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>

drivers/ide/pci/tc86c001.c

@@ -43,9 +43,8 @@ static int tc86c001_tune_chipset(ide_drive_t *drive, const u8 speed)
 	return ide_config_drive_speed(drive, speed);
 }
 
-static void tc86c001_tune_drive(ide_drive_t *drive, u8 pio)
+static void tc86c001_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
-	pio = ide_get_best_pio_mode(drive, pio, 4);
 	(void) tc86c001_tune_chipset(drive, XFER_PIO_0 + pio);
 }
 
@@ -171,7 +170,7 @@ static int tc86c001_config_drive_xfer_rate(ide_drive_t *drive)
 		return 0;
 
 	if (ide_use_fast_pio(drive))
-		tc86c001_tune_drive(drive, 255);
+		ide_set_max_pio(drive);
 
 	return -1;
 }
@@ -193,7 +192,7 @@ static void __devinit init_hwif_tc86c001(ide_hwif_t *hwif)
 	/* Store the system control register base for convenience... */
 	hwif->config_data = sc_base;
 
-	hwif->tuneproc	= &tc86c001_tune_drive;
+	hwif->set_pio_mode = &tc86c001_set_pio_mode;
 	hwif->speedproc = &tc86c001_tune_chipset;
 	hwif->busproc	= &tc86c001_busproc;