than
		   a request sense, eject, or door lock command,
		   and we think that the door is presently, lock it again.
		   (The door was probably unlocked via an explicit
		   CDROMEJECT ioctl.) */
		if (CDROM_STATE_FLAGS (drive)->door_locked == 0 &&
		    (pc->c[0] != REQUEST_SENSE &&
		     pc->c[0] != ALLOW_MEDIUM_REMOVAL &&
		     pc->c[0] != START_STOP)) {
			(void) cdrom_lockdoor (drive, 1, NULL);
		}
		return 0;
	}
}


/****************************************************************************
 * cdrom driver request routine.
 */

void ide_do_rw_cdrom (ide_drive_t *drive, unsigned long block)
{
	struct request *rq = HWGROUP(drive)->rq;

	if (rq -> cmd == PACKET_COMMAND || rq -> cmd == REQUEST_SENSE_COMMAND)
		cdrom_do_packet_command (drive);
	else if (rq -> cmd == RESET_DRIVE_COMMAND) {
		cdrom_end_request (1, drive);
		ide_do_reset (drive);
		return;
	} else if (rq -> cmd != READ) {
		printk ("ide-cd: bad cmd %d\n", rq -> cmd);
		cdrom_end_request (0, drive);
	} else
		cdrom_start_read (drive, block);
}



/****************************************************************************
 * Ioctl handling.
 *
 * Routines which queue packet commands take as a final argument a pointer
 * to an atapi_request_sense struct.  If execution of the command results
 * in an error with a CHECK CONDITION status, this structure will be filled
 * with the results of the subsequent request sense command.  The pointer
 * can also be NULL, in which case no sense information is returned.
 */

#if ! STANDARD_ATAPI
static inline
int bin2bcd (int x)
{
	return (x%10) | ((x/10) << 4);
}


static inline
int bcd2bin (int x)
{
	return (x >> 4) * 10 + (x & 0x0f);
}

static
void msf_from_bcd (struct atapi_msf *msf)
{
	msf->minute = bcd2bin (msf->minute);
	msf->second = bcd2bin (msf->second);
	msf->frame  = bcd2bin (msf->frame);
}

#endif /* not STANDARD_ATAPI */


static inline
void lba_to_msf (int lba, byte *m, byte *s, byte *f)
{
	lba += CD_BLOCK_OFFSET;
	lba &= 0xffffff;  /* negative lbas use only 24 bits */
	*m = lba / (CD_SECS * CD_FRAMES);
	lba %= (CD_SECS * CD_FRAMES);
	*s = lba / CD_FRAMES;
	*f = lba % CD_FRAMES;
}


static inline
int msf_to_lba (byte m, byte s, byte f)
{
	return (((m * CD_SECS) + s) * CD_FRAMES + f) - CD_BLOCK_OFFSET;
}


static int
cdrom_check_status (ide_drive_t  *drive,
		    struct atapi_request_sense *reqbuf)
{
	struct packet_command pc;

	memset (&pc, 0, sizeof (pc));

	pc.sense_data = reqbuf;
	pc.c[0] = TEST_UNIT_READY;

        /* the Sanyo 3 CD changer uses byte 7 of TEST_UNIT_READY to 
           switch CDs instead of supporting the LOAD_UNLOAD opcode   */

        pc.c[7] = CDROM_STATE_FLAGS (drive)->sanyo_slot % 3;

	return cdrom_queue_packet_command (drive, &pc);
}


/* Lock the door if LOCKFLAG is nonzero; unlock it otherwise. */
static int
cdrom_lockdoor (ide_drive_t *drive, int lockflag,
		struct atapi_request_sense *reqbuf)
{
	struct atapi_request_sense my_reqbuf;
	int stat;
	struct packet_command pc;

	if (reqbuf == NULL)
		reqbuf = &my_reqbuf;

	/* If the drive cannot lock the door, just pretend. */
	if (CDROM_CONFIG_FLAGS (drive)->no_doorlock)
		stat = 0;
	else {
		memset (&pc, 0, sizeof (pc));
		pc.sense_data = reqbuf;

		pc.c[0] = ALLOW_MEDIUM_REMOVAL;
		pc.c[4] = (lockflag != 0);
		stat = cdrom_queue_packet_command (drive, &pc);
	}

	if (stat == 0)
		CDROM_STATE_FLAGS (drive)->door_locked = lockflag;
	else {
		/* If we got an illegal field error, the drive
		   probably cannot lock the door. */
		if (reqbuf->sense_key == ILLEGAL_REQUEST &&
		    (reqbuf->asc == 0x24 || reqbuf->asc == 0x20)) {
			printk ("%s: door locking not supported\n",
				drive->name);
			CDROM_CONFIG_FLAGS (drive)->no_doorlock = 1;
			stat = 0;
			CDROM_STATE_FLAGS (drive)->door_locked = lockflag;
		}
	}
  return stat;
}


/* Eject the disk if EJECTFLAG is 0.
   If EJECTFLAG is 1, try to reload the disk. */
static int
cdrom_eject (ide_drive_t *drive, int ejectflag,
	     struct atapi_request_sense *reqbuf)
{
	struct packet_command pc;

	memset (&pc, 0, sizeof (pc));
	pc.sense_data = reqbuf;

	pc.c[0] = START_STOP;
	pc.c[4] = 2 + (ejectflag != 0);
	return cdrom_queue_packet_command (drive, &pc);
}


static int
cdrom_pause (ide_drive_t *drive, int pauseflag,
	     struct atapi_request_sense *reqbuf)
{
	struct packet_command pc;

	memset (&pc, 0, sizeof (pc));
	pc.sense_data = reqbuf;

	pc.c[0] = SCMD_PAUSE_RESUME;
	pc.c[8] = !pauseflag;
	return cdrom_queue_packet_command (drive, &pc);
}


static int
cdrom_startstop (ide_drive_t *drive, int startflag,
		 struct atapi_request_sense *reqbuf)
{
	struct packet_command pc;

	memset (&pc, 0, sizeof (pc));
	pc.sense_data = reqbuf;

	pc.c[0] = START_STOP;
	pc.c[1] = 1;
	pc.c[4] = startflag;
	return cdrom_queue_packet_command (drive, &pc);
}


static int
cdrom_read_capacity (ide_drive_t *drive, unsigned *capacity,
		     struct atapi_request_sense *reqbuf)
{
	struct {
		unsigned lba;
		unsigned blocklen;
	} capbuf;

	int stat;
	struct packet_command pc;

	memset (&pc, 0, sizeof (pc));
	pc.sense_data = reqbuf;

	pc.c[0] = READ_CAPACITY;
	pc.buffer = (char *)&capbuf;
	pc.buflen = sizeof (capbuf);

	stat = cdrom_queue_packet_command (drive, &pc);
	if (stat == 0)
		*capacity = ntohl (capbuf.lba);

	return stat;
}


static int
cdrom_read_tocentry (ide_drive_t *drive, int trackno, int msf_flag,
                     int format, char *buf, int buflen,
		     struct atapi_request_sense *reqbuf)
{
	struct packet_command pc;

	memset (&pc, 0, sizeof (pc));
	pc.sense_data = reqbuf;

	pc.buffer =  buf;
	pc.buflen = buflen;
	pc.c[0] = SCMD_READ_TOC;
	pc.c[6] = trackno;
	pc.c[7] = (buflen >> 8);
	pc.c[8] = (buflen & 0xff);
	pc.c[9] = (format << 6);
	if (msf_flag) pc.c[1] = 2;
	return cdrom_queue_packet_command (drive, &pc);
}


/* Try to read the entire TOC for the disk into our internal buffer. */
static int
cdrom_read_toc (ide_drive_t *drive,
		struct atapi_request_sense *reqbuf)
{
	int stat, ntracks, i;
	struct atapi_toc *toc = drive->cdrom_info.toc;
	struct {
		struct atapi_toc_header hdr;
		struct atapi_toc_entry  ent;
	} ms_tmp;

	if (toc == NULL) {
		/* Try to allocate space. */
		toc = (struct atapi_toc *) kmalloc (sizeof (struct atapi_toc),
						    GFP_KERNEL);
		drive->cdrom_info.toc = toc;
	}

	if (toc == NULL) {
		printk ("%s: No cdrom TOC buffer!\n", drive->name);
		return -EIO;
	}

	/* Check to see if the existing data is still valid.
	   If it is, just return. */
	if (CDROM_STATE_FLAGS (drive)->toc_valid)
		(void) cdrom_check_status (drive, NULL);

	if (CDROM_STATE_FLAGS (drive)->toc_valid) return 0;

	/* First read just the header, so we know how long the TOC is. */
	stat = cdrom_read_tocentry (drive, 0, 1, 0, (char *)&toc->hdr,
				    sizeof (struct atapi_toc_header) +
				    sizeof (struct atapi_toc_entry),
				    reqbuf);
	if (stat) return stat;

#if ! STANDARD_ATAPI
	if (CDROM_CONFIG_FLAGS (drive)->toctracks_as_bcd) {
		toc->hdr.first_track = bcd2bin (toc->hdr.first_track);
		toc->hdr.last_track  = bcd2bin (toc->hdr.last_track);
	}
#endif  /* not STANDARD_ATAPI */

	ntracks = toc->hdr.last_track - toc->hdr.first_track + 1;
	if (ntracks <= 0) return -EIO;
	if (ntracks > MAX_TRACKS) ntracks = MAX_TRACKS;

	/* Now read the whole schmeer. */
	stat = cdrom_read_tocentry (drive, 0, 1, 0, (char *)&toc->hdr,
				    sizeof (struct atapi_toc_header) +
				    (ntracks+1) *
				      sizeof (struct atapi_toc_entry),
				    reqbuf);
	if (stat) return stat;
	toc->hdr.toc_length = ntohs (toc->hdr.toc_length);

#if ! STANDARD_ATAPI
	if (CDROM_CONFIG_FLAGS (drive)->toctracks_as_bcd) {
		toc->hdr.first_track = bcd2bin (toc->hdr.first_track);
		toc->hdr.last_track  = bcd2bin (toc->hdr.last_track);
	}
#endif  /* not STANDARD_ATAPI */

	for (i=0; i<=ntracks; i++) {
#if ! STANDARD_ATAPI
		if (CDROM_CONFIG_FLAGS (drive)->tocaddr_as_bcd) {
			if (CDROM_CONFIG_FLAGS (drive)->toctracks_as_bcd)
				toc->ent[i].track = bcd2bin (toc->ent[i].track);
			msf_from_bcd (&toc->ent[i].addr.msf);
		}
#endif  /* not STANDARD_ATAPI */
		toc->ent[i].addr.lba = msf_to_lba (toc->ent[i].addr.msf.minute,
						   toc->ent[i].addr.msf.second,
						   toc->ent[i].addr.msf.frame);
	}

	/* Read the multisession information. */
	stat = cdrom_read_tocentry (drive, 0, 1, 1,
				    (char *)&ms_tmp, sizeof (ms_tmp),
				    reqbuf);
	if (stat) return stat;

#if ! STANDARD_ATAPI
	if (CDROM_CONFIG_FLAGS (drive)->tocaddr_as_bcd)
		msf_from_bcd (&ms_tmp.ent.addr.msf);
#endif  /* not STANDARD_ATAPI */

	toc->last_session_lba = msf_to_lba (ms_tmp.ent.addr.msf.minute,
					    ms_tmp.ent.addr.msf.second,
					    ms_tmp.ent.addr.msf.frame);

	toc->xa_flag = (ms_tmp.hdr.first_track != ms_tmp.hdr.last_track);

	/* Now try to get the total cdrom capacity. */
	stat = cdrom_read_capacity (drive, &toc->capacity, reqbuf);
	if (stat) toc->capacity = 0x1fffff;

	HWIF(drive)->gd->sizes[drive->select.b.unit << PARTN_BITS]
		= toc->capacity * SECTORS_PER_FRAME;
	drive->part[0].nr_sects = toc->capacity * SECTORS_PER_FRAME;