diff options
| -rw-r--r-- | power/tegra.c | 20 |
1 files changed, 20 insertions, 0 deletions
diff --git a/power/tegra.c b/power/tegra.c index 28f3a892b5..b00ceb498e 100644 --- a/power/tegra.c +++ b/power/tegra.c @@ -81,6 +81,12 @@ */ #define PMIC_WARM_RESET_L_HOLD_TIME (4 * MSEC) +/* + * The first time the PMIC sees power (AC or battery) it needs 200ms (+/-12% + * oscillator tolerance) for the RTC startup. In addition there is a startup + * time of approx. 0.5msec until V2_5 regulator starts up. */ +#define PMIC_RTC_STARTUP (225 * MSEC) + /* Application processor power state */ static int ap_on; static int ap_suspended; @@ -453,10 +459,24 @@ static int check_for_power_on_event(void) */ static int power_on(void) { + uint64_t t; + /* Make sure we de-assert the PMI_THERM_L and AP_RESET_L pin. */ set_pmic_therm(0); set_ap_reset(0); + /* + * Before we push PMIC power button, wait for the PMI RTC ready, which + * takes PMIC_RTC_STARTUP from the AC/battery is plugged in. + */ + t = get_time().val; + if (t < PMIC_RTC_STARTUP) { + uint32_t wait = PMIC_RTC_STARTUP - t; + CPRINTF("[%T wait for %dms for PMIC RTC start-up]\n", + wait / MSEC); + usleep(wait); + } + /* Push the power button */ set_pmic_pwron(1); usleep(PMIC_PWRON_DEBOUNCE_TIME); |