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authorSøren Andersen <san@rosetechnology.dk>2014-12-10 15:53:54 -0800
committerLinus Torvalds <torvalds@linux-foundation.org>2014-12-10 17:41:15 -0800
commit920f91e50c5bfcbc5fe68f46dc72a34a96e0ff16 (patch)
tree526c5420d8d24cae8e8dbc89da52bd76ceb096dc
parente9bc7363d634e8d2ef1955106c53f8266d724353 (diff)
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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>
-rw-r--r--drivers/rtc/Kconfig8
-rw-r--r--drivers/rtc/rtc-ds1374.c285
2 files changed, 293 insertions, 0 deletions
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index b682651b5307..4511ddc1ac31 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -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
diff --git a/drivers/rtc/rtc-ds1374.c b/drivers/rtc/rtc-ds1374.c
index 9e6e14fb53d7..8605fde394b2 100644
--- a/drivers/rtc/rtc-ds1374.c
+++ b/drivers/rtc/rtc-ds1374.c
@@ -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 @@ out:
mutex_unlock(&ds1374->mutex);
return ret;
}
+#endif
static irqreturn_t ds1374_irq(int irq, void *dev_id)
{
@@ -307,6 +325,7 @@ unlock:
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 @@ out:
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);