Add RTC deep sleep alarm support

Author: hierophect

locale/circuitpython.pot

@@ -611,10 +611,6 @@ msgstr ""
 msgid "Can't set CCCD on local Characteristic"
 msgstr ""
 
-#: ports/raspberrypi/common-hal/alarm/time/TimeAlarm.c
-msgid "Cannot alarm from RTC in deep sleep"
-msgstr ""
-
 #: shared-bindings/storage/__init__.c shared-bindings/usb_cdc/__init__.c
 #: shared-bindings/usb_hid/__init__.c shared-bindings/usb_midi/__init__.c
 msgid "Cannot change USB devices now"

ports/raspberrypi/common-hal/alarm/SleepMemory.c

@@ -40,7 +40,7 @@ void alarm_sleep_memory_reset(void) {
 }
 
 uint32_t common_hal_alarm_sleep_memory_get_length(alarm_sleep_memory_obj_t *self) {
-    return 0;//sizeof(_sleep_mem);
+    return 0;// sizeof(_sleep_mem);
 }
 
 bool common_hal_alarm_sleep_memory_set_bytes(alarm_sleep_memory_obj_t *self, uint32_t start_index, const uint8_t *values, uint32_t len) {

ports/raspberrypi/common-hal/alarm/__init__.c

@@ -58,25 +58,31 @@
 // Not used elsewhere in the SDK for now, keep an eye on it
 #define RP_WKUP_SCRATCH_REG 0
 
-// Turn off nonvolatile Busio and other wake-only peripherals
+// Light sleep turns off nonvolatile Busio and other wake-only peripherals
 // TODO: this only saves about 2mA right now, expand with other non-essentials
 const uint32_t RP_LIGHTSLEEP_EN0_MASK = ~(
-    CLOCKS_SLEEP_EN0_CLK_SYS_SPI1_BITS &
-    CLOCKS_SLEEP_EN0_CLK_PERI_SPI1_BITS &
-    CLOCKS_SLEEP_EN0_CLK_SYS_SPI0_BITS &
-    CLOCKS_SLEEP_EN0_CLK_PERI_SPI0_BITS &
-    CLOCKS_SLEEP_EN0_CLK_SYS_PWM_BITS &
-    CLOCKS_SLEEP_EN0_CLK_SYS_PIO1_BITS &
-    CLOCKS_SLEEP_EN0_CLK_SYS_PIO0_BITS &
-    CLOCKS_SLEEP_EN0_CLK_SYS_I2C1_BITS &
-    CLOCKS_SLEEP_EN0_CLK_SYS_I2C0_BITS &
-    CLOCKS_SLEEP_EN0_CLK_SYS_ADC_BITS &
+    CLOCKS_SLEEP_EN0_CLK_SYS_SPI1_BITS |
+    CLOCKS_SLEEP_EN0_CLK_PERI_SPI1_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_SPI0_BITS |
+    CLOCKS_SLEEP_EN0_CLK_PERI_SPI0_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_PWM_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_PIO1_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_PIO0_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_I2C1_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_I2C0_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_ADC_BITS |
     CLOCKS_SLEEP_EN0_CLK_ADC_ADC_BITS
     );
-
 // This bank has the USB clocks in it, leave it for now
 const uint32_t RP_LIGHTSLEEP_EN1_MASK = CLOCKS_SLEEP_EN1_RESET;
 
+// Light sleeps used for TimeAlarm deep sleep turn off almost everything
+const uint32_t RP_LIGHTSLEEP_EN0_MASK_HARSH = (
+    CLOCKS_SLEEP_EN0_CLK_RTC_RTC_BITS |
+    CLOCKS_SLEEP_EN0_CLK_SYS_PADS_BITS
+    );
+const uint32_t RP_LIGHTSLEEP_EN1_MASK_HARSH = 0x0;
+
 STATIC void prepare_for_dormant_xosc(void);
 
 // Singleton instance of SleepMemory.
@@ -144,7 +150,6 @@ mp_obj_t common_hal_alarm_create_wake_alarm(void) {
 
 mp_obj_t common_hal_alarm_light_sleep_until_alarms(size_t n_alarms, const mp_obj_t *alarms) {
     _setup_sleep_alarms(false, n_alarms, alarms);
-    // alarm_pin_pinalarm_light_reset();
 
     mp_obj_t wake_alarm = mp_const_none;
 
@@ -173,7 +178,6 @@ mp_obj_t common_hal_alarm_light_sleep_until_alarms(size_t n_alarms, const mp_obj
         // Prune the clock for sleep
         clocks_hw->sleep_en0 &= RP_LIGHTSLEEP_EN0_MASK;
         clocks_hw->sleep_en1 = RP_LIGHTSLEEP_EN1_MASK;
-        // port_idle_until_interrupt();
 
         // Enable System Control Block (SCB) deep sleep
         uint save = scb_hw->scr;
@@ -195,8 +199,21 @@ void common_hal_alarm_set_deep_sleep_alarms(size_t n_alarms, const mp_obj_t *ala
 }
 
 void NORETURN common_hal_alarm_enter_deep_sleep(void) {
-    prepare_for_dormant_xosc();
-    xosc_dormant();
+    bool timealarm_set = alarm_time_timealarm_is_set();
+
+    // If there's a timealarm, just enter a very deep light sleep
+    if (timealarm_set) {
+        // Prune the clock for sleep
+        clocks_hw->sleep_en0 &= RP_LIGHTSLEEP_EN0_MASK_HARSH;
+        clocks_hw->sleep_en1 = RP_LIGHTSLEEP_EN1_MASK_HARSH;
+        // Enable System Control Block (SCB) deep sleep
+        uint save = scb_hw->scr;
+        scb_hw->scr = save | M0PLUS_SCR_SLEEPDEEP_BITS;
+        __wfi();
+    } else {
+        prepare_for_dormant_xosc();
+        xosc_dormant();
+    }
     // // TODO: support ROSC when available in SDK
     // rosc_set_dormant();
 

ports/raspberrypi/common-hal/alarm/pin/PinAlarm.c

@@ -38,6 +38,7 @@
 STATIC bool woke_up;
 STATIC uint64_t alarm_triggered_pins; // 36 actual pins
 STATIC uint64_t alarm_reserved_pins; // 36 actual pins
+STATIC bool _pinalarm_set = false;
 
 #define GPIO_IRQ_ALL_EVENTS 0x15u
 
@@ -152,6 +153,12 @@ void alarm_pin_pinalarm_set_alarms(bool deep_sleep, size_t n_alarms, const mp_ob
             if (deep_sleep) {
                 gpio_set_dormant_irq_enabled((uint)alarm->pin->number, event, true);
             }
+
+            _pinalarm_set = true;
         }
     }
 }
+
+bool alarm_pin_pinalarm_is_set(void) {
+    return _pinalarm_set;
+}

ports/raspberrypi/common-hal/alarm/pin/PinAlarm.h

@@ -42,3 +42,4 @@ void alarm_pin_pinalarm_reset(void);
 void alarm_pin_pinalarm_light_reset(void);
 void alarm_pin_pinalarm_set_alarms(bool deep_sleep, size_t n_alarms, const mp_obj_t *alarms);
 bool alarm_pin_pinalarm_woke_this_cycle(void);
+bool alarm_pin_pinalarm_is_set(void);

ports/raspberrypi/common-hal/alarm/time/TimeAlarm.c

@@ -35,6 +35,7 @@
 #include "hardware/rtc.h"
 
 STATIC bool woke_up = false;
+STATIC bool _timealarm_set = false;
 
 void timer_callback(void) {
     woke_up = true;
@@ -92,7 +93,7 @@ void alarm_time_timealarm_set_alarms(bool deep_sleep, size_t n_alarms, const mp_
         return;
     }
     if (deep_sleep) {
-        mp_raise_ValueError(translate("Cannot alarm from RTC in deep sleep"));
+        _timealarm_set = true;
     }
 
     // Compute how long to actually sleep, considering the time now.
@@ -123,3 +124,7 @@ void alarm_time_timealarm_set_alarms(bool deep_sleep, size_t n_alarms, const mp_
 
     woke_up = false;
 }
+
+bool alarm_time_timealarm_is_set(void) {
+    return _timealarm_set;
+}

ports/raspberrypi/common-hal/alarm/time/TimeAlarm.h

@@ -38,3 +38,4 @@ mp_obj_t alarm_time_timealarm_create_wakeup_alarm(void);
 void alarm_time_timealarm_reset(void);
 void alarm_time_timealarm_set_alarms(bool deep_sleep, size_t n_alarms, const mp_obj_t *alarms);
 bool alarm_time_timealarm_woke_this_cycle(void);
+bool alarm_time_timealarm_is_set(void);