spi/dw_spi: clean the cs_control code

commit 052dc7c45i "spi/dw_spi: conditional transfer mode change"
introduced cs_control code, which has a bug by using bit offset
for spi mode to set transfer mode in control register. Also it
forces devices who don't need cs_control to re-configure the
control registers for each spi transfer. This patch will fix them

Signed-off-by: Feng Tang <feng.tang@intel.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

2 files changed, 7 insertions, 12 deletions

diff --git a/drivers/spi/dw_spi.c b/drivers/spi/dw_spi.c
index 11fbbf6fb07b..56247853c298 100644
--- a/drivers/spi/dw_spi.c
+++ b/drivers/spi/dw_spi.c
@@ -181,10 +181,6 @@ static void flush(struct dw_spi *dws)
         wait_till_not_busy(dws);
 }
 
-static void null_cs_control(u32 command)
-{
-}
-
 static int null_writer(struct dw_spi *dws)
 {
         u8 n_bytes = dws->n_bytes;
@@ -322,7 +318,7 @@ static void giveback(struct dw_spi *dws)
                                         struct spi_transfer,
                                         transfer_list);
 
-        if (!last_transfer->cs_change)
+        if (!last_transfer->cs_change && dws->cs_control)
                 dws->cs_control(MRST_SPI_DEASSERT);
 
         msg->state = NULL;
@@ -549,13 +545,13 @@ static void pump_transfers(unsigned long data)
          */
         if (dws->cs_control) {
                 if (dws->rx && dws->tx)
-                        chip->tmode = 0x00;
+                        chip->tmode = SPI_TMOD_TR;
                 else if (dws->rx)
-                        chip->tmode = 0x02;
+                        chip->tmode = SPI_TMOD_RO;
                 else
-                        chip->tmode = 0x01;
+                        chip->tmode = SPI_TMOD_TO;
 
-                cr0 &= ~(0x3 << SPI_MODE_OFFSET);
+                cr0 &= ~SPI_TMOD_MASK;
                 cr0 |= (chip->tmode << SPI_TMOD_OFFSET);
         }
 
@@ -704,9 +700,6 @@ static int dw_spi_setup(struct spi_device *spi)
                 chip = kzalloc(sizeof(struct chip_data), GFP_KERNEL);
                 if (!chip)
                         return -ENOMEM;
-
-                chip->cs_control = null_cs_control;
-                chip->enable_dma = 0;
         }
 
         /*
diff --git a/include/linux/spi/dw_spi.h b/include/linux/spi/dw_spi.h
index cc813f95a2f2..c91302f3a257 100644
--- a/include/linux/spi/dw_spi.h
+++ b/include/linux/spi/dw_spi.h
@@ -14,7 +14,9 @@
 #define SPI_MODE_OFFSET                 6
 #define SPI_SCPH_OFFSET                 6
 #define SPI_SCOL_OFFSET                 7
+
 #define SPI_TMOD_OFFSET                 8
+#define SPI_TMOD_MASK                   (0x3 << SPI_TMOD_OFFSET)
 #define SPI_TMOD_TR                     0x0             /* xmit & recv */
 #define SPI_TMOD_TO                     0x1             /* xmit only */
 #define SPI_TMOD_RO                     0x2             /* recv only */