Add support for RP2040 dormant (using external RTC clock)

src/rp2_common/pico_low_power/low_power.c

@@ -215,11 +215,7 @@ void low_power_sleep_until_pin_state(uint gpio_pin, bool edge, bool high,
 
     // Clear the irq so we can go back to dormant mode again if we want
     gpio_acknowledge_irq(gpio_pin, event);
-
-    // todo fix race in gpio_set_irq_enabled_with_callback
-    // gpio_set_irq_enabled_with_callback(gpio_pin, event, false, NULL);
-    gpio_set_irq_enabled(gpio_pin, event, false);
-    gpio_set_irq_callback(NULL);
+    gpio_set_irq_enabled_with_callback(gpio_pin, event, false, NULL);
 
     post_clock_gating();
 }
@@ -374,7 +370,7 @@ void low_power_go_dormant(dormant_clock_source_t dormant_clock_source) {
 
 int low_power_dormant_until_aon_timer(absolute_time_t until,
                                       dormant_clock_source_t dormant_clock_source,
-                                      __unused uint src_hz, uint gpio_pin,
+                                      uint src_hz, uint gpio_pin,
                                       const clock_dest_set_t *keep_enabled) {
     low_power_setup_clocks_for_dormant(dormant_clock_source);
 
@@ -388,6 +384,7 @@ int low_power_dormant_until_aon_timer(absolute_time_t until,
     clock_dest_set_add(&local_keep_enabled, CLK_DEST_RTC_RTC);
 #elif PICO_RP2350
     // todo
+    ((void)src_hz);
     ((void)gpio_pin);
     if (dormant_clock_source == DORMANT_CLOCK_SOURCE_LPOSC)
         powman_timer_set_1khz_tick_source_lposc();

test/hello_sleep/CMakeLists.txt

@@ -7,6 +7,17 @@ target_link_libraries(hello_sleep pico_stdlib pico_low_power pico_status_led)
 # create map/bin/hex file etc.
 pico_add_extra_outputs(hello_sleep)
 
+if (PICO_RP2040)
+        add_executable(rtc_clksrc
+                rtc_clksrc.c
+                )
+
+        target_link_libraries(rtc_clksrc pico_stdlib pico_status_led)
+
+        # create map/bin/hex file etc.
+        pico_add_extra_outputs(rtc_clksrc)
+endif()
+
 add_executable(hello_sleep_gpio
         hello_sleep_gpio.c
         )

test/hello_sleep/hello_sleep.c

@@ -14,6 +14,8 @@
 #define SLEEP_TIME_S 2
 #define SLEEP_TIME_MS SLEEP_TIME_S * 1000
 
+#define RTC_GPIO 22 // must support clock input, see the GPIO function table in the datasheet.
+
 bool repeater(repeating_timer_t *timer) {
     if (aon_timer_is_running()) {
         printf("  Repeating timer at %dms (aon: %dms)\n", to_ms_since_boot(get_absolute_time()), to_ms_since_boot(aon_timer_get_absolute_time()));
@@ -86,7 +88,6 @@ int main() {
     printf("Doing %d second pause to prove timer running\n", SLEEP_TIME_S);
     busy_wait_ms(SLEEP_TIME_MS);
 
-#if !PICO_RP2040
     printf("Going DORMANT for %d seconds via AON TIMER\n", SLEEP_TIME_S);
 
     // todo, ah; we should start the aon timer; still have to decide what to do about keeping them in sync
@@ -95,9 +96,13 @@ int main() {
     aon_timer_start(&ts);
 
     wakeup_time = delayed_by_ms(start_time, SLEEP_TIME_MS);
-    low_power_dormant_until_aon_timer(wakeup_time, DORMANT_CLOCK_SOURCE_LPOSC, XOSC_KHZ * 1000,
-                                      0, // gpio pin (unused with powman)
-                                      NULL);
+    low_power_dormant_until_aon_timer(wakeup_time,
+                                #if PICO_RP2040
+                                      DORMANT_CLOCK_SOURCE_XOSC, 46875,
+                                #else
+                                      DORMANT_CLOCK_SOURCE_LPOSC, XOSC_HZ,
+                                #endif
+                                      RTC_GPIO, NULL);
     diff = absolute_time_diff_us(get_absolute_time(), wakeup_time);
     // need to use the AON timer for checking time, since the other timer is unclocked
     diff = absolute_time_diff_us(wakeup_time, get_absolute_time());
@@ -113,6 +118,7 @@ int main() {
     printf("Doing %d second pause to prove timer running\n", SLEEP_TIME_S);
     busy_wait_ms(SLEEP_TIME_MS);
 
+#if !PICO_RP2040
     printf("Going to PSTATE for %d seconds\n", SLEEP_TIME_S);
 
     start_time = aon_timer_get_absolute_time();

test/hello_sleep/rtc_clksrc.c

@@ -0,0 +1,33 @@
+/**
+ * Copyright (c) 2020 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "pico/status_led.h"
+#include "pico/sync.h"
+#include "hardware/clocks.h"
+
+#define RTC_GPIO 21
+
+bool repeater(repeating_timer_t *timer) {
+    printf("  Repeating timer at %dms\n", to_ms_since_boot(get_absolute_time()));
+    status_led_set_state(!status_led_get_state());
+    return true;
+}
+
+int main() {
+    stdio_init_all();
+    status_led_init();
+
+    clock_gpio_init(RTC_GPIO, CLOCKS_CLK_GPOUT3_CTRL_AUXSRC_VALUE_CLK_RTC, 1);
+
+    repeating_timer_t repeat;
+    add_repeating_timer_ms(500, repeater, NULL, &repeat);
+
+    while (true) __wfi();
+
+    return 0;
+}