[libata] Add ATA transport class

This is a scheleton for libata transport class.
All information is read only, exporting information from libata:
- ata_port class: one per ATA port
- ata_link class: one per ATA port or 15 for SATA Port Multiplier
- ata_device class: up to 2 for PATA link, usually one for SATA.

Signed-off-by: Gwendal Grignou <gwendal@google.com>
Reviewed-by: Grant Grundler <grundler@google.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/include/linux/libata.h b/include/linux/libata.h
index 45fb2967b66d..c50f66d4382c 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -604,6 +604,7 @@ struct ata_device {
         union acpi_object       *gtf_cache;
         unsigned int            gtf_filter;
 #endif
+        struct device           tdev;
         /* n_sector is CLEAR_BEGIN, read comment above CLEAR_BEGIN */
         u64                     n_sectors;      /* size of device, if ATA */
         u64                     n_native_sectors; /* native size, if ATA */
@@ -690,6 +691,7 @@ struct ata_link {
         struct ata_port         *ap;
         int                     pmp;            /* port multiplier port # */
 
+        struct device           tdev;
         unsigned int            active_tag;     /* active tag on this link */
         u32                     sactive;        /* active NCQ commands */
 
@@ -707,6 +709,8 @@ struct ata_link {
 
         struct ata_device       device[ATA_MAX_DEVICES];
 };
+#define ATA_LINK_CLEAR_BEGIN            offsetof(struct ata_link, active_tag)
+#define ATA_LINK_CLEAR_END              offsetof(struct ata_link, device[0])
 
 struct ata_port {
         struct Scsi_Host        *scsi_host; /* our co-allocated scsi host */
@@ -752,6 +756,7 @@ struct ata_port {
         struct ata_port_stats   stats;
         struct ata_host         *host;
         struct device           *dev;
+        struct device           tdev;
 
         struct mutex            scsi_scan_mutex;
         struct delayed_work     hotplug_task;