diff options
Diffstat (limited to 'drivers/timer/tsc_timer.c')
| -rw-r--r-- | drivers/timer/tsc_timer.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/drivers/timer/tsc_timer.c b/drivers/timer/tsc_timer.c index 747f190d38..6473de20f1 100644 --- a/drivers/timer/tsc_timer.c +++ b/drivers/timer/tsc_timer.c @@ -341,16 +341,12 @@ static int tsc_timer_get_count(struct udevice *dev, u64 *count) return 0; } -static void tsc_timer_ensure_setup(void) +static void tsc_timer_ensure_setup(bool stop) { if (gd->arch.tsc_base) return; gd->arch.tsc_base = rdtsc(); - /* - * If there is no clock frequency specified in the device tree, - * calibrate it by ourselves. - */ if (!gd->arch.clock_rate) { unsigned long fast_calibrate; @@ -366,7 +362,10 @@ static void tsc_timer_ensure_setup(void) if (fast_calibrate) goto done; - panic("TSC frequency is ZERO"); + if (stop) + panic("TSC frequency is ZERO"); + else + return; done: gd->arch.clock_rate = fast_calibrate * 1000000; @@ -377,11 +376,17 @@ static int tsc_timer_probe(struct udevice *dev) { struct timer_dev_priv *uc_priv = dev_get_uclass_priv(dev); - if (!uc_priv->clock_rate) { - tsc_timer_ensure_setup(); - uc_priv->clock_rate = gd->arch.clock_rate; + /* Try hardware calibration first */ + tsc_timer_ensure_setup(false); + if (!gd->arch.clock_rate) { + /* + * Use the clock frequency specified in the + * device tree as last resort + */ + if (!uc_priv->clock_rate) + panic("TSC frequency is ZERO"); } else { - gd->arch.tsc_base = rdtsc(); + uc_priv->clock_rate = gd->arch.clock_rate; } return 0; @@ -394,7 +399,7 @@ unsigned long notrace timer_early_get_rate(void) * clock rate can only be calibrated via some hardware ways. Specifying * it in the device tree won't work for the early timer. */ - tsc_timer_ensure_setup(); + tsc_timer_ensure_setup(true); return gd->arch.clock_rate; } |