spi/spi-atmel: BUG: fix doesn' support 16 bits transfers using PIO

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

Signed-off-by: Richard Genoud <richard.genoud@gmail.com>
[wenyou.yang@atmel.com: submit the patch]
Signed-off-by: Wenyou Yang <wenyou.yang@atmel.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 38 insertions, 9 deletions

diff --git a/drivers/spi/spi-atmel.c b/drivers/spi/spi-atmel.c
index 787bd2c22bca..d8cb7da65efe 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");