From: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
To: Cheng-yi Chiang <cychiang@chromium.org>
Cc: Taniya Das <tdas@codeaurora.org>,
"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS"
<devicetree@vger.kernel.org>,
ALSA development <alsa-devel@alsa-project.org>,
Banajit Goswami <bgoswami@codeaurora.org>,
Rob Herring <robh+dt@kernel.org>,
Stephan Gerhold <stephan@gerhold.net>,
Liam Girdwood <lgirdwood@gmail.com>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
Patrick Lai <plai@codeaurora.org>, Takashi Iwai <tiwai@suse.com>,
Tzung-Bi Shih <tzungbi@chromium.org>,
Stephen Boyd <swboyd@chromium.org>,
Tzung-Bi Shih <tzungbi@google.com>,
Andy Gross <agross@kernel.org>,
Rohit kumar <rohitkr@codeaurora.org>,
Mark Brown <broonie@kernel.org>,
Douglas Anderson <dianders@chromium.org>,
Dylan Reid <dgreid@chromium.org>,
Bjorn Andersson <bjorn.andersson@linaro.org>,
Judy Hsiao <judyhsiao@chromium.org>,
"moderated list:ARM/Mediatek SoC support"
<linux-arm-kernel@lists.infradead.org>
Subject: Re: [PATCH] ASoC: max98357a: set channels_max to 4
Date: Wed, 16 Jun 2021 11:23:36 -0500 [thread overview]
Message-ID: <7748e621-ba54-db90-6b56-23e006eb1dbe@linux.intel.com> (raw)
In-Reply-To: <CAFv8Nw+FNfmgwadeFMWjRiGbKFuO4JJ=9ggRHxG+Pq_OuHdmeA@mail.gmail.com>
>> I don't think it's correct to declare 4-channel support at the
>> individual codec DAI level when in practice each device will be provided
>> with a TDM mask that selects two slots.
>
> On this platform there is no TDM support, so there were two I2S data lines.
>
>>
>> This is confusing device capabilities and TDM link configuration.
>
> I see that in most of the use cases of multiple amps, we should use
> codecs and num_codecs of the link.
> But in this case we only want one codec to control the only GPIO
> shared by 4 max98357a amps
> I think we should be able to use 1 max98357 codec and 3 dummy codec to
> fulfill this use case.
> Not sure if the number of dummy codec would really matter.
> With num_codec > 1 we should be able to bypass the channel checking
> and just use the channel from CPU DAI.
Interesting, I haven't seen such 'multi-lane' solutions so far for I2S.
next prev parent reply other threads:[~2021-06-16 19:11 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-26 15:47 [PATCH] ASoC: max98357a: set channels_max to 4 Judy Hsiao
2021-06-01 6:20 ` Tzung-Bi Shih
2021-06-15 15:47 ` Cheng-yi Chiang
2021-06-15 16:00 ` Pierre-Louis Bossart
2021-06-16 10:14 ` Cheng-yi Chiang
2021-06-16 16:23 ` Pierre-Louis Bossart [this message]
2021-06-16 20:40 ` Mark Brown
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