LXR linux/drivers/usb/storage/cypress

   1/*
   2 * Support for emulating SAT (ata pass through) on devices based
   3 *       on the Cypress USB/ATA bridge supporting ATACB.
   4 *
   5 * Copyright (c) 2008 Matthieu Castet (castet.matthieu@free.fr)
   6 *
   7 * This program is free software; you can redistribute it and/or modify it
   8 * under the terms of the GNU General Public License as published by the
   9 * Free Software Foundation; either version 2, or (at your option) any
  10 * later version.
  11 *
  12 * This program is distributed in the hope that it will be useful, but
  13 * WITHOUT ANY WARRANTY; without even the implied warranty of
  14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15 * General Public License for more details.
  16 *
  17 * You should have received a copy of the GNU General Public License along
  18 * with this program; if not, write to the Free Software Foundation, Inc.,
  19 * 675 Mass Ave, Cambridge, MA 02139, USA.
  20 */
  21
  22#include <scsi/scsi.h>
  23#include <scsi/scsi_cmnd.h>
  24#include <scsi/scsi_eh.h>
  25#include <linux/ata.h>
  26
  27#include "usb.h"
  28#include "protocol.h"
  29#include "scsiglue.h"
  30#include "debug.h"
  31
  32/*
  33 * ATACB is a protocol used on cypress usb<->ata bridge to
  34 * send raw ATA command over mass storage
  35 * There is a ATACB2 protocol that support LBA48 on newer chip.
  36 * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
  37 * datasheet from cypress.com.
  38 */
  39void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)
  40{
  41        unsigned char save_cmnd[MAX_COMMAND_SIZE];
  42
  43        if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {
  44                usb_stor_transparent_scsi_command(srb, us);
  45                return;
  46        }
  47
  48        memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
  49        memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
  50
  51        /* check if we support the command */
  52        if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
  53                goto invalid_fld;
  54        /* check protocol */
  55        switch((save_cmnd[1] >> 1) & 0xf) {
  56                case 3: /*no DATA */
  57                case 4: /* PIO in */
  58                case 5: /* PIO out */
  59                        break;
  60                default:
  61                        goto invalid_fld;
  62        }
  63
  64        /* first build the ATACB command */
  65        srb->cmd_len = 16;
  66
  67        srb->cmnd[0] = 0x24; /* bVSCBSignature : vendor-specific command
  68                                this value can change, but most(all ?) manufacturers
  69                                                        keep the cypress default : 0x24 */
  70        srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */
  71
  72        srb->cmnd[3] = 0xff - 1; /* features, sector count, lba low, lba med
  73                                                                lba high, device, command are valid */
  74        srb->cmnd[4] = 1; /* TransferBlockCount : 512 */
  75
  76        if (save_cmnd[0] == ATA_16) {
  77                srb->cmnd[ 6] = save_cmnd[ 4]; /* features */
  78                srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */
  79                srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */
  80                srb->cmnd[ 9] = save_cmnd[10]; /* lba med */
  81                srb->cmnd[10] = save_cmnd[12]; /* lba high */
  82                srb->cmnd[11] = save_cmnd[13]; /* device */
  83                srb->cmnd[12] = save_cmnd[14]; /* command */
  84
  85                if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
  86                        /* this could be supported by atacb2 */
  87                        if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
  88                                        || save_cmnd[11])
  89                                goto invalid_fld;
  90                }
  91        }
  92        else { /* ATA12 */
  93                srb->cmnd[ 6] = save_cmnd[3]; /* features */
  94                srb->cmnd[ 7] = save_cmnd[4]; /* sector count */
  95                srb->cmnd[ 8] = save_cmnd[5]; /* lba low */
  96                srb->cmnd[ 9] = save_cmnd[6]; /* lba med */
  97                srb->cmnd[10] = save_cmnd[7]; /* lba high */
  98                srb->cmnd[11] = save_cmnd[8]; /* device */
  99                srb->cmnd[12] = save_cmnd[9]; /* command */
 100
 101        }
 102        /* Filter SET_FEATURES - XFER MODE command */
 103        if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
 104                        && (srb->cmnd[6] == SETFEATURES_XFER))
 105                goto invalid_fld;
 106
 107        if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
 108                srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */
 109
 110
 111        usb_stor_transparent_scsi_command(srb, us);
 112
 113        /* if the device doesn't support ATACB
 114         */
 115        if (srb->result == SAM_STAT_CHECK_CONDITION &&
 116                        memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
 117                                sizeof(usb_stor_sense_invalidCDB)) == 0) {
 118                US_DEBUGP("cypress atacb not supported ???\n");
 119                goto end;
 120        }
 121
 122        /* if ck_cond flags is set, and there wasn't critical error,
 123         * build the special sense
 124         */
 125        if ((srb->result != (DID_ERROR << 16) &&
 126                                srb->result != (DID_ABORT << 16)) &&
 127                        save_cmnd[2] & 0x20) {
 128                struct scsi_eh_save ses;
 129                unsigned char regs[8];
 130                unsigned char *sb = srb->sense_buffer;
 131                unsigned char *desc = sb + 8;
 132                int tmp_result;
 133
 134                /* build the command for
 135                 * reading the ATA registers */
 136                scsi_eh_prep_cmnd(srb, &ses, NULL, 0, 0);
 137                srb->sdb.length = sizeof(regs);
 138                sg_init_one(&ses.sense_sgl, regs, srb->sdb.length);
 139                srb->sdb.table.sgl = &ses.sense_sgl;
 140                srb->sc_data_direction = DMA_FROM_DEVICE;
 141                srb->sdb.table.nents = 1;
 142                /* we use the same command as before, but we set
 143                 * the read taskfile bit, for not executing atacb command,
 144                 * but reading register selected in srb->cmnd[4]
 145                 */
 146                srb->cmnd[2] = 1;
 147
 148                usb_stor_transparent_scsi_command(srb, us);
 149                tmp_result = srb->result;
 150                scsi_eh_restore_cmnd(srb, &ses);
 151                /* we fail to get registers, report invalid command */
 152                if (tmp_result != SAM_STAT_GOOD)
 153                        goto invalid_fld;
 154
 155                /* build the sense */
 156                memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
 157
 158                /* set sk, asc for a good command */
 159                sb[1] = RECOVERED_ERROR;
 160                sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
 161                sb[3] = 0x1D;
 162
 163                /* XXX we should generate sk, asc, ascq from status and error
 164                 * regs
 165                 * (see 11.1 Error translation  ATA device error to SCSI error map)
 166                 * and ata_to_sense_error from libata.
 167                 */
 168
 169                /* Sense data is current and format is descriptor. */
 170                sb[0] = 0x72;
 171                desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
 172
 173                /* set length of additional sense data */
 174                sb[7] = 14;
 175                desc[1] = 12;
 176
 177                /* Copy registers into sense buffer. */
 178                desc[ 2] = 0x00;
 179                desc[ 3] = regs[1];  /* features */
 180                desc[ 5] = regs[2];  /* sector count */
 181                desc[ 7] = regs[3];  /* lba low */
 182                desc[ 9] = regs[4];  /* lba med */
 183                desc[11] = regs[5];  /* lba high */
 184                desc[12] = regs[6];  /* device */
 185                desc[13] = regs[7];  /* command */
 186
 187                srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
 188        }
 189        goto end;
 190invalid_fld:
 191        srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
 192
 193        memcpy(srb->sense_buffer,
 194                        usb_stor_sense_invalidCDB,
 195                        sizeof(usb_stor_sense_invalidCDB));
 196end:
 197        memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
 198        if (srb->cmnd[0] == ATA_12)
 199                srb->cmd_len = 12;
 200}
 201