diff mbox

[v3,2/2] v4l: async: Match parent devices

Message ID 6154c8f092e1cb4f5286c1f11f4a846c821b53d6.1495473356.git-series.kieran.bingham+renesas@ideasonboard.com (mailing list archive)
State Superseded
Delegated to: Geert Uytterhoeven
Headers show

Commit Message

Kieran Bingham May 22, 2017, 5:36 p.m. UTC
From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

Devices supporting multiple endpoints on a single device node must set
their subdevice fwnode to the endpoint to allow distinct comparisons.

Adapt the match_fwnode call to compare against the provided fwnodes
first, but also to search for a comparison against the parent fwnode.

This allows notifiers to pass the endpoint for comparison and still
support existing subdevices which store their default parent device
node.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>

---
v2:
 - Added documentation comments
 - simplified the OF match by adding match_fwnode_of()

v3:
 - Fix comments
 - Fix sd_parent, and asd_parent usage

 drivers/media/v4l2-core/v4l2-async.c | 36 ++++++++++++++++++++++++-----
 1 file changed, 31 insertions(+), 5 deletions(-)

Comments

Sakari Ailus May 23, 2017, 1:02 p.m. UTC | #1
Hi Kieran,

On Mon, May 22, 2017 at 06:36:38PM +0100, Kieran Bingham wrote:
> From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> 
> Devices supporting multiple endpoints on a single device node must set
> their subdevice fwnode to the endpoint to allow distinct comparisons.
> 
> Adapt the match_fwnode call to compare against the provided fwnodes
> first, but also to search for a comparison against the parent fwnode.
> 
> This allows notifiers to pass the endpoint for comparison and still
> support existing subdevices which store their default parent device
> node.
> 
> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> 
> ---
> v2:
>  - Added documentation comments
>  - simplified the OF match by adding match_fwnode_of()
> 
> v3:
>  - Fix comments
>  - Fix sd_parent, and asd_parent usage
> 
>  drivers/media/v4l2-core/v4l2-async.c | 36 ++++++++++++++++++++++++-----
>  1 file changed, 31 insertions(+), 5 deletions(-)
> 
> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> index cbd919d4edd2..12c0707851fd 100644
> --- a/drivers/media/v4l2-core/v4l2-async.c
> +++ b/drivers/media/v4l2-core/v4l2-async.c
> @@ -41,14 +41,40 @@ static bool match_devname(struct v4l2_subdev *sd,
>  	return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
>  }
>  
> +/*
> + * Check whether the two device_node pointers refer to the same OF node. We
> + * can't compare pointers directly as they can differ if overlays have been
> + * applied.
> + */
> +static bool match_fwnode_of(struct fwnode_handle *a, struct fwnode_handle *b)
> +{
> +	return !of_node_cmp(of_node_full_name(to_of_node(a)),
> +			    of_node_full_name(to_of_node(b)));
> +}
> +
> +/*
> + * As a measure to support drivers which have not been converted to use
> + * endpoint matching, we also find the parent devices for cross-matching.
> + *
> + * When all devices use endpoint matching, this code can be simplified, and the
> + * parent comparisons can be removed.
> + */
>  static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
>  {
> -	if (!is_of_node(sd->fwnode) || !is_of_node(asd->match.fwnode.fwnode))
> -		return sd->fwnode == asd->match.fwnode.fwnode;
> +	struct fwnode_handle *asd_fwnode = asd->match.fwnode.fwnode;
> +	struct fwnode_handle *sd_parent, *asd_parent;
> +
> +	sd_parent = fwnode_graph_get_port_parent(sd->fwnode);
> +	asd_parent = fwnode_graph_get_port_parent(asd_fwnode);
> +
> +	if (!is_of_node(sd->fwnode) || !is_of_node(asd_fwnode))
> +		return sd->fwnode == asd_fwnode ||
> +		       sd_parent == asd_fwnode ||
> +		       sd->fwnode == asd_parent;
>  
> -	return !of_node_cmp(of_node_full_name(to_of_node(sd->fwnode)),
> -			    of_node_full_name(
> -				    to_of_node(asd->match.fwnode.fwnode)));
> +	return match_fwnode_of(sd->fwnode, asd_fwnode) ||
> +	       match_fwnode_of(sd_parent, asd_fwnode) ||
> +	       match_fwnode_of(sd->fwnode, asd_parent);
>  }
>  
>  static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)

Would this become easier to read if you handled all matching in what is
called match_fwnode_of() above, also for non-OF fwnodes? Essentially you'd
have what used to be match_fwnode() there, and new match_fwnode() would call
that function with all the three combinations.

I'd call the other function __match_fwnode() for instance.
Kieran Bingham May 23, 2017, 5:40 p.m. UTC | #2
On 23/05/17 14:02, Sakari Ailus wrote:
> Hi Kieran,
> 
> On Mon, May 22, 2017 at 06:36:38PM +0100, Kieran Bingham wrote:
>> From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>
>> Devices supporting multiple endpoints on a single device node must set
>> their subdevice fwnode to the endpoint to allow distinct comparisons.
>>
>> Adapt the match_fwnode call to compare against the provided fwnodes
>> first, but also to search for a comparison against the parent fwnode.
>>
>> This allows notifiers to pass the endpoint for comparison and still
>> support existing subdevices which store their default parent device
>> node.
>>
>> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
>>
>> ---
>> v2:
>>  - Added documentation comments
>>  - simplified the OF match by adding match_fwnode_of()
>>
>> v3:
>>  - Fix comments
>>  - Fix sd_parent, and asd_parent usage
>>
>>  drivers/media/v4l2-core/v4l2-async.c | 36 ++++++++++++++++++++++++-----
>>  1 file changed, 31 insertions(+), 5 deletions(-)
>>
>> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
>> index cbd919d4edd2..12c0707851fd 100644
>> --- a/drivers/media/v4l2-core/v4l2-async.c
>> +++ b/drivers/media/v4l2-core/v4l2-async.c
>> @@ -41,14 +41,40 @@ static bool match_devname(struct v4l2_subdev *sd,
>>  	return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
>>  }
>>  
>> +/*
>> + * Check whether the two device_node pointers refer to the same OF node. We
>> + * can't compare pointers directly as they can differ if overlays have been
>> + * applied.
>> + */
>> +static bool match_fwnode_of(struct fwnode_handle *a, struct fwnode_handle *b)
>> +{
>> +	return !of_node_cmp(of_node_full_name(to_of_node(a)),
>> +			    of_node_full_name(to_of_node(b)));
>> +}
>> +
>> +/*
>> + * As a measure to support drivers which have not been converted to use
>> + * endpoint matching, we also find the parent devices for cross-matching.
>> + *
>> + * When all devices use endpoint matching, this code can be simplified, and the
>> + * parent comparisons can be removed.
>> + */
>>  static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
>>  {
>> -	if (!is_of_node(sd->fwnode) || !is_of_node(asd->match.fwnode.fwnode))
>> -		return sd->fwnode == asd->match.fwnode.fwnode;
>> +	struct fwnode_handle *asd_fwnode = asd->match.fwnode.fwnode;
>> +	struct fwnode_handle *sd_parent, *asd_parent;
>> +
>> +	sd_parent = fwnode_graph_get_port_parent(sd->fwnode);
>> +	asd_parent = fwnode_graph_get_port_parent(asd_fwnode);
>> +
>> +	if (!is_of_node(sd->fwnode) || !is_of_node(asd_fwnode))
>> +		return sd->fwnode == asd_fwnode ||
>> +		       sd_parent == asd_fwnode ||
>> +		       sd->fwnode == asd_parent;
>>  
>> -	return !of_node_cmp(of_node_full_name(to_of_node(sd->fwnode)),
>> -			    of_node_full_name(
>> -				    to_of_node(asd->match.fwnode.fwnode)));
>> +	return match_fwnode_of(sd->fwnode, asd_fwnode) ||
>> +	       match_fwnode_of(sd_parent, asd_fwnode) ||
>> +	       match_fwnode_of(sd->fwnode, asd_parent);
>>  }
>>  
>>  static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> 
> Would this become easier to read if you handled all matching in what is
> called match_fwnode_of() above, also for non-OF fwnodes? Essentially you'd
> have what used to be match_fwnode() there, and new match_fwnode() would call
> that function with all the three combinations.
> 


> I'd call the other function __match_fwnode() for instance.
> 


Yes - Took me a moment to understand what you meant here - but yes it's leaner +
cleaner:


/*
 * As a measure to support drivers which have not been converted to use
 * endpoint matching, we also find the parent devices for cross-matching.
 *
 * When all devices use endpoint matching, this code can be simplified, and the
 * parent comparisons can be removed.
 */

static bool __match_fwnode(struct fwnode_handle *a, struct fwnode_handle *b)
{
	if (is_of_node(a) || is_of_node(b))
		return !of_node_cmp(of_node_full_name(to_of_node(a)),
				    of_node_full_name(to_of_node(b)));
	else
		return a == b;
}

static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
{
	struct fwnode_handle *asd_fwnode = asd->match.fwnode.fwnode;
	struct fwnode_handle *sd_parent, *asd_parent;

	sd_parent = fwnode_graph_get_port_parent(sd->fwnode);
	asd_parent = fwnode_graph_get_port_parent(asd_fwnode);

	return __match_fwnode(sd->fwnode, asd_fwnode) ||
	       __match_fwnode(sd_parent, asd_fwnode) ||
	       __match_fwnode(sd->fwnode, asd_parent);
}
Sakari Ailus May 23, 2017, 9:40 p.m. UTC | #3
Hi Kieran,

On Tue, May 23, 2017 at 06:40:08PM +0100, Kieran Bingham wrote:
> On 23/05/17 14:02, Sakari Ailus wrote:
> > Hi Kieran,
> > 
> > On Mon, May 22, 2017 at 06:36:38PM +0100, Kieran Bingham wrote:
> >> From: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >>
> >> Devices supporting multiple endpoints on a single device node must set
> >> their subdevice fwnode to the endpoint to allow distinct comparisons.
> >>
> >> Adapt the match_fwnode call to compare against the provided fwnodes
> >> first, but also to search for a comparison against the parent fwnode.
> >>
> >> This allows notifiers to pass the endpoint for comparison and still
> >> support existing subdevices which store their default parent device
> >> node.
> >>
> >> Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
> >>
> >> ---
> >> v2:
> >>  - Added documentation comments
> >>  - simplified the OF match by adding match_fwnode_of()
> >>
> >> v3:
> >>  - Fix comments
> >>  - Fix sd_parent, and asd_parent usage
> >>
> >>  drivers/media/v4l2-core/v4l2-async.c | 36 ++++++++++++++++++++++++-----
> >>  1 file changed, 31 insertions(+), 5 deletions(-)
> >>
> >> diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
> >> index cbd919d4edd2..12c0707851fd 100644
> >> --- a/drivers/media/v4l2-core/v4l2-async.c
> >> +++ b/drivers/media/v4l2-core/v4l2-async.c
> >> @@ -41,14 +41,40 @@ static bool match_devname(struct v4l2_subdev *sd,
> >>  	return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
> >>  }
> >>  
> >> +/*
> >> + * Check whether the two device_node pointers refer to the same OF node. We
> >> + * can't compare pointers directly as they can differ if overlays have been
> >> + * applied.
> >> + */
> >> +static bool match_fwnode_of(struct fwnode_handle *a, struct fwnode_handle *b)
> >> +{
> >> +	return !of_node_cmp(of_node_full_name(to_of_node(a)),
> >> +			    of_node_full_name(to_of_node(b)));
> >> +}
> >> +
> >> +/*
> >> + * As a measure to support drivers which have not been converted to use
> >> + * endpoint matching, we also find the parent devices for cross-matching.
> >> + *
> >> + * When all devices use endpoint matching, this code can be simplified, and the
> >> + * parent comparisons can be removed.
> >> + */
> >>  static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> >>  {
> >> -	if (!is_of_node(sd->fwnode) || !is_of_node(asd->match.fwnode.fwnode))
> >> -		return sd->fwnode == asd->match.fwnode.fwnode;
> >> +	struct fwnode_handle *asd_fwnode = asd->match.fwnode.fwnode;
> >> +	struct fwnode_handle *sd_parent, *asd_parent;
> >> +
> >> +	sd_parent = fwnode_graph_get_port_parent(sd->fwnode);
> >> +	asd_parent = fwnode_graph_get_port_parent(asd_fwnode);
> >> +
> >> +	if (!is_of_node(sd->fwnode) || !is_of_node(asd_fwnode))
> >> +		return sd->fwnode == asd_fwnode ||
> >> +		       sd_parent == asd_fwnode ||
> >> +		       sd->fwnode == asd_parent;
> >>  
> >> -	return !of_node_cmp(of_node_full_name(to_of_node(sd->fwnode)),
> >> -			    of_node_full_name(
> >> -				    to_of_node(asd->match.fwnode.fwnode)));
> >> +	return match_fwnode_of(sd->fwnode, asd_fwnode) ||
> >> +	       match_fwnode_of(sd_parent, asd_fwnode) ||
> >> +	       match_fwnode_of(sd->fwnode, asd_parent);
> >>  }
> >>  
> >>  static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> > 
> > Would this become easier to read if you handled all matching in what is
> > called match_fwnode_of() above, also for non-OF fwnodes? Essentially you'd
> > have what used to be match_fwnode() there, and new match_fwnode() would call
> > that function with all the three combinations.
> > 
> 
> 
> > I'd call the other function __match_fwnode() for instance.
> > 
> 
> 
> Yes - Took me a moment to understand what you meant here - but yes it's leaner +
> cleaner:

Looks quite nice! Thanks! :)

> 
> 
> /*
>  * As a measure to support drivers which have not been converted to use
>  * endpoint matching, we also find the parent devices for cross-matching.
>  *
>  * When all devices use endpoint matching, this code can be simplified, and the
>  * parent comparisons can be removed.
>  */
> 
> static bool __match_fwnode(struct fwnode_handle *a, struct fwnode_handle *b)
> {
> 	if (is_of_node(a) || is_of_node(b))

I think you need && (not ||) although in practice I don't think it'd have
made any difference.

> 		return !of_node_cmp(of_node_full_name(to_of_node(a)),
> 				    of_node_full_name(to_of_node(b)));
> 	else
> 		return a == b;
> }
> 
> static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
> {
> 	struct fwnode_handle *asd_fwnode = asd->match.fwnode.fwnode;
> 	struct fwnode_handle *sd_parent, *asd_parent;
> 
> 	sd_parent = fwnode_graph_get_port_parent(sd->fwnode);
> 	asd_parent = fwnode_graph_get_port_parent(asd_fwnode);
> 
> 	return __match_fwnode(sd->fwnode, asd_fwnode) ||
> 	       __match_fwnode(sd_parent, asd_fwnode) ||
> 	       __match_fwnode(sd->fwnode, asd_parent);
> }
>
Sakari Ailus May 23, 2017, 9:43 p.m. UTC | #4
On Wed, May 24, 2017 at 12:40:19AM +0300, Sakari Ailus wrote:
> >  * When all devices use endpoint matching, this code can be simplified, and the
> >  * parent comparisons can be removed.

Oh, and this I'm not so sure about --- we'll need to match lens controllers
and flash drivers. There are no endpoints in those devices. Let's see how it
goes when we get there...
Kieran Bingham May 23, 2017, 9:47 p.m. UTC | #5
On 23/05/17 22:43, Sakari Ailus wrote:
> On Wed, May 24, 2017 at 12:40:19AM +0300, Sakari Ailus wrote:
>>>  * When all devices use endpoint matching, this code can be simplified, and the
>>>  * parent comparisons can be removed.
> 
> Oh, and this I'm not so sure about --- we'll need to match lens controllers
> and flash drivers. There are no endpoints in those devices. Let's see how it
> goes when we get there...
> 

Sure, would you like me to post a v4 of just this patch?

The parent checks should always be safe, so this feels like less of a workaround
now, and if it provides support for other use cases perhaps it could survive
longer term.
--
Kieran
Sakari Ailus May 23, 2017, 9:59 p.m. UTC | #6
On Tue, May 23, 2017 at 10:47:58PM +0100, Kieran Bingham wrote:
> On 23/05/17 22:43, Sakari Ailus wrote:
> > On Wed, May 24, 2017 at 12:40:19AM +0300, Sakari Ailus wrote:
> >>>  * When all devices use endpoint matching, this code can be simplified, and the
> >>>  * parent comparisons can be removed.
> > 
> > Oh, and this I'm not so sure about --- we'll need to match lens controllers
> > and flash drivers. There are no endpoints in those devices. Let's see how it
> > goes when we get there...
> > 
> 
> Sure, would you like me to post a v4 of just this patch?

Please.

> 
> The parent checks should always be safe, so this feels like less of a workaround
> now, and if it provides support for other use cases perhaps it could survive
> longer term.

Indeed. If you end up getting the second parent of a device node, the end
result will be that you simply won't have a match.
diff mbox

Patch

diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c
index cbd919d4edd2..12c0707851fd 100644
--- a/drivers/media/v4l2-core/v4l2-async.c
+++ b/drivers/media/v4l2-core/v4l2-async.c
@@ -41,14 +41,40 @@  static bool match_devname(struct v4l2_subdev *sd,
 	return !strcmp(asd->match.device_name.name, dev_name(sd->dev));
 }
 
+/*
+ * Check whether the two device_node pointers refer to the same OF node. We
+ * can't compare pointers directly as they can differ if overlays have been
+ * applied.
+ */
+static bool match_fwnode_of(struct fwnode_handle *a, struct fwnode_handle *b)
+{
+	return !of_node_cmp(of_node_full_name(to_of_node(a)),
+			    of_node_full_name(to_of_node(b)));
+}
+
+/*
+ * As a measure to support drivers which have not been converted to use
+ * endpoint matching, we also find the parent devices for cross-matching.
+ *
+ * When all devices use endpoint matching, this code can be simplified, and the
+ * parent comparisons can be removed.
+ */
 static bool match_fwnode(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)
 {
-	if (!is_of_node(sd->fwnode) || !is_of_node(asd->match.fwnode.fwnode))
-		return sd->fwnode == asd->match.fwnode.fwnode;
+	struct fwnode_handle *asd_fwnode = asd->match.fwnode.fwnode;
+	struct fwnode_handle *sd_parent, *asd_parent;
+
+	sd_parent = fwnode_graph_get_port_parent(sd->fwnode);
+	asd_parent = fwnode_graph_get_port_parent(asd_fwnode);
+
+	if (!is_of_node(sd->fwnode) || !is_of_node(asd_fwnode))
+		return sd->fwnode == asd_fwnode ||
+		       sd_parent == asd_fwnode ||
+		       sd->fwnode == asd_parent;
 
-	return !of_node_cmp(of_node_full_name(to_of_node(sd->fwnode)),
-			    of_node_full_name(
-				    to_of_node(asd->match.fwnode.fwnode)));
+	return match_fwnode_of(sd->fwnode, asd_fwnode) ||
+	       match_fwnode_of(sd_parent, asd_fwnode) ||
+	       match_fwnode_of(sd->fwnode, asd_parent);
 }
 
 static bool match_custom(struct v4l2_subdev *sd, struct v4l2_async_subdev *asd)