mxc: mx1/mx2 DMA: add a possibility to create an endless DMA transfer

[pandora-kernel.git] / arch / arm / plat-mxc / include / mach / dma-mx1-mx2.h

diff --git a/arch/arm/plat-mxc/include/mach/dma-mx1-mx2.h b/arch/arm/plat-mxc/include/mach/dma-mx1-mx2.h
index b3876cc..07be8ad 100644 (file)
--- a/arch/arm/plat-mxc/include/mach/dma-mx1-mx2.h
+++ b/arch/arm/plat-mxc/include/mach/dma-mx1-mx2.h
@@ -58,6 +58,14 @@ imx_dma_setup_single(int channel, dma_addr_t dma_address,
                unsigned int dma_length, unsigned int dev_addr,
                unsigned int dmamode);
 
+
+/*
+ * Use this flag as the dma_length argument to imx_dma_setup_sg()
+ * to create an endless running dma loop. The end of the scatterlist
+ * must be linked to the beginning for this to work.
+ */
+#define IMX_DMA_LENGTH_LOOP    ((unsigned int)-1)
+
 int
 imx_dma_setup_sg(int channel, struct scatterlist *sg,
                unsigned int sgcount, unsigned int dma_length,