diff options
Diffstat (limited to 'drivers/watchdog/watchdog_core.c')
| -rw-r--r-- | drivers/watchdog/watchdog_core.c | 143 |
1 files changed, 129 insertions, 14 deletions
diff --git a/drivers/watchdog/watchdog_core.c b/drivers/watchdog/watchdog_core.c index cfa1a1518aa..cec9b559647 100644 --- a/drivers/watchdog/watchdog_core.c +++ b/drivers/watchdog/watchdog_core.c @@ -34,8 +34,69 @@ #include <linux/kernel.h> /* For printk/panic/... */ #include <linux/watchdog.h> /* For watchdog specific items */ #include <linux/init.h> /* For __init/__exit/... */ +#include <linux/idr.h> /* For ida_* macros */ +#include <linux/err.h> /* For IS_ERR macros */ +#include <linux/of.h> /* For of_get_timeout_sec */ -#include "watchdog_dev.h" /* For watchdog_dev_register/... */ +#include "watchdog_core.h" /* For watchdog_dev_register/... */ + +static DEFINE_IDA(watchdog_ida); +static struct class *watchdog_class; + +static void watchdog_check_min_max_timeout(struct watchdog_device *wdd) +{ + /* + * Check that we have valid min and max timeout values, if + * not reset them both to 0 (=not used or unknown) + */ + if (wdd->min_timeout > wdd->max_timeout) { + pr_info("Invalid min and max timeout values, resetting to 0!\n"); + wdd->min_timeout = 0; + wdd->max_timeout = 0; + } +} + +/** + * watchdog_init_timeout() - initialize the timeout field + * @timeout_parm: timeout module parameter + * @dev: Device that stores the timeout-sec property + * + * Initialize the timeout field of the watchdog_device struct with either the + * timeout module parameter (if it is valid value) or the timeout-sec property + * (only if it is a valid value and the timeout_parm is out of bounds). + * If none of them are valid then we keep the old value (which should normally + * be the default timeout value. + * + * A zero is returned on success and -EINVAL for failure. + */ +int watchdog_init_timeout(struct watchdog_device *wdd, + unsigned int timeout_parm, struct device *dev) +{ + unsigned int t = 0; + int ret = 0; + + watchdog_check_min_max_timeout(wdd); + + /* try to get the timeout module parameter first */ + if (!watchdog_timeout_invalid(wdd, timeout_parm) && timeout_parm) { + wdd->timeout = timeout_parm; + return ret; + } + if (timeout_parm) + ret = -EINVAL; + + /* try to get the timeout_sec property */ + if (dev == NULL || dev->of_node == NULL) + return ret; + of_property_read_u32(dev->of_node, "timeout-sec", &t); + if (!watchdog_timeout_invalid(wdd, t) && t) + wdd->timeout = t; + else + ret = -EINVAL; + + return ret; +} +EXPORT_SYMBOL_GPL(watchdog_init_timeout); /** * watchdog_register_device() - register a watchdog device @@ -49,7 +110,7 @@ */ int watchdog_register_device(struct watchdog_device *wdd) { - int ret; + int ret, id, devno; if (wdd == NULL || wdd->info == NULL || wdd->ops == NULL) return -EINVAL; @@ -58,15 +119,7 @@ int watchdog_register_device(struct watchdog_device *wdd) if (wdd->ops->start == NULL || wdd->ops->stop == NULL) return -EINVAL; - /* - * Check that we have valid min and max timeout values, if - * not reset them both to 0 (=not used or unknown) - */ - if (wdd->min_timeout > wdd->max_timeout) { - pr_info("Invalid min and max timeout values, resetting to 0!\n"); - wdd->min_timeout = 0; - wdd->max_timeout = 0; - } + watchdog_check_min_max_timeout(wdd); /* * Note: now that all watchdog_device data has been verified, we @@ -74,10 +127,38 @@ int watchdog_register_device(struct watchdog_device *wdd) * corrupted in a later stage then we expect a kernel panic! */ - /* We only support 1 watchdog device via the /dev/watchdog interface */ + mutex_init(&wdd->lock); + id = ida_simple_get(&watchdog_ida, 0, MAX_DOGS, GFP_KERNEL); + if (id < 0) + return id; + wdd->id = id; + ret = watchdog_dev_register(wdd); if (ret) { - pr_err("error registering /dev/watchdog (err=%d).\n", ret); + ida_simple_remove(&watchdog_ida, id); + if (!(id == 0 && ret == -EBUSY)) + return ret; + + /* Retry in case a legacy watchdog module exists */ + id = ida_simple_get(&watchdog_ida, 1, MAX_DOGS, GFP_KERNEL); + if (id < 0) + return id; + wdd->id = id; + + ret = watchdog_dev_register(wdd); + if (ret) { + ida_simple_remove(&watchdog_ida, id); + return ret; + } + } + + devno = wdd->cdev.dev; + wdd->dev = device_create(watchdog_class, wdd->parent, devno, + NULL, "watchdog%d", wdd->id); + if (IS_ERR(wdd->dev)) { + watchdog_dev_unregister(wdd); + ida_simple_remove(&watchdog_ida, id); + ret = PTR_ERR(wdd->dev); return ret; } @@ -95,16 +176,50 @@ EXPORT_SYMBOL_GPL(watchdog_register_device); void watchdog_unregister_device(struct watchdog_device *wdd) { int ret; + int devno; if (wdd == NULL) return; + devno = wdd->cdev.dev; ret = watchdog_dev_unregister(wdd); if (ret) - pr_err("error unregistering /dev/watchdog (err=%d).\n", ret); + pr_err("error unregistering /dev/watchdog (err=%d)\n", ret); + device_destroy(watchdog_class, devno); + ida_simple_remove(&watchdog_ida, wdd->id); + wdd->dev = NULL; } EXPORT_SYMBOL_GPL(watchdog_unregister_device); +static int __init watchdog_init(void) +{ + int err; + + watchdog_class = class_create(THIS_MODULE, "watchdog"); + if (IS_ERR(watchdog_class)) { + pr_err("couldn't create class\n"); + return PTR_ERR(watchdog_class); + } + + err = watchdog_dev_init(); + if (err < 0) { + class_destroy(watchdog_class); + return err; + } + + return 0; +} + +static void __exit watchdog_exit(void) +{ + watchdog_dev_exit(); + class_destroy(watchdog_class); + ida_destroy(&watchdog_ida); +} + +subsys_initcall(watchdog_init); +module_exit(watchdog_exit); + MODULE_AUTHOR("Alan Cox <alan@lxorguk.ukuu.org.uk>"); MODULE_AUTHOR("Wim Van Sebroeck <wim@iguana.be>"); MODULE_DESCRIPTION("WatchDog Timer Driver Core"); |