[PATCH 4.4 96/97] dmaengine: ti-dma-crossbar: Fix event mapping for TPCC_EVT_MUX_60_63

[Greg Kroah-Hartman]

4.4-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Vignesh R <vigneshr@xxxxxx>


[ Upstream commit d087f15786021a9605b20f4c678312510be4cac1 ]

Register layout of a typical TPCC_EVT_MUX_M_N register is such that the
lowest numbered event is at the lowest byte address and highest numbered
event at highest byte address. But TPCC_EVT_MUX_60_63 register layout is
different,  in that the lowest numbered event is at the highest address
and highest numbered event is at the lowest address. Therefore, modify
ti_am335x_xbar_write() to handle TPCC_EVT_MUX_60_63 register
accordingly.

Signed-off-by: Vignesh R <vigneshr@xxxxxx>
Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
Signed-off-by: Vinod Koul <vinod.koul@xxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/dma/ti-dma-crossbar.c |   10 +++++++++-
 1 file changed, 9 insertions(+), 1 deletion(-)

--- a/drivers/dma/ti-dma-crossbar.c
+++ b/drivers/dma/ti-dma-crossbar.c
@@ -51,7 +51,15 @@ struct ti_am335x_xbar_map {
 
 static inline void ti_am335x_xbar_write(void __iomem *iomem, int event, u8 val)
 {
-	writeb_relaxed(val, iomem + event);
+	/*
+	 * TPCC_EVT_MUX_60_63 register layout is different than the
+	 * rest, in the sense, that event 63 is mapped to lowest byte
+	 * and event 60 is mapped to highest, handle it separately.
+	 */
+	if (event >= 60 && event <= 63)
+		writeb_relaxed(val, iomem + (63 - event % 4));
+	else
+		writeb_relaxed(val, iomem + event);
 }
 
 static void ti_am335x_xbar_free(struct device *dev, void *route_data)