From nobody Thu Dec 25 13:09:00 2025 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 664831E48F for ; Fri, 19 Jan 2024 13:25:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705670739; cv=none; b=YwBARdLhWucBHpeYZvSISkmvtLEUCIZpVLj/sFczdsWNlCtVIiIsgRbYlJclb2/uTINhQt0ryn4rGMDhe5FUWfE7UpiRHCpu5f0p5hBR4P9sZxCULZTjil1z3lalSL7PYkh61qPhHR3RmE7mutnM3gHKRVUQ1Rco7xQ3odfu/f4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1705670739; c=relaxed/simple; bh=C3KOqcCPboHE8CVljWUDfdheWimD/KSO18sHrtBids4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=gzZkw+WXm4Bnb4+pPKmELXXZy1ud0MPAaXlgv7jvjsPXDc16MIvXhaAkqoHrhw/z37C4q0/aHZzPz+pYstTZ6M/dhmYWoQScd64VL79bsV1P4kUt8jzOJQ2tflEc1xmgx8i835Vkv4Oa/dB+k3sinm82NUS15UhaFiLL6NECExs= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de 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 1rQos7-00074J-C2; Fri, 19 Jan 2024 14:25:23 +0100 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 1rQos6-000viN-8m; Fri, 19 Jan 2024 14:25:22 +0100 Received: from ore by dude04.red.stw.pengutronix.de with local (Exim 4.96) (envelope-from ) id 1rQos6-00F98M-0b; Fri, 19 Jan 2024 14:25:22 +0100 From: Oleksij Rempel To: Sebastian Reichel , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Srinivas Kandagatla Cc: Oleksij Rempel , kernel@pengutronix.de, linux-kernel@vger.kernel.org, Liam Girdwood , Mark Brown , "Rafael J. Wysocki" , Daniel Lezcano , Zhang Rui , Lukasz Luba , linux-pm@vger.kernel.org, devicetree@vger.kernel.org, =?UTF-8?q?S=C3=B8ren=20Andersen?= Subject: [RFC PATCH v1 5/7] power: reset: add PSCR NVMEM Driver for Storing Power State Change Reasons Date: Fri, 19 Jan 2024 14:25:19 +0100 Message-Id: <20240119132521.3609945-6-o.rempel@pengutronix.de> X-Mailer: git-send-email 2.39.2 In-Reply-To: <20240119132521.3609945-1-o.rempel@pengutronix.de> References: <20240119132521.3609945-1-o.rempel@pengutronix.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 Content-Type: text/plain; charset="utf-8" This driver utilizes the Power State Change Reasons (PSCR) framework to store specific power state change information, such as shutdown or reboot reasons, into a designated non-volatile memory (NVMEM) cell. Signed-off-by: Oleksij Rempel --- drivers/power/reset/Kconfig | 11 ++++ drivers/power/reset/Makefile | 1 + drivers/power/reset/pscr-nvmem.c | 100 +++++++++++++++++++++++++++++++ 3 files changed, 112 insertions(+) create mode 100644 drivers/power/reset/pscr-nvmem.c diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig index da76e84302b9..a110dff599af 100644 --- a/drivers/power/reset/Kconfig +++ b/drivers/power/reset/Kconfig @@ -324,3 +324,14 @@ menuconfig PSCR timeouts. =20 If unsure, say N. + +if PSCR + +config PSCR_NVMEM + tristate "Generic NVMEM-based Power State Change Reason Tracking" + depends on OF + help + Enabling this option adds support for storing power state change + reasons in a NVMEM cell. + +endif diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile index d9d744302c68..e7985d81ac8a 100644 --- a/drivers/power/reset/Makefile +++ b/drivers/power/reset/Makefile @@ -32,6 +32,7 @@ obj-$(CONFIG_POWER_RESET_SYSCON) +=3D syscon-reboot.o obj-$(CONFIG_POWER_RESET_SYSCON_POWEROFF) +=3D syscon-poweroff.o obj-$(CONFIG_POWER_RESET_RMOBILE) +=3D rmobile-reset.o obj-$(CONFIG_PSCR) +=3D pscr.o +obj-$(CONFIG_PSCR_NVMEM) +=3D pscr-nvmem.o obj-$(CONFIG_REBOOT_MODE) +=3D reboot-mode.o obj-$(CONFIG_SYSCON_REBOOT_MODE) +=3D syscon-reboot-mode.o obj-$(CONFIG_POWER_RESET_SC27XX) +=3D sc27xx-poweroff.o diff --git a/drivers/power/reset/pscr-nvmem.c b/drivers/power/reset/pscr-nv= mem.c new file mode 100644 index 000000000000..74048341b7d7 --- /dev/null +++ b/drivers/power/reset/pscr-nvmem.c @@ -0,0 +1,100 @@ +// SPDX-License-Identifier: GPL-2.0 +// Copyright (c) Vaisala Oyj. All rights reserved. +// Copyright (c) 2024 Pengutronix, Oleksij Rempel +/* + * Based on drivers/power/reset/nvmem-reboot-mode.c + * Copyright (c) Vaisala Oyj. All rights reserved. + */ + +#include +#include +#include +#include +#include +#include +#include + +struct pscr_nvmem { + struct pscr_driver pscr_drv; + struct nvmem_cell *cell; + size_t max_magic_bytes; +}; + +static int pscr_nvmem_write(struct pscr_driver *pscr_drv, u32 magic) +{ + struct pscr_nvmem *priv =3D container_of(pscr_drv, struct pscr_nvmem, + pscr_drv); + size_t size =3D min(priv->max_magic_bytes, sizeof(magic)); + int ret; + + ret =3D nvmem_cell_write(priv->cell, &magic, size); + if (ret < 0) + dev_err(pscr_drv->dev, "update reason bits failed: %pe\n", + ERR_PTR(ret)); + + return ret; +} + +static int pscr_nvmem_probe(struct platform_device *pdev) +{ + const char *pscr =3D "pscr"; + struct pscr_nvmem *priv; + size_t bytes, bits, magic_bits; + int ret; + + priv =3D devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + priv->pscr_drv.dev =3D &pdev->dev; + priv->pscr_drv.write =3D pscr_nvmem_write; + + priv->cell =3D devm_nvmem_cell_get(&pdev->dev, pscr); + if (IS_ERR(priv->cell)) + return dev_err_probe(&pdev->dev, PTR_ERR(priv->cell), + "failed to get the nvmem %s cell\n", pscr); + + ret =3D nvmem_cell_get_size(priv->cell, &bytes, &bits); + if (ret < 0) + return dev_err_probe(&pdev->dev, ret, "failed to get the nvmem %s size\n= ", + pscr); + + if (!bytes || bytes > sizeof(u32) || bits > 32) + return dev_err_probe(&pdev->dev, -EINVAL, "invalid nvmem %s size. bytes:= %zu, bits: %zu\n", + pscr, bytes, bits); + + ret =3D devm_pscr_register(&pdev->dev, &priv->pscr_drv); + if (ret) + return dev_err_probe(&pdev->dev, ret, "failed to register pscr driver\n"= ); + + magic_bits =3D fls(priv->pscr_drv.max_magic); + priv->max_magic_bytes =3D DIV_ROUND_UP(magic_bits, 8); + + if (!bits) + bits =3D bytes * 8; + + if (magic_bits > bits) + return dev_err_probe(&pdev->dev, -EINVAL, "provided magic can't fit into= nvmem %s. bytes: %zu, bits: %zu, magic_bits: %zu\n", + pscr, bytes, bits, magic_bits);=20 + + return ret; +} + +static const struct of_device_id pscr_nvmem_of_match[] =3D { + { .compatible =3D "pscr-nvmem" }, + {} +}; +MODULE_DEVICE_TABLE(of, pscr_nvmem_of_match); + +static struct platform_driver pscr_nvmem_driver =3D { + .probe =3D pscr_nvmem_probe, + .driver =3D { + .name =3D "pscr-nvmem", + .of_match_table =3D pscr_nvmem_of_match, + }, +}; +module_platform_driver(pscr_nvmem_driver); + +MODULE_AUTHOR("Oleksij Rempel "); +MODULE_DESCRIPTION("NVMEM Driver for Power State Change Reason Tracking"); +MODULE_LICENSE("GPL v2"); --=20 2.39.2