From mboxrd@z Thu Jan 1 00:00:00 1970 From: John Hsu Subject: Re: [PATCH] ASoC: nau8810: Add driver for Nuvoton codec chip NAU88C10 Date: Mon, 8 Aug 2016 10:27:38 +0800 Message-ID: <57A7EE1A.1040307@nuvoton.com> References: <1466152834-29615-1-git-send-email-KCHSU0@nuvoton.com> <20160627171546.GE17217@sirena.org.uk> <5775E4C7.5010303@nuvoton.com> <20160701100423.GM6247@sirena.org.uk> <5779D93B.80106@nuvoton.com> <20160805120804.GV10383@sirena.org.uk> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; Format="flowed" Content-Transfer-Encoding: 7bit Return-path: Received: from maillog.nuvoton.com (maillog.nuvoton.com [202.39.227.15]) by alsa0.perex.cz (Postfix) with ESMTP id C5646265DFF for ; Mon, 8 Aug 2016 04:27:42 +0200 (CEST) In-Reply-To: <20160805120804.GV10383@sirena.org.uk> 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: Mark Brown Cc: YHCHuang@nuvoton.com, alsa-devel@alsa-project.org, CTLIN0@nuvoton.com, lgirdwood@gmail.com List-Id: alsa-devel@alsa-project.org Hi On 8/5/2016 8:08 PM, Mark Brown wrote: > On Mon, Jul 04, 2016 at 11:34:19AM +0800, John Hsu wrote: > >> On 7/1/2016 6:04 PM, Mark Brown wrote: >> > > >>> No, you don't - this is entirely normal for 7x9 regmaps, I've never seen >>> such a device that supported readback. Look at devices like wm8731 for >>> examples. >>> > > >> Sometimes, we need to know the codec information and need read it >> from hardware, not cache. I'm afraid that it can't be done in this >> case. >> > > What does the read actually look like on this device? > The data read from codec by the IIC bus is as the following. 0 0 0 0 0 0 0 D8 ACK D7 D6 D5 D4 D3 D2 D1 D0 The bottom 9 bits are the real register value. The nau8810_reg_read in driver is made by the formate.