dmaengine: mediatek: Add MediaTek High-Speed DMA controller for MT7622 and MT7623 SoC

MediaTek High-Speed DMA controller (HSDMA) on MT7622 and MT7623 SoC has
a single ring is dedicated to memory-to-memory transfer through ring based
descriptor management.

Even though there is only one physical ring available inside HSDMA, the
driver can be easily extended to the support of multiple virtual channels
processing simultaneously by means of DMA_VIRTUAL_CHANNELS effort.

Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/Kconfig

@@ -633,6 +633,8 @@ config ZX_DMA
 # driver files
 source "drivers/dma/bestcomm/Kconfig"
 
+source "drivers/dma/mediatek/Kconfig"
+
 source "drivers/dma/qcom/Kconfig"
 
 source "drivers/dma/dw/Kconfig"

drivers/dma/Makefile

@@ -75,5 +75,6 @@ obj-$(CONFIG_XGENE_DMA) += xgene-dma.o
 obj-$(CONFIG_ZX_DMA) += zx_dma.o
 obj-$(CONFIG_ST_FDMA) += st_fdma.o
 
+obj-y += mediatek/
 obj-y += qcom/
 obj-y += xilinx/

drivers/dma/mediatek/Kconfig

@@ -0,0 +1,13 @@
+
+config MTK_HSDMA
+	tristate "MediaTek High-Speed DMA controller support"
+	depends on ARCH_MEDIATEK || COMPILE_TEST
+	select DMA_ENGINE
+	select DMA_VIRTUAL_CHANNELS
+	---help---
+	  Enable support for High-Speed DMA controller on MediaTek
+	  SoCs.
+
+	  This controller provides the channels which is dedicated to
+	  memory-to-memory transfer to offload from CPU through ring-
+	  based descriptor management.

drivers/dma/mediatek/Makefile

@@ -0,0 +1 @@
+obj-$(CONFIG_MTK_HSDMA) += mtk-hsdma.o