Hi,
On 03/12/2015 08:33 PM, Belisko Marek wrote:
Hi,
I posted same question on alsa-devel ML this week but I forgot to add sound omap + asoc maintainers (sorry about that)
I'm trying to add audio support for gta04 (for gsm + bt and fm audio). All audio sources are clock masters so basically connection is dummy codecs -> cpu dai (mcbsp ports).
The FM seams to be slave device (Si4705/Si4721) on the I2S bus. But in any of the cases (FM, GSM and BT) how do you configure the DAI formats of the 'codecs'? Si47xx has support for I2S, L_JUST and DSP mode for example. What about the sample formats and rates? I think there should be a driver for at least the FM. For BT there is a bt-sco codec driver but w/o DT support.
For implementing such thing I can see 2 options:
- simple card driver which can easily describe cpu dai interface but
dummy codec cannot because there are no DT bindings (there was sever attempts to add DT bindings for dummy-codec but AFAIK none was accepted)
Yes, the dummy-codec is Linux/ASoC concept and should not be described in DT. However I think there should be a way to describing passive DAIs. Slave devices only listening, or masters streaming the data. But, I think even if you have such a device you do have some control, at least to enable/disable them...
This turns it to only solution to create gta04 soundcard which will get from DT cpu dai links and use in card driver dummy codecs directly.
I would look up the driver for the FM and write the codec driver for it, probably the same can be done for the GSM and add bindings for the bt-sco so all of this can work with simple-card. Or write a custom machine driver and get it done ;)
Is my assumption correct? I would like to get some feedback before wasting my time with implementing something which cannot be pushed mainline. Thanks for all suggestions.
BR,
marek
-- as simple and primitive as possible
Marek Belisko - OPEN-NANDRA Freelance Developer
Ruska Nova Ves 219 | Presov, 08005 Slovak Republic Tel: +421 915 052 184 skype: marekwhite twitter: #opennandra web: http://open-nandra.com