From patchwork Tue Jul 6 08:39:04 2010 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Raffaele Recalcati X-Patchwork-Id: 110560 Received: from devils.ext.ti.com (devils.ext.ti.com [198.47.26.153]) by demeter.kernel.org (8.14.4/8.14.3) with ESMTP id o66NFhPm024023 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK) for ; Tue, 6 Jul 2010 23:16:46 GMT Received: from dlep33.itg.ti.com ([157.170.170.112]) by devils.ext.ti.com (8.13.7/8.13.7) with ESMTP id o66NDZL4008685 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 6 Jul 2010 18:13:35 -0500 Received: from linux.omap.com (localhost [127.0.0.1]) by dlep33.itg.ti.com (8.13.7/8.13.7) with ESMTP id o66NDYAg026454; Tue, 6 Jul 2010 18:13:34 -0500 (CDT) Received: from linux.omap.com (localhost [127.0.0.1]) by linux.omap.com (Postfix) with ESMTP id AB9D78062D; Tue, 6 Jul 2010 18:13:34 -0500 (CDT) X-Original-To: davinci-linux-open-source@linux.davincidsp.com Delivered-To: davinci-linux-open-source@linux.davincidsp.com Received: from dflp52.itg.ti.com (dflp52.itg.ti.com [128.247.22.96]) by linux.omap.com (Postfix) with ESMTP id 024C880626 for ; 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c=nofws; d=gmail.com; s=gamma; h=from:to:cc:subject:date:message-id:x-mailer:in-reply-to:references; b=ZAgN3f0EDikzAeQVxhoTu+XUIRXj3OVSRCzqRxRGtPnR2WYuC4Tp8qYupO3lkD3VMy F8eWSl3KSKCUXHjVVTHJX3a5Cev9fK+oUISzKJwUnYpDL1rVD/izb/wFJf7RaeK4Um7O 3RcFmm8VYkBJO8ArmbgHg5xsOtuMHfLtlkDZg= Received: by 10.86.89.8 with SMTP id m8mr3136750fgb.64.1278405545226; Tue, 06 Jul 2010 01:39:05 -0700 (PDT) Received: from localhost.localdomain (host81-90-static.72-81-b.business.telecomitalia.it [81.72.90.81]) by mx.google.com with ESMTPS id z16sm11251219fan.24.2010.07.06.01.39.02 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 06 Jul 2010 01:39:04 -0700 (PDT) From: Raffaele Recalcati To: davinci-linux-open-source@linux.davincidsp.com Subject: [PATCH 3/3] ASoC: DaVinci: More accurate continuous serial clock for McBSP (I2S) Date: Tue, 6 Jul 2010 10:39:04 +0200 Message-Id: <1278405544-3852-4-git-send-email-lamiaposta71@gmail.com> X-Mailer: git-send-email 1.7.0.4 In-Reply-To: <1278405544-3852-1-git-send-email-lamiaposta71@gmail.com> References: <1278405544-3852-1-git-send-email-lamiaposta71@gmail.com> X-pstn-neptune: 0/0/0.00/0 X-pstn-levels: (S:23.93426/99.90000 CV:99.9000 FC:95.5390 LC:95.5390 R:95.9108 P:95.9108 M:97.0282 C:98.6951 ) X-pstn-settings: 2 (0.5000:0.5000) s cv gt3 gt2 gt1 r p m c X-pstn-addresses: from [db-null] X-Mailman-Approved-At: Tue, 06 Jul 2010 18:07:30 -0500 Cc: alsa-devel@alsa-project.org, Russell King , Takashi Iwai , Mark Brown , linux-kernel@vger.kernel.org, Raffaele Recalcati , Jaroslav Kysela , linux-arm-kernel@lists.infradead.org, Liam Girdwood X-BeenThere: davinci-linux-open-source@linux.davincidsp.com X-Mailman-Version: 2.1.12 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , MIME-Version: 1.0 Sender: davinci-linux-open-source-bounces@linux.davincidsp.com Errors-To: davinci-linux-open-source-bounces@linux.davincidsp.com X-Greylist: Sender succeeded STARTTLS authentication, not delayed by milter-greylist-4.2.3 (demeter.kernel.org [140.211.167.41]); Tue, 06 Jul 2010 23:16:46 +0000 (UTC) diff --git a/arch/arm/mach-davinci/include/mach/asp.h b/arch/arm/mach-davinci/include/mach/asp.h index 0847d21..b12c69e 100644 --- a/arch/arm/mach-davinci/include/mach/asp.h +++ b/arch/arm/mach-davinci/include/mach/asp.h @@ -73,6 +73,39 @@ struct snd_platform_data { */ int clk_input_pin; + /* + * This flag works when both clock and FS are outputs for the cpu + * and makes clock more accurate (FS is not symmetrical and the + * clock is very fast. + * The clock becoming faster is named + * i2s continuous serial clock (I2S_SCK) and it is an externally + * visible bit clock. + * + * first line : WordSelect + * second line : ContinuousSerialClock + * third line: SerialData + * + * SYMMETRICAL APPROACH: + * _______________________ LEFT + * _| RIGHT |______________________| + * _ _ _ _ _ _ _ _ + * _| |_| |_ x16 _| |_| |_| |_| |_ x16 _| |_| |_ + * _ _ _ _ _ _ _ _ + * _/ \_/ \_ ... _/ \_/ \_/ \_/ \_ ... _/ \_/ \_ + * \_/ \_/ \_/ \_/ \_/ \_/ \_/ \_/ + * + * ACCURATE CLOCK APPROACH: + * ______________ LEFT + * _| RIGHT |_______________________________| + * _ _ _ _ _ _ _ _ _ + * _| |_ x16 _| |_| |_ x16 _| |_| |_| |_| |_| |_| | + * _ _ _ _ dummy cycles + * _/ \_ ... _/ \_/ \_ ... _/ \__________________ + * \_/ \_/ \_/ \_/ + * + */ + bool i2s_accurate_sck; + /* McASP specific fields */ int tdm_slots; u8 op_mode; diff --git a/sound/soc/davinci/davinci-i2s.c b/sound/soc/davinci/davinci-i2s.c index ba5644b..b251bc9 100644 --- a/sound/soc/davinci/davinci-i2s.c +++ b/sound/soc/davinci/davinci-i2s.c @@ -155,6 +155,7 @@ struct davinci_mcbsp_dev { unsigned int fmt; int clk_div; int clk_input_pin; + bool i2s_accurate_sck; }; static inline void davinci_mcbsp_write_reg(struct davinci_mcbsp_dev *dev, @@ -447,11 +448,23 @@ static int davinci_i2s_hw_params(struct snd_pcm_substream *substream, DAVINCI_MCBSP_SRGR_CLKSM; srgr |= DAVINCI_MCBSP_SRGR_FWID(mcbsp_word_length * 8 - 1); - /* symmetric waveforms */ - clk_div = freq / (mcbsp_word_length * 16) / - params->rate_num * params->rate_den; - srgr |= DAVINCI_MCBSP_SRGR_FPER(mcbsp_word_length * - 16 - 1); + if (dev->i2s_accurate_sck) { + clk_div = 256; + do { + framesize = (freq / (--clk_div)) / + params->rate_num * + params->rate_den; + } while (((framesize < 33) || (framesize > 4095)) && + (clk_div)); + clk_div--; + srgr |= DAVINCI_MCBSP_SRGR_FPER(framesize - 1); + } else { + /* symmetric waveforms */ + clk_div = freq / (mcbsp_word_length * 16) / + params->rate_num * params->rate_den; + srgr |= DAVINCI_MCBSP_SRGR_FPER(mcbsp_word_length * + 16 - 1); + } clk_div &= 0xFF; srgr |= clk_div; break; @@ -662,6 +675,7 @@ static int davinci_i2s_probe(struct platform_device *pdev) dev->dma_params[SNDRV_PCM_STREAM_CAPTURE].sram_size = pdata->sram_size_capture; dev->clk_input_pin = pdata->clk_input_pin; + dev->i2s_accurate_sck = pdata->i2s_accurate_sck; } dev->clk = clk_get(&pdev->dev, NULL); if (IS_ERR(dev->clk)) {