blackfin: bf60x: pm: Add a debug option to calculate kernel wakeup time.

Display the total time when kernel resumes normal from standby or suspend to mem
mode.

Signed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bob Liu <lliubbo@gmail.com>

1 files changed, 30 insertions, 0 deletions

diff --git a/arch/blackfin/mach-common/pm.c b/arch/blackfin/mach-common/pm.c
index 610a3cdf3998..ca6655e0d653 100644
--- a/arch/blackfin/mach-common/pm.c
+++ b/arch/blackfin/mach-common/pm.c
@@ -247,9 +247,39 @@ static int bfin_pm_enter(suspend_state_t state)
         return 0;
 }
 
+#ifdef CONFIG_BFIN_PM_WAKEUP_TIME_BENCH
+void bfin_pm_end(void)
+{
+        u32 cycle, cycle2;
+        u64 usec64;
+        u32 usec;
+
+        __asm__ __volatile__ (
+                "1: %0 = CYCLES2\n"
+                "%1 = CYCLES\n"
+                "%2 = CYCLES2\n"
+                "CC = %2 == %0\n"
+                "if ! CC jump 1b\n"
+                : "=d,a" (cycle2), "=d,a" (cycle), "=d,a" (usec) : : "CC"
+        );
+
+        usec64 = ((u64)cycle2 << 32) + cycle;
+        do_div(usec64, get_cclk() / USEC_PER_SEC);
+        usec = usec64;
+        if (usec == 0)
+                usec = 1;
+
+        pr_info("PM: resume of kernel completes after  %ld msec %03ld usec\n",
+                usec / USEC_PER_MSEC, usec % USEC_PER_MSEC);
+}
+#endif
+
 static const struct platform_suspend_ops bfin_pm_ops = {
         .enter = bfin_pm_enter,
         .valid  = bfin_pm_valid,
+#ifdef CONFIG_BFIN_PM_WAKEUP_TIME_BENCH
+        .end = bfin_pm_end,
+#endif
 };
 
 static int __init bfin_pm_init(void)