feat(linux): Add audio-graph-card2 documentation - #759
Open
SenWang125 wants to merge 1 commit into
Open
Conversation
SenWang125
requested review from
StaticRocket,
VeeruPrudhvi,
cshilwant,
gehariprasath,
jeevantelukula,
praneethbajjuri and
uditkumarti
as code owners
July 28, 2026 01:33
github-actions
Bot
assigned
devarsht,
gehariprasath,
praneethbajjuri,
r-vignesh and
uditkumarti
SenWang125
force-pushed
the
audio-graph-card2_doc
branch
3 times, most recently
from
July 28, 2026 01:40
686403c to
aa6c5b6
Compare
SenWang125
marked this pull request as draft
July 28, 2026 01:57
SenWang125
marked this pull request as ready for review
July 28, 2026 01:58
SenWang125
force-pushed
the
audio-graph-card2_doc
branch
2 times, most recently
from
July 28, 2026 02:45
3b86ae0 to
f2ce624
Compare
devarsht
reviewed
Jul 28, 2026
|
|
||
| In this configuration: | ||
|
|
||
| * The two FE ports on the McASP node (``port@0``/``port@1``) use the same flat, non-DPCM ``ports`` binding as the previous example. DPCM fan-out is defined on the **card** side, in the ``dpcm`` sub-node, not on the McASP node itself |
Collaborator
There was a problem hiding this comment.
What do you mean by FE port?
devarsht
reviewed
Jul 28, 2026
|
|
||
| In this configuration: | ||
|
|
||
| * One McASP DAI serves both codec links (here, a headphone codec and HDMI), each exposed as its own ``port@N`` endpoint under the McASP node's ``ports`` container |
Collaborator
There was a problem hiding this comment.
Good to give execution steps too, ideally an overlay would have been better.
- User applies this DT change
- User plays using TLV codec path -> steps and cmd
- User wants to play HDMI audio -> steps (Jumper change) and cmd to select hdmi dai link
devarsht
reviewed
Jul 28, 2026
|
|
||
| ``simple-audio-card`` can already share one McASP instance across multiple independent codec links (see | ||
| the ``simple-audio-card`` multi-codec example above), using its ``cpu``/``codec`` phandle pairs. | ||
| **audio-graph-card2** describes the same kind of topology through the generic OF-graph ``ports``/``port`` |
Collaborator
There was a problem hiding this comment.
Highlight when user should switch to audio graph card2 and what are its advantages .
I think it helps avoid a system reboot when switching form tlv to HDMI codec as you had mentioned earlier as user just need to change the jumper right?
StaticRocket
requested changes
Jul 28, 2026
StaticRocket
left a comment
StaticRocket
left a comment
Member
There was a problem hiding this comment.
There are quite a few acronyms that are never actually defined in this document
| - No :sup:`1` | ||
| - | A fixed multiplier to sampling rate (𝑓\ :sub:`s`) for a given AUXCLK frequency for TX (and RX if ``auxclk-fs-ratio-rx`` not specified). | ||
| | :sup:`1` If not specified, dividers are calculated from ``.set_sysclk`` via the ASoC machine driver. (For common machine driver such as simple-audio-card or audio-graph-card, this is set via the ``system-clock-frequency = <>`` property in the DAI link). | ||
| | :sup:`1` If not specified, dividers are calculated from ``.set_sysclk`` via the ASoC machine driver. (For common machine driver such as simple-audio-card, audio-graph-card, or audio-graph-card2, this is set via the ``system-clock-frequency = <>`` property in the DAI link or endpoint). |
Member
There was a problem hiding this comment.
Suggested change
| | :sup:`1` If not specified, dividers are calculated from ``.set_sysclk`` via the ASoC machine driver. (For common machine driver such as simple-audio-card, audio-graph-card, or audio-graph-card2, this is set via the ``system-clock-frequency = <>`` property in the DAI link or endpoint). | |
| | :sup:`1` If not specified, dividers are calculated from ``.set_sysclk`` via the ASoC machine driver. The ``system-clock-frequency`` property in the DAI link or endpoint sets this value for common machine drivers such as simple-audio-card, audio-graph-card, or audio-graph-card2). |
| Most TI EVMs use simple-audio-card for its simplicity, though audio-graph-card or custom machine drivers are also supported. | ||
| Most TI EVMs use simple-audio-card for its simplicity, though audio-graph-card2 or custom machine drivers are also supported. | ||
| audio-graph-card2 describes DAI links through the generic OF-graph ``ports``/``port``/``endpoint`` bindings | ||
| on the McASP node instead of ``simple-audio-card``'s ``cpu``/``codec`` phandle pairs (see the example |
Member
There was a problem hiding this comment.
Hm. The term phandle seems to be a colloquialism in the kernel for device tree references. It's well known enough to be used in the bindings, but not actually described in their documentation. Fun. Guess we should incorporate it in the accept list?
Comment on lines
+351
to
+352
| on the McASP node instead of ``simple-audio-card``'s ``cpu``/``codec`` phandle pairs (see the example | ||
| below). It also handles a DPCM (Dynamic PCM) topology, where one front-end stream fans out to, or fans in from, more |
Member
There was a problem hiding this comment.
Suggested change
| on the McASP node instead of ``simple-audio-card``'s ``cpu``/``codec`` phandle pairs (see the example | |
| below). It also handles a DPCM (Dynamic PCM) topology, where one front-end stream fans out to, or fans in from, more | |
| on the McASP node instead of ``simple-audio-card``'s ``cpu``/``codec`` phandle pairs (see the following | |
| example). It also handles a DPCM (Dynamic PCM) topology, where one front-end stream fans out to, or fans in from, more |
Signed-off-by: Sen Wang <sen@ti.com>
SenWang125
force-pushed
the
audio-graph-card2_doc
branch
from
July 28, 2026 21:29
f2ce624 to
d0289dd
Compare
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
7 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Adding audio-graph-card2 support documentation as a part of McASP and its machine driver binding specifics.