[libata] Introduce ata_id_has_unload()
Add a function to check an ATA device's id for head unload support as
specified in ATA-7.
Signed-off-by: Elias Oltmanns <eo@nebensachen.de>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
diff --git a/include/linux/ata.h b/include/linux/ata.h
index 8a12d718..a26ebd2 100644
--- a/include/linux/ata.h
+++ b/include/linux/ata.h
@@ -667,6 +667,15 @@
return 0;
}
+static inline int ata_id_has_unload(const u16 *id)
+{
+ if (ata_id_major_version(id) >= 7 &&
+ (id[ATA_ID_CFSSE] & 0xC000) == 0x4000 &&
+ id[ATA_ID_CFSSE] & (1 << 13))
+ return 1;
+ return 0;
+}
+
static inline int ata_id_current_chs_valid(const u16 *id)
{
/* For ATA-1 devices, if the INITIALIZE DEVICE PARAMETERS command