[PATCH v2] mtd: spi-nor: cadence-quadspi: Use proper enum for dma_unmap_single

[Nathan Chancellor <natechancellor@gmail.com>]

Clang warns when one enumerated type is converted implicitly to another.

drivers/mtd/spi-nor/cadence-quadspi.c:962:47: warning: implicit
conversion from enumeration type 'enum dma_transfer_direction' to
different enumeration type 'enum dma_data_direction' [-Wenum-conversion]
        dma_dst = dma_map_single(nor->dev, buf, len, DMA_DEV_TO_MEM);
                  ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
./include/linux/dma-mapping.h:428:66: note: expanded from macro
'dma_map_single'
#define dma_map_single(d, a, s, r) dma_map_single_attrs(d, a, s, r, 0)
                                   ~~~~~~~~~~~~~~~~~~~~          ^
drivers/mtd/spi-nor/cadence-quadspi.c:997:43: warning: implicit
conversion from enumeration type 'enum dma_transfer_direction' to
different enumeration type 'enum dma_data_direction' [-Wenum-conversion]
        dma_unmap_single(nor->dev, dma_dst, len, DMA_DEV_TO_MEM);
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~~~~~~~~~~~~~
./include/linux/dma-mapping.h:429:70: note: expanded from macro
'dma_unmap_single'
#define dma_unmap_single(d, a, s, r) dma_unmap_single_attrs(d, a, s, r, 0)
                                     ~~~~~~~~~~~~~~~~~~~~~~          ^
2 warnings generated.

Use the proper enums from dma_data_direction to satisfy Clang.

DMA_FROM_DEVICE = DMA_DEV_TO_MEM = 2

Link: https://github.com/ClangBuiltLinux/linux/issues/108
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---

v1 -> v2:

* Fix second half of patch (previously incorrectly used DMA_TO_DEVICE),
  thanks to Tudor Ambarus for catching this.

 drivers/mtd/spi-nor/cadence-quadspi.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/mtd/spi-nor/cadence-quadspi.c b/drivers/mtd/spi-nor/cadence-quadspi.c
index 8e714fbfa521..e24db817154e 100644
--- a/drivers/mtd/spi-nor/cadence-quadspi.c
+++ b/drivers/mtd/spi-nor/cadence-quadspi.c
@@ -959,7 +959,7 @@ static int cqspi_direct_read_execute(struct spi_nor *nor, u_char *buf,
 		return 0;
 	}
 
-	dma_dst = dma_map_single(nor->dev, buf, len, DMA_DEV_TO_MEM);
+	dma_dst = dma_map_single(nor->dev, buf, len, DMA_FROM_DEVICE);
 	if (dma_mapping_error(nor->dev, dma_dst)) {
 		dev_err(nor->dev, "dma mapping failed\n");
 		return -ENOMEM;
@@ -994,7 +994,7 @@ static int cqspi_direct_read_execute(struct spi_nor *nor, u_char *buf,
 	}
 
 err_unmap:
-	dma_unmap_single(nor->dev, dma_dst, len, DMA_DEV_TO_MEM);
+	dma_unmap_single(nor->dev, dma_dst, len, DMA_FROM_DEVICE);
 
 	return 0;
 }
-- 
2.19.0