Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756935AbaDWOFI (ORCPT ); Wed, 23 Apr 2014 10:05:08 -0400 Received: from mail-ob0-f179.google.com ([209.85.214.179]:63432 "EHLO mail-ob0-f179.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756215AbaDWOFE convert rfc822-to-8bit (ORCPT ); Wed, 23 Apr 2014 10:05:04 -0400 MIME-Version: 1.0 In-Reply-To: <20140422155602.GA19762@kwain> References: <1397135274-10764-1-git-send-email-antoine.tenart@free-electrons.com> <1397135274-10764-3-git-send-email-antoine.tenart@free-electrons.com> <5347AFF4.3050607@gmail.com> <20140411123737.GA5903@kwain> <5347EF8A.8040600@gmail.com> <20140422155602.GA19762@kwain> Date: Wed, 23 Apr 2014 16:05:03 +0200 Message-ID: Subject: Re: [PATCH RESEND 2/5] pinctrl: berlin: add a pinctrl driver for Marvell Berlin SoCs From: Linus Walleij To: =?UTF-8?Q?Antoine_T=C3=A9nart?= Cc: Sebastian Hesselbarth , Alexandre Belloni , zmxu@marvell.com, Jisheng Zhang , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , "linux-kernel@vger.kernel.org" Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Apr 22, 2014 at 5:56 PM, Antoine Ténart wrote: > On Tue, Apr 22, 2014 at 02:52:10PM +0200, Linus Walleij wrote: >> On Fri, Apr 11, 2014 at 3:35 PM, Sebastian Hesselbarth >> wrote: >> > On 04/11/2014 02:37 PM, Antoine Ténart wrote: >> >> On Fri, Apr 11, 2014 at 11:03:48AM +0200, Sebastian Hesselbarth wrote: >> >>> On 04/10/2014 03:07 PM, Antoine Ténart wrote: >> >> >>> Having said that, the above assumes that each function is unique >> >>> but IIRC the idea of the function table was to group pins/groups >> >>> with the same function, e.g. function "gpio", groups 1,7,25,... >> >> >> >> Most of the functions you can use on the Berlin they will be unique and >> >> would >> >> only be used in one group, except for the 'gpio' one. >> > >> > Yeah, I had a similar discussion about it back then for mvebu. IIRC, the >> > correct answer is: Have a list of functions with groups assigned to it >> > no matter if there is only one group per function (or 40 per function as >> > it will be for gpio). >> > >> > Maybe Linus can give an update on how to deal with it? >> >> Have you considered implementing pinmux_ops >> .gpio_request_enable(), .gpio_set_direction() and >> .gpio_disable_free() instead of defining groups for each >> and every GPIO? > > The function 'gpio' can be found on different groups. But the Berlin pin muxing > does not allow to configure a pin individually. It is then not possible to mux > GPIO pins individually. For example the 'gpio' function of group 'GSM2' on the > BG2Q will mux GPIOs 17 *and* 18. > > Groups does not have more than a single 'gpio' function. > > Since the gpio_request_enable() comment says 'Implement this only if you can mux > every pin individually as GPIO', I did not considered implementing these > functions. OK makes perfect sense. Then I guess the current implementation is the best alternative, but I may need to look closer. Yours, Linus Walleij -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/