ARM: ux500: Provide local timer support for Device Tree

This enables local timer (AKA: private timer) support for
all u8500 based hardware using DT.
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/boot/dts/db8500.dtsi

@@ -42,6 +42,12 @@ pmu {
 			interrupts = <0 7 0x4>;
 		};
 
+		timer@a0410600 {
+			compatible = "arm,cortex-a9-twd-timer";
+			reg = <0xa0410600 0x20>;
+			interrupts = <1 13 0x304>;
+		};
+
 		rtc@80154000 {
 			compatible = "stericsson,db8500-rtc";
 			reg = <0x80154000 0x1000>;

arch/arm/mach-ux500/timer.c

@@ -7,6 +7,7 @@
 #include <linux/io.h>
 #include <linux/errno.h>
 #include <linux/clksrc-dbx500-prcmu.h>
+#include <linux/of.h>
 
 #include <asm/smp_twd.h>
 
@@ -30,9 +31,13 @@ static void __init ux500_twd_init(void)
 	twd_local_timer = cpu_is_u5500() ? &u5500_twd_local_timer :
 					   &u8500_twd_local_timer;
 
-	err = twd_local_timer_register(twd_local_timer);
-	if (err)
-		pr_err("twd_local_timer_register failed %d\n", err);
+	if (of_have_populated_dt())
+		twd_local_timer_of_register();
+	else {
+		err = twd_local_timer_register(twd_local_timer);
+		if (err)
+			pr_err("twd_local_timer_register failed %d\n", err);
+	}
 }
 #else
 #define ux500_twd_init()	do { } while(0)