From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kishon Vijay Abraham I Subject: Re: [PATCH 1/2] ARM: dts: omap5-uevm: remove always_on, boot_on from smps10_out1 Date: Fri, 11 Oct 2013 12:24:56 +0530 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: quoted-printable Return-path: In-Reply-To: <5257A05B.2070906@ti.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Nishanth Menon 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" List-Id: devicetree@vger.kernel.org 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=92t want PMIC to enable it by default. I want the pa= lmas-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 ena= bled > by hardware. "If the regulator is not enabled by the hardware or bootload= er > 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 enabl= ing.. /* 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 =3D ops->enable(rdev); if (ret < 0) { rdev_err(rdev, "failed to enable\n"); goto out; } } Thanks Kishon