ide: add IDE_HFLAG_ABUSE_SET_DMA_MODE host flag

* Add IDE_HFLAG_ABUSE_SET_DMA_MODE host flag and use it to decide
  what to do with transfer modes < XFER_PIO_0 in ide_set_xfer_rate().

* Set IDE_HFLAG_ABUSE_SET_DMA_MODE in host drivers that need it
  (aec62xx, amd74xx, cs5520, cs5535, hpt34x, hpt366, pdc202xx_old,
  serverworks, tc86c001 and via82cxxx) and cleanup ->set_dma_mode
  methods in host drivers that don't (IDE core code guarantees that
  ->set_dma_mode will be called only for modes which are present
  in SWDMA/MWDMA/UDMA masks).

While at it:

* Add IDE_HFLAGS_HPT34X/HPT3XX/PDC202XX/SVWKS define in
  hpt34x/hpt366/pdc202xx_old/serverworks host driver.

There should be no functionality changes caused by this patch.

Acked-by: Sergei Shtylyov <sshtylyov@ru.mvista.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/pdc202xx_new.c b/drivers/ide/pci/pdc202xx_new.c
index 79ba8ef..ef4a99b 100644
--- a/drivers/ide/pci/pdc202xx_new.c
+++ b/drivers/ide/pci/pdc202xx_new.c
@@ -162,32 +162,18 @@
 	if (max_dma_rate(hwif->pci_dev) == 4) {
 		u8 mode = speed & 0x07;
 
-		switch (speed) {
-			case XFER_UDMA_6:
-			case XFER_UDMA_5:
-			case XFER_UDMA_4:
-			case XFER_UDMA_3:
-			case XFER_UDMA_2:
-			case XFER_UDMA_1:
-			case XFER_UDMA_0:
-				set_indexed_reg(hwif, 0x10 + adj,
-						udma_timings[mode].reg10);
-				set_indexed_reg(hwif, 0x11 + adj,
-						udma_timings[mode].reg11);
-				set_indexed_reg(hwif, 0x12 + adj,
-						udma_timings[mode].reg12);
-				break;
-			case XFER_MW_DMA_2:
-			case XFER_MW_DMA_1:
-			case XFER_MW_DMA_0:
-				set_indexed_reg(hwif, 0x0e + adj,
-						mwdma_timings[mode].reg0e);
-				set_indexed_reg(hwif, 0x0f + adj,
-						mwdma_timings[mode].reg0f);
-				break;
-			default:
-				printk(KERN_ERR "pdc202xx_new: "
-				       "Unknown speed %d ignored\n", speed);
+		if (speed >= XFER_UDMA_0) {
+			set_indexed_reg(hwif, 0x10 + adj,
+					udma_timings[mode].reg10);
+			set_indexed_reg(hwif, 0x11 + adj,
+					udma_timings[mode].reg11);
+			set_indexed_reg(hwif, 0x12 + adj,
+					udma_timings[mode].reg12);
+		} else {
+			set_indexed_reg(hwif, 0x0e + adj,
+					mwdma_timings[mode].reg0e);
+			set_indexed_reg(hwif, 0x0f + adj,
+					mwdma_timings[mode].reg0f);
 		}
 	} else if (speed == XFER_UDMA_2) {
 		/* Set tHOLD bit to 0 if using UDMA mode 2 */