From mboxrd@z Thu Jan 1 00:00:00 1970 From: Keerthy Subject: Re: [PATCH V2 2/2] ARM: dts: DRA7: Add node for RTC Date: Tue, 15 Jul 2014 09:21:38 +0530 Message-ID: <53C4A54A.1070500@ti.com> References: <1404894932-26677-1-git-send-email-lokeshvutla@ti.com> <1404894932-26677-3-git-send-email-lokeshvutla@ti.com> <20140709091232.GJ28884@atomide.com> <53BD0C43.1090002@ti.com> <20140709100914.GL28884@atomide.com> <53BD1AF8.2060609@ti.com> <20140709105055.GP28884@atomide.com> <53BD1FC3.6050500@ti.com> <20140709110051.GQ28884@atomide.com> <53BD2249.2080808@ti.com> <53C3ED02.7020206@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from bear.ext.ti.com ([192.94.94.41]:33180 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753577AbaGODxz (ORCPT ); Mon, 14 Jul 2014 23:53:55 -0400 In-Reply-To: <53C3ED02.7020206@ti.com> Sender: linux-omap-owner@vger.kernel.org List-Id: linux-omap@vger.kernel.org To: Lokesh Vutla Cc: Tony Lindgren , paul@pwsan.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, rnayak@ti.com, devicetree@vger.kernel.org, nm@ti.com, j-keerthy@ti.com, nsekhar@ti.com On Monday 14 July 2014 08:15 PM, Lokesh Vutla wrote: > Hi Tony, > On Wednesday 09 July 2014 04:36 PM, Keerthy wrote: >> On Wednesday 09 July 2014 04:30 PM, Tony Lindgren wrote: >>> * Keerthy [140709 03:59]: >>>> On Wednesday 09 July 2014 04:20 PM, Tony Lindgren wrote: >>>>> * Keerthy [140709 03:39]: >>>>>> On Wednesday 09 July 2014 03:39 PM, Tony Lindgren wrote: >>>>>>> * Keerthy [140709 02:36]: >>>>>>>> On Wednesday 09 July 2014 02:42 PM, Tony Lindgren wrote: >>>>>>>>> * Lokesh Vutla [140709 01:37]: >>>>>>>>>> --- a/arch/arm/boot/dts/dra7-evm.dts >>>>>>>>>> +++ b/arch/arm/boot/dts/dra7-evm.dts >>>>>>>>>> @@ -249,6 +249,7 @@ >>>>>>>>>> regulator-min-microvolt = <1050000>; >>>>>>>>>> regulator-max-microvolt = <1050000>; >>>>>>>>>> regulator-boot-on; >>>>>>>>>> + regulator-always-on; >>>>>>>>>> }; >>>>>>>>> Is this regulator really always on? >>>>>>>> This feeds on to RTC which is a free running clock. So i guess always on is >>>>>>>> justified no? >>>>>>> Well the dts entries should describe the hardware. If the >>>>>>> regulator can be enabled and disabled, we should not claim it's >>>>>>> always on. >>>>>> From the PMIC perspective every regulator can be enabled and >>>>>> disabled. From a Board perspective there are some which need >>>>>> to be always on. For Ex: SMPS123 which feeds on to the MPU. >>>>> Right, and we already have regulator-boot-on for those. Or are >>>>> you seeing some issue with that? >>>> regulator-boot-on describes that at boot a particular regulator is on. >>>> It does not guarantee that it will be on for the rest of the time. The >>>> regulator framework can go ahead and disable it if no one has requested >>>> for it. In case of RTC we do not want that to happen. >>> That's a bug in the RTC driver then. The driver should request a >>> regulator if it's specified. > In my experiments I observed that when RTC regulator is switched off and switched on, there is an abort while > accessing RTC registers. > After discussing with hardware team, it is confirmed that this LDO9 regulator powering RTC cannot be turned off when > SoC is active and expected to be always on. As confirmed by the PMIC hardware team this regulator should be an always-on regulator. Acked-by: Keerthy > > Thanks and regards, > Lokesh > >> Okay. >> >>> Regards, >>> >>> Tony From mboxrd@z Thu Jan 1 00:00:00 1970 From: a0393675@ti.com (Keerthy) Date: Tue, 15 Jul 2014 09:21:38 +0530 Subject: [PATCH V2 2/2] ARM: dts: DRA7: Add node for RTC In-Reply-To: <53C3ED02.7020206@ti.com> References: <1404894932-26677-1-git-send-email-lokeshvutla@ti.com> <1404894932-26677-3-git-send-email-lokeshvutla@ti.com> <20140709091232.GJ28884@atomide.com> <53BD0C43.1090002@ti.com> <20140709100914.GL28884@atomide.com> <53BD1AF8.2060609@ti.com> <20140709105055.GP28884@atomide.com> <53BD1FC3.6050500@ti.com> <20140709110051.GQ28884@atomide.com> <53BD2249.2080808@ti.com> <53C3ED02.7020206@ti.com> Message-ID: <53C4A54A.1070500@ti.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On Monday 14 July 2014 08:15 PM, Lokesh Vutla wrote: > Hi Tony, > On Wednesday 09 July 2014 04:36 PM, Keerthy wrote: >> On Wednesday 09 July 2014 04:30 PM, Tony Lindgren wrote: >>> * Keerthy [140709 03:59]: >>>> On Wednesday 09 July 2014 04:20 PM, Tony Lindgren wrote: >>>>> * Keerthy [140709 03:39]: >>>>>> On Wednesday 09 July 2014 03:39 PM, Tony Lindgren wrote: >>>>>>> * Keerthy [140709 02:36]: >>>>>>>> On Wednesday 09 July 2014 02:42 PM, Tony Lindgren wrote: >>>>>>>>> * Lokesh Vutla [140709 01:37]: >>>>>>>>>> --- a/arch/arm/boot/dts/dra7-evm.dts >>>>>>>>>> +++ b/arch/arm/boot/dts/dra7-evm.dts >>>>>>>>>> @@ -249,6 +249,7 @@ >>>>>>>>>> regulator-min-microvolt = <1050000>; >>>>>>>>>> regulator-max-microvolt = <1050000>; >>>>>>>>>> regulator-boot-on; >>>>>>>>>> + regulator-always-on; >>>>>>>>>> }; >>>>>>>>> Is this regulator really always on? >>>>>>>> This feeds on to RTC which is a free running clock. So i guess always on is >>>>>>>> justified no? >>>>>>> Well the dts entries should describe the hardware. If the >>>>>>> regulator can be enabled and disabled, we should not claim it's >>>>>>> always on. >>>>>> From the PMIC perspective every regulator can be enabled and >>>>>> disabled. From a Board perspective there are some which need >>>>>> to be always on. For Ex: SMPS123 which feeds on to the MPU. >>>>> Right, and we already have regulator-boot-on for those. Or are >>>>> you seeing some issue with that? >>>> regulator-boot-on describes that at boot a particular regulator is on. >>>> It does not guarantee that it will be on for the rest of the time. The >>>> regulator framework can go ahead and disable it if no one has requested >>>> for it. In case of RTC we do not want that to happen. >>> That's a bug in the RTC driver then. The driver should request a >>> regulator if it's specified. > In my experiments I observed that when RTC regulator is switched off and switched on, there is an abort while > accessing RTC registers. > After discussing with hardware team, it is confirmed that this LDO9 regulator powering RTC cannot be turned off when > SoC is active and expected to be always on. As confirmed by the PMIC hardware team this regulator should be an always-on regulator. Acked-by: Keerthy > > Thanks and regards, > Lokesh > >> Okay. >> >>> Regards, >>> >>> Tony