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/jmicron.c b/drivers/ide/pci/jmicron.c
index 76ed251..a6008f6 100644
--- a/drivers/ide/pci/jmicron.c
+++ b/drivers/ide/pci/jmicron.c
@@ -25,10 +25,10 @@
  *	ata66_jmicron		-	Cable check
  *	@hwif: IDE port
  *
- *	Return 1 if the cable is 80pin
+ *	Returns the cable type.
  */
 
-static int __devinit ata66_jmicron(ide_hwif_t *hwif)
+static u8 __devinit ata66_jmicron(ide_hwif_t *hwif)
 {
 	struct pci_dev *pdev = hwif->pci_dev;
 
@@ -70,16 +70,17 @@
 	{
 	case PORT_PATA0:
 		if (control & (1 << 3))	/* 40/80 pin primary */
-			return 0;
-		return 1;
+			return ATA_CBL_PATA40;
+		return ATA_CBL_PATA80;
 	case PORT_PATA1:
 		if (control5 & (1 << 19))	/* 40/80 pin secondary */
-			return 0;
-		return 1;
+			return ATA_CBL_PATA40;
+		return ATA_CBL_PATA80;
 	case PORT_SATA:
 		break;
 	}
-	return 1; /* Avoid bogus "control reaches end of non-void function" */
+	/* Avoid bogus "control reaches end of non-void function" */
+	return ATA_CBL_PATA80;
 }
 
 static void jmicron_tuneproc (ide_drive_t *drive, byte mode_wanted)
@@ -159,8 +160,9 @@
 	hwif->mwdma_mask = 0x07;
 
 	hwif->ide_dma_check = &jmicron_config_drive_for_dma;
-	if (!(hwif->udma_four))
-		hwif->udma_four = ata66_jmicron(hwif);
+
+	if (hwif->cbl != ATA_CBL_PATA40_SHORT)
+		hwif->cbl = ata66_jmicron(hwif);
 
 	hwif->autodma = 1;
 	hwif->drives[0].autodma = hwif->autodma;