[nrf fromtree] dts: bindings: mspi-controller: Add "packet-data-limit" property

Add a property with which MSPI controllers can indicate their limits
on the maximum amount of data they can transfer in one packet.
Use the property for the SSI controller, for which the clock stretching
feature requires the use of the NDF field of the CTRLR1 register, which
is 16-bit wide, hence the data length limit is 64 kB.

Signed-off-by: Andrzej Głąbek <[email protected]>
(cherry picked from commit b42a33d)

Author: anangl

dts/bindings/mspi/mspi-controller.yaml

@@ -92,3 +92,11 @@ properties:
       Regardless of whether the CE pin may need software control or MSPI
       controller has dedicated CE pin, this field should be defined to
       help manage multiple devices on the same MSPI controller.
+
+  packet-data-limit:
+    type: int
+    description: |
+      Specifies the maximum length of data that the controller can transfer
+      in a single packet. Transceive requests made to the controller must be
+      split into multiple packets if a single one would exceed this value.
+      If not specified, no limit is imposed.

dts/bindings/mspi/snps,designware-ssi.yaml

@@ -14,6 +14,10 @@ properties:
   interrupts:
     required: true
 
+  packet-data-limit:
+    required: true
+    const: 65536
+
   aux-reg-enable:
     type: boolean
     description: |

dts/vendor/nordic/nrf54h20.dtsi

@@ -649,6 +649,7 @@
 				interrupts = <149 NRF_DEFAULT_IRQ_PRIORITY>;
 				power-domains = <&gdpwr_fast_active_0>;
 				clock-frequency = <DT_FREQ_M(400)>;
+				packet-data-limit = <65536>;
 				fifo-depth = <32>;
 				status = "disabled";
 			};

dts/vendor/nordic/nrf9280.dtsi

@@ -384,6 +384,7 @@
 				reg-names = "wrapper", "core";
 				interrupts = <149 NRF_DEFAULT_IRQ_PRIORITY>;
 				clock-frequency = <DT_FREQ_M(400)>;
+				packet-data-limit = <65536>;
 				fifo-depth = <32>;
 				status = "disabled";
 			};