From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1DBDAC2D0E8 for ; Fri, 3 Apr 2020 06:25:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D1F492073B for ; Fri, 3 Apr 2020 06:25:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="vQkna8LB" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388209AbgDCGZO (ORCPT ); Fri, 3 Apr 2020 02:25:14 -0400 Received: from mail-pf1-f194.google.com ([209.85.210.194]:34967 "EHLO mail-pf1-f194.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729423AbgDCGZN (ORCPT ); Fri, 3 Apr 2020 02:25:13 -0400 Received: by mail-pf1-f194.google.com with SMTP id a13so3019779pfa.2; Thu, 02 Apr 2020 23:25:10 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=sender:date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to:user-agent; bh=vi47+JcTrwsCS8utvyF9+t5soTSiBmPKkp7DzEyMUzA=; b=vQkna8LB1mx4qYwnPmNskAv/brGz0rbTLl1+mHeSo+sbsY4joS6CyvhoocDGo0s3df +Fu++Gc5PaXJ/fgLr8K++paGb3pBWpLsHpwRn9YA7RsY1gSW7sqjPzasfThkpwwfBsAU ZlkXrxNSoTkR6UMlzrsFPKqGCudjkthlDHlLDyM70CH8uB/50v93/e7o3RjSYdcVOpzO uzxo0eWRX3jutGDNXzujGKQ6O1eDy1Uns/BLyzGKtTcc2iSFfz3CtABc5L+fwGInC6eU Tk5F4zu/ojxbYxASUuCXXWmnfMO7oC2nsdwYBZGD4xnr/6TELdEaCxW85fopaRQY9Aqe RdZQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:sender:date:from:to:cc:subject:message-id :references:mime-version:content-disposition:in-reply-to:user-agent; bh=vi47+JcTrwsCS8utvyF9+t5soTSiBmPKkp7DzEyMUzA=; b=eCeSJv1xzXC65brPbHcaNEPpYC2+9o0zFuRz1R7WrRSwkfvsgjgic1sIAw6aDH5+cI Nbbrdy+8s049noNzLSgqJC7EUz5nh/hnt8+jPCv+OENF3rc+lQK1i3RORcaTZxoeJiUv ShCkdWniJ5/F4bRnNKZBhl6nCIrEz2lmCd2tRF6J7kqOjQ76G3UyfXA8DBX0EcoQYtxz KtX+mmaufU0uMGvjjoEwKxDfLnewT3hUWvXYbORrqPBZKxCcG0jydouVPrdhmlA7gXI1 QI0JmyRQIX3HjzOr7dRa/FIo3UrEwcMLl3TXkpA4sgP4QnERsQz1Ib2os3LKlvDe+aQq pKJQ== X-Gm-Message-State: AGi0PuaOfobNQwWae4opVbpPwnlMpQp2lgJANUSVMks8j7Liv7eZxuHX zh11kIskj8rZOaqtr0XDay8= X-Google-Smtp-Source: APiQypLpr017bgyWOSDXzSoxGJzl6ChJozJ+0P/OQM1Yu1pkLWcBfZ/VyoAa/AbmmJNivzahvbLvug== X-Received: by 2002:a62:1909:: with SMTP id 9mr6834132pfz.196.1585895110296; Thu, 02 Apr 2020 23:25:10 -0700 (PDT) Received: from localhost ([2600:1700:e321:62f0:329c:23ff:fee3:9d7c]) by smtp.gmail.com with ESMTPSA id 13sm5103254pfn.131.2020.04.02.23.25.09 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Thu, 02 Apr 2020 23:25:09 -0700 (PDT) Date: Thu, 2 Apr 2020 23:25:08 -0700 From: Guenter Roeck To: Michael Walle Cc: linux-gpio@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-hwmon@vger.kernel.org, linux-pwm@vger.kernel.org, linux-watchdog@vger.kernel.org, linux-arm-kernel@lists.infradead.org, Linus Walleij , Bartosz Golaszewski , Rob Herring , Jean Delvare , Lee Jones , Thierry Reding , Uwe =?iso-8859-1?Q?Kleine-K=F6nig?= , Wim Van Sebroeck , Shawn Guo , Li Yang , Thomas Gleixner , Jason Cooper , Marc Zyngier , Mark Brown , Greg Kroah-Hartman Subject: Re: [PATCH v2 08/16] watchdog: add support for sl28cpld watchdog Message-ID: <20200403062508.GA206903@roeck-us.net> References: <20200402203656.27047-1-michael@walle.cc> <20200402203656.27047-9-michael@walle.cc> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200402203656.27047-9-michael@walle.cc> User-Agent: Mutt/1.9.4 (2018-02-28) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Apr 02, 2020 at 10:36:48PM +0200, Michael Walle wrote: > This adds support for the watchdog of the sl28cpld board management > controller. This is part of a multi-function device driver. > > Signed-off-by: Michael Walle > --- > drivers/watchdog/Kconfig | 11 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/sl28cpld_wdt.c | 242 ++++++++++++++++++++++++++++++++ > 3 files changed, 254 insertions(+) > create mode 100644 drivers/watchdog/sl28cpld_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index 0663c604bd64..6c53c1d0f348 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -340,6 +340,17 @@ config MLX_WDT > To compile this driver as a module, choose M here: the > module will be called mlx-wdt. > > +config SL28CPLD_WATCHDOG > + tristate "Kontron sl28 watchdog" > + depends on MFD_SL28CPLD > + select WATCHDOG_CORE > + help > + Say Y here to include support for the watchdog timer > + on the Kontron sl28 CPLD. > + > + To compile this driver as a module, choose M here: the > + module will be called sl28cpld_wdt. > + > # ALPHA Architecture > > # ARM Architecture > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index 6de2e4ceef19..b9ecdf2d7347 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -224,3 +224,4 @@ obj-$(CONFIG_MENF21BMC_WATCHDOG) += menf21bmc_wdt.o > obj-$(CONFIG_MENZ069_WATCHDOG) += menz69_wdt.o > obj-$(CONFIG_RAVE_SP_WATCHDOG) += rave-sp-wdt.o > obj-$(CONFIG_STPMIC1_WATCHDOG) += stpmic1_wdt.o > +obj-$(CONFIG_SL28CPLD_WATCHDOG) += sl28cpld_wdt.o > diff --git a/drivers/watchdog/sl28cpld_wdt.c b/drivers/watchdog/sl28cpld_wdt.c > new file mode 100644 > index 000000000000..79a7e36217a6 > --- /dev/null > +++ b/drivers/watchdog/sl28cpld_wdt.c > @@ -0,0 +1,242 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +/* > + * sl28cpld watchdog driver. > + * > + * Copyright 2019 Kontron Europe GmbH > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > + > +/* > + * Watchdog timer block registers. > + */ > +#define WDT_CTRL 0x00 > +#define WDT_CTRL_EN BIT(0) > +#define WDT_CTRL_LOCK BIT(2) > +#define WDT_CTRL_ASSERT_SYS_RESET BIT(6) > +#define WDT_CTRL_ASSERT_WDT_TIMEOUT BIT(7) > +#define WDT_TIMEOUT 0x01 > +#define WDT_KICK 0x02 > +#define WDT_KICK_VALUE 0x6b > +#define WDT_COUNT 0x03 > + > +static bool nowayout = WATCHDOG_NOWAYOUT; > +module_param(nowayout, bool, 0); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +static int timeout; > +module_param(timeout, int, 0); > +MODULE_PARM_DESC(timeout, "Initial watchdog timeout in seconds"); > + > +struct sl28cpld_wdt { > + struct watchdog_device wdd; > + struct regmap *regmap; > + u32 offset; > + bool assert_wdt_timeout; > +}; > + > +static int sl28cpld_wdt_ping(struct watchdog_device *wdd) > +{ > + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); > + > + return regmap_write(wdt->regmap, wdt->offset + WDT_KICK, > + WDT_KICK_VALUE); > +} > + > +static int sl28cpld_wdt_start(struct watchdog_device *wdd) > +{ > + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); > + unsigned int val; > + > + val = WDT_CTRL_EN | WDT_CTRL_ASSERT_SYS_RESET; > + if (wdt->assert_wdt_timeout) > + val |= WDT_CTRL_ASSERT_WDT_TIMEOUT; > + if (nowayout) > + val |= WDT_CTRL_LOCK; > + > + return regmap_update_bits(wdt->regmap, wdt->offset + WDT_CTRL, > + val, val); > +} > + > +static int sl28cpld_wdt_stop(struct watchdog_device *wdd) > +{ > + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); > + > + return regmap_update_bits(wdt->regmap, wdt->offset + WDT_CTRL, > + WDT_CTRL_EN, 0); > +} > + > +static unsigned int sl28cpld_wdt_status(struct watchdog_device *wdd) > +{ > + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); > + unsigned int status; > + int ret; > + > + ret = regmap_read(wdt->regmap, wdt->offset + WDT_CTRL, &status); > + if (ret < 0) > + return 0; > + > + /* is the watchdog timer running? */ > + return (status & WDT_CTRL_EN) << WDOG_ACTIVE; This is really bad coding style. It uses the fact that WDT_CTRL_EN is at bit position 0 and sets WDOG_ACTIVE accordingly. But that it is wrong, not even considering the coding style problem. The status function is supposed to return WDIOF_ bits. What it returns if the watchdog is running is WDOG_ACTIVE, or BIT(0), which is then reported to userspace as WDIOF_OVERHEAT. > +} > + > +static unsigned int sl28cpld_wdt_get_timeleft(struct watchdog_device *wdd) > +{ > + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); > + int ret; > + unsigned int val; > + > + ret = regmap_read(wdt->regmap, wdt->offset + WDT_COUNT, &val); > + if (ret < 0) > + return 0; > + > + return val; > +} > + > +static int sl28cpld_wdt_set_timeout(struct watchdog_device *wdd, > + unsigned int timeout) > +{ > + int ret; > + struct sl28cpld_wdt *wdt = watchdog_get_drvdata(wdd); Nit: Reverse christmas tree order looks a bit nicer. > + > + ret = regmap_write(wdt->regmap, wdt->offset + WDT_TIMEOUT, timeout); > + if (ret == 0) Please run checkpatch --strict and fix this and the reported alignment problem. > + wdd->timeout = timeout; > + > + return ret; > +} > + > +static const struct watchdog_info sl28cpld_wdt_info = { > + .options = WDIOF_MAGICCLOSE | WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING, > + .identity = "SMARC-sAL28 CPLD watchdog", > +}; > + > +static struct watchdog_ops sl28cpld_wdt_ops = { > + .owner = THIS_MODULE, > + .start = sl28cpld_wdt_start, > + .stop = sl28cpld_wdt_stop, > + .status = sl28cpld_wdt_status, > + .ping = sl28cpld_wdt_ping, > + .set_timeout = sl28cpld_wdt_set_timeout, > + .get_timeleft = sl28cpld_wdt_get_timeleft, > +}; > + > +static int sl28cpld_wdt_locked(struct sl28cpld_wdt *wdt) > +{ > + unsigned int val; > + int ret; > + > + ret = regmap_read(wdt->regmap, wdt->offset + WDT_CTRL, &val); > + if (ret < 0) > + return ret; > + > + return val & WDT_CTRL_LOCK; > +} > + > +static int sl28cpld_wdt_probe(struct platform_device *pdev) > +{ > + struct sl28cpld_wdt *wdt; > + struct watchdog_device *wdd; > + struct resource *res; > + unsigned int val; > + int ret; > + > + if (!pdev->dev.parent) > + return -ENODEV; > + > + wdt = devm_kzalloc(&pdev->dev, sizeof(*wdt), GFP_KERNEL); > + if (!wdt) > + return -ENOMEM; > + > + wdt->regmap = dev_get_regmap(pdev->dev.parent, NULL); > + if (!wdt->regmap) > + return -ENODEV; > + > + res = platform_get_resource(pdev, IORESOURCE_REG, 0); > + if (res == NULL) > + return -EINVAL; > + wdt->offset = res->start; > + > + if (device_property_read_bool(&pdev->dev, > + "kontron,assert-wdt-timeout-pin")) > + wdt->assert_wdt_timeout = true; This might be simpler written as wdt->assert_wdt_timeout = device_property_read_bool(...); > + > + /* initialize struct watchdog_device */ > + wdd = &wdt->wdd; > + wdd->parent = &pdev->dev; > + wdd->info = &sl28cpld_wdt_info; > + wdd->ops = &sl28cpld_wdt_ops; > + wdd->min_timeout = 1; > + wdd->max_timeout = 255; > + > + watchdog_set_drvdata(wdd, wdt); > + > + /* if the watchdog is locked, we set nowayout to true */ > + ret = sl28cpld_wdt_locked(wdt); > + if (ret < 0) > + return ret; > + if (ret) > + nowayout = true; > + watchdog_set_nowayout(wdd, nowayout); > + > + /* > + * Initial timeout value, can either be set by kernel parameter or by > + * the device tree. If both are not given the current value is used. > + */ > + watchdog_init_timeout(wdd, timeout, &pdev->dev); > + if (wdd->timeout) { > + sl28cpld_wdt_set_timeout(wdd, wdd->timeout); > + } else { > + ret = regmap_read(wdt->regmap, wdt->offset + WDT_TIMEOUT, > + &val); > + if (ret < 0) > + return ret; > + wdd->timeout = val; Oddly enough that can result in a timeout of 0 if that is what the chip reports. Are you sure that is acceptable ? > + } > + > + watchdog_stop_on_reboot(wdd); > + ret = devm_watchdog_register_device(&pdev->dev, wdd); This does not inform the watchdog core if the watchdog is already active, even though that is clearly supported. You might want to consider setting WDOG_HW_RUNNING in that case. > + if (ret < 0) { > + dev_err(&pdev->dev, "failed to register watchdog device\n"); > + return ret; > + } > + > + platform_set_drvdata(pdev, wdt); > + I don't see where this is used. > + dev_info(&pdev->dev, "CPLD watchdog: initial timeout %d sec%s\n", > + wdd->timeout, nowayout ? ", nowayout" : ""); > + > + return 0; > +} > + > +static const struct of_device_id sl28cpld_wdt_of_match[] = { > + { .compatible = "kontron,sl28cpld-wdt" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(of, sl28cpld_wdt_of_match); > + > +static const struct platform_device_id sl28cpld_wdt_id_table[] = { > + { "sl28cpld-wdt" }, > + {}, > +}; > +MODULE_DEVICE_TABLE(platform, sl28cpld_wdt_id_table); > + > +static struct platform_driver sl28cpld_wdt_driver = { > + .probe = sl28cpld_wdt_probe, > + .id_table = sl28cpld_wdt_id_table, > + .driver = { > + .name = KBUILD_MODNAME, > + .of_match_table = sl28cpld_wdt_of_match, > + }, > +}; > +module_platform_driver(sl28cpld_wdt_driver); > + > +MODULE_DESCRIPTION("sl28cpld Watchdog Driver"); > +MODULE_AUTHOR("Michael Walle "); > +MODULE_LICENSE("GPL");