From patchwork Wed Apr 27 13:55:31 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jean-Jacques Hiblot X-Patchwork-Id: 567441 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 77169C433F5 for ; Wed, 27 Apr 2022 13:56:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237070AbiD0N7Z (ORCPT ); Wed, 27 Apr 2022 09:59:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:32768 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S236876AbiD0N7M (ORCPT ); Wed, 27 Apr 2022 09:59:12 -0400 Received: from smtpout1.mo3004.mail-out.ovh.net (smtpout1.mo3004.mail-out.ovh.net [79.137.123.219]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 682291F638; Wed, 27 Apr 2022 06:56:00 -0700 (PDT) Received: from pro2.mail.ovh.net (unknown [10.109.156.240]) by mo3004.mail-out.ovh.net (Postfix) with ESMTPS id 666E923F6EA; Wed, 27 Apr 2022 13:55:58 +0000 (UTC) Received: from localhost.localdomain (88.125.132.16) by DAG1EX2.emp2.local (172.16.2.2) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2375.24; Wed, 27 Apr 2022 15:55:57 +0200 From: Jean-Jacques Hiblot To: , , , , CC: , , Phil Edworthy , Jean-Jacques Hiblot Subject: [PATCH v7 2/2] watchdog: Add Renesas RZ/N1 Watchdog driver Date: Wed, 27 Apr 2022 15:55:31 +0200 Message-ID: <20220427135531.708279-3-jjhiblot@traphandler.com> X-Mailer: git-send-email 2.25.1 In-Reply-To: <20220427135531.708279-1-jjhiblot@traphandler.com> References: <20220427135531.708279-1-jjhiblot@traphandler.com> MIME-Version: 1.0 X-Originating-IP: [88.125.132.16] X-ClientProxiedBy: DAG8EX1.emp2.local (172.16.2.81) To DAG1EX2.emp2.local (172.16.2.2) X-Ovh-Tracer-Id: 5435281803563973109 X-VR-SPAMSTATE: OK X-VR-SPAMSCORE: -100 X-VR-SPAMCAUSE: gggruggvucftvghtrhhoucdtuddrgedvfedrudehgdeijecutefuodetggdotefrodftvfcurfhrohhfihhlvgemucfqggfjpdevjffgvefmvefgnecuuegrihhlohhuthemucehtddtnecusecvtfgvtghiphhivghnthhsucdlqddutddtmdenucfjughrpefhvfevufffkffojghfggfgtghisehtkeertdertddtnecuhfhrohhmpeflvggrnhdqlfgrtghquhgvshcujfhisghlohhtuceojhhjhhhisghlohhtsehtrhgrphhhrghnughlvghrrdgtohhmqeenucggtffrrghtthgvrhhnpeduteevleevvefggfdvueffffejhfehheeuiedtgedtjeeghfehueduudegfeefueenucfkpheptddrtddrtddrtddpkeekrdduvdehrddufedvrdduieenucevlhhushhtvghrufhiiigvpedtnecurfgrrhgrmhepmhhouggvpehsmhhtphhouhhtpdhhvghlohepphhrohdvrdhmrghilhdrohhvhhdrnhgvthdpihhnvghtpedtrddtrddtrddtpdhmrghilhhfrhhomhepjhhjhhhisghlohhtsehtrhgrphhhrghnughlvghrrdgtohhmpdhnsggprhgtphhtthhopedupdhrtghpthhtohepphhhihhlrdgvugifohhrthhhhiesrhgvnhgvshgrshdrtghomh Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Phil Edworthy This is a driver for the standard WDT on the RZ/N1 devices. This WDT has very limited timeout capabilities. However, it can reset the device. To do so, the corresponding bits in the SysCtrl RSTEN register need to be enabled. This is not done by this driver. Signed-off-by: Phil Edworthy Signed-off-by: Jean-Jacques Hiblot Reviewed-by: Tzung-Bi Shih Reviewed-by: Guenter Roeck --- drivers/watchdog/Kconfig | 8 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/rzn1_wdt.c | 203 ++++++++++++++++++++++++++++++++++++ 3 files changed, 212 insertions(+) create mode 100644 drivers/watchdog/rzn1_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index c4e82a8d863f..4d5e503c8950 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -883,6 +883,14 @@ config RENESAS_RZAWDT This driver adds watchdog support for the integrated watchdogs in the Renesas RZ/A SoCs. These watchdogs can be used to reset a system. +config RENESAS_RZN1WDT + tristate "Renesas RZ/N1 watchdog" + depends on ARCH_RENESAS || COMPILE_TEST + select WATCHDOG_CORE + help + This driver adds watchdog support for the integrated watchdogs in the + Renesas RZ/N1 SoCs. These watchdogs can be used to reset a system. + config RENESAS_RZG2LWDT tristate "Renesas RZ/G2L WDT Watchdog" depends on ARCH_RENESAS || COMPILE_TEST diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index f7da867e8782..38d38564f47b 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -84,6 +84,7 @@ obj-$(CONFIG_LPC18XX_WATCHDOG) += lpc18xx_wdt.o obj-$(CONFIG_BCM7038_WDT) += bcm7038_wdt.o obj-$(CONFIG_RENESAS_WDT) += renesas_wdt.o obj-$(CONFIG_RENESAS_RZAWDT) += rza_wdt.o +obj-$(CONFIG_RENESAS_RZN1WDT) += rzn1_wdt.o obj-$(CONFIG_RENESAS_RZG2LWDT) += rzg2l_wdt.o obj-$(CONFIG_ASPEED_WATCHDOG) += aspeed_wdt.o obj-$(CONFIG_STM32_WATCHDOG) += stm32_iwdg.o diff --git a/drivers/watchdog/rzn1_wdt.c b/drivers/watchdog/rzn1_wdt.c new file mode 100644 index 000000000000..55ab384b9965 --- /dev/null +++ b/drivers/watchdog/rzn1_wdt.c @@ -0,0 +1,203 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Renesas RZ/N1 Watchdog timer. + * This is a 12-bit timer driver from a (62.5/16384) MHz clock. It can't even + * cope with 2 seconds. + * + * Copyright 2018 Renesas Electronics Europe Ltd. + * + * Derived from Ralink RT288x watchdog timer. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DEFAULT_TIMEOUT 60 + +#define RZN1_WDT_RETRIGGER 0x0 +#define RZN1_WDT_RETRIGGER_RELOAD_VAL 0 +#define RZN1_WDT_RETRIGGER_RELOAD_VAL_MASK 0xfff +#define RZN1_WDT_RETRIGGER_PRESCALE BIT(12) +#define RZN1_WDT_RETRIGGER_ENABLE BIT(13) +#define RZN1_WDT_RETRIGGER_WDSI (0x2 << 14) + +#define RZN1_WDT_PRESCALER 16384 +#define RZN1_WDT_MAX 4095 + +struct rzn1_watchdog { + struct watchdog_device wdtdev; + void __iomem *base; + unsigned long clk_rate_khz; +}; + +static inline uint32_t max_heart_beat_ms(unsigned long clk_rate_khz) +{ + return (RZN1_WDT_MAX * RZN1_WDT_PRESCALER) / clk_rate_khz; +} + +static inline uint32_t compute_reload_value(uint32_t tick_ms, + unsigned long clk_rate_khz) +{ + return (tick_ms * clk_rate_khz) / RZN1_WDT_PRESCALER; +} + +static int rzn1_wdt_ping(struct watchdog_device *w) +{ + struct rzn1_watchdog *wdt = watchdog_get_drvdata(w); + + /* Any value retrigggers the watchdog */ + writel(0, wdt->base + RZN1_WDT_RETRIGGER); + + return 0; +} + +static int rzn1_wdt_start(struct watchdog_device *w) +{ + struct rzn1_watchdog *wdt = watchdog_get_drvdata(w); + u32 val; + + /* + * The hardware allows you to write to this reg only once. + * Since this includes the reload value, there is no way to change the + * timeout once started. Also note that the WDT clock is half the bus + * fabric clock rate, so if the bus fabric clock rate is changed after + * the WDT is started, the WDT interval will be wrong. + */ + val = RZN1_WDT_RETRIGGER_WDSI; + val |= RZN1_WDT_RETRIGGER_ENABLE; + val |= RZN1_WDT_RETRIGGER_PRESCALE; + val |= compute_reload_value(w->max_hw_heartbeat_ms, wdt->clk_rate_khz); + writel(val, wdt->base + RZN1_WDT_RETRIGGER); + + return 0; +} + +static irqreturn_t rzn1_wdt_irq(int irq, void *_wdt) +{ + pr_crit("RZN1 Watchdog. Initiating system reboot\n"); + emergency_restart(); + + return IRQ_HANDLED; +} + +static struct watchdog_info rzn1_wdt_info = { + .identity = "RZ/N1 Watchdog", + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, +}; + +static const struct watchdog_ops rzn1_wdt_ops = { + .owner = THIS_MODULE, + .start = rzn1_wdt_start, + .ping = rzn1_wdt_ping, +}; + +static void rzn1_wdt_clk_disable_unprepare(void *data) +{ + clk_disable_unprepare(data); +} + +static int rzn1_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct rzn1_watchdog *wdt; + struct device_node *np = dev->of_node; + struct clk *clk; + unsigned long clk_rate; + int ret; + int irq; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) + return -ENOMEM; + + wdt->base = devm_platform_ioremap_resource(pdev, 0); + if (IS_ERR(wdt->base)) + return PTR_ERR(wdt->base); + + irq = platform_get_irq(pdev, 0); + if (irq < 0) + return irq; + + ret = devm_request_irq(dev, irq, rzn1_wdt_irq, 0, + np->name, wdt); + if (ret) { + dev_err(dev, "failed to request irq %d\n", irq); + return ret; + } + + clk = devm_clk_get(dev, NULL); + if (IS_ERR(clk)) { + dev_err(dev, "failed to get the clock\n"); + return PTR_ERR(clk); + } + + ret = clk_prepare_enable(clk); + if (ret) { + dev_err(dev, "failed to prepare/enable the clock\n"); + return ret; + } + + ret = devm_add_action_or_reset(dev, rzn1_wdt_clk_disable_unprepare, + clk); + if (ret) + return ret; + + clk_rate = clk_get_rate(clk); + if (!clk_rate) { + dev_err(dev, "failed to get the clock rate\n"); + return -EINVAL; + } + + wdt->clk_rate_khz = clk_rate / 1000; + wdt->wdtdev.info = &rzn1_wdt_info, + wdt->wdtdev.ops = &rzn1_wdt_ops, + wdt->wdtdev.status = WATCHDOG_NOWAYOUT_INIT_STATUS, + wdt->wdtdev.parent = dev; + /* + * The period of the watchdog cannot be changed once set + * and is limited to a very short period. + * Configure it for a 1s period once and for all, and + * rely on the heart-beat provided by the watchdog core + * to make this usable by the user-space. + */ + wdt->wdtdev.max_hw_heartbeat_ms = max_heart_beat_ms(wdt->clk_rate_khz); + if (wdt->wdtdev.max_hw_heartbeat_ms > 1000) + wdt->wdtdev.max_hw_heartbeat_ms = 1000; + + wdt->wdtdev.timeout = DEFAULT_TIMEOUT; + ret = watchdog_init_timeout(&wdt->wdtdev, 0, dev); + if (ret) + return ret; + + watchdog_set_drvdata(&wdt->wdtdev, wdt); + + return devm_watchdog_register_device(dev, &wdt->wdtdev); +} + + +static const struct of_device_id rzn1_wdt_match[] = { + { .compatible = "renesas,rzn1-wdt" }, + {}, +}; +MODULE_DEVICE_TABLE(of, rzn1_wdt_match); + +static struct platform_driver rzn1_wdt_driver = { + .probe = rzn1_wdt_probe, + .driver = { + .name = KBUILD_MODNAME, + .of_match_table = rzn1_wdt_match, + }, +}; + +module_platform_driver(rzn1_wdt_driver); + +MODULE_DESCRIPTION("Renesas RZ/N1 hardware watchdog"); +MODULE_AUTHOR("Phil Edworthy "); +MODULE_LICENSE("GPL");