1 files changed, 119 insertions, 0 deletions
diff --git a/chip/stm32/clock-stm32l.c b/chip/stm32/clock-stm32l.c
index b2de4e8073..2f1b0f655a 100644
--- a/chip/stm32/clock-stm32l.c
+++ b/chip/stm32/clock-stm32l.c
@@ -14,6 +14,18 @@
 #include "registers.h"
 #include "util.h"
 
+#ifdef CONFIG_STM32L_FAKE_HIBERNATE
+#include "extpower.h"
+#include "keyboard_config.h"
+#include "lid_switch.h"
+#include "power.h"
+#include "power_button.h"
+#include "system.h"
+#include "task.h"
+
+static int fake_hibernate;
+#endif
+
 /* High-speed oscillator is 16 MHz */
 #define HSI_CLOCK 16000000
 /*
@@ -159,6 +171,113 @@ void clock_enable_module(enum module_id module, int enable)
 	clock_mask = new_mask;
 }
 
+#ifdef CONFIG_STM32L_FAKE_HIBERNATE
+/*
+ *  This is for NOT having enough hibernate (more precisely, the stand-by mode)
+ *  wake-up source pin. STM32L100 supports 3 wake-up source pins:
+ *
+ *     WKUP1 (PA0)  -- used for ACOK_PMU
+ *     WKUP2 (PC13) -- used for LID_OPEN
+ *     WKUP3 (PE6)  -- cannot be used due to IC package.
+ *
+ *  However, we need the power button as a wake-up source as well and there is
+ *  no available pin for us (we don't want to move the ACOK_PMU pin).
+ *
+ *  Fortunately, the STM32L is low-power enough so that we don't need the
+ *  super-low-power mode. So, we fake this hibernate mode and accept the
+ *  following wake-up source.
+ *
+ *     RTC alarm  (faked as well).
+ *     Power button
+ *     Lid open
+ *     AC detected
+ *
+ *  The original issue is here: crosbug.com/p/25435.
+ */
+void __enter_hibernate(uint32_t seconds, uint32_t microseconds)
+{
+	int i;
+	fake_hibernate = 1;
+
+#ifdef CONFIG_POWER_COMMON
+	/*
+	 * A quick hack to stop annoying messages from charger task.
+	 *
+	 * When the battery is under 3%, the power task would call
+	 * power_off() to shutdown AP. However, the power_off() would
+	 * notify the HOOK_CHIPSET_SHUTDOWN, where the last hook is
+	 * charge_shutdown() and it hibernates the power task (infinite
+	 * loop -- not real CPU hibernate mode). Unfortunately, the
+	 * charger task is still running. It keeps generating annoying
+	 * log message.
+	 *
+	 * Thus, the hack is to set the power state machine (before we
+	 * enter infinite loop) so that the charger task thinks the AP
+	 * is off and stops generating messages.
+	 */
+	power_set_state(POWER_G3);
+#endif
+
+	/*
+	 * Change keyboard outputs to high-Z to reduce power draw.
+	 * We don't need corresponding code to change them back,
+	 * because fake hibernate is always exited with a reboot.
+	 *
+	 * A little hacky to do this here.
+	 */
+	for (i = GPIO_KB_OUT00; i < GPIO_KB_OUT00 + KEYBOARD_COLS; i++)
+		gpio_set_flags(i, GPIO_INPUT);
+
+	ccprintf("[%T fake hibernate. waits for power button/lid/RTC/AC]\n");
+	cflush();
+
+	if (seconds || microseconds) {
+		if (seconds)
+			sleep(seconds);
+		if (microseconds)
+			usleep(microseconds);
+	} else {
+		while (1)
+			task_wait_event(-1);
+	}
+
+	ccprintf("[%T fake RTC alarm fires. resets EC]\n");
+	cflush();
+	system_reset(SYSTEM_RESET_HARD);
+}
+
+static void fake_hibernate_power_button_hook(void)
+{
+	if (fake_hibernate && lid_is_open() && !power_button_is_pressed()) {
+		ccprintf("[%T %s() resets EC]\n", __func__);
+		cflush();
+		system_reset(SYSTEM_RESET_HARD);
+	}
+}
+DECLARE_HOOK(HOOK_POWER_BUTTON_CHANGE, fake_hibernate_power_button_hook,
+	HOOK_PRIO_DEFAULT);
+
+static void fake_hibernate_lid_hook(void)
+{
+	if (fake_hibernate && lid_is_open()) {
+		ccprintf("[%T %s() resets EC]\n", __func__);
+		cflush();
+		system_reset(SYSTEM_RESET_HARD);
+	}
+}
+DECLARE_HOOK(HOOK_LID_CHANGE, fake_hibernate_lid_hook, HOOK_PRIO_DEFAULT);
+
+static void fake_hibernate_ac_hook(void)
+{
+	if (fake_hibernate && extpower_is_present()) {
+		ccprintf("[%T %s() resets EC]\n", __func__);
+		cflush();
+		system_reset(SYSTEM_RESET_HARD);
+	}
+}
+DECLARE_HOOK(HOOK_AC_CHANGE, fake_hibernate_ac_hook, HOOK_PRIO_DEFAULT);
+#endif
+
 void clock_init(void)
 {
 	/*