diff options
author | Søren Andersen <san@rosetechnology.dk> | 2014-12-11 02:53:54 +0300 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2014-12-11 04:41:15 +0300 |
commit | 920f91e50c5bfcbc5fe68f46dc72a34a96e0ff16 (patch) | |
tree | 526c5420d8d24cae8e8dbc89da52bd76ceb096dc | |
parent | e9bc7363d634e8d2ef1955106c53f8266d724353 (diff) | |
download | linux-920f91e50c5bfcbc5fe68f46dc72a34a96e0ff16.tar.xz |
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/Kconfig | 8 | ||||
-rw-r--r-- | drivers/rtc/rtc-ds1374.c | 285 |
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); |