dmaengine: at_xdmac: In at_xdmac_prep_dma_memset, treat value as a single byte

The value passed in to .prep_dma_memset is to be treated as a single
byte repeating pattern.
Signed-off-by: Ben Walker <benjamin.walker@intel.com>
Cc: Ludovic Desroches <ludovic.desroches@microchip.com>
Cc: Tudor Ambarus <tudor.ambarus@microchip.com>
Link: https://lore.kernel.org/r/20220301182551.883474-4-benjamin.walker@intel.comSigned-off-by: Vinod Koul <vkoul@kernel.org>

drivers/dma/at_xdmac.c

@@ -1202,6 +1202,7 @@ static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan,
 	unsigned long		flags;
 	size_t			ublen;
 	u32			dwidth;
+	char			pattern;
 	/*
 	 * WARNING: The channel configuration is set here since there is no
 	 * dmaengine_slave_config call in this case. Moreover we don't know the
@@ -1244,10 +1245,16 @@ static struct at_xdmac_desc *at_xdmac_memset_create_desc(struct dma_chan *chan,
 
 	chan_cc |= AT_XDMAC_CC_DWIDTH(dwidth);
 
+	/* Only the first byte of value is to be used according to dmaengine */
+	pattern = (char)value;
+
 	ublen = len >> dwidth;
 
 	desc->lld.mbr_da = dst_addr;
-	desc->lld.mbr_ds = value;
+	desc->lld.mbr_ds = (pattern << 24) |
+			   (pattern << 16) |
+			   (pattern << 8) |
+			   pattern;
 	desc->lld.mbr_ubc = AT_XDMAC_MBR_UBC_NDV3
 		| AT_XDMAC_MBR_UBC_NDEN
 		| AT_XDMAC_MBR_UBC_NSEN