From:   Sander Vanheule <sander@svanheule.net>
To:     Thomas Gleixner <tglx@linutronix.de>,
        Marc Zyngier <maz@kernel.org>, devicetree@vger.kernel.org
Cc:     Rob Herring <robh+dt@kernel.org>,
        Birger Koblitz <mail@birger-koblitz.de>,
        Bert Vermeulen <bert@biot.com>,
        John Crispin <john@phrozen.org>, linux-kernel@vger.kernel.org,
        Sander Vanheule <sander@svanheule.net>
Subject: [RFC PATCH v1 3/4] dt-bindings: interrupt-controller: realtek,rtl-intc: replace irq mapping
Date:   Thu, 23 Dec 2021 13:08:33 +0100
Message-Id: <8a5931f18a6f1c92f8c8e4965dc65674d7e5a4c4.1640261161.git.sander@svanheule.net>
In-Reply-To: <cover.1640261161.git.sander@svanheule.net>
References: <cover.1640261161.git.sander@svanheule.net>
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The binding incorrectly specified the "interrupt-map" property should be
used, although the use is non-standard. A quirk had to be introduced in
commit de4adddcbcc2 ("of/irq: Add a quirk for controllers with their own
definition of interrupt-map") to allow the driver to function again.

Update the binding to require a list of parent interrupts instead, and
replace the "interrupt-map" property by the custom
"realtek,interrupt-routing" property.

Signed-off-by: Sander Vanheule <sander@svanheule.net>
---

The registers for this interrupt controller have 4 bits per SoC
interrupt. This means that, in theory, 15 output interrupts could be
wired up (a value of 0 means 'disconnected'), but we have only ever seen
this router being used to map to the six MIPS CPU hardware interrupts.
---
 .../realtek,rtl-intc.yaml                     | 49 +++++++++++++------
 1 file changed, 33 insertions(+), 16 deletions(-)

diff --git a/Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml b/Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml
index 9e76fff20323..4f7f30111a8e 100644
--- a/Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml
+++ b/Documentation/devicetree/bindings/interrupt-controller/realtek,rtl-intc.yaml
@@ -6,6 +6,11 @@ $schema: http://devicetree.org/meta-schemas/core.yaml#
 
 title: Realtek RTL SoC interrupt controller devicetree bindings
 
+description:
+  Interrupt router for Realtek MIPS SoCs, allowing up to 32 SoC interrupts to
+  be routed to one of up to 15 parent interrupts, or left disconnected. Most
+  commonly, the CPU's six hardware interrupts are used as parent interrupts.
+
 maintainers:
   - Birger Koblitz <mail@birger-koblitz.de>
   - Bert Vermeulen <bert@biot.com>
@@ -15,30 +20,40 @@ properties:
   compatible:
     const: realtek,rtl-intc
 
-  "#interrupt-cells":
-    const: 1
-
   reg:
     maxItems: 1
 
-  interrupts:
-    maxItems: 1
+  "#interrupt-cells":
+    const: 1
 
   interrupt-controller: true
 
-  "#address-cells":
-    const: 0
+  interrupts:
+    minItems: 1
+    maxItems: 15
+    description:
+      List of interrupts where SoC interrupts inputs can be routed to. Must be
+      provided in the same order as the output lines. The first interrupt is
+      thus selected via routing value 0, etc.
 
-  interrupt-map:
-    description: Describes mapping from SoC interrupts to CPU interrupts
+  realtek,interrupt-routing:
+    $ref: /schemas/types.yaml#/definitions/uint32-matrix
+    description:
+      List of <soc_int irq_idx> pairs, where "soc_int" is the interrupt line
+      number as provided by this controller. "irq_idx" is the index of the
+      interrupt in the list as specified the interrupts property.
+    items:
+      items:
+        - description: SoC interrupt index
+        - description: parent interrupt index
 
 required:
   - compatible
   - reg
   - "#interrupt-cells"
   - interrupt-controller
-  - "#address-cells"
-  - interrupt-map
+  - interrupts
+  - realtek,interrupt-routing
 
 additionalProperties: false
 
@@ -49,9 +64,11 @@ examples:
       #interrupt-cells = <1>;
       interrupt-controller;
       reg = <0x3000 0x20>;
-      #address-cells = <0>;
-      interrupt-map =
-              <31 &cpuintc 2>,
-              <30 &cpuintc 1>,
-              <29 &cpuintc 5>;
+
+      interrupt-parent = <&cpu_intc>;
+      interrupts = <2>, <3>, <4>;
+      realtek,interrupt-routing =
+              <31 0>, /* route to cpu_intc interrupt 2 */
+              <30 1>, /* route to cpu_intc interrupt 3 */
+              <29 2>; /* route to cpu_intc interrupt 4 */
     };
-- 
2.33.1