/*      $NetBSD: st_scsi.c,v 1.37 2015/08/24 23:13:15 pooka Exp $ */

/*-
 * Copyright (c) 1998, 2004 The NetBSD Foundation, Inc.
 * All rights reserved.
 *
 * This code is derived from software contributed to The NetBSD Foundation
 * by Charles M. Hannum.
 *
 * 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.
 */

/*
 * Originally written by Julian Elischer (julian@tfs.com)
 * for TRW Financial Systems for use under the MACH(2.5) operating system.
 *
 * TRW Financial Systems, in accordance with their agreement with Carnegie
 * Mellon University, makes this software available to CMU to distribute
 * or use in any manner that they see fit as long as this message is kept with
 * the software. For this reason TFS also grants any other persons or
 * organisations permission to use or modify this software.
 *
 * TFS supplies this software to be publicly redistributed
 * on the understanding that TFS is not responsible for the correct
 * functioning of this software in any circumstances.
 *
 * Ported to run under 386BSD by Julian Elischer (julian@tfs.com) Sept 1992
 * major changes by Julian Elischer (julian@jules.dialix.oz.au) May 1993
 *
 * A lot of rewhacking done by mjacob (mjacob@nas.nasa.gov).
 */

#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: st_scsi.c,v 1.37 2015/08/24 23:13:15 pooka Exp $");

#ifdef _KERNEL_OPT
#include "opt_scsi.h"
#endif

#include <sys/param.h>
#include <sys/device.h>
#include <sys/buf.h>
#include <sys/bufq.h>
#include <sys/conf.h>
#include <sys/kernel.h>
#include <sys/systm.h>

#include <dev/scsipi/scsi_all.h>
#include <dev/scsipi/scsi_tape.h>
#include <dev/scsipi/stvar.h>

static int      st_scsibus_match(device_t, cfdata_t, void *);
static void     st_scsibus_attach(device_t, device_t, void *);
static int      st_scsibus_ops(struct st_softc *, int, int);
static int      st_scsibus_read_block_limits(struct st_softc *, int);
static int      st_scsibus_mode_sense(struct st_softc *, int);
static int      st_scsibus_cmprss(struct st_softc *, int, int);

CFATTACH_DECL_NEW(
        st_scsibus,
        sizeof(struct st_softc),
        st_scsibus_match,
        st_scsibus_attach,
        stdetach,
        NULL
);

static const struct scsipi_inquiry_pattern st_scsibus_patterns[] = {
        {T_SEQUENTIAL, T_REMOV,
         "",         "",                 ""},
};

static int
st_scsibus_match(device_t parent, cfdata_t match, void *aux)
{
        struct scsipibus_attach_args *sa = aux;
        int priority;

        if (SCSIPI_BUSTYPE_TYPE(scsipi_periph_bustype(sa->sa_periph)) !=
            SCSIPI_BUSTYPE_SCSI)
                return 0;

        (void)scsipi_inqmatch(&sa->sa_inqbuf,
            st_scsibus_patterns,
            sizeof(st_scsibus_patterns)/sizeof(st_scsibus_patterns[0]),
            sizeof(st_scsibus_patterns[0]), &priority);
        return priority;
}

static void
st_scsibus_attach(device_t parent, device_t self, void *aux)
{
        struct st_softc *st = device_private(self);

        st->ops = st_scsibus_ops;
        stattach(parent, self, aux);
}

static int
st_scsibus_ops(struct st_softc *st, int op, int flags)
{
        switch(op) {
        case ST_OPS_RBL:
                return st_scsibus_read_block_limits(st, flags);
        case ST_OPS_MODESENSE:
                return st_scsibus_mode_sense(st, flags);
        case ST_OPS_MODESELECT:
                return st_mode_select(st, flags);
        case ST_OPS_CMPRSS_ON:
        case ST_OPS_CMPRSS_OFF:
                return st_scsibus_cmprss(st, flags,
                    (op == ST_OPS_CMPRSS_ON) ? 1 : 0);
        default:
                panic("st_scsibus_ops: invalid op");
                return 0; /* XXX to appease gcc */
        }
        /* NOTREACHED */
}

/*
 * Ask the drive what its min and max blk sizes are.
 */
static int
st_scsibus_read_block_limits(struct st_softc *st, int flags)
{
        struct scsi_block_limits cmd;
        struct scsi_block_limits_data block_limits;
        struct scsipi_periph *periph = st->sc_periph;
        int error;

        /* do a 'Read Block Limits' */
        memset(&cmd, 0, sizeof(cmd));
        cmd.opcode = READ_BLOCK_LIMITS;

        /* do the command, update the global values */
        error = scsipi_command(periph, (void *)&cmd, sizeof(cmd),
            (void *)&block_limits, sizeof(block_limits),
            ST_RETRIES, ST_CTL_TIME, NULL, flags | XS_CTL_DATA_IN);
        if (error)
                return error;

        st->blkmin = _2btol(block_limits.min_length);
        st->blkmax = _3btol(block_limits.max_length);

        SC_DEBUG(periph, SCSIPI_DB3,
            ("(%d <= blksize <= %d)\n", st->blkmin, st->blkmax));
        return 0;
}

/*
 * Get the scsi driver to send a full inquiry to the
 * device and use the results to fill out the global
 * parameter structure.
 *
 * called from:
 * attach
 * open
 * ioctl (to reset original blksize)
 */
static int
st_scsibus_mode_sense(struct st_softc *st, int flags)
{
        u_int scsipi_sense_len;
        int error;
        struct scsipi_sense {
                struct scsi_mode_parameter_header_6 header;
                struct scsi_general_block_descriptor blk_desc;
                u_char sense_data[MAX_PAGE_0_SIZE];
        } scsipi_sense;
        struct scsipi_periph *periph = st->sc_periph;

        scsipi_sense_len = sizeof(scsipi_sense.header) +
                           sizeof(scsipi_sense.blk_desc) +
                           st->page_0_size;

        /*
         * Set up a mode sense
         * We don't need the results. Just print them for our interest's sake,
         * if asked, or if we need it as a template for the mode select store
         * it away.
         */
        error = scsipi_mode_sense(st->sc_periph, 0, SMS_PCTRL_CURRENT,
            &scsipi_sense.header, scsipi_sense_len, flags,
            ST_RETRIES, ST_CTL_TIME);
        if (error)
                return error;

        st->numblks = _3btol(scsipi_sense.blk_desc.nblocks);
        st->media_blksize = _3btol(scsipi_sense.blk_desc.blklen);
        st->media_density = scsipi_sense.blk_desc.density;
        if (scsipi_sense.header.dev_spec & SMH_DSP_WRITE_PROT)
                st->flags |= ST_READONLY;
        else
                st->flags &= ~ST_READONLY;
        SC_DEBUG(periph, SCSIPI_DB3,
            ("density code %d, %d-byte blocks, write-%s, ",
            st->media_density, st->media_blksize,
            st->flags & ST_READONLY ? "protected" : "enabled"));
        SC_DEBUG(periph, SCSIPI_DB3,
            ("%sbuffered\n",
            scsipi_sense.header.dev_spec & SMH_DSP_BUFF_MODE ? "" : "un"));
        if (st->page_0_size)
                memcpy(st->sense_data, scsipi_sense.sense_data,
                    st->page_0_size);
        periph->periph_flags |= PERIPH_MEDIA_LOADED;
        return 0;
}

static int
st_scsibus_cmprss(struct st_softc *st, int flags, int onoff)
{
        u_int scsi_dlen;
        int byte2, page;
        struct scsi_select {
                struct scsi_mode_parameter_header_6 header;
                struct scsi_general_block_descriptor blk_desc;
                u_char pdata[MAX(sizeof(struct scsi_tape_dev_conf_page),
                    sizeof(struct scsi_tape_dev_compression_page))];
        } scsi_pdata;
        struct scsi_tape_dev_conf_page *ptr;
        struct scsi_tape_dev_compression_page *cptr;
        struct scsipi_periph *periph = st->sc_periph;
        int error, ison;

        scsi_dlen = sizeof(scsi_pdata);
        /* Do DATA COMPRESSION page first. */
        page = SMS_PCTRL_CURRENT | 0xf;
        byte2 = 0;

        /*  Do the MODE SENSE command... */
again:
        memset(&scsi_pdata, 0, scsi_dlen);
        error = scsipi_mode_sense(periph, byte2, page,
            &scsi_pdata.header, scsi_dlen, flags, ST_RETRIES, ST_CTL_TIME);

        if (error) {
                if (byte2 != SMS_DBD) {
                        byte2 = SMS_DBD;
                        goto again;
                }
                /* Try a different page? */
                if (page == (SMS_PCTRL_CURRENT | 0xf)) {
                        page = SMS_PCTRL_CURRENT | 0x10;
                        byte2 = 0;
                        goto again;
                }
                return error;
        }

        if (scsi_pdata.header.blk_desc_len)
                ptr = (struct scsi_tape_dev_conf_page *) scsi_pdata.pdata;
        else
                ptr = (struct scsi_tape_dev_conf_page *) &scsi_pdata.blk_desc;

        if ((page & SMS_PAGE_MASK) == 0xf) {
                cptr = (struct scsi_tape_dev_compression_page *) ptr;
                ison = (cptr->dce_dcc & DCP_DCE) != 0;
                if (onoff)
                        cptr->dce_dcc |= DCP_DCE;
                else
                        cptr->dce_dcc &= ~DCP_DCE;
                cptr->pagecode &= ~0x80;
        } else {
                ison =  (ptr->sel_comp_alg != 0);
                if (onoff)
                        ptr->sel_comp_alg = 1;
                else
                        ptr->sel_comp_alg = 0;
                ptr->pagecode &= ~0x80;
                ptr->byte2 = 0;
                ptr->active_partition = 0;
                ptr->wb_full_ratio = 0;
                ptr->rb_empty_ratio = 0;
                ptr->byte8 &= ~0x30;
                ptr->gap_size = 0;
                ptr->byte10 &= ~0xe7;
                ptr->ew_bufsize[0] = 0;
                ptr->ew_bufsize[1] = 0;
                ptr->ew_bufsize[2] = 0;
                ptr->reserved = 0;
        }
        /*
         * There might be a virtue in actually doing the MODE SELECTS,
         * but let's not clog the bus over it.
         */
        if (onoff == ison)
                return 0;

        /* Set up for a mode select */
        scsi_pdata.header.data_length = 0;
        scsi_pdata.header.medium_type = 0;
        if ((st->flags & ST_DONTBUFFER) == 0)
                scsi_pdata.header.dev_spec = SMH_DSP_BUFF_MODE_ON;
        else
                scsi_pdata.header.dev_spec = 0;

        if (scsi_pdata.header.blk_desc_len) {
                scsi_pdata.blk_desc.density = 0;
                scsi_pdata.blk_desc.nblocks[0] = 0;
                scsi_pdata.blk_desc.nblocks[1] = 0;
                scsi_pdata.blk_desc.nblocks[2] = 0;
        }

        /* Do the command */
        error = scsipi_mode_select(periph, SMS_PF, &scsi_pdata.header,
            scsi_dlen, flags, ST_RETRIES, ST_CTL_TIME);

        if (error && (page & SMS_PAGE_MASK) == 0xf) {
                /* Try DEVICE CONFIGURATION page. */
                page = SMS_PCTRL_CURRENT | 0x10;
                goto again;
        }
        return error;
}