From patchwork Thu Aug 28 06:52:40 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Horman X-Patchwork-Id: 4802901 Return-Path: X-Original-To: patchwork-ltsi-dev@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 91A229F375 for ; Thu, 28 Aug 2014 09:14:37 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id BE40F20123 for ; Thu, 28 Aug 2014 09:14:36 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (using TLSv1.2 with cipher DHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EA34E200DF for ; Thu, 28 Aug 2014 09:14:35 +0000 (UTC) Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 6A2F01770; Thu, 28 Aug 2014 07:41:37 +0000 (UTC) X-Original-To: ltsi-dev@lists.linuxfoundation.org Delivered-To: ltsi-dev@mail.linuxfoundation.org Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 83507177A for ; Thu, 28 Aug 2014 07:39:07 +0000 (UTC) X-Greylist: from auto-whitelisted by SQLgrey-1.7.6 Received: from kirsty.vergenet.net (kirsty.vergenet.net [202.4.237.240]) by smtp1.linuxfoundation.org (Postfix) with ESMTP id 14DFA20224 for ; Thu, 28 Aug 2014 07:39:07 +0000 (UTC) Received: from ayumi.isobedori.kobe.vergenet.net (p4222-ipbfp1605kobeminato.hyogo.ocn.ne.jp [114.154.95.222]) by kirsty.vergenet.net (Postfix) with ESMTP id 12F9A267162; Thu, 28 Aug 2014 17:07:33 +1000 (EST) Received: by ayumi.isobedori.kobe.vergenet.net (Postfix, from userid 7100) id 7A679EDE8E4; Thu, 28 Aug 2014 16:07:31 +0900 (JST) From: Simon Horman To: ltsi-dev@lists.linuxfoundation.org Date: Thu, 28 Aug 2014 15:52:40 +0900 Message-Id: <1409209620-24487-35-git-send-email-horms+renesas@verge.net.au> X-Mailer: git-send-email 2.0.1 In-Reply-To: <1409209620-24487-1-git-send-email-horms+renesas@verge.net.au> References: <1409209620-24487-1-git-send-email-horms+renesas@verge.net.au> X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org Cc: Magnus Damm Subject: [LTSI-dev] [PATCH LTSI-3.14 034/894] ASoC: rsnd: explain SRC bypass mode settings in comment X-BeenThere: ltsi-dev@lists.linuxfoundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: "A list to discuss patches, development, and other things related to the LTSI project" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: ltsi-dev-bounces@lists.linuxfoundation.org Errors-To: ltsi-dev-bounces@lists.linuxfoundation.org X-Virus-Scanned: ClamAV using ClamSMTP From: Kuninori Morimoto SRC bypass mode is useful for debugging. This patch explains SRC bypass mode settings in comment Signed-off-by: Kuninori Morimoto Signed-off-by: Mark Brown (cherry picked from commit 41c6221c39accdc4fe2b0c0fa196b6302b704e57) Signed-off-by: Simon Horman --- sound/soc/sh/rcar/scu.c | 45 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 45 insertions(+) diff --git a/sound/soc/sh/rcar/scu.c b/sound/soc/sh/rcar/scu.c index 872a115..076aa71 100644 --- a/sound/soc/sh/rcar/scu.c +++ b/sound/soc/sh/rcar/scu.c @@ -40,6 +40,51 @@ struct rsnd_scu { * */ +/* + * How to use SRC bypass mode for debugging + * + * SRC has bypass mode, and it is useful for debugging. + * In Gen2 case, + * SRCm_MODE controls whether SRC is used or not + * SSI_MODE0 controls whether SSIU which receives SRC data + * is used or not. + * Both SRCm_MODE/SSI_MODE0 settings are needed if you use SRC, + * but SRC bypass mode needs SSI_MODE0 only. + * + * This driver request + * struct rsnd_scu_platform_info { + * u32 flags; + * u32 convert_rate; + * } + * + * rsnd_scu_hpbif_is_enable() will be true + * if flags had RSND_SCU_USE_HPBIF, + * and it controls whether SSIU is used or not. + * + * rsnd_scu_convert_rate() indicates + * above convert_rate, and it controls + * whether SRC is used or not. + * + * ex) doesn't use SRC + * struct rsnd_scu_platform_info info = { + * .flags = 0, + * .convert_rate = 0, + * }; + * + * ex) uses SRC + * struct rsnd_scu_platform_info info = { + * .flags = RSND_SCU_USE_HPBIF, + * .convert_rate = 48000, + * }; + * + * ex) uses SRC bypass mode + * struct rsnd_scu_platform_info info = { + * .flags = RSND_SCU_USE_HPBIF, + * .convert_rate = 0, + * }; + * + */ + #define rsnd_mod_to_scu(_mod) \ container_of((_mod), struct rsnd_scu, mod)