From patchwork Fri Dec 5 12:37:09 2014 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mike Looijmans X-Patchwork-Id: 5443581 Return-Path: X-Original-To: patchwork-alsa-devel@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 606C69F1C5 for ; Fri, 5 Dec 2014 12:37:45 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 6149A2024D for ; Fri, 5 Dec 2014 12:37:44 +0000 (UTC) Received: from alsa0.perex.cz (alsa0.perex.cz [77.48.224.243]) by mail.kernel.org (Postfix) with ESMTP id CA426201BC for ; Fri, 5 Dec 2014 12:37:42 +0000 (UTC) Received: by alsa0.perex.cz (Postfix, from userid 1000) id 575BC2605DE; Fri, 5 Dec 2014 13:37:41 +0100 (CET) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Spam-Level: X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 Received: from alsa0.perex.cz (localhost [IPv6:::1]) by alsa0.perex.cz (Postfix) with ESMTP id E2E192605AB; Fri, 5 Dec 2014 13:37:27 +0100 (CET) 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 65B8B2605B1; Fri, 5 Dec 2014 13:37:26 +0100 (CET) Received: from atl4mhob06.myregisteredsite.com (atl4mhob06.myregisteredsite.com [209.17.115.44]) by alsa0.perex.cz (Postfix) with ESMTP id E976626059C for ; Fri, 5 Dec 2014 13:37:17 +0100 (CET) Received: from mailpod.hostingplatform.com ([10.30.71.205]) by atl4mhob06.myregisteredsite.com (8.14.4/8.14.4) with ESMTP id sB5CbFHS009966 for ; Fri, 5 Dec 2014 07:37:15 -0500 Received: (qmail 21327 invoked by uid 0); 5 Dec 2014 12:37:15 -0000 X-TCPREMOTEIP: 88.159.208.100 X-Authenticated-UID: mike@milosoftware.com Received: from unknown (HELO paradigit.TOPIC.LOCAL) (mike@milosoftware.com@88.159.208.100) by 0 with ESMTPA; 5 Dec 2014 12:37:15 -0000 From: Mike Looijmans To: lars@metafoo.de Date: Fri, 5 Dec 2014 13:37:09 +0100 Message-Id: <1417783029-22492-1-git-send-email-mike.looijmans@topic.nl> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <54806D4E.8040504@topic.nl> References: <54806D4E.8040504@topic.nl> Cc: Mike Looijmans , alsa-devel@alsa-project.org, linux-kernel@vger.kernel.org Subject: [alsa-devel] [PATCH v2] sound/soc/adi/axi-spdif.c: Support programmable master clock 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 If the master clock supports programmable rates, program it to generate the desired frequency. Only apply constraints when the clock is fixed. This allows proper clock generation for both 44100 and 48000 Hz based sampling rates if the platform supports it. The clock frequency must be set before enabling it. Enabling the clock was done in "startup", but that occurs before "hw_params" where the rate is known. Enabling a programmable clock without first setting a valid frequency may harm the system. Move the clock start to the hw_params routine, and keep track of whether the clock has been started, because shutdown may be called without having called hw_params first. Starting the clock and enabling the SPDIF output AFTER programming the dividers is a more logical order anyway. To detect if the source clock is fixed, the driver calls clk_round_rate for two frequencies. If the results are equal, or if the call returns an error, the driver assumes the clock is fixed. Signed-off-by: Mike Looijmans --- v2: Fix fixed clock detection as discussed. sound/soc/adi/axi-spdif.c | 60 ++++++++++++++++++++++++++++----------------- 1 file changed, 38 insertions(+), 22 deletions(-) diff --git a/sound/soc/adi/axi-spdif.c b/sound/soc/adi/axi-spdif.c index 198e3a4..8fd43a7 100644 --- a/sound/soc/adi/axi-spdif.c +++ b/sound/soc/adi/axi-spdif.c @@ -4,7 +4,6 @@ * * Licensed under the GPL-2. */ - #include #include #include @@ -44,6 +43,8 @@ struct axi_spdif { struct snd_ratnum ratnum; struct snd_pcm_hw_constraint_ratnums rate_constraints; + + bool clk_ref_running; }; static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd, @@ -79,6 +80,7 @@ static int axi_spdif_hw_params(struct snd_pcm_substream *substream, struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai); unsigned int rate = params_rate(params); unsigned int clkdiv, stat; + int ret; switch (params_rate(params)) { case 32000: @@ -95,6 +97,9 @@ static int axi_spdif_hw_params(struct snd_pcm_substream *substream, break; } + /* Try to set the master clock */ + clk_set_rate(spdif->clk_ref, rate * 128); + clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref), rate * 64 * 2) - 1; clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET; @@ -103,6 +108,14 @@ static int axi_spdif_hw_params(struct snd_pcm_substream *substream, regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv); + ret = clk_prepare_enable(spdif->clk_ref); + if (ret) + return ret; + spdif->clk_ref_running = true; + + regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, + AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN); + return 0; } @@ -121,18 +134,13 @@ static int axi_spdif_startup(struct snd_pcm_substream *substream, struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai); int ret; - ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0, - SNDRV_PCM_HW_PARAM_RATE, - &spdif->rate_constraints); - if (ret) - return ret; - - ret = clk_prepare_enable(spdif->clk_ref); - if (ret) - return ret; - - regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, - AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN); + if (spdif->rate_constraints.nrats) { + ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0, + SNDRV_PCM_HW_PARAM_RATE, + &spdif->rate_constraints); + if (ret) + return ret; + } return 0; } @@ -145,7 +153,10 @@ static void axi_spdif_shutdown(struct snd_pcm_substream *substream, regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, AXI_SPDIF_CTRL_TXEN, 0); - clk_disable_unprepare(spdif->clk_ref); + if (spdif->clk_ref_running) { + clk_disable_unprepare(spdif->clk_ref); + spdif->clk_ref_running = false; + } } static const struct snd_soc_dai_ops axi_spdif_dai_ops = { @@ -183,6 +194,7 @@ static int axi_spdif_probe(struct platform_device *pdev) struct resource *res; void __iomem *base; int ret; + long rate; spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL); if (!spdif) @@ -216,14 +228,18 @@ static int axi_spdif_probe(struct platform_device *pdev) spdif->dma_data.addr_width = 4; spdif->dma_data.maxburst = 1; - spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128; - spdif->ratnum.den_step = 1; - spdif->ratnum.den_min = 1; - spdif->ratnum.den_max = 64; - - spdif->rate_constraints.rats = &spdif->ratnum; - spdif->rate_constraints.nrats = 1; - + /* Determine if the clock rate is fixed. If it cannot change frequency, + * it returns an error or it will simply return its fixed value. */ + rate = clk_round_rate(spdif->clk_ref, 128 * 44100); + if (rate < 0 || rate != clk_round_rate(spdif->clk_ref, 128 * 48000)) { + spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128; + spdif->ratnum.den_step = 1; + spdif->ratnum.den_min = 1; + spdif->ratnum.den_max = 64; + + spdif->rate_constraints.rats = &spdif->ratnum; + spdif->rate_constraints.nrats = 1; + } ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component, &axi_spdif_dai, 1); if (ret)