/*      $NetBSD: dev_tape.c,v 1.13 2014/03/30 15:20:54 christos Exp $   */

/*-
* Copyright (c) 1998 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Paul Kranenburg.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
*    notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
*    notice, this list of conditions and the following disclaimer in the
*    documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/

/*
* This module implements a "raw device" interface suitable for
* use by the stand-alone I/O library UFS file-system code, and
* possibly for direct access (i.e. boot from tape).
*/

#include <sys/types.h>
#include <machine/prom.h>

#include <lib/libkern/libkern.h>

#include <lib/libsa/stand.h>
#include "libsa.h"
#include "dev_tape.h"

extern int debug;

struct mvmeprom_dskio tape_ioreq;

static int hackprom_diskrd(struct mvmeprom_dskio *);

/*
* This is a special version of devopen() for tape boot.
* In this version, the file name is a numeric string of
* one digit, which is passed to the device open so it
* can open the appropriate tape segment.
*/
int
devopen(struct open_file *f, const char *fname, char **file)
{
       struct devsw *dp;

       *file = (char *)fname;
       dp = &devsw[0];
       f->f_dev = dp;

       /* The following will call tape_open() */
       return dp->dv_open(f, fname);
}

int
tape_open(struct open_file *f, ...)
{
       char *fname;            /* partition number, i.e. "1" */
       int part;
       struct mvmeprom_dskio *ti;
       va_list ap;

       va_start(ap, f);
       fname = va_arg(ap, char *);
       va_end(ap);

       /*
        * Set the tape segment number to the one indicated
        * by the single digit fname passed in above.
        */
       if ((fname[0] < '0') && (fname[0] > '9')) {
               return ENOENT;
       }
       part = fname[0] - '0';

       /*
        * Setup our part of the saioreq.
        * (determines what gets opened)
        */
       ti = &tape_ioreq;
       memset((void *)ti, 0, sizeof(*ti));

       ti->ctrl_lun = bugargs.ctrl_lun;
       ti->dev_lun = bugargs.dev_lun;
       ti->status = 0;
       ti->pbuffer = NULL;
       ti->blk_num = part;
       ti->blk_cnt = 0;
       ti->flag = 0;
       ti->addr_mod = 0;

       f->f_devdata = ti;

       return 0;
}

int
tape_close(struct open_file *f)
{
       f->f_devdata = NULL;
       return 0;
}

#define MVMEPROM_SCALE (512/MVMEPROM_BLOCK_SIZE)

int
tape_strategy(void *devdata, int flag, daddr_t dblk, u_int size, void *buf,
   u_int *rsize)
{
       struct mvmeprom_dskio *ti;
       int ret;

       ti = devdata;

       if (flag != F_READ)
               return EROFS;

       ti->status = 0;
       ti->pbuffer = buf;
       /* don't change block #, set in open */
       ti->blk_cnt = size / (512 / MVMEPROM_SCALE);

       /* work around for stupid '147 prom bug */
       if (bugargs.cputyp == 0x147)
               ret = hackprom_diskrd(ti);
       else
               ret = mvmeprom_diskrd(ti);

       if (ret != 0)
               return EIO;

       *rsize = (ti->blk_cnt / MVMEPROM_SCALE) * 512;
       ti->flag |= IGNORE_FILENUM; /* ignore next time */

       return 0;
}

int
tape_ioctl(struct open_file *f, u_long cmd, void *data)
{

       return EIO;
}

static int
hackprom_diskrd(struct mvmeprom_dskio *ti)
{
       static int blkoffset = 0;

#define hackload_addr   ((char *)0x080000)      /* Load tape segment here */
#define hackload_blocks 0x3000                  /* 3Mb worth */

       if ((ti->flag & IGNORE_FILENUM) == 0) {
               /*
                * First time through. Load the whole tape segment...
                */
               struct mvmeprom_dskio nti;
               int ret;

               nti = *ti;

               nti.pbuffer = hackload_addr;
               nti.blk_cnt = hackload_blocks;
               nti.flag |= END_OF_FILE;

               ret = mvmeprom_diskrd(&nti);

               /*
                * PROM returns 1 on end-of-file. This isn't an
                * error in this instance, just in case you're wondering! ;-)
                */
               if (ret < 0 || ret > 1)
                       return ret;

               blkoffset = 0;
       }

       /*
        * Grab the required number of block(s)
        */
       memcpy(ti->pbuffer, &(hackload_addr[blkoffset]),
           ti->blk_cnt * MVMEPROM_BLOCK_SIZE);

       blkoffset += (ti->blk_cnt * MVMEPROM_BLOCK_SIZE);

       return 0;
}