irqchip: st: Add documentation for STi based syscfg IRQs

Signed-off-by: Lee Jones <lee.jones@linaro.org>
Link: https://lkml.kernel.org/r/1424272444-16230-4-git-send-email-lee.jones@linaro.org
Signed-off-by: Jason Cooper <jason@lakedaemon.net>

diff --git a/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt b/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
new file mode 100644 (file)
index 0000000..ced6014
--- /dev/null
+++ b/Documentation/devicetree/bindings/interrupt-controller/st,sti-irq-syscfg.txt
@@ -0,0 +1,35 @@
+STMicroelectronics STi System Configuration Controlled IRQs
+-----------------------------------------------------------
+
+On STi based systems; External, CTI (Core Sight), PMU (Performance Management),
+and PL310 L2 Cache IRQs are controlled using System Configuration registers.
+This driver is used to unmask them prior to use.
+
+Required properties:
+- compatible   : Should be set to one of:
+                       "st,stih415-irq-syscfg"
+                       "st,stih416-irq-syscfg"
+                       "st,stih407-irq-syscfg"
+                       "st,stid127-irq-syscfg"
+- st,syscfg    : Phandle to Cortex-A9 IRQ system config registers
+- st,irq-device        : Array of IRQs to enable - should be 2 in length
+- st,fiq-device        : Array of FIQs to enable - should be 2 in length
+
+Optional properties:
+- st,invert-ext        : External IRQs can be inverted at will.  This property inverts
+                 these IRQs using bitwise logic.  A number of defines have been
+                 provided for convenience:
+                       ST_IRQ_SYSCFG_EXT_1_INV
+                       ST_IRQ_SYSCFG_EXT_2_INV
+                       ST_IRQ_SYSCFG_EXT_3_INV
+Example:
+
+irq-syscfg {
+       compatible    = "st,stih416-irq-syscfg";
+       st,syscfg     = <&syscfg_cpu>;
+       st,irq-device = <ST_IRQ_SYSCFG_PMU_0>,
+                       <ST_IRQ_SYSCFG_PMU_1>;
+       st,fiq-device = <ST_IRQ_SYSCFG_DISABLED>,
+                       <ST_IRQ_SYSCFG_DISABLED>;
+       st,invert-ext = <(ST_IRQ_SYSCFG_EXT_1_INV | ST_IRQ_SYSCFG_EXT_3_INV)>;
+};