From mboxrd@z Thu Jan 1 00:00:00 1970 From: Linus Walleij Subject: Re: [PATCH 3/4] ARM: pinctrl: Add Broadcom Capri pinctrl driver Date: Mon, 4 Nov 2013 13:24:10 +0100 Message-ID: References: <1380846199-12829-1-git-send-email-syin@broadcom.com> <1380846199-12829-4-git-send-email-syin@broadcom.com> <051069C10411E24D9749790C498526FA1BE027EA@SJEXCHMB12.corp.ad.broadcom.com> <051069C10411E24D9749790C498526FA1BE03D43@SJEXCHMB12.corp.ad.broadcom.com> <051069C10411E24D9749790C498526FA1BE0841D@SJEXCHMB12.corp.ad.broadcom.com> <051069C10411E24D9749790C498526FA1BE0B7D7@SJEXCHMB12.corp.ad.broadcom.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Return-path: In-Reply-To: <051069C10411E24D9749790C498526FA1BE0B7D7@SJEXCHMB12.corp.ad.broadcom.com> Sender: linux-doc-owner@vger.kernel.org To: Sherman Yin , =?ISO-8859-1?Q?Heiko_St=FCbner?= , Laxman Dewangan Cc: Mark Rutland , "devicetree@vger.kernel.org" , Christian Daudt , Russell King , Pawel Moll , Ian Campbell , Stephen Warren , "linux-doc@vger.kernel.org" , "linux-kernel@vger.kernel.org" , Rob Herring , bcm-kernel-feedback-list , Rob Landley , Grant Likely , Matt Porter , "linux-arm-kernel@lists.infradead.org" List-Id: devicetree@vger.kernel.org On Sat, Oct 26, 2013 at 12:48 AM, Sherman Yin wrote: > So I will go ahead and make the change in pinconf-generic.c and pinctrl-bindings.txt > to include parsing of the "slew-rate" property and submit it as part of my pinctrl > changes. OK, good. > Question regarding pinctrl-generic: in pinctrl-bindings.txt, this is said about the > "function" property: > > 169- function takes a list of function names/IDs as a required argument. The > 170 specific binding for the hardware defines: > 171 - Whether the entries are integers or strings, and their meaning. > 172 - Whether only a single entry is allowed (which is applied to all entries > 173 in the pins property), or whether there may alternatively be one entry per > 174 entry in the pins property, in which case the list lengths must match, and > 175 for each list index i, the function at list index i is applied to the pin > 176 at list index i. > > (Although it looks like pinconf_generic_dt_subnode_to_map() does not support > the "one entry per pin feature" for the "function" property yet.) > > In my driver, I have the "one entry per pin" support for all my properties instead > of just the function property, like the "drive_str" property below: > > + grp_1 { > + brcm,pins = "pin1", "pin2", "pin3"; > + brcm,function = "alt1", "alt2", "alt1"; > + brcm,drive_str = <2 4 6>; > + brcm,slew = <1>; > + }; OK. > I thought that would be convenient and allow users to group pins together based > on functionality and without the restriction that the pins must have the same > properties. Do you think that's a good idea and are there plans to support that in > the generic pinconfig? If so, I can look into porting my implementation to > pinconf-generic.c - but first I have to figure out how some of the properties would > work if more than one value could be specified (eg. "bias-disable" which takes no > values) Hm I don't quite get it I think. It depends on the old bindings still working and full compatibility with old device trees. It might be a bit confusing. I need help from Heiko on this I think. Yours, Linus Walleij