From patchwork Fri Oct 11 07:27:02 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Nishanth Menon X-Patchwork-Id: 3021251 Return-Path: X-Original-To: patchwork-linux-omap@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork1.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork1.web.kernel.org (Postfix) with ESMTP id 7AB969F243 for ; Fri, 11 Oct 2013 07:27:25 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7E03C20328 for ; Fri, 11 Oct 2013 07:27:24 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FE9D20320 for ; Fri, 11 Oct 2013 07:27:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757103Ab3JKH1G (ORCPT ); Fri, 11 Oct 2013 03:27:06 -0400 Received: from mail-wg0-f49.google.com ([74.125.82.49]:62137 "EHLO mail-wg0-f49.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756351Ab3JKH1E convert rfc822-to-8bit (ORCPT ); Fri, 11 Oct 2013 03:27:04 -0400 Received: by mail-wg0-f49.google.com with SMTP id x12so1504253wgg.4 for ; Fri, 11 Oct 2013 00:27:02 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:date:message-id:subject :from:to:cc:content-type:content-transfer-encoding; bh=TRkBCMMuxSyFZTgQnMfNU0m7+QbCajOvO/tfa1HdU3M=; b=Cg9UAIMYJHOODZxxH68+xQFOEEoSLwe4BS25Udbz9ZBp2YJJzqKtwdqgb2ibGN8sln Ng74QAcu7NAzbRoqYfBLuNAgoGtFZuA7oVXaxzcmPrFvaOWuDzB/+Zql/iz5XptAZ++i NwBosN9nOG+QoLvkkDPomKS4rpUeUwtNHZCaXrUObmxq8j4ydatlI2MFwnFviw2ednD+ Lcxaf2QEJ/DndosYTPk/S5N+fsGmRBm0wBh1I9ZdzRexHIsbqAEeAIzFRuj1NLAZW48b jHZaPochlM3ubUTPZIYtRI4LSTs6BIBle/0XMabKEN2u74PjwlHqEB8FIHqx+fhxQlty Inhw== MIME-Version: 1.0 X-Received: by 10.194.109.68 with SMTP id hq4mr16004454wjb.12.1381476422270; Fri, 11 Oct 2013 00:27:02 -0700 (PDT) Received: by 10.216.209.77 with HTTP; Fri, 11 Oct 2013 00:27:02 -0700 (PDT) In-Reply-To: <5257A0C0.8000701@ti.com> References: <1381402195-29257-1-git-send-email-kishon@ti.com> <20131010141949.GA13277@kahuna> <52579723.6080209@ti.com> <5257A05B.2070906@ti.com> <5257A0C0.8000701@ti.com> Date: Fri, 11 Oct 2013 02:27:02 -0500 X-Google-Sender-Auth: TJn5X7kQu56yLIA42sdRGAI5KrQ Message-ID: Subject: Re: [PATCH 1/2] ARM: dts: omap5-uevm: remove always_on, boot_on from smps10_out1 From: Nishanth Menon To: Kishon Vijay Abraham I Cc: Mark Rutland , dt list , Russell King - ARM Linux , Pawel Moll , "ijc+devicetree@hellion.org.uk" , Tony Lindgren , Stephen Warren , lkml , Rob Herring , Benoit Cousson , linux-omap , "linux-arm-kernel@lists.infradead.org" Sender: linux-omap-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-omap@vger.kernel.org X-Spam-Status: No, score=-7.0 required=5.0 tests=BAYES_00,DKIM_SIGNED, RCVD_IN_DNSWL_HI,RP_MATCHES_RCVD,T_DKIM_INVALID,UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP On Fri, Oct 11, 2013 at 1:54 AM, Kishon Vijay Abraham I wrote: > On Friday 11 October 2013 12:23 PM, Kishon Vijay Abraham I wrote: >> Hi, >> >> On Friday 11 October 2013 12:00 PM, Nishanth Menon wrote: >>> On Fri, Oct 11, 2013 at 1:13 AM, Kishon Vijay Abraham I wrote: >>>> >>>>> regulator-boot-on indicates that PMIC enables it by default as part of >>>>> OTP or some internal behavior -> Looking at the measurements done on >>>>> uEVM and OTP information -> regulator-boot-on should be kept here. >>>> >>>> No. Actually I don’t want PMIC to enable it by default. I want the palmas-usb >>>> driver to handle it. >>>> Enabling it by default makes palmas-usb to detect VBUS interrupt. This should >>>> ideally be detected only when you connect a host cable. >>>> Btw I didn't exactly get why you want regulator-boot-on should be kept here. >>> >>> binding description states: >>> - regulator-boot-on: bootloader/firmware enabled regulator >>> Further info: include/linux/regulator/machine.h >>> * @boot_on: Set if the regulator is enabled when the system is initially >>> * started. If the regulator is not enabled by the hardware or >>> * bootloader then it will be enabled when the constraints are >>> * applied. >>> >>> What that means is that it is enabled by firmware/bootloader (in our >>> case One Time Program {OTP} inside Palmas) when the system switches on >>> even before the kernel starts. and we know SMPS10 is autoenabled by >>> Palmas OTP configuration even before first instruction in A15 >>> executes. >> >> Not sure about that. Please note SMPS10 has two outputs OUT1 and OUT2 and I >> tend to think that it might be OUT2 that's getting enabled by the OTP. >>> >>> I think you misunderstand this to mean that you'd like the regulator >>> to be *switched on* automatically at kernel boot by regulator >>> framework - there is no reasoning why we'd want such a binding since >>> we'd expect drivers to do their job of requesting and enabling >>> regulators on need.. >> >> The comment you just quoted tells it enables the regulator if its not enabled >> by hardware. "If the regulator is not enabled by the hardware or bootloader >> then it will be enabled when the constraints are applied." At-least that's what >> I understood from that comment. >> >> Also from our experiments it doesn't look like SMPS10_OUT1 is enabled by the >> OTP and it gets enabled when we have *regulator-boot-on* constraints. > > btw.. I think this is the code in regulator fw that's responsible for enabling.. > > /* If the constraints say the regulator should be on at this point > * and we have control then make sure it is enabled. > */ > if ((rdev->constraints->always_on || rdev->constraints->boot_on) && > ops->enable) { > ret = ops->enable(rdev); > if (ret < 0) { > rdev_err(rdev, "failed to enable\n"); > goto out; > } > } Drat, you are right, I did not really dig deep. thanks for correcting my understanding here. I propose the following change in binding as it seems completely misleading to me. --- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/Documentation/devicetree/bindings/regulator/regulator.txt b/Documentation/devicetree/bindings/regulator/regulator.txt index 2bd8f09..d999f096 100644 --- a/Documentation/devicetree/bindings/regulator/regulator.txt +++ b/Documentation/devicetree/bindings/regulator/regulator.txt @@ -8,7 +8,9 @@ Optional properties: - regulator-min-microamp: smallest current consumers may set - regulator-max-microamp: largest current consumers may set - regulator-always-on: boolean, regulator should never be disabled -- regulator-boot-on: bootloader/firmware enabled regulator +- regulator-boot-on: regulator is enabled when the system is initially started. + If the regulator is not enabled by the hardware or bootloader then it will be + enabled when the constraints are applied. - regulator-allow-bypass: allow the regulator to go into bypass mode - -supply: phandle to the parent supply/regulator node - regulator-ramp-delay: ramp delay for regulator(in uV/uS)