On Mon, Sep 11, 2017 at 03:34:16PM +0200, Hans Verkuil wrote: > >>>>> + u32 val; > >>>>> + > >>>>> + fwnode_for_each_child_node(fwnode, child) { > >>>>> + if (fwnode_property_read_u32(child, *props, &val)) > >>>>> + continue; > >>>>> + > >>>>> + if (val == *args) > >>>>> + break; > >>>> > >>>> I'm lost. This really needs comments and perhaps even an DT or ACPI example > >>>> so you can see what exactly it is we're doing here. > >>> > >>> I'll add comments to the code. A good example will be ACPI documentation > >>> for LEDs, see 17th patch in v9. That will go through the linux-pm tree so > >>> it won't be available in the same tree for a while. > >> > >> Ideally an ACPI and an equivalent DT example would be nice to have, but I might > >> be asking too much. I'm not that familiar with ACPI, so for me a DT example > >> is easier. > > > > This won't be useful on DT although you could technically use it. In DT you > > can directly refer to any node but on ACPI you can just refer to devices, > > hence this. > > So this function will effectively only be used with acpi? That should be > documented. I think that explains some of my confusion since I was trying > to map this code to a device tree, without much success. I'll add to the documentation of the function: * While it is technically possible to use this function on DT, it is only * meaningful on ACPI. On Device tree you can refer to any node in the tree but * on ACPI the references are limited to devices. > > > Would you be happy with the leds.txt example? I think it's a good example > > as it's directly related to this. > > Yes, that will work. I'll add a separate patch that I'll post later on. The ACPI documentation should get merged first. -- Sakari Ailus e-mail: sakari.ailus@xxxxxx -- To unsubscribe from this list: send the line "unsubscribe devicetree" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html