From nobody Wed Dec 17 11:33:41 2025 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 4A2A9C25B48 for ; Thu, 26 Oct 2023 14:48:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345362AbjJZOs6 (ORCPT ); Thu, 26 Oct 2023 10:48:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46232 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S235105AbjJZOso (ORCPT ); Thu, 26 Oct 2023 10:48:44 -0400 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [IPv6:2a0a:edc0:2:b01:1d::104]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15F151AE for ; Thu, 26 Oct 2023 07:48:41 -0700 (PDT) Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1qw1es-0005Zq-2D; Thu, 26 Oct 2023 16:48:26 +0200 Received: from [2a0a:edc0:0:1101:1d::ac] (helo=dude04.red.stw.pengutronix.de) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1qw1er-004Qq4-JD; Thu, 26 Oct 2023 16:48:25 +0200 Received: from ore by dude04.red.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1qw1er-00H3Xj-1g; Thu, 26 Oct 2023 16:48:25 +0200 From: Oleksij Rempel To: Liam Girdwood , Mark Brown , Rob Herring , Krzysztof Kozlowski , Conor Dooley Cc: Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: [PATCH v4 2/5] regulator: Introduce handling for system-critical under-voltage events Date: Thu, 26 Oct 2023 16:48:21 +0200 Message-Id: <20231026144824.4065145-3-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20231026144824.4065145-1-o.rempel@pengutronix.de> References: <20231026144824.4065145-1-o.rempel@pengutronix.de> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: ore@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-kernel@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Handle under-voltage events for crucial regulators to maintain system stability and avoid issues during power drops. Signed-off-by: Oleksij Rempel --- drivers/regulator/core.c | 38 +++++++++++++++++++++++++++++++ drivers/regulator/of_regulator.c | 2 ++ include/linux/regulator/machine.h | 10 ++++++++ 3 files changed, 50 insertions(+) diff --git a/drivers/regulator/core.c b/drivers/regulator/core.c index 3137e40fcd3e..a072f721f288 100644 --- a/drivers/regulator/core.c +++ b/drivers/regulator/core.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -5061,6 +5062,41 @@ void regulator_bulk_free(int num_consumers, } EXPORT_SYMBOL_GPL(regulator_bulk_free); =20 +/** + * regulator_handle_critical - Handle events for system-critical regulator= s. + * @rdev: The regulator device. + * @event: The event being handled. + * + * This function handles critical events such as under-voltage, over-curre= nt, + * and unknown errors for regulators deemed system-critical. On detecting = such + * events, it triggers a hardware protection shutdown with a defined timeo= ut. + */ +static void regulator_handle_critical(struct regulator_dev *rdev, + unsigned long event) +{ + const char *reason =3D NULL; + + if (!rdev->constraints->system_critical) + return; + + switch (event) { + case REGULATOR_EVENT_UNDER_VOLTAGE: + reason =3D "System critical regulator: voltage drop detected"; + break; + case REGULATOR_EVENT_OVER_CURRENT: + reason =3D "System critical regulator: over-current detected"; + break; + case REGULATOR_EVENT_FAIL: + reason =3D "System critical regulator: unknown error"; + } + + if (!reason) + return; + + hw_protection_shutdown(reason, + REGULATOR_DEF_UV_LESS_CRITICAL_WINDOW_MS); +} + /** * regulator_notifier_call_chain - call regulator event notifier * @rdev: regulator source @@ -5073,6 +5109,8 @@ EXPORT_SYMBOL_GPL(regulator_bulk_free); int regulator_notifier_call_chain(struct regulator_dev *rdev, unsigned long event, void *data) { + regulator_handle_critical(rdev, event); + _notifier_call_chain(rdev, event, data); return NOTIFY_DONE; =20 diff --git a/drivers/regulator/of_regulator.c b/drivers/regulator/of_regula= tor.c index 1b65e5e4e40f..3bdd6f1919a4 100644 --- a/drivers/regulator/of_regulator.c +++ b/drivers/regulator/of_regulator.c @@ -131,6 +131,8 @@ static int of_get_regulation_constraints(struct device = *dev, constraints->valid_ops_mask |=3D REGULATOR_CHANGE_STATUS; =20 constraints->pull_down =3D of_property_read_bool(np, "regulator-pull-down= "); + constraints->system_critical =3D of_property_read_bool(np, + "system-critical-regulator"); =20 if (of_property_read_bool(np, "regulator-allow-bypass")) constraints->valid_ops_mask |=3D REGULATOR_CHANGE_BYPASS; diff --git a/include/linux/regulator/machine.h b/include/linux/regulator/ma= chine.h index 621b7f4a3639..e0ddfb5593c9 100644 --- a/include/linux/regulator/machine.h +++ b/include/linux/regulator/machine.h @@ -49,6 +49,13 @@ struct regulator; #define DISABLE_IN_SUSPEND 1 #define ENABLE_IN_SUSPEND 2 =20 +/* + * Default time window (in milliseconds) following a critical under-voltage + * event during which less critical actions can be safely carried out by t= he + * system. + */ +#define REGULATOR_DEF_UV_LESS_CRITICAL_WINDOW_MS 10 + /* Regulator active discharge flags */ enum regulator_active_discharge { REGULATOR_ACTIVE_DISCHARGE_DEFAULT, @@ -127,6 +134,8 @@ struct notification_limit { * @ramp_disable: Disable ramp delay when initialising or when setting vol= tage. * @soft_start: Enable soft start so that voltage ramps slowly. * @pull_down: Enable pull down when regulator is disabled. + * @system_critical: Set if the regulator is critical to system stability = or + * functionality. * @over_current_protection: Auto disable on over current event. * * @over_current_detection: Configure over current limits. @@ -214,6 +223,7 @@ struct regulation_constraints { unsigned ramp_disable:1; /* disable ramp delay */ unsigned soft_start:1; /* ramp voltage slowly */ unsigned pull_down:1; /* pull down resistor when regulator off */ + unsigned system_critical:1; /* critical to system stability */ unsigned over_current_protection:1; /* auto disable on over current */ unsigned over_current_detection:1; /* notify on over current */ unsigned over_voltage_detection:1; /* notify on over voltage */ --=20 2.39.2