From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Ruehl Subject: Re: spi-imx: add support for single burst mode (8,16,32) Date: Wed, 1 Jun 2016 14:39:35 +0800 Message-ID: <574E8327.80606@gtsys.com.hk> References: <574D5C2B.1000400@gtsys.com.hk> <20160531110608.GG31666@pengutronix.de> <574E405F.9090000@gtsys.com.hk> <20160601063029.GB11074@pengutronix.de> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: Fabio Estevam , Anton Bondarenko , Mark Brown , Sascha Hauer , "linux-spi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" To: Sascha Hauer Return-path: In-Reply-To: <20160601063029.GB11074-bIcnvbaLZ9MEGnE8C9+IrQ@public.gmane.org> Sender: linux-spi-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-ID: On Wednesday, June 01, 2016 02:30 PM, Sascha Hauer wrote: > On Wed, Jun 01, 2016 at 09:54:39AM +0800, Chris Ruehl wrote: >> On Tuesday, May 31, 2016 07:06 PM, Sascha Hauer wrote: >>> On Tue, May 31, 2016 at 07:43:37AM -0300, Fabio Estevam wrote: >>>> [Adding Sascha and Anton in Cc] >>>> >>>> On Tue, May 31, 2016 at 6:40 AM, Chris Ruehl wrote: >>>>> Hi, >>>>> >>>>> as imx6 using multiple burst to send data to spi slaves and drop the >>>>> chipselect between the words by default my sensor NXP MPL115A1 wasn't >>>>> working. >>> >>> I generally recommend to use GPIO Chip selects. The SPI controller has >>> its own ideas when to assert the chipselects which is hard to match (if >>> possible at all) with what Linux SPI expects. See the cs-gpios device >>> tree property. >>> >>> Sascha >> >> Sascha that's a good approach to fight this problem, if you have the >> choice. Sadly my hardware design is finished and I can only switch to >> a gpio by run wires on the finished PCB.. and that's not what I want. > > I'm not suggesting to change your hardware. Every chipselect pin can be > configured as GPIO aswell, i.e. exchange > MX6QDL_PAD_DISP0_DAT3__ECSPI3_SS0 with MX6QDL_PAD_DISP0_DAT3__GPIO4_IO24 > and be done with it. > > Sascha > Hi Sascha, yes, :) agree. But my native chip select with single burst is doing the job flawless now. Chris -- To unsubscribe from this list: send the line "unsubscribe linux-spi" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html