Blackfin SPI Driver: unify duplicated code in dma read/write paths

For DMA TX/RX operation in pump_transfers, DMA contriguration code in TX
and RX paths are almost the same.  This patch unify the duplicated DMA
code to make it more readable.

Signed-off-by: Mike Frysinger <vapier.adi@gmail.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Acked-by: David Brownell <dbrownell@users.sourceforge.net>
Cc: David Brownell <david-b@pacbell.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 2e0c024..4e45a3f 100644 (file)
--- a/drivers/spi/spi_bfin5xx.c
+++ b/drivers/spi/spi_bfin5xx.c
@@ -756,18 +756,19 @@ static void pump_transfers(unsigned long data)
        if (!full_duplex && drv_data->cur_chip->enable_dma
                                && drv_data->len > 6) {
 
+               unsigned long dma_start_addr;
+
                disable_dma(drv_data->dma_channel);
                clear_dma_irqstat(drv_data->dma_channel);
                bfin_spi_disable(drv_data);
 
                /* config dma channel */
                dev_dbg(&drv_data->pdev->dev, "doing dma transfer\n");
+               set_dma_x_count(drv_data->dma_channel, drv_data->len);
                if (width == CFG_SPI_WORDSIZE16) {
-                       set_dma_x_count(drv_data->dma_channel, drv_data->len);
                        set_dma_x_modify(drv_data->dma_channel, 2);
                        dma_width = WDSIZE_16;
                } else {
-                       set_dma_x_count(drv_data->dma_channel, drv_data->len);
                        set_dma_x_modify(drv_data->dma_channel, 1);
                        dma_width = WDSIZE_8;
                }
@@ -802,6 +803,7 @@ static void pump_transfers(unsigned long data)
                }
 
                /* In dma mode, rx or tx must be NULL in one transfer */
+               dma_config = (RESTART | dma_width | DI_EN);
                if (drv_data->rx != NULL) {
                        /* set transfer mode, and enable SPI */
                        dev_dbg(&drv_data->pdev->dev, "doing DMA in.\n");
@@ -815,19 +817,9 @@ static void pump_transfers(unsigned long data)
                        /* clear tx reg soformer data is not shifted out */
                        write_TDBR(drv_data, 0xFFFF);
 
-                       set_dma_x_count(drv_data->dma_channel, drv_data->len);
-
-                       /* start dma */
-                       dma_enable_irq(drv_data->dma_channel);
-                       dma_config = (WNR | RESTART | dma_width | DI_EN);
-                       set_dma_config(drv_data->dma_channel, dma_config);
-                       set_dma_start_addr(drv_data->dma_channel,
-                                       (unsigned long)drv_data->rx);
-                       enable_dma(drv_data->dma_channel);
-
-                       /* start SPI transfer */
-                       write_CTRL(drv_data,
-                               (cr | CFG_SPI_DMAREAD | BIT_CTL_ENABLE));
+                       dma_config |= WNR;
+                       dma_start_addr = (unsigned long)drv_data->rx;
+                       cr |= CFG_SPI_DMAREAD;
 
                } else if (drv_data->tx != NULL) {
                        dev_dbg(&drv_data->pdev->dev, "doing DMA out.\n");
@@ -838,18 +830,21 @@ static void pump_transfers(unsigned long data)
                                                (unsigned long) (drv_data->tx +
                                                drv_data->len_in_bytes));
 
-                       /* start dma */
-                       dma_enable_irq(drv_data->dma_channel);
-                       dma_config = (RESTART | dma_width | DI_EN);
-                       set_dma_config(drv_data->dma_channel, dma_config);
-                       set_dma_start_addr(drv_data->dma_channel,
-                                       (unsigned long)drv_data->tx);
-                       enable_dma(drv_data->dma_channel);
+                       dma_start_addr = (unsigned long)drv_data->tx;
+                       cr |= CFG_SPI_DMAWRITE;
+
+               } else
+                       BUG();
+
+               /* start dma */
+               dma_enable_irq(drv_data->dma_channel);
+               set_dma_config(drv_data->dma_channel, dma_config);
+               set_dma_start_addr(drv_data->dma_channel, dma_start_addr);
+               enable_dma(drv_data->dma_channel);
+
+               /* start SPI transfer */
+               write_CTRL(drv_data, (cr | BIT_CTL_ENABLE));
 
-                       /* start SPI transfer */
-                       write_CTRL(drv_data,
-                               (cr | CFG_SPI_DMAWRITE | BIT_CTL_ENABLE));
-               }
        } else {
                /* IO mode write then read */
                dev_dbg(&drv_data->pdev->dev, "doing IO transfer\n");