From patchwork Fri Feb 17 12:41:48 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Claudiu Beznea X-Patchwork-Id: 1744218 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=2620:137:e000::1:20; helo=out1.vger.email; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Authentication-Results: legolas.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=microchip.com header.i=@microchip.com header.a=rsa-sha256 header.s=mchp header.b=hl2JQTef; dkim-atps=neutral Received: from out1.vger.email (out1.vger.email [IPv6:2620:137:e000::1:20]) by legolas.ozlabs.org (Postfix) with ESMTP id 4PJBKH2JYMz23j7 for ; Fri, 17 Feb 2023 23:42:11 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229598AbjBQMmJ (ORCPT ); Fri, 17 Feb 2023 07:42:09 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:44470 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229491AbjBQMmI (ORCPT ); Fri, 17 Feb 2023 07:42:08 -0500 Received: from esa.microchip.iphmx.com (esa.microchip.iphmx.com [68.232.154.123]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id CB23A64B23; Fri, 17 Feb 2023 04:42:04 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=microchip.com; i=@microchip.com; q=dns/txt; s=mchp; t=1676637724; x=1708173724; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=U2iLnm4KuI3Sgwn+ds9QR6hu9ocdgvXPg7MffzvqL48=; b=hl2JQTefPHUPZfv24BOnO3f15TWJoL5f095xBX1d7SZtTbHJMa3O1vOz ybSsBpRK/ll7WbWHEVUEBI7bGrNY3B/wONULA80fZ61RcEQ5EuIwyxQHe MRBTSGB5AiNpNhjGo4rDhwKgx+f2sMTqUROaAOYmypqYZYbXMvUR/UVRa eyigjwdWoMq+Vcwy/EdSQNTD6yudIgsIgpmnOhezj8PrrHa9sgQX9q2q+ dHCAybjvjMs65b2NaF7sTRd4JCV7FbqNyWZb2oA0+aCbEBxG7vxLK+6B/ FE1khUthOTAeH2QHEtQOERPIe/Lo+CNcd3Tw3KxMyuC9wzoAsT4Ef76p7 Q==; X-IronPort-AV: E=Sophos;i="5.97,304,1669100400"; d="scan'208";a="137771389" Received: from unknown (HELO email.microchip.com) ([170.129.1.10]) by esa6.microchip.iphmx.com with ESMTP/TLS/AES256-SHA256; 17 Feb 2023 05:42:03 -0700 Received: from chn-vm-ex01.mchp-main.com (10.10.85.143) by chn-vm-ex04.mchp-main.com (10.10.85.152) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2507.16; Fri, 17 Feb 2023 05:42:03 -0700 Received: from m18063-ThinkPad-T460p.mchp-main.com (10.10.115.15) by chn-vm-ex01.mchp-main.com (10.10.85.143) with Microsoft SMTP Server id 15.1.2507.16 via Frontend Transport; Fri, 17 Feb 2023 05:42:00 -0700 From: Claudiu Beznea To: , , , , , , , CC: , , , , Claudiu Beznea Subject: [PATCH v2 0/3] ASoC: mchp-pdmc: fix poc noises when starting capture Date: Fri, 17 Feb 2023 14:41:48 +0200 Message-ID: <20230217124151.236216-1-claudiu.beznea@microchip.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 X-Spam-Status: No, score=-4.4 required=5.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_MED, RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: devicetree@vger.kernel.org To start capture on Microchip PDMC the enable bits for each supported microphone need to be set. After this bit is set the PDMC starts to receive data from microphones and it considers this data as valid data. Thus if microphones are not ready the PDMC captures anyway data from its lines. This data is interpreted by the human ear as poc noises. To avoid this the following software workaround need to be applied when starting capture: 1/ enable PDMC channel 2/ wait 150ms 3/ execute 16 dummy reads from RHR 4/ clear interrupts 5/ enable interrupts 6/ enable DMA channel For this workaround to work step 6 need to be executed at the end. For step 6 was added patch 1/3 from this series. With this, component DAI driver sets its struct snd_soc_component_driver::start_dma_last = 1 and proper action is taken based on this flag when starting DAI trigger vs DMA. Thank you, Claudiu Beznea Changes in v2: - patch 1/3 from v1 is now "ASoC: soc-pcm: add option to start DMA after DAI" - pass start_dma_last from component DAI driver object (struct snd_soc_component_driver::start_dma_last); adapt patch 3/3 after this; - in patch 1/3 s/Do we need to start dma first/Do we need to start dma last in comment from soc_pcm_trigger() - collect review tag from Krzysztof Claudiu Beznea (3): ASoC: soc-pcm: add option to start DMA after DAI ASoC: dt-bindings: sama7g5-pdmc: add microchip,startup-delay-us binding ASoC: mchp-pdmc: fix poc noise at capture startup .../sound/microchip,sama7g5-pdmc.yaml | 6 ++ include/sound/soc-component.h | 2 + sound/soc/atmel/mchp-pdmc.c | 55 +++++++++++++++++-- sound/soc/soc-pcm.c | 27 +++++++-- 4 files changed, 80 insertions(+), 10 deletions(-)