From patchwork Fri Apr 3 05:29:00 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Benn X-Patchwork-Id: 11471829 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 8AFB714DD for ; Fri, 3 Apr 2020 05:29:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5604C20B1F for ; Fri, 3 Apr 2020 05:29:47 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="kUKOiWpA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2387784AbgDCF3q (ORCPT ); Fri, 3 Apr 2020 01:29:46 -0400 Received: from mail-pg1-f193.google.com ([209.85.215.193]:39653 "EHLO mail-pg1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387526AbgDCF3q (ORCPT ); Fri, 3 Apr 2020 01:29:46 -0400 Received: by mail-pg1-f193.google.com with SMTP id g32so2984796pgb.6 for ; Thu, 02 Apr 2020 22:29:45 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=chromium.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=IOQ4VkXOlVBsS6AzreYmGymNEVK3siv1or7MyGGQVX8=; b=kUKOiWpA3TIGUUOBf+V9dnf5HdXryMdctV3Rr3d12wkarso1RyRmeEyi5QmvymvQS0 rBvsk4g9TDCV3wIXHXpTrvjwLqTkgaPSlY9NjHCDBwoW4ttjJp2EeKiQPIBXWMEpETRe MSwoxXpe2DMmMvluxmDVVhaKIWef4ObpuZ/Kc= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=IOQ4VkXOlVBsS6AzreYmGymNEVK3siv1or7MyGGQVX8=; b=PrqxvX2TNbAObweWhpw7nY9C3HRp817VtN67Lbrh/9iHEY2eOb0EIzrK83z27q5qL+ XX34tr21mDdMCjhXaj5h1g2UKLdbXyAoni0Bh0NauXJ0rMuD8xDgJ/4mbnFVf2EZpYhN Afxd3fsJEGplsaVRU1rtxIahVvxUWZIYvzx8TtmM+FprrCXxWwElhG3XRjXkJS3XBSF6 nzqlLHtOI1xKZpMu6XmxoL4c0HqKVmjD77ogKsn4A49KX4R7YeL4Koo49QWIqIf9Q2jd dKxr5rYKCn4ealT2/V8YpLW8eDDjBRVx3QYbo+aDo6mWuSfHwguD5Mpmj0ZCluEum8O0 9nzA== X-Gm-Message-State: AGi0PuZtBdizgz5DmqzhjgYJlnuH9sFChe08FONvgRlYXdARPHaIyL7H Q7HyYO+w5H9MBWkBTAWKoC5Svg== X-Google-Smtp-Source: APiQypJQcxlAo0WAx64joAbtIcVTCkL01eab8EGORvPmpQeFKKY7MDtevBA32CimWeqlV3+AQxbc7g== X-Received: by 2002:a63:e210:: with SMTP id q16mr6481381pgh.26.1585891785270; Thu, 02 Apr 2020 22:29:45 -0700 (PDT) Received: from localhost ([2401:fa00:9:14:1105:3e8a:838d:e326]) by smtp.gmail.com with ESMTPSA id p9sm4496022pgs.50.2020.04.02.22.29.37 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 02 Apr 2020 22:29:44 -0700 (PDT) From: Evan Benn To: LKML Cc: xingyu.chen@amlogic.com, jwerner@chromium.org, Evan Benn , Andy Shevchenko , Anson Huang , Bjorn Andersson , Catalin Marinas , "David S. Miller" , Greg Kroah-Hartman , Guenter Roeck , Jonathan Cameron , Leonard Crestez , Manivannan Sadhasivam , Marcin Juszkiewicz , Matthias Brugger , Mauro Carvalho Chehab , Olof Johansson , Rob Herring , Shawn Guo , Valentin Schneider , Vinod Koul , Will Deacon , Wim Van Sebroeck , linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-watchdog@vger.kernel.org Subject: [PATCH v2 2/2] watchdog: Add new arm_smd_wdt watchdog driver Date: Fri, 3 Apr 2020 16:29:00 +1100 Message-Id: <20200403162742.v2.2.Ia92bb4d4ce84bcefeba1d00aaa1c1e919b6164ef@changeid> X-Mailer: git-send-email 2.26.0.292.g33ef6b2f38-goog In-Reply-To: <20200403052900.258855-1-evanbenn@chromium.org> References: <20200403052900.258855-1-evanbenn@chromium.org> MIME-Version: 1.0 Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Julius Werner This patch adds a watchdog driver that can be used on ARM systems with the appropriate watchdog implemented in Secure Monitor firmware. The driver communicates with firmware via a Secure Monitor Call. This may be useful for platforms using TrustZone that want the Secure Monitor firmware to have the final control over the watchdog. This is implemented on mt8173 chromebook devices oak, elm and hana in arm trusted firmware file plat/mediatek/mt8173/drivers/wdt/wdt.c. Signed-off-by: Julius Werner Signed-off-by: Evan Benn Reviewed-by: Guenter Roeck --- Changes in v3: - Add optional get_timeleft op - change name to arm_smc_wdt Changes in v2: - use watchdog_stop_on_reboot - use watchdog_stop_on_unregister - use devm_watchdog_register_device - remove smcwd_shutdown, smcwd_remove - change error codes MAINTAINERS | 1 + arch/arm64/configs/defconfig | 1 + drivers/watchdog/Kconfig | 13 +++ drivers/watchdog/Makefile | 1 + drivers/watchdog/arm_smc_wdt.c | 181 +++++++++++++++++++++++++++++++++ 5 files changed, 197 insertions(+) create mode 100644 drivers/watchdog/arm_smc_wdt.c diff --git a/MAINTAINERS b/MAINTAINERS index af8842b998a93..2ec83d4c1032f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1426,6 +1426,7 @@ M: Julius Werner R: Evan Benn S: Maintained F: devicetree/bindings/watchdog/arm-smc-wdt.yaml +F: drivers/watchdog/arm_smc_wdt.c ARM SMMU DRIVERS M: Will Deacon diff --git a/arch/arm64/configs/defconfig b/arch/arm64/configs/defconfig index 4db223dbc5499..b5117d46c1d96 100644 --- a/arch/arm64/configs/defconfig +++ b/arch/arm64/configs/defconfig @@ -467,6 +467,7 @@ CONFIG_QCOM_SPMI_TEMP_ALARM=m CONFIG_UNIPHIER_THERMAL=y CONFIG_WATCHDOG=y CONFIG_ARM_SP805_WATCHDOG=y +CONFIG_ARM_SMC_WATCHDOG=y CONFIG_S3C2410_WATCHDOG=y CONFIG_DW_WATCHDOG=y CONFIG_SUNXI_WATCHDOG=m diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 9ea2b43d4b012..2a44af10d9beb 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -859,6 +859,19 @@ config DIGICOLOR_WATCHDOG To compile this driver as a module, choose M here: the module will be called digicolor_wdt. +config ARM_SMC_WATCHDOG + tristate "ARM Secure Monitor Call based watchdog support" + depends on ARM || ARM64 + depends on OF + depends on HAVE_ARM_SMCCC + select WATCHDOG_CORE + help + Say Y here to include support for a watchdog timer + implemented by the EL3 Secure Monitor on ARM platforms. + Requires firmware support. + To compile this driver as a module, choose M here: the + module will be called arm_smc_wdt. + config LPC18XX_WATCHDOG tristate "LPC18xx/43xx Watchdog" depends on ARCH_LPC18XX || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 2ee352bf3372d..ec9d4337dad70 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -93,6 +93,7 @@ obj-$(CONFIG_UNIPHIER_WATCHDOG) += uniphier_wdt.o obj-$(CONFIG_RTD119X_WATCHDOG) += rtd119x_wdt.o obj-$(CONFIG_SPRD_WATCHDOG) += sprd_wdt.o obj-$(CONFIG_PM8916_WATCHDOG) += pm8916_wdt.o +obj-$(CONFIG_ARM_SMC_WATCHDOG) += arm_smc_wdt.o # X86 (i386 + ia64 + x86_64) Architecture obj-$(CONFIG_ACQUIRE_WDT) += acquirewdt.o diff --git a/drivers/watchdog/arm_smc_wdt.c b/drivers/watchdog/arm_smc_wdt.c new file mode 100644 index 0000000000000..468995f776b3c --- /dev/null +++ b/drivers/watchdog/arm_smc_wdt.c @@ -0,0 +1,181 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * ARM Secure Monitor Call watchdog driver + * + * Copyright 2020 Google LLC. + * Julius Werner + * Based on mtk_wdt.c + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "arm_smc_wdt" +#define DRV_VERSION "1.0" + +#define SMCWD_FUNC_ID 0x82003d06 + +enum smcwd_call { + SMCWD_INIT = 0, + SMCWD_SET_TIMEOUT = 1, + SMCWD_ENABLE = 2, + SMCWD_PET = 3, + SMCWD_GET_TIMELEFT = 4, +}; + +static bool nowayout = WATCHDOG_NOWAYOUT; +static unsigned int timeout; + +static int smcwd_call(enum smcwd_call call, unsigned long arg, + struct arm_smccc_res *res) +{ + struct arm_smccc_res local_res; + + if (!res) + res = &local_res; + + arm_smccc_smc(SMCWD_FUNC_ID, call, arg, 0, 0, 0, 0, 0, res); + + if (res->a0 == PSCI_RET_NOT_SUPPORTED) + return -ENODEV; + if (res->a0 == PSCI_RET_INVALID_PARAMS) + return -EINVAL; + if (res->a0 != PSCI_RET_SUCCESS) + return -EIO; + return 0; +} + +static int smcwd_ping(struct watchdog_device *wdd) +{ + return smcwd_call(SMCWD_PET, 0, NULL); +} + +static unsigned int smcwd_get_timeleft(struct watchdog_device *wdd) +{ + struct arm_smccc_res res; + + smcwd_call(SMCWD_GET_TIMELEFT, 0, &res); + return res.a0; +} + +static int smcwd_set_timeout(struct watchdog_device *wdd, unsigned int timeout) +{ + int res; + + res = smcwd_call(SMCWD_SET_TIMEOUT, timeout, NULL); + if (!res) + wdd->timeout = timeout; + return res; +} + +static int smcwd_stop(struct watchdog_device *wdd) +{ + return smcwd_call(SMCWD_ENABLE, 0, NULL); +} + +static int smcwd_start(struct watchdog_device *wdd) +{ + return smcwd_call(SMCWD_ENABLE, 1, NULL); +} + +static const struct watchdog_info smcwd_info = { + .identity = DRV_NAME, + .options = WDIOF_SETTIMEOUT | + WDIOF_KEEPALIVEPING | + WDIOF_MAGICCLOSE, +}; + +static const struct watchdog_ops smcwd_ops = { + .start = smcwd_start, + .stop = smcwd_stop, + .ping = smcwd_ping, + .set_timeout = smcwd_set_timeout, +}; + +static const struct watchdog_ops smcwd_timeleft_ops = { + .start = smcwd_start, + .stop = smcwd_stop, + .ping = smcwd_ping, + .set_timeout = smcwd_set_timeout, + .get_timeleft = smcwd_get_timeleft, +}; + +static int smcwd_probe(struct platform_device *pdev) +{ + struct watchdog_device *wdd; + int err; + struct arm_smccc_res res; + + err = smcwd_call(SMCWD_INIT, 0, &res); + if (err < 0) + return err; + + wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL); + if (!wdd) + return -ENOMEM; + + platform_set_drvdata(pdev, wdd); + + wdd->info = &smcwd_info; + /* get_timeleft is optional */ + if (smcwd_call(SMCWD_GET_TIMELEFT, 0, NULL)) + wdd->ops = &smcwd_ops; + else + wdd->ops = &smcwd_timeleft_ops; + wdd->timeout = res.a2; + wdd->max_timeout = res.a2; + wdd->min_timeout = res.a1; + wdd->parent = &pdev->dev; + + watchdog_stop_on_reboot(wdd); + watchdog_stop_on_unregister(wdd); + watchdog_set_nowayout(wdd, nowayout); + watchdog_init_timeout(wdd, timeout, &pdev->dev); + err = smcwd_set_timeout(wdd, wdd->timeout); + if (err) + return err; + + err = devm_watchdog_register_device(&pdev->dev, wdd); + if (err) + return err; + + dev_info(&pdev->dev, "Watchdog registered (timeout=%d sec, nowayout=%d)\n", + wdd->timeout, nowayout); + + return 0; +} + +static const struct of_device_id smcwd_dt_ids[] = { + { .compatible = "mediatek,mt8173-smc-wdt" }, + {} +}; +MODULE_DEVICE_TABLE(of, smcwd_dt_ids); + +static struct platform_driver smcwd_driver = { + .probe = smcwd_probe, + .driver = { + .name = DRV_NAME, + .of_match_table = smcwd_dt_ids, + }, +}; + +module_platform_driver(smcwd_driver); + +module_param(timeout, uint, 0); +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); + +module_param(nowayout, bool, 0); +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); + +MODULE_LICENSE("GPL"); +MODULE_AUTHOR("Julius Werner "); +MODULE_DESCRIPTION("ARM Secure Monitor Call Watchdog Driver"); +MODULE_VERSION(DRV_VERSION);