On Thu, Dec 3, 2015 at 1:36 AM, sturmflut <sturmf...@lieberbiber.de> wrote: > Dear list, > > I've been looking at the necessary pieces for FM radio support, and I > hope somebody can correct me, but it looks more complicated than I expected. >
We discussed this topic lengthily on the list some time ago :) It's not like we don't want to support FM radio, but the lack of a common Android HAL for FM radio access would force us to maintain an FM radio abstraction ourselves (more on that below). In addition, most of the device-specific radio apps require elevated privileges to run as they directly access the FM radio HW (not multiplexed by a system service). > For some reason Android doesn't have an FM radio API and leaves it up to > the manufacturers to come up with something. I've looked at several > devices, among them the bq Aquaris E4.5, and every SoC manufacturer > seems to have a different opinion on how to do it. > > Some ship no FM radio at all. > > Some seem to ship drivers for the Linux V4L subsystem. > > MediaTek (Aquaris E4.5 and E5) decided to implement custom kernel > drivers with a custom character device (/dev/fm) and custom ioctl > commands. There seem to be userspace libraries (libfm*) including a JNI > wrapper in /system/lib of the Android container on our Ubuntu phones. > > Because there is no standard API, there are no generic FM radio apps for > Android, and pretty much every manufacturer ships a custom app for his > own SoC(s) and/or device(s). > > > I'll try to come up with a piece of C code for the command line that can > at least initialize and tune the FM radio on the Aquaris E4.5 and E5. > The long-term goal could be to turn this into plugins for an extended > media-hub. > If you are interested in helping to enable the functionality, the correct chain for integrating the feature would be: [1.] Add a (potentially limited) API to lp:platform-api, that exposes a simple common C interface to the Ubuntu side. [2.] Provide an implementation of the API in platform-api/android (see http://bazaar.launchpad.net/~phablet-team/platform-api/trunk/files/head:/android/) [2.1] Provide a dummy fallback implementation for devices that do not support FM radio of any kind. [3.] Expose the respective hardware functionality to media-hub. Multiple ways are possible, but we would need to significantly adjust the interfaces to support fm radio semantics (switching stations, rds, automatic scans etc.) [4.] Adjust Qt's radio abstraction and come up with a Ubuntu Touch specific backend implementation, that either: [4.1] Leverages the API in [1.] directly (would require any app to have special privileges in accessing the system). [4.2] Leverages the API in [3.] (which is the clean way of integration FM radio support). For starters, [1.], [2.], [2.1] and [4.1] should be good enough to get started. Cheers, Thomas > > cheers, > Simon > > -- > Mailing list: https://launchpad.net/~ubuntu-phone > Post to : ubuntu-phone@lists.launchpad.net > Unsubscribe : https://launchpad.net/~ubuntu-phone > More help : https://help.launchpad.net/ListHelp -- Mailing list: https://launchpad.net/~ubuntu-phone Post to : ubuntu-phone@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-phone More help : https://help.launchpad.net/ListHelp
