Hi Laurent,
Thanks for the comments.
On Sat, May 23, 2015 at 09:47:28PM +0300, Laurent Pinchart wrote:
> Hi Sakari,
>
> Thank you for the patch.
>
> On Wednesday 20 May 2015 02:04:01 Sakari Ailus wrote:
> > V4L2 async sub-devices are currently matched (OF case) based on the struct
> > device_node pointer in struct device. LED devices may have more than one
> > LED, and in that case the OF node to match is not directly the device's
> > node, but a LED's node.
> >
> > Signed-off-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
> > Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxx>
> > ---
> > drivers/media/v4l2-core/v4l2-async.c | 34 +++++++++++++++++++-----------
> > drivers/media/v4l2-core/v4l2-device.c | 3 +++
> > include/media/v4l2-subdev.h | 2 ++
> > 3 files changed, 27 insertions(+), 12 deletions(-)
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-async.c
> > b/drivers/media/v4l2-core/v4l2-async.c index 85a6a34..bcdd140 100644
> > --- a/drivers/media/v4l2-core/v4l2-async.c
> > +++ b/drivers/media/v4l2-core/v4l2-async.c
> > @@ -22,10 +22,10 @@
> > #include <media/v4l2-device.h>
> > #include <media/v4l2-subdev.h>
> >
> > -static bool match_i2c(struct device *dev, struct v4l2_async_subdev *asd)
> > +static bool match_i2c(struct v4l2_subdev *sd, struct v4l2_async_subdev
> > *asd) {
> > #if IS_ENABLED(CONFIG_I2C)
> > - struct i2c_client *client = i2c_verify_client(dev);
> > + struct i2c_client *client = i2c_verify_client(sd->dev);
> > return client &&
> > asd->match.i2c.adapter_id == client->adapter->nr &&
> > asd->match.i2c.address == client->addr;
> > @@ -34,14 +34,27 @@ static bool match_i2c(struct device *dev, struct
> > v4l2_async_subdev *asd) #endif
> > }
> >
> > -static bool match_devname(struct device *dev, struct v4l2_async_subdev
> > *asd) +static bool match_devname(struct v4l2_subdev *sd,
> > + struct v4l2_async_subdev *asd)
> > {
> > - return !strcmp(asd->match.device_name.name, dev_name(dev));
> > + return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
> > }
> >
> > -static bool match_of(struct device *dev, struct v4l2_async_subdev *asd)
> > +static bool match_of(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> > {
> > - return dev->of_node == asd->match.of.node;
> > + struct device_node *of_node =
> > + sd->of_node ? sd->of_node : sd->dev->of_node;
> > +
> > + return of_node == asd->match.of.node;
> > +}
> > +
> > +static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev
> > *asd) +{
> > + if (!asd->match.custom.match)
> > + /* Match always */
> > + return true;
> > +
> > + return asd->match.custom.match(sd->dev, asd);
> > }
> >
> > static LIST_HEAD(subdev_list);
> > @@ -51,17 +64,14 @@ static DEFINE_MUTEX(list_lock);
> > static struct v4l2_async_subdev *v4l2_async_belongs(struct
> > v4l2_async_notifier *notifier, struct v4l2_subdev *sd)
> > {
> > + bool (*match)(struct v4l2_subdev *, struct v4l2_async_subdev *);
> > struct v4l2_async_subdev *asd;
> > - bool (*match)(struct device *, struct v4l2_async_subdev *);
> >
> > list_for_each_entry(asd, ¬ifier->waiting, list) {
> > /* bus_type has been verified valid before */
> > switch (asd->match_type) {
> > case V4L2_ASYNC_MATCH_CUSTOM:
> > - match = asd->match.custom.match;
> > - if (!match)
> > - /* Match always */
> > - return asd;
> > + match = match_custom;
> > break;
> > case V4L2_ASYNC_MATCH_DEVNAME:
> > match = match_devname;
> > @@ -79,7 +89,7 @@ static struct v4l2_async_subdev *v4l2_async_belongs(struct
> > v4l2_async_notifier * }
> >
> > /* match cannot be NULL here */
> > - if (match(sd->dev, asd))
> > + if (match(sd, asd))
> > return asd;
> > }
> >
> > diff --git a/drivers/media/v4l2-core/v4l2-device.c
> > b/drivers/media/v4l2-core/v4l2-device.c index 5b0a30b..a741c6c 100644
> > --- a/drivers/media/v4l2-core/v4l2-device.c
> > +++ b/drivers/media/v4l2-core/v4l2-device.c
> > @@ -157,6 +157,9 @@ int v4l2_device_register_subdev(struct v4l2_device
> > *v4l2_dev, /* Warn if we apparently re-register a subdev */
> > WARN_ON(sd->v4l2_dev != NULL);
> >
> > + if (!sd->of_node && sd->dev)
> > + sd->of_node = sd->dev->of_node;
> > +
> > /*
> > * The reason to acquire the module here is to avoid unloading
> > * a module of sub-device which is registered to a media
> > diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h
> > index 8f5da73..5c51987 100644
> > --- a/include/media/v4l2-subdev.h
> > +++ b/include/media/v4l2-subdev.h
> > @@ -603,6 +603,8 @@ struct v4l2_subdev {
> > struct video_device *devnode;
> > /* pointer to the physical device, if any */
> > struct device *dev;
> > + /* A device_node of the sub-device, iff not dev->of_node. */
>
> "iff" ?
>
> I think we need to define usage of this field more precisely. If the subdev
> driver doesn't initialize it it will be set in v4l2_device_register_subdev(),
> meaning that there's part of the lifetime of the subdev during which the field
> will be NULL even though the subdev's device has a DT node. Could that be a
> problem, aren't there cases when we would need to access sd->of_node before
> v4l2_device_register_subdev(), in particular when using V4l2-async ?
Thinking about this again, I'll move the check for sd->of_node and the
assignment to v4l2_async_register_subdev() instead. This way the field will
always be available. The extra check in match_of() isn't needed in that
case.
The comment would be:
/* A device_node of the subdev, usually the same as dev->of_node. */
The alternative would be to change all the drivers using V4L2 async (and OF)
but there are quite a few of them.
What do you think?
>
> > + struct device_node *of_node;
> > /* Links this subdev to a global subdev_list or @notifier->done list. */
> > struct list_head async_list;
> > /* Pointer to respective struct v4l2_async_subdev. */
--
Regards,
Sakari Ailus
e-mail: sakari.ailus@xxxxxx XMPP: sailus@xxxxxxxxxxxxxx
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