Re: [PATCH/RFC v9 04/19] mfd: max77693: adjust max77693_led_platform_data

[Jacek Anaszewski]

On 12/09/2014 11:04 AM, Lee Jones wrote:
> On Tue, 09 Dec 2014, Jacek Anaszewski wrote:
>
> > On 12/09/2014 09:50 AM, Lee Jones wrote:
> > > On Wed, 03 Dec 2014, Jacek Anaszewski wrote:
> > >
> > > > Add "label" array for Device Tree strings with the name of a LED device
> > > > and make flash_timeout a two element array, for caching the sub-led
> > > > related flash timeout. Added is also an array for caching pointers to the
> > > > sub-nodes representing sub-leds.
> > > >
> > > > Signed-off-by: Jacek Anaszewski <j.anaszewski@xxxxxxxxxxx>
> > > > Acked-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
> > > > Cc: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> > > > Cc: Lee Jones <lee.jones@xxxxxxxxxx>
> > > > ---
> > > >   include/linux/mfd/max77693.h |    4 +++-
> > > >   1 file changed, 3 insertions(+), 1 deletion(-)
> > > >
> > > > diff --git a/include/linux/mfd/max77693.h b/include/linux/mfd/max77693.h
> > > > index f0b6585..c80ee99 100644
> > > > --- a/include/linux/mfd/max77693.h
> > > > +++ b/include/linux/mfd/max77693.h
> > > > @@ -88,16 +88,18 @@ enum max77693_led_boost_mode {
> > > >   };
> > > >
> > > >   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.

Thanks for the hint.

Best Regards,
Jacek Anaszewski
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