From mboxrd@z Thu Jan 1 00:00:00 1970 From: Nicolin Chen Subject: Re: [alsa-devel] [PATCH] ASoC: fsl: sai: Fix clock source for mclk0 Date: Sun, 21 Apr 2019 01:26:28 -0700 Message-ID: <20190421082627.GB8304@Asurada> References: <20190420154038.14576-1-daniel.baluta@nxp.com> <20190421053749.GA5552@Asurada> <20190421080439.GA8784@Asurada> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20190421080439.GA8784@Asurada> Sender: linux-kernel-owner@vger.kernel.org To: Daniel Baluta Cc: Daniel Baluta , "alsa-devel@alsa-project.org" , "timur@kernel.org" , "Xiubo.Lee@gmail.com" , "linuxppc-dev@lists.ozlabs.org" , "S.j. Wang" , "tiwai@suse.com" , "lgirdwood@gmail.com" , "broonie@kernel.org" , dl-linux-imx , "festevam@gmail.com" , "linux-kernel@vger.kernel.org" List-Id: alsa-devel@alsa-project.org On Sun, Apr 21, 2019 at 01:04:39AM -0700, Nicolin Chen wrote: > On Sun, Apr 21, 2019 at 10:26:40AM +0300, Daniel Baluta wrote: > > > Firstly, according to your commit message, neither imx8qm nor > > > imx6sx has an "mclk0" clock in the clock list. Either of them > > > starts with "mclk1". So, before you change the driver, I don't > > > think it's even a right thing to define an "mclk0" in the DT. > > > > From what I understand mclk0 means option 00b of MSEL bits which is: > > * busclk for i.MX8 > > * mclk1 for i.MX6/7. > > MSEL bit is used for an internal clock MUX to select four clock > inputs. However, these four clock inputs aren't exactly 1:1 of > SAI's inputs. As fas as I can tell, SAI only has one bus clock > and three MCLK[1-3]; the internal clock MUX maps the bus clock > or MCLK1 to its input0, and then linearly maps MCLK[1-3] to its > inputs[1-3]. So it doesn't sound right to me that you define an > "MCLK0" in the DT, as it's supposed to describe input clocks of > SAI block, other than its internal clock MUX's. Daniel, I think I's saying this too confident, though I do feel so :) But if you can prove me wrong and justify that there is an "MCLK0" as an external input of the SAI block, I will agree with this change. Thanks