From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan =?ISO-8859-1?Q?L=FCbbe?= Subject: Re: [PATCH v2 5/5] i2c: davinci: use ICPFUNC to toggle I2C as gpio for bus recovery Date: Tue, 07 Jul 2015 15:37:49 +0200 Message-ID: <1436276269.3344.94.camel@pengutronix.de> References: <1417010393-30598-1-git-send-email-grygorii.strashko@ti.com> <1417010393-30598-6-git-send-email-grygorii.strashko@ti.com> <20141126160407.GN4431@pengutronix.de> <5476085B.40009@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: <5476085B.40009-l0cyMroinI0@public.gmane.org> Sender: linux-i2c-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Grygorii Strashko Cc: Uwe =?ISO-8859-1?Q?Kleine-K=F6nig?= , Wolfram Sang , Sekhar Nori , linux-i2c-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-arm-kernel-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Mike Looijmans , Kevin Hilman , Santosh Shilimkar , Murali Karicheri , devicetree-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: devicetree@vger.kernel.org On Mi, 2014-11-26 at 19:05 +0200, Grygorii Strashko wrote: > On 11/26/2014 06:04 PM, Uwe Kleine-K=C3=B6nig wrote: > > On Wed, Nov 26, 2014 at 03:59:53PM +0200, Grygorii Strashko wrote: > >> Having a board where the I2C bus locks up occasionally made it cle= ar > >> that the bus recovery in the i2c-davinci driver will only work on > >> some boards, because on regular boards, this will only toggle GPIO > >> lines that aren't muxed to the actual pins. > >> > >> The I2C controller on SoCs like da850 (and da830), Keystone 2 has = the > >> built-in capability to bit-bang its lines by using the ICPFUNC reg= isters > >> of the i2c controller. > >> Implement the suggested procedure by toggling SCL and checking SDA= using > >> the ICPFUNC registers of the I2C controller when present. Allow pl= atforms > >> to indicate the presence of the ICPFUNC registers with a has_pfunc= platform > >> data flag and add optional DT property "ti,has-pfunc" to indicate > >> the same in DT. > > On what does it depend if this pfunc stuff works or not? Only the S= oC, > > or also on some board specific properties? >=20 > SoC / set of SoCs. Also, similar feature is supported by OMAP and AM3= 35x/AM437x SoCs > using I2C_SYSTEST register. >=20 > > Given the former using the > > compatible string to detect its availability would be better. (In t= his > > case also sorry, didn't consider this case when requesting the prop= erty > > in the last round.) I only stumbled across this after it was merged, with the additional ti,has-pfunc property instead of using the compatible string (which would be better for a soc-dependent feature). Can we still fix this? Regards, Jan --=20 Pengutronix e.K. | = | Industrial Linux Solutions | http://www.pengutronix.de/= | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 = | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-555= 5 |