irqchip: mips-gic: Implement irq_set_type callback

Implement an irq_set_type callback for the GIC which is used to set
the polarity and trigger type of GIC interrupts.

Signed-off-by: Andrew Bresticker <abrestic@chromium.org>
Acked-by: Jason Cooper <jason@lakedaemon.net>
Reviewed-by: Qais Yousef <qais.yousef@imgtec.com>
Tested-by: Qais Yousef <qais.yousef@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jeffrey Deans <jeffrey.deans@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: Jonas Gorski <jogo@openwrt.org>
Cc: John Crispin <blogic@openwrt.org>
Cc: David Daney <ddaney.cavm@gmail.com>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/7810/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/include/asm/gic.h b/arch/mips/include/asm/gic.h
index 1bf7985..662b567 100644
--- a/arch/mips/include/asm/gic.h
+++ b/arch/mips/include/asm/gic.h
@@ -23,6 +23,8 @@
 #define GIC_POL_NEG			0
 #define GIC_TRIG_EDGE			1
 #define GIC_TRIG_LEVEL			0
+#define GIC_TRIG_DUAL_ENABLE		1
+#define GIC_TRIG_DUAL_DISABLE		0
 
 #define MSK(n) ((1 << (n)) - 1)
 #define REG32(addr)		(*(volatile unsigned int *) (addr))
@@ -179,6 +181,13 @@
 		GIC_INTR_OFS(intr)), (1 << GIC_INTR_BIT(intr)), \
 		(trig) << GIC_INTR_BIT(intr))
 
+/* Dual edge triggering : Reset Value is always 0 */
+#define GIC_SH_SET_DUAL_OFS		0x0200
+#define GIC_SET_DUAL(intr, dual) \
+	GICBIS(GIC_REG_ADDR(SHARED, GIC_SH_SET_DUAL_OFS + \
+		GIC_INTR_OFS(intr)), (1 << GIC_INTR_BIT(intr)), \
+		(dual) << GIC_INTR_BIT(intr))
+
 /* Mask manipulation */
 #define GIC_SH_SMASK_OFS		0x0380
 #define GIC_SET_INTR_MASK(intr) \