and changed files

[powerpc.git] / drivers / ide / ide-dma.c

diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 08e7cd0..5fe8519 100644 (file)
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -705,6 +705,100 @@ int ide_use_dma(ide_drive_t *drive)
 
 EXPORT_SYMBOL_GPL(ide_use_dma);
 
+static const u8 xfer_mode_bases[] = {
+       XFER_UDMA_0,
+       XFER_MW_DMA_0,
+       XFER_SW_DMA_0,
+};
+
+static unsigned int ide_get_mode_mask(ide_drive_t *drive, u8 base)
+{
+       struct hd_driveid *id = drive->id;
+       ide_hwif_t *hwif = drive->hwif;
+       unsigned int mask = 0;
+
+       switch(base) {
+       case XFER_UDMA_0:
+               if ((id->field_valid & 4) == 0)
+                       break;
+
+               mask = id->dma_ultra & hwif->ultra_mask;
+
+               if (hwif->udma_filter)
+                       mask &= hwif->udma_filter(drive);
+
+               if ((mask & 0x78) && (eighty_ninty_three(drive) == 0))
+                       mask &= 0x07;
+               break;
+       case XFER_MW_DMA_0:
+               mask = id->dma_mword & hwif->mwdma_mask;
+               break;
+       case XFER_SW_DMA_0:
+               mask = id->dma_1word & hwif->swdma_mask;
+               break;
+       default:
+               BUG();
+               break;
+       }
+
+       return mask;
+}
+
+/**
+ *     ide_max_dma_mode        -       compute DMA speed
+ *     @drive: IDE device
+ *
+ *     Checks the drive capabilities and returns the speed to use
+ *     for the DMA transfer.  Returns 0 if the drive is incapable
+ *     of DMA transfers.
+ */
+
+u8 ide_max_dma_mode(ide_drive_t *drive)
+{
+       ide_hwif_t *hwif = drive->hwif;
+       unsigned int mask;
+       int x, i;
+       u8 mode = 0;
+
+       if (drive->media != ide_disk && hwif->atapi_dma == 0)
+               return 0;
+
+       for (i = 0; i < ARRAY_SIZE(xfer_mode_bases); i++) {
+               mask = ide_get_mode_mask(drive, xfer_mode_bases[i]);
+               x = fls(mask) - 1;
+               if (x >= 0) {
+                       mode = xfer_mode_bases[i] + x;
+                       break;
+               }
+       }
+
+       printk(KERN_DEBUG "%s: selected mode 0x%x\n", drive->name, mode);
+
+       return mode;
+}
+
+EXPORT_SYMBOL_GPL(ide_max_dma_mode);
+
+int ide_tune_dma(ide_drive_t *drive)
+{
+       u8 speed;
+
+       /* TODO: use only ide_max_dma_mode() */
+       if (!ide_use_dma(drive))
+               return 0;
+
+       speed = ide_max_dma_mode(drive);
+
+       if (!speed)
+               return 0;
+
+       drive->hwif->speedproc(drive, speed);
+
+       return ide_dma_enable(drive);
+}
+
+EXPORT_SYMBOL_GPL(ide_tune_dma);
+
 void ide_dma_verbose(ide_drive_t *drive)
 {
        struct hd_driveid *id   = drive->id;
@@ -767,7 +861,7 @@ int ide_set_dma(ide_drive_t *drive)
        switch(rc) {
        case -1: /* DMA needs to be disabled */
                hwif->dma_off_quietly(drive);
-               return 0;
+               return -1;
        case  0: /* DMA needs to be enabled */
                return hwif->ide_dma_on(drive);
        case  1: /* DMA setting cannot be changed */