Add a couple of simple powman examples

powman_timer: Repeatedly switches the device off for 5s
powman_gpio: Repeatedly switches the device off until a GPIO goes high

Author: peterharperuk

CMakeLists.txt

@@ -75,6 +75,7 @@ add_subdirectory(otp)
 add_subdirectory(picoboard)
 add_subdirectory(pico_w)
 add_subdirectory(pio)
+add_subdirectory(powman)
 add_subdirectory(pwm)
 add_subdirectory(reset)
 add_subdirectory(rtc)

README.md

@@ -294,6 +294,13 @@ App|Description
 [ws2812](pio/ws2812) | Examples of driving WS2812 addressable RGB LEDs.
 [addition](pio/addition) | Add two integers together using PIO. Only around 8 billion times slower than Cortex-M0+.
 
+### POWMAN
+
+App|Description
+---|---
+[powman_timer](powman/powman_timer) | Example demonstrating how to turn the device off and back on at a certain time
+[powman_gpio](powman/powman_gpio) | Example demonstrating how to turn the device off and back on when a GPIO goes high
+
 ### PWM
 
 App|Description

powman/CMakeLists.txt

@@ -0,0 +1,14 @@
+add_library(powman_example INTERFACE)
+target_sources(powman_example INTERFACE
+    ${CMAKE_CURRENT_LIST_DIR}/powman_example.c
+)
+target_include_directories(powman_example INTERFACE
+    ${CMAKE_CURRENT_LIST_DIR}
+)
+target_link_libraries(powman_example INTERFACE
+    hardware_powman
+    hardware_gpio
+)
+
+add_subdirectory(powman_timer)
+add_subdirectory(powman_gpio)

powman/powman_example.c

@@ -0,0 +1,88 @@
+#include <stdio.h>
+#include <inttypes.h>
+
+#include "pico/stdio.h"
+#include "pico/sync.h"
+#include "hardware/gpio.h"
+#include "hardware/powman.h"
+#include "powman_example.h"
+
+static powman_power_state off_state;
+static powman_power_state on_state;
+
+// Initialise everything
+void powman_example_init(uint64_t abs_time_ms) {
+    // start powman and set the time
+    powman_timer_start();
+    powman_timer_set_ms(abs_time_ms);
+
+    // Allow power down when debugger connected
+    powman_set_debug_power_request_ignored(true);
+
+    // Power states
+    powman_power_state P1_7 = POWMAN_POWER_STATE_NONE;
+
+    powman_power_state P0_3 = POWMAN_POWER_STATE_NONE;
+    P0_3 = powman_power_state_with_domain_on(P0_3, POWMAN_POWER_DOMAIN_SWITCHED_CORE);
+    P0_3 = powman_power_state_with_domain_on(P0_3, POWMAN_POWER_DOMAIN_XIP_CACHE);
+
+    off_state = P1_7;
+    on_state = P0_3;
+}
+
+// Initiate power off
+static int powman_example_off(void) {
+    // Get ready to power off
+    stdio_flush();
+
+    // Set power states
+    bool valid_state = powman_configure_wakeup_state(off_state, on_state);
+    if (!valid_state) {
+        return PICO_ERROR_INVALID_STATE;
+    }
+
+    // reboot to main
+    powman_hw->boot[0] = 0;
+    powman_hw->boot[1] = 0;
+    powman_hw->boot[2] = 0;
+    powman_hw->boot[3] = 0;
+
+    // Switch to required power state
+    int rc = powman_set_power_state(off_state);
+    if (rc != PICO_OK) {
+        return rc;
+    }
+
+    // Power down
+    while (true) __wfi();
+}
+
+// Power off until a gpio goes high
+int powman_example_off_until_gpio_high(int gpio) {
+    gpio_init(gpio);
+    gpio_set_dir(gpio, false);
+    if (gpio_get(gpio)) {
+        printf("Waiting for gpio %d to go low\n", gpio);
+        while(gpio_get(gpio)) {
+            sleep_ms(100);
+        }
+    }
+    printf("Powering off until GPIO %d goes high\n", gpio);
+    powman_enable_gpio_wakeup(0, gpio, false, true);
+    return powman_example_off();
+}
+
+// Power off until an absolute time
+int powman_example_off_until_time(uint64_t abs_time_ms) {
+    // Start powman timer and turn off
+    printf("Powering off for %"PRIu64"ms\n", powman_timer_get_ms() - abs_time_ms);
+    powman_enable_alarm_wakeup_at_ms(abs_time_ms);
+    return powman_example_off();
+}
+
+// Power off for a number of milliseconds
+int powman_example_off_for_ms(uint64_t duration_ms) {
+    printf("Powering off for %"PRIu64"ms\n", duration_ms);
+    uint64_t ms = powman_timer_get_ms();
+    return powman_example_off_until_time(ms + duration_ms);
+}

powman/powman_example.h

@@ -0,0 +1,9 @@
+#ifndef POWMAN_EXAMPLE_H
+#define POWMAN_EXAMPLE_H
+
+void powman_example_init(uint64_t abs_time_ms);
+int powman_example_off_until_gpio_high(int gpio);
+int powman_example_off_until_time(uint64_t abs_time_ms);
+int powman_example_off_for_ms(uint64_t duration_ms);
+
+#endif

powman/powman_gpio/CMakeLists.txt

@@ -0,0 +1,12 @@
+add_executable(powman_gpio
+        powman_gpio.c
+        )
+target_link_libraries(powman_gpio
+        pico_stdlib
+        powman_example)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(powman_gpio)
+
+# add url via pico_set_program_url
+example_auto_set_url(powman_gpio)

powman/powman_gpio/powman_gpio.c

@@ -0,0 +1,42 @@
+/**
+ * Copyright (c) 2024 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/powman.h"
+#include "powman_example.h"
+
+#ifndef WAKEUP_GPIO
+#define WAKEUP_GPIO 15
+#endif
+
+// How long to wait
+#define PAUSE_TIME_MS 5000
+
+// Got to sleep and wakeup when a GPIO goes high
+// The example will repeatedly wait until GPIO 15 is low then switch off until GPIO 15 goes high
+// To test this you can connect the GPIO to ground and then 3V3(OUT)
+// The debugger will appear to be unresponsive while the device is off
+int main() {
+    stdio_init_all();
+
+    // Initialise the example
+    powman_example_init(1704067200000);
+
+    // Scratch register survives power down
+    printf("Wake up, test run: %u\n", powman_hw->scratch[0]++);
+
+    // Stay awake for a few seconds
+    printf("Awake for %dms\n", PAUSE_TIME_MS);
+    sleep_ms(PAUSE_TIME_MS);
+
+    // power off
+    int rc = powman_example_off_until_gpio_high(WAKEUP_GPIO);
+    hard_assert(rc == PICO_OK);
+
+    hard_assert(false); // should never get here!
+    return 0;
+}

powman/powman_timer/CMakeLists.txt

@@ -0,0 +1,13 @@
+add_executable(powman_timer
+        powman_timer.c
+        )
+target_link_libraries(powman_timer PRIVATE
+        pico_stdlib
+        powman_example
+)
+
+# create map/bin/hex file etc.
+pico_add_extra_outputs(powman_timer)
+
+# add url via pico_set_program_url
+example_auto_set_url(powman_timer)

powman/powman_timer/powman_timer.c

@@ -0,0 +1,37 @@
+/**
+ * Copyright (c) 2024 Raspberry Pi (Trading) Ltd.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <stdio.h>
+#include "pico/stdlib.h"
+#include "hardware/powman.h"
+#include "powman_example.h"
+
+// How long to wait
+#define PAUSE_TIME_MS 5000
+
+// Got to sleep and wakeup after 5 seconds
+// The example will repeatedly wait 5 seconds then switch off for 5 seconds
+// The debugger will appear to be unresponsive while the device is off
+int main() {
+    stdio_init_all();
+
+    // Initialise the example
+    powman_example_init(1704067200000);
+
+    // Scratch register survives power down
+    printf("Wake up, test run: %u\n", powman_hw->scratch[0]++);
+
+    // Stay awake for a few seconds
+    printf("Awake for %dms\n", PAUSE_TIME_MS);
+    sleep_ms(PAUSE_TIME_MS);
+
+    // power off
+    int rc = powman_example_off_for_ms(PAUSE_TIME_MS);
+    hard_assert(rc == PICO_OK);
+
+    hard_assert(false); // should never get here!
+    return 0;
+}