irqchip: omap-intc: enable TURBO idle mode

When TURBO bit is set in the INTC_IDLE register,
the input synchronizer clock will be autogated
based on activity on the INTC.

Because this idle mode increases the interrupt
latency by 2 clock cycles, we're only enabling
it during suspend.
Acked-by: NJason Cooper <jason@lakedaemon.net>
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>

drivers/irqchip/irq-omap-intc.c

@@ -51,6 +51,9 @@
 #define INTCPS_NR_ILR_REGS	128
 #define INTCPS_NR_MIR_REGS	3
 
+#define INTC_IDLE_FUNCIDLE	(1 << 0)
+#define INTC_IDLE_TURBO		(1 << 1)
+
 #define INTC_PROTECTION_ENABLE	(1 << 0)
 
 /*
@@ -134,12 +137,14 @@ void omap3_intc_prepare_idle(void)
 	 * cf. errata ID i540 for 3430 (all revisions up to 3.1.x)
 	 */
 	intc_writel(INTC_SYSCONFIG, 0);
+	intc_writel(INTC_IDLE, INTC_IDLE_TURBO);
 }
 
 void omap3_intc_resume_idle(void)
 {
 	/* Re-enable autoidle */
 	intc_writel(INTC_SYSCONFIG, 1);
+	intc_writel(INTC_IDLE, 0);
 }
 
 /* XXX: FIQ and additional INTC support (only MPU at the moment) */