[v4 PATCH 09/12] spi/atmel_spi: correct 16 bits transfer with DMA

[Wenyou Yang]

From: Richard Genoud <richard.genoud at gmail.com>

Signed-off-by: Richard Genoud <richard.genoud at gmail.com>
Cc: grant.likely at secretlab.ca
Cc: spi-devel-general at lists.sourceforge.net
---
 drivers/spi/spi-atmel.c |   17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index a20cd03..8984563 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -452,12 +452,18 @@ static inline int atmel_spi_xfer_can_be_chained(struct spi_transfer *xfer)
 }
 
 static int atmel_spi_dma_slave_config(struct atmel_spi *as,
-				struct dma_slave_config *slave_config)
+				struct dma_slave_config *slave_config,
+				u8 bits_per_word)
 {
 	int err = 0;
 
-	slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
-	slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	if (bits_per_word > 8) {
+		slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+		slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+	} else {
+		slave_config->dst_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+		slave_config->src_addr_width = DMA_SLAVE_BUSWIDTH_1_BYTE;
+	}
 
 	slave_config->dst_addr = (dma_addr_t)as->phybase + SPI_TDR;
 	slave_config->src_addr = (dma_addr_t)as->phybase + SPI_RDR;
@@ -519,7 +525,7 @@ static int __devinit atmel_spi_configure_dma(struct atmel_spi *as)
 		goto error;
 	}
 
-	err = atmel_spi_dma_slave_config(as, &slave_config);
+	err = atmel_spi_dma_slave_config(as, &slave_config, 8);
 	if (err)
 		goto error;
 
@@ -653,10 +659,9 @@ static int atmel_spi_next_xfer_dma_submit(struct spi_master *master,
 
 	*plen = len;
 
-	if (atmel_spi_dma_slave_config(as, &slave_config))
+	if (atmel_spi_dma_slave_config(as, &slave_config, 8))
 		goto err_exit;
 
-
 	/* Send both scatterlists */
 	rxdesc = rxchan->device->device_prep_slave_sg(rxchan,
 					&as->dma.sgrx,
-- 
1.7.9.5