From mboxrd@z Thu Jan 1 00:00:00 1970 From: Fabio Estevam Subject: Re: [PATCH] i2c: i2c_mxs: Set ACK_MODE bit Date: Mon, 19 Aug 2013 09:19:01 -0300 Message-ID: <52120D35.707@freescale.com> References: <1372780860-12972-1-git-send-email-fabio.estevam@freescale.com> <20130815100809.GE2987@katana> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130815100809.GE2987@katana> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wolfram Sang Cc: marex-ynQEQJNshbs@public.gmane.org, shawn.guo-QSEj5FYQhm4dnm+yROfE0A@public.gmane.org, kernel-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org, festevam-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org, linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, alexandre.belloni-wi1+55ScJUtKEb57/3fJTNBPR1lH4CV8@public.gmane.org, cb-/RsSufbtIHM@public.gmane.org List-Id: linux-i2c@vger.kernel.org On 08/15/2013 07:08 AM, Wolfram Sang wrote: > On Tue, Jul 02, 2013 at 01:01:00PM -0300, Fabio Estevam wrote: >> According to mx23 erratum 2727: >> >> "2727 : I2C 9th Clock Pulse (ACK) not generated when RETAIN_CLOCK set. >> >> Description: >> >> When RETAIN_CLOCK is set, the ninth clock pulse (ACK) is not generated. >> However, the SDA line is read at the proper timing interval. If >> RETAIN_CLOCK is cleared, the ninth clock pulse is generated. >> Also, the HW_I2C_VERSION register incorrectly states the version is 1.2. >> It should be 1.3. >> >> Workaround: >> HW_I2C_CTRL1[ACK_MODE] has default value of 0. It should be set to 1 to >> enable the fix for this issue." >> >> It has also been noticed that mx28 needs to implement this fix in order to have >> SMBus to work properly. >> >> Reported-by: Christoph Baumann >> Signed-off-by: Fabio Estevam > > What's with this one? Bogus? Needed? Still needed after PIO rework? According to the mx23 erratum 2727 this patch is needed. Regards, Fabio Estevam