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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 6587BC432C0 for ; Fri, 29 Nov 2019 11:03:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3FBF521843 for ; Fri, 29 Nov 2019 11:03:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726780AbfK2LDA (ORCPT ); Fri, 29 Nov 2019 06:03:00 -0500 Received: from relay10.mail.gandi.net ([217.70.178.230]:35767 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726215AbfK2LDA (ORCPT ); Fri, 29 Nov 2019 06:03:00 -0500 Received: from localhost (lfbn-1-1480-129.w90-65.abo.wanadoo.fr [90.65.102.129]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 4286224000D; Fri, 29 Nov 2019 11:02:57 +0000 (UTC) Date: Fri, 29 Nov 2019 12:02:53 +0100 From: Alexandre Belloni To: Claudiu.Beznea@microchip.com Cc: kamel.bouhara@bootlin.com, sre@kernel.org, Nicolas.Ferre@microchip.com, Ludovic.Desroches@microchip.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org, thomas.petazzoni@bootlin.com Subject: Re: [PATCH] power: reset: at91-reset: add sysfs interface to the power on reason Message-ID: <20191129110253.GX299836@piout.net> References: <20191017124058.19300-1-kamel.bouhara@bootlin.com> <034c9d01-633a-eeaa-f61f-d185be7227f2@microchip.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <034c9d01-633a-eeaa-f61f-d185be7227f2@microchip.com> User-Agent: Mutt/1.12.1 (2019-06-15) Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org On 29/11/2019 10:57:45+0000, Claudiu.Beznea@microchip.com wrote: > Hi Kamel, > > On 17.10.2019 15:40, Kamel Bouhara wrote: > > This patch export the power on reason through the sysfs interface and > > introduce some generic reset sources. > > Update the ABI documentation to list current power on sources. > > > > Signed-off-by: Kamel Bouhara > > --- > > .../sysfs-devices-platform-power-on-reason | 14 ++++++ > > drivers/power/reset/at91-reset.c | 44 +++++++++++++------ > > include/linux/power/power_on_reason.h | 19 ++++++++ > > 3 files changed, 64 insertions(+), 13 deletions(-) > > create mode 100644 Documentation/ABI/testing/sysfs-devices-platform-power-on-reason > > create mode 100644 include/linux/power/power_on_reason.h > > > > diff --git a/Documentation/ABI/testing/sysfs-devices-platform-power-on-reason b/Documentation/ABI/testing/sysfs-devices-platform-power-on-reason > > new file mode 100644 > > index 000000000000..83daeb9b1aa2 > > --- /dev/null > > +++ b/Documentation/ABI/testing/sysfs-devices-platform-power-on-reason > > @@ -0,0 +1,14 @@ > > +What: /sys/devices/platform/.../power_on_reason > > + > > +Date: October 2019 > > +KernelVersion: 5.4 > > +Contact: Kamel Bouhara > > +Description: This file shows system power on reason. > > + The possible sources are: > > + General System Power-ON, RTC wakeup, Watchdog timeout, > > + Software Reset, User pressed reset button, > > + CPU Clock failure, 32.768kHz Oscillator Failure, > > + Low power mode exit, Unknown. > > + > > + The file is read only. > > + > > diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c > > index 44ca983a49a1..3cb2df40af37 100644 > > --- a/drivers/power/reset/at91-reset.c > > +++ b/drivers/power/reset/at91-reset.c > > @@ -17,7 +17,7 @@ > > #include > > #include > > #include > > - > > +#include > > #include > > #include > > > > @@ -146,42 +146,42 @@ static int samx7_restart(struct notifier_block *this, unsigned long mode, > > return NOTIFY_DONE; > > } > > > > -static void __init at91_reset_status(struct platform_device *pdev) > > +static const char *at91_reset_reason(struct platform_device *pdev) > > { > > const char *reason; > > u32 reg = readl(at91_rstc_base + AT91_RSTC_SR); > > > > switch ((reg & AT91_RSTC_RSTTYP) >> 8) { > > case RESET_TYPE_GENERAL: > > - reason = "general reset"; > > + reason = POWER_ON_REASON_GENERAL; > > break; > > case RESET_TYPE_WAKEUP: > > - reason = "wakeup"; > > + reason = POWER_ON_REASON_RTC; > > break; > > case RESET_TYPE_WATCHDOG: > > - reason = "watchdog reset"; > > + reason = POWER_ON_REASON_WATCHDOG; > > break; > > case RESET_TYPE_SOFTWARE: > > - reason = "software reset"; > > + reason = POWER_ON_REASON_SOFTWARE; > > break; > > case RESET_TYPE_USER: > > - reason = "user reset"; > > + reason = POWER_ON_REASON_USER; > > break; > > case RESET_TYPE_CPU_FAIL: > > - reason = "CPU clock failure detection"; > > + reason = POWER_ON_REASON_CPU_FAIL; > > break; > > case RESET_TYPE_XTAL_FAIL: > > - reason = "32.768 kHz crystal failure detection"; > > + reason = POWER_ON_REASON_XTAL_FAIL; > > break; > > case RESET_TYPE_ULP2: > > - reason = "ULP2 reset"; > > + reason = POWER_ON_REASON_LOW_POWER; > > break; > > default: > > - reason = "unknown reset"; > > + reason = POWER_ON_REASON_UNKNOWN; > > break; > > } > > > > - dev_info(&pdev->dev, "Starting after %s\n", reason); > > + return reason; > > } > > > > static const struct of_device_id at91_ramc_of_match[] = { > > @@ -204,6 +204,17 @@ static struct notifier_block at91_restart_nb = { > > .priority = 192, > > }; > > > > +static ssize_t power_on_reason_show(struct device *dev, > > + struct device_attribute *attr, > > + char *buf) > > +{ > > + struct platform_device *pdev = to_platform_device(dev); > > + > > + return sprintf(buf, "%s\n", at91_reset_reason(pdev)); > > +} > > + > > +static DEVICE_ATTR_RO(power_on_reason); > > + > > static int __init at91_reset_probe(struct platform_device *pdev) > > { > > const struct of_device_id *match; > > @@ -248,7 +259,14 @@ static int __init at91_reset_probe(struct platform_device *pdev) > > return ret; > > } > > > > - at91_reset_status(pdev); > > + ret = device_create_file(&pdev->dev, &dev_attr_power_on_reason); > > + if (ret) { > > + dev_err(&pdev->dev, "Could not create sysfs entry\n"); > > + return ret; > > + } > > + > > + dev_info(&pdev->dev, "Starting after %s reset\n", > > + at91_reset_reason(pdev)); > > > > return 0; > > } > > diff --git a/include/linux/power/power_on_reason.h b/include/linux/power/power_on_reason.h > > new file mode 100644 > > index 000000000000..9978cc757427 > > --- /dev/null > > +++ b/include/linux/power/power_on_reason.h > > @@ -0,0 +1,19 @@ > > +/* SPDX-License-Identifier: GPL-2.0-only */ > > +/* > > + * Author: Kamel Bouhra > > + */ > > + > > +#ifndef POWER_ON_REASON_H > > +#define POWER_ON_REASON_H > > + > > +#define POWER_ON_REASON_GENERAL "General" > > +#define POWER_ON_REASON_RTC "RTC wakeup" > > +#define POWER_ON_REASON_WATCHDOG "Watchdog timeout" > > +#define POWER_ON_REASON_SOFTWARE "Software" > > +#define POWER_ON_REASON_USER "User" > > +#define POWER_ON_REASON_CPU_FAIL "CPU Clock Failure" > > +#define POWER_ON_REASON_XTAL_FAIL "32.768k Crystal oscillator Failure" > > +#define POWER_ON_REASON_LOW_POWER "Low power exit" > > +#define POWER_ON_REASON_UNKNOWN "Unknown" > > + > > +#endif /* POWER_ON_REASON_H */ > > Is this new header necessary? > Yes because we want other drivers to be able to reuse them as-is so the ABI is stable. -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com