From: "Martin Povišer" <povik@cutebit.org>
To: Mark Brown <broonie@kernel.org>
Cc: "Martin Povišer" <povik+lin@cutebit.org>,
"Liam Girdwood" <lgirdwood@gmail.com>,
"Rob Herring" <robh+dt@kernel.org>,
"Krzysztof Kozlowski" <krzk+dt@kernel.org>,
"Jaroslav Kysela" <perex@perex.cz>,
"Takashi Iwai" <tiwai@suse.com>,
alsa-devel@alsa-project.org, devicetree@vger.kernel.org,
linux-kernel@vger.kernel.org,
"Mark Kettenis" <kettenis@openbsd.org>,
"Hector Martin" <marcan@marcan.st>,
"Sven Peter" <sven@svenpeter.dev>
Subject: Re: [RFC PATCH 0/5] Apple Macs machine-level ASoC driver
Date: Fri, 22 Apr 2022 13:28:20 +0200 [thread overview]
Message-ID: <B68302F2-3D77-4065-8A16-A9CC690AE10B@cutebit.org> (raw)
In-Reply-To: <YmKPQ6kLCPz+2XTJ@sirena.org.uk>
> On 22. 4. 2022, at 13:19, Mark Brown <broonie@kernel.org> wrote:
>
> On Fri, Apr 22, 2022 at 12:43:30PM +0200, Martin Povišer wrote:
>
>> I looked in the TAS2770 and TAS2764 drivers/datasheets, and to answer
>> the questions we had:
>
>> * VSENSE/ISENSE output slots are configured independently of audio samples
>> routing. Kernel drivers configure the slots based on the 'ti,imon-slot-no'
>> and 'ti,vmon-slot-no' properties of devicetree.
>
>> * By default codecs transmit Hi-Z for duration of unused slots.
>
>> So once we supply the devicetree props it should be electrically sound
>> under any configuration of userspace knobs.
>
> Great, that's a relief.
>
>> One final thought on the playback routing controls: On systems with >2
>> speakers, the codecs need to be assigned slots through set_tdm_slot.
>> The macaudio driver RFCed here assigns a single slot to each speaker,
>> making the effect of each speaker's routing control this:
>
>> 'I2C offset' -- uses a random slot
>
>> 'Left' 'Right' 'LeftRight' -- uses the single slot we configured
>
>> I suppose I better assign two slots to speakers in each left-right pair
>> of the same kind (e.g. woofer 1, woofer 2, tweeter). This way the
>> routing control will mimic its behavior from simple stereo systems but
>> replicated within each left-right pair. (I would prefer to hide the
>> controls altogether, but as I learned that hiding things unless proven
>> dangerous is an ASoC non-goal, this way I can make the controls do
>> something interesting.)
>
> I don't quite grasp the difference between the arrangement you're
> proposing and assigning a single slot to each speaker? Possibly it's
> just a reordering of the slots?
Ah, maybe what’s missing is the fact that the way the speaker amp drivers
are written, if they are assigned two slots with a call to set_tdm_slot,
the first slot is considered 'left' and the second is 'right'.
So in the arrangement I am proposing the 'Left', 'Right' and 'LeftRight'
values of the routing control have the nominal effect (within the left-right
speaker pair), while in the other arrangement it is as I described above.
next prev parent reply other threads:[~2022-04-22 11:28 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-03-31 0:04 [RFC PATCH 0/5] Apple Macs machine-level ASoC driver Martin Povišer
2022-03-31 0:04 ` [RFC PATCH 1/5] dt-bindings: sound: Add Apple Macs sound system Martin Povišer
2022-03-31 6:43 ` Krzysztof Kozlowski
2022-03-31 6:57 ` Martin Povišer
2022-03-31 8:17 ` Krzysztof Kozlowski
2022-03-31 8:23 ` Martin Povišer
2022-03-31 8:26 ` Krzysztof Kozlowski
2022-03-31 0:04 ` [RFC PATCH 2/5] HACK: ASoC: Add card->filter_controls hook Martin Povišer
2022-03-31 11:34 ` Mark Brown
2022-03-31 0:04 ` [RFC PATCH 3/5] HACK: ASoC: Tolerate N-cpus-to-M-codecs links Martin Povišer
2022-04-04 12:28 ` Mark Brown
2022-04-22 14:06 ` Martin Povišer
2022-04-25 12:25 ` Mark Brown
2022-04-25 12:34 ` Martin Povišer
2022-04-25 12:55 ` Mark Brown
2022-04-25 13:11 ` Martin Povišer
2022-04-25 13:46 ` Mark Brown
2022-04-25 13:55 ` Martin Povišer
2022-03-31 0:04 ` [RFC PATCH 4/5] ASoC: Introduce snd_soc_of_get_dai_link_cpus Martin Povišer
2022-03-31 0:04 ` [RFC PATCH 5/5] ASoC: Add macaudio machine driver Martin Povišer
2022-03-31 11:59 ` Mark Brown
2022-03-31 12:08 ` Martin Povišer
2022-03-31 12:16 ` Martin Povišer
2022-03-31 12:56 ` Mark Brown
2022-03-31 12:34 ` [RFC PATCH 0/5] Apple Macs machine-level ASoC driver Mark Brown
2022-03-31 13:28 ` Martin Povišer
2022-03-31 14:18 ` Mark Brown
2022-03-31 15:04 ` Martin Povišer
2022-03-31 15:36 ` Mark Brown
2022-04-22 10:43 ` Martin Povišer
2022-04-22 11:19 ` Mark Brown
2022-04-22 11:28 ` Martin Povišer [this message]
2022-04-22 11:33 ` Mark Brown
2022-04-22 11:44 ` Martin Povišer
2022-04-22 12:22 ` Mark Brown
2022-04-22 12:36 ` Martin Povišer
2022-04-22 12:44 ` Mark Brown
2022-04-22 12:53 ` Martin Povišer
2022-04-22 13:06 ` Mark Brown
2022-04-22 13:59 ` Martin Povišer
2022-03-31 13:28 ` Hector Martin
2022-03-31 14:33 ` Mark Brown
2022-04-05 9:31 ` (subset) " Mark Brown
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