dma: add support for scatterlist to scatterlist copy

This adds support for scatterlist to scatterlist DMA transfers. A
similar interface is exposed by the fsldma driver (through the DMA_SLAVE
API) and by the ste_dma40 driver (through an exported function).

This patch paves the way for making this type of copy operation a part
of the generic DMAEngine API. Futher patches will add support in
individual drivers.

Signed-off-by: Ira W. Snyder <iws@ovro.caltech.edu>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/dma/dmaengine.c b/drivers/dma/dmaengine.c
index 9d31d5eb95c1..db403b8ccabd 100644
--- a/drivers/dma/dmaengine.c
+++ b/drivers/dma/dmaengine.c
@@ -690,6 +690,8 @@ int dma_async_device_register(struct dma_device *device)
                 !device->device_prep_dma_memset);
         BUG_ON(dma_has_cap(DMA_INTERRUPT, device->cap_mask) &&
                 !device->device_prep_dma_interrupt);
+        BUG_ON(dma_has_cap(DMA_SG, device->cap_mask) &&
+                !device->device_prep_dma_sg);
         BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&
                 !device->device_prep_slave_sg);
         BUG_ON(dma_has_cap(DMA_SLAVE, device->cap_mask) &&