/*
 * libsysfs.h
 *
 * Header Definitions for libsysfs
 *
 * Copyright (C) IBM Corp. 2004-2005
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser General Public
 *  License as published by the Free Software Foundation; either
 *  version 2.1 of the License, or (at your option) any later version.
 *
 *  This library is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
 *
 */
#ifndef _LIBSYSFS_H_
#define _LIBSYSFS_H_

#include <sys/types.h>
#include <string.h>
#include "dlist.h"

#define SYSFS_FSTYPE_NAME	"sysfs"
#define SYSFS_PROC_MNTS		"/proc/mounts"
#define SYSFS_BUS_NAME		"bus"
#define SYSFS_CLASS_NAME	"class"
#define SYSFS_BLOCK_NAME	"block"
#define SYSFS_DEVICES_NAME	"devices"
#define SYSFS_DRIVERS_NAME	"drivers"
#define SYSFS_MODULE_NAME	"module"
#define SYSFS_NAME_ATTRIBUTE	"name"
#define SYSFS_UNKNOWN		"unknown"
#define SYSFS_PATH_ENV		"SYSFS_PATH"

#define SYSFS_PATH_MAX		256
#define	SYSFS_NAME_LEN		64
#define SYSFS_BUS_ID_SIZE	32

/* mount path for sysfs, can be overridden by exporting SYSFS_PATH */
#define SYSFS_MNT_PATH		"/sys"

enum sysfs_attribute_method {
	SYSFS_METHOD_SHOW =	0x01,	/* attr can be read by user */
	SYSFS_METHOD_STORE =	0x02,	/* attr can be changed by user */
};

/*
 * NOTE: 
 * 1. We have the statically allocated "name" as the first element of all 
 * the structures. This feature is used in the "sorter" function for dlists
 * 2. As is the case with attrlist
 * 3. As is the case with path
 */
struct sysfs_attribute {
	char name[SYSFS_NAME_LEN];
	char path[SYSFS_PATH_MAX];
	char *value;
	unsigned short len;			/* value length */
	enum sysfs_attribute_method method;	/* show and store */
};

struct sysfs_driver {
	char name[SYSFS_NAME_LEN];
	char path[SYSFS_PATH_MAX];
	struct dlist *attrlist;
	char bus[SYSFS_NAME_LEN];

	/* Private: for internal use only */
	struct dlist *devices;
};

struct sysfs_device {
	char name[SYSFS_NAME_LEN];
	char path[SYSFS_PATH_MAX];
	struct dlist *attrlist;
	char bus_id[SYSFS_NAME_LEN];
	char bus[SYSFS_NAME_LEN];
	char driver_name[SYSFS_NAME_LEN];

	/* Private: for internal use only */
	struct sysfs_device *parent;		
	/* NOTE - we still don't populate this */
	struct dlist *children;	
};

/* NOTE: not used as of now */
struct sysfs_bus {
	char name[SYSFS_NAME_LEN];
	char path[SYSFS_PATH_MAX];
	struct dlist *attrlist;

	/* Private: for internal use only */
	struct dlist *drivers;
	struct dlist *devices;
};

struct sysfs_class_device {
	char name[SYSFS_NAME_LEN];
	char path[SYSFS_PATH_MAX];
	struct dlist *attrlist;
	char classname[SYSFS_NAME_LEN];

	/* Private: for internal use only */
	struct sysfs_class_device *parent;	
	struct sysfs_device *sysdevice;		/* NULL if virtual */
};

/* NOTE: not used as of now */
struct sysfs_class {
	char name[SYSFS_NAME_LEN];
	char path[SYSFS_PATH_MAX];
	struct dlist *attrlist;

	/* Private: for internal use only */
	struct dlist *devices;
};

#ifdef __cplusplus
extern "C" {
#endif

/*
 * Function Prototypes
 */
extern int sysfs_get_mnt_path(char *mnt_path, size_t len);
extern int sysfs_remove_trailing_slash(char *path);
extern int sysfs_get_name_from_path(const char *path, char *name, size_t len);
extern int sysfs_path_is_dir(const char *path);
extern int sysfs_path_is_link(const char *path);
extern int sysfs_path_is_file(const char *path);
extern int sysfs_get_link(const char *path, char *target, size_t len);
extern struct dlist *sysfs_open_directory_list(const char *path);
extern void sysfs_close_list(struct dlist *list);

/* sysfs directory and file access */
extern void sysfs_close_attribute(struct sysfs_attribute *sysattr);
extern struct sysfs_attribute *sysfs_open_attribute(const char *path);
extern int sysfs_read_attribute(struct sysfs_attribute *sysattr);
extern int sysfs_write_attribute(struct sysfs_attribute *sysattr,
		const char *new_value, size_t len);

/* sysfs driver access */
extern void sysfs_close_driver(struct sysfs_driver *driver);
extern struct sysfs_driver *sysfs_open_driver
	(const char *bus_name, const char *drv_name);
extern struct sysfs_driver *sysfs_open_driver_path(const char *path);
extern struct sysfs_attribute *sysfs_get_driver_attr
	(struct sysfs_driver *drv, const char *name);
extern struct dlist *sysfs_get_driver_attributes(struct sysfs_driver *driver);
extern struct dlist *sysfs_get_driver_devices(struct sysfs_driver *driver);

/* generic sysfs device access */
extern void sysfs_close_device_tree(struct sysfs_device *device);
extern struct sysfs_device *sysfs_open_device_tree(const char *path);
extern void sysfs_close_device(struct sysfs_device *dev);
extern struct sysfs_device *sysfs_open_device
	(const char *bus, const char *bus_id);
extern struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev);
extern struct sysfs_device *sysfs_open_device_path(const char *path);
extern int sysfs_get_device_bus(struct sysfs_device *dev);
extern struct sysfs_attribute *sysfs_get_device_attr
	(struct sysfs_device *dev, const char *name);
extern struct dlist *sysfs_get_device_attributes
	(struct sysfs_device *dev);

/* generic sysfs class access */
extern void sysfs_close_class_device(struct sysfs_class_device *dev);
extern struct sysfs_class_device *sysfs_open_class_device_path
	(const char *path);
extern struct sysfs_class_device *sysfs_open_class_device
	(const char *classname, const char *name);
extern struct sysfs_class_device *sysfs_get_classdev_parent
	(struct sysfs_class_device *clsdev);
extern struct sysfs_attribute *sysfs_get_classdev_attr
	(struct sysfs_class_device *clsdev, const char *name);
extern struct dlist *sysfs_get_classdev_attributes
	(struct sysfs_class_device *clsdev);
extern struct sysfs_device *sysfs_get_classdev_device
	(struct sysfs_class_device *clsdev);

/**
 * sort_list: sorter function to keep list elements sorted in alphabetical 
 * 	order. Just does a strncmp as you can see :)
 * 	
 * Returns 1 if less than 0 otherwise
 *
 * NOTE: We take care to have a statically allocated "name" as the first 
 * 	lement of all libsysfs structures. Hence, this function will work 
 * 	AS IS for _ALL_ the lists that have to be sorted.
 */
static inline int sort_list(void *new_elem, void *old_elem)
{
        return ((strncmp(((struct sysfs_attribute *)new_elem)->name,
		((struct sysfs_attribute *)old_elem)->name,
		strlen(((struct sysfs_attribute *)new_elem)->name))) < 0 ? 1 : 0);
}


#ifdef __cplusplus
}
#endif

#endif /* _LIBSYSFS_H_ */