drivers/usb/storage/cypress_atacb.c

   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  */
  39 void 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;
 190 invalid_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));
 196 end:
 197         memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
 198         if (srb->cmnd[0] == ATA_12)
 199                 srb->cmd_len = 12;
 200 }