1 files changed, 70 insertions, 0 deletions
diff --git a/common/suspend.c b/common/suspend.c
new file mode 100644
index 000000000..6029fe7ff
--- /dev/null
+++ b/common/suspend.c
@@ -0,0 +1,70 @@
+#include "suspend.h"
+#include "matrix.h"
+#include "action.h"
+
+
+void suspend_power_down(void)
+{
+#ifndef NO_SUSPEND_POWER_DOWN
+    // Enable watchdog to wake from MCU sleep
+    cli();
+    wdt_reset();
+
+    // Watchdog Interrupt and System Reset Mode
+    //wdt_enable(WDTO_1S);
+    //WDTCSR |= _BV(WDIE);
+    
+    // Watchdog Interrupt Mode
+    wdt_intr_enable(WDTO_120MS);
+    
+    // TODO: more power saving
+    // See PicoPower application note
+    // - I/O port input with pullup
+    // - prescale clock
+    // - BOD disable
+    // - Power Reduction Register PRR
+    // sleep in power down mode
+    set_sleep_mode(SLEEP_MODE_PWR_DOWN);
+    sleep_enable();
+    sei();
+    sleep_cpu();
+    sleep_disable();
+
+    // Disable watchdog after sleep
+    wdt_disable();
+#endif
+}
+
+bool suspend_wakeup_condition(void)
+{
+    matrix_scan();
+    for (uint8_t r = 0; r < MATRIX_ROWS; r++) {
+        if (matrix_get_row(r)) return true;
+    }
+    return false;
+}
+
+// run immediately after wakeup
+void suspend_wakeup_init(void)
+{
+    // clear matrix and keyboard state
+    matrix_init();
+    clear_keyboard();
+}
+
+#ifndef NO_SUSPEND_POWER_DOWN
+/* watchdog timeout */
+ISR(WDT_vect)
+{
+    /* wakeup from MCU sleep mode */
+/*
+    // blink LED
+    static uint8_t led_state = 0;
+    static uint8_t led_count = 0;
+    led_count++;
+    if ((led_count & 0x07) == 0) {
+        led_set((led_state ^= (1<<USB_LED_CAPS_LOCK)));
+    }
+*/
+}
+#endif