usb: chipidea: Use extcon framework for ID and VBUS detection

Rather than relying on special USB/PHY pins/registers use the
generic extcon framework with its extcon-usb-gpio implementation
to detect ID and VBUS changes.

Signed-off-by: Sanchayan Maity <maitysanchayan@gmail.com>
Signed-off-by: Stefan Agner <stefan.agner@toradex.com>

3 files changed, 108 insertions, 5 deletions

diff --git a/drivers/usb/chipidea/ci.h b/drivers/usb/chipidea/ci.h
index 207e4a34be07..7aeb92288643 100644
--- a/drivers/usb/chipidea/ci.h
+++ b/drivers/usb/chipidea/ci.h
@@ -18,6 +18,7 @@
 #include <linux/usb.h>
 #include <linux/usb/gadget.h>
 #include <linux/usb/otg-fsm.h>
+#include <linux/extcon.h>
 
 /******************************************************************************
  * DEFINE
@@ -256,6 +257,12 @@ struct ci_hdrc {
 	bool				in_lpm;
 	bool				wakeup_int;
 	enum ci_revision		rev;
+
+	struct extcon_specific_cable_nb extcon_vbus_dev;
+	struct extcon_specific_cable_nb extcon_id_dev;
+	struct notifier_block		vbus_nb;
+	struct notifier_block		id_nb;
+
 	/* register save area for suspend&resume */
 	u32				pm_command;
 	u32				pm_status;
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 3b77b04896f8..30dbc9ce3bcf 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -606,6 +606,17 @@ static int ci_get_platdata(struct device *dev,
 {
 	int ret;
 
+	if (of_property_read_bool(dev->of_node, "extcon")) {
+		platdata->edev = extcon_get_edev_by_phandle(dev, 0);
+		if (IS_ERR(platdata->edev)) {
+			if (PTR_ERR(platdata->edev) == -EPROBE_DEFER)
+				return -EPROBE_DEFER;
+			dev_err(dev, "Could not get extcon device: %ld\n",
+				PTR_ERR(platdata->edev));
+		}
+		platdata->flags |= CI_HDRC_DUAL_ROLE_NOT_OTG;
+	}
+
 	if (!platdata->phy_mode)
 		platdata->phy_mode = of_usb_get_phy_mode(dev->of_node);
 
@@ -797,6 +808,42 @@ static inline void ci_role_destroy(struct ci_hdrc *ci)
 	ci_hdrc_host_destroy(ci);
 }
 
+static int ci_id_notifier(struct notifier_block *nb, unsigned long event,
+			  void *ptr)
+{
+	struct ci_hdrc *ci = container_of(nb, struct ci_hdrc, id_nb);
+
+	pm_runtime_get_sync(ci->dev);
+
+	ci_role_stop(ci);
+
+	hw_wait_phy_stable();
+
+	if (ci_role_start(ci, event ? CI_ROLE_HOST : CI_ROLE_GADGET))
+		dev_err(ci->dev, "Can't start %s role\n", ci_role(ci)->name);
+
+	pm_runtime_put_sync(ci->dev);
+
+	return NOTIFY_DONE;
+}
+
+static int ci_vbus_notifier(struct notifier_block *nb, unsigned long event,
+			    void *ptr)
+{
+	struct ci_hdrc *ci = container_of(nb, struct ci_hdrc, vbus_nb);
+
+	pm_runtime_get_sync(ci->dev);
+
+	if (event)
+		usb_gadget_vbus_connect(&ci->gadget);
+	else
+		usb_gadget_vbus_disconnect(&ci->gadget);
+
+	pm_runtime_put_sync(ci->dev);
+
+	return NOTIFY_DONE;
+}
+
 static void ci_get_otg_capable(struct ci_hdrc *ci)
 {
 	if (ci->platdata->flags & CI_HDRC_DUAL_ROLE_NOT_OTG)
@@ -897,6 +944,22 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		return -ENODEV;
 	}
 
+	if (ci->platdata->edev) {
+		ci->vbus_nb.notifier_call = ci_vbus_notifier;
+		ret = extcon_register_interest(&ci->extcon_vbus_dev,
+					       ci->platdata->edev->name, "USB",
+					       &ci->vbus_nb);
+		if (ret < 0)
+			dev_err(dev, "failed to register notifier for USB aka VBUS\n");
+
+		ci->id_nb.notifier_call = ci_id_notifier;
+		ret = extcon_register_interest(&ci->extcon_id_dev,
+					ci->platdata->edev->name, "USB-HOST",
+					&ci->id_nb);
+		if (ret < 0)
+			dev_err(dev, "failed to register notifier for USB-HOST aka ID\n");
+	}
+
 	if (ci->platdata->phy) {
 		ci->phy = ci->platdata->phy;
 	} else if (ci->platdata->usb_phy) {
@@ -922,7 +985,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 	ret = ci_usb_phy_init(ci);
 	if (ret) {
 		dev_err(dev, "unable to init phy: %d\n", ret);
-		return ret;
+		goto extcon_cleanup;
 	}
 
 	ci->hw_bank.phys = res->start;
@@ -964,10 +1027,28 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 		}
 	}
 
-	ci->role = ci_get_role(ci);
-	/* only update vbus status for peripheral */
-	if (ci->role == CI_ROLE_GADGET)
-		ci_handle_vbus_connected(ci);
+	if (ci->roles[CI_ROLE_HOST] && ci->roles[CI_ROLE_GADGET]) {
+		if (ci->is_otg) {
+			ci->role = ci_otg_role(ci);
+			/* Enable ID change irq */
+			hw_write_otgsc(ci, OTGSC_IDIE, OTGSC_IDIE);
+		} else {
+			/*
+			 * If the controller is not OTG capable, but support
+			 * role switch, the defalt role is gadget, and the
+			 * user can switch it through debugfs.
+			*/
+			if ((ci->platdata->edev) && (extcon_get_cable_state(
+				ci->platdata->edev, "USB-HOST") == true))
+				ci->role = CI_ROLE_HOST;
+			else
+				ci->role = CI_ROLE_GADGET;
+			}
+	} else {
+		ci->role = ci->roles[CI_ROLE_HOST]
+			? CI_ROLE_HOST
+			: CI_ROLE_GADGET;
+	}
 
 	if (!ci_otg_is_fsm_mode(ci)) {
 		ret = ci_role_start(ci, ci->role);
@@ -976,6 +1057,9 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 						ci_role(ci)->name);
 			goto stop;
 		}
+		if ((ci->role == CI_ROLE_GADGET) && (ci->platdata->edev) &&
+		    (extcon_get_cable_state(ci->platdata->edev, "USB") == true))
+			usb_gadget_vbus_connect(&ci->gadget);
 	}
 
 	platform_set_drvdata(pdev, ci);
@@ -1006,6 +1090,11 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 
 stop:
 	ci_role_destroy(ci);
+extcon_cleanup:
+	if (ci->extcon_vbus_dev.edev)
+		extcon_unregister_interest(&ci->extcon_vbus_dev);
+	if (ci->extcon_id_dev.edev)
+		extcon_unregister_interest(&ci->extcon_id_dev);
 deinit_phy:
 	ci_usb_phy_exit(ci);
 
@@ -1016,6 +1105,11 @@ static int ci_hdrc_remove(struct platform_device *pdev)
 {
 	struct ci_hdrc *ci = platform_get_drvdata(pdev);
 
+	if (ci->extcon_vbus_dev.edev)
+		extcon_unregister_interest(&ci->extcon_vbus_dev);
+	if (ci->extcon_id_dev.edev)
+		extcon_unregister_interest(&ci->extcon_id_dev);
+
 	if (ci->supports_runtime_pm) {
 		pm_runtime_get_sync(&pdev->dev);
 		pm_runtime_disable(&pdev->dev);
diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index fc9163946d75..b02deb0a7d7f 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h
@@ -52,6 +52,8 @@ struct ci_hdrc_platform_data {
 	struct regulator	*reg_vbus;
 	struct usb_otg_caps	ci_otg_caps;
 	bool			tpl_support;
+	struct extcon_dev	*edev;
+
 	/* interrupt threshold setting */
 	u32			itc_setting;
 	u32			ahb_burst_config;