From patchwork Thu Apr 23 04:40:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Evan Benn X-Patchwork-Id: 11505003 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 C8DE2912 for ; Thu, 23 Apr 2020 04:41:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A8127214AF for ; Thu, 23 Apr 2020 04:41:09 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=chromium.org header.i=@chromium.org header.b="khp/oGR/" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726374AbgDWElJ (ORCPT ); Thu, 23 Apr 2020 00:41:09 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726358AbgDWElI (ORCPT ); Thu, 23 Apr 2020 00:41:08 -0400 Received: from mail-pf1-x441.google.com (mail-pf1-x441.google.com [IPv6:2607:f8b0:4864:20::441]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7739BC03C1AB for ; Wed, 22 Apr 2020 21:41:08 -0700 (PDT) Received: by mail-pf1-x441.google.com with SMTP id d184so2319513pfd.4 for ; Wed, 22 Apr 2020 21:41:08 -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=neZvYSmnlNni0Tvb9Upl+depscD06FdC/T7+q9W88go=; b=khp/oGR/01tjCHJR9FAzKgTqLxOkhyhJrLYIxNoW1uqawXHuWjAK3+YGS+cpudKFNJ nmll8SwP6tlSiP5HwOfx0/ROTjd0MK5SSosbuqyDTBq6BLMEfvk+WFRJagXfBbKzPKSc tdKLZQgTqTXkhDTJuTXnAohuZo5DHGsolCk9U= 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=neZvYSmnlNni0Tvb9Upl+depscD06FdC/T7+q9W88go=; b=IV8iLg7R81axMwln9rTzAnxQsu2sG55JuxnY8jVckfgKXj2f5PKBNJsvTb2XgpzrU8 EI7KYmFRxRZDgBtsyo3V+1d51LGPFWR5BghXYpjUbQQ/TJwe8w1ZTB1jTwT9h74nafLG JHgu8RiAikaW49EbE9sphk6O2ORRkF6DMADjRxVqfU7mK8FUz3tLsLVUDMSlAA8vw5yl yql23Mn30yx9FIjODSsRpwnxzmOnV7l/EbleK4f9F3MAU0gA6Izg8rBE7/UlVXe0YdoI 2c0bQjyQhqYFLObd9ZGD3//O1A1+mSEAPUXwPA+Up4hAv2tqF/xho4gzMFDx4M5ygAWA EjqA== X-Gm-Message-State: AGi0Pub9AS6rmu8uMwAlrO0D6iLI7jMNY/uscz0XjyEwL1LGNmAXV2g/ BiQrtTfxA4XRF9ID2gMVQ37ug4dkMwg= X-Google-Smtp-Source: APiQypJV1Op/V2nJFwiLrojnBAS+UzKJgYYJGHrz2PD2lunNoBIe75jm/jo9lXnByDLTKnar6dCK/g== X-Received: by 2002:a63:eb15:: with SMTP id t21mr2274211pgh.279.1587616867954; Wed, 22 Apr 2020 21:41:07 -0700 (PDT) Received: from localhost ([2401:fa00:9:14:1105:3e8a:838d:e326]) by smtp.gmail.com with ESMTPSA id r78sm1254705pfr.10.2020.04.22.21.41.00 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 22 Apr 2020 21:41:07 -0700 (PDT) From: Evan Benn To: LKML Cc: jwerner@chromium.org, xingyu.chen@amlogic.com, Evan Benn , Anson Huang , Bjorn Andersson , Catalin Marinas , "David S. Miller" , Geert Uytterhoeven , Greg Kroah-Hartman , Guenter Roeck , Leonard Crestez , Li Yang , Marcin Juszkiewicz , Matthias Brugger , Mauro Carvalho Chehab , Olof Johansson , Rob Herring , Shawn Guo , Valentin Schneider , Will Deacon , Wim Van Sebroeck , linux-arm-kernel@lists.infradead.org, linux-mediatek@lists.infradead.org, linux-watchdog@vger.kernel.org Subject: [PATCH v5 2/2] watchdog: Add new arm_smc_wdt watchdog driver Date: Thu, 23 Apr 2020 14:40:36 +1000 Message-Id: <20200423143945.v5.2.Ia92bb4d4ce84bcefeba1d00aaa1c1e919b6164ef@changeid> X-Mailer: git-send-email 2.26.2.303.gf8c07b1a785-goog In-Reply-To: <20200423044036.234578-1-evanbenn@chromium.org> References: <20200423044036.234578-1-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 --- Changes in v5: - Make timeleft return 0 on error - Use type punning on smc_func_id to save an alloc - Change compatible to arm,smc-wdt Changes in v4: - Get smc-id from of property - Return a1 instead of a0 in timeleft 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 | 189 +++++++++++++++++++++++++++++++++ 5 files changed, 205 insertions(+) create mode 100644 drivers/watchdog/arm_smc_wdt.c diff --git a/MAINTAINERS b/MAINTAINERS index 0f2b39767bfa9..2b782bbff200a 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -1462,6 +1462,7 @@ 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 24e534d850454..0619df80f7575 100644 --- a/arch/arm64/configs/defconfig +++ b/arch/arm64/configs/defconfig @@ -513,6 +513,7 @@ CONFIG_UNIPHIER_THERMAL=y CONFIG_WATCHDOG=y CONFIG_ARM_SP805_WATCHDOG=y CONFIG_ARM_SBSA_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 0663c604bd642..c440b576d23bf 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -867,6 +867,19 @@ 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 6de2e4ceef190..97bed1d3d97cb 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -94,6 +94,7 @@ 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..7e14909bddda2 --- /dev/null +++ b/drivers/watchdog/arm_smc_wdt.c @@ -0,0 +1,189 @@ +// 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" + +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(struct watchdog_device *wdd, 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((u32)(uintptr_t)watchdog_get_drvdata(wdd), 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(wdd, SMCWD_PET, 0, NULL); +} + +static unsigned int smcwd_get_timeleft(struct watchdog_device *wdd) +{ + struct arm_smccc_res res; + + smcwd_call(wdd, SMCWD_GET_TIMELEFT, 0, &res); + if (res.a0) + return 0; + return res.a1; +} + +static int smcwd_set_timeout(struct watchdog_device *wdd, unsigned int timeout) +{ + int res; + + res = smcwd_call(wdd, SMCWD_SET_TIMEOUT, timeout, NULL); + if (!res) + wdd->timeout = timeout; + return res; +} + +static int smcwd_stop(struct watchdog_device *wdd) +{ + return smcwd_call(wdd, SMCWD_ENABLE, 0, NULL); +} + +static int smcwd_start(struct watchdog_device *wdd) +{ + return smcwd_call(wdd, 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; + u32 smc_func_id; + + wdd = devm_kzalloc(&pdev->dev, sizeof(*wdd), GFP_KERNEL); + if (!wdd) + return -ENOMEM; + platform_set_drvdata(pdev, wdd); + + err = of_property_read_u32(pdev->dev.of_node, "arm,smc-id", + &smc_func_id); + if (err < 0) + return err; + watchdog_set_drvdata(wdd, (void *)(uintptr_t)smc_func_id); + + err = smcwd_call(wdd, SMCWD_INIT, 0, &res); + if (err < 0) + return err; + + wdd->info = &smcwd_info; + /* get_timeleft is optional */ + if (smcwd_call(wdd, 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 = "arm,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);