On 05/08/2014 11:04 AM, Sakari Ailus wrote: > Heippa! > > On Wed, May 07, 2014 at 03:57:11PM +0300, Antti Palosaari wrote: >> What is preferred way implement controls that could have some known >> unit or unknown unit? For example for gain controls, I would like to >> offer gain in unit of dB (decibel) and also some unknown driver >> specific unit. Should I two controls, one for each unit? >> >> Like that >> >> V4L2_CID_RF_TUNER_LNA_GAIN_AUTO >> V4L2_CID_RF_TUNER_LNA_GAIN >> V4L2_CID_RF_TUNER_LNA_GAIN_dB > > I suppose that on any single device there would be a single unit to control > a given... control. Some existing controls do document the unit as well but > I don't think that's scalable nor preferrable. This way we'd have many > different controls to control the same thing but just using a different > unit. The auto control is naturally different. Hans did have a patch to add > the unit to queryctrl (in the form of QUERY_EXT_CTRL). Well, that's going to be dropped again. There were too many comments about that during the mini-summit and it was not critical for me. > > <URL:http://www.spinics.net/lists/linux-media/msg73136.html> > > I wish we can get these in relatively soon. Sakari, I think you will have to push this if you want this done. One interesting thing to look at: the AVB IEEE 1722.1 standard has extensive support for all sorts of units. I don't know if you have access to the standard document, but it might be interesting to look at what they do there. Regards, Hans -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
