dmaengine: Add flow controller information to dma_slave_config

Flow controller is programmable for few controllers and there are few
intelligent peripherals like, Synopsys JPEG controller, that needs to be a flow
controller of DMA transfers on dest side.

For this, currently two drivers, pl08x and dw_dmac, support flow controller to
be passed from platform to these drivers.

Perhaps, this should be a part of struct dma_slave_config. This patch adds
another field device_fc to this structure. User drivers must pass this as true
if they want to be flow controller of certain transfers.

Signed-off-by: Viresh Kumar <viresh.kumar@st.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Vinod Koul <vinod.koul@linux.intel.com>

include/linux/dmaengine.h

@@ -25,6 +25,7 @@
 #include <linux/uio.h>
 #include <linux/scatterlist.h>
 #include <linux/bitmap.h>
+#include <linux/types.h>
 #include <asm/page.h>
 
 /**
@@ -331,6 +332,9 @@ enum dma_slave_buswidth {
  * may or may not be applicable on memory sources.
  * @dst_maxburst: same as src_maxburst but for destination target
  * mutatis mutandis.
+ * @device_fc: Flow Controller Settings. Only valid for slave channels. Fill
+ * with 'true' if peripheral should be flow controller. Direction will be
+ * selected at Runtime.
  *
  * This struct is passed in as configuration data to a DMA engine
  * in order to set up a certain channel for DMA transport at runtime.
@@ -357,6 +361,7 @@ struct dma_slave_config {
 	enum dma_slave_buswidth dst_addr_width;
 	u32 src_maxburst;
 	u32 dst_maxburst;
+	bool device_fc;
 };
 
 static inline const char *dma_chan_name(struct dma_chan *chan)