Date:	Mon,  7 Sep 2015 14:45:25 +0300
From:	"Ivan T. Ivanov" <ivan.ivanov@...aro.org>
To:	Peter Chen <Peter.Chen@...escale.com>
Cc:	Rob Herring <robh+dt@...nel.org>, Pawel Moll <pawel.moll@....com>,
	Mark Rutland <mark.rutland@....com>,
	Ian Campbell <ijc+devicetree@...lion.org.uk>,
	Kumar Gala <galak@...eaurora.org>,
	Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
	Antoine Tenart <antoine.tenart@...e-electrons.com>,
	devicetree@...r.kernel.org, linux-kernel@...r.kernel.org,
	linux-usb@...r.kernel.org, linux-arm-msm@...r.kernel.org
Subject: [PATCH v4] usb: chipidea: Use extcon framework for VBUS and ID detect

On recent Qualcomm platforms VBUS and ID lines are not routed to
USB PHY LINK controller. Use extcon framework to receive connect
and disconnect ID and VBUS notification.

Signed-off-by: Ivan T. Ivanov <ivan.ivanov@...aro.org>
---

Changes sice v3 [1]:

* Migrate to new extcon framework API
* Address comments from Peter Chen.

Tested DRD role with "qcom,ci-hdrc" and "qcom,usb-8x16-phy" on DB410c

[1] https://lkml.org/lkml/2015/6/2/333

 .../devicetree/bindings/usb/ci-hdrc-usb2.txt       |   6 +
 drivers/usb/chipidea/Kconfig                       |   1 +
 drivers/usb/chipidea/core.c                        | 125 +++++++++++++++++++++
 drivers/usb/chipidea/otg.c                         |  39 ++++++-
 include/linux/usb/chipidea.h                       |  23 ++++
 5 files changed, 193 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
index d71ef07bca5d..aea7d0af5fd6 100644
--- a/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
+++ b/Documentation/devicetree/bindings/usb/ci-hdrc-usb2.txt
@@ -45,6 +45,11 @@ Optional properties:
   (4 bytes), This register represents the maximum length of a the burst
   in 32-bit words while moving data from the USB bus to system memory,
   changing this value takes effect only the SBUSCFG.AHBBRST is 0.
+- extcon: phandles to external connector devices. First phandle should point to
+  external connector, which provide "USB" cable events, the second should point
+  to external connector device, which provide "USB-HOST" cable events. If one
+  of the external connector devices is not required, empty <0> phandle should
+  be specified.

 Example:

@@ -61,4 +66,5 @@ Example:
 		ahb-burst-config = <0x0>;
 		tx-burst-size-dword = <0x10>; /* 64 bytes */
 		rx-burst-size-dword = <0x10>;
+		extcon = <0>, <&usb_id>;
 	};
diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
index 5ce3f1d6a6ed..5619b8ca3bf3 100644
--- a/drivers/usb/chipidea/Kconfig
+++ b/drivers/usb/chipidea/Kconfig
@@ -1,6 +1,7 @@
 config USB_CHIPIDEA
 	tristate "ChipIdea Highspeed Dual Role Controller"
 	depends on ((USB_EHCI_HCD && USB_GADGET) || (USB_EHCI_HCD && !USB_GADGET) || (!USB_EHCI_HCD && USB_GADGET)) && HAS_DMA
+	select EXTCON
 	help
 	  Say Y here if your system has a dual role high speed USB
 	  controller based on ChipIdea silicon IP. Currently, only the
diff --git a/drivers/usb/chipidea/core.c b/drivers/usb/chipidea/core.c
index 3feebf7f31f0..573c2876b263 100644
--- a/drivers/usb/chipidea/core.c
+++ b/drivers/usb/chipidea/core.c
@@ -47,6 +47,7 @@
 #include <linux/delay.h>
 #include <linux/device.h>
 #include <linux/dma-mapping.h>
+#include <linux/extcon.h>
 #include <linux/phy/phy.h>
 #include <linux/platform_device.h>
 #include <linux/module.h>
@@ -602,9 +603,45 @@ static irqreturn_t ci_irq(int irq, void *data)
 	return ret;
 }

+static int ci_vbus_notifier(struct notifier_block *nb, unsigned long event,
+			    void *ptr)
+{
+	struct ci_hdrc_cable *vbus = container_of(nb, struct ci_hdrc_cable, nb);
+	struct ci_hdrc *ci = vbus->ci;
+
+	if (event)
+		vbus->state = true;
+	else
+		vbus->state = false;
+
+	vbus->changed = true;
+
+	ci_irq(ci->irq, ci);
+	return NOTIFY_DONE;
+}
+
+static int ci_id_notifier(struct notifier_block *nb, unsigned long event,
+			  void *ptr)
+{
+	struct ci_hdrc_cable *id = container_of(nb, struct ci_hdrc_cable, nb);
+	struct ci_hdrc *ci = id->ci;
+
+	if (event)
+		id->state = false;
+	else
+		id->state = true;
+
+	id->changed = true;
+
+	ci_irq(ci->irq, ci);
+	return NOTIFY_DONE;
+}
+
 static int ci_get_platdata(struct device *dev,
 		struct ci_hdrc_platform_data *platdata)
 {
+	struct extcon_dev *ext_vbus, *ext_id;
+	struct ci_hdrc_cable *cable;
 	int ret;

 	if (!platdata->phy_mode)
@@ -695,9 +732,91 @@ static int ci_get_platdata(struct device *dev,
 		platdata->flags |= CI_HDRC_OVERRIDE_RX_BURST;
 	}

+	ext_id = ERR_PTR(-ENODEV);
+	ext_vbus = ERR_PTR(-ENODEV);
+	if (of_property_read_bool(dev->of_node, "extcon")) {
+		/* Each one of them is not mandatory */
+		ext_vbus = extcon_get_edev_by_phandle(dev, 0);
+		if (IS_ERR(ext_vbus) && PTR_ERR(ext_vbus) != -ENODEV)
+			return PTR_ERR(ext_vbus);
+
+		ext_id = extcon_get_edev_by_phandle(dev, 1);
+		if (IS_ERR(ext_id) && PTR_ERR(ext_id) != -ENODEV)
+			return PTR_ERR(ext_id);
+	}
+
+	cable = &platdata->vbus_extcon;
+	cable->nb.notifier_call = ci_vbus_notifier;
+	cable->edev = ext_vbus;
+
+	if (!IS_ERR(ext_vbus)) {
+		ret = extcon_get_cable_state_(cable->edev, EXTCON_USB);
+		if (ret)
+			cable->state = true;
+		else
+			cable->state = false;
+	}
+
+	cable = &platdata->id_extcon;
+	cable->nb.notifier_call = ci_id_notifier;
+	cable->edev = ext_id;
+
+	if (!IS_ERR(ext_id)) {
+		ret = extcon_get_cable_state_(cable->edev, EXTCON_USB_HOST);
+		if (ret)
+			cable->state = false;
+		else
+			cable->state = true;
+	}
 	return 0;
 }

+static int ci_extcon_register(struct ci_hdrc *ci)
+{
+	struct ci_hdrc_cable *id, *vbus;
+	int ret;
+
+	id = &ci->platdata->id_extcon;
+	id->ci = ci;
+	if (!IS_ERR(id->edev)) {
+		ret = extcon_register_notifier(id->edev, EXTCON_USB_HOST,
+					       &id->nb);
+		if (ret < 0) {
+			dev_err(ci->dev, "register ID failed\n");
+			return ret;
+		}
+	}
+
+	vbus = &ci->platdata->vbus_extcon;
+	vbus->ci = ci;
+	if (!IS_ERR(vbus->edev)) {
+		ret = extcon_register_notifier(vbus->edev, EXTCON_USB,
+					       &vbus->nb);
+		if (ret < 0) {
+			extcon_unregister_notifier(id->edev, EXTCON_USB_HOST,
+						   &id->nb);
+			dev_err(ci->dev, "register VBUS failed\n");
+			return ret;
+		}
+	}
+
+	return 0;
+}
+
+static void ci_extcon_unregister(struct ci_hdrc *ci)
+{
+	struct ci_hdrc_cable *cable;
+
+	cable = &ci->platdata->id_extcon;
+	if (!IS_ERR(cable->edev))
+		extcon_unregister_notifier(cable->edev, EXTCON_USB_HOST,
+					   &cable->nb);
+
+	cable = &ci->platdata->vbus_extcon;
+	if (!IS_ERR(cable->edev))
+		extcon_unregister_notifier(cable->edev, EXTCON_USB, &cable->nb);
+}
+
 static DEFINE_IDA(ci_ida);

 struct platform_device *ci_hdrc_add_device(struct device *dev,
@@ -921,6 +1040,10 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 	if (ret)
 		goto stop;

+	ret = ci_extcon_register(ci);
+	if (ret)
+		goto stop;
+
 	if (ci->supports_runtime_pm) {
 		pm_runtime_set_active(&pdev->dev);
 		pm_runtime_enable(&pdev->dev);
@@ -938,6 +1061,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
 	if (!ret)
 		return 0;

+	ci_extcon_unregister(ci);
 stop:
 	ci_role_destroy(ci);
 deinit_phy:
@@ -957,6 +1081,7 @@ static int ci_hdrc_remove(struct platform_device *pdev)
 	}

 	dbg_remove_files(ci);
+	ci_extcon_unregister(ci);
 	ci_role_destroy(ci);
 	ci_hdrc_enter_lpm(ci, true);
 	ci_usb_phy_exit(ci);
diff --git a/drivers/usb/chipidea/otg.c b/drivers/usb/chipidea/otg.c
index ad6c87a4653c..ab4bd0c2d4ef 100644
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c
@@ -30,7 +30,44 @@
  */
 u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
 {
-	return hw_read(ci, OP_OTGSC, mask);
+	struct ci_hdrc_cable *cable;
+	u32 val = hw_read(ci, OP_OTGSC, mask);
+
+	/*
+	 * If using extcon framework for VBUS and/or ID signal
+	 * detection overwrite OTGSC register value
+	 */
+	cable = &ci->platdata->vbus_extcon;
+	if (!IS_ERR(cable->edev)) {
+		if (cable->changed)
+			val |= OTGSC_BSVIS;
+		else
+			val &= ~OTGSC_BSVIS;
+
+		cable->changed = false;
+
+		if (cable->state)
+			val |= OTGSC_BSV;
+		else
+			val &= ~OTGSC_BSV;
+	}
+
+	cable = &ci->platdata->id_extcon;
+	if (!IS_ERR(cable->edev)) {
+		if (cable->changed)
+			val |= OTGSC_IDIS;
+		else
+			val &= ~OTGSC_IDIS;
+
+		cable->changed = false;
+
+		if (cable->state)
+			val |= OTGSC_ID;
+		else
+			val &= ~OTGSC_ID;
+	}
+
+	return val;
 }

 /**
diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index a41833cd184c..c5cddc6901d0 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h
@@ -5,9 +5,28 @@
 #ifndef __LINUX_USB_CHIPIDEA_H
 #define __LINUX_USB_CHIPIDEA_H

+#include <linux/extcon.h>
 #include <linux/usb/otg.h>

 struct ci_hdrc;
+
+/**
+ * struct ci_hdrc_cable - structure for external connector cable state tracking
+ * @state: current state of the line
+ * @changed: set to true when extcon event happen
+ * @edev: device which generate events
+ * @ci: driver state of the chipidea device
+ * @nb: hold event notification callback
+ * @conn: used for notification registration
+ */
+struct ci_hdrc_cable {
+	bool				state;
+	bool				changed;
+	struct extcon_dev		*edev;
+	struct ci_hdrc			*ci;
+	struct notifier_block		nb;
+};
+
 struct ci_hdrc_platform_data {
 	const char	*name;
 	/* offset of the capability registers */
@@ -48,6 +67,10 @@ struct ci_hdrc_platform_data {
 	u32			ahb_burst_config;
 	u32			tx_burst_size;
 	u32			rx_burst_size;
+
+	/* VBUS and ID signal state tracking, using extcon framework */
+	struct ci_hdrc_cable		vbus_extcon;
+	struct ci_hdrc_cable		id_extcon;
 };

 /* Default offset of capability registers */
--
1.9.1

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