kernel:dwc3 delay extcon module registeration

dwc3 driver now replies on extcon suppliers registered from another ko
in timing sequence, dwc3 is probed much earlier than the ko registeration.
To work with the related ko driver correctly, add a delayed work item to
check the extcon status periodicly. The frequency is 1HZ and it just stops
whenever the required extcon suppliers defined in dtsi have been found.

Change-Id: Ia7c50165eab13b0274590c744f49061fa6ef7c03
Reviewed-on: https://gerrit.mot.com/2130472
SME-Granted: SME Approvals Granted
SLTApproved: Slta Waiver
Tested-by: Jira Key
Reviewed-by: Wei Xu <xuwei9@lenovo.com>
Reviewed-by: Xiangpo Zhao <zhaoxp3@motorola.com>
Submit-Approved: Jira Key

drivers/usb/dwc3/dwc3-msm.c

@@ -307,6 +307,7 @@ struct dwc3_msm {
 	struct workqueue_struct *dwc3_wq;
 	struct workqueue_struct *sm_usb_wq;
 	struct delayed_work	sm_work;
+	struct delayed_work	extcon_work;
 	unsigned long		inputs;
 	unsigned int		max_power;
 	bool			charging_disabled;
@@ -388,7 +389,7 @@ static void dwc3_msm_notify_event(struct dwc3 *dwc, unsigned int event,
 						unsigned int value);
 static int dwc3_usb_blocking_sync(struct notifier_block *nb,
 					unsigned long event, void *ptr);
-
+static void dwc3_extcon_reg_work(struct work_struct *w);
 /**
  *
  * Read register with debug info.
@@ -3381,6 +3382,7 @@ static int dwc3_msm_vbus_notifier(struct notifier_block *nb,
 		if (mdwc->vbus_active == event)
 			return NOTIFY_DONE;
 		mdwc->vbus_active = event;
+		mdwc->check_eud_state = false;
 	}
 
 	/*
@@ -3717,6 +3719,7 @@ static int dwc3_msm_probe(struct platform_device *pdev)
 	INIT_WORK(&mdwc->restart_usb_work, dwc3_restart_usb_work);
 	INIT_WORK(&mdwc->vbus_draw_work, dwc3_msm_vbus_draw_work);
 	INIT_DELAYED_WORK(&mdwc->sm_work, dwc3_otg_sm_work);
+	INIT_DELAYED_WORK(&mdwc->extcon_work, dwc3_extcon_reg_work);
 	INIT_DELAYED_WORK(&mdwc->perf_vote_work, msm_dwc3_perf_vote_work);
 	INIT_DELAYED_WORK(&mdwc->sdp_check, check_for_sdp_connection);
 
@@ -4008,33 +4011,9 @@ static int dwc3_msm_probe(struct platform_device *pdev)
 	mutex_init(&mdwc->suspend_resume_mutex);
 
 	if (of_property_read_bool(node, "extcon")) {
-		ret = dwc3_msm_extcon_register(mdwc);
-		if (ret)
-			goto put_dwc3;
-
-		/*
-		 * dpdm regulator will be turned on to perform apsd
-		 * (automatic power source detection). dpdm regulator is
-		 * used to float (or high-z) dp/dm lines. Do not reset
-		 * controller/phy if regulator is turned on.
-		 * if dpdm is not present controller can be reset
-		 * as this controller may not be used for charger detection.
-		 */
-		mdwc->dpdm_reg = devm_regulator_get_optional(&pdev->dev,
-				"dpdm");
-		if (IS_ERR(mdwc->dpdm_reg)) {
-			dev_dbg(mdwc->dev, "assume cable is not connected\n");
-			mdwc->dpdm_reg = NULL;
-		}
-
-		if (!mdwc->vbus_active && mdwc->dpdm_reg &&
-				regulator_is_enabled(mdwc->dpdm_reg)) {
-			mdwc->dpdm_nb.notifier_call = dwc_dpdm_cb;
-			regulator_register_notifier(mdwc->dpdm_reg,
-					&mdwc->dpdm_nb);
-		} else {
-			queue_delayed_work(mdwc->sm_usb_wq, &mdwc->sm_work, 0);
-		}
+		/* sm work only can be triggerred after extcon register successfully */
+		queue_delayed_work(mdwc->sm_usb_wq, &mdwc->extcon_work, 0);
+		queue_delayed_work(mdwc->sm_usb_wq, &mdwc->sm_work, 0);
 	} else {
 		switch (dwc->dr_mode) {
 		case USB_DR_MODE_DRD:
@@ -4615,6 +4594,71 @@ set_prop:
 	return 0;
 }
 
+static void dwc3_extcon_reg_work(struct work_struct *w)
+{
+	struct dwc3_msm *mdwc = container_of(w, struct dwc3_msm, extcon_work.work);	
+	struct device_node *node = mdwc->dev->of_node;
+	struct extcon_dev *edev;
+	int idx, extcon_cnt;
+
+	/* check if related extcon has been installed */
+
+	extcon_cnt = of_count_phandle_with_args(node, "extcon", NULL);
+	if (extcon_cnt < 0) {
+		dev_err(mdwc->dev, "of_count_phandle_with_args failed\n");
+		return;
+	}
+
+	for (idx = 0; idx < extcon_cnt; idx++) {
+		edev = extcon_get_edev_by_phandle(mdwc->dev, idx);
+		if (IS_ERR(edev) && PTR_ERR(edev) != -ENODEV) {
+			dev_err(mdwc->dev, "get device failed at:%d, delay and retry\n", idx);
+			break;
+		}
+
+		if (IS_ERR_OR_NULL(edev))
+			continue;
+	}
+
+	if (idx != extcon_cnt) {
+		dev_dbg(mdwc->dev, "sched another extcon work\n");
+		queue_delayed_work(mdwc->sm_usb_wq, &mdwc->extcon_work, HZ);
+		return;
+	}
+	else {
+		if (dwc3_msm_extcon_register(mdwc)) {
+			dev_err(mdwc->dev, "extcon register failed, delayed work stopped\n");
+			return;
+		}
+
+		/*
+			* dpdm regulator will be turned on to perform apsd
+			* (automatic power source detection). dpdm regulator is
+			* used to float (or high-z) dp/dm lines. Do not reset
+			* controller/phy if regulator is turned on.
+			* if dpdm is not present controller can be reset
+			* as this controller may not be used for charger detection.
+			*/
+		mdwc->dpdm_reg = devm_regulator_get_optional(mdwc->dev,
+				"dpdm");
+		if (IS_ERR(mdwc->dpdm_reg)) {
+			dev_dbg(mdwc->dev, "assume cable is not connected\n");
+			mdwc->dpdm_reg = NULL;
+		}
+
+		if (!mdwc->vbus_active && mdwc->dpdm_reg &&
+				regulator_is_enabled(mdwc->dpdm_reg)) {
+			dev_dbg(mdwc->dev, "dpdm on\n");
+
+			mdwc->dpdm_nb.notifier_call = dwc_dpdm_cb;
+			regulator_register_notifier(mdwc->dpdm_reg,
+					&mdwc->dpdm_nb);
+		} else {
+			dev_dbg(mdwc->dev, "dpdm off\n");
+		}
+	}
+
+}
 
 /**
  * dwc3_otg_sm_work - workqueue function.