Hi,
On Dec 19 2016 20:08, Arnaud Pouliquen wrote:
Aim of this patch is to add 'Playback Channel Map' control to export audio capabilities in term of HDMI sink speakers allocation.
V3:
- "ASoC: hdmi-codec: add channel mapping control": => Minor fixes: - select stereo speaker config by default if HDMI cable unplugged - fix compilation warning.
- "DRM: add help to get ELD speaker allocation" => No delta vs V2.
- "ALSA pcm: allow non constant snd_pcm_chmap_elem" => No delta vs V2.
- "ASoC: core: add optional pcm_new callback for DAI driver" => No delta vs V2.
V2: In this version I use chmap helper functions from pcm_lib.c. It is quite tricky to use it from ASoC due to the relation chip of the controls with the pcm runtime. After several tries, my conclusion is that it must be handled in ASoC DAI driver. Main reason is that the DAI driver can not provide snd_pcm_chmap struct through kcontrol structure. But this induces that soc-core provides pcm runtime structure to DAI driver during probe.
Base on this conclusion. I reworked my patches by adding 2 new patches in patch-set
ALSA pcm: allow non constant snd_pcm_chmap_elem This patch allows to handle non constant channel mapping. As ELD information can change during runtime it is mandatory to properly handle the feature. In term of compatibility with legacy it should be straightforward, as update just consists in suppressing the 'const' constraint.
ASoC: core: add optional pcm_new callback for DAI driver This is the only way i found to be able to use snd_pcm_add_chmap_ctls and associated controls helper functions. From my point of view, this is the more simple way to add relationship between DAI and associated pcm devices. Notice that this patch, if accepted, makes the following one obsolete, as it also answer to the associated topic:
[PATCH v5 0/2] ALSA controls management using index/device/sub-devices fields (http://www.spinics.net/lists/alsa-devel/msg57639.html).
If you estimate that this it not reasonable i will come back to my first version.
V1: This patch follows discussion initiate here: [RFC] ASOC: HDMI audio info frame speaker allocation http://www.spinics.net/lists/alsa-devel/msg57363.html
The code is fully inspired from HDA driver. On hw_param, HDMI sink speaker capabilities are exported via TLV ops and a CEA allocation is choson, based on ELD information and the number of channels requested by user.
Mains differences with HDA implementation are:
- Control is read only
- Channel swap is not supported. Consequence is that unused channel in the mid of CEA audio infoframe channel mapping are considered as active. example for channel allocation 0x02: FL, FR, 0, FC) This configuration is only available for a 4 channels stream.
- Channel allocation table has been reordered and HDMI 2.0 is not supported.
Arnaud Pouliquen (4): DRM: add help to get ELD speaker allocation ALSA pcm: allow non constant snd_pcm_chmap_elem ASoC: core: add optional pcm_new callback for DAI driver ASoC: hdmi-codec: add channel mapping control
include/drm/drm_edid.h | 13 ++ include/sound/pcm.h | 4 +- include/sound/soc-dai.h | 3 + sound/core/pcm_lib.c | 6 +- sound/soc/codecs/hdmi-codec.c | 313 +++++++++++++++++++++++++++++++++++++++++- sound/soc/soc-core.c | 28 ++++ 6 files changed, 361 insertions(+), 6 deletions(-)
I'm sorry but please drop me from CC list. I'd like not to be involved into this kind of new integration within merge window of next Linux kernel, as I said to you.
Regards
Takashi Sakamoto