On 12/05/15 17:56, Lars-Peter Clausen wrote: > On 05/08/2015 05:11 PM, Jonathan Cameron wrote: >> On 16/04/15 05:01, Robert Dolca wrote: >>> This patch adds a new function called iio_trigger_register_with_dev >>> which is a wrapper for iio_trigger_register. Besides the iio_trigger >>> struct this function requires iio_dev struct. It adds the trigger in >>> the device's trigger list and saves a reference to the device in the >>> trigger's struct. >>> >>> When the device is registered, in the trigger folder of the device >>> (where current_trigger file resides) a symlink is being created for >>> each trigger that was registered width iio_trigger_register_with_dev. >>> >>> # ls -l /sys/bus/iio/devices/iio:device0/trigger/ >>> total 0 >>> -rw-r--r-- 1 root root 4096 Apr 16 08:33 current_trigger >>> lrwxrwxrwx 1 root root 0 Apr 16 08:33 trigger0 -> ../../trigg >>> er0 >>> >>> This should be used for device specific triggers. Doing this the user space >>> applications can figure out what if the trigger registered by a specific device >>> and what should they write in the current_trigger file. Currently some >>> applications rely on the trigger name and this does not always work. >>> >>> This implementation assumes that the trigger is registered before the device is >>> registered. If the order is not this the symlink will not be created but >>> everything else will work as before. >>> >>> Signed-off-by: Robert Dolca <robert.dolca@xxxxxxxxx> >> I was rather hoping we'd get a few more comments on this. >> In principle I like the idea, but it's new ABI and does make life >> a tiny bit more complex, so what do people think? >> >> Few trivial code comments inline. > > I don't think it adds more information. Both the trigger and the > device get registered for the same parent device, so you can already > easily find the trigger for a device by going to the parent device > and taking a look at the triggers registered by the parent device. I had the same thought. The question is whether the slightly gain in simplicity for userspace is worth it... I'm undecided at the moment. -- To unsubscribe from this list: send the line "unsubscribe linux-iio" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
