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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 2014-12-10 15:53:54 -08:00 committed by Linus Torvalds
parent e9bc7363d6
commit 920f91e50c
2 changed files with 293 additions and 0 deletions
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8
drivers/rtc/Kconfig
View File

@ -192,6 +192,14 @@ config RTC_DRV_DS1374
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

285
drivers/rtc/rtc-ds1374.c
View File

@ -4,6 +4,7 @@
* Based on code by Randy Vinson <rvinson@mvista.com>,
* which was based on the m41t00.c by Mark Greer <mgreer@mvista.com>.
*
* Copyright (C) 2014 Rose Technology
* Copyright (C) 2006-2007 Freescale Semiconductor
*
* 2005 (c) MontaVista Software, Inc. This file is licensed under
@ -26,6 +27,13 @@
#include <linux/workqueue.h>
#include <linux/slab.h>
#include <linux/pm.h>
#ifdef CONFIG_RTC_DRV_DS1374_WDT
#include <linux/fs.h>
#include <linux/ioctl.h>
#include <linux/miscdevice.h>
#include <linux/reboot.h>
#include <linux/watchdog.h>
#endif
#define DS1374_REG_TOD0 0x00 /* Time of Day */
#define DS1374_REG_TOD1 0x01
@ -49,6 +57,14 @@ static const struct i2c_device_id ds1374_id[] = {
};
MODULE_DEVICE_TABLE(i2c, ds1374_id);
#ifdef CONFIG_OF
static const struct of_device_id ds1374_of_match[] = {
{ .compatible = "dallas,ds1374" },
{ }
};
MODULE_DEVICE_TABLE(of, ds1374_of_match);
#endif
struct ds1374 {
struct i2c_client *client;
struct rtc_device *rtc;
@ -162,6 +178,7 @@ 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
/* 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.
@ -263,6 +280,7 @@ static int ds1374_set_alarm(struct device *dev, struct rtc_wkalrm *alarm)
mutex_unlock(&ds1374->mutex);
return ret;
}
#endif
static irqreturn_t ds1374_irq(int irq, void *dev_id)
{
@ -307,6 +325,7 @@ static void ds1374_work(struct work_struct *work)
mutex_unlock(&ds1374->mutex);
}
#ifndef CONFIG_RTC_DRV_DS1374_WDT
static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
{
struct i2c_client *client = to_i2c_client(dev);
@ -331,15 +350,260 @@ static int ds1374_alarm_irq_enable(struct device *dev, unsigned int enabled)
mutex_unlock(&ds1374->mutex);
return ret;
}
#endif
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
.read_alarm = ds1374_read_alarm,
.set_alarm = ds1374_set_alarm,
.alarm_irq_enable = ds1374_alarm_irq_enable,
#endif
};
#ifdef CONFIG_RTC_DRV_DS1374_WDT
/*
*****************************************************************************
*
* Watchdog Driver
*
*****************************************************************************
*/
static struct i2c_client *save_client;
/* Default margin */
#define WD_TIMO 131762
#define DRV_NAME "DS1374 Watchdog"
static int wdt_margin = WD_TIMO;
static unsigned long wdt_is_open;
module_param(wdt_margin, int, 0);
MODULE_PARM_DESC(wdt_margin, "Watchdog timeout in seconds (default 32s)");
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)
{
int ret = -ENOIOCTLCMD;
int cr;
ret = cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
if (ret < 0)
goto out;
/* 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);
if (ret < 0)
goto out;
/* Set new watchdog time */
ret = ds1374_write_rtc(save_client, timeout, DS1374_REG_WDALM0, 3);
if (ret) {
pr_info("rtc-ds1374 - couldn't set new watchdog time\n");
goto out;
}
/* Enable watchdog timer */
cr |= DS1374_REG_CR_WACE | DS1374_REG_CR_WDALM;
cr &= ~DS1374_REG_CR_AIE;
ret = i2c_smbus_write_byte_data(save_client, DS1374_REG_CR, cr);
if (ret < 0)
goto out;
return 0;
out:
return ret;
}
/*
* Reload the watchdog timer. (ie, pat the watchdog)
*/
static void ds1374_wdt_ping(void)
{
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);
}
static void ds1374_wdt_disable(void)
{
int ret = -ENOIOCTLCMD;
int cr;
cr = i2c_smbus_read_byte_data(save_client, DS1374_REG_CR);
/* Disable watchdog timer */
cr &= ~DS1374_REG_CR_WACE;
ret = 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 nonseekable_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;
}
/*
* 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;
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:
return put_user(wdt_margin, (int __user *)arg);
case WDIOC_SETOPTIONS:
if (copy_from_user(&options, (int __user *)arg, sizeof(int)))
return -EFAULT;
if (options & WDIOS_DISABLECARD) {
pr_info("rtc-ds1374: disable watchdog\n");
ds1374_wdt_disable();
}
if (options & WDIOS_ENABLECARD) {
pr_info("rtc-ds1374: enable watchdog\n");
ds1374_wdt_settimeout(wdt_margin);
ds1374_wdt_ping();
}
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,
.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,
};
#endif /*CONFIG_RTC_DRV_DS1374_WDT*/
/*
*****************************************************************************
*
* Driver Interface
*
*****************************************************************************
*/
static int ds1374_probe(struct i2c_client *client,
const struct i2c_device_id *id)
{
@ -378,12 +642,33 @@ static int ds1374_probe(struct i2c_client *client,
return PTR_ERR(ds1374->rtc);
}
#ifdef CONFIG_RTC_DRV_DS1374_WDT
save_client = client;
ret = misc_register(&ds1374_miscdev);
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;
}
static int ds1374_remove(struct i2c_client *client)
{
struct ds1374 *ds1374 = i2c_get_clientdata(client);
#ifdef CONFIG_RTC_DRV_DS1374_WDT
int res;
res = misc_deregister(&ds1374_miscdev);
if (!res)
ds1374_miscdev.parent = NULL;
unregister_reboot_notifier(&ds1374_wdt_notifier);
#endif
if (client->irq > 0) {
mutex_lock(&ds1374->mutex);