2 files changed, 44 insertions, 0 deletions

diff --git a/drivers/ata/libata-acpi.c b/drivers/ata/libata-acpi.c
index 43af2e06d44..dc9842ec6f0 100644
--- a/drivers/ata/libata-acpi.c
+++ b/drivers/ata/libata-acpi.c
@@ -297,6 +297,44 @@ static int ata_dev_get_GTF(struct ata_device *dev, struct ata_acpi_gtf **gtf,
 }
 
 /**
+ * ata_acpi_cbl_80wire          -       Check for 80 wire cable
+ * @ap: Port to check
+ *
+ * Return 1 if the ACPI mode data for this port indicates the BIOS selected
+ * an 80wire mode.
+ */
+
+int ata_acpi_cbl_80wire(struct ata_port *ap)
+{
+        struct ata_acpi_gtm gtm;
+        int valid = 0;
+        
+        /* No _GTM data, no information */
+        if (ata_acpi_gtm(ap, &gtm) < 0)
+                return 0;
+                
+        /* Split timing, DMA enabled */
+        if ((gtm.flags & 0x11) == 0x11 && gtm.drive[0].dma < 55)
+                valid |= 1;
+        if ((gtm.flags & 0x14) == 0x14 && gtm.drive[1].dma < 55)
+                valid |= 2;
+        /* Shared timing, DMA enabled */
+        if ((gtm.flags & 0x11) == 0x01 && gtm.drive[0].dma < 55)
+                valid |= 1;
+        if ((gtm.flags & 0x14) == 0x04 && gtm.drive[0].dma < 55)
+                valid |= 2;
+
+        /* Drive check */
+        if ((valid & 1) && ata_dev_enabled(&ap->link.device[0]))
+                return 1;
+        if ((valid & 2) && ata_dev_enabled(&ap->link.device[1]))
+                return 1;
+        return 0;
+}
+
+EXPORT_SYMBOL_GPL(ata_acpi_cbl_80wire);
+
+/**
  * taskfile_load_raw - send taskfile registers to host controller
  * @dev: target ATA device
  * @gtf: raw ATA taskfile register set (0x1f1 - 0x1f7)
diff --git a/include/linux/libata.h b/include/linux/libata.h
index 9295cd541ff..382898ef654 100644
--- a/include/linux/libata.h
+++ b/include/linux/libata.h
@@ -885,6 +885,12 @@ enum {
                                   ATA_TIMING_CYCLE | ATA_TIMING_UDMA,
 };
 
+/* libata-acpi.c */
+#ifdef CONFIG_ATA_ACPI
+extern int ata_acpi_cbl_80wire(struct ata_port *ap);
+#else
+static inline int ata_acpi_cbl_80wire(struct ata_port *ap) { return 0; }
+#endif
 
 #ifdef CONFIG_PCI
 struct pci_bits {