intel_x86: Auto power-on after battery SOC is above minimum required

If power-up is inhibited by charger because of battery SOC, then check
for the conditions again on BATTERY_SOC_CHANGE. This allows the EC to
boot the AP up on connecting AC power and SOC going above the minimum
required.

BUG=b:65864825
BRANCH=None
TEST=Verified following on coral and soraka:
1. Discharge battery to ~0%
2. Connect AC power ==> Power-up is inhibited
3. When battery SOC reaches 1%. AP is not taken out of reset:
"[12.974428 Battery 1% / 8h:4 to full]
[12.980439 power-up still inhibited]"
4. When battery SOC reaches 2%, AP is taken out of reset:
"[9.230148 Battery 2% / 4h:5 to full]
[9.236122 Battery SOC ok to boot AP!]"

Change-Id: Ifa89f8929987d86c9e02530b663d563dbe25ed85
Signed-off-by: Furquan Shaikh <furquan@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/753294
Reviewed-by: Shawn N <shawnn@chromium.org>

1 files changed, 49 insertions, 5 deletions

diff --git a/power/intel_x86.c b/power/intel_x86.c
index c1962965b3..59b2d529aa 100644
--- a/power/intel_x86.c
+++ b/power/intel_x86.c
@@ -58,6 +58,42 @@ static const int sleep_sig[] = {
 
 static int power_s5_up;       /* Chipset is sequencing up or down */
 
+#ifdef CONFIG_CHARGER
+/* Flag to indicate if power up was inhibited due to low battery SOC level. */
+static int power_up_inhibited;
+
+/*
+ * Check if AP power up should be inhibited.
+ * 0 = Ok to boot up AP
+ * 1 = AP power up is inhibited.
+ */
+static int is_power_up_inhibited(void)
+{
+	/* Defaulting to power button not pressed. */
+	const int power_button_pressed = 0;
+
+	return charge_prevent_power_on(power_button_pressed) ||
+		charge_want_shutdown();
+}
+
+static void power_up_inhibited_cb(void)
+{
+	if (!power_up_inhibited)
+		return;
+
+	if (is_power_up_inhibited()) {
+		CPRINTS("power-up still inhibited");
+		return;
+	}
+
+	CPRINTS("Battery SOC ok to boot AP!");
+	power_up_inhibited = 0;
+
+	chipset_exit_hard_off();
+}
+DECLARE_HOOK(HOOK_BATTERY_SOC_CHANGE, power_up_inhibited_cb, HOOK_PRIO_DEFAULT);
+#endif
+
 /* Get system sleep state through GPIOs or VWs */
 static inline int chipset_get_sleep_signal(enum sys_sleep_state state)
 {
@@ -275,22 +311,30 @@ enum power_state common_intel_x86_power_handle_state(enum power_state state)
 #ifdef CONFIG_CHARGER
 		{
 		int tries = 0;
+
 		/*
 		 * Allow charger to be initialized for upto defined tries,
 		 * in case we're trying to boot the AP with no battery.
 		 */
-		while (charge_prevent_power_on(0) &&
-		       tries++ < CHARGER_INITIALIZED_TRIES) {
+		while ((tries < CHARGER_INITIALIZED_TRIES) &&
+		       is_power_up_inhibited()) {
 			msleep(CHARGER_INITIALIZED_DELAY_MS);
+			tries++;
 		}
 
-		/* Return to G3 if battery level is too low */
-		if (charge_want_shutdown() ||
-		    tries > CHARGER_INITIALIZED_TRIES) {
+		/*
+		 * Return to G3 if battery level is too low. Set
+		 * power_up_inhibited in order to check the eligibility to boot
+		 * AP up after battery SOC changes.
+		 */
+		if (tries == CHARGER_INITIALIZED_TRIES) {
 			CPRINTS("power-up inhibited");
+			power_up_inhibited = 1;
 			chipset_force_shutdown();
 			return POWER_G3;
 		}
+
+		power_up_inhibited = 0;
 		}
 #endif