[PATCH 0/3] usb: phy: hold wakeupsource on usb phy events.

[PATCH 0/3] usb: phy: hold wakeupsource on usb phy events.

[Kiran Kumar Raparthy]

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This patch set aims to hold wakeupsource per-PHY on usb connect/disconnect
events.

First patch introduces usb_phy_set_event which just sets
event to phy event.
In second patch, phy drivers call usb_phy_set_event for each phy event.
In third patch, wakeupsource is held when usb is enumerated in
peripheral mode and wakeupsource held temporarily on disconnect
event(to allow other parts of the system react to disconnect event).

latest patch-set:
* use USB_PHY_DEFAULT_WAKEUP_SRC_TIMEOUT instead of TEMPORARY_HOLD_TIME

v6:
* Break the patch into three sub patches
  patch 1: Introduce usb_phy_set_event
  patch 2: Call usb_phy_set_event from phy drivers
  patch 3: Hold wakeupsource for connect events and
            temporarily hold wakeupsource for disconnect events.
* Include usb_phy_wsource_init and usb_phy_wource_trash functionality
  in usb_add_phy and usb_remove_phy respectively.

v5:
* with the new approach,i was able to chnage only 5 phy drivers
  as mentioned below to use the wakeupsource funtionality.

drivers/phy/phy-omap-control.c
drivers/usb/phy/phy-ab8500-usb.c
drivers/usb/phy/phy-tahvo.c
drivers/usb/phy/phy-mv-usb.c
drivers/usb/phy/phy-gpio-vbus-usb.c

* Notification method not used any more.
* introduced usb_phy_set_event in phy.c to hold wakeupsource
* introduced usb_phy_wsource_init/usb_phy_wsource_trash in phy.c to
  initialize/relese per-PHY wakeupsource.These interfaces called from
  probe/remove functions of phy drivers.
* usb_phy_set_event called from phy drivers where usb enumeration
  event is handled.
* usb_phy_set_event expects usb_phy handle where as phy-omap-control.c
  provides its own type(omap_control_phy), so directly called __pm_stay_awake
  and  __pm_awake_event from phy-omap-control.c instead of calling
  usb_phy_set_event.

v4:
* Temporarily hold wakeupsource patch integrated into main patch.
* As per feedback,dropped "enabled" module parameter.
* Introduced otgws_otg_usb3_notifications function to handle event
  notifications from usb3 phy.
* Handled wakeupsource initialization,spinlock,registration of notifier block
  per-PHY.
* Updated usb_phy structure.

v3:
* As per the feedback,no global phy pointer used.
* called the one-liner wakeupsource handling calls
  directly instead of indirect functions implemented in v2.
* Removed indirect function get_phy_hook and used usb_get_phy
  to get the phy handle..

v2:
* wakeupsource handling implemeted per-PHY
* Implemented wakeupsource handling calls in phy
* included Todd's refactoring logic.

v1:
* changed to "disabled by default" from "enable by default".
* Kconfig help text modified
* Included better commit text
* otgws_nb moved to otg_wakeupsource_init function
* Introduced get_phy_hook to handle otgws_xceiv per-PHY

Initial RFC:
* Included build fix from Benoit Goby and Arve Hjønnevåg
* Removed lock->held field in driver as this mechanism is
  provided in wakeupsource driver.
* wakelock(wl) terminology replaced with wakeup_source(ws).

Todd Poynor (3):
  usb: phy: introduce usb_phy_set_event interface
  usb: phy: Handle per-PHY event for connect and disconnect events
  usb: phy: hold wakeupsource when USB is enumerated in peripheral mode

 drivers/usb/phy/phy-ab8500-usb.c    | 15 +++++++++++++++
 drivers/usb/phy/phy-gpio-vbus-usb.c |  2 ++
 drivers/usb/phy/phy-mv-usb.c        |  2 ++
 drivers/usb/phy/phy-tahvo.c         |  2 ++
 drivers/usb/phy/phy.c               | 37 +++++++++++++++++++++++++++++++++++++
 include/linux/usb/phy.h             | 10 ++++++++++
 6 files changed, 68 insertions(+)

-- 
1.8.2.1

[PATCH 1/3] usb: phy: introduce usb_phy_set_event interface

[Kiran Kumar Raparthy]

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From: Todd Poynor <toddpoynor@google.com>

usb: phy: introduce usb_phy_set_event interface

PHY drivers require a generic interface to handle per-PHY events.

usb_phy_set_event interface sets event to phy event.
PHY drivers call this interface for each phy event.

Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: Android Kernel Team <kernel-team@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Benoit Goby <benoit@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
[kiran: Added context to commit message, squished build fixes
from Benoit Goby and Arve Hjønnevåg, changed wakelocks usage
to wakeupsource, merged Todd's refactoring logic and simplified
the structures and code and addressed community feedback]
Signed-off-by: Kiran Raparthy <kiran.kumar@linaro.org>
---
 drivers/usb/phy/phy.c   | 12 ++++++++++++
 include/linux/usb/phy.h |  5 +++++
 2 files changed, 17 insertions(+)

diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c
index 045cd30..2b1039e 100644
--- a/drivers/usb/phy/phy.c
+++ b/drivers/usb/phy/phy.c
@@ -444,3 +444,15 @@ int usb_bind_phy(const char *dev_name, u8 index,
 	return 0;
 }
 EXPORT_SYMBOL_GPL(usb_bind_phy);
+
+/**
+ * usb_phy_set_event - set event to phy event
+ * @x: the phy returned by usb_get_phy();
+ *
+ * This sets event to phy event
+ */
+void usb_phy_set_event(struct usb_phy *x, unsigned long event)
+{
+	x->last_event = event;
+}
+EXPORT_SYMBOL_GPL(usb_phy_set_event);
diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index 353053a..3c713ff 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -210,6 +210,7 @@ extern void usb_put_phy(struct usb_phy *);
 extern void devm_usb_put_phy(struct device *dev, struct usb_phy *x);
 extern int usb_bind_phy(const char *dev_name, u8 index,
 				const char *phy_dev_name);
+extern void usb_phy_set_event(struct usb_phy *x, unsigned long event);
 #else
 static inline struct usb_phy *usb_get_phy(enum usb_phy_type type)
 {
@@ -251,6 +252,10 @@ static inline int usb_bind_phy(const char *dev_name, u8 index,
 {
 	return -EOPNOTSUPP;
 }
+
+static inline void usb_phy_set_event(struct usb_phy *x, unsigned long event)
+{
+}
 #endif
 
 static inline int
-- 
1.8.2.1

Re: [PATCH 1/3] usb: phy: introduce usb_phy_set_event interface

[Todd Poynor]

On Wed, Nov 19, 2014 at 2:43 AM, Kiran Kumar Raparthy
<kiran.kumar@linaro.org> wrote:
> From: Todd Poynor <toddpoynor@google.com>
>
> usb: phy: introduce usb_phy_set_event interface

Hi Kiran, this is new stuff that is all your own work and you deserve
the credit.

Thanks for working to get this feature in shape for mainline!


Todd

Re: [PATCH 1/3] usb: phy: introduce usb_phy_set_event interface

[Felipe Balbi]

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On Wed, Nov 19, 2014 at 08:36:22AM -0800, Todd Poynor wrote:
> On Wed, Nov 19, 2014 at 2:43 AM, Kiran Kumar Raparthy
> <kiran.kumar@linaro.org> wrote:
> > From: Todd Poynor <toddpoynor@google.com>
> >
> > usb: phy: introduce usb_phy_set_event interface
> 
> Hi Kiran, this is new stuff that is all your own work and you deserve
> the credit.
> 
> Thanks for working to get this feature in shape for mainline!

Kiran, what Todd is saying is that $subject is From: Kiran, do you want
to resend with that change ? I think this is ready to be moved into my
testing/next otherwise.

-- 
balbi

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Re: [PATCH 1/3] usb: phy: introduce usb_phy_set_event interface

[Kiran Raparthy]

Hi Felipe,
On 21 November 2014 01:24, Felipe Balbi <balbi@ti.com> wrote:
> On Wed, Nov 19, 2014 at 08:36:22AM -0800, Todd Poynor wrote:
>> On Wed, Nov 19, 2014 at 2:43 AM, Kiran Kumar Raparthy
>> <kiran.kumar@linaro.org> wrote:
>> > From: Todd Poynor <toddpoynor@google.com>
>> >
>> > usb: phy: introduce usb_phy_set_event interface
>>
>> Hi Kiran, this is new stuff that is all your own work and you deserve
>> the credit.
>>
>> Thanks for working to get this feature in shape for mainline!
>
> Kiran, what Todd is saying is that $subject is From: Kiran, do you want
> to resend with that change ? I think this is ready to be moved into my
> testing/next otherwise.
I thanked him for his kind words.
No issues,I prefer not bothering you again by sending one more set of patches.
Please accept them if you feel the patches are good in shape.
Thank you so much for your time and support.
Regards,
Kiran

>
> --
> balbi

[PATCH 2/3] usb: phy: Handle per-PHY event for connect and disconnect events

[Kiran Kumar Raparthy]

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From: Todd Poynor <toddpoynor@google.com>

usb: phy: Handle per-PHY event for connnect and disconnect events

When usb is connected and enumerated in device mode or when usb is
disconnected,call usb_phy_set_event from phy drivers to handle per-PHY event.

Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: Android Kernel Team <kernel-team@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Benoit Goby <benoit@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
[kiran: Added context to commit message, squished build fixes
from Benoit Goby and Arve Hjønnevåg, changed wakelocks usage
to wakeupsource, merged Todd's refactoring logic and simplified
the structures and code and addressed community feedback]
Signed-off-by: Kiran Raparthy <kiran.kumar@linaro.org>
---
 drivers/usb/phy/phy-ab8500-usb.c    | 15 +++++++++++++++
 drivers/usb/phy/phy-gpio-vbus-usb.c |  2 ++
 drivers/usb/phy/phy-mv-usb.c        |  2 ++
 drivers/usb/phy/phy-tahvo.c         |  2 ++
 4 files changed, 21 insertions(+)

diff --git a/drivers/usb/phy/phy-ab8500-usb.c b/drivers/usb/phy/phy-ab8500-usb.c
index 11ab2c4..d79fa3e 100644
--- a/drivers/usb/phy/phy-ab8500-usb.c
+++ b/drivers/usb/phy/phy-ab8500-usb.c
@@ -447,6 +447,7 @@ static int ab9540_usb_link_status_update(struct ab8500_usb *ab,
 			event = UX500_MUSB_NONE;
 		/* Fallback to default B_IDLE as nothing is connected. */
 		ab->phy.state = OTG_STATE_B_IDLE;
+		usb_phy_set_event(&ab->phy, USB_EVENT_NONE);
 		break;
 
 	case USB_LINK_ACA_RID_C_NM_9540:
@@ -461,12 +462,14 @@ static int ab9540_usb_link_status_update(struct ab8500_usb *ab,
 			ab8500_usb_peri_phy_en(ab);
 			atomic_notifier_call_chain(&ab->phy.notifier,
 					UX500_MUSB_PREPARE, &ab->vbus_draw);
+			usb_phy_set_event(&ab->phy, USB_EVENT_ENUMERATED);
 		}
 		if (ab->mode == USB_IDLE) {
 			ab->mode = USB_PERIPHERAL;
 			ab8500_usb_peri_phy_en(ab);
 			atomic_notifier_call_chain(&ab->phy.notifier,
 					UX500_MUSB_PREPARE, &ab->vbus_draw);
+			usb_phy_set_event(&ab->phy, USB_EVENT_ENUMERATED);
 		}
 		if (event != UX500_MUSB_RIDC)
 			event = UX500_MUSB_VBUS;
@@ -502,6 +505,7 @@ static int ab9540_usb_link_status_update(struct ab8500_usb *ab,
 		event = UX500_MUSB_CHARGER;
 		atomic_notifier_call_chain(&ab->phy.notifier,
 				event, &ab->vbus_draw);
+		usb_phy_set_event(&ab->phy, USB_EVENT_CHARGER);
 		break;
 
 	case USB_LINK_PHYEN_NO_VBUS_NO_IDGND_9540:
@@ -526,6 +530,7 @@ static int ab9540_usb_link_status_update(struct ab8500_usb *ab,
 				ab->mode = USB_IDLE;
 				ab->phy.otg->default_a = false;
 				ab->vbus_draw = 0;
+				usb_phy_set_event(&ab->phy, USB_EVENT_NONE);
 			}
 		}
 		break;
@@ -585,6 +590,7 @@ static int ab8540_usb_link_status_update(struct ab8500_usb *ab,
 		 * is connected
 		 */
 		ab->phy.state = OTG_STATE_B_IDLE;
+		usb_phy_set_event(&ab->phy, USB_EVENT_NONE);
 		break;
 
 	case USB_LINK_ACA_RID_C_NM_8540:
@@ -598,6 +604,7 @@ static int ab8540_usb_link_status_update(struct ab8500_usb *ab,
 			ab8500_usb_peri_phy_en(ab);
 			atomic_notifier_call_chain(&ab->phy.notifier,
 					UX500_MUSB_PREPARE, &ab->vbus_draw);
+			usb_phy_set_event(&ab->phy, USB_EVENT_ENUMERATED);
 		}
 		if (event != UX500_MUSB_RIDC)
 			event = UX500_MUSB_VBUS;
@@ -626,6 +633,7 @@ static int ab8540_usb_link_status_update(struct ab8500_usb *ab,
 		event = UX500_MUSB_CHARGER;
 		atomic_notifier_call_chain(&ab->phy.notifier,
 				event, &ab->vbus_draw);
+		usb_phy_set_event(&ab->phy, USB_EVENT_CHARGER);
 		break;
 
 	case USB_LINK_PHYEN_NO_VBUS_NO_IDGND_8540:
@@ -648,6 +656,7 @@ static int ab8540_usb_link_status_update(struct ab8500_usb *ab,
 			ab->mode = USB_IDLE;
 			ab->phy.otg->default_a = false;
 			ab->vbus_draw = 0;
+		usb_phy_set_event(&ab->phy, USB_EVENT_NONE);
 		}
 		break;
 
@@ -694,6 +703,7 @@ static int ab8505_usb_link_status_update(struct ab8500_usb *ab,
 		 * is connected
 		 */
 		ab->phy.state = OTG_STATE_B_IDLE;
+		usb_phy_set_event(&ab->phy, USB_EVENT_NONE);
 		break;
 
 	case USB_LINK_ACA_RID_C_NM_8505:
@@ -707,6 +717,7 @@ static int ab8505_usb_link_status_update(struct ab8500_usb *ab,
 			ab8500_usb_peri_phy_en(ab);
 			atomic_notifier_call_chain(&ab->phy.notifier,
 					UX500_MUSB_PREPARE, &ab->vbus_draw);
+			usb_phy_set_event(&ab->phy, USB_EVENT_ENUMERATED);
 		}
 		if (event != UX500_MUSB_RIDC)
 			event = UX500_MUSB_VBUS;
@@ -734,6 +745,7 @@ static int ab8505_usb_link_status_update(struct ab8500_usb *ab,
 		event = UX500_MUSB_CHARGER;
 		atomic_notifier_call_chain(&ab->phy.notifier,
 				event, &ab->vbus_draw);
+		usb_phy_set_event(&ab->phy, USB_EVENT_CHARGER);
 		break;
 
 	default:
@@ -777,6 +789,7 @@ static int ab8500_usb_link_status_update(struct ab8500_usb *ab,
 			event = UX500_MUSB_NONE;
 		/* Fallback to default B_IDLE as nothing is connected */
 		ab->phy.state = OTG_STATE_B_IDLE;
+		usb_phy_set_event(&ab->phy, USB_EVENT_NONE);
 		break;
 
 	case USB_LINK_ACA_RID_C_NM_8500:
@@ -794,6 +807,7 @@ static int ab8500_usb_link_status_update(struct ab8500_usb *ab,
 			ab8500_usb_peri_phy_en(ab);
 			atomic_notifier_call_chain(&ab->phy.notifier,
 					UX500_MUSB_PREPARE, &ab->vbus_draw);
+			usb_phy_set_event(&ab->phy, USB_EVENT_ENUMERATED);
 		}
 		if (event != UX500_MUSB_RIDC)
 			event = UX500_MUSB_VBUS;
@@ -820,6 +834,7 @@ static int ab8500_usb_link_status_update(struct ab8500_usb *ab,
 		event = UX500_MUSB_CHARGER;
 		atomic_notifier_call_chain(&ab->phy.notifier,
 				event, &ab->vbus_draw);
+		usb_phy_set_event(&ab->phy, USB_EVENT_CHARGER);
 		break;
 
 	case USB_LINK_RESERVED_8500:
diff --git a/drivers/usb/phy/phy-gpio-vbus-usb.c b/drivers/usb/phy/phy-gpio-vbus-usb.c
index f4b14bd..840dc2b 100644
--- a/drivers/usb/phy/phy-gpio-vbus-usb.c
+++ b/drivers/usb/phy/phy-gpio-vbus-usb.c
@@ -134,6 +134,7 @@ static void gpio_vbus_work(struct work_struct *work)
 
 		atomic_notifier_call_chain(&gpio_vbus->phy.notifier,
 					   status, gpio_vbus->phy.otg->gadget);
+		usb_phy_set_event(&gpio_vbus->phy, USB_EVENT_ENUMERATED);
 	} else {
 		/* optionally disable D+ pullup */
 		if (gpio_is_valid(gpio))
@@ -148,6 +149,7 @@ static void gpio_vbus_work(struct work_struct *work)
 
 		atomic_notifier_call_chain(&gpio_vbus->phy.notifier,
 					   status, gpio_vbus->phy.otg->gadget);
+		usb_phy_set_event(&gpio_vbus->phy, USB_EVENT_NONE);
 	}
 }
 
diff --git a/drivers/usb/phy/phy-mv-usb.c b/drivers/usb/phy/phy-mv-usb.c
index 7d80c54..8ed9f95 100644
--- a/drivers/usb/phy/phy-mv-usb.c
+++ b/drivers/usb/phy/phy-mv-usb.c
@@ -441,10 +441,12 @@ run:
 				mv_otg_start_periphrals(mvotg, 0);
 			mv_otg_reset(mvotg);
 			mv_otg_disable(mvotg);
+			usb_phy_set_event(&mvotg->phy, USB_EVENT_NONE);
 			break;
 		case OTG_STATE_B_PERIPHERAL:
 			mv_otg_enable(mvotg);
 			mv_otg_start_periphrals(mvotg, 1);
+			usb_phy_set_event(&mvotg->phy, USB_EVENT_ENUMERATED);
 			break;
 		case OTG_STATE_A_IDLE:
 			otg->default_a = 1;
diff --git a/drivers/usb/phy/phy-tahvo.c b/drivers/usb/phy/phy-tahvo.c
index cc61ee4..5551ef0 100644
--- a/drivers/usb/phy/phy-tahvo.c
+++ b/drivers/usb/phy/phy-tahvo.c
@@ -87,6 +87,7 @@ static void check_vbus_state(struct tahvo_usb *tu)
 			if (tu->phy.otg->gadget)
 				usb_gadget_vbus_connect(tu->phy.otg->gadget);
 			tu->phy.state = OTG_STATE_B_PERIPHERAL;
+			usb_phy_set_event(&tu->phy, USB_EVENT_ENUMERATED);
 			break;
 		case OTG_STATE_A_IDLE:
 			/*
@@ -105,6 +106,7 @@ static void check_vbus_state(struct tahvo_usb *tu)
 			if (tu->phy.otg->gadget)
 				usb_gadget_vbus_disconnect(tu->phy.otg->gadget);
 			tu->phy.state = OTG_STATE_B_IDLE;
+			usb_phy_set_event(&tu->phy, USB_EVENT_NONE);
 			break;
 		case OTG_STATE_A_HOST:
 			tu->phy.state = OTG_STATE_A_IDLE;
-- 
1.8.2.1

[PATCH 3/3] usb: phy: hold wakeupsource when USB is enumerated in peripheral mode

[Kiran Kumar Raparthy]

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From: Todd Poynor <toddpoynor@google.com>

usb: phy: hold wakeupsource when USB is enumerated in peripheral mode

Some systems require a mechanism to prevent system to enter into suspend
state when USB is connected and enumerated in peripheral mode.

This patch provides an interface to hold a wakeupsource to prevent suspend.
PHY drivers can use this interface when USB is connected and enumerated in
peripheral mode.

A timed wakeupsource is temporarily held on USB disconnect events, to allow
the rest of the system to react to the USB disconnection (dropping host
sessions, updating charger status, etc.) prior to re-allowing suspend.

Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-kernel@vger.kernel.org
Cc: linux-usb@vger.kernel.org
Cc: Android Kernel Team <kernel-team@android.com>
Cc: John Stultz <john.stultz@linaro.org>
Cc: Sumit Semwal <sumit.semwal@linaro.org>
Cc: Arve Hjønnevåg <arve@android.com>
Cc: Benoit Goby <benoit@android.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
[kiran: Added context to commit message, squished build fixes
from Benoit Goby and Arve Hjønnevåg, changed wakelocks usage
to wakeupsource, merged Todd's refactoring logic and simplified
the structures and code and addressed community feedback]
Signed-off-by: Kiran Raparthy <kiran.kumar@linaro.org>
---
 drivers/usb/phy/phy.c   | 29 +++++++++++++++++++++++++++--
 include/linux/usb/phy.h |  5 +++++
 2 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/phy/phy.c b/drivers/usb/phy/phy.c
index 2b1039e..b8a2d56 100644
--- a/drivers/usb/phy/phy.c
+++ b/drivers/usb/phy/phy.c
@@ -329,6 +329,7 @@ int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
 	int		ret = 0;
 	unsigned long	flags;
 	struct usb_phy	*phy;
+	char wsource_name[40];
 
 	if (x->type != USB_PHY_TYPE_UNDEFINED) {
 		dev_err(x->dev, "not accepting initialized PHY %s\n", x->label);
@@ -351,6 +352,10 @@ int usb_add_phy(struct usb_phy *x, enum usb_phy_type type)
 	x->type = type;
 	list_add_tail(&x->head, &phy_list);
 
+	snprintf(wsource_name, sizeof(wsource_name), "vbus-%s",
+		dev_name(x->dev));
+	wakeup_source_init(&x->wsource, wsource_name);
+
 out:
 	spin_unlock_irqrestore(&phy_lock, flags);
 	return ret;
@@ -402,6 +407,7 @@ void usb_remove_phy(struct usb_phy *x)
 
 	spin_lock_irqsave(&phy_lock, flags);
 	if (x) {
+		wakeup_source_trash(&x->wsource);
 		list_for_each_entry(phy_bind, &phy_bind_list, list)
 			if (phy_bind->phy == x)
 				phy_bind->phy = NULL;
@@ -446,13 +452,32 @@ int usb_bind_phy(const char *dev_name, u8 index,
 EXPORT_SYMBOL_GPL(usb_bind_phy);
 
 /**
- * usb_phy_set_event - set event to phy event
+ * usb_phy_set_event - set event to phy event and
+ * hold/temporarily hold wakeupsource
  * @x: the phy returned by usb_get_phy();
  *
- * This sets event to phy event
+ * This holds per-PHY wakeupsource/timed wakeupsource
  */
 void usb_phy_set_event(struct usb_phy *x, unsigned long event)
 {
+
 	x->last_event = event;
+
+	switch (event) {
+	case USB_EVENT_ENUMERATED:
+		__pm_stay_awake(&x->wsource);
+		break;
+
+	case USB_EVENT_NONE:
+	case USB_EVENT_ID:
+	case USB_EVENT_VBUS:
+	case USB_EVENT_CHARGER:
+		__pm_wakeup_event(&x->wsource,
+				  USB_PHY_DEFAULT_WAKEUP_SRC_TIMEOUT);
+		break;
+
+	default:
+		break;
+	}
 }
 EXPORT_SYMBOL_GPL(usb_phy_set_event);
diff --git a/include/linux/usb/phy.h b/include/linux/usb/phy.h
index 3c713ff..c593fc6 100644
--- a/include/linux/usb/phy.h
+++ b/include/linux/usb/phy.h
@@ -12,6 +12,8 @@
 #include <linux/notifier.h>
 #include <linux/usb.h>
 
+#define USB_PHY_DEFAULT_WAKEUP_SRC_TIMEOUT	msecs_to_jiffies(2000)
+
 enum usb_phy_interface {
 	USBPHY_INTERFACE_MODE_UNKNOWN,
 	USBPHY_INTERFACE_MODE_UTMI,
@@ -89,6 +91,9 @@ struct usb_phy {
 	/* for notification of usb_phy_events */
 	struct atomic_notifier_head	notifier;
 
+	/* wakeup source */
+	struct wakeup_source    wsource;
+
 	/* to pass extra port status to the root hub */
 	u16			port_status;
 	u16			port_change;
-- 
1.8.2.1