From: Richard Genoud <richard.gen...@gmail.com>

Fix using PIO transfer mode only support 8 bits transfer, doesn't support 16 
bits.

Signed-off-by: Richard Genoud <richard.gen...@gmail.com>
Cc: spi-devel-general@lists.sourceforge.net
Cc: linux-ker...@vger.kernel.org
[wenyou.y...@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.y...@atmel.com>
---
 drivers/spi/spi-atmel.c |   47 ++++++++++++++++++++++++++++++++++++++---------
 1 file changed, 38 insertions(+), 9 deletions(-)

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 787bd2c..d8cb7da 100644
--- a/drivers/spi/spi-atmel.c
+++ b/drivers/spi/spi-atmel.c
@@ -526,13 +526,17 @@ static void atmel_spi_next_xfer_pio(struct spi_master 
*master,
        }
 
        if (xfer->tx_buf)
-               spi_writel(as, TDR, *(u8 *)(xfer->tx_buf));
+               if (xfer->bits_per_word > 8)
+                       spi_writel(as, TDR, *(u16 *)(xfer->tx_buf));
+               else
+                       spi_writel(as, TDR, *(u8 *)(xfer->tx_buf));
        else
                spi_writel(as, TDR, 0);
 
        dev_dbg(master->dev.parent,
-               "  start pio xfer %p: len %u tx %p rx %p\n",
-               xfer, xfer->len, xfer->tx_buf, xfer->rx_buf);
+               "  start pio xfer %p: len %u tx %p rx %p bitpw %d\n",
+               xfer, xfer->len, xfer->tx_buf, xfer->rx_buf,
+               xfer->bits_per_word);
 
        /* Enable relevant interrupts */
        spi_writel(as, IER, SPI_BIT(RDRF) | SPI_BIT(OVRES));
@@ -950,21 +954,39 @@ atmel_spi_pump_pio_data(struct atmel_spi *as, struct 
spi_transfer *xfer)
 {
        u8              *txp;
        u8              *rxp;
+       u16             *txp16;
+       u16             *rxp16;
        unsigned long   xfer_pos = xfer->len - as->current_remaining_bytes;
 
        if (xfer->rx_buf) {
-               rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
-               *rxp = spi_readl(as, RDR);
+               if (xfer->bits_per_word > 8) {
+                       rxp16 = (u16 *)(((u8 *)xfer->rx_buf) + xfer_pos);
+                       *rxp16 = spi_readl(as, RDR);
+               } else {
+                       rxp = ((u8 *)xfer->rx_buf) + xfer_pos;
+                       *rxp = spi_readl(as, RDR);
+               }
        } else {
                spi_readl(as, RDR);
        }
-
-       as->current_remaining_bytes--;
+       if (xfer->bits_per_word > 8) {
+               as->current_remaining_bytes -= 2;
+               if (as->current_remaining_bytes < 0)
+                       as->current_remaining_bytes = 0;
+       } else {
+               as->current_remaining_bytes--;
+       }
 
        if (as->current_remaining_bytes) {
                if (xfer->tx_buf) {
-                       txp = ((u8 *)xfer->tx_buf) + xfer_pos + 1;
-                       spi_writel(as, TDR, *txp);
+                       if (xfer->bits_per_word > 8) {
+                               txp16 = (u16 *)(((u8 *)xfer->tx_buf)
+                                                       + xfer_pos + 2);
+                               spi_writel(as, TDR, *txp16);
+                       } else {
+                               txp = ((u8 *)xfer->tx_buf) + xfer_pos + 1;
+                               spi_writel(as, TDR, *txp);
+                       }
                } else {
                        spi_writel(as, TDR, 0);
                }
@@ -1378,6 +1400,13 @@ static int atmel_spi_transfer(struct spi_device *spi, 
struct spi_message *msg)
                        }
                }
 
+               if (xfer->bits_per_word > 8) {
+                       if (xfer->len % 2) {
+                               dev_dbg(&spi->dev, "buffer len should be 16 
bits aligned\n");
+                               return -EINVAL;
+                       }
+               }
+
                /* FIXME implement these protocol options!! */
                if (xfer->speed_hz) {
                        dev_dbg(&spi->dev, "no protocol options yet\n");
-- 
1.7.9.5


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