Hi Sakari,
On 05/20/2015 04:31 PM, Sakari Ailus wrote:
Hi Jacek,
On Wed, May 20, 2015 at 03:47:25PM +0200, Jacek Anaszewski wrote:
...
--- a/drivers/leds/leds-aat1290.c
+++ b/drivers/leds/leds-aat1290.c
@@ -524,9 +524,8 @@ static int aat1290_led_probe(struct
platform_device *pdev)
led_cdev->dev->of_node = sub_node;
/* Create V4L2 Flash subdev. */
- led->v4l2_flash = v4l2_flash_init(fled_cdev,
- &v4l2_flash_ops,
- &v4l2_sd_cfg);
+ led->v4l2_flash = v4l2_flash_init(dev, NULL, fled_cdev,
+ &v4l2_flash_ops, &v4l2_sd_cfg);
Here the first argument should be led_cdev->dev, not dev, which is
&pdev->dev, whereas led_cdev->dev is returned by
device_create_with_groups (it takes dev as a parent) called from
led_classdev_register.
The reason for this is the fact that pdev->dev has its of_node
field initialized, which makes v4l2_async trying to match
subdev by parent node of a LED device, not by sub-LED related
DT node.
If v4l2_subdev->of_node is set, then it won't be replaced with one from
struct device. I.e. you need to provide of_node pointer only if it's
different from dev->of_node.
It will always be different since dev->of_node pointer is related
to the main DT node of LED device, whereas each LED connected to it
must be expressed in the form of sub-node, as
Documentation/devicetree/bindings/leds/common.txt DT states.
You can still refer to the device's root device_node using a phandle.
Why should I need to refer to the device's root node?
What I meant here was that DT documentation enforces that even if
there is a single LED connected to the device it has to be expressed
as a sub-node anyway. Each LED will have to be matched by the phandle
to the sub-node representing it. This implies that v4l2_subdev->of_node
(related to sub-LED DT node) will be always different from dev->of_node
(related to LED controller DT node).
Say, if you have a LED flash controller with an indicator. It's intended to
be used together with the flash LED, and the existing as3645a driver exposes
it through the same sub-device. I think that'd make sense with LED class
driver as well (i.e. you'd have two LED class devices but a single
sub-device). Small changes to the wrapper would be needed.
How the sub-device name should look like then? We would have to
concatenate somehow both LED class device names?
--
Best Regards,
Jacek Anaszewski
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