From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 49FC5C433EF for ; Fri, 22 Apr 2022 11:28:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1442794AbiDVLbT (ORCPT ); Fri, 22 Apr 2022 07:31:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:42882 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232054AbiDVLbR (ORCPT ); Fri, 22 Apr 2022 07:31:17 -0400 Received: from hutie.ust.cz (hutie.ust.cz [185.8.165.127]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0703754F9F; Fri, 22 Apr 2022 04:28:22 -0700 (PDT) Content-Type: text/plain; charset=utf-8 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=cutebit.org; s=mail; t=1650626900; bh=nnRPoDn9UVOQmCSWBi2f0yPJ71M+pe94PUc3/C0TV6E=; h=Subject:From:In-Reply-To:Date:Cc:References:To; b=BAChplZkXMuMU7YQjAHHfzse8aIDAhSV5emQZaIx7Fr664MnS1WotKU9oMqA0G08L oXMJk5Zl8gsP1sytZjTBTyJAUSP9cPK8UoNsouQlgULCRve8jQJ5qZOdAtY4pCgwnh ywCL6HvHVjTcsUbT0ceA4vN62COm59lDp5Bn/fMM= Mime-Version: 1.0 (Mac OS X Mail 16.0 \(3696.80.82.1.1\)) Subject: Re: [RFC PATCH 0/5] Apple Macs machine-level ASoC driver From: =?utf-8?Q?Martin_Povi=C5=A1er?= In-Reply-To: Date: Fri, 22 Apr 2022 13:28:20 +0200 Cc: =?utf-8?Q?Martin_Povi=C5=A1er?= , Liam Girdwood , Rob Herring , Krzysztof Kozlowski , Jaroslav Kysela , Takashi Iwai , alsa-devel@alsa-project.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Mark Kettenis , Hector Martin , Sven Peter Content-Transfer-Encoding: quoted-printable Message-Id: References: <20220331000449.41062-1-povik+lin@cutebit.org> <6D199EAB-FE14-4030-96A7-2E0E89D25FAB@cutebit.org> To: Mark Brown Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org > On 22. 4. 2022, at 13:19, Mark Brown wrote: >=20 > On Fri, Apr 22, 2022 at 12:43:30PM +0200, Martin Povi=C5=A1er wrote: >=20 >> I looked in the TAS2770 and TAS2764 drivers/datasheets, and to answer >> the questions we had: >=20 >> * 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. >=20 >> * By default codecs transmit Hi-Z for duration of unused slots. >=20 >> So once we supply the devicetree props it should be electrically = sound >> under any configuration of userspace knobs. >=20 > Great, that's a relief. >=20 >> 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: >=20 >> 'I2C offset' -- uses a random slot >=20 >> 'Left' 'Right' 'LeftRight' -- uses the single slot we configured >=20 >> 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.) >=20 > 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=E2=80=99s 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.