ide: add short cables support

This patch allows users to override both host and device side cable detection
with "ideX=ata66" kernel parameter.  Thanks to this it should be now possible
to use UDMA > 2 modes on systems (laptops mainly) which use short 40-pin cable
instead of 80-pin one.

Next patches add automatic detection of some systems using short cables.

Changes:

* Rename hwif->udma_four to hwif->cbl and make it u8.

* Convert all existing users accordingly (use ATA_CBL_* defines while at it).  

* Add ATA_CBL_PATA40_SHORT support to ide-iops.c:eighty_ninty_three().

* Use ATA_CBL_PATA40_SHORT for "ideX=ata66" kernel parameter.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Reviewed-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
diff --git a/drivers/ide/pci/serverworks.c b/drivers/ide/pci/serverworks.c
index 09a7aed..1371b5b 100644
--- a/drivers/ide/pci/serverworks.c
+++ b/drivers/ide/pci/serverworks.c
@@ -329,9 +329,9 @@
 	return dev->irq;
 }
 
-static unsigned int __devinit ata66_svwks_svwks (ide_hwif_t *hwif)
+static u8 __devinit ata66_svwks_svwks(ide_hwif_t *hwif)
 {
-	return 1;
+	return ATA_CBL_PATA80;
 }
 
 /* On Dell PowerEdge servers with a CSB5/CSB6, the top two bits
@@ -341,7 +341,7 @@
  * Bit 14 clear = primary IDE channel does not have 80-pin cable.
  * Bit 14 set   = primary IDE channel has 80-pin cable.
  */
-static unsigned int __devinit ata66_svwks_dell (ide_hwif_t *hwif)
+static u8 __devinit ata66_svwks_dell(ide_hwif_t *hwif)
 {
 	struct pci_dev *dev = hwif->pci_dev;
 	if (dev->subsystem_vendor == PCI_VENDOR_ID_DELL &&
@@ -349,8 +349,8 @@
 	    (dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5IDE ||
 	     dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE))
 		return ((1 << (hwif->channel + 14)) &
-			dev->subsystem_device) ? 1 : 0;
-	return 0;
+			dev->subsystem_device) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
+	return ATA_CBL_PATA40;
 }
 
 /* Sun Cobalt Alpine hardware avoids the 80-pin cable
@@ -359,18 +359,18 @@
  *
  * WARNING: this only works on Alpine hardware!
  */
-static unsigned int __devinit ata66_svwks_cobalt (ide_hwif_t *hwif)
+static u8 __devinit ata66_svwks_cobalt(ide_hwif_t *hwif)
 {
 	struct pci_dev *dev = hwif->pci_dev;
 	if (dev->subsystem_vendor == PCI_VENDOR_ID_SUN &&
 	    dev->vendor	== PCI_VENDOR_ID_SERVERWORKS &&
 	    dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB5IDE)
 		return ((1 << (hwif->channel + 14)) &
-			dev->subsystem_device) ? 1 : 0;
-	return 0;
+			dev->subsystem_device) ? ATA_CBL_PATA80 : ATA_CBL_PATA40;
+	return ATA_CBL_PATA40;
 }
 
-static unsigned int __devinit ata66_svwks (ide_hwif_t *hwif)
+static u8 __devinit ata66_svwks(ide_hwif_t *hwif)
 {
 	struct pci_dev *dev = hwif->pci_dev;
 
@@ -389,9 +389,9 @@
 	/* Per Specified Design by OEM, and ASIC Architect */
 	if ((dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE) ||
 	    (dev->device == PCI_DEVICE_ID_SERVERWORKS_CSB6IDE2))
-		return 1;
+		return ATA_CBL_PATA80;
 
-	return 0;
+	return ATA_CBL_PATA40;
 }
 
 static void __devinit init_hwif_svwks (ide_hwif_t *hwif)
@@ -422,8 +422,8 @@
 
 	hwif->ide_dma_check = &svwks_config_drive_xfer_rate;
 	if (hwif->pci_dev->device != PCI_DEVICE_ID_SERVERWORKS_OSB4IDE) {
-		if (!hwif->udma_four)
-			hwif->udma_four = ata66_svwks(hwif);
+		if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+			hwif->cbl = ata66_svwks(hwif);
 	}
 	if (!noautodma)
 		hwif->autodma = 1;