diff options
Diffstat (limited to 'drivers/hwmon/hwmon.c')
| -rw-r--r-- | drivers/hwmon/hwmon.c | 113 |
1 files changed, 113 insertions, 0 deletions
diff --git a/drivers/hwmon/hwmon.c b/drivers/hwmon/hwmon.c new file mode 100644 index 0000000..076a59c --- /dev/null +++ b/drivers/hwmon/hwmon.c @@ -0,0 +1,113 @@ +/* + hwmon.c - part of lm_sensors, Linux kernel modules for hardware monitoring + + This file defines the sysfs class "hwmon", for use by sensors drivers. + + Copyright (C) 2005 Mark M. Hoffman <mhoffman@lightlink.com> + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; version 2 of the License. +*/ + +#include <linux/module.h> +#include <linux/device.h> +#include <linux/err.h> +#include <linux/kdev_t.h> +#include <linux/idr.h> +#include <linux/hwmon.h> +#include <linux/gfp.h> +#include <linux/spinlock.h> + +#define HWMON_ID_PREFIX "hwmon" +#define HWMON_ID_FORMAT HWMON_ID_PREFIX "%d" + +static struct class *hwmon_class; + +static DEFINE_IDR(hwmon_idr); +static DEFINE_SPINLOCK(idr_lock); + +/** + * hwmon_device_register - register w/ hwmon + * @dev: the device to register + * + * hwmon_device_unregister() must be called when the device is no + * longer needed. + * + * Returns the pointer to the new device. + */ +struct device *hwmon_device_register(struct device *dev) +{ + struct device *hwdev; + int id, err; + +again: + if (unlikely(idr_pre_get(&hwmon_idr, GFP_KERNEL) == 0)) + return ERR_PTR(-ENOMEM); + + spin_lock(&idr_lock); + err = idr_get_new(&hwmon_idr, NULL, &id); + spin_unlock(&idr_lock); + + if (unlikely(err == -EAGAIN)) + goto again; + else if (unlikely(err)) + return ERR_PTR(err); + + id = id & MAX_ID_MASK; + hwdev = device_create(hwmon_class, dev, MKDEV(0, 0), NULL, + HWMON_ID_FORMAT, id); + + if (IS_ERR(hwdev)) { + spin_lock(&idr_lock); + idr_remove(&hwmon_idr, id); + spin_unlock(&idr_lock); + } + + return hwdev; +} + +/** + * hwmon_device_unregister - removes the previously registered class device + * + * @dev: the class device to destroy + */ +void hwmon_device_unregister(struct device *dev) +{ + int id; + + if (likely(sscanf(dev->bus_id, HWMON_ID_FORMAT, &id) == 1)) { + device_unregister(dev); + spin_lock(&idr_lock); + idr_remove(&hwmon_idr, id); + spin_unlock(&idr_lock); + } else + dev_dbg(dev->parent, + "hwmon_device_unregister() failed: bad class ID!\n"); +} + +static int __init hwmon_init(void) +{ + hwmon_class = class_create(THIS_MODULE, "hwmon"); + if (IS_ERR(hwmon_class)) { + printk(KERN_ERR "hwmon.c: couldn't create sysfs class\n"); + return PTR_ERR(hwmon_class); + } + return 0; +} + +static void __exit hwmon_exit(void) +{ + class_destroy(hwmon_class); +} + +subsys_initcall(hwmon_init); +module_exit(hwmon_exit); + +EXPORT_SYMBOL_GPL(hwmon_device_register); +EXPORT_SYMBOL_GPL(hwmon_device_unregister); + +MODULE_AUTHOR("Mark M. Hoffman <mhoffman@lightlink.com>"); +MODULE_DESCRIPTION("hardware monitoring sysfs/class support"); +MODULE_LICENSE("GPL"); + |
