Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751817Ab3FZNZm (ORCPT ); Wed, 26 Jun 2013 09:25:42 -0400 Received: from devils.ext.ti.com ([198.47.26.153]:59081 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751368Ab3FZNZl (ORCPT ); Wed, 26 Jun 2013 09:25:41 -0400 Message-ID: <51CAEA90.90200@ti.com> Date: Wed, 26 Jun 2013 16:20:16 +0300 From: Grygorii Strashko User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130510 Thunderbird/17.0.6 MIME-Version: 1.0 To: Tony Lindgren CC: Linus Walleij , Kevin Hilman , Hebbar Gururaja , "linux-arm-kernel@lists.infradead.org" , Linux-OMAP , "linux-kernel@vger.kernel.org" , Stephen Warren Subject: Re: [RFC] ARM: OMAP2+: omap_device: add pinctrl handling References: <1371826990-25820-1-git-send-email-grygorii.strashko@ti.com> <20130625065811.GZ5523@atomide.com> In-Reply-To: <20130625065811.GZ5523@atomide.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5017 Lines: 119 Hi All, On 06/25/2013 09:58 AM, Tony Lindgren wrote: > * Linus Walleij [130624 05:13]: >> On Fri, Jun 21, 2013 at 5:03 PM, Grygorii Strashko >> wrote: >> >>> Hence, add pinctrl handling in omap_device core: >>> 1) on PM runtime resume >>> - switch pinctrl state to "default" (todo: "active") >>> 2) on PM runtime suspend >>> - switch pinctrl state to "idle" >>> 3) during system wide suspend >>> - switch pinctrl state to "sleep" or "idle" if omap_device core disables device >>> - switch pinctrl state to "sleep" if device is disabled already > Do you need a separate setting for "idle" and "sleep", or are > they the same? > >>> 4) during system wide resume >>> - switch pinctrl state to "default" (todo: "active") if omap_device core has >>> disabled device during suspend >>> - switch pinctrl state to "idle" if device was already disabled before suspend >> I don't understand step 4. >> >> I get the creeps about whether the system is runtime suspended >> or runtime resumed when we come to resume proper, so I need >> Kevin to have a look at this. >> >> Apart from that it looks good. >> >> Stephen and Tony are trying to figure out the details of whether "active" >> is necessary or not in a related thread I think. Thanks for your comments. I've prepared diagram to illustrate how does this work: + | | .probe() | +-----v--------+ | | | default | | | +----+--+------+ | | pm_runtime_get() | | pm_runtime_put() +------------------+ +------------------+ | | +------v--------+ pm_runtime_put() +-------v-------+ | +-----------------------> | +-----------> Active | pm_runtime_get() | Idle <--------------+ | | <-----------------------+ | | | +-------+-------+ +-------+-------+ | | |.suspend_noirq() |.suspend_noirq() | | | | | | | | | | | | | | | | | | +-------v-------+ +-------v--------+ | | | | | | | +-----------+ Sleep ------+ | Sleep +-------------+ .resume_noirq() | | | | |.resume_noirq() +-------|-------+ | +----------------+ | Idle | +-------------+ The "Sleep" pinctrl state is optional - if "sleep" state isn't defined then "Idle" pinctrl state will be used during suspend. As per above pinctrl state transition diagram - I think, that: - if "idle" or "sleep" states are defined then "active" state have to be defined too. So, pinctrl core should detect such situation and generate a warning. From my point of view, we should have "active" state - it would allow to avoid additional runtime overhead and handle properly the case when drivers are used as loadable modules. In this case, after boot, device's pinctrl registers can have HW default values (after reset) or can be configured to some safe (off) state from board file (board's "default" configuration). Driver module will activate its PINs when loaded and need to restore safe (off) PINs state when unloaded. As result, it seems, we should have "off" state which can be used when driver's module is removed. So, final list of default pnctrl states may be defined as "default", "active", "idle", "sleep", "off": - "active", "idle", "sleep": will be handled by omap_device core - "default", "off": will be handled by driver itself (or Device core). > Yes we should have that sorted out over next few weeks, so let's > just wait a little while on all these dynamic remuxing patches > to avoid churn. > > Regards, > > Tony Regards, - grygorii -- 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/