[PATCH 06/20] Blackfin SPI Driver: unify duplicated code in dma read/write paths

From: Bryan Wu
Date: Fri Feb 06 2009 - 02:13:26 EST


From: Mike Frysinger <vapier.adi@xxxxxxxxx>

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@xxxxxxxxx>
Signed-off-by: Bryan Wu <cooloney@xxxxxxxxxx>
Acked-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
---
drivers/spi/spi_bfin5xx.c | 47 ++++++++++++++++++++------------------------
1 files changed, 21 insertions(+), 26 deletions(-)

diff --git a/drivers/spi/spi_bfin5xx.c b/drivers/spi/spi_bfin5xx.c
index 3945b59..acb9739 100644
--- 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");
--
1.5.6.3
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