[PATCH 4.19.y-cip 3/7] spi: spi-mem: Add SPI_MEM_NO_DATA to the spi_mem_data_dir enum

Lad Prabhakar

From: Boris Brezillon <boris.brezillon@...>

commit 0ebb261a0b2d090de618a383d2378d4a00834958 upstream.

When defining spi_mem_op templates we don't necessarily know the size
that will be passed when the template is actually used, and basing the
supports_op() check on op->data.nbytes to know whether there will be
data transferred for a specific operation is this not possible.

Add SPI_MEM_NO_DATA to the spi_mem_data_dir enum so that we can base
our checks on op->data.dir instead of op->data.nbytes.

Signed-off-by: Boris Brezillon <boris.brezillon@...>
Reviewed-by: Miquel Raynal <miquel.raynal@...>
Signed-off-by: Mark Brown <broonie@...>
[PL: manually applied the changes]
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@...>
drivers/spi/spi-mem.c | 2 +-
include/linux/spi/spi-mem.h | 2 ++
2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/spi/spi-mem.c b/drivers/spi/spi-mem.c
index 62a7b80801d2..967f581bca4f 100644
--- a/drivers/spi/spi-mem.c
+++ b/drivers/spi/spi-mem.c
@@ -142,7 +142,7 @@ static bool spi_mem_default_supports_op(struct spi_mem *mem,
spi_check_buswidth_req(mem, op->dummy.buswidth, true))
return false;

- if (op->data.nbytes &&
+ if (op->data.dir != SPI_MEM_NO_DATA &&
spi_check_buswidth_req(mem, op->data.buswidth,
op->data.dir == SPI_MEM_DATA_OUT))
return false;
diff --git a/include/linux/spi/spi-mem.h b/include/linux/spi/spi-mem.h
index 69ee30456864..80db2de83402 100644
--- a/include/linux/spi/spi-mem.h
+++ b/include/linux/spi/spi-mem.h
@@ -57,10 +57,12 @@
* enum spi_mem_data_dir - describes the direction of a SPI memory data
* transfer from the controller perspective
+ * @SPI_MEM_NO_DATA: no data transferred
* @SPI_MEM_DATA_IN: data coming from the SPI memory
* @SPI_MEM_DATA_OUT: data sent the SPI memory
enum spi_mem_data_dir {

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