[PATCH 02/10] spi: dw-mid: always use duplex transfers when DMA

[Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>]

In case of DMA we never got things done until we enable both channels. In case
of receive only or send only mode the user has to provide a dummy buffer.

Signed-off-by: Andy Shevchenko <andriy.shevchenko-VuQAYsv1563Yd54FQh9/CA@public.gmane.org>
---
 drivers/spi/spi-dw-mid.c | 6 ++----
 drivers/spi/spi-dw.h     | 4 ++++
 2 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/drivers/spi/spi-dw-mid.c b/drivers/spi/spi-dw-mid.c
index f7f0ad2..97156e4 100644
--- a/drivers/spi/spi-dw-mid.c
+++ b/drivers/spi/spi-dw-mid.c
@@ -119,10 +119,8 @@ static int mid_spi_dma_transfer(struct dw_spi *dws, int cs_change)
 		spi_enable_chip(dws, 0);
 		dw_writew(dws, DW_SPI_DMARDLR, 0xf);
 		dw_writew(dws, DW_SPI_DMATDLR, 0x10);
-		if (dws->tx_dma)
-			dma_ctrl |= 0x2;
-		if (dws->rx_dma)
-			dma_ctrl |= 0x1;
+		dma_ctrl |= SPI_DMA_TDMAE;
+		dma_ctrl |= SPI_DMA_RDMAE;
 		dw_writew(dws, DW_SPI_DMACR, dma_ctrl);
 		spi_enable_chip(dws, 1);
 	}
diff --git a/drivers/spi/spi-dw.h b/drivers/spi/spi-dw.h
index 089fc4b..83a103a 100644
--- a/drivers/spi/spi-dw.h
+++ b/drivers/spi/spi-dw.h
@@ -74,6 +74,10 @@
 #define SPI_INT_RXFI			(1 << 4)
 #define SPI_INT_MSTI			(1 << 5)
 
+/* Bit fields in DMACR */
+#define SPI_DMA_RDMAE			(1 << 0)
+#define SPI_DMA_TDMAE			(1 << 1)
+
 /* TX RX interrupt level threshold, max can be 256 */
 #define SPI_INT_THRESHOLD		32
 
-- 
2.1.0

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