From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2D37EC10F13 for ; Mon, 8 Apr 2019 17:26:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 0983A213F2 for ; Mon, 8 Apr 2019 17:26:59 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726750AbfDHR06 (ORCPT ); Mon, 8 Apr 2019 13:26:58 -0400 Received: from muru.com ([72.249.23.125]:44812 "EHLO muru.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726635AbfDHR06 (ORCPT ); Mon, 8 Apr 2019 13:26:58 -0400 Received: from atomide.com (localhost [127.0.0.1]) by muru.com (Postfix) with ESMTPS id 7D2D680AA; Mon, 8 Apr 2019 17:27:12 +0000 (UTC) Date: Mon, 8 Apr 2019 10:26:54 -0700 From: Tony Lindgren To: Keerthy Cc: alexandre.belloni@bootlin.com, a.zummo@towertech.it, t-kristo@ti.com, ssantosh@kernel.org, d-gerlach@ti.com, linux-omap@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-rtc@vger.kernel.org Subject: Re: [PATCH v3 0/4] AM437x: Add rtc-only + DDR mode support Message-ID: <20190408172654.GL49658@atomide.com> References: <20190403045742.2243-1-j-keerthy@ti.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190403045742.2243-1-j-keerthy@ti.com> User-Agent: Mutt/1.11.4 (2019-03-13) Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org * Keerthy [190402 21:57]: > RTC plus DDR in self-refresh is a power saving mode where in the entire > system including the different voltage rails from PMIC are shutdown except > the ones feeding on to RTC and DDR. DDR is kept in self-refresh hence the > contents are preserved. > > RTC ALARM2 is connected to PMIC_EN line. TPS65218 PMIC has granular voltage rail > control. The voltage rail feeding RTC is kept on while the rest of the PMIC > regulators are powered off. > > Once the ALARM2 is triggered we enter the mode with DDR in self-refresh > and RTC Ticking. After a predetermined time an RTC ALARM1 triggers > waking up the system. The control goes to bootloader. The bootloader then checks > RTC scratchpad registers to confirm it was an rtc_only wakeup and follows > a different path, configure bare minimal clocks for ddr and then jumps to > the resume address in another RTC scratchpad registers and transfers the > control to Kernel. Kernel then restores the saved context. > > The patch series adds rtc-only + DDR mode support am am437x > Tested DS0, rtc+ddr back and forth on am437x-gp-evm board. > > This mode works only with u-boot built with am43xx_evm_rtconly_defconfig > > Additional patch is needed for omap-gpio save restore which will > come as fixes later. > > Hardware Description of this mode can be found here: > > http://www.ti.com/lit/ug/spruhl7h/spruhl7h.pdf Page 2884. > > Changes in v3: > > * Exported out omap_rtc_poweroff_program function & removed > the patch to add a generic rtc interface as it is specific > to am43 at the moment. Thanks I'll be applying this series into omap-for-v5.2/am4-pm today. Regards, Tony