[crojewsk-intel]

This PR is provided for testing purposes so that no regression occurs on sof-driver side and mirrors thread present on upstream. Once tested, PR will be closed.

Patchset aims to address format selection restrictions present currently in the HDAudio library. Formats which we are concerned about are 20 and 24 valid bits per sample within 32 bit depth container. One may identify them as S20_LE and S24_LE except that those, according to comments found in include/uapi/sound/asound.h, are for LSB-aligned scenarios. HDAudio streams expect MSB-aligned data, no matter if we are speaking of HOST (SDxFMT) or LINK (PPLCxFMT) side - chapter 4.5.1 of the public HDAudio specification. In short, S20_LE and S24_LE are invalid options.

Right now, given the implementation of snd_hdac_query_supported_pcm() within sound/hda/hdac_device.c, even if a codec responds with: "I support all possible formats specified within HDAudio specification", there will be no option to open a 20/32 or 24/32 stream. The kernel will force the stream to be opened using the highest available bit depth.

After discussing subject initially with Jaroslav and Takashi, suggestion was made to utilize 'subformat' option to address the problem. The eye-opening discussion begun much earlier though, in 2019 [1].

Paired with PRs for alsa-utils [2] and alsa-lib [3].


Flow of changes:

The very first patch adds MSBITS subformat options to allow for granular
20/32, 24/32 and 32/32 format selection. The next three make sure
subformat is actually honored during runtime. Most of that code is based
on format-related API.

Follow up is upgrade to the hda stream-format interface - several functions are added to make the granular format selection simple in the HDAudio world. Core of the implementation is based on the existing snd_hdac_calc_stream_format(). The next ten patches are straightforward switch from one interface to another with cleanup of now-unsed function as a finishing touch.

Last but not least - the avs-driver, on which the problem analyzed and debugged, is updated to no longer acknowledge S24_LE as a valid format option.

Changes in v1:

• fixed UBSAN due to missing snd_pcm_subformat_names[] entries for new subformats
• as HDMI stream capabilities are assigned on PCM open, patch 16/17 has been updated to ignore such codecs for now. A separate patchset will take care of this case
• params_bps() reworded to snd_pcm_hw_params_bps()
• fixed compilation issues in sof-driver, patch 13/17

[1]: https://lore.kernel.org/alsa-devel/20190905053302.9262-1-pawel.harlozinski@linux.intel.com/
[2]: alsa-project/alsa-utils#228
[3]: alsa-project/alsa-lib#342