1 files changed, 98 insertions, 0 deletions
diff --git a/common/avr/suspend.c b/common/avr/suspend.c
new file mode 100644
index 0000000000..f44a036beb
--- /dev/null
+++ b/common/avr/suspend.c
@@ -0,0 +1,98 @@
+#include <stdbool.h>
+#include <avr/sleep.h>
+#include <avr/wdt.h>
+#include <avr/interrupt.h>
+#include "matrix.h"
+#include "action.h"
+#include "backlight.h"
+#include "suspend_avr.h"
+#include "suspend.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)
+{
+#ifdef BACKLIGHT_ENABLE
+    backlight_set(0);
+#endif
+#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 keyboard state
+    clear_keyboard();
+#ifdef BACKLIGHT_ENABLE
+    backlight_init();
+#endif
+}
+
+#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