From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?UTF-8?Q?Emmanuel_Fust=c3=a9?= Subject: Re: [PATCH 0/3] ASoC: Enable a new IC master mode: bcm2835<=>IC<=>cs42xx8 Date: Sun, 26 Feb 2017 23:49:49 +0100 Message-ID: <97c0ea59-edbd-ed59-eb4a-82019dae080c@laposte.net> References: <20170225133952.GA28091@camel2.lan> <8cf68a3e-330d-e76d-e276-5df5453e3baf@flatmax.org> <20170226144958.GA5543@camel2.lan> <141ed0ce-2801-1ace-84b5-c2881ad8921d@laposte.net> Reply-To: emmanuel.fuste@laposte.net Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252"; Format="flowed" Content-Transfer-Encoding: quoted-printable Return-path: Received: from smtp.laposte.net (smtpoutz25.laposte.net [194.117.213.100]) by alsa0.perex.cz (Postfix) with ESMTP id 9C533266A74 for ; Sun, 26 Feb 2017 23:49:49 +0100 (CET) Received: from smtp.laposte.net (localhost [127.0.0.1]) by lpn-prd-vrout013 (Postfix) with ESMTP id E0593104C4B for ; Sun, 26 Feb 2017 23:49:48 +0100 (CET) Received: from smtp.laposte.net (localhost [127.0.0.1]) by lpn-prd-vrout013 (Postfix) with ESMTP id D295F104C77 for ; Sun, 26 Feb 2017 23:49:48 +0100 (CET) Received: from lpn-prd-vrin003 (lpn-prd-vrin003.laposte [10.128.63.4]) by lpn-prd-vrout013 (Postfix) with ESMTP id CEA2B104C4B for ; Sun, 26 Feb 2017 23:49:48 +0100 (CET) Received: from lpn-prd-vrin003 (localhost [127.0.0.1]) by lpn-prd-vrin003 (Postfix) with ESMTP id BC90048EA14 for ; Sun, 26 Feb 2017 23:49:48 +0100 (CET) In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: alsa-devel-bounces@alsa-project.org Sender: alsa-devel-bounces@alsa-project.org To: Matt Flax Cc: alsa-devel@alsa-project.org, ckeepax@opensource.wolfsonmicro.com List-Id: alsa-devel@alsa-project.org Le 26/02/2017 =E0 22:44, Matt Flax a =E9crit : > > > On 27/02/17 07:41, Emmanuel Fust=E9 wrote: >> >> >> I'm a complete newbie to ASoC but I take part to this tread to learn = >> as I hate to see how badly all diy and amateur audio hw are = >> integrated with Alsa/ASoC/Linux and so never go upstream. On a = >> professional/commercial dev, you would never take this ... convoluted = >> I2S multi channel path. >> > > Hey Emmanuel, > > We now know that we can retrofit legacy I2S silicon for multichannel, = > in a very direct manner. > > If you were a chip manufacturer and you could potentially increase = > your market take up by hundreds of millions of new potential low power = > devices, wouldn't you manufacture ALL new chips with these minor = > modifications ? > > Matt Hi, No, because this is a hack. There is established an more importantly = interoperable bus standards to do multichannel digital audio : TDM/DSP = A/DSP B As today standards, even ultra low power and low powerfull IC are able = to do standard multichannel serial audio. Atmel AT & ARM cortex M =B5C, = STMicro STM32 family etc ... I2S signaling is only part of the equation, fifo, DMA handling, etc... = of the multichannel part could be important depending of the implementation. And the FPGA glue logic is way more costly than choosing a SOC / =B5C with = a properly designed multichannel serial audio IP. The real question is why this SOC so poorly endowed with bad device IP = is so popular... but this is another story... Don't get me wrong. I'm nevertheless a real supporter of this "hack". = But it should be done the "right" way. Emmanuel.