From patchwork Tue Jun 5 11:01:32 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shreyas NC X-Patchwork-Id: 10448041 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 4C2D26024A for ; Tue, 5 Jun 2018 11:03:37 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 38D2928892 for ; Tue, 5 Jun 2018 11:03:37 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 2D95928944; Tue, 5 Jun 2018 11:03:37 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.9 required=2.0 tests=BAYES_00, MAILING_LIST_MULTI, RCVD_IN_DNSWL_NONE autolearn=ham version=3.3.1 Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D98428892 for ; Tue, 5 Jun 2018 11:03:36 +0000 (UTC) Received: from alsa0.perex.cz (localhost [127.0.0.1]) by alsa0.perex.cz (Postfix) with ESMTP id AE90F267ACB; Tue, 5 Jun 2018 13:03:27 +0200 (CEST) X-Original-To: alsa-devel@alsa-project.org Delivered-To: alsa-devel@alsa-project.org Received: by alsa0.perex.cz (Postfix, from userid 1000) id 5B1B0267A6C; Tue, 5 Jun 2018 13:03:24 +0200 (CEST) Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by alsa0.perex.cz (Postfix) with ESMTP id C05A9267A6B for ; Tue, 5 Jun 2018 13:03:21 +0200 (CEST) X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga101.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 05 Jun 2018 04:03:20 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.49,478,1520924400"; d="scan'208";a="45385383" Received: from snc-desk.iind.intel.com ([10.223.96.118]) by fmsmga008.fm.intel.com with ESMTP; 05 Jun 2018 04:03:18 -0700 From: Shreyas NC To: alsa-devel@alsa-project.org Date: Tue, 5 Jun 2018 16:31:32 +0530 Message-Id: <1528196497-29554-2-git-send-email-shreyas.nc@intel.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1528196497-29554-1-git-send-email-shreyas.nc@intel.com> References: <1528196497-29554-1-git-send-email-shreyas.nc@intel.com> Cc: patches.audio@intel.com, gregkh@linuxfoundation.org, pierre-louis.bossart@linux.intel.com, vkoul@kernel.org, Shreyas NC , sanyog.r.kale@intel.com Subject: [alsa-devel] [PATCH 1/6] Documentation: soundwire: Add documentation for Multi link X-BeenThere: alsa-devel@alsa-project.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: "Alsa-devel mailing list for ALSA developers - http://www.alsa-project.org" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org X-Virus-Scanned: ClamAV using ClamSMTP From: Sanyog Kale Add example and documentation to describe Multi Link streams Signed-off-by: Pierre-Louis Bossart Signed-off-by: Sanyog Kale Signed-off-by: Vinod Koul Signed-off-by: Shreyas NC --- Documentation/driver-api/soundwire/stream.rst | 30 ++++++++++++++++++++++++++- 1 file changed, 29 insertions(+), 1 deletion(-) diff --git a/Documentation/driver-api/soundwire/stream.rst b/Documentation/driver-api/soundwire/stream.rst index 29121aa..af9529b 100644 --- a/Documentation/driver-api/soundwire/stream.rst +++ b/Documentation/driver-api/soundwire/stream.rst @@ -76,7 +76,35 @@ Slaves are using single port. :: +---------------+ -Example 4: Stereo Stream with L and R channel is rendered by two different +Example 4: Stereo Stream with L and R channel is rendered by 2 Masters, each +rendering one channel, and is received by two different Slaves, each +receiving one channel. Both Masters and both Slaves are using single port. :: + + +---------------+ Clock Signal +---------------+ + | Master +----------------------------------+ Slave | + | Interface | | Interface | + | 1 | | 1 | + | | Data Signal | | + | L +----------------------------------+ L | + | (Data) | Data Direction | (Data) | + +---------------+ +-----------------------> +---------------+ + + +---------------+ Clock Signal +---------------+ + | Master +----------------------------------+ Slave | + | Interface | | Interface | + | 2 | | 2 | + | | Data Signal | | + | R +----------------------------------+ R | + | (Data) | Data Direction | (Data) | + +---------------+ +-----------------------> +---------------+ + +Note: In multi-link cases like above, to lock, one would acquire a global +lock and then go on locking bus instances. But, in this case the caller +framework(ASoC DPCM) guarantees that stream operations on a card are +always serialized. So, there is no race condition and hence no need for +global lock. + +Example 5: Stereo Stream with L and R channel is rendered by two different Ports of the Master and is received by only single Port of the Slave interface. ::