dma: sh_dma: not all SH DMAC implementations support MEMCPY

Add a flag to allow platforms to specify, whether a DMAC instance supports
the MEMCPY operation. To avoid regressions, preserve the current default.

Signed-off-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Acked-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>
diff --git a/drivers/dma/shdma.c b/drivers/dma/shdma.c
index 54043cd..812fd76 100644
--- a/drivers/dma/shdma.c
+++ b/drivers/dma/shdma.c
@@ -1262,7 +1262,8 @@
 
 	INIT_LIST_HEAD(&shdev->common.channels);
 
-	dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
+	if (!pdata->slave_only)
+		dma_cap_set(DMA_MEMCPY, shdev->common.cap_mask);
 	if (pdata->slave && pdata->slave_num)
 		dma_cap_set(DMA_SLAVE, shdev->common.cap_mask);
 
diff --git a/include/linux/sh_dma.h b/include/linux/sh_dma.h
index 8cd7fe5..425450b 100644
--- a/include/linux/sh_dma.h
+++ b/include/linux/sh_dma.h
@@ -70,6 +70,7 @@
 	unsigned int needs_tend_set:1;
 	unsigned int no_dmars:1;
 	unsigned int chclr_present:1;
+	unsigned int slave_only:1;
 };
 
 /* DMA register */