From patchwork Tue Jun 20 06:26:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Miquel Raynal X-Patchwork-Id: 13285207 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id AEBF3EB64D7 for ; Tue, 20 Jun 2023 06:27:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229731AbjFTG1C (ORCPT ); Tue, 20 Jun 2023 02:27:02 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41690 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229597AbjFTG1C (ORCPT ); Tue, 20 Jun 2023 02:27:02 -0400 Received: from relay2-d.mail.gandi.net (relay2-d.mail.gandi.net [217.70.183.194]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A93B81A5 for ; Mon, 19 Jun 2023 23:27:00 -0700 (PDT) X-GND-Sasl: miquel.raynal@bootlin.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bootlin.com; s=gm1; t=1687242419; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version: content-transfer-encoding:content-transfer-encoding; bh=7pl6qCNBQeotbXsdQRYataHay2+MrATT6vr5AKa1Xc8=; b=n0DLBu/0zLrq8qT4ZF0wn6HAIyqtn4wQMCPiYIDg+qNZcEkLArU7QPCOWAcUrxng5u+k8e 0DsaH6TPnKLn9WqeNxmG+UEBNsID/fpHmRgGX1fdPX2n2PzXTs+C9l3BiZs5b5tifWyv9i KYyFVqVMNd2GLPWMB3BW+3swrHAnx/3eWdst7C5nFZnAsGag6bpLDXVAd80W3Z/GO6zVqj gWOIvkxXdvUWpczm0oo3epTKFCWpnXk18lJ+nDx/q+FTZCSXMsyIO4E9zxJB4KdsP5t11J qZip9iV/yQ/NkOiPNCZlWXcsyn/HnQDiW+MPEvpmKnFVRjQoOwBqAzEsvUAQsg== X-GND-Sasl: miquel.raynal@bootlin.com X-GND-Sasl: miquel.raynal@bootlin.com X-GND-Sasl: miquel.raynal@bootlin.com X-GND-Sasl: miquel.raynal@bootlin.com X-GND-Sasl: miquel.raynal@bootlin.com X-GND-Sasl: miquel.raynal@bootlin.com X-GND-Sasl: miquel.raynal@bootlin.com X-GND-Sasl: miquel.raynal@bootlin.com Received: by mail.gandi.net (Postfix) with ESMTPSA id 6FD6D40007; Tue, 20 Jun 2023 06:26:58 +0000 (UTC) From: Miquel Raynal To: Sebastian Reichel Cc: Thomas Petazzoni , Alexandre Belloni , Claudiu Beznea , linux-pm@vger.kernel.org, , Kamel Bouhara , Nicolas Ferre , Miquel Raynal Subject: [PATCH v4] power: reset: at91-reset: add sysfs interface to the power on reason Date: Tue, 20 Jun 2023 08:26:57 +0200 Message-Id: <20230620062657.3127468-1-miquel.raynal@bootlin.com> X-Mailer: git-send-email 2.34.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org From: Kamel Bouhara Introduce a list of generic reset sources and use them to export the power on reason through sysfs. Update the ABI documentation to describe this new interface. Signed-off-by: Kamel Bouhara Acked-by: Nicolas Ferre [Miquel Raynal: Follow-up on Kamel's work, 4 years later] Signed-off-by: Miquel Raynal --- Changes in v4: * Patch 1/2 was merged. * Changed the "low-power condition" into a "brown-out reset" as suggested by Sebastian. Changes in v3: * Made the series bisectable. * Updated the date and kernel version for this new feature. * Changed a few definitions as discussed with Sebastian. Changes in v2: * Collected Nicolas' Acked-by * Dropped the Xtal frequency information (as this may change between platforms of course). .../testing/sysfs-platform-power-on-reason | 12 ++++++ drivers/power/reset/at91-reset.c | 37 ++++++++++++++----- include/linux/power/power_on_reason.h | 19 ++++++++++ 3 files changed, 58 insertions(+), 10 deletions(-) create mode 100644 Documentation/ABI/testing/sysfs-platform-power-on-reason create mode 100644 include/linux/power/power_on_reason.h diff --git a/Documentation/ABI/testing/sysfs-platform-power-on-reason b/Documentation/ABI/testing/sysfs-platform-power-on-reason new file mode 100644 index 000000000000..c3b29dbc64bf --- /dev/null +++ b/Documentation/ABI/testing/sysfs-platform-power-on-reason @@ -0,0 +1,12 @@ +What: /sys/devices/platform/.../power_on_reason +Date: June 2023 +KernelVersion: 6.5 +Contact: Kamel Bouhara +Description: Shows system power on reason. The following strings/reasons can + be read (the list can be extended): + "regular power-up", "RTC wakeup", "watchdog timeout", + "software reset", "reset button action", "CPU clock failure", + "crystal oscillator failure", "brown-out reset", + "unknown reason". + + The file is read only. diff --git a/drivers/power/reset/at91-reset.c b/drivers/power/reset/at91-reset.c index d6884841a6dc..aa9b012d3d00 100644 --- a/drivers/power/reset/at91-reset.c +++ b/drivers/power/reset/at91-reset.c @@ -18,6 +18,7 @@ #include #include #include +#include #include #include @@ -149,44 +150,54 @@ static int at91_reset(struct notifier_block *this, unsigned long mode, return NOTIFY_DONE; } -static const char * __init at91_reset_reason(struct at91_reset *reset) +static const char *at91_reset_reason(struct at91_reset *reset) { u32 reg = readl(reset->rstc_base + AT91_RSTC_SR); const char *reason; switch ((reg & AT91_RSTC_RSTTYP) >> 8) { case RESET_TYPE_GENERAL: - reason = "general reset"; + reason = POWER_ON_REASON_REGULAR; 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_RST_BTN; break; case RESET_TYPE_CPU_FAIL: - reason = "CPU clock failure detection"; + reason = POWER_ON_REASON_CPU_CLK_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_BROWN_OUT; break; default: - reason = "unknown reset"; + reason = POWER_ON_REASON_UNKNOWN; break; } return reason; } +static ssize_t power_on_reason_show(struct device *dev, + struct device_attribute *attr, char *buf) +{ + struct platform_device *pdev = to_platform_device(dev); + struct at91_reset *reset = platform_get_drvdata(pdev); + + return sprintf(buf, "%s\n", at91_reset_reason(reset)); +} +static DEVICE_ATTR_RO(power_on_reason); + static const struct of_device_id at91_ramc_of_match[] = { { .compatible = "atmel,at91sam9260-sdramc", @@ -391,6 +402,12 @@ static int __init at91_reset_probe(struct platform_device *pdev) if (ret) goto disable_clk; + 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\n", at91_reset_reason(reset)); 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..95a1ec0c403c --- /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_REGULAR "regular power-up" +#define POWER_ON_REASON_RTC "RTC wakeup" +#define POWER_ON_REASON_WATCHDOG "watchdog timeout" +#define POWER_ON_REASON_SOFTWARE "software reset" +#define POWER_ON_REASON_RST_BTN "reset button action" +#define POWER_ON_REASON_CPU_CLK_FAIL "CPU clock failure" +#define POWER_ON_REASON_XTAL_FAIL "crystal oscillator failure" +#define POWER_ON_REASON_BROWN_OUT "brown-out reset" +#define POWER_ON_REASON_UNKNOWN "unknown reason" + +#endif /* POWER_ON_REASON_H */