From: Biju Das <biju.das.jz@bp.renesas.com>

The CANFD on RZ/{G2L,G3E} and R-Car Gen4 support 3 modes FD-Only mode,
Classical CAN mode and CAN-FD mode. In FD-Only mode, communication in
Classical CAN frame format is disabled. Document renesas,fd-only to handle
this mode. As these SoCs support 3 modes, update the description of
renesas,no-can-fd property and disallow it for R-Car Gen3.

Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
---
v2->v3:
 * Added check to disallow the usage of both fd-only and no-can-fd.
v1->v2:
 * Added conditional check to disallow fd-only mode for R-Car Gen3.
---
 .../bindings/net/can/renesas,rcar-canfd.yaml  | 74 ++++++++++++++++++-
 1 file changed, 71 insertions(+), 3 deletions(-)

diff --git a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
index f4ac21c68427..a504f94d0a20 100644
--- a/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
+++ b/Documentation/devicetree/bindings/net/can/renesas,rcar-canfd.yaml
@@ -125,9 +125,17 @@ properties:
   renesas,no-can-fd:
     $ref: /schemas/types.yaml#/definitions/flag
     description:
-      The controller can operate in either CAN FD only mode (default) or
-      Classical CAN only mode.  The mode is global to all channels.
-      Specify this property to put the controller in Classical CAN only mode.
+      The controller can operate in either CAN-FD mode (default) or FD-Only
+      mode (RZ/{G2L,G3E} and R-Car Gen4) or Classical CAN mode. Specify this
+      property to put the controller in Classical CAN mode.
+
+  renesas,fd-only:
+    $ref: /schemas/types.yaml#/definitions/flag
+    description:
+      The CANFD on RZ/{G2L,G3E} and R-Car Gen4 SoCs support 3 modes FD-Only
+      mode, Classical CAN mode and CAN-FD mode (default). In FD-Only mode,
+      communication in Classical CAN frame format is disabled. Specify this
+      property to put the controller in FD-Only mode.
 
   assigned-clocks:
     description:
@@ -267,6 +275,30 @@ allOf:
       patternProperties:
         "^channel[6-7]$": false
 
+  - if:
+      properties:
+        compatible:
+          contains:
+            enum:
+              - renesas,rcar-gen3-canfd
+    then:
+      properties:
+        renesas,fd-only: false
+
+  - if:
+      required:
+        - renesas,no-can-fd
+    then:
+      properties:
+        renesas,fd-only: false
+
+  - if:
+      required:
+        - renesas,fd-only
+    then:
+      properties:
+        renesas,no-can-fd: false
+
 unevaluatedProperties: false
 
 examples:
@@ -297,3 +329,39 @@ examples:
             channel1 {
             };
     };
+
+  - |
+    #include <dt-bindings/interrupt-controller/arm-gic.h>
+    #include <dt-bindings/clock/r9a07g044-cpg.h>
+
+    canfd1: can@10050000 {
+            compatible = "renesas,r9a07g044-canfd", "renesas,rzg2l-canfd";
+            reg = <0x10050000 0x8000>;
+            interrupts = <GIC_SPI 426 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 427 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 422 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 424 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 428 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 423 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 425 IRQ_TYPE_LEVEL_HIGH>,
+                         <GIC_SPI 429 IRQ_TYPE_LEVEL_HIGH>;
+            interrupt-names = "g_err", "g_recc",
+                              "ch0_err", "ch0_rec", "ch0_trx",
+                              "ch1_err", "ch1_rec", "ch1_trx";
+            clocks = <&cpg CPG_MOD R9A07G044_CANFD_PCLK>, <&cpg CPG_CORE R9A07G044_CLK_P0_DIV2>, <&can_clk>;
+            clock-names = "fck", "canfd", "can_clk";
+            assigned-clocks = <&cpg CPG_CORE R9A07G044_CLK_P0_DIV2>;
+            assigned-clock-rates = <50000000>;
+            resets = <&cpg R9A07G044_CANFD_RSTP_N>, <&cpg R9A07G044_CANFD_RSTC_N>;
+            reset-names = "rstp_n", "rstc_n";
+            power-domains = <&cpg>;
+            renesas,no-can-fd;
+            renesas,fd-only;
+
+            channel0 {
+            };
+
+            channel1 {
+            };
+    };
+
-- 
2.43.0