Incorporate CABLE_DET circuit change

Now that when ID_MUX=1, DP_SNS can be connected to either ID_OUT or
CABLE_DET, we need to handle the case where a video dongle is not
reflected by DP_SNS going low. This is done by leaving ID_MUX=1 for USB
host and monitor its detachment by sensing VBUS. As for unpowered
dongle, we just ignore it when it's not recognized.

Note that due to the polarity of CABLE_DET, we now sense dongle
detachement by DP_SNS < 0.25V. To support older boards with ID_OUT
connected, we also disconnect video dongle on system suspend and
shutdown.

BUG=chrome-os-partner:19911
TEST=Powered/unpowered video dongle detected correctly.
TEST=Add a console command to simulate CABLE_DET being high. With that,
check battery charges with powered video dongle. Check nothing happens
with unpowered video dongle.
TEST=Check video dongle considered disconnected when OTG dongle plugged
in or system shutdown.
BRANCH=spring

Change-Id: If7b530b67c98c85017ca663d43c5148f0eb9163c
Signed-off-by: Vic Yang <victoryang@chromium.org>
Reviewed-on: https://gerrit.chromium.org/gerrit/58070
Reviewed-by: Vincent Palatin <vpalatin@chromium.org>

1 files changed, 81 insertions, 21 deletions

diff --git a/common/extpower_usb.c b/common/extpower_usb.c
index 17ad401001..51068452e6 100644
--- a/common/extpower_usb.c
+++ b/common/extpower_usb.c
@@ -46,7 +46,7 @@ enum ilim_config {
 #define TOAD_DEVICE_TYPE (TSU6721_TYPE_UART | TSU6721_TYPE_AUDIO3)
 
 /* Voltage threshold of D+ for video */
-#define VIDEO_ID_THRESHOLD	1335
+#define VIDEO_ID_THRESHOLD	250
 
 /*
  * Mapping from PWM duty to current:
@@ -97,6 +97,7 @@ static int user_pwm_duty = -1;
 static int pwm_fast_mode;
 
 static int pending_tsu6721_reset;
+static int restore_id_mux;
 
 static enum {
 	LIMIT_NORMAL,
@@ -106,6 +107,7 @@ static enum {
 static enum {
 	ADC_WATCH_NONE,
 	ADC_WATCH_TOAD,
+	ADC_WATCH_USB,
 } current_watchdog = ADC_WATCH_NONE;
 
 struct {
@@ -284,12 +286,24 @@ static int probe_video(int device_type)
 	gpio_set_level(GPIO_ID_MUX, 1);
 	msleep(DELAY_ID_MUX_MS);
 
-	if (adc_read_channel(ADC_CH_USB_DP_SNS) > VIDEO_ID_THRESHOLD) {
-		/* Actually an USB host */
-		gpio_set_level(GPIO_ID_MUX, 0);
-		msleep(DELAY_ID_MUX_MS);
-		tsu6721_enable_interrupts();
-		return device_type;
+	if (adc_read_channel(ADC_CH_USB_DP_SNS) < VIDEO_ID_THRESHOLD) {
+		if (device_type & TSU6721_TYPE_VBUS_DEBOUNCED) {
+			/*
+			 * Either USB host or video dongle.
+			 * Leave ID_MUX high so we see the change on
+			 * DP_SNS if any.
+			 *
+			 * ADC watchdog is responsible for sensing a
+			 * detach event and switch back ID_MUX.
+			 */
+			return device_type;
+		} else {
+			/* Unhandled unpowered video dongle. Ignore it. */
+			gpio_set_level(GPIO_ID_MUX, 0);
+			msleep(DELAY_ID_MUX_MS);
+			tsu6721_enable_interrupts();
+			return TSU6721_TYPE_NONE;
+		}
 	} else {
 		/* Not USB host but video */
 		device_type = video_dev_type(device_type);
@@ -369,15 +383,27 @@ static void pwm_nominal_duty_cycle(int percent)
 	pwm_fast_mode = 1;
 }
 
-static void adc_watch_toad(void)
+static void adc_watch_vbus(int high, int low)
 {
-	/* Watch VBUS and interrupt if voltage goes under 3V. */
-	adc_enable_watchdog(STM32_AIN(5), 4095, 1800);
+	adc_enable_watchdog(STM32_AIN(5), high, low);
 	task_clear_pending_irq(STM32_IRQ_ADC_1);
 	task_enable_irq(STM32_IRQ_ADC_1);
+}
+
+static void adc_watch_toad(void)
+{
+	/* Watch VBUS and interrupt if voltage goes under 3V. */
+	adc_watch_vbus(4095, 1800);
 	current_watchdog = ADC_WATCH_TOAD;
 }
 
+static void adc_watch_usb(void)
+{
+	/* Watch VBUS and interrupt if voltage goes under 3V. */
+	adc_watch_vbus(4095, 1800);
+	current_watchdog = ADC_WATCH_USB;
+}
+
 static int usb_has_power_input(int dev_type)
 {
 	if (dev_type & TSU6721_TYPE_JIG_UART_ON)
@@ -534,12 +560,15 @@ static void usb_device_change(int dev_type)
 	if ((dev_type & TOAD_DEVICE_TYPE) &&
 	    (dev_type & TSU6721_TYPE_VBUS_DEBOUNCED))
 		adc_watch_toad();
+	else if (dev_type & TSU6721_TYPE_USB_HOST)
+		adc_watch_usb();
 
-	usb_log_dev_type(dev_type);
-
-	keyboard_send_battery_key();
+	if (dev_type != current_dev_type) {
+		usb_log_dev_type(dev_type);
+		keyboard_send_battery_key();
+		current_dev_type = dev_type;
+	}
 
-	current_dev_type = dev_type;
 	if (dev_type)
 		disable_sleep(SLEEP_MASK_USB_PWR);
 	else
@@ -584,6 +613,12 @@ void extpower_charge_update(int force_update)
 {
 	int int_val = 0;
 
+	if (restore_id_mux) {
+		gpio_set_level(GPIO_ID_MUX, 0);
+		msleep(DELAY_ID_MUX_MS);
+		restore_id_mux = 0;
+	}
+
 	if (pending_tsu6721_reset) {
 		current_watchdog = ADC_WATCH_NONE;
 		adc_disable_watchdog();
@@ -634,10 +669,17 @@ void extpower_interrupt(enum gpio_signal signal)
 
 static void adc_watchdog_interrupt(void)
 {
-	if (current_watchdog == ADC_WATCH_TOAD) {
+	switch (current_watchdog) {
+	case ADC_WATCH_USB:
+		restore_id_mux = 1;
+		/* Fall through */
+	case ADC_WATCH_TOAD:
 		pending_tsu6721_reset = 1;
 		task_disable_irq(STM32_IRQ_ADC_1);
 		task_wake(TASK_ID_CHARGER);
+		break;
+	default:
+		break;
 	}
 }
 DECLARE_IRQ(STM32_IRQ_ADC_1, adc_watchdog_interrupt, 2);
@@ -695,6 +737,18 @@ static void pwm_tweak(void)
 }
 DECLARE_HOOK(HOOK_SECOND, pwm_tweak, HOOK_PRIO_DEFAULT);
 
+static void usb_detach_video(void)
+{
+	if (!(current_dev_type & TSU6721_TYPE_JIG_UART_ON))
+		return;
+	set_video_power(0);
+	restore_id_mux = 1;
+	pending_tsu6721_reset = 1;
+	task_wake(TASK_ID_CHARGER);
+}
+DECLARE_HOOK(HOOK_CHIPSET_SUSPEND, usb_detach_video, HOOK_PRIO_DEFAULT);
+DECLARE_HOOK(HOOK_CHIPSET_SHUTDOWN, usb_detach_video, HOOK_PRIO_DEFAULT);
+
 static void usb_monitor_detach(void)
 {
 	int vbus;
@@ -702,12 +756,8 @@ static void usb_monitor_detach(void)
 	if (!(current_dev_type & TSU6721_TYPE_JIG_UART_ON))
 		return;
 
-	if (adc_read_channel(ADC_CH_USB_DP_SNS) > VIDEO_ID_THRESHOLD) {
-		set_video_power(0);
-		gpio_set_level(GPIO_ID_MUX, 0);
-		msleep(DELAY_ID_MUX_MS);
-		tsu6721_enable_interrupts();
-		usb_device_change(TSU6721_TYPE_NONE);
+	if (adc_read_channel(ADC_CH_USB_DP_SNS) < VIDEO_ID_THRESHOLD) {
+		usb_detach_video();
 		return;
 	}
 
@@ -726,6 +776,16 @@ static void usb_monitor_detach(void)
 }
 DECLARE_HOOK(HOOK_SECOND, usb_monitor_detach, HOOK_PRIO_DEFAULT);
 
+static void usb_monitor_cable_det(void)
+{
+	if (!(current_dev_type & TSU6721_TYPE_USB_HOST))
+		return;
+
+	if (adc_read_channel(ADC_CH_USB_DP_SNS) < VIDEO_ID_THRESHOLD)
+		adc_watchdog_interrupt();
+}
+DECLARE_HOOK(HOOK_SECOND, usb_monitor_cable_det, HOOK_PRIO_DEFAULT);
+
 /*****************************************************************************/
 /*
  * Console commands for debugging.