From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755100Ab2FNABn (ORCPT ); Wed, 13 Jun 2012 20:01:43 -0400 Received: from mailout4.samsung.com ([203.254.224.34]:28837 "EHLO mailout4.samsung.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754859Ab2FNABm (ORCPT ); Wed, 13 Jun 2012 20:01:42 -0400 X-AuditID: cbfee61b-b7fcc6d000003a7a-4b-4fd929e4fe21 From: Sangbeom Kim To: "'Mark Brown'" Cc: "'Liam Girdwood'" , linux-kernel@vger.kernel.org, sameo@linux.intel.com, sbkim01@gmail.com References: <042301cd493e$8d95d7e0$a8c187a0$@com> <20120613174620.GD7804@opensource.wolfsonmicro.com> In-reply-to: <20120613174620.GD7804@opensource.wolfsonmicro.com> Subject: RE: [PATCH 5/5] regulator: Support AP watchdog reset operation for s5m8767a Date: Thu, 14 Jun 2012 09:01:39 +0900 Message-id: <04ad01cd49c0$df565d20$9e031760$@com> MIME-version: 1.0 Content-type: text/plain; charset=us-ascii Content-transfer-encoding: 7bit X-Mailer: Microsoft Office Outlook 12.0 Thread-index: Ac1JjHMqiACEO2FHTSaGq+PpzOk8qQAMID9w Content-language: ko X-Brightmail-Tracker: H4sIAAAAAAAAA+NgFjrNLMWRmVeSWpSXmKPExsVy+t9jAd0nmjf9DQ7t07K4vGsOmwOjx+dN cgGMUVw2Kak5mWWpRfp2CVwZU++vZSp4zFMxY9Zr9gbGpVxdjJwcEgImEmf6drND2GISF+6t Z+ti5OIQEljEKLH2z2EWCGcuk8Tx6XdZQarYBDQkVu5+C1TFwSEiYCbx8yAPSJhZIEvi6fTj YCVCAukSG/7tYQOxOQUcJK4/W8wMYgsLhEn8uv2ZEaSVRUBV4kunCEiYV8BQ4nLfCyYIW1Di x+R7LBAjtSTW7zzOBGHLS2xe85YZpFVCQF3i0V9dkLCIgJHEkc17WCFKRCT2vXjHOIFRaBaS SbOQTJqFZNIsJC0LGFlWMYqmFiQXFCel5xrpFSfmFpfmpesl5+duYgQH8TPpHYyrGiwOMQpw MCrx8F5QuekvxJpYVlyZe4hRgoNZSYT3mQJQiDclsbIqtSg/vqg0J7X4EKM0B4uSOG+T9QV/ YJgklqRmp6YWpBbBZJk4OKUaGPulm9Z+qy1ef+fAtrokN8Ynje0MeXVdnXtUb9+3jNxbJ2Hz Tn/voaMta3bydjx21feYLBqVsTStxrxc7tfluWsPhsd5PN7ONHt62NbnN11kJBc/3dhsOzGh cYJz7bm1lXKM832as/r8Ve7cXVCYyTF7c/XEI/ssiuWK1Q9Wz77QGx8hKFcirsRSnJFoqMVc VJwIALGTEipeAgAA X-TM-AS-MML: No Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Mark, I'm sorry for insufficient explanation. Basically, PMIC can't know status of ap reset. Problem can be happened like below. - AP Bootable lowest arm voltage: 0.9v - AP arm voltage table for DVFS: 0.8v, 0.9v, 1.0v - During AP works on 0.8v, watchdog reset is asserted - AP can't boot, because vdd arm is still 0.8v Solution - Basic concept: After ap watchdog reset, GPIO configuration is changed by default value - S5M8767A has function of voltage control with gpio (8 levels with 3 gpios) - Set bootable voltage on level 0 -> can work with default gpio configuration - In the probing, Change voltage control level from level 0 to level 1 - Execute normal dvfs operation on level 1 - After watchdog reset, ap gpio is set by default value - PMIC operation mode is changed by ap reset (level1 -> level0) - AP can execute normal boot If you have any question, email me again. Thanks, Sangbeom. > -----Original Message----- > From: Mark Brown [mailto:broonie@opensource.wolfsonmicro.com] > Sent: Thursday, June 14, 2012 2:46 AM > To: Sangbeom Kim > Cc: 'Liam Girdwood'; linux-kernel@vger.kernel.org; sameo@linux.intel.com; sbkim01@gmail.com > Subject: Re: [PATCH 5/5] regulator: Support AP watchdog reset operation for s5m8767a > > On Wed, Jun 13, 2012 at 05:28:47PM +0900, Sangbeom Kim wrote: > > After AP watchdog reset, S5M8767A should be reset too. > > If AP is set on lowest voltage, AP can't execute boot sequence. > > This patch support watchdog reset of s5m8767. > > It's really hard to see how this patch addresses the issue above - could you explain in more > detail, please?