On 09/12/14 15:41, Lee Jones wrote:
>>>>>>>> struct max77693_led_platform_data {
>>>>>>>> > >>>>>>+ const char *label[2];
>>>>>>>> > >>>>>> u32 fleds[2];
>>>>>>>> > >>>>>> u32 iout_torch[2];for_each_available_child_of_node
>>>>>>>> > >>>>>> u32 iout_flash[2];
>>>>>>>> > >>>>>> u32 trigger[2];
>>>>>>>> > >>>>>> u32 trigger_type[2];
>>>>>>>> > >>>>>>+ u32 flash_timeout[2];
>>>>>>>> > >>>>>> u32 num_leds;
>>>>>>>> > >>>>>> u32 boost_mode;
>>>>>>>> > >>>>>>- u32 flash_timeout;
>>>>>>>> > >>>>>> u32 boost_vout;
>>>>>>>> > >>>>>> u32 low_vsys;
>>>>>>>> > >>>>>>+ struct device_node *sub_nodes[2];
>>>>>>> > >>>>>
>>>>>>> > >>>>>I haven't seen anyone do this before. Why can't you use the provided
>>>>>>> > >>>>>OF functions to traverse through your tree?
>>>>>> > >>>>
>>>>>> > >>>>I use for_each_available_child_of_node when parsing DT node, but I
>>>>>> > >>>>need to cache the pointer to sub-node to be able to use it later
>>>>>> > >>>>when it needs to be passed to V4L2 sub-device which is then
>>>>>> > >>>>asynchronously matched by the phandle to sub-node.
>>>>>> > >>>>
>>>>>> > >>>>If it is not well seen to cache it in the platform data then
>>>>>> > >>>>I will find different way to accomplish this.
>>>>> > >>>
>>>>> > >>>I haven't seen the end-driver for this, but why can't you use that
>>>>> > >>>device's of_node pointer?
>>>> > >>
>>>> > >>Maybe it is indeed a good idea. I could pass the of_node pointer
>>>> > >>and the sub-led identifier to the V4L2 sub-device and there look
>>>> > >>for the sub-node containing relevant identifier. The downside
>>>> > >>would be only that for_each_available_child_of_node would
>>>> > >>have to be called twice - in the led driver and in the V4L2 sub-device.
>>>> > >>I think that we can live with it.
>>> > >
>>> > >Are the LED and V4L2 drivers children of this MFD? If so, you can use
>>> > >the of_compatible attribute in struct mfd_cell to populate the each
>>> > >child's of_node dynamically i.e. the MFD core will do that for you.
>>> > >
>> >
>> > V4L2 driver wraps LED driver. This way the LED device can be
>> > controlled with use of two interfaces - LED subsystem sysfs
>> > and V4L2 Flash. This is the aim of the whole patch set.
>> >
>> > I've thought it over again and it seems that I will need to cache
>> > somewhere these sub_nodes pointers. They have to be easily accessible
>> > for the V4L2 sub-device as it can be asynchronously registered
>> > or unregistered within V4L2 media device. Sub-devices are matched
>> > basing on the sub-node phandle.
>
> Not quite getting this. Can you explain this in another way please?
Only the LED controller driver is a child the MFD. The LED controller
can contain multiple outputs with a physical LED attached to it. AFAICS
this binding is modelling each such an output as a the LED's controller
node child node.
I'm not sure though why storing the device node pointers is required,
rather than traversing OF tree when needed.
I guess we only need the list of the node pointer to populate struct
v4l2_async_subdev array for v4l2_async_notifier_register() call ?
--
Regards,
Sylwester
--
To unsubscribe from this list: send the line "unsubscribe linux-media" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
