diff mbox

[v3] usb: chipidea: Use extcon framework for VBUS and ID detect

Message ID 1433250873-20780-1-git-send-email-ivan.ivanov@linaro.org
State New
Headers show

Commit Message

Ivan T. Ivanov June 2, 2015, 1:14 p.m. UTC 
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@linaro.org>
---
Changes sice v2 [1].

* Simulate IRQ on extcon event - used to trigger OTG state machine.

I have to admit that I couldn't test complete Chipidea OTG state machine,
because my setup is little weird. I am using "qcom,usb-otg-ci" as PHY/OTG
provider, "qcom,ehci-host" as host controller driver and "qcom,ci-hdrc" for
device role.

There could be patch conflict regarding ci-hdrc-qcom.txt, because Rob Herring
is consolidating DT binding for all vendors which integrate this device [2]

[1] https://lkml.org/lkml/2015/4/15/283
[2] http://www.spinics.net/lists/linux-usb/msg125453.html

 .../devicetree/bindings/usb/ci-hdrc-qcom.txt       |   9 ++
 drivers/usb/chipidea/Kconfig                       |   1 +
 drivers/usb/chipidea/core.c                        | 125 +++++++++++++++++++++
 drivers/usb/chipidea/otg.c                         |  55 ++++++++-
 include/linux/usb/chipidea.h                       |  24 ++++
 5 files changed, 212 insertions(+), 2 deletions(-)

--
1.9.1

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Comments

Ivan T. Ivanov June 5, 2015, 7:37 a.m. UTC | #1 
On Fri, 2015-06-05 at 15:03 +0800, Peter Chen wrote:
> On Tue, Jun 02, 2015 at 04:14:33PM +0300, Ivan T. Ivanov wrote:
> > 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 ivanov@linaro.org>
> > ---
> > Changes sice v2 [1].
> > 
> > * Simulate IRQ on extcon event - used to trigger OTG state machine.
> > 
> 
> No, you may not need to trigger complicate OTG FSM, instead, the
> role switch based on ID value is ok.

I have tried this also, but I decided that using IRQ simulation
will handle all use cases.

> 
> > I have to admit that I couldn't test complete Chipidea OTG state machine,
> > because my setup is little weird. I am using "qcom,usb-otg-ci" as PHY/OTG
> > provider, "qcom,ehci-host" as host controller driver and "qcom,ci-hdrc" for
> > device role.
> > 
> 
> Then, I am puzzled what kinds of flow you have tested in this patch?
> extcon is really needed for chipidea core, but I hope we have tested
> patch set based on it. Rob Herring have tested Marvell's host controller
> can also use chipidea host driver, I think the same for qualcomm's.
> The otg flow at phy-msm-usb.c can be removed and use chipidea's instead, and
> only remain phy part at it.

I have tried this, but there is too many legacy code which is supposed to 
handle old platforms and I can not distinguish, which should stay in and
what could be taken out. I will take a look again. 

> 
> Current role switch and vbus flow are based on otgsc register, you can
> improve it by adding extcon support.

I am not sure that I get this. Isn't exactly what this patch does?

Regards,
Ivan

> 
> Peter
> 
> > There could be patch conflict regarding ci-hdrc-qcom.txt, because Rob Herring
> > is consolidating DT binding for all vendors which integrate this device [2]
> > 
> > [1] https://lkml.org/lkml/2015/4/15/283
> > [2] http://www.spinics.net/lists/linux-usb/msg125453.html
> > 
> >  .../devicetree/bindings/usb/ci-hdrc-qcom.txt       |   9 ++
> >  drivers/usb/chipidea/Kconfig                       |   1 +
> >  drivers/usb/chipidea/core.c                        | 125 +++++++++++++++++++++
> >  drivers/usb/chipidea/otg.c                         |  55 ++++++++-
> >  include/linux/usb/chipidea.h                       |  24 ++++
> >  5 files changed, 212 insertions(+), 2 deletions(-)
> > 
> > diff --git a/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt b/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt
> > index f2899b5..c635aca 100644
> > --- a/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt
> > +++ b/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt
> > @@ -7,6 +7,14 @@ Required properties:
> >  - usb-phy:      phandle for the PHY device
> >  - dr_mode:      Should be "peripheral"
> > 
> > +Optional properties:
> > +- 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.
> > +
> >  Examples:
> >        gadget@f9a55000 {
> >                 compatible = "qcom,ci-hdrc";
> > @@ -14,4 +22,5 @@ Examples:
> >                 dr_mode = "peripheral";
> >                 interrupts = <0 134 0>;
> >                 usb-phy = <&usbphy0>;
> > +               extcon = <0>, <&usb_id>;
> >         };
> > diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
> > index 5ce3f1d..5619b8c 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 74fea4f..2ae2c09 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>
> > @@ -557,9 +558,47 @@ 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)
> >                 platdata->phy_mode = of_usb_get_phy_mode(dev->of_node);
> > 
> > @@ -591,9 +630,89 @@ static int ci_get_platdata(struct device *dev,
> >         if (of_usb_get_maximum_speed(dev->of_node) == USB_SPEED_FULL)
> >                 platdata->flags |= CI_HDRC_FORCE_FULLSPEED;
> > 
> > +       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, "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, "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_interest(&id->conn, id->edev->name,
> > +                                                                                               "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_interest(&vbus->conn, vbus->edev->name,
> > +                                                                                               "USB", &vbus->nb);
> > +               if (ret < 0) {
> > +                       extcon_unregister_interest(&id->conn);
> > +                       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_interest(&cable->conn);
> > +
> > +       cable = &ci->platdata->vbus_extcon;
> > +       if (!IS_ERR(cable->edev))
> > +               extcon_unregister_interest(&cable->conn);
> > +}
> > +
> >  static DEFINE_IDA(ci_ida);
> > 
> >  struct platform_device *ci_hdrc_add_device(struct device *dev,
> > @@ -817,6 +936,10 @@ 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);
> > @@ -834,6 +957,7 @@ static int ci_hdrc_probe(struct platform_device *pdev)
> >         if (!ret)
> >                 return 0;
> > 
> > +       ci_extcon_unregister(ci);
> >  stop:
> >         ci_role_destroy(ci);
> >  deinit_phy:
> > @@ -853,6 +977,7 @@ 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 ad6c87a..77fe2df 100644
> > --- a/drivers/usb/chipidea/otg.c
> > +++ b/drivers/usb/chipidea/otg.c
> > @@ -30,7 +30,41 @@
> >   */
> >  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 resiter value
> > +               */
> > +       cable = &ci->platdata->vbus_extcon;
> > +       if (!IS_ERR(cable->edev)) {
> > +               if (cable->changed)
> > +                       val |= OTGSC_BSVIS;
> > +               else
> > +                       val &= ~OTGSC_BSVIS;
> > +
> > +               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;
> > +
> > +               if (cable->state)
> > +                       val |= OTGSC_ID;
> > +               else
> > +                       val &= ~OTGSC_ID;
> > +       }
> > +
> > +       val &= mask;
> > +       return val;
> >  }
> > 
> >  /**
> > @@ -40,7 +74,24 @@ u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
> >   */
> >  void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
> >  {
> > -       hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
> > +       struct ci_hdrc_cable *cable;
> > +
> > +       mask |= OTGSC_INT_STATUS_BITS;
> > +
> > +       /* clear artificial bits */
> > +       cable = &ci->platdata->vbus_extcon;
> > +       if (!IS_ERR(cable->edev)) {
> > +               if (data & OTGSC_BSVIS)
> > +                       cable->changed = false;
> > +       }
> > +
> > +       cable = &ci->platdata->id_extcon;
> > +       if (!IS_ERR(cable->edev)) {
> > +               if (data & OTGSC_IDIS)
> > +                       cable->changed = false;
> > +       }
> > +
> > +       hw_write(ci, OP_OTGSC, mask, data);
> >  }
> > 
> >  /**
> > diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
> > index ab94f78..05915cb1 100644
> > --- a/include/linux/usb/chipidea.h
> > +++ b/include/linux/usb/chipidea.h
> > @@ -5,9 +5,29 @@
> >  #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_blocknb;
> > +       struct extcon_specific_cable_nb conn;
> > +};
> > +
> >  struct ci_hdrc_platform_data {
> >         const char*name;
> >         /* offset of the capability registers */
> > @@ -35,6 +55,10 @@ struct ci_hdrc_platform_data {
> >         void    (*notify_event) (struct ci_hdrc *ci, unsigned event);
> >         struct regulator*reg_vbus;
> >         bool    tpl_support;
> > +
> > +       /* VBUS and ID signal state tracking, using extcon framework */
> > +       struct ci_hdrc_cablevbus_extcon;
> > +       struct ci_hdrc_cableid_extcon;
> >  };
> > 
> >  /* Default offset of capability registers */
> > --
> > 1.9.1
> > 
> 
> 
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Ivan T. Ivanov Sept. 7, 2015, 11:45 a.m. UTC | #2 
On Fri, 2015-06-05 at 17:26 +0800, Peter Chen wrote:
> On Fri, Jun 05, 2015 at 10:37:07AM +0300, Ivan T. Ivanov wrote:

<snip>

> 
> > > > +
> > > > +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;
> > > > +
> 
> How to know the id value must be changed?
> How about using id->changed = (event != id->state) ? true : false?
> of cos, it needs to move before if {}.

This is handled already by extcon framework.

> 
> The same change may need to add to vbus notifier.
> 
> > > > +       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)
> > > >                 platdata->phy_mode = of_usb_get_phy_mode(dev->of_node);
> > > > 
> > > > @@ -591,9 +630,89 @@ static int ci_get_platdata(struct device *dev,
> > > >         if (of_usb_get_maximum_speed(dev->of_node) == USB_SPEED_FULL)
> > > >                 platdata->flags |= CI_HDRC_FORCE_FULLSPEED;
> > > > 
> > > > +       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, "USB");
> 
> I have not read extcon framework too much, but seems you should only
> can get cable state after register it (through ci_extcon_register)?
> ci_get_platdata is called before ci core probe.

No that is not a problem, you can always read cable state if you have
reference to extcon device.

Will fix remaining comments in next version.

Regards,
Ivan
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diff mbox

Patch

diff --git a/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt b/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt
index f2899b5..c635aca 100644
--- a/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt
+++ b/Documentation/devicetree/bindings/usb/ci-hdrc-qcom.txt
@@ -7,6 +7,14 @@  Required properties:
 - usb-phy:      phandle for the PHY device
 - dr_mode:      Should be "peripheral"

+Optional properties:
+- 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.
+
 Examples:
 	gadget@f9a55000 {
 		compatible = "qcom,ci-hdrc";
@@ -14,4 +22,5 @@  Examples:
 		dr_mode = "peripheral";
 		interrupts = <0 134 0>;
 		usb-phy = <&usbphy0>;
+		extcon = <0>, <&usb_id>;
 	};
diff --git a/drivers/usb/chipidea/Kconfig b/drivers/usb/chipidea/Kconfig
index 5ce3f1d..5619b8c 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 74fea4f..2ae2c09 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>
@@ -557,9 +558,47 @@  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)
 		platdata->phy_mode = of_usb_get_phy_mode(dev->of_node);

@@ -591,9 +630,89 @@  static int ci_get_platdata(struct device *dev,
 	if (of_usb_get_maximum_speed(dev->of_node) == USB_SPEED_FULL)
 		platdata->flags |= CI_HDRC_FORCE_FULLSPEED;

+	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, "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, "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_interest(&id->conn, id->edev->name,
+					       "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_interest(&vbus->conn, vbus->edev->name,
+					       "USB", &vbus->nb);
+		if (ret < 0) {
+			extcon_unregister_interest(&id->conn);
+			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_interest(&cable->conn);
+
+	cable = &ci->platdata->vbus_extcon;
+	if (!IS_ERR(cable->edev))
+		extcon_unregister_interest(&cable->conn);
+}
+
 static DEFINE_IDA(ci_ida);

 struct platform_device *ci_hdrc_add_device(struct device *dev,
@@ -817,6 +936,10 @@  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);
@@ -834,6 +957,7 @@  static int ci_hdrc_probe(struct platform_device *pdev)
 	if (!ret)
 		return 0;

+	ci_extcon_unregister(ci);
 stop:
 	ci_role_destroy(ci);
 deinit_phy:
@@ -853,6 +977,7 @@  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 ad6c87a..77fe2df 100644
--- a/drivers/usb/chipidea/otg.c
+++ b/drivers/usb/chipidea/otg.c
@@ -30,7 +30,41 @@ 
  */
 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 resiter value
+	 */
+	cable = &ci->platdata->vbus_extcon;
+	if (!IS_ERR(cable->edev)) {
+		if (cable->changed)
+			val |= OTGSC_BSVIS;
+		else
+			val &= ~OTGSC_BSVIS;
+
+		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;
+
+		if (cable->state)
+			val |= OTGSC_ID;
+		else
+			val &= ~OTGSC_ID;
+	}
+
+	val &= mask;
+	return val;
 }

 /**
@@ -40,7 +74,24 @@  u32 hw_read_otgsc(struct ci_hdrc *ci, u32 mask)
  */
 void hw_write_otgsc(struct ci_hdrc *ci, u32 mask, u32 data)
 {
-	hw_write(ci, OP_OTGSC, mask | OTGSC_INT_STATUS_BITS, data);
+	struct ci_hdrc_cable *cable;
+
+	mask |= OTGSC_INT_STATUS_BITS;
+
+	/* clear artificial bits */
+	cable = &ci->platdata->vbus_extcon;
+	if (!IS_ERR(cable->edev)) {
+		if (data & OTGSC_BSVIS)
+			cable->changed = false;
+	}
+
+	cable = &ci->platdata->id_extcon;
+	if (!IS_ERR(cable->edev)) {
+		if (data & OTGSC_IDIS)
+			cable->changed = false;
+	}
+
+	hw_write(ci, OP_OTGSC, mask, data);
 }

 /**
diff --git a/include/linux/usb/chipidea.h b/include/linux/usb/chipidea.h
index ab94f78..05915cb1 100644
--- a/include/linux/usb/chipidea.h
+++ b/include/linux/usb/chipidea.h
@@ -5,9 +5,29 @@ 
 #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 extcon_specific_cable_nb conn;
+};
+
 struct ci_hdrc_platform_data {
 	const char	*name;
 	/* offset of the capability registers */
@@ -35,6 +55,10 @@  struct ci_hdrc_platform_data {
 	void	(*notify_event) (struct ci_hdrc *ci, unsigned event);
 	struct regulator	*reg_vbus;
 	bool			tpl_support;
+
+	/* 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 */