[alsa-devel] [RFC PATCH] ucm: Add support for device positions

[Mengdong Lin]

On 01/03/2017 04:21 PM, Vinod Koul wrote:
> On Tue, Jan 03, 2017 at 02:09:18PM +0800, mengdong.lin at linux.intel.com wrote:
>> From: Mengdong Lin <mengdong.lin at linux.intel.com>
>>
>> Users can provide prosition info of audio devices as a device value. This
>> will help the sound server to choose an audio devices from some candidates
>> based on the their locations and the status of the machine.
>
> This is good thing to have but some bits are bit unclear to me atm. When you
> say device, do you mean sound card?

No, the device here does not mean a sound card, but mean an I/O device 
like speaker or dmic, defined by 'SectionDevice'.

> For me, position makes sense for dmics and speakers. So can you help me out
> by understanding how we can describe these...
>

For example, if there are two DMICs, one is in the front and one on the 
back, we can define their positions as below:

SectionDevice."MainMIC" {

        ...

         EnableSequence [
                ...
         ]

         DisableSequence [
                 ...
         ]

         Value {
                 Position "Front"
         }
}

SectionDevice."SecondaryMIC" {

	...

	EnableSequence [
	...
	]

	DisableSequence [
	...
	]

	Value {
		Position "Back"
	}
}


Thanks
Mengdong