/*
   * Header file for SCSI device handler infrastruture.
   *
   * Modified version of patches posted by Mike Christie <michaelc@cs.wisc.edu>
   *
   * 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.,
   * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
   *
   * Copyright IBM Corporation, 2007
   *      Authors:
   *               Chandra Seetharaman <sekharan@us.ibm.com>
   *               Mike Anderson <andmike@linux.vnet.ibm.com>
   */
  
  #include <scsi/scsi_device.h>
  
  enum {
  	SCSI_DH_OK = 0,
  	/*
  	 * device errors
  	 */
  	SCSI_DH_DEV_FAILED,	/* generic device error */
  	SCSI_DH_DEV_TEMP_BUSY,

  	SCSI_DH_DEV_UNSUPP,	/* device handler not supported */

  	SCSI_DH_DEVICE_MAX,	/* max device blkerr definition */
  
  	/*
  	 * transport errors
  	 */
  	SCSI_DH_NOTCONN = SCSI_DH_DEVICE_MAX + 1,
  	SCSI_DH_CONN_FAILURE,
  	SCSI_DH_TRANSPORT_MAX,	/* max transport blkerr definition */
  
  	/*
  	 * driver and generic errors
  	 */
  	SCSI_DH_IO = SCSI_DH_TRANSPORT_MAX + 1,	/* generic error */
  	SCSI_DH_INVALID_IO,
  	SCSI_DH_RETRY,		/* retry the req, but not immediately */
  	SCSI_DH_IMM_RETRY,	/* immediately retry the req */
  	SCSI_DH_TIMED_OUT,
  	SCSI_DH_RES_TEMP_UNAVAIL,
  	SCSI_DH_DEV_OFFLINED,

  	SCSI_DH_NOMEM,

  	SCSI_DH_NOSYS,
  	SCSI_DH_DRIVER_MAX,
  };

  
  typedef void (*activate_complete)(void *, int);
  struct scsi_device_handler {
  	/* Used by the infrastructure */
  	struct list_head list; /* list of scsi_device_handlers */
  
  	/* Filled by the hardware handler */
  	struct module *module;
  	const char *name;
  	int (*check_sense)(struct scsi_device *, struct scsi_sense_hdr *);
  	int (*attach)(struct scsi_device *);
  	void (*detach)(struct scsi_device *);
  	int (*activate)(struct scsi_device *, activate_complete, void *);
  	int (*prep_fn)(struct scsi_device *, struct request *);
  	int (*set_params)(struct scsi_device *, const char *);

  	void (*rescan)(struct scsi_device *);

  };

  #ifdef CONFIG_SCSI_DH

  extern int scsi_dh_activate(struct request_queue *, activate_complete, void *);

  extern int scsi_dh_attach(struct request_queue *, const char *);

  extern const char *scsi_dh_attached_handler_name(struct request_queue *, gfp_t);

  extern int scsi_dh_set_params(struct request_queue *, const char *);

  #else

  static inline int scsi_dh_activate(struct request_queue *req,
  					activate_complete fn, void *data)

  {

  	fn(data, 0);

  	return 0;
  }

  static inline int scsi_dh_attach(struct request_queue *req, const char *name)
  {
  	return SCSI_DH_NOSYS;
  }

  static inline const char *scsi_dh_attached_handler_name(struct request_queue *q,
  							gfp_t gfp)
  {
  	return NULL;
  }

  static inline int scsi_dh_set_params(struct request_queue *req, const char *params)
  {
  	return -SCSI_DH_NOSYS;
  }

  #endif