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/cs5530.c b/drivers/ide/pci/cs5530.c
index 518f430..1588a32 100644
--- a/drivers/ide/pci/cs5530.c
+++ b/drivers/ide/pci/cs5530.c
@@ -71,19 +71,18 @@
 }
 
 /**
- *	cs5530_tuneproc		-	select/set PIO modes
+ *	cs5530_set_pio_mode	-	set PIO mode
+ *	@drive: drive
+ *	@pio: PIO mode number
  *
- *	cs5530_tuneproc() handles selection/setting of PIO modes
- *	for both the chipset and drive.
+ *	Handles setting of PIO mode for both the chipset and drive.
  *
- *	The ide_init_cs5530() routine guarantees that all drives
+ *	The init_hwif_cs5530() routine guarantees that all drives
  *	will have valid default PIO timings set up before we get here.
  */
 
-static void cs5530_tuneproc (ide_drive_t *drive, u8 pio)	/* pio=255 means "autotune" */
+static void cs5530_set_pio_mode(ide_drive_t *drive, const u8 pio)
 {
-	pio = ide_get_best_pio_mode(drive, pio, 4);
-
 	if (cs5530_set_xfer_mode(drive, XFER_PIO_0 + pio) == 0)
 		cs5530_tunepio(drive, pio);
 }
@@ -306,7 +305,7 @@
 	if (hwif->mate)
 		hwif->serialized = hwif->mate->serialized = 1;
 
-	hwif->tuneproc = &cs5530_tuneproc;
+	hwif->set_pio_mode = &cs5530_set_pio_mode;
 	hwif->speedproc = &cs5530_tune_chipset;
 
 	basereg = CS5530_BASEREG(hwif);