Hi Kieran, On Thu, Apr 27, 2017 at 11:13:50PM +0100, Kieran Bingham wrote: > Hi Sakari, > > Thanks for taking a look
Sure! :-) > > On 27/04/17 22:43, Sakari Ailus wrote: > > Hi Kieran, > > > > Could I ask you to rebase your patches on top of my V4L2 fwnode patches > > here? > > > > <URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi> > > > > It depends on the fwnode graph patches, merged here: > > > > <URL:https://git.linuxtv.org/sailus/media_tree.git/log/?h=v4l2-acpi-merge> > > > > I expect the fwnode graph patches in v4.12 so we'll have them in media-tree > > master soon. > > > > (I'm pushing these branches right now, it may take a while until it's really > > there.) > > Sure, I'll merge those into my base. > > > On Thu, Apr 27, 2017 at 07:26:00PM +0100, Kieran Bingham wrote: > >> From: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com> > >> > >> Devices such as the the ADV748x support multiple parallel stream routes > >> through a single chip. This leads towards needing to provide multiple > >> distinct entities and subdevs from a single device-tree node. > >> > >> To distinguish these separate outputs, the device-tree binding must > >> specify each endpoint link with a unique (to the device) non-zero port > >> number. > >> > >> This number allows async subdev registrations to identify the correct > >> subdevice to bind and link. > >> > >> Signed-off-by: Kieran Bingham <kieran.bingham+rene...@ideasonboard.com> > >> --- > >> drivers/media/v4l2-core/v4l2-async.c | 7 +++++++ > >> drivers/media/v4l2-core/v4l2-subdev.c | 1 + > >> include/media/v4l2-async.h | 1 + > >> include/media/v4l2-subdev.h | 2 ++ > >> 4 files changed, 11 insertions(+) > >> > >> diff --git a/drivers/media/v4l2-core/v4l2-async.c > >> b/drivers/media/v4l2-core/v4l2-async.c > >> index 1815e54e8a38..875e6ce646ec 100644 > >> --- a/drivers/media/v4l2-core/v4l2-async.c > >> +++ b/drivers/media/v4l2-core/v4l2-async.c > >> @@ -42,6 +42,13 @@ static bool match_devname(struct v4l2_subdev *sd, > >> > >> static bool match_of(struct v4l2_subdev *sd, struct v4l2_async_subdev > >> *asd) > >> { > >> + /* > >> + * If set, we must match the device tree port, with the subdev port. > >> + * This is a fast match, so do this first > >> + */ > >> + if (sd->port && sd->port != asd->match.of.port) > > > > Zero is an entirely valid value for a port. I think it'd be good not to > > depend on non-zero port values for port matching. > > Well then that pretty much dashes my chances on not parsing the DT in the ADV > driver. Hmm. I guess there's no really a way to avoid it. But we could make it easier > > > > >> + return -1; > > > > Any particular reason to return -1 from a function with bool return type? > > Ahem, I clearly can't read ;-) > I think my mindset was thinking strcmp or something... But -1 is perfectly valid. If you wanted to make it look really interesting, you could return -!false and still have exactly the same functionality. ;-) > > > >> + > >> return !of_node_cmp(of_node_full_name(sd->of_node), > >> of_node_full_name(asd->match.of.node)); > >> } > >> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c > >> b/drivers/media/v4l2-core/v4l2-subdev.c > >> index da78497ae5ed..67f816f90ac3 100644 > >> --- a/drivers/media/v4l2-core/v4l2-subdev.c > >> +++ b/drivers/media/v4l2-core/v4l2-subdev.c > >> @@ -607,6 +607,7 @@ void v4l2_subdev_init(struct v4l2_subdev *sd, const > >> struct v4l2_subdev_ops *ops) > >> sd->flags = 0; > >> sd->name[0] = '\0'; > >> sd->grp_id = 0; > >> + sd->port = 0; > >> sd->dev_priv = NULL; > >> sd->host_priv = NULL; > >> #if defined(CONFIG_MEDIA_CONTROLLER) > >> diff --git a/include/media/v4l2-async.h b/include/media/v4l2-async.h > >> index 5b501309b6a7..2988960613ec 100644 > >> --- a/include/media/v4l2-async.h > >> +++ b/include/media/v4l2-async.h > >> @@ -56,6 +56,7 @@ struct v4l2_async_subdev { > >> union { > >> struct { > >> const struct device_node *node; > >> + u32 port; > > > > What if instead of storing the device's OF node, you'd store the port node > > and used that for matching? > > > > Would that also solve the problem or do I miss something? > > Actually - I was 'trying' to prevent having to parse the DT in the adv748x > driver if I didn't need to. > > Once I have to parse the DT, then yes, I think storing the endpoint node is > probably the best thing to compare against. > > And actually - you might have just solved my open question in the cover > letter ... > > I had got stuck in my mindset that if I were to use the endpoint 'leaf' node > as > a comparator - that it would be 'instead' of the root node. > > But actually - it could just be root-node + leaf-node to compare, which then > allows us the fallback of comparing just the root nodes if the leaf isn't set. > > I'll respin with this either tomorrow or early next week. Endpoints are indeed another option. Is there something that would prevent switching from device node matching to port / endpoint matching altogether? I don't think the driver changes should be difficult to make. Supporting different options there will be painful as it will likely require help from the driver to implement both --- separately. > > > > >> } of; > >> struct { > >> const char *name; > >> diff --git a/include/media/v4l2-subdev.h b/include/media/v4l2-subdev.h > >> index 0ab1c5df6fac..1c1731b491e5 100644 > >> --- a/include/media/v4l2-subdev.h > >> +++ b/include/media/v4l2-subdev.h > >> @@ -782,6 +782,7 @@ struct v4l2_subdev_platform_data { > >> * @ctrl_handler: The control handler of this subdev. May be NULL. > >> * @name: Name of the sub-device. Please notice that the name must be > >> unique. > >> * @grp_id: can be used to group similar subdevs. Value is driver-specific > >> + * @port: driver-specific value to bind multiple subdevs with a single DT > >> node. > >> * @dev_priv: pointer to private data > >> * @host_priv: pointer to private data used by the device where the subdev > >> * is attached. > >> @@ -814,6 +815,7 @@ struct v4l2_subdev { > >> struct v4l2_ctrl_handler *ctrl_handler; > >> char name[V4L2_SUBDEV_NAME_SIZE]; > >> u32 grp_id; > >> + u32 port; > >> void *dev_priv; > >> void *host_priv; > >> struct video_device *devnode; > > -- Kind regards, Sakari Ailus e-mail: sakari.ai...@iki.fi XMPP: sai...@retiisi.org.uk
