ARM: mxc: Add dummy_get_cycles to avoid access before init is done

this is needed to use get_cycles with sched_clock. Accessing timer
without enabled clk will result in crash

Signed-off-by: Jan Weitzel <j.weitzel@phytec.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 8 insertions, 1 deletions

diff --git a/arch/arm/plat-mxc/time.c b/arch/arm/plat-mxc/time.c
index 9f0c2610595e..0142e4b2e12e 100644
--- a/arch/arm/plat-mxc/time.c
+++ b/arch/arm/plat-mxc/time.c
@@ -105,6 +105,11 @@ static void gpt_irq_acknowledge(void)
                 __raw_writel(V2_TSTAT_OF1, timer_base + V2_TSTAT);
 }
 
+static cycle_t dummy_get_cycles(struct clocksource *cs)
+{
+        return 0;
+}
+
 static cycle_t mx1_2_get_cycles(struct clocksource *cs)
 {
         return __raw_readl(timer_base + MX1_2_TCN);
@@ -118,7 +123,7 @@ static cycle_t v2_get_cycles(struct clocksource *cs)
 static struct clocksource clocksource_mxc = {
         .name           = "mxc_timer1",
         .rating         = 200,
-        .read           = mx1_2_get_cycles,
+        .read           = dummy_get_cycles,
         .mask           = CLOCKSOURCE_MASK(32),
         .flags          = CLOCK_SOURCE_IS_CONTINUOUS,
 };
@@ -129,6 +134,8 @@ static int __init mxc_clocksource_init(struct clk *timer_clk)
 
         if (timer_is_v2())
                 clocksource_mxc.read = v2_get_cycles;
+        else
+                clocksource_mxc.read = mx1_2_get_cycles;
 
         clocksource_register_hz(&clocksource_mxc, c);