dt-bindings: interrupt-controller: Add Aspeed SCU interrupt controller

Document the Aspeed SCU interrupt controller and add an include file
for the interrupts it provides.
Signed-off-by: Eddie James <eajames@linux.ibm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Acked-by: Andrew Jeffery <andrew@aj.id.au>
Link: https://lore.kernel.org/r/1579123790-6894-2-git-send-email-eajames@linux.ibm.com

Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt

+Aspeed AST25XX and AST26XX SCU Interrupt Controller
+
+Required Properties:
+ - #interrupt-cells		: must be 1
+ - compatible			: must be "aspeed,ast2500-scu-ic",
+				  "aspeed,ast2600-scu-ic0" or
+				  "aspeed,ast2600-scu-ic1"
+ - interrupts			: interrupt from the parent controller
+ - interrupt-controller		: indicates that the controller receives and
+				  fires new interrupts for child busses
+
+Example:
+
+    syscon@1e6e2000 {
+        ranges = <0 0x1e6e2000 0x1a8>;
+
+        scu_ic: interrupt-controller@18 {
+            #interrupt-cells = <1>;
+            compatible = "aspeed,ast2500-scu-ic";
+            interrupts = <21>;
+            interrupt-controller;
+        };
+    };

MAINTAINERS

@@ -2692,6 +2692,13 @@ S:	Maintained
 F:	drivers/pinctrl/aspeed/
 F:	Documentation/devicetree/bindings/pinctrl/aspeed,*
 
+ASPEED SCU INTERRUPT CONTROLLER DRIVER
+M:	Eddie James <eajames@linux.ibm.com>
+L:	linux-aspeed@lists.ozlabs.org (moderated for non-subscribers)
+S:	Maintained
+F:	Documentation/devicetree/bindings/interrupt-controller/aspeed,ast2xxx-scu-ic.txt
+F:	include/dt-bindings/interrupt-controller/aspeed-scu-ic.h
+
 ASPEED VIDEO ENGINE DRIVER
 M:	Eddie James <eajames@linux.ibm.com>
 L:	linux-media@vger.kernel.org

include/dt-bindings/interrupt-controller/aspeed-scu-ic.h

+/* SPDX-License-Identifier: GPL-2.0+ */
+
+#ifndef _DT_BINDINGS_INTERRUPT_CONTROLLER_ASPEED_SCU_IC_H_
+#define _DT_BINDINGS_INTERRUPT_CONTROLLER_ASPEED_SCU_IC_H_
+
+#define ASPEED_SCU_IC_VGA_CURSOR_CHANGE			0
+#define ASPEED_SCU_IC_VGA_SCRATCH_REG_CHANGE		1
+
+#define ASPEED_AST2500_SCU_IC_PCIE_RESET_LO_TO_HI	2
+#define ASPEED_AST2500_SCU_IC_PCIE_RESET_HI_TO_LO	3
+#define ASPEED_AST2500_SCU_IC_LPC_RESET_LO_TO_HI	4
+#define ASPEED_AST2500_SCU_IC_LPC_RESET_HI_TO_LO	5
+#define ASPEED_AST2500_SCU_IC_ISSUE_MSI			6
+
+#define ASPEED_AST2600_SCU_IC0_PCIE_PERST_LO_TO_HI	2
+#define ASPEED_AST2600_SCU_IC0_PCIE_PERST_HI_TO_LO	3
+#define ASPEED_AST2600_SCU_IC0_PCIE_RCRST_LO_TO_HI	4
+#define ASPEED_AST2600_SCU_IC0_PCIE_RCRST_HI_TO_LO	5
+
+#define ASPEED_AST2600_SCU_IC1_LPC_RESET_LO_TO_HI	0
+#define ASPEED_AST2600_SCU_IC1_LPC_RESET_HI_TO_LO	1
+
+#endif /* _DT_BINDINGS_INTERRUPT_CONTROLLER_ASPEED_SCU_IC_H_ */