dma: at_hdmac: check direction properly for cyclic transfers

dma_transfer_direction is a normal enum. It means we can't usually use the
values as bit fields. Let's adjust this check and move it above the usage of
the direction parameter, due to the nature of the following usage of it.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/at_hdmac.c

@@ -778,16 +778,14 @@ atc_prep_slave_sg(struct dma_chan *chan, struct scatterlist *sgl,
  */
 static int
 atc_dma_cyclic_check_values(unsigned int reg_width, dma_addr_t buf_addr,
-		size_t period_len, enum dma_transfer_direction direction)
+		size_t period_len)
 {
 	if (period_len > (ATC_BTSIZE_MAX << reg_width))
 		goto err_out;
 	if (unlikely(period_len & ((1 << reg_width) - 1)))
 		goto err_out;
 	if (unlikely(buf_addr & ((1 << reg_width) - 1)))
 		goto err_out;
-	if (unlikely(!(direction & (DMA_DEV_TO_MEM | DMA_MEM_TO_DEV))))
-		goto err_out;
 
 	return 0;
 
@@ -886,14 +884,16 @@ atc_prep_dma_cyclic(struct dma_chan *chan, dma_addr_t buf_addr, size_t buf_len,
 		return NULL;
 	}
 
+	if (unlikely(!is_slave_direction(direction)))
+		goto err_out;
+
 	if (sconfig->direction == DMA_MEM_TO_DEV)
 		reg_width = convert_buswidth(sconfig->dst_addr_width);
 	else
 		reg_width = convert_buswidth(sconfig->src_addr_width);
 
 	/* Check for too big/unaligned periods and unaligned DMA buffer */
-	if (atc_dma_cyclic_check_values(reg_width, buf_addr,
-					period_len, direction))
+	if (atc_dma_cyclic_check_values(reg_width, buf_addr, period_len))
 		goto err_out;
 
 	/* build cyclic linked list */