samples: boards: nrf: system_off: Extend sample

Add option to not go to system off but instead go to sleep.
Extending sample to use second button (Button 1). Sample goes
to system off as before and when Button 0 is pressed it wakes
up and goes to system off again. If Button 1 is pressed then
it wakes up but goes to sleep again.

Signed-off-by: Krzysztof Chruściński <[email protected]>

Author: nordic-krch

samples/boards/nordic/system_off/README.rst

@@ -8,7 +8,10 @@ Overview
 ********
 
 This sample can be used for basic power measurement and as an example of
-deep sleep on Nordic platforms.
+deep sleep on Nordic platforms. After pin reset application goes to system off.
+Pressing Button 0 wakes up the system and after printing messages goes again to
+system off. Pressing Button 1 wakes up the system but after printing messages
+system goes to sleep instead of system off.
 
 RAM Retention
 =============

samples/boards/nordic/system_off/src/main.c

@@ -15,24 +15,34 @@
 #include <zephyr/pm/device.h>
 #include <zephyr/sys/poweroff.h>
 #include <zephyr/sys/util.h>
+#include <hal/nrf_gpio.h>
 
 #if IS_ENABLED(CONFIG_GRTC_WAKEUP_ENABLE)
 #include <zephyr/drivers/timer/nrf_grtc_timer.h>
 #define DEEP_SLEEP_TIME_S 2
 #else
 static const struct gpio_dt_spec sw0 = GPIO_DT_SPEC_GET(DT_ALIAS(sw0), gpios);
+static const struct gpio_dt_spec sw1 = GPIO_DT_SPEC_GET(DT_ALIAS(sw1), gpios);
+static const uint32_t port_sw1 = DT_PROP(DT_GPIO_CTLR_BY_IDX(DT_ALIAS(sw1), gpios, 0), port);
 #endif
 
 int main(void)
 {
 	int rc;
 	const struct device *const cons = DEVICE_DT_GET(DT_CHOSEN(zephyr_console));
+	uint32_t nrf_pin_sw1 = 32 * port_sw1 + sw1.pin;
+	bool do_poweroff = true;
 
 	if (!device_is_ready(cons)) {
 		printf("%s: device not ready.\n", cons->name);
 		return 0;
 	}
 
+	if (nrf_gpio_pin_latch_get(nrf_pin_sw1)) {
+		nrf_gpio_pin_latch_clear(nrf_pin_sw1);
+		do_poweroff = false;
+	}
+
 	printf("\n%s system off demo\n", CONFIG_BOARD);
 
 	if (IS_ENABLED(CONFIG_APP_USE_RETAINED_MEM)) {
@@ -66,13 +76,29 @@ int main(void)
 		return 0;
 	}
 
+	rc = gpio_pin_configure_dt(&sw1, GPIO_INPUT);
+	if (rc < 0) {
+		printf("Could not configure sw1 GPIO (%d)\n", rc);
+		return 0;
+	}
+
 	rc = gpio_pin_interrupt_configure_dt(&sw0, GPIO_INT_LEVEL_ACTIVE);
 	if (rc < 0) {
 		printf("Could not configure sw0 GPIO interrupt (%d)\n", rc);
 		return 0;
 	}
 
-	printf("Entering system off; press sw0 to restart\n");
+	rc = gpio_pin_interrupt_configure_dt(&sw1, GPIO_INT_LEVEL_ACTIVE);
+	if (rc < 0) {
+		printf("Could not configure sw0 GPIO interrupt (%d)\n", rc);
+		return 0;
+	}
+
+	if (do_poweroff) {
+		printf("Entering system off; press sw0 or sw1 to restart\n");
+	} else {
+		printf("Button sw1 pressed, not entering system off\n");
+	}
 #endif
 
 	rc = pm_device_action_run(cons, PM_DEVICE_ACTION_SUSPEND);
@@ -87,7 +113,11 @@ int main(void)
 		retained_update();
 	}
 
-	sys_poweroff();
+	if (do_poweroff) {
+		sys_poweroff();
+	} else {
+		k_sleep(K_FOREVER);
+	}
 
 	return 0;
 }