From: Peter Ujfalusi <peter.ujfalusi@ti.com>
To: Tony Lindgren <tony@atomide.com>
Cc: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>,
Mark Brown <broonie@kernel.org>,
Liam Girdwood <lgirdwood@gmail.com>,
Jaroslav Kysela <perex@perex.cz>, Takashi Iwai <tiwai@suse.com>,
"alsa-devel@alsa-project.org" <alsa-devel@alsa-project.org>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-omap@vger.kernel.org" <linux-omap@vger.kernel.org>,
Sebastian Reichel <sre@kernel.org>,
Jarkko Nikula <jarkko.nikula@bitmer.com>
Subject: Re: [PATCH 0/2] Graph fixes for using multiple endpoints per port
Date: Thu, 13 Dec 2018 08:53:38 +0200 [thread overview]
Message-ID: <34191403-3c56-47ac-77d9-e900d88f2ae5@ti.com> (raw)
In-Reply-To: <20181212145022.GB6707@atomide.com>
On 12/12/2018 16.50, Tony Lindgren wrote:
> * Peter Ujfalusi <peter.ujfalusi@ti.com> [181212 13:03]:
>> On 12/12/2018 2.19, Tony Lindgren wrote:
>>> In my McBSP case there is only a single physical I2S port
>>> that can be TDM split into timeslots.
>>
>> So what is missing from the McBSP driver is to configure the TDM. We
>> never had a hardware which would require it so it is _not_ implemented.
>
> Curiously.. Nothing needs to be done in the McBSP driver for the droid
> 4 TDM configuration AFAIK.
So you always have 4 timeslot and that's it?
> The CPCAP PMIC is the clock master, and only the PMIC registers need to
> be configured in this case for the timeslot to switch between codecs
> connected to McBSP3.
The McBSP TDM configuration is not master only.
You basically tell McBSP on which timeslot to transmit/receive.
Let's say you have two codecs connected to a single McBSP.
codec1 is configured to listen for timeslot 0/1
codec2 is configured to listen for timeslot 2/3
If you open a stereo stream to codec1 then you tell McBSP to
send/receive the data under timeslot 0/1 and ignore any other timeslots.
If you open a stereo stream to codec2 then you tell McBSP to
send/receive the data under timeslot 2/3 and ignore any other timeslots.
For codec1 you don't really need anything regarding to TDM configuration
as McBSP will send/receive right after the start condition on the FS,
but for codec2 you need to configure the TDM mode of McBSP to ignore
timeslot 0/1
>> imho the 'only' thing is to implement the set_tdm_slot callback for the
>> McBSP DAI. In DT you would have single card with two dai_link section
>> and each section would set different tdm slots to use for the codecs
>> listening on different slots.
>>
>> There is one issue for sure with this setup: the two PCM can not be used
>> at the same time. But we have one DMA channel so if you would open both
>> the PCM stream need to be set up in a way to match with the HW or create
>> a asound.conf file to do some mapping.
>
> Yes in the droid 4 TDM case only one device can be used at a time
> and all that configuration is done in the PMIC codec .set_tdm_slot
> function.
Hrm, do you have two DAIs on the PMIC side or different timeslots from
the TDM stream is routed to different outputs, similarly to twl6040
where timeslot 0/1 is Headset, timeslot 2/3 is Handsfree and timeslot 5
is to drive a vibra?
> I think it's possible to do more complex configurations where McBSP
> is the master and would implement a .set_tdm_slot function. But I
> don't know anything about that and I'm not aware of any such use
> cases in the mainline kernel.
No, the set_tdm_slot is applicable for both master and slave mode of McBSP.
>
> Regards,
>
> Tony
>
- Péter
Texas Instruments Finland Oy, Porkkalankatu 22, 00180 Helsinki.
Y-tunnus/Business ID: 0615521-4. Kotipaikka/Domicile: Helsinki
next prev parent reply other threads:[~2018-12-13 6:52 UTC|newest]
Thread overview: 29+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-12-11 2:05 [PATCH 0/2] Graph fixes for using multiple endpoints per port Tony Lindgren
2018-12-11 2:05 ` [PATCH 1/2] ASoC: simple-card-utils: revert port changes to follow graph binding Tony Lindgren
2018-12-11 2:05 ` [PATCH 2/2] ASoC: audio-graph-card: Fix parsing of multiple endpoints Tony Lindgren
2018-12-11 3:31 ` [PATCH 0/2] Graph fixes for using multiple endpoints per port Kuninori Morimoto
2018-12-11 4:52 ` Tony Lindgren
2018-12-11 5:16 ` Kuninori Morimoto
2018-12-11 5:30 ` Kuninori Morimoto
2018-12-11 5:44 ` Tony Lindgren
2018-12-11 5:35 ` Tony Lindgren
2018-12-11 6:14 ` Kuninori Morimoto
2018-12-11 14:16 ` Tony Lindgren
2018-12-11 23:16 ` Kuninori Morimoto
2018-12-12 0:12 ` Kuninori Morimoto
2018-12-12 0:43 ` Tony Lindgren
2018-12-12 0:50 ` Tony Lindgren
2018-12-12 0:19 ` Tony Lindgren
2018-12-12 2:11 ` Kuninori Morimoto
2018-12-12 6:51 ` [alsa-devel] " Kuninori Morimoto
2018-12-12 15:27 ` Tony Lindgren
2018-12-13 0:24 ` Kuninori Morimoto
2018-12-13 0:40 ` Tony Lindgren
2018-12-13 1:06 ` Kuninori Morimoto
2018-12-13 1:13 ` Tony Lindgren
2018-12-12 13:05 ` Peter Ujfalusi
2018-12-12 14:50 ` Tony Lindgren
2018-12-13 6:53 ` Peter Ujfalusi [this message]
2018-12-13 16:55 ` Tony Lindgren
2018-12-12 12:48 ` Peter Ujfalusi
2018-12-12 14:58 ` Tony Lindgren
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=34191403-3c56-47ac-77d9-e900d88f2ae5@ti.com \
--to=peter.ujfalusi@ti.com \
--cc=alsa-devel@alsa-project.org \
--cc=broonie@kernel.org \
--cc=jarkko.nikula@bitmer.com \
--cc=kuninori.morimoto.gx@renesas.com \
--cc=lgirdwood@gmail.com \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-omap@vger.kernel.org \
--cc=perex@perex.cz \
--cc=sre@kernel.org \
--cc=tiwai@suse.com \
--cc=tony@atomide.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).