nios2: check number of timer instances

Display error message if number of timers is less than 2.

Signed-off-by: Ley Foon Tan <lftan@altera.com>

1 files changed, 13 insertions, 2 deletions

diff --git a/arch/nios2/kernel/time.c b/arch/nios2/kernel/time.c
index 7f4547418ee1..bea8839d56d8 100644
--- a/arch/nios2/kernel/time.c
+++ b/arch/nios2/kernel/time.c
@@ -18,7 +18,9 @@
 #include <linux/io.h>
 #include <linux/slab.h>
 
-#define ALTERA_TIMER_STATUS_REG         0
+#define ALTR_TIMER_COMPATIBLE           "altr,timer-1.0"
+
+#define ALTERA_TIMER_STATUS_REG 0
 #define ALTERA_TIMER_CONTROL_REG        4
 #define ALTERA_TIMER_PERIODL_REG        8
 #define ALTERA_TIMER_PERIODH_REG        12
@@ -302,7 +304,16 @@ void read_persistent_clock(struct timespec *ts)
 
 void __init time_init(void)
 {
+        struct device_node *np;
+        int count = 0;
+
+        for_each_compatible_node(np, NULL,  ALTR_TIMER_COMPATIBLE)
+                count++;
+
+        if (count < 2)
+                panic("%d timer is found, it needs 2 timers in system\n", count);
+
         clocksource_of_init();
 }
 
-CLOCKSOURCE_OF_DECLARE(nios2_timer, "altr,timer-1.0", nios2_time_init);
+CLOCKSOURCE_OF_DECLARE(nios2_timer, ALTR_TIMER_COMPATIBLE, nios2_time_init);