USE of ALSA to play audio on custom board

Hi,
I am Manish (Student) & I am new to this forum, Linux & also concept of ALSA. I am working on a custom board for vehicle infotainment which has a SOC which includes ARM & DSP cores in it. Linux would be the operating system on the ARM.
ARM & DSP communicate with each other on DSP BIOS link. DSP would be having various Audio Decoding, Encoding & Post processing engines.

I had a query that does ALSA require any DSP help for processing the audio like mixing, Volume control & so on.
How can ALSA help me to get the required audio out on the speakers. Does ALSA anyways communicate with DSP for its processing.
How can I interface the actual DAC with ALSA.
What would be the role of ALSA in my project? Do I really need to use the services of ALSA. Does it help me to read ther audio files directly from the CD or USB device or the SD card or do I need to use system calls to read the audio file?

Regards,
Manish

Alsa dont need DSP's help to run. Alsa can run fully on ARM.
Usualy Linux running in arm is in control of the Audio codec. If this is the case, then DSP cannot access the audio codec unless some arbitration mechanism is exclusively built by you in Linux kernel and DspBios.
But you can always use the DSP to process the audio read using alsa.

You can download alsa-utils source and see the amixer arecord and aplay code for more info .