dmaengine: shdma: Add more register documentation
Also add a few definitions that were missing.
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>
diff --git a/drivers/dma/sh/shdmac.c b/drivers/dma/sh/shdmac.c
index 146d5df..1a6f659 100644
--- a/drivers/dma/sh/shdmac.c
+++ b/drivers/dma/sh/shdmac.c
@@ -38,12 +38,12 @@
#include "../dmaengine.h"
#include "shdma.h"
-/* DMA register */
-#define SAR 0x00
-#define DAR 0x04
-#define TCR 0x08
-#define CHCR 0x0C
-#define DMAOR 0x40
+/* DMA registers */
+#define SAR 0x00 /* Source Address Register */
+#define DAR 0x04 /* Destination Address Register */
+#define TCR 0x08 /* Transfer Count Register */
+#define CHCR 0x0C /* Channel Control Register */
+#define DMAOR 0x40 /* DMA Operation Register */
#define TEND 0x18 /* USB-DMAC */