2 files changed, 58 insertions, 0 deletions

diff --git a/drivers/scsi/libata-scsi.c b/drivers/scsi/libata-scsi.c
index 6a75ec2187fd..f58311b8c050 100644
--- a/drivers/scsi/libata-scsi.c
+++ b/drivers/scsi/libata-scsi.c
@@ -392,6 +392,60 @@ int ata_scsi_error(struct Scsi_Host *host)
 }
 
 /**
+ *      ata_scsi_start_stop_xlat - Translate SCSI START STOP UNIT command
+ *      @qc: Storage for translated ATA taskfile
+ *      @scsicmd: SCSI command to translate
+ *
+ *      Sets up an ATA taskfile to issue STANDBY (to stop) or READ VERIFY
+ *      (to start). Perhaps these commands should be preceded by
+ *      CHECK POWER MODE to see what power mode the device is already in.
+ *      [See SAT revision 5 at www.t10.org]
+ *
+ *      LOCKING:
+ *      spin_lock_irqsave(host_set lock)
+ *
+ *      RETURNS:
+ *      Zero on success, non-zero on error.
+ */
+
+static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc,
+                                             u8 *scsicmd)
+{
+        struct ata_taskfile *tf = &qc->tf;
+
+        tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
+        tf->protocol = ATA_PROT_NODATA;
+        if (scsicmd[1] & 0x1) {
+                ;       /* ignore IMMED bit, violates sat-r05 */
+        }
+        if (scsicmd[4] & 0x2)
+                return 1;       /* LOEJ bit set not supported */
+        if (((scsicmd[4] >> 4) & 0xf) != 0)
+                return 1;       /* power conditions not supported */
+        if (scsicmd[4] & 0x1) {
+                tf->nsect = 1;  /* 1 sector, lba=0 */
+                tf->lbah = 0x0;
+                tf->lbam = 0x0;
+                tf->lbal = 0x0;
+                tf->device |= ATA_LBA;
+                tf->command = ATA_CMD_VERIFY;   /* READ VERIFY */
+        } else {
+                tf->nsect = 0;  /* time period value (0 implies now) */
+                tf->command = ATA_CMD_STANDBY;
+                /* Consider: ATA STANDBY IMMEDIATE command */
+        }
+        /*
+         * Standby and Idle condition timers could be implemented but that
+         * would require libata to implement the Power condition mode page
+         * and allow the user to change it. Changing mode pages requires
+         * MODE SELECT to be implemented.
+         */
+
+        return 0;
+}
+
+
+/**
  *      ata_scsi_flush_xlat - Translate SCSI SYNCHRONIZE CACHE command
  *      @qc: Storage for translated ATA taskfile
  *      @scsicmd: SCSI command to translate (ignored)
@@ -1435,6 +1489,8 @@ static inline ata_xlat_func_t ata_get_xlat_func(struct ata_device *dev, u8 cmd)
         case VERIFY:
         case VERIFY_16:
                 return ata_scsi_verify_xlat;
+        case START_STOP:
+                return ata_scsi_start_stop_xlat;
         }
 
         return NULL;
diff --git a/include/linux/ata.h b/include/linux/ata.h
index ca5fcadf9981..9d25e9886d60 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -108,6 +108,8 @@ enum {
 
         /* ATA device commands */
         ATA_CMD_CHK_POWER       = 0xE5, /* check power mode */
+        ATA_CMD_STANDBY         = 0xE2, /* place in standby power mode */
+        ATA_CMD_IDLE            = 0xE3, /* place in idle power mode */
         ATA_CMD_EDD             = 0x90, /* execute device diagnostic */
         ATA_CMD_FLUSH           = 0xE7,
         ATA_CMD_FLUSH_EXT       = 0xEA,