diff options
| -rw-r--r-- | chip/g/idle.c | 85 |
1 files changed, 51 insertions, 34 deletions
diff --git a/chip/g/idle.c b/chip/g/idle.c index 3123bc14c7..4c7afe86b1 100644 --- a/chip/g/idle.c +++ b/chip/g/idle.c @@ -47,24 +47,12 @@ DECLARE_CONSOLE_COMMAND(idle, command_idle, "Set or show the idle action: wfi, sleep, deep sleep", NULL); -static void prepare_to_deep_sleep(void) +static void prepare_to_sleep(void) { /* No task switching! */ interrupt_disable(); /* - * Preserve some state prior to deep sleep. Pretty much all we need is - * the device address, since everything else can be reinitialized on - * resume. - */ - GREG32(PMU, PWRDN_SCRATCH18) = GR_USB_DCFG; - /* And the idle action */ - GREG32(PMU, PWRDN_SCRATCH17) = idle_action; - - /* Latch the pinmux values */ - GREG32(PINMUX, HOLD) = 1; - - /* * Specify the PINMUX pads that can wake us. * A1 is UART RX. Idle is high, so wake on low level * A12 is SPS_CS_L. Also wake on low. @@ -88,23 +76,51 @@ static void prepare_to_deep_sleep(void) GC_PMU_EXITPD_MASK_TIMELS0_PD_EXIT_TIMER0_MASK | GC_PMU_EXITPD_MASK_TIMELS0_PD_EXIT_TIMER1_MASK; - /* Clamp the USB pins and shut the PHY down. We have to do this in - * three separate steps, or Bad Things happen. */ - GWRITE_FIELD(USB, PCGCCTL, PWRCLMP, 1); - GWRITE_FIELD(USB, PCGCCTL, RSTPDWNMODULE, 1); - GWRITE_FIELD(USB, PCGCCTL, STOPPCLK, 1); - - /* Get ready... */ + /* Which rails should we turn off? */ GR_PMU_LOW_POWER_DIS = - /* The next "wfi" will trigger it */ - GC_PMU_LOW_POWER_DIS_START_MASK | - /* ... with these rails off */ - GC_PMU_LOW_POWER_DIS_VDDL_MASK | /* <= this means deep sleep */ GC_PMU_LOW_POWER_DIS_VDDIOF_MASK | GC_PMU_LOW_POWER_DIS_VDDXO_MASK | GC_PMU_LOW_POWER_DIS_JTR_RC_MASK; + + if (idle_action == IDLE_DEEP_SLEEP) { + /* + * Preserve some state prior to deep sleep. Pretty much all we + * need is the device address, since everything else can be + * reinitialized on resume. + */ + GREG32(PMU, PWRDN_SCRATCH18) = GR_USB_DCFG; + /* And the idle action */ + GREG32(PMU, PWRDN_SCRATCH17) = idle_action; + + /* Latch the pinmux values */ + GREG32(PINMUX, HOLD) = 1; + + /* Clamp the USB pins and shut the PHY down. We have to do this + * in three separate steps, or Bad Things happen. */ + GWRITE_FIELD(USB, PCGCCTL, PWRCLMP, 1); + GWRITE_FIELD(USB, PCGCCTL, RSTPDWNMODULE, 1); + GWRITE_FIELD(USB, PCGCCTL, STOPPCLK, 1); + + /* Shut down one more power rail for deep sleep */ + GR_PMU_LOW_POWER_DIS |= + GC_PMU_LOW_POWER_DIS_VDDL_MASK; + } + + /* The next "wfi" will trigger it */ + GR_PMU_LOW_POWER_DIS |= GC_PMU_LOW_POWER_DIS_START_MASK; } +/* This is for normal sleep only. Deep sleep resumes with a warm boot. */ +static void resume_from_sleep(void) +{ + /* Prevent accidental reentry */ + GR_PMU_LOW_POWER_DIS = 0; + + /* Allow task switching again */ + interrupt_enable(); +} + + /* The time in the future at which sleeping will be allowed. */ static timestamp_t next_sleep_time; @@ -146,23 +162,24 @@ void __idle(void) if (!sleep_delay_passed) timer_arm(next_sleep_time, TASK_ID_IDLE); - /* We're allowed to deep sleep, so set it up. */ + /* We're allowed to sleep now, so set it up. */ if (sleep_ok && sleep_delay_passed) - if (idle_action == IDLE_DEEP_SLEEP) - prepare_to_deep_sleep(); - /* Normal sleep is not yet implemented */ + if (idle_action != IDLE_WFI) + prepare_to_sleep(); /* Wait for the next irq event. This stops the CPU clock and * may trigger sleep or deep sleep if enabled. */ asm("wfi"); /* - * TODO: Normal sleep resumes by handling the interrupt, but we - * need to clear PMU_LOW_POWER_DIS right away or we might sleep - * again by accident. We can't do that here because we don't - * get here until the next idle, so we'll have to do it in the - * interrupt handler or when task switching. Deep sleep resumes - * with a warm boot, which handles it differently. + * Note: After resuming from normal sleep we should clear + * PMU_LOW_POWER_DIS to prevent sleeping again by accident. + * Normal sleep eventually resumes here after the waking + * interrupt has been handled, but since all the other tasks + * will get a chance to run first it might be some time before + * that happens. If we find ourselves going back into sleep + * unexpectedly, that might be why. */ + resume_from_sleep(); } } |