Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751292AbaKFGHu (ORCPT ); Thu, 6 Nov 2014 01:07:50 -0500 Received: from mga11.intel.com ([192.55.52.93]:21436 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751195AbaKFGHt (ORCPT ); Thu, 6 Nov 2014 01:07:49 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.07,324,1413270000"; d="scan'208";a="627467238" Date: Thu, 6 Nov 2014 08:07:13 +0200 From: Mika Westerberg To: Olof Johansson Cc: Linus Walleij , Alexandre Courbot , Heikki Krogerus , Mathias Nyman , "Rafael J. Wysocki" , Ning Li , Alan Cox , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2 0/2] pinctrl: Intel Cherryview/Braswell support Message-ID: <20141106060713.GB1618@lahna.fi.intel.com> References: <1415012493-134561-1-git-send-email-mika.westerberg@linux.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Organization: Intel Finland Oy - BIC 0357606-4 - Westendinkatu 7, 02160 Espoo User-Agent: Mutt/1.5.23 (2014-03-12) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 05, 2014 at 01:44:24PM -0800, Olof Johansson wrote: > Pinctrl setup has traditionally always been done by firmware on x86, > and some ARM platforms are again moving back to that state (since > reconfiguring pinctrl in the kernel is in some cases not safe). > > What's the purpose of exposing this to the kernel on x86 now? I can > see the need to expose GPIO, but not pinctrl? Having the pin control > hidden away in firmware has been one of the benefits on x86, and > you're now undoing it... :) Well, the hardware is actually a pin controller so it can configure pins in different way. In addition to that we still do expect that the pins are configured by the BIOS for the time being. The advantage of having pinctrl driver is more like fixing things that the BIOS got wrong (like for example SPI pins that were muxed as GPIOs), not to reconfigure everything. Plus it has really nice debugfs interface :-) -- 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/