root/include/linux/sysdev.h

INCLUDED FROM

/**
 * System devices follow a slightly different driver model. 
 * They don't need to do dynammic driver binding, can't be probed, 
 * and don't reside on any type of peripheral bus. 
 * So, we represent and treat them a little differently.
 * 
 * We still have a notion of a driver for a system device, because we still
 * want to perform basic operations on these devices. 
 *
 * We also support auxillary drivers binding to devices of a certain class.
 * 
 * This allows configurable drivers to register themselves for devices of
 * a certain type. And, it allows class definitions to reside in generic
 * code while arch-specific code can register specific drivers.
 *
 * Auxillary drivers registered with a NULL cls are registered as drivers
 * for all system devices, and get notification calls for each device. 
 */


#ifndef _SYSDEV_H_
#define _SYSDEV_H_

#include <linux/kobject.h>
#include <linux/module.h>
#include <linux/pm.h>


struct sys_device;

struct sysdev_class {
        const char *name;
        struct list_head        drivers;

        /* Default operations for these types of devices */
        int     (*shutdown)(struct sys_device *);
        int     (*suspend)(struct sys_device *, pm_message_t state);
        int     (*resume)(struct sys_device *);
        struct kset             kset;
};

struct sysdev_class_attribute {
        struct attribute attr;
        ssize_t (*show)(struct sysdev_class *, char *);
        ssize_t (*store)(struct sysdev_class *, const char *, size_t);
};

#define _SYSDEV_CLASS_ATTR(_name,_mode,_show,_store)            \
{                                                               \
        .attr = {.name = __stringify(_name), .mode = _mode },   \
        .show   = _show,                                        \
        .store  = _store,                                       \
}

#define SYSDEV_CLASS_ATTR(_name,_mode,_show,_store)             \
        struct sysdev_class_attribute attr_##_name =            \
                _SYSDEV_CLASS_ATTR(_name,_mode,_show,_store)


extern int sysdev_class_register(struct sysdev_class *);
extern void sysdev_class_unregister(struct sysdev_class *);

extern int sysdev_class_create_file(struct sysdev_class *,
        struct sysdev_class_attribute *);
extern void sysdev_class_remove_file(struct sysdev_class *,
        struct sysdev_class_attribute *);
/**
 * Auxillary system device drivers.
 */

struct sysdev_driver {
        struct list_head        entry;
        int     (*add)(struct sys_device *);
        int     (*remove)(struct sys_device *);
        int     (*shutdown)(struct sys_device *);
        int     (*suspend)(struct sys_device *, pm_message_t state);
        int     (*resume)(struct sys_device *);
};


extern int sysdev_driver_register(struct sysdev_class *, struct sysdev_driver *);
extern void sysdev_driver_unregister(struct sysdev_class *, struct sysdev_driver *);


/**
 * sys_devices can be simplified a lot from regular devices, because they're
 * simply not as versatile. 
 */

struct sys_device {
        u32             id;
        struct sysdev_class     * cls;
        struct kobject          kobj;
};

extern int sysdev_register(struct sys_device *);
extern void sysdev_unregister(struct sys_device *);


struct sysdev_attribute { 
        struct attribute        attr;
        ssize_t (*show)(struct sys_device *, struct sysdev_attribute *, char *);
        ssize_t (*store)(struct sys_device *, struct sysdev_attribute *,
                         const char *, size_t);
};


#define _SYSDEV_ATTR(_name, _mode, _show, _store)               \
{                                                               \
        .attr = { .name = __stringify(_name), .mode = _mode },  \
        .show   = _show,                                        \
        .store  = _store,                                       \
}

#define SYSDEV_ATTR(_name, _mode, _show, _store)                \
        struct sysdev_attribute attr_##_name =                  \
                _SYSDEV_ATTR(_name, _mode, _show, _store);

extern int sysdev_create_file(struct sys_device *, struct sysdev_attribute *);
extern void sysdev_remove_file(struct sys_device *, struct sysdev_attribute *);

struct sysdev_ext_attribute {
        struct sysdev_attribute attr;
        void *var;
};

/*
 * Support for simple variable sysdev attributes.
 * The pointer to the variable is stored in a sysdev_ext_attribute
 */

/* Add more types as needed */

extern ssize_t sysdev_show_ulong(struct sys_device *, struct sysdev_attribute *,
                                char *);
extern ssize_t sysdev_store_ulong(struct sys_device *,
                        struct sysdev_attribute *, const char *, size_t);
extern ssize_t sysdev_show_int(struct sys_device *, struct sysdev_attribute *,
                                char *);
extern ssize_t sysdev_store_int(struct sys_device *,
                        struct sysdev_attribute *, const char *, size_t);

#define _SYSDEV_ULONG_ATTR(_name, _mode, _var)                          \
        { _SYSDEV_ATTR(_name, _mode, sysdev_show_ulong, sysdev_store_ulong), \
          &(_var) }
#define SYSDEV_ULONG_ATTR(_name, _mode, _var)                   \
        struct sysdev_ext_attribute attr_##_name =              \
                _SYSDEV_ULONG_ATTR(_name, _mode, _var);
#define _SYSDEV_INT_ATTR(_name, _mode, _var)                            \
        { _SYSDEV_ATTR(_name, _mode, sysdev_show_int, sysdev_store_int), \
          &(_var) }
#define SYSDEV_INT_ATTR(_name, _mode, _var)                     \
        struct sysdev_ext_attribute attr_##_name =              \
                _SYSDEV_INT_ATTR(_name, _mode, _var);

#endif /* _SYSDEV_H_ */