[PATCH] imx: syscounter: support timer_get_boot_us

[Jun Nie]

With supporting timer_get_boot_us, we can profile boot up time with below
configs and function bootstage_mark_name().

CONFIG_BOOTSTAGE=y
CONFIG_BOOTSTAGE_REPORT=y
CONFIG_CMD_BOOTSTAGE=y

Signed-off-by: Jun Nie <jun.nie at linaro.org>
---
 arch/arm/mach-imx/syscounter.c | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/arch/arm/mach-imx/syscounter.c b/arch/arm/mach-imx/syscounter.c
index 7c02e199a3..df478a2326 100644
--- a/arch/arm/mach-imx/syscounter.c
+++ b/arch/arm/mach-imx/syscounter.c
@@ -79,6 +79,7 @@ int timer_init(void)
 	gd->arch.tbl = 0;
 	gd->arch.tbu = 0;
 
+	gd->arch.timer_rate_hz = freq;
 	return 0;
 }
 #endif
@@ -100,6 +101,14 @@ ulong get_timer(ulong base)
 	return tick_to_time(get_ticks()) - base;
 }
 
+ulong timer_get_boot_us(void)
+{
+	if (!gd->arch.timer_rate_hz)
+		timer_init();
+
+	return tick_to_time(get_ticks());
+}
+
 void __udelay(unsigned long usec)
 {
 	unsigned long long tmp;
-- 
2.25.1