Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758529Ab3JKPsP (ORCPT ); Fri, 11 Oct 2013 11:48:15 -0400 Received: from mho-02-ewr.mailhop.org ([204.13.248.72]:27237 "EHLO mho-02-ewr.mailhop.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758410Ab3JKPsL (ORCPT ); Fri, 11 Oct 2013 11:48:11 -0400 X-Mail-Handler: Dyn Standard SMTP by Dyn X-Originating-IP: 50.131.214.131 X-Report-Abuse-To: abuse@dyndns.com (see http://www.dyndns.com/services/sendlabs/outbound_abuse.html for abuse reporting information) X-MHO-User: U2FsdGVkX19oSpKaeOgcWpSAU8j/7vir Date: Fri, 11 Oct 2013 08:48:05 -0700 From: Tony Lindgren To: Balaji T K Cc: Roger Quadros , Linus Walleij , "linux-arm-kernel@lists.infradead.org" , "devicetree@vger.kernel.org" , Grygorii Strashko , "linux-kernel@vger.kernel.org" , Peter Ujfalusi , Haojian Zhuang , =?utf-8?Q?Beno=C3=AEt?= Cousson , Linux-OMAP Subject: Re: [PATCH 4/6] pinctrl: single: Add support for wake-up interrupts Message-ID: <20131011154804.GP29913@atomide.com> References: <20131003054104.8941.88857.stgit@localhost> <20131003054221.8941.87801.stgit@localhost> <5256AA7F.8030005@ti.com> <20131010160018.GA29913@atomide.com> <20131010162015.GC29913@atomide.com> <5257BD3E.5000707@ti.com> <20131011153654.GN29913@atomide.com> <52581CA7.20606@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52581CA7.20606@ti.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2111 Lines: 44 * Balaji T K [131011 08:51]: > On Friday 11 October 2013 09:06 PM, Tony Lindgren wrote: > >>>What the pin control driver should do is control the pins. Whether the registers > >>>are spread out in the entire IO-memory does not matter. We did have one system > >>>which placed the IO-muxing together with each peripheral (!) and I did > >>>still want > >>>that to be handled by a single pinctrl driver picking out windows to all these > >>>IO-ranges. > >>> > >>>Things like the PRM which has (my guess) a gazillion registers related to its > >>>deep-core SoC stuff should be handled by things like > >>>drivers/mfd/syscon.c, which means it is dead simple for some other driver > >>>using "just this one register" in that range to get a handle at it and poke it > >>>using syscon_node_to_regmap() (just derference an ampersand ref) > >>>syscon_regmap_lookup_by_compatible() (use a compatible string) > >>>all returning a regmap * that you can use to poke these registers. > >> > >>The register handling is fine. But how do we deal with resource handling? > >>e.g. the block that has the deep-core registers might need to be clocked or powered > >>before the registers can be accessed. > > > >Right, that's the key issue here. The register access would have to be conditional > >based on the hardware modules PM state. Otherwise we'll have hard to trace hangs > >and oopses. > > > Hi Tony, > > How are the clocks/power state currently handled in case of omap4_pmx_core, > omap4_pmx_wkup register access via pinctrl-single ? It's currently always on during runtime and managed in for the whole SCM by mach-omap2/control.c. Then there's a separate SCM register that triggers the save and restore of the padconf registers in hardware for off-idle along with other SCM related things, see the *_control_save/restore_context() functions. Regards, Tony -- 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/