[PATCH v5 3/3] spi: dt-bindings: document zero value for spi-{rx,tx}-bus-width properties

[Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>]

Following a change to the SPI framework, providing a value of zero for
'spi-rx-bus-width' and 'spi-tx-bus-width' is now possible and will
essentially mean that no RX or TX is allowed.

Reviewed-by: Rob Herring <robh@xxxxxxxxxx>
Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
---

Changelog v4 -> v5:
* https://lore.kernel.org/linux-spi/20201203140531.74470-3-alexandru.ardelean@xxxxxxxxxx/
* added 'Reviewed-by: Rob Herring <robh@xxxxxxxxxx>'

 Documentation/devicetree/bindings/spi/spi-controller.yaml | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/Documentation/devicetree/bindings/spi/spi-controller.yaml b/Documentation/devicetree/bindings/spi/spi-controller.yaml
index 5f505810104d..06786f1b43d2 100644
--- a/Documentation/devicetree/bindings/spi/spi-controller.yaml
+++ b/Documentation/devicetree/bindings/spi/spi-controller.yaml
@@ -152,8 +152,9 @@ patternProperties:
       spi-rx-bus-width:
         description:
           Bus width to the SPI bus used for read transfers.
+          If 0 is provided, then no RX will be possible on this device.
         $ref: /schemas/types.yaml#/definitions/uint32
-        enum: [1, 2, 4, 8]
+        enum: [0, 1, 2, 4, 8]
         default: 1
 
       spi-rx-delay-us:
@@ -163,8 +164,9 @@ patternProperties:
       spi-tx-bus-width:
         description:
           Bus width to the SPI bus used for write transfers.
+          If 0 is provided, then no TX will be possible on this device.
         $ref: /schemas/types.yaml#/definitions/uint32
-        enum: [1, 2, 4, 8]
+        enum: [0, 1, 2, 4, 8]
         default: 1
 
       spi-tx-delay-us:
-- 
2.17.1