[PATCH 1/4] dmaengine: xilinx_dma: Add extended address support in CDMA

[Adrian Larumbe]

Not accounting for this means DMA HW descriptors can only be sourced from
the lower 32 bits of the address space. CDMA MSB descriptor registers were
also missing in the driver file, so this change also adds their register
offset definitions, which were taken from Xilpinx 'AXI Central Direct
Memory Access v4.1' LogiCORE IP Product Guide.

Signed-off-by: Adrian Larumbe <adrian.martinezlarumbe at imgtec.com>
---
 drivers/dma/xilinx/xilinx_dma.c | 29 ++++++++++++++++++++++++-----
 1 file changed, 24 insertions(+), 5 deletions(-)

diff --git a/drivers/dma/xilinx/xilinx_dma.c b/drivers/dma/xilinx/xilinx_dma.c
index 3aded7861fef..3f859de593dc 100644
--- a/drivers/dma/xilinx/xilinx_dma.c
+++ b/drivers/dma/xilinx/xilinx_dma.c
@@ -98,7 +98,9 @@
 #define XILINX_DMA_DMASR_FRAME_COUNT_MASK	GENMASK(23, 16)
 
 #define XILINX_DMA_REG_CURDESC			0x0008
+#define XILINX_DMA_REG_CURDESC_MSB		0x000C
 #define XILINX_DMA_REG_TAILDESC		0x0010
+#define XILINX_DMA_REG_TAILDESC_MSB	0x0014
 #define XILINX_DMA_REG_REG_INDEX		0x0014
 #define XILINX_DMA_REG_FRMSTORE		0x0018
 #define XILINX_DMA_REG_THRESHOLD		0x001c
@@ -184,6 +186,8 @@
 /* AXI CDMA Specific Registers/Offsets */
 #define XILINX_CDMA_REG_SRCADDR		0x18
 #define XILINX_CDMA_REG_DSTADDR		0x20
+#define XILINX_CDMA_REG_MSB_DSTADR	0x0024
+#define XILINX_CDMA_REG_MSB_SRCADDR	0x001C
 
 /* AXI CDMA Specific Masks */
 #define XILINX_CDMA_CR_SGMODE          BIT(3)
@@ -1459,9 +1463,19 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
 		dma_ctrl_set(chan, XILINX_DMA_REG_DMACR,
 			     XILINX_CDMA_CR_SGMODE);
 
+		if (chan->ext_addr) {
+			xilinx_write(chan, XILINX_DMA_REG_CURDESC_MSB,
+				     upper_32_bits(head_desc->async_tx.phys));
+		}
+
 		xilinx_write(chan, XILINX_DMA_REG_CURDESC,
 			     head_desc->async_tx.phys);
 
+		if (chan->ext_addr) {
+			xilinx_write(chan, XILINX_DMA_REG_TAILDESC_MSB,
+				     upper_32_bits(tail_segment->phys));
+		}
+
 		/* Update tail ptr register which will start the transfer */
 		xilinx_write(chan, XILINX_DMA_REG_TAILDESC,
 			     tail_segment->phys);
@@ -1476,11 +1490,16 @@ static void xilinx_cdma_start_transfer(struct xilinx_dma_chan *chan)
 
 		hw = &segment->hw;
 
-		xilinx_write(chan, XILINX_CDMA_REG_SRCADDR,
-			     xilinx_prep_dma_addr_t(hw->src_addr));
-		xilinx_write(chan, XILINX_CDMA_REG_DSTADDR,
-			     xilinx_prep_dma_addr_t(hw->dest_addr));
-
+		xilinx_write(chan, XILINX_CDMA_REG_SRCADDR, hw->src_addr);
+		xilinx_write(chan, XILINX_CDMA_REG_DSTADDR, hw->dest_addr);
+		if (chan->ext_addr) {
+			xilinx_write(chan,
+				     XILINX_CDMA_REG_MSB_SRCADDR,
+				     hw->src_addr_msb);
+			xilinx_write(chan,
+				     XILINX_CDMA_REG_MSB_DSTADR,
+				     hw->dest_addr_msb);
+		}
 		/* Start the transfer */
 		dma_ctrl_write(chan, XILINX_DMA_REG_BTT,
 				hw->control & chan->xdev->max_buffer_len);
-- 
2.17.1