3 files changed, 95 insertions, 1 deletions

diff --git a/common/sleep_led.h b/common/sleep_led.h
index aebdbeaa5..6bdcf558a 100644
--- a/common/sleep_led.h
+++ b/common/sleep_led.h
@@ -1,10 +1,21 @@
 #ifndef SLEEP_LED_H
 #define SLEEP_LED_H
 
-#define NO_SUSPEND_POWER_DOWN
+
+#ifdef SLEEP_LED_ENABLE
 
 void sleep_led_init(void);
 void sleep_led_enable(void);
 void sleep_led_disable(void);
+void sleep_led_toggle(void);
+
+#else
+
+#define sleep_led_init()
+#define sleep_led_enable()
+#define sleep_led_disable()
+#define sleep_led_toggle()
+
+#endif
 
 #endif
diff --git a/common/suspend.c b/common/suspend.c
new file mode 100644
index 000000000..397e0729a
--- /dev/null
+++ b/common/suspend.c
@@ -0,0 +1,51 @@
+#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;
+}
+
+void suspend_wakeup_init(void)
+{
+    matrix_init();
+    clear_keyboard();
+}
diff --git a/common/suspend.h b/common/suspend.h
new file mode 100644
index 000000000..1c1e41ac3
--- /dev/null
+++ b/common/suspend.h
@@ -0,0 +1,32 @@
+#ifndef SUSPEND_H
+#define SUSPEND_H
+
+#include <stdint.h>
+#include <stdbool.h>
+#include <avr/sleep.h>
+#include <avr/wdt.h>
+#include <avr/interrupt.h>
+
+
+#define wdt_intr_enable(value)   \
+__asm__ __volatile__ (  \
+    "in __tmp_reg__,__SREG__" "\n\t"    \
+    "cli" "\n\t"    \
+    "wdr" "\n\t"    \
+    "sts %0,%1" "\n\t"  \
+    "out __SREG__,__tmp_reg__" "\n\t"   \
+    "sts %0,%2" "\n\t" \
+    : /* no outputs */  \
+    : "M" (_SFR_MEM_ADDR(_WD_CONTROL_REG)), \
+    "r" (_BV(_WD_CHANGE_BIT) | _BV(WDE)), \
+    "r" ((uint8_t) ((value & 0x08 ? _WD_PS3_MASK : 0x00) | \
+        _BV(WDIE) | (value & 0x07)) ) \
+    : "r0"  \
+)
+
+
+void suspend_power_down(void);
+bool suspend_wakeup_condition(void);
+void suspend_wakeup_init(void);
+
+#endif