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=-10.0 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 E14F8C433DF for ; Mon, 20 Jul 2020 10:26:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA72220702 for ; Mon, 20 Jul 2020 10:26:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728187AbgGTK0f (ORCPT ); Mon, 20 Jul 2020 06:26:35 -0400 Received: from relay4-d.mail.gandi.net ([217.70.183.196]:58909 "EHLO relay4-d.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728001AbgGTK0f (ORCPT ); Mon, 20 Jul 2020 06:26:35 -0400 X-Originating-IP: 90.65.108.121 Received: from localhost (lfbn-lyo-1-1676-121.w90-65.abo.wanadoo.fr [90.65.108.121]) (Authenticated sender: alexandre.belloni@bootlin.com) by relay4-d.mail.gandi.net (Postfix) with ESMTPSA id 5BE2AE000E; Mon, 20 Jul 2020 10:26:29 +0000 (UTC) Date: Mon, 20 Jul 2020 12:26:29 +0200 From: Alexandre Belloni To: Johnson CH Chen =?utf-8?B?KOmZs+aYreWLsyk=?= Cc: Wim Van Sebroeck , Alessandro Zummo , "linux@roeck-us.net" , "linux-kernel@vger.kernel.org" , "linux-rtc@vger.kernel.org" , Stephen Rothwell , Randy Dunlap Subject: Re: [PATCH v5] rtc: rtc-ds1374: wdt: Use watchdog core for watchdog part Message-ID: <20200720102629.GE3428@piout.net> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: Sender: linux-rtc-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-rtc@vger.kernel.org On 20/07/2020 09:46:45+0000, Johnson CH Chen (陳昭勳) wrote: > Let ds1374 watchdog use watchdog core functions. It also includes > improving watchdog timer setting and nowayout, and just uses ioctl() > of watchdog core. > > Signed-off-by: Johnson Chen > Reported-by: Randy Dunlap > --- > v4->v5: > - Fix reported build error by replacing RTC_DRV_DS1374_WDT with WATCHDOG_CORE > This is not the correct solution as this will remove the alarm functionality for anyone enabling WATCHDOG. I already submitted a proper fix. > v3->v4: > - Fix coding styles > - Remove dev_info() in ds1374_wdt_settimeout() > - Fix missing error check > > v2->v3: > - Fix a problem reported by WATCHDOG_CORE if WATCHDOG > - Remove save_client > - Let wdt_margin be 0 for watchdog_init_timeout() > - Use dev_info() rather than pr_info() > - Avoid more strings in this driver > > v1->v2: > - Use ds1374_wdt_settimeout() before registering the watchdog > - Remove watchdog_unregister_device() because devm_watchdog_register_device() is used > - Remove ds1374_wdt_ping() > - TIMER_MARGIN_MAX to 4095 for 24-bit value > - Keep wdt_margin > - Fix coding styles > > drivers/rtc/Kconfig | 13 +- > drivers/rtc/rtc-ds1374.c | 272 ++++++++++----------------------------- > 2 files changed, 72 insertions(+), 213 deletions(-) > > diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig > index b54d87d45c89..fcc47a613635 100644 > --- a/drivers/rtc/Kconfig > +++ b/drivers/rtc/Kconfig > @@ -271,22 +271,17 @@ config RTC_DRV_DS1307_CENTURY > > config RTC_DRV_DS1374 > tristate "Dallas/Maxim DS1374" > + select WATCHDOG_CORE if WATCHDOG > help > If you say yes here you get support for Dallas Semiconductor > DS1374 real-time clock chips. If an interrupt is associated > - with the device, the alarm functionality is supported. > + with the device, the alarm functionality is supported. If > + WATCHDOG_CORE is enabled, Dallas/Maxim DS1374 watchdog timer > + is supported rather than alarm timer. > > This driver can also be built as a module. If so, the module > will be called rtc-ds1374. > > -config RTC_DRV_DS1374_WDT > - bool "Dallas/Maxim DS1374 watchdog timer" > - depends on RTC_DRV_DS1374 > - help > - If you say Y here you will get support for the > - watchdog timer in the Dallas Semiconductor DS1374 > - real-time clock chips. > - > config RTC_DRV_DS1672 > tristate "Dallas/Maxim DS1672" > help > diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c > index 9c51a12cf70f..fc6470f5c847 100644 > --- a/drivers/rtc/rtc-ds1374.c > +++ b/drivers/rtc/rtc-ds1374.c > @@ -29,7 +29,7 @@ > #include > #include > #include > -#ifdef CONFIG_RTC_DRV_DS1374_WDT > +#ifdef CONFIG_WATCHDOG_CORE > #include > #include > #include > @@ -46,6 +46,7 @@ > #define DS1374_REG_WDALM2 0x06 > #define DS1374_REG_CR 0x07 /* Control */ > #define DS1374_REG_CR_AIE 0x01 /* Alarm Int. Enable */ > +#define DS1374_REG_CR_WDSTR 0x08 /* 1=INT, 0=RST */ > #define DS1374_REG_CR_WDALM 0x20 /* 1=Watchdog, 0=Alarm */ > #define DS1374_REG_CR_WACE 0x40 /* WD/Alarm counter enable */ > #define DS1374_REG_SR 0x08 /* Status */ > @@ -71,7 +72,9 @@ struct ds1374 { > struct i2c_client *client; > struct rtc_device *rtc; > struct work_struct work; > - > +#ifdef CONFIG_WATCHDOG_CORE > + struct watchdog_device wdt; > +#endif > /* The mutex protects alarm operations, and prevents a race > * between the enable_irq() in the workqueue and the free_irq() > * in the remove function. > @@ -177,7 +180,7 @@ static int ds1374_set_time(struct device *dev, struct rtc_time *time) > return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4); > } > > -#ifndef CONFIG_RTC_DRV_DS1374_WDT > +#ifndef CONFIG_WATCHDOG_CORE > /* The ds1374 has a decrementer for an alarm, rather than a comparator. > * If the time of day is changed, then the alarm will need to be > * reset. > @@ -324,7 +327,7 @@ static void ds1374_work(struct work_struct *work) > mutex_unlock(&ds1374->mutex); > } > > -#ifndef CONFIG_RTC_DRV_DS1374_WDT > +#ifndef CONFIG_WATCHDOG_CORE > static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled) > { > struct i2c_client *client = to_i2c_client(dev); > @@ -354,14 +357,14 @@ static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled) > static const struct rtc_class_ops ds1374_rtc_ops = { > .read_time = ds1374_read_time, > .set_time = ds1374_set_time, > -#ifndef CONFIG_RTC_DRV_DS1374_WDT > +#ifndef CONFIG_WATCHDOG_CORE > .read_alarm = ds1374_read_alarm, > .set_alarm = ds1374_set_alarm, > .alarm_irq_enable = ds1374_alarm_irq_enable, > #endif > }; > > -#ifdef CONFIG_RTC_DRV_DS1374_WDT > +#ifdef CONFIG_WATCHDOG_CORE > /* > ***************************************************************************** > * > @@ -369,239 +372,99 @@ static const struct rtc_class_ops ds1374_rtc_ops = { > * > ***************************************************************************** > */ > -static struct i2c_client *save_client; > /* Default margin */ > -#define WD_TIMO 131762 > +#define TIMER_MARGIN_DEFAULT 32 > +#define TIMER_MARGIN_MIN 1 > +#define TIMER_MARGIN_MAX 4095 /* 24-bit value */ > > #define DRV_NAME "DS1374 Watchdog" > > -static int wdt_margin = WD_TIMO; > -static unsigned long wdt_is_open; > +static int wdt_margin; > module_param(wdt_margin, int, 0); > MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)"); > > +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 const struct watchdog_info ds1374_wdt_info = { > .identity = "DS1374 WTD", > .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | > WDIOF_MAGICCLOSE, > }; > > -static int ds1374_wdt_settimeout(unsigned int timeout) > +static int ds1374_wdt_settimeout(struct watchdog_device *wdt, unsigned int timeout) > { > - int ret = -ENOIOCTLCMD; > - int cr; > + struct ds1374 *ds1374 = watchdog_get_drvdata(wdt); > + struct i2c_client *client = ds1374->client; > + int ret, cr; > > - ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR); > - if (ret < 0) > - goto out; > + wdt->timeout = timeout; > + > + cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR); > + if (cr < 0) > + return cr; > > /* Disable any existing watchdog/alarm before setting the new one */ > cr &= ~DS1374_REG_CR_WACE; > > - ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr); > + ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); > if (ret < 0) > - goto out; > + return ret; > > /* Set new watchdog time */ > - ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3); > - if (ret) { > - pr_info("couldn't set new watchdog time\n"); > - goto out; > - } > + timeout = timeout * 4096; > + ret = ds1374_write_rtc(client, timeout, DS1374_REG_WDALM0, 3); > + if (ret) > + return ret; > > /* Enable watchdog timer */ > cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM; > + cr &= ~DS1374_REG_CR_WDSTR;/* for RST PIN */ > cr &= ~DS1374_REG_CR_AIE; > > - ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr); > + ret = i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); > if (ret < 0) > - goto out; > + return ret; > > return 0; > -out: > - return ret; > } > > - > /* > * Reload the watchdog timer. (ie, pat the watchdog) > */ > -static void ds1374_wdt_ping(void) > +static int ds1374_wdt_start(struct watchdog_device *wdt) > { > + struct ds1374 *ds1374 = watchdog_get_drvdata(wdt); > u32 val; > - int ret = 0; > > - ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3); > - if (ret) > - pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret); > + return ds1374_read_rtc(ds1374->client, &val, DS1374_REG_WDALM0, 3); > } > > -static void ds1374_wdt_disable(void) > +static int ds1374_wdt_stop(struct watchdog_device *wdt) > { > + struct ds1374 *ds1374 = watchdog_get_drvdata(wdt); > + struct i2c_client *client = ds1374->client; > int cr; > > - cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR); > + cr = i2c_smbus_read_byte_data(client, DS1374_REG_CR); > + if (cr < 0) > + return cr; > + > /* Disable watchdog timer */ > cr &= ~DS1374_REG_CR_WACE; > > - i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr); > -} > - > -/* > - * Watchdog device is opened, and watchdog starts running. > - */ > -static int ds1374_wdt_open(struct inode *inode, struct file *file) > -{ > - struct ds1374 *ds1374 = i2c_get_clientdata(save_client); > - > - if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) { > - mutex_lock(&ds1374->mutex); > - if (test_and_set_bit(0, &wdt_is_open)) { > - mutex_unlock(&ds1374->mutex); > - return -EBUSY; > - } > - /* > - * Activate > - */ > - wdt_is_open = 1; > - mutex_unlock(&ds1374->mutex); > - return stream_open(inode, file); > - } > - return -ENODEV; > -} > - > -/* > - * Close the watchdog device. > - */ > -static int ds1374_wdt_release(struct inode *inode, struct file *file) > -{ > - if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) > - clear_bit(0, &wdt_is_open); > - > - return 0; > + return i2c_smbus_write_byte_data(client, DS1374_REG_CR, cr); > } > > -/* > - * Pat the watchdog whenever device is written to. > - */ > -static ssize_t ds1374_wdt_write(struct file *file, const char __user *data, > - size_t len, loff_t *ppos) > -{ > - if (len) { > - ds1374_wdt_ping(); > - return 1; > - } > - return 0; > -} > - > -static ssize_t ds1374_wdt_read(struct file *file, char __user *data, > - size_t len, loff_t *ppos) > -{ > - return 0; > -} > - > -/* > - * Handle commands from user-space. > - */ > -static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd, > - unsigned long arg) > -{ > - int new_margin, options; > - > - switch (cmd) { > - case WDIOC_GETSUPPORT: > - return copy_to_user((struct watchdog_info __user *)arg, > - &ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0; > - > - case WDIOC_GETSTATUS: > - case WDIOC_GETBOOTSTATUS: > - return put_user(0, (int __user *)arg); > - case WDIOC_KEEPALIVE: > - ds1374_wdt_ping(); > - return 0; > - case WDIOC_SETTIMEOUT: > - if (get_user(new_margin, (int __user *)arg)) > - return -EFAULT; > - > - /* the hardware's tick rate is 4096 Hz, so > - * the counter value needs to be scaled accordingly > - */ > - new_margin <<= 12; > - if (new_margin < 1 || new_margin > 16777216) > - return -EINVAL; > - > - wdt_margin = new_margin; > - ds1374_wdt_settimeout(new_margin); > - ds1374_wdt_ping(); > - /* fallthrough */ > - case WDIOC_GETTIMEOUT: > - /* when returning ... inverse is true */ > - return put_user((wdt_margin >> 12), (int __user *)arg); > - case WDIOC_SETOPTIONS: > - if (copy_from_user(&options, (int __user *)arg, sizeof(int))) > - return -EFAULT; > - > - if (options & WDIOS_DISABLECARD) { > - pr_info("disable watchdog\n"); > - ds1374_wdt_disable(); > - return 0; > - } > - > - if (options & WDIOS_ENABLECARD) { > - pr_info("enable watchdog\n"); > - ds1374_wdt_settimeout(wdt_margin); > - ds1374_wdt_ping(); > - return 0; > - } > - return -EINVAL; > - } > - return -ENOTTY; > -} > - > -static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd, > - unsigned long arg) > -{ > - int ret; > - struct ds1374 *ds1374 = i2c_get_clientdata(save_client); > - > - mutex_lock(&ds1374->mutex); > - ret = ds1374_wdt_ioctl(file, cmd, arg); > - mutex_unlock(&ds1374->mutex); > - > - return ret; > -} > - > -static int ds1374_wdt_notify_sys(struct notifier_block *this, > - unsigned long code, void *unused) > -{ > - if (code == SYS_DOWN || code == SYS_HALT) > - /* Disable Watchdog */ > - ds1374_wdt_disable(); > - return NOTIFY_DONE; > -} > - > -static const struct file_operations ds1374_wdt_fops = { > - .owner = THIS_MODULE, > - .read = ds1374_wdt_read, > - .unlocked_ioctl = ds1374_wdt_unlocked_ioctl, > - .compat_ioctl = compat_ptr_ioctl, > - .write = ds1374_wdt_write, > - .open = ds1374_wdt_open, > - .release = ds1374_wdt_release, > - .llseek = no_llseek, > -}; > - > -static struct miscdevice ds1374_miscdev = { > - .minor = WATCHDOG_MINOR, > - .name = "watchdog", > - .fops = &ds1374_wdt_fops, > -}; > - > -static struct notifier_block ds1374_wdt_notifier = { > - .notifier_call = ds1374_wdt_notify_sys, > +static const struct watchdog_ops ds1374_wdt_ops = { > + .owner = THIS_MODULE, > + .start = ds1374_wdt_start, > + .stop = ds1374_wdt_stop, > + .set_timeout = ds1374_wdt_settimeout, > }; > - > -#endif /*CONFIG_RTC_DRV_DS1374_WDT*/ > +#endif /*CONFIG_WATCHDOG_CORE*/ > /* > ***************************************************************************** > * > @@ -651,17 +514,23 @@ static int ds1374_probe(struct i2c_client *client, > if (ret) > return ret; > > -#ifdef CONFIG_RTC_DRV_DS1374_WDT > - save_client = client; > - ret = misc_register(&ds1374_miscdev); > +#ifdef CONFIG_WATCHDOG_CORE > + ds1374->wdt.info = &ds1374_wdt_info; > + ds1374->wdt.ops = &ds1374_wdt_ops; > + ds1374->wdt.timeout = TIMER_MARGIN_DEFAULT; > + ds1374->wdt.min_timeout = TIMER_MARGIN_MIN; > + ds1374->wdt.max_timeout = TIMER_MARGIN_MAX; > + > + watchdog_init_timeout(&ds1374->wdt, wdt_margin, &client->dev); > + watchdog_set_nowayout(&ds1374->wdt, nowayout); > + watchdog_stop_on_reboot(&ds1374->wdt); > + watchdog_stop_on_unregister(&ds1374->wdt); > + watchdog_set_drvdata(&ds1374->wdt, ds1374); > + ds1374_wdt_settimeout(&ds1374->wdt, ds1374->wdt.timeout); > + > + ret = devm_watchdog_register_device(&client->dev, &ds1374->wdt); > if (ret) > return ret; > - ret = register_reboot_notifier(&ds1374_wdt_notifier); > - if (ret) { > - misc_deregister(&ds1374_miscdev); > - return ret; > - } > - ds1374_wdt_settimeout(131072); > #endif > > return 0; > @@ -670,11 +539,6 @@ static int ds1374_probe(struct i2c_client *client, > static int ds1374_remove(struct i2c_client *client) > { > struct ds1374 *ds1374 = i2c_get_clientdata(client); > -#ifdef CONFIG_RTC_DRV_DS1374_WDT > - misc_deregister(&ds1374_miscdev); > - ds1374_miscdev.parent = NULL; > - unregister_reboot_notifier(&ds1374_wdt_notifier); > -#endif > > if (client->irq > 0) { > mutex_lock(&ds1374->mutex); > -- > 2.20.1 -- Alexandre Belloni, Bootlin Embedded Linux and Kernel engineering https://bootlin.com