root/drivers/usb/storage/cypress_atacb.c

DEFINITIONS

1. cypress_atacb_passthrough
2. cypress_probe

   1 // SPDX-License-Identifier: GPL-2.0+
   2 /*
   3  * Support for emulating SAT (ata pass through) on devices based
   4  *       on the Cypress USB/ATA bridge supporting ATACB.
   5  *
   6  * Copyright (c) 2008 Matthieu Castet (castet.matthieu@free.fr)
   7  */
   8 
   9 #include <linux/module.h>
  10 #include <scsi/scsi.h>
  11 #include <scsi/scsi_cmnd.h>
  12 #include <scsi/scsi_eh.h>
  13 #include <linux/ata.h>
  14 
  15 #include "usb.h"
  16 #include "protocol.h"
  17 #include "scsiglue.h"
  18 #include "debug.h"
  19 
  20 #define DRV_NAME "ums-cypress"
  21 
  22 MODULE_DESCRIPTION("SAT support for Cypress USB/ATA bridges with ATACB");
  23 MODULE_AUTHOR("Matthieu Castet <castet.matthieu@free.fr>");
  24 MODULE_LICENSE("GPL");
  25 MODULE_IMPORT_NS(USB_STORAGE);
  26 
  27 /*
  28  * The table of devices
  29  */
  30 #define UNUSUAL_DEV(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax, \
  31                     vendorName, productName, useProtocol, useTransport, \
  32                     initFunction, flags) \
  33 { USB_DEVICE_VER(id_vendor, id_product, bcdDeviceMin, bcdDeviceMax), \
  34   .driver_info = (flags) }
  35 
  36 static struct usb_device_id cypress_usb_ids[] = {
  37 #       include "unusual_cypress.h"
  38         { }             /* Terminating entry */
  39 };
  40 MODULE_DEVICE_TABLE(usb, cypress_usb_ids);
  41 
  42 #undef UNUSUAL_DEV
  43 
  44 /*
  45  * The flags table
  46  */
  47 #define UNUSUAL_DEV(idVendor, idProduct, bcdDeviceMin, bcdDeviceMax, \
  48                     vendor_name, product_name, use_protocol, use_transport, \
  49                     init_function, Flags) \
  50 { \
  51         .vendorName = vendor_name,      \
  52         .productName = product_name,    \
  53         .useProtocol = use_protocol,    \
  54         .useTransport = use_transport,  \
  55         .initFunction = init_function,  \
  56 }
  57 
  58 static struct us_unusual_dev cypress_unusual_dev_list[] = {
  59 #       include "unusual_cypress.h"
  60         { }             /* Terminating entry */
  61 };
  62 
  63 #undef UNUSUAL_DEV
  64 
  65 
  66 /*
  67  * ATACB is a protocol used on cypress usb<->ata bridge to
  68  * send raw ATA command over mass storage
  69  * There is a ATACB2 protocol that support LBA48 on newer chip.
  70  * More info that be found on cy7c68310_8.pdf and cy7c68300c_8.pdf
  71  * datasheet from cypress.com.
  72  */
  73 static void cypress_atacb_passthrough(struct scsi_cmnd *srb, struct us_data *us)
  74 {
  75         unsigned char save_cmnd[MAX_COMMAND_SIZE];
  76 
  77         if (likely(srb->cmnd[0] != ATA_16 && srb->cmnd[0] != ATA_12)) {
  78                 usb_stor_transparent_scsi_command(srb, us);
  79                 return;
  80         }
  81 
  82         memcpy(save_cmnd, srb->cmnd, sizeof(save_cmnd));
  83         memset(srb->cmnd, 0, MAX_COMMAND_SIZE);
  84 
  85         /* check if we support the command */
  86         if (save_cmnd[1] >> 5) /* MULTIPLE_COUNT */
  87                 goto invalid_fld;
  88         /* check protocol */
  89         switch ((save_cmnd[1] >> 1) & 0xf) {
  90         case 3: /*no DATA */
  91         case 4: /* PIO in */
  92         case 5: /* PIO out */
  93                 break;
  94         default:
  95                 goto invalid_fld;
  96         }
  97 
  98         /* first build the ATACB command */
  99         srb->cmd_len = 16;
 100 
 101         srb->cmnd[0] = 0x24; /*
 102                               * bVSCBSignature : vendor-specific command
 103                               * this value can change, but most(all ?) manufacturers
 104                               * keep the cypress default : 0x24
 105                               */
 106         srb->cmnd[1] = 0x24; /* bVSCBSubCommand : 0x24 for ATACB */
 107 
 108         srb->cmnd[3] = 0xff - 1; /*
 109                                   * features, sector count, lba low, lba med
 110                                   * lba high, device, command are valid
 111                                   */
 112         srb->cmnd[4] = 1; /* TransferBlockCount : 512 */
 113 
 114         if (save_cmnd[0] == ATA_16) {
 115                 srb->cmnd[ 6] = save_cmnd[ 4]; /* features */
 116                 srb->cmnd[ 7] = save_cmnd[ 6]; /* sector count */
 117                 srb->cmnd[ 8] = save_cmnd[ 8]; /* lba low */
 118                 srb->cmnd[ 9] = save_cmnd[10]; /* lba med */
 119                 srb->cmnd[10] = save_cmnd[12]; /* lba high */
 120                 srb->cmnd[11] = save_cmnd[13]; /* device */
 121                 srb->cmnd[12] = save_cmnd[14]; /* command */
 122 
 123                 if (save_cmnd[1] & 0x01) {/* extended bit set for LBA48 */
 124                         /* this could be supported by atacb2 */
 125                         if (save_cmnd[3] || save_cmnd[5] || save_cmnd[7] || save_cmnd[9]
 126                                         || save_cmnd[11])
 127                                 goto invalid_fld;
 128                 }
 129         } else { /* ATA12 */
 130                 srb->cmnd[ 6] = save_cmnd[3]; /* features */
 131                 srb->cmnd[ 7] = save_cmnd[4]; /* sector count */
 132                 srb->cmnd[ 8] = save_cmnd[5]; /* lba low */
 133                 srb->cmnd[ 9] = save_cmnd[6]; /* lba med */
 134                 srb->cmnd[10] = save_cmnd[7]; /* lba high */
 135                 srb->cmnd[11] = save_cmnd[8]; /* device */
 136                 srb->cmnd[12] = save_cmnd[9]; /* command */
 137 
 138         }
 139         /* Filter SET_FEATURES - XFER MODE command */
 140         if ((srb->cmnd[12] == ATA_CMD_SET_FEATURES)
 141                         && (srb->cmnd[6] == SETFEATURES_XFER))
 142                 goto invalid_fld;
 143 
 144         if (srb->cmnd[12] == ATA_CMD_ID_ATA || srb->cmnd[12] == ATA_CMD_ID_ATAPI)
 145                 srb->cmnd[2] |= (1<<7); /* set  IdentifyPacketDevice for these cmds */
 146 
 147 
 148         usb_stor_transparent_scsi_command(srb, us);
 149 
 150         /* if the device doesn't support ATACB */
 151         if (srb->result == SAM_STAT_CHECK_CONDITION &&
 152                         memcmp(srb->sense_buffer, usb_stor_sense_invalidCDB,
 153                                 sizeof(usb_stor_sense_invalidCDB)) == 0) {
 154                 usb_stor_dbg(us, "cypress atacb not supported ???\n");
 155                 goto end;
 156         }
 157 
 158         /*
 159          * if ck_cond flags is set, and there wasn't critical error,
 160          * build the special sense
 161          */
 162         if ((srb->result != (DID_ERROR << 16) &&
 163                                 srb->result != (DID_ABORT << 16)) &&
 164                         save_cmnd[2] & 0x20) {
 165                 struct scsi_eh_save ses;
 166                 unsigned char regs[8];
 167                 unsigned char *sb = srb->sense_buffer;
 168                 unsigned char *desc = sb + 8;
 169                 int tmp_result;
 170 
 171                 /* build the command for reading the ATA registers */
 172                 scsi_eh_prep_cmnd(srb, &ses, NULL, 0, sizeof(regs));
 173 
 174                 /*
 175                  * we use the same command as before, but we set
 176                  * the read taskfile bit, for not executing atacb command,
 177                  * but reading register selected in srb->cmnd[4]
 178                  */
 179                 srb->cmd_len = 16;
 180                 srb->cmnd = ses.cmnd;
 181                 srb->cmnd[2] = 1;
 182 
 183                 usb_stor_transparent_scsi_command(srb, us);
 184                 memcpy(regs, srb->sense_buffer, sizeof(regs));
 185                 tmp_result = srb->result;
 186                 scsi_eh_restore_cmnd(srb, &ses);
 187                 /* we fail to get registers, report invalid command */
 188                 if (tmp_result != SAM_STAT_GOOD)
 189                         goto invalid_fld;
 190 
 191                 /* build the sense */
 192                 memset(sb, 0, SCSI_SENSE_BUFFERSIZE);
 193 
 194                 /* set sk, asc for a good command */
 195                 sb[1] = RECOVERED_ERROR;
 196                 sb[2] = 0; /* ATA PASS THROUGH INFORMATION AVAILABLE */
 197                 sb[3] = 0x1D;
 198 
 199                 /*
 200                  * XXX we should generate sk, asc, ascq from status and error
 201                  * regs
 202                  * (see 11.1 Error translation ATA device error to SCSI error
 203                  * map, and ata_to_sense_error from libata.)
 204                  */
 205 
 206                 /* Sense data is current and format is descriptor. */
 207                 sb[0] = 0x72;
 208                 desc[0] = 0x09; /* ATA_RETURN_DESCRIPTOR */
 209 
 210                 /* set length of additional sense data */
 211                 sb[7] = 14;
 212                 desc[1] = 12;
 213 
 214                 /* Copy registers into sense buffer. */
 215                 desc[ 2] = 0x00;
 216                 desc[ 3] = regs[1];  /* features */
 217                 desc[ 5] = regs[2];  /* sector count */
 218                 desc[ 7] = regs[3];  /* lba low */
 219                 desc[ 9] = regs[4];  /* lba med */
 220                 desc[11] = regs[5];  /* lba high */
 221                 desc[12] = regs[6];  /* device */
 222                 desc[13] = regs[7];  /* command */
 223 
 224                 srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
 225         }
 226         goto end;
 227 invalid_fld:
 228         srb->result = (DRIVER_SENSE << 24) | SAM_STAT_CHECK_CONDITION;
 229 
 230         memcpy(srb->sense_buffer,
 231                         usb_stor_sense_invalidCDB,
 232                         sizeof(usb_stor_sense_invalidCDB));
 233 end:
 234         memcpy(srb->cmnd, save_cmnd, sizeof(save_cmnd));
 235         if (srb->cmnd[0] == ATA_12)
 236                 srb->cmd_len = 12;
 237 }
 238 
 239 static struct scsi_host_template cypress_host_template;
 240 
 241 static int cypress_probe(struct usb_interface *intf,
 242                          const struct usb_device_id *id)
 243 {
 244         struct us_data *us;
 245         int result;
 246         struct usb_device *device;
 247 
 248         result = usb_stor_probe1(&us, intf, id,
 249                         (id - cypress_usb_ids) + cypress_unusual_dev_list,
 250                         &cypress_host_template);
 251         if (result)
 252                 return result;
 253 
 254         /*
 255          * Among CY7C68300 chips, the A revision does not support Cypress ATACB
 256          * Filter out this revision from EEPROM default descriptor values
 257          */
 258         device = interface_to_usbdev(intf);
 259         if (device->descriptor.iManufacturer != 0x38 ||
 260             device->descriptor.iProduct != 0x4e ||
 261             device->descriptor.iSerialNumber != 0x64) {
 262                 us->protocol_name = "Transparent SCSI with Cypress ATACB";
 263                 us->proto_handler = cypress_atacb_passthrough;
 264         } else {
 265                 us->protocol_name = "Transparent SCSI";
 266                 us->proto_handler = usb_stor_transparent_scsi_command;
 267         }
 268 
 269         result = usb_stor_probe2(us);
 270         return result;
 271 }
 272 
 273 static struct usb_driver cypress_driver = {
 274         .name =         DRV_NAME,
 275         .probe =        cypress_probe,
 276         .disconnect =   usb_stor_disconnect,
 277         .suspend =      usb_stor_suspend,
 278         .resume =       usb_stor_resume,
 279         .reset_resume = usb_stor_reset_resume,
 280         .pre_reset =    usb_stor_pre_reset,
 281         .post_reset =   usb_stor_post_reset,
 282         .id_table =     cypress_usb_ids,
 283         .soft_unbind =  1,
 284         .no_dynamic_id = 1,
 285 };
 286 
 287 module_usb_stor_driver(cypress_driver, cypress_host_template, DRV_NAME);