Add configurable display auto-sleep with wake on keypress

Kconfig

@@ -14,4 +14,18 @@ config PROSPECTOR_FIXED_BRIGHTNESS
     int "Fixed display brightness"
     default 50
     range 1 100
-    depends on !PROSPECTOR_USE_AMBIENT_LIGHT_SENSOR
+    depends on !PROSPECTOR_USE_AMBIENT_LIGHT_SENSOR
+
+config PROSPECTOR_DISPLAY_SLEEP_ENABLE
+    bool "Turn off display on idle"
+    default n
+
+config PROSPECTOR_DISPLAY_IDLE_TIMEOUT_MS
+    int "Display idle timeout in ms"
+    default 30000
+    depends on PROSPECTOR_DISPLAY_SLEEP_ENABLE
+
+config PROSPECTOR_DISPLAY_SLEEP_USE_PM
+    bool "Use Zephyr PM to suspend the display (SLEEP_IN)"
+    default n
+    depends on PROSPECTOR_DISPLAY_SLEEP_ENABLE && PM_DEVICE

README.md

@@ -72,12 +72,21 @@ To customize, add config options to your `config/[YOUR KEYBOARD SHIELD].conf` li
 ```ini
 CONFIG_PROSPECTOR_USE_AMBIENT_LIGHT_SENSOR=n
 CONFIG_PROSPECTOR_FIXED_BRIGHTNESS=80
+CONFIG_PROSPECTOR_DISPLAY_SLEEP_ENABLE=y
+CONFIG_PROSPECTOR_DISPLAY_IDLE_TIMEOUT_MS=30000
+# Optional: put display controller into sleep
+# CONFIG_PM_DEVICE=y
+# CONFIG_PROSPECTOR_DISPLAY_SLEEP_USE_PM=y
 ```
 
 ### Available config options:
 | Name                                              | Description                                                               | Default      |
 | ------------------------------------------------- | --------------------------------------------------------------------------| ------------ |
 | `CONFIG_PROSPECTOR_USE_AMBIENT_LIGHT_SENSOR`      | Use ambient light sensor for auto brightness, set to `n` if building without one                              | y            |
-| `CONFIG_PROSPECTOR_FIXED_BRIGHTNESS`               | Set fixed display brightess when not using ambient light sensor           | 50 (1-100)   |
+| `CONFIG_PROSPECTOR_FIXED_BRIGHTNESS`              | Set fixed display brightess when not using ambient light sensor           | 50 (1-100)   |
 | `CONFIG_PROSPECTOR_PROSPECTOR_ROTATE_DISPLAY_180` | Rotate the display 180 degrees                                            | n            |
-| `CONFIG_PROSPECTOR_LAYER_ROLLER_ALL_CAPS`         | Convert layer names to all caps                                           | n            |
+| `CONFIG_PROSPECTOR_LAYER_ROLLER_ALL_CAPS`         | Convert layer names to all caps                                               | n            |
+| `CONFIG_PROSPECTOR_DISPLAY_SLEEP_ENABLE`          | Turn off display and backlight on idle                                    | n            |
+| `CONFIG_PROSPECTOR_DISPLAY_IDLE_TIMEOUT_MS`       | Idle timeout before turning display off (ms)                              | 30000        |
+| `CONFIG_PROSPECTOR_DISPLAY_SLEEP_USE_PM`          | Use Zephyr PM to suspend display controller (requires `CONFIG_PM_DEVICE`) | n            |
+

boards/shields/prospector_adapter/CMakeLists.txt

@@ -12,6 +12,7 @@ if(CONFIG_SHIELD_PROSPECTOR_ADAPTER)
   zephyr_library_sources(src/brightness.c)
   zephyr_library_sources(src/custom_status_screen.c)
   zephyr_library_sources(src/display_rotate_init.c)
+  zephyr_library_sources(src/display_idle.c)
   zephyr_library_sources(src/widgets/layer_roller.c)
   zephyr_library_sources(src/widgets/battery_bar.c)
   zephyr_library_sources_ifdef(CONFIG_DT_HAS_ZMK_BEHAVIOR_CAPS_WORD_ENABLED src/widgets/caps_word_indicator.c)

boards/shields/prospector_adapter/src/brightness.c

@@ -8,6 +8,8 @@
 #include <zephyr/logging/log.h>
 LOG_MODULE_REGISTER(als, 4);
 
+#include "prospector/display_power.h"
+
 static const struct device *pwm_leds_dev = DEVICE_DT_GET_ONE(pwm_leds);
 #define DISP_BL DT_NODE_CHILD_IDX(DT_NODELABEL(disp_bl))
 
@@ -17,7 +19,7 @@ static uint8_t current_brightness = 100;
 
 #define SENSOR_MIN      0       // Minimum sensor reading
 #define SENSOR_MAX      100   // Maximum sensor reading
-#define PWM_MIN         1       // Minimum PWM duty cycle (%) - keep display visible
+#define PWM_MIN         15      // Minimum PWM duty cycle (%) - keep display visible even in dark
 #define PWM_MAX         100     // Maximum PWM duty cycle (%)
 
 #define FADE_STEP                        1
@@ -94,6 +96,15 @@ extern void als_thread(void *d0, void *d1, void *d2) {
 
     while (1) {
 
+        if (prospector_display_is_sleeping()) {
+            if (current_brightness != 0) {
+                led_set_brightness(pwm_leds_dev, DISP_BL, 0);
+                current_brightness = 0;
+            }
+            k_msleep(NORMAL_SAMPLE_SLEEP_MS);
+            continue;
+        }
+
         k_msleep(NORMAL_SAMPLE_SLEEP_MS);
 
 

boards/shields/prospector_adapter/src/display_idle.c

@@ -0,0 +1,158 @@
+#include <zephyr/kernel.h>
+#include <zephyr/device.h>
+#include <zephyr/drivers/display.h>
+#include <zephyr/drivers/led.h>
+#include <zephyr/logging/log.h>
+LOG_MODULE_REGISTER(display_idle, CONFIG_ZMK_LOG_LEVEL);
+
+#include <zmk/event_manager.h>
+#include <zmk/events/keycode_state_changed.h>
+#include <zmk/events/position_state_changed.h>
+
+#if IS_ENABLED(CONFIG_PM_DEVICE)
+#include <zephyr/pm/device.h>
+#endif
+
+#include "prospector/display_power.h"
+
+static const struct device *display_dev;
+static const struct device *pwm_leds_dev;
+
+#define DISP_BL DT_NODE_CHILD_IDX(DT_NODELABEL(disp_bl))
+
+static struct k_work_delayable idle_work;
+static atomic_t sleeping = ATOMIC_INIT(0);
+
+static void prospector_display_blank_on(void) {
+    if (!display_dev) {
+        return;
+    }
+
+#if IS_ENABLED(CONFIG_PROSPECTOR_DISPLAY_SLEEP_USE_PM) && IS_ENABLED(CONFIG_PM_DEVICE)
+    pm_device_action_run(display_dev, PM_DEVICE_ACTION_SUSPEND);
+#else
+    display_blanking_on(display_dev);
+#endif
+}
+
+static void prospector_display_blank_off(void) {
+    if (!display_dev) {
+        return;
+    }
+
+#if IS_ENABLED(CONFIG_PROSPECTOR_DISPLAY_SLEEP_USE_PM) && IS_ENABLED(CONFIG_PM_DEVICE)
+    pm_device_action_run(display_dev, PM_DEVICE_ACTION_RESUME);
+#else
+    display_blanking_off(display_dev);
+#endif
+}
+
+void prospector_display_set_sleeping(bool s) {
+    atomic_set(&sleeping, s ? 1 : 0);
+}
+
+bool prospector_display_is_sleeping(void) {
+    return atomic_get(&sleeping) != 0;
+}
+
+static void display_go_to_sleep(void) {
+    if (prospector_display_is_sleeping()) {
+        return;
+    }
+
+    prospector_display_blank_on();
+
+    if (pwm_leds_dev) {
+        led_set_brightness(pwm_leds_dev, DISP_BL, 0);
+    }
+
+    prospector_display_set_sleeping(true);
+}
+
+static void display_wake_up(void) {
+    if (!prospector_display_is_sleeping()) {
+        return;
+    }
+
+    prospector_display_set_sleeping(false);
+
+    prospector_display_blank_off();
+
+#if !IS_ENABLED(CONFIG_PROSPECTOR_USE_AMBIENT_LIGHT_SENSOR)
+    if (pwm_leds_dev) {
+        led_set_brightness(pwm_leds_dev, DISP_BL, CONFIG_PROSPECTOR_FIXED_BRIGHTNESS);
+    }
+#else
+    /* For ALS mode: force minimum visible brightness on wake (20%)
+     * ALS thread will adjust to proper level shortly after */
+    if (pwm_leds_dev) {
+        led_set_brightness(pwm_leds_dev, DISP_BL, 20);
+    }
+    /* Give ALS thread time to react and adjust brightness */
+    k_msleep(150);
+#endif
+}
+
+static void idle_work_handler(struct k_work *work) {
+    ARG_UNUSED(work);
+    if (!IS_ENABLED(CONFIG_PROSPECTOR_DISPLAY_SLEEP_ENABLE)) {
+        return;
+    }
+    display_go_to_sleep();
+}
+
+static int display_idle_init(const struct device *unused) {
+    ARG_UNUSED(unused);
+
+    display_dev = DEVICE_DT_GET(DT_CHOSEN(zephyr_display));
+    if (!device_is_ready(display_dev)) {
+        return 0;
+    }
+
+    pwm_leds_dev = DEVICE_DT_GET_ONE(pwm_leds);
+    if (!device_is_ready(pwm_leds_dev)) {
+        pwm_leds_dev = NULL;
+    }
+
+    k_work_init_delayable(&idle_work, idle_work_handler);
+
+#if IS_ENABLED(CONFIG_PROSPECTOR_DISPLAY_SLEEP_ENABLE)
+    k_work_schedule(&idle_work, K_MSEC(CONFIG_PROSPECTOR_DISPLAY_IDLE_TIMEOUT_MS));
+#endif
+
+    return 0;
+}
+SYS_INIT(display_idle_init, APPLICATION, 70);
+
+static int on_any_key_event(const zmk_event_t *eh) {
+    if (!IS_ENABLED(CONFIG_PROSPECTOR_DISPLAY_SLEEP_ENABLE)) {
+        return ZMK_EV_EVENT_BUBBLE;
+    }
+
+    const struct zmk_keycode_state_changed *kc = as_zmk_keycode_state_changed(eh);
+    const struct zmk_position_state_changed *pos = as_zmk_position_state_changed(eh);
+
+    bool pressed = false;
+    if (kc) {
+        pressed = kc->state;
+    } else if (pos) {
+        pressed = pos->state;
+    }
+
+    if (!pressed) {
+        return ZMK_EV_EVENT_BUBBLE;
+    }
+
+    display_wake_up();
+#if IS_ENABLED(CONFIG_PROSPECTOR_DISPLAY_SLEEP_ENABLE)
+    k_work_reschedule(&idle_work, K_MSEC(CONFIG_PROSPECTOR_DISPLAY_IDLE_TIMEOUT_MS));
+#endif
+
+    return ZMK_EV_EVENT_BUBBLE;
+}
+
+ZMK_LISTENER(prospector_display_idle, on_any_key_event);
+ZMK_SUBSCRIPTION(prospector_display_idle, zmk_keycode_state_changed);
+ZMK_SUBSCRIPTION(prospector_display_idle, zmk_position_state_changed);
+
+

include/prospector/display_power.h

@@ -0,0 +1,11 @@
+/*
+ * Prospector display power state helper
+ */
+#pragma once
+
+#include <stdbool.h>
+
+void prospector_display_set_sleeping(bool sleeping);
+bool prospector_display_is_sleeping(void);
+
+