The PolarFire SoC SPI "hard" controller supports eight CS lines, out of
which only one CS line is physically wired. The default value of
'num-cs' was never set and it did not didn't impose a maximum value.
To reflect this hardware limitation in the device tree, the binding
enforces that the 'num-cs' property cannot exceed 1 unless additional
CS lines are explicitly defined using GPIO descriptors.
Fixes: 2da187304e55 ("spi: add bindings for microchip mpfs spi")
Signed-off-by: Prajna Rajendra Kumar <prajna.rajendrakumar@xxxxxxxxxxxxx>
---
.../bindings/spi/microchip,mpfs-spi.yaml | 29 +++++++++++++++++--
1 file changed, 26 insertions(+), 3 deletions(-)
diff --git a/Documentation/devicetree/bindings/spi/microchip,mpfs-spi.yaml b/Documentation/devicetree/bindings/spi/microchip,mpfs-spi.yaml
index 74a817cc7d94..ffa8d1b48f8b 100644
--- a/Documentation/devicetree/bindings/spi/microchip,mpfs-spi.yaml
+++ b/Documentation/devicetree/bindings/spi/microchip,mpfs-spi.yaml
@@ -13,9 +13,6 @@ description:
maintainers:
- Conor Dooley <conor.dooley@xxxxxxxxxxxxx>
-allOf:
- - $ref: spi-controller.yaml#
-
properties:
compatible:
oneOf:
@@ -43,6 +40,32 @@ required:
- interrupts
- clocks
+allOf:
+ - $ref: spi-controller.yaml#
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: microchip,mpfs-spi
+ then:
+ properties:
+ num-cs:
+ default: 1
+
+ - if:
+ properties:
+ compatible:
+ contains:
+ const: microchip,mpfs-spi
+ not:
+ required:
+ - cs-gpios
+ then:
+ properties:
+ num-cs:
+ maximum: 1
+
unevaluatedProperties: false
examples:
--
2.25.1
