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[FEATURE] topology2: enable string concatenation for parameter passing #6985
Description
Is your feature request related to a problem? Please describe.
When including topology2 configuration files into a top-level file, where those included files don't only define classes but also instantiate objects, names in the included and in the including files have to match, which currently can only be achieved by hard-coding. Included files should be using parameters passed to them instead, which is unsupported ATM. See e8f170e#diff-3a76b3b9be741be592ab3e43fb13a010876f407a73bb8113c6f3851e84f5bd98R29 for examples of such hard-coding, e.g.
Object.PCM.pcm.210 {
name "Port0 Aux Playback"
id 210
Describe the solution you'd like
With topology1 / m4 we could pass parameters and then compose names by simply using parameters in strings like
define(`PIPELINE_ID', $2)
define(`N_BUFFER', `BUF'PIPELINE_ID`.'$1)
which would concatenate the string "BUF" with the value of the variable PIPELINE_ID which was set from the second parameter, a character '.' and the first parameter. That would then generate a string like "BUF20.1" for pipeline 20 and buffer ID 1.
Topology2 uses the alsaconf language which doesn't support this kind of string manipulation. To concatenate strings there something like
{
@func concat
strings [ "a1" "b2" "c3" ]
}
is used.
Describe alternatives you've considered
On the one hand alsaconf already has a way to concatenate strings described above - using @func concat, so supposedly we should use it too. OTOH I'm not even sure this is feasible in our case, but defining an additional string concatenation method for alsaconf seems wrong too.
Activity
ranj063 commentedon Jan 24, 2023
@lyakh fix posted upstream: alsa-project/alsa-utils#188
This fix doesnt use string concat but rather the compiler takes care of making sure that the objects in the included file have unique instance ID's
lyakh commentedon Jan 25, 2023
@ranj063 Thanks! Yes, that should solve this specific problem, but what about others? E.g. look at
sof/tools/topology/topology2/cavs-nocodec.conf
Lines 46 to 47 in 231622f
sof/tools/topology/topology2/cavs-nocodec.conf
Lines 55 to 56 in 231622f
jsarha commentedon Feb 13, 2025
So @lyakh you are looking for something like device-tree p-handle? A possibility to tag a topology object instance and refer to that tag in other parts of the topology, without need to refer to automatically assigned object names?