dmaengine: Add support for APM X-Gene SoC DMA engine driver

This patch implements the APM X-Gene SoC DMA engine driver. The APM X-Gene
SoC DMA engine consists of 4 DMA channels for performing DMA operations.
These DMA operations include memory copy, scatter-gather memory copy,
raid5 xor, and raid6 p+q offloading.
Signed-off-by: Rameshwar Prasad Sahu <rsahu@apm.com>
Signed-off-by: Loc Ho <lho@apm.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/Kconfig

@@ -435,6 +435,14 @@ config IMG_MDC_DMA
 	help
 	  Enable support for the IMG multi-threaded DMA controller (MDC).
 
+config XGENE_DMA
+	tristate "APM X-Gene DMA support"
+	select DMA_ENGINE
+	select DMA_ENGINE_RAID
+	select ASYNC_TX_ENABLE_CHANNEL_SWITCH
+	help
+	  Enable support for the APM X-Gene SoC DMA engine.
+
 config DMA_ENGINE
 	bool
 

drivers/dma/Makefile

@@ -52,3 +52,4 @@ obj-$(CONFIG_INTEL_MIC_X100_DMA) += mic_x100_dma.o
 obj-$(CONFIG_NBPFAXI_DMA) += nbpfaxi.o
 obj-$(CONFIG_DMA_SUN6I) += sun6i-dma.o
 obj-$(CONFIG_IMG_MDC_DMA) += img-mdc-dma.o
+obj-$(CONFIG_XGENE_DMA) += xgene-dma.o