[PATCH 1/2] spi: renesas,rzv2m-csi: Add SPI Slave related properties

[Fabrizio Castro <fabrizio.castro.jz@renesas.com>]

The CSI IP found inside the Renesas RZ/V2M SoC can also work
in SPI slave mode.
When working in slave mode, the IP can make use of the SS
(Slave Select) pin, with "low" as default active level.
The active level of SS can be changed to "high" upon configuration.
This patch adds two new properties, one to make use of the
SS pin when in slave mode, and one to make the SS pin active high.

Signed-off-by: Fabrizio Castro <fabrizio.castro.jz@renesas.com>
---
 .../bindings/spi/renesas,rzv2m-csi.yaml           | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/Documentation/devicetree/bindings/spi/renesas,rzv2m-csi.yaml b/Documentation/devicetree/bindings/spi/renesas,rzv2m-csi.yaml
index e59183e53690..c3d8ad6525bb 100644
--- a/Documentation/devicetree/bindings/spi/renesas,rzv2m-csi.yaml
+++ b/Documentation/devicetree/bindings/spi/renesas,rzv2m-csi.yaml
@@ -39,6 +39,17 @@ properties:
   power-domains:
     maxItems: 1
 
+  renesas,csi-ss:
+    type: boolean
+    description:
+      Use CSI Slave Selection (SS) pin to enable transmission and reception when
+      in slave mode.
+
+  renesas,csi-ss-high:
+    type: boolean
+    description:
+      The SS pin is active high (by default the SS pin is active low).
+
 required:
   - compatible
   - reg
@@ -50,6 +61,10 @@ required:
   - '#address-cells'
   - '#size-cells'
 
+dependencies:
+  renesas,csi-ss: [ spi-slave ]
+  renesas,csi-ss-high: [ 'renesas,csi-ss' ]
+
 unevaluatedProperties: false
 
 examples:
-- 
2.34.1