Arnd,
On 05/26/2011 08:11 AM, Arnd Bergmann wrote:
On Wednesday 25 May 2011, Rob Herring wrote:
From: Rob Herring<[email protected]>
Add support to the platform bus scanning to call custom device creation
functions. This enables creation of non-platform devices like amba_bus.
Cc: Jeremy Kerr<[email protected]>
Cc: Grant Likely<[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: Linus Walleij<[email protected]>
Signed-off-by: Rob Herring<[email protected]>
This creates a confusing mix of match table entries: Normally,
all entries in the match table are meant to identify child buses,
but if I read your patch correctly, you now also need to match
on the amba devices themselves, including the creation of
platform devices for each child device node under an amba
device.
We should only create devices for each matching bus and the immediate
children of each bus. A child device of an amba device would be
something like an i2c bus which we don't want to create devices for. Or
am I missing something?
I don't think that was the intention. Maybe we need to pass
two match tables into of_platform_bus_probe() instead:
one to identify the buses, and another one that is used
to create the actual devices.
That was my original thinking too, but some reason I had concluded 1
could get by with just 1 table. After more thought, I think you are
right. In fact, I broke platform device creation with this patch. I need
to be able to tell if no match means create a platform device (child of
bus) or not (child of a device).
Here's an updated version with just the interesting hunk. I've tested it
with a made up bus structure that looks something like this:
soc bus
-plat dev
-amba dev
-sub-bus
-plat dev
-amba dev
-plat dev
As of_platform_bus_probe is not recommended to be used by Grant, I only
plan to add 2 match tables to of_platform_bus_populate.
@@ -234,18 +237,32 @@ static int of_platform_bus_create(struct
device_node *bus,
return 0;
}
- dev = of_platform_device_create(bus, NULL, parent);
- if (!dev || !of_match_node(matches, bus))
- return 0;
-
- for_each_child_of_node(bus, child) {
- pr_debug(" create child: %s\n", child->full_name);
- rc = of_platform_bus_create(child, matches, &dev->dev, strict);
- if (rc) {
- of_node_put(child);
- break;
+ id = of_match_node(bus_matches, bus);
+ if (id) {
+ dev = of_platform_device_create(bus, NULL, parent);
+ if (!dev)
+ return 0;
+ for_each_child_of_node(bus, child) {
+ pr_debug(" create child: %s\n", child->full_name);
+ rc = of_platform_bus_create(child, bus_matches,
+ dev_matches, dev, strict);
+ if (rc) {
+ of_node_put(child);
+ break;
+ }
}
+ return rc;
}
+
+ id = of_match_node(dev_matches, bus);
+ mdata = id ? id->data : NULL;
+ if (id && mdata && mdata->dev_create)
+ dev = mdata->dev_create(bus, parent);
+ else
+ dev = of_platform_device_create(bus, NULL, parent);
+ if (!dev)
+ return 0;
+
return rc;
}
Rob
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