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 X-Spam-Level: X-Spam-Status: No, score=-2.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A8DC4C3A59B for ; Mon, 19 Aug 2019 08:43:35 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 77CF6206DF for ; Mon, 19 Aug 2019 08:43:35 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="sjJLj5ZY" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 77CF6206DF Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=bootlin.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender:Content-Type:Cc: List-Subscribe:List-Help:List-Post:List-Archive:List-Unsubscribe:List-Id: In-Reply-To:MIME-Version:References:Message-ID:Subject:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=g8ohhyqvUD+GH4UvUDC3cUGtATTGdxfhdASbv0Bme7o=; b=sjJLj5ZYULFPuNvba8RU7ZWoM rUUK/F5i2cE51P2NTkeOyaX5r0EBlkvv0uZRb+AXv5ZwV4Lt2orErcHAociTtCJwnIpCO8d/kbErJ rJiPb9Ss2vQZvaLZ571Ia9jW2WjbMGIWI017n4lmJAhA4gZE0+dp87vVTEHnNbg17vd5sNZDKAecO mqhMYaH+WFgnnMZZHPg1xN35qoB9HFM3cl6n0S5/sq3s9s0hX39gyMbvKu6fSfzeX7LFtowfthl+9 9C4JEL3t+PmuL8pA6T8h4LEkwDu+rXptFuVFEH6qcDANR3v1QZirPvl9xFQ0y+9XjCGIPWSGkk7UN wsDbncSGQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1hzdGD-0004Zj-8s; Mon, 19 Aug 2019 08:43:29 +0000 Received: from relay10.mail.gandi.net ([217.70.178.230]) by bombadil.infradead.org with esmtps (Exim 4.92 #3 (Red Hat Linux)) id 1hzdEY-0003Jw-8g for linux-arm-kernel@lists.infradead.org; Mon, 19 Aug 2019 08:41:48 +0000 Received: from localhost (lfbn-1-17395-211.w86-250.abo.wanadoo.fr [86.250.200.211]) (Authenticated sender: maxime.ripard@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 5242A240004; Mon, 19 Aug 2019 08:41:42 +0000 (UTC) Date: Mon, 19 Aug 2019 10:41:41 +0200 From: Maxime Ripard To: Mark Brown Subject: Re: Best representation for TDM devices Message-ID: <20190819084141.otpbos2fgxav7rco@flea> References: <20190801114807.GB5488@sirena.org.uk> <20190814160234.GG4640@sirena.co.uk> MIME-Version: 1.0 In-Reply-To: <20190814160234.GG4640@sirena.co.uk> User-Agent: NeoMutt/20180716 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190819_014146_738377_899F07CC X-CRM114-Status: GOOD ( 18.60 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Ali Burak =?utf-8?B?UGFyxLFt?= , linux-arm-kernel@lists.infradead.org Content-Type: multipart/mixed; boundary="===============5798455825696388967==" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org --===============5798455825696388967== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="dcfpx62fqgv2jqjo" Content-Disposition: inline --dcfpx62fqgv2jqjo Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable Hi Mark, On Wed, Aug 14, 2019 at 05:02:34PM +0100, Mark Brown wrote: > On Wed, Aug 14, 2019 at 12:53:24PM +0200, Ali Burak Par=C4=B1m wrote: > > On Thu, 1 Aug 2019 at 13:48, Mark Brown wrote: > > > On Thu, Aug 01, 2019 at 01:43:06PM +0200, Ali Burak Par=C4=B1m wrote: > > > > On Thu, Jul 25, 2019 at 03:01:12PM +0200, Maxime Ripard wrote: > > > > > Hardware is a custom board I designed with 4 PDM output microphones > > > > and 2 adau7002 devices as the codec for PDM-to-PCM. We want to do > > > > signal processing with this board. Therefore having separate stream= s for > > > > each microphone is crucial to the application though I am not sure = where > > > > we should implement this exactly. > > > > What is this processing - are the streams from these microphones > > > logically related in any way (eg, is this a microphone array)? There= 's > > > Yes, it is a microphone array application for speech enhancement. Thus, > > signal levels and physical time delays are important. > > > > probably going to be some overlap in the input signals at least. If = you > > > need to for example correlate different microphones then that's > > > relevant. > > > Yes, we correlate different microphone signals in some of our algorithm= s. > > OK, in that case I'd recommend providing them to userspace as a single > four channel stream - keeping everything bundled together as long as > possible to make it easier to keep the processing synced up. Ok, that's what I had in mind as well :) However, it looks like we can only capture as many channels as the max being exposed by the codec on the link? Any attempt at capturing something with 4 channels here using arecord was either reduced to two channels (the amount of channels provided by the adau7002 driver), or just refused by the ALSA core. Is there anything that we need to configure / work on to enable this? Maxime -- Maxime Ripard, Bootlin Embedded Linux and Kernel engineering https://bootlin.com --dcfpx62fqgv2jqjo Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iHUEABYIAB0WIQRcEzekXsqa64kGDp7j7w1vZxhRxQUCXVpgwQAKCRDj7w1vZxhR xY+TAP95lE8eBN7vztzKTn7/ox2b2yOAY/R+9IZAr6MhozTa7wEAtkB0vztpaSDp ETZvJkHOTQVRvG5/rW07h2wsZXLT6gQ= =GcTW -----END PGP SIGNATURE----- --dcfpx62fqgv2jqjo-- --===============5798455825696388967== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel --===============5798455825696388967==--