[RFC] [PATCH 0/6] media: em28xx - power management support em28xx

[RFC] [PATCH 0/6] media: em28xx - power management support em28xx

[Shuah Khan]

Add power management support to em28xx usb driver. This driver works in
conjunction with extensions for each of the functions on the USB device
for video/audio/dvb/remote functionality that is present on media USB
devices it supports. During suspend and resume each of these extensions
will have to do their part in suspending the components they control.

Adding suspend and resume hooks to the existing struct em28xx_ops will
enable the extensions the ability to implement suspend and resume hooks
to be called from em28xx driver. The overall approach is as follows:

-- add suspend and resume hooks to em28xx_ops
-- add suspend and resume routines to em28xx-core to invoke suspend
   and resume hooks for all registered extensions.
-- change em28xx dvb, audio, input, and video extensions to implement
   em28xx_ops: suspend and resume hooks. These hooks do what is necessary
   to suspend and resume the devices they control.

Shuah Khan (6):
  media: em28xx - add suspend/resume to em28xx_ops
  media: em28xx-audio - implement em28xx_ops: suspend/resume hooks
  media: em28xx-dvb - implement em28xx_ops: suspend/resume hooks
  media: em28xx-input - implement em28xx_ops: suspend/resume hooks
  media: em28xx-video - implement em28xx_ops: suspend/resume hooks
  media: em28xx - implement em28xx_usb_driver suspend, resume,
    reset_resume hooks

 drivers/media/usb/em28xx/em28xx-audio.c | 30 +++++++++++++++++
 drivers/media/usb/em28xx/em28xx-cards.c | 26 +++++++++++++++
 drivers/media/usb/em28xx/em28xx-core.c  | 28 ++++++++++++++++
 drivers/media/usb/em28xx/em28xx-dvb.c   | 57 +++++++++++++++++++++++++++++++++
 drivers/media/usb/em28xx/em28xx-input.c | 35 ++++++++++++++++++++
 drivers/media/usb/em28xx/em28xx-video.c | 28 ++++++++++++++++
 drivers/media/usb/em28xx/em28xx.h       |  4 +++
 7 files changed, 208 insertions(+)

-- 
1.8.3.2

[RFC] [PATCH 1/6] media: em28xx - add suspend/resume to em28xx_ops

[Shuah Khan]

em28xx usb driver will have to suspend and resume its extensions. Adding
suspend and resume to em28xx_ops gives extensions the ability to install
suspend and resume that can be invoked from em28xx_usb driver suspend()
and resume() interfaces.

Approach:
Add power management support to em28xx usb driver. This driver works in
conjunction with extensions for each of the functions on the USB device
for video/audio/dvb/remote functionality that is present on media USB
devices it supports. During suspend and resume each of these extensions
will have to do their part in suspending the components they control.

Adding suspend and resume hooks to the existing struct em28xx_ops will
enable the extensions the ability to implement suspend and resume hooks
to be called from em28xx driver. The overall approach is as follows:

-- add suspend and resume hooks to em28xx_ops
-- add suspend and resume routines to em28xx-core to invoke suspend
   and resume hooks for all registered extensions.
-- change em28xx dvb, audio, input, and video extensions to implement
   em28xx_ops: suspend and resume hooks. These hooks do what is necessary
   to suspend and resume the devices they control.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
---
 drivers/media/usb/em28xx/em28xx-core.c | 28 ++++++++++++++++++++++++++++
 drivers/media/usb/em28xx/em28xx.h      |  4 ++++
 2 files changed, 32 insertions(+)

diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c
index 898fb9b..6de41c6 100644
--- a/drivers/media/usb/em28xx/em28xx-core.c
+++ b/drivers/media/usb/em28xx/em28xx-core.c
@@ -1106,3 +1106,31 @@ void em28xx_close_extension(struct em28xx *dev)
 	list_del(&dev->devlist);
 	mutex_unlock(&em28xx_devlist_mutex);
 }
+
+int em28xx_suspend_extension(struct em28xx *dev)
+{
+	const struct em28xx_ops *ops = NULL;
+
+	em28xx_info("Suspending extensions");
+	mutex_lock(&em28xx_devlist_mutex);
+	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
+		if (ops->suspend)
+			ops->suspend(dev);
+	}
+	mutex_unlock(&em28xx_devlist_mutex);
+	return 0;
+}
+
+int em28xx_resume_extension(struct em28xx *dev)
+{
+	const struct em28xx_ops *ops = NULL;
+
+	em28xx_info("Resuming extensions");
+	mutex_lock(&em28xx_devlist_mutex);
+	list_for_each_entry(ops, &em28xx_extension_devlist, next) {
+		if (ops->resume)
+			ops->resume(dev);
+	}
+	mutex_unlock(&em28xx_devlist_mutex);
+	return 0;
+}
diff --git a/drivers/media/usb/em28xx/em28xx.h b/drivers/media/usb/em28xx/em28xx.h
index 32d8a4b..9b02f15 100644
--- a/drivers/media/usb/em28xx/em28xx.h
+++ b/drivers/media/usb/em28xx/em28xx.h
@@ -713,6 +713,8 @@ struct em28xx_ops {
 	int id;
 	int (*init)(struct em28xx *);
 	int (*fini)(struct em28xx *);
+	int (*suspend)(struct em28xx *);
+	int (*resume)(struct em28xx *);
 };
 
 /* Provided by em28xx-i2c.c */
@@ -758,6 +760,8 @@ int em28xx_register_extension(struct em28xx_ops *dev);
 void em28xx_unregister_extension(struct em28xx_ops *dev);
 void em28xx_init_extension(struct em28xx *dev);
 void em28xx_close_extension(struct em28xx *dev);
+int em28xx_suspend_extension(struct em28xx *dev);
+int em28xx_resume_extension(struct em28xx *dev);
 
 /* Provided by em28xx-cards.c */
 extern struct em28xx_board em28xx_boards[];
-- 
1.8.3.2

[RFC] [PATCH 2/6] media: em28xx-audio - implement em28xx_ops: suspend/resume hooks

[Shuah Khan]

Implement em28xx_ops: suspend/resume hooks. em28xx usb driver will
invoke em28xx_ops: suspend and resume hooks for all its extensions
from its suspend() and resume() interfaces.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
---
 drivers/media/usb/em28xx/em28xx-audio.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/media/usb/em28xx/em28xx-audio.c b/drivers/media/usb/em28xx/em28xx-audio.c
index 05e9bd1..a4d159d 100644
--- a/drivers/media/usb/em28xx/em28xx-audio.c
+++ b/drivers/media/usb/em28xx/em28xx-audio.c
@@ -989,11 +989,41 @@ static int em28xx_audio_fini(struct em28xx *dev)
 	return 0;
 }
 
+static int em28xx_audio_suspend(struct em28xx *dev)
+{
+	if (dev == NULL)
+		return 0;
+
+	if (!dev->has_alsa_audio)
+		return 0;
+
+	em28xx_info("Suspending audio extension");
+	em28xx_deinit_isoc_audio(dev);
+	atomic_set(&dev->stream_started, 0);
+	return 0;
+}
+
+static int em28xx_audio_resume(struct em28xx *dev)
+{
+	if (dev == NULL)
+		return 0;
+
+	if (!dev->has_alsa_audio)
+		return 0;
+
+	em28xx_info("Resuming audio extension");
+	/* Nothing to do other than schedule_work() ?? */
+	schedule_work(&dev->wq_trigger);
+	return 0;
+}
+
 static struct em28xx_ops audio_ops = {
 	.id   = EM28XX_AUDIO,
 	.name = "Em28xx Audio Extension",
 	.init = em28xx_audio_init,
 	.fini = em28xx_audio_fini,
+	.suspend = em28xx_audio_suspend,
+	.resume = em28xx_audio_resume,
 };
 
 static int __init em28xx_alsa_register(void)
-- 
1.8.3.2

[RFC] [PATCH 3/6] media: em28xx-dvb - implement em28xx_ops: suspend/resume hooks

[Shuah Khan]

Implement em28xx_ops: suspend/resume hooks. em28xx usb driver will
invoke em28xx_ops: suspend and resume hooks for all its extensions
from its suspend() and resume() interfaces.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
---
 drivers/media/usb/em28xx/em28xx-dvb.c | 57 +++++++++++++++++++++++++++++++++++
 1 file changed, 57 insertions(+)

diff --git a/drivers/media/usb/em28xx/em28xx-dvb.c b/drivers/media/usb/em28xx/em28xx-dvb.c
index a0a669e..736b674 100644
--- a/drivers/media/usb/em28xx/em28xx-dvb.c
+++ b/drivers/media/usb/em28xx/em28xx-dvb.c
@@ -1492,11 +1492,68 @@ static int em28xx_dvb_fini(struct em28xx *dev)
 	return 0;
 }
 
+static int em28xx_dvb_suspend(struct em28xx *dev)
+{
+	int ret = 0;
+
+	if (dev->is_audio_only)
+		return 0;
+
+	if (!dev->board.has_dvb)
+		return 0;
+
+	em28xx_info("Suspending DVB extension");
+	if (dev->dvb) {
+		struct em28xx_dvb *dvb = dev->dvb;
+
+		if (dvb->fe[0]) {
+			ret = dvb_frontend_suspend(dvb->fe[0]);
+			em28xx_info("fe0 suspend %d", ret);
+		}
+		if (dvb->fe[1]) {
+			dvb_frontend_suspend(dvb->fe[1]);
+			em28xx_info("fe1 suspend %d", ret);
+		}
+	}
+
+	return 0;
+}
+
+static int em28xx_dvb_resume(struct em28xx *dev)
+{
+	int ret = 0;
+
+	if (dev->is_audio_only)
+		return 0;
+
+	if (!dev->board.has_dvb)
+		return 0;
+
+	em28xx_info("Resuming DVB extension");
+	if (dev->dvb) {
+		struct em28xx_dvb *dvb = dev->dvb;
+
+		if (dvb->fe[0]) {
+			ret = dvb_frontend_resume(dvb->fe[0]);
+			em28xx_info("fe0 resume %d", ret);
+		}
+
+		if (dvb->fe[1]) {
+			ret = dvb_frontend_resume(dvb->fe[1]);
+			em28xx_info("fe1 resume %d", ret);
+		}
+	}
+
+	return 0;
+}
+
 static struct em28xx_ops dvb_ops = {
 	.id   = EM28XX_DVB,
 	.name = "Em28xx dvb Extension",
 	.init = em28xx_dvb_init,
 	.fini = em28xx_dvb_fini,
+	.suspend = em28xx_dvb_suspend,
+	.resume = em28xx_dvb_resume,
 };
 
 static int __init em28xx_dvb_register(void)
-- 
1.8.3.2

[RFC] [PATCH 4/6] media: em28xx-input - implement em28xx_ops: suspend/resume hooks

[Shuah Khan]

Implement em28xx_ops: suspend/resume hooks. em28xx usb driver will
invoke em28xx_ops: suspend and resume hooks for all its extensions
from its suspend() and resume() interfaces.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
---
 drivers/media/usb/em28xx/em28xx-input.c | 35 +++++++++++++++++++++++++++++++++
 1 file changed, 35 insertions(+)

diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c
index 18f65d8..1227309 100644
--- a/drivers/media/usb/em28xx/em28xx-input.c
+++ b/drivers/media/usb/em28xx/em28xx-input.c
@@ -827,11 +827,46 @@ static int em28xx_ir_fini(struct em28xx *dev)
 	return 0;
 }
 
+static int em28xx_ir_suspend(struct em28xx *dev)
+{
+	struct em28xx_IR *ir = dev->ir;
+
+	if (dev->is_audio_only)
+		return 0;
+
+	em28xx_info("Suspending input extension");
+	cancel_delayed_work_sync(&ir->work);
+	cancel_delayed_work_sync(&dev->buttons_query_work);
+	/* is canceling delayed work sufficient or does the rc event
+	   kthread needs stopping? kthread is stopped in
+	   ir_raw_event_unregister() */
+	return 0;
+}
+
+static int em28xx_ir_resume(struct em28xx *dev)
+{
+	struct em28xx_IR *ir = dev->ir;
+
+	if (dev->is_audio_only)
+		return 0;
+
+	em28xx_info("Resuming input extension");
+	/* if suspend calls ir_raw_event_unregister(), the should call
+	   ir_raw_event_register() */
+	schedule_delayed_work_sync(&ir->work);
+	if (dev->num_button_polling_addresses)
+		schedule_delayed_work(&dev->buttons_query_work,
+			       msecs_to_jiffies(dev->button_polling_interval));
+	return 0;
+}
+
 static struct em28xx_ops rc_ops = {
 	.id   = EM28XX_RC,
 	.name = "Em28xx Input Extension",
 	.init = em28xx_ir_init,
 	.fini = em28xx_ir_fini,
+	.suspend = em28xx_ir_suspend,
+	.resume = em28xx_ir_resume,
 };
 
 static int __init em28xx_rc_register(void)
-- 
1.8.3.2

Re: [RFC] [PATCH 4/6] media: em28xx-input - implement em28xx_ops: suspend/resume hooks

[Mauro Carvalho Chehab]

Em Fri, 21 Feb 2014 17:50:16 -0700
Shuah Khan <shuah.kh@samsung.com> escreveu:

> Implement em28xx_ops: suspend/resume hooks. em28xx usb driver will
> invoke em28xx_ops: suspend and resume hooks for all its extensions
> from its suspend() and resume() interfaces.
> 
> Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
> ---
>  drivers/media/usb/em28xx/em28xx-input.c | 35 +++++++++++++++++++++++++++++++++
>  1 file changed, 35 insertions(+)
> 
> diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c
> index 18f65d8..1227309 100644
> --- a/drivers/media/usb/em28xx/em28xx-input.c
> +++ b/drivers/media/usb/em28xx/em28xx-input.c
> @@ -827,11 +827,46 @@ static int em28xx_ir_fini(struct em28xx *dev)
>  	return 0;
>  }
>  
> +static int em28xx_ir_suspend(struct em28xx *dev)
> +{
> +	struct em28xx_IR *ir = dev->ir;
> +
> +	if (dev->is_audio_only)
> +		return 0;
> +
> +	em28xx_info("Suspending input extension");
> +	cancel_delayed_work_sync(&ir->work);
> +	cancel_delayed_work_sync(&dev->buttons_query_work);
> +	/* is canceling delayed work sufficient or does the rc event
> +	   kthread needs stopping? kthread is stopped in
> +	   ir_raw_event_unregister() */
> +	return 0;
> +}
> +
> +static int em28xx_ir_resume(struct em28xx *dev)
> +{
> +	struct em28xx_IR *ir = dev->ir;
> +
> +	if (dev->is_audio_only)
> +		return 0;
> +
> +	em28xx_info("Resuming input extension");
> +	/* if suspend calls ir_raw_event_unregister(), the should call
> +	   ir_raw_event_register() */
> +	schedule_delayed_work_sync(&ir->work);

This causes a compilation breakage:

drivers/media/usb/em28xx/em28xx-input.c: In function ‘em28xx_ir_resume’:
drivers/media/usb/em28xx/em28xx-input.c:856:2: error: implicit declaration of function ‘schedule_delayed_work_sync’ [-Werror=implicit-function-declaration]
  schedule_delayed_work_sync(&ir->work);


> +	if (dev->num_button_polling_addresses)
> +		schedule_delayed_work(&dev->buttons_query_work,
> +			       msecs_to_jiffies(dev->button_polling_interval));
> +	return 0;
> +}
> +
>  static struct em28xx_ops rc_ops = {
>  	.id   = EM28XX_RC,
>  	.name = "Em28xx Input Extension",
>  	.init = em28xx_ir_init,
>  	.fini = em28xx_ir_fini,
> +	.suspend = em28xx_ir_suspend,
> +	.resume = em28xx_ir_resume,
>  };
>  
>  static int __init em28xx_rc_register(void)


-- 

Cheers,
Mauro

Re: [RFC] [PATCH 4/6] media: em28xx-input - implement em28xx_ops: suspend/resume hooks

[Mauro Carvalho Chehab]

Em Sat, 01 Mar 2014 10:48:35 -0300
Mauro Carvalho Chehab <m.chehab@samsung.com> escreveu:

> Em Fri, 21 Feb 2014 17:50:16 -0700
> Shuah Khan <shuah.kh@samsung.com> escreveu:
> 
> > Implement em28xx_ops: suspend/resume hooks. em28xx usb driver will
> > invoke em28xx_ops: suspend and resume hooks for all its extensions
> > from its suspend() and resume() interfaces.
> > 
> > Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
> > ---
> >  drivers/media/usb/em28xx/em28xx-input.c | 35 +++++++++++++++++++++++++++++++++
> >  1 file changed, 35 insertions(+)
> > 
> > diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c
> > index 18f65d8..1227309 100644
> > --- a/drivers/media/usb/em28xx/em28xx-input.c
> > +++ b/drivers/media/usb/em28xx/em28xx-input.c
> > @@ -827,11 +827,46 @@ static int em28xx_ir_fini(struct em28xx *dev)
> >  	return 0;
> >  }
> >  
> > +static int em28xx_ir_suspend(struct em28xx *dev)
> > +{
> > +	struct em28xx_IR *ir = dev->ir;
> > +
> > +	if (dev->is_audio_only)
> > +		return 0;
> > +
> > +	em28xx_info("Suspending input extension");
> > +	cancel_delayed_work_sync(&ir->work);
> > +	cancel_delayed_work_sync(&dev->buttons_query_work);
> > +	/* is canceling delayed work sufficient or does the rc event
> > +	   kthread needs stopping? kthread is stopped in
> > +	   ir_raw_event_unregister() */
> > +	return 0;
> > +}
> > +
> > +static int em28xx_ir_resume(struct em28xx *dev)
> > +{
> > +	struct em28xx_IR *ir = dev->ir;
> > +
> > +	if (dev->is_audio_only)
> > +		return 0;
> > +
> > +	em28xx_info("Resuming input extension");
> > +	/* if suspend calls ir_raw_event_unregister(), the should call
> > +	   ir_raw_event_register() */
> > +	schedule_delayed_work_sync(&ir->work);
> 
> This causes a compilation breakage:
> 
> drivers/media/usb/em28xx/em28xx-input.c: In function ‘em28xx_ir_resume’:
> drivers/media/usb/em28xx/em28xx-input.c:856:2: error: implicit declaration of function ‘schedule_delayed_work_sync’ [-Werror=implicit-function-declaration]
>   schedule_delayed_work_sync(&ir->work);
> 

Ok, I reworked it fixing the above compilation bug, and added a test to
be sure that IR is enabled before using ir->work.

Patch enclosed.

This series look OK on my eyes with this change, and it worked fine
here with PCTV 80e, so I'll be merging it. In any case, this won't
cause any regressions, as suspending before those patches on those 
devices make the machine to hang.

Regards,
Mauro

From: Shuah Khan <shuah.kh@samsung.com>
Date: Fri, 21 Feb 2014 21:50:16 -0300
Subject: [PATCH] [media] em28xx-input: implement em28xx_ops: suspend/resume
 hooks

Implement em28xx_ops: suspend/resume hooks. em28xx usb driver will
invoke em28xx_ops: suspend and resume hooks for all its extensions
from its suspend() and resume() interfaces.

[m.chehab@samsung.com: Fix a breakage caused by calling a non-existing
 function call: schedule_delayed_work_sync(), and test if IR was defined
 at suspend/resume]
Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>

diff --git a/drivers/media/usb/em28xx/em28xx-input.c b/drivers/media/usb/em28xx/em28xx-input.c
index 048e5b680499..47a2c1dcccbf 100644
--- a/drivers/media/usb/em28xx/em28xx-input.c
+++ b/drivers/media/usb/em28xx/em28xx-input.c
@@ -827,11 +827,48 @@ static int em28xx_ir_fini(struct em28xx *dev)
 	return 0;
 }
 
+static int em28xx_ir_suspend(struct em28xx *dev)
+{
+	struct em28xx_IR *ir = dev->ir;
+
+	if (dev->is_audio_only)
+		return 0;
+
+	em28xx_info("Suspending input extension");
+	if (ir)
+		cancel_delayed_work_sync(&ir->work);
+	cancel_delayed_work_sync(&dev->buttons_query_work);
+	/* is canceling delayed work sufficient or does the rc event
+	   kthread needs stopping? kthread is stopped in
+	   ir_raw_event_unregister() */
+	return 0;
+}
+
+static int em28xx_ir_resume(struct em28xx *dev)
+{
+	struct em28xx_IR *ir = dev->ir;
+
+	if (dev->is_audio_only)
+		return 0;
+
+	em28xx_info("Resuming input extension");
+	/* if suspend calls ir_raw_event_unregister(), the should call
+	   ir_raw_event_register() */
+	if (ir)
+		schedule_delayed_work(&ir->work, msecs_to_jiffies(ir->polling));
+	if (dev->num_button_polling_addresses)
+		schedule_delayed_work(&dev->buttons_query_work,
+			       msecs_to_jiffies(dev->button_polling_interval));
+	return 0;
+}
+
 static struct em28xx_ops rc_ops = {
 	.id   = EM28XX_RC,
 	.name = "Em28xx Input Extension",
 	.init = em28xx_ir_init,
 	.fini = em28xx_ir_fini,
+	.suspend = em28xx_ir_suspend,
+	.resume = em28xx_ir_resume,
 };
 
 static int __init em28xx_rc_register(void)



-- 

Cheers,
Mauro

[RFC] [PATCH 5/6] media: em28xx-video - implement em28xx_ops: suspend/resume hooks

[Shuah Khan]

Implement em28xx_ops: suspend/resume hooks. em28xx usb driver will
invoke em28xx_ops: suspend and resume hooks for all its extensions
from its suspend() and resume() interfaces.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
---
 drivers/media/usb/em28xx/em28xx-video.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/drivers/media/usb/em28xx/em28xx-video.c b/drivers/media/usb/em28xx/em28xx-video.c
index c3c9289..1df6750 100644
--- a/drivers/media/usb/em28xx/em28xx-video.c
+++ b/drivers/media/usb/em28xx/em28xx-video.c
@@ -1933,6 +1933,32 @@ static int em28xx_v4l2_fini(struct em28xx *dev)
 	return 0;
 }
 
+static int em28xx_v4l2_suspend(struct em28xx *dev)
+{
+	if (dev->is_audio_only)
+		return 0;
+
+	if (!dev->has_video)
+		return 0;
+
+	em28xx_info("Suspending video extension");
+	em28xx_stop_urbs(dev);
+	return 0;
+}
+
+static int em28xx_v4l2_resume(struct em28xx *dev)
+{
+	if (dev->is_audio_only)
+		return 0;
+
+	if (!dev->has_video)
+		return 0;
+
+	em28xx_info("Resuming video extension");
+	/* what do we do here */
+	return 0;
+}
+
 /*
  * em28xx_v4l2_close()
  * stops streaming and deallocates all resources allocated by the v4l2
@@ -2504,6 +2530,8 @@ static struct em28xx_ops v4l2_ops = {
 	.name = "Em28xx v4l2 Extension",
 	.init = em28xx_v4l2_init,
 	.fini = em28xx_v4l2_fini,
+	.suspend = em28xx_v4l2_suspend,
+	.resume = em28xx_v4l2_resume,
 };
 
 static int __init em28xx_video_register(void)
-- 
1.8.3.2

[RFC] [PATCH 6/6] media: em28xx - implement em28xx_usb_driver suspend, resume, reset_resume hooks

[Shuah Khan]

Implement em28xx_usb_driver suspend, resume, and reset_resume hooks.
These hooks will invoke em28xx core em28xx_suspend_extension() and
em28xx_resume_extension() to suspend and resume registered extensions.

Approach:
Add power management support to em28xx usb driver. This driver works in
conjunction with extensions for each of the functions on the USB device
for video/audio/dvb/remote functionality that is present on media USB
devices it supports. During suspend and resume each of these extensions
will have to do their part in suspending the components they control.

Adding suspend and resume hooks to the existing struct em28xx_ops will
enable the extensions the ability to implement suspend and resume hooks
to be called from em28xx driver. The overall approach is as follows:

-- add suspend and resume hooks to em28xx_ops
-- add suspend and resume routines to em28xx-core to invoke suspend
   and resume hooks for all registered extensions.
-- change em28xx dvb, audio, input, and video extensions to implement
   em28xx_ops: suspend and resume hooks. These hooks do what is necessary
   to suspend and resume the devices they control.

Signed-off-by: Shuah Khan <shuah.kh@samsung.com>
---
 drivers/media/usb/em28xx/em28xx-cards.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/media/usb/em28xx/em28xx-cards.c b/drivers/media/usb/em28xx/em28xx-cards.c
index 2401240..2e68f51 100644
--- a/drivers/media/usb/em28xx/em28xx-cards.c
+++ b/drivers/media/usb/em28xx/em28xx-cards.c
@@ -3395,10 +3395,36 @@ static void em28xx_usb_disconnect(struct usb_interface *interface)
 	}
 }
 
+static int em28xx_usb_suspend(struct usb_interface *interface,
+				pm_message_t message)
+{
+	struct em28xx *dev;
+
+	dev = usb_get_intfdata(interface);
+	if (!dev)
+		return 0;
+	em28xx_suspend_extension(dev);
+	return 0;
+}
+
+static int em28xx_usb_resume(struct usb_interface *interface)
+{
+	struct em28xx *dev;
+
+	dev = usb_get_intfdata(interface);
+	if (!dev)
+		return 0;
+	em28xx_resume_extension(dev);
+	return 0;
+}
+
 static struct usb_driver em28xx_usb_driver = {
 	.name = "em28xx",
 	.probe = em28xx_usb_probe,
 	.disconnect = em28xx_usb_disconnect,
+	.suspend = em28xx_usb_suspend,
+	.resume = em28xx_usb_resume,
+	.reset_resume = em28xx_usb_resume,
 	.id_table = em28xx_id_table,
 };
 
-- 
1.8.3.2