drivers/rtc/rtc-ds1374.c: add watchdog support
Add support for the watchdog functionality of the DS1374 rtc. Based on the m41t80 watchdog functionality Note: watchdog uses the same registers as alarm. [akpm@linux-foundation.org: don't forget mutex_unlock() in ds1374_wdt_open() error path] [akpm@linux-foundation.org: coding-style fixes] Signed-off-by: Soeren Andersen <san@rosetechnology.dk> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Søren Andersen
Linus Torvalds
parent
e9bc7363d6
commit
920f91e50c
2 changed files with 293 additions and 0 deletions
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@ -192,6 +192,14 @@ config RTC_DRV_DS1374
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This driver can also be built as a module. If so, the module
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will be called rtc-ds1374.
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config RTC_DRV_DS1374_WDT
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bool "Dallas/Maxim DS1374 watchdog timer"
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depends on RTC_DRV_DS1374
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help
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If you say Y here you will get support for the
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watchdog timer in the Dallas Semiconductor DS1374
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real-time clock chips.
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config RTC_DRV_DS1672
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tristate "Dallas/Maxim DS1672"
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help
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@ -4,6 +4,7 @@
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* Based on code by Randy Vinson <rvinson@mvista.com>,
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* which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>.
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*
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* Copyright (C) 2014 Rose Technology
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* Copyright (C) 2006-2007 Freescale Semiconductor
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*
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* 2005 (c) MontaVista Software, Inc. This file is licensed under
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@ -26,6 +27,13 @@
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#include <linux/workqueue.h>
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#include <linux/slab.h>
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#include <linux/pm.h>
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#ifdef CONFIG_RTC_DRV_DS1374_WDT
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#include <linux/fs.h>
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#include <linux/ioctl.h>
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#include <linux/miscdevice.h>
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#include <linux/reboot.h>
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#include <linux/watchdog.h>
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#endif
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#define DS1374_REG_TOD0 0x00 /* Time of Day */
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#define DS1374_REG_TOD1 0x01
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@ -49,6 +57,14 @@ static const struct i2c_device_id ds1374_id[] = {
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};
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MODULE_DEVICE_TABLE(i2c, ds1374_id);
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#ifdef CONFIG_OF
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static const struct of_device_id ds1374_of_match[] = {
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{ .compatible = "dallas,ds1374" },
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{ }
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};
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MODULE_DEVICE_TABLE(of, ds1374_of_match);
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#endif
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struct ds1374 {
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struct i2c_client *client;
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struct rtc_device *rtc;
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@ -162,6 +178,7 @@ static int ds1374_set_time(struct device *dev, struct rtc_time *time)
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return ds1374_write_rtc(client, itime, DS1374_REG_TOD0, 4);
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}
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#ifndef CONFIG_RTC_DRV_DS1374_WDT
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/* The ds1374 has a decrementer for an alarm, rather than a comparator.
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* If the time of day is changed, then the alarm will need to be
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* reset.
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@ -263,6 +280,7 @@ static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
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mutex_unlock(&ds1374->mutex);
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return ret;
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}
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#endif
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static irqreturn_t ds1374_irq(int irq, void *dev_id)
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{
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@ -307,6 +325,7 @@ static void ds1374_work(struct work_struct *work)
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mutex_unlock(&ds1374->mutex);
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}
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#ifndef CONFIG_RTC_DRV_DS1374_WDT
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static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
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{
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struct i2c_client *client = to_i2c_client(dev);
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@ -331,15 +350,260 @@ static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
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mutex_unlock(&ds1374->mutex);
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return ret;
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}
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#endif
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static const struct rtc_class_ops ds1374_rtc_ops = {
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.read_time = ds1374_read_time,
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.set_time = ds1374_set_time,
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#ifndef CONFIG_RTC_DRV_DS1374_WDT
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.read_alarm = ds1374_read_alarm,
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.set_alarm = ds1374_set_alarm,
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.alarm_irq_enable = ds1374_alarm_irq_enable,
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#endif
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};
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#ifdef CONFIG_RTC_DRV_DS1374_WDT
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/*
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*****************************************************************************
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*
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* Watchdog Driver
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*
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*****************************************************************************
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*/
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static struct i2c_client *save_client;
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/* Default margin */
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#define WD_TIMO 131762
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#define DRV_NAME "DS1374 Watchdog"
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static int wdt_margin = WD_TIMO;
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static unsigned long wdt_is_open;
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module_param(wdt_margin, int, 0);
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MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");
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static const struct watchdog_info ds1374_wdt_info = {
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.identity = "DS1374 WTD",
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.options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING |
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WDIOF_MAGICCLOSE,
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};
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static int ds1374_wdt_settimeout(unsigned int timeout)
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{
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int ret = -ENOIOCTLCMD;
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int cr;
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ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
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if (ret < 0)
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goto out;
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/* Disable any existing watchdog/alarm before setting the new one */
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cr &= ~DS1374_REG_CR_WACE;
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ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
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if (ret < 0)
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goto out;
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/* Set new watchdog time */
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ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
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if (ret) {
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pr_info("rtc-ds1374 - couldn't set new watchdog time\n");
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goto out;
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}
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/* Enable watchdog timer */
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cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM;
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cr &= ~DS1374_REG_CR_AIE;
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ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
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if (ret < 0)
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goto out;
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return 0;
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out:
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return ret;
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}
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/*
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* Reload the watchdog timer. (ie, pat the watchdog)
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*/
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static void ds1374_wdt_ping(void)
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{
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u32 val;
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int ret = 0;
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ret = ds1374_read_rtc(save_client, &val, DS1374_REG_WDALM0, 3);
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if (ret)
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pr_info("WD TICK FAIL!!!!!!!!!! %i\n", ret);
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}
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static void ds1374_wdt_disable(void)
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{
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int ret = -ENOIOCTLCMD;
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int cr;
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cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
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/* Disable watchdog timer */
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cr &= ~DS1374_REG_CR_WACE;
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ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
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}
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/*
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* Watchdog device is opened, and watchdog starts running.
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*/
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static int ds1374_wdt_open(struct inode *inode, struct file *file)
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{
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struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
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if (MINOR(inode->i_rdev) == WATCHDOG_MINOR) {
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mutex_lock(&ds1374->mutex);
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if (test_and_set_bit(0, &wdt_is_open)) {
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mutex_unlock(&ds1374->mutex);
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return -EBUSY;
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}
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/*
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* Activate
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*/
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wdt_is_open = 1;
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mutex_unlock(&ds1374->mutex);
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return nonseekable_open(inode, file);
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}
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return -ENODEV;
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}
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/*
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* Close the watchdog device.
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*/
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static int ds1374_wdt_release(struct inode *inode, struct file *file)
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{
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if (MINOR(inode->i_rdev) == WATCHDOG_MINOR)
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clear_bit(0, &wdt_is_open);
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return 0;
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}
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/*
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* Pat the watchdog whenever device is written to.
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*/
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static ssize_t ds1374_wdt_write(struct file *file, const char __user *data,
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size_t len, loff_t *ppos)
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{
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if (len) {
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ds1374_wdt_ping();
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return 1;
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}
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return 0;
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}
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static ssize_t ds1374_wdt_read(struct file *file, char __user *data,
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size_t len, loff_t *ppos)
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{
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return 0;
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}
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/*
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* Handle commands from user-space.
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*/
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static long ds1374_wdt_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int new_margin, options;
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switch (cmd) {
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case WDIOC_GETSUPPORT:
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return copy_to_user((struct watchdog_info __user *)arg,
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&ds1374_wdt_info, sizeof(ds1374_wdt_info)) ? -EFAULT : 0;
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case WDIOC_GETSTATUS:
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case WDIOC_GETBOOTSTATUS:
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return put_user(0, (int __user *)arg);
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case WDIOC_KEEPALIVE:
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ds1374_wdt_ping();
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return 0;
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case WDIOC_SETTIMEOUT:
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if (get_user(new_margin, (int __user *)arg))
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return -EFAULT;
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if (new_margin < 1 || new_margin > 16777216)
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return -EINVAL;
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wdt_margin = new_margin;
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ds1374_wdt_settimeout(new_margin);
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ds1374_wdt_ping();
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/* fallthrough */
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case WDIOC_GETTIMEOUT:
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return put_user(wdt_margin, (int __user *)arg);
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case WDIOC_SETOPTIONS:
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if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
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return -EFAULT;
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if (options & WDIOS_DISABLECARD) {
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pr_info("rtc-ds1374: disable watchdog\n");
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ds1374_wdt_disable();
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}
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if (options & WDIOS_ENABLECARD) {
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pr_info("rtc-ds1374: enable watchdog\n");
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ds1374_wdt_settimeout(wdt_margin);
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ds1374_wdt_ping();
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}
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return -EINVAL;
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}
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return -ENOTTY;
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}
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static long ds1374_wdt_unlocked_ioctl(struct file *file, unsigned int cmd,
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unsigned long arg)
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{
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int ret;
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struct ds1374 *ds1374 = i2c_get_clientdata(save_client);
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mutex_lock(&ds1374->mutex);
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ret = ds1374_wdt_ioctl(file, cmd, arg);
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mutex_unlock(&ds1374->mutex);
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return ret;
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}
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static int ds1374_wdt_notify_sys(struct notifier_block *this,
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unsigned long code, void *unused)
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{
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if (code == SYS_DOWN || code == SYS_HALT)
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/* Disable Watchdog */
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ds1374_wdt_disable();
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return NOTIFY_DONE;
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}
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static const struct file_operations ds1374_wdt_fops = {
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.owner = THIS_MODULE,
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.read = ds1374_wdt_read,
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.unlocked_ioctl = ds1374_wdt_unlocked_ioctl,
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.write = ds1374_wdt_write,
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.open = ds1374_wdt_open,
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.release = ds1374_wdt_release,
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.llseek = no_llseek,
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};
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static struct miscdevice ds1374_miscdev = {
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.minor = WATCHDOG_MINOR,
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.name = "watchdog",
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.fops = &ds1374_wdt_fops,
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};
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static struct notifier_block ds1374_wdt_notifier = {
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.notifier_call = ds1374_wdt_notify_sys,
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};
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#endif /*CONFIG_RTC_DRV_DS1374_WDT*/
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/*
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*****************************************************************************
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*
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* Driver Interface
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*
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*****************************************************************************
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*/
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static int ds1374_probe(struct i2c_client *client,
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const struct i2c_device_id *id)
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{
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@ -378,12 +642,33 @@ static int ds1374_probe(struct i2c_client *client,
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return PTR_ERR(ds1374->rtc);
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}
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#ifdef CONFIG_RTC_DRV_DS1374_WDT
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save_client = client;
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ret = misc_register(&ds1374_miscdev);
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if (ret)
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return ret;
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ret = register_reboot_notifier(&ds1374_wdt_notifier);
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if (ret) {
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misc_deregister(&ds1374_miscdev);
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return ret;
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}
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ds1374_wdt_settimeout(131072);
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#endif
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return 0;
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}
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static int ds1374_remove(struct i2c_client *client)
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{
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struct ds1374 *ds1374 = i2c_get_clientdata(client);
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#ifdef CONFIG_RTC_DRV_DS1374_WDT
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int res;
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res = misc_deregister(&ds1374_miscdev);
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if (!res)
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ds1374_miscdev.parent = NULL;
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unregister_reboot_notifier(&ds1374_wdt_notifier);
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#endif
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if (client->irq > 0) {
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mutex_lock(&ds1374->mutex);
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