Re: [PATCH] [RFC] of/platform: Make of_dev_node_match() helper public

From: Geert Uytterhoeven
Date: Fri May 05 2017 - 15:13:46 EST

Hi Rob,

On Fri, May 5, 2017 at 8:50 PM, Rob Herring <robh+dt@xxxxxxxxxx> wrote:
> On Fri, May 5, 2017 at 9:52 AM, Geert Uytterhoeven
> <geert+renesas@xxxxxxxxx> wrote:
>> Several drivers provide their own match functions, identical to
>> of_dev_node_match() in the OF platform core.
>> Reduce duplication by making of_dev_node_match() public.
>> To avoid conflicts, the duplicates in coresight and i2c must be removed
>> at the same time.
> I think you are down one level too far. At least the 2 users here are
> just for calls to bus_find_device. We already have a function for that

There are more of them, some used with driver_find_device().
class_find_device() need a slightly different version, as the data pointer
is const. E.g. drivers/spi/spi.c uses both variants...

device_find_child() can use the same callback.

> with of_find_device_by_node at least for platform devices. Perhaps
> rework that to be "struct device *of_find_bus_device_by_node(struct
> bus_type *b, struct device_node *np)" and then wrappers for each bus
> type. And perhaps make a class variant as well. However, we should
> also consider if OF is the right level. Maybe it should be fwnode
> functions?

There are only 2 of these:

$ git grep 'dev->fwnode == data'
drivers/iommu/arm-smmu-v3.c: return dev->fwnode == data;
drivers/iommu/arm-smmu.c: return dev->fwnode == data;

while you can find a few dozen of the OF callbacks.



Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@xxxxxxxxxxxxxx

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
-- Linus Torvalds