ARM: OMAP4: Add local timer support for Device Tree

Add cortex-a9 local timer support for all OMAP4 based
SOCs using DT.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>

arch/arm/boot/dts/omap4.dtsi

@@ -45,6 +45,12 @@ L2: l2-cache-controller@48242000 {
 		cache-level = <2>;
 	};
 
+	local-timer@0x48240600 {
+		compatible = "arm,cortex-a9-twd-timer";
+		reg = <0x48240600 0x20>;
+		interrupts = <1 13 0x304>;
+	};
+
 	/*
 	 * The soc node represents the soc top level view. It is uses for IPs
 	 * that are not memory mapped in the MPU view or for the MPU itself.

arch/arm/mach-omap2/timer.c

@@ -36,6 +36,7 @@
 #include <linux/clocksource.h>
 #include <linux/clockchips.h>
 #include <linux/slab.h>
+#include <linux/of.h>
 
 #include <asm/mach/time.h>
 #include <plat/dmtimer.h>
@@ -386,6 +387,11 @@ static void __init omap4_timer_init(void)
 	if (omap_rev() != OMAP4430_REV_ES1_0) {
 		int err;
 
+		if (of_have_populated_dt()) {
+			twd_local_timer_of_register();
+			return;
+		}
+
 		err = twd_local_timer_register(&twd_local_timer);
 		if (err)
 			pr_err("twd_local_timer_register failed %d\n", err);