Chibios: use WFI in idle. WIP suspend stuff.

tmk_core/common/chibios/sleep_led.c

@@ -4,6 +4,10 @@
 #include "sleep_led.h"
 
 void sleep_led_init(void) {
+	// we could go the 'software way' -- just enable *some* timer
+	// and go with callbacks
+	// or we could go the 'hardware way' -- and use timer output to
+	// pins directly
 }
 
 void sleep_led_enable(void) {

tmk_core/common/chibios/suspend.c

@@ -1,8 +1,65 @@
 /* TODO */
 
-#include <stdbool.h>
+#include "ch.h"
+#include "hal.h"
 
+#include "matrix.h"
+#include "action.h"
+#include "action_util.h"
+#include "mousekey.h"
+#include "host.h"
+#include "backlight.h"
+#include "suspend.h"
 
-void suspend_power_down(void) {}
-bool suspend_wakeup_condition(void) { return true; }
-void suspend_wakeup_init(void) {}
+void suspend_idle(uint8_t time) {
+	// TODO: this is not used anywhere - what units is 'time' in?
+	chThdSleepMilliseconds(time);
+}
+
+void suspend_power_down(void) {
+	// TODO: figure out what to power down and how
+	// shouldn't power down TPM/FTM if we want a breathing LED
+	// also shouldn't power down USB
+
+	// on AVR, this enables the watchdog for 15ms (max), and goes to
+	// SLEEP_MODE_PWR_DOWN
+
+	chThdSleepMilliseconds(17);
+}
+
+__attribute__ ((weak)) void matrix_power_up(void) {}
+__attribute__ ((weak)) void matrix_power_down(void) {}
+bool suspend_wakeup_condition(void)
+{
+    matrix_power_up();
+    matrix_scan();
+    matrix_power_down();
+    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
+    // need to do it manually, because we're running from ISR
+    //  and clear_keyboard() calls print
+    // so only clear the variables in memory
+    // the reports will be sent from main.c afterwards
+    // or if the PC asks for GET_REPORT
+    clear_mods();
+    clear_weak_mods();
+    clear_keys();
+#ifdef MOUSEKEY_ENABLE
+    mousekey_clear();
+#endif /* MOUSEKEY_ENABLE */
+#ifdef EXTRAKEY_ENABLE
+    host_system_send(0);
+    host_consumer_send(0);
+#endif /* EXTRAKEY_ENABLE */
+#ifdef BACKLIGHT_ENABLE
+    backlight_init();
+#endif /* BACKLIGHT_ENABLE */
+}