Documentation: devicetree: Update Exynos MCT bindings description

This patch updates description of device tree bindings for Exynos MCT
(multicore timers). Namely:
 - added note about simplified specification of local timer interrupts,
   when using single per-processor interrupt for all local timers,
 - changed first example that was incorrectly suggesting that global
   timer interrupts are optional,
 - simplified example interrupt map,
 - added example showing simplified local timer interrupt specification.

Signed-off-by: Tomasz Figa <t.figa@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Reviewed-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

1 files changed, 37 insertions, 17 deletions

diff --git a/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt
index b5a86d20ee36..167d5dab9f64 100644
--- a/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt
+++ b/Documentation/devicetree/bindings/timer/samsung,exynos4210-mct.txt
@@ -31,38 +31,58 @@ Required properties:
 	7: ..
 	i: Local Timer Interrupt n
 
-Example 1: In this example, the system uses only the first global timer
-	   interrupt generated by MCT and the remaining three global timer
-	   interrupts are unused. Two local timer interrupts have been
-	   specified.
+  For MCT block that uses a per-processor interrupt for local timers, such
+  as ones compatible with "samsung,exynos4412-mct", only one local timer
+  interrupt might be specified, meaning that all local timers use the same
+  per processor interrupt.
+
+Example 1: In this example, the IP contains two local timers, using separate
+	   interrupts, so two local timer interrupts have been specified,
+	   in addition to four global timer interrupts.
 
 	mct@10050000 {
 		compatible = "samsung,exynos4210-mct";
 		reg = <0x10050000 0x800>;
-		interrupts = <0 57 0>, <0 0 0>, <0 0 0>, <0 0 0>,
+		interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
 			     <0 42 0>, <0 48 0>;
 	};
 
-Example 2: In this example, the MCT global and local timer interrupts are
-	   connected to two separate interrupt controllers. Hence, an
-	   interrupt-map is created to map the interrupts to the respective
-	   interrupt controllers.
+Example 2: In this example, the timer interrupts are connected to two separate
+	   interrupt controllers. Hence, an interrupt-map is created to map
+	   the interrupts to the respective interrupt controllers.
 
 	mct@101C0000 {
 		compatible = "samsung,exynos4210-mct";
 		reg = <0x101C0000 0x800>;
-		interrupt-controller;
-		#interrups-cells = <2>;
 		interrupt-parent = <&mct_map>;
-		interrupts = <0 0>, <1 0>, <2 0>, <3 0>,
-			     <4 0>, <5 0>;
+		interrupts = <0>, <1>, <2>, <3>, <4>, <5>;
 
 		mct_map: mct-map {
-			#interrupt-cells = <2>;
+			#interrupt-cells = <1>;
 			#address-cells = <0>;
 			#size-cells = <0>;
-			interrupt-map = <0x0 0 &combiner 23 3>,
-					<0x4 0 &gic 0 120 0>,
-					<0x5 0 &gic 0 121 0>;
+			interrupt-map = <0 &gic 0 57 0>,
+					<1 &gic 0 69 0>,
+					<2 &combiner 12 6>,
+					<3 &combiner 12 7>,
+					<4 &gic 0 42 0>,
+					<5 &gic 0 48 0>;
 		};
 	};
+
+Example 3: In this example, the IP contains four local timers, but using
+	   a per-processor interrupt to handle them. Either all the local
+	   timer interrupts can be specified, with the same interrupt specifier
+	   value or just the first one.
+
+	mct@10050000 {
+		compatible = "samsung,exynos4412-mct";
+		reg = <0x10050000 0x800>;
+
+		/* Both ways are possible in this case. Either: */
+		interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
+			     <0 42 0>;
+		/* or: */
+		interrupts = <0 57 0>, <0 69 0>, <0 70 0>, <0 71 0>,
+			     <0 42 0>, <0 42 0>, <0 42 0>, <0 42 0>;
+	};