ide: add ide_set{_max}_pio() (take 4)

* Add IDE_HFLAG_ABUSE_{PREFETCH,FAST_DEVSEL,DMA_MODES} flags
  and set them in ht6560, cmd640, cmd64x and sc1200 host drivers.

* Add set_pio_mode_abuse() for checking if host driver has a non-standard
  ->tuneproc() implementation and use it in do_special().

* Add ide_set_pio() for setting PIO mode (it uses hwif->pio_mask to find
  the maximum PIO mode supported by the host), also add ide_set_max_pio()
  wrapper for ide_set_pio() to use for auto-tuning.  Convert users of
  ->tuneproc to use ide_set{_max}_pio() where possible.  This leaves only
  do_special(), set_using_pio(), ide_hwif_restore() and ide_set_pio() as
  a direct users of ->tuneproc.

* Remove no longer needed ide_get_best_pio_mode() calls and printk-s
  reporting PIO mode selected from ->tuneproc implementations.

* Rename ->tuneproc hook to ->set_pio_mode and make 'pio' argument const.

* Remove stale comment from ide_config_drive_speed().

v2:
* Fix "ata_" prefix (Noticed by Jeff).

v3:
* Minor cleanups/fixups per Sergei's suggestions.

v4:
* Fix compile problem in drivers/ide/pci/cmd640.c
  (Noticed by Andrew Morton).

* Improve some ->set_pio_mode comments.

Reviewed-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/sc1200.c b/drivers/ide/pci/sc1200.c
index 059071c..f9f5ed9 100644
--- a/drivers/ide/pci/sc1200.c
+++ b/drivers/ide/pci/sc1200.c
@@ -272,19 +272,20 @@
 }
 
 /*
- * sc1200_tuneproc() handles selection/setting of PIO modes
+ * sc1200_set_pio_mode() handles setting of PIO modes
  * for both the chipset and drive.
  *
  * All existing BIOSs for this chipset guarantee that all drives
  * will have valid default PIO timings set up before we get here.
  */
-static void sc1200_tuneproc (ide_drive_t *drive, byte pio)	/* mode=255 means "autotune" */
+
+static void sc1200_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
 	ide_hwif_t	*hwif = HWIF(drive);
 	int		mode = -1;
 
 	/*
-	 * bad abuse of ->tuneproc interface
+	 * bad abuse of ->set_pio_mode interface
 	 */
 	switch (pio) {
 		case 200: mode = XFER_UDMA_0;	break;
@@ -302,9 +303,6 @@
 		return;
 	}
 
-	pio = ide_get_best_pio_mode(drive, pio, 4);
-	printk("SC1200: %s: setting PIO mode%d\n", drive->name, pio);
-
 	if (sc1200_set_xfer_mode(drive, XFER_PIO_0 + pio) == 0)
 		sc1200_tunepio(drive, pio);
 }
@@ -420,7 +418,8 @@
 		hwif->ide_dma_end   = &sc1200_ide_dma_end;
         	if (!noautodma)
                 	hwif->autodma = 1;
-		hwif->tuneproc = &sc1200_tuneproc;
+
+		hwif->set_pio_mode = &sc1200_set_pio_mode;
 		hwif->speedproc = &sc1200_tune_chipset;
 	}
         hwif->atapi_dma = 1;
@@ -436,6 +435,7 @@
 	.init_hwif	= init_hwif_sc1200,
 	.autodma	= AUTODMA,
 	.bootable	= ON_BOARD,
+	.host_flags	= IDE_HFLAG_ABUSE_DMA_MODES,
 	.pio_mask	= ATA_PIO4,
 };