+
+/**
+ * sysfs_get_class_device: Get specific class device using the device's id
+ * @class: class to find device on
+ * @name: class name of the device
+ */
+struct sysfs_class_device *sysfs_get_class_device(struct sysfs_class *class,
+ unsigned char *name)
+{
+ if (class == NULL || name == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ return (struct sysfs_class_device *)dlist_find_custom(class->devices,
+ name, class_name_equal);
+}
+
+/**
+ * sysfs_open_class_device_by_name: Locates a specific class_device and returns it.
+ * Class_device must be closed using sysfs_close_class_device
+ * @classname: Class to search
+ * @name: name of the class_device
+ */
+struct sysfs_class_device *sysfs_open_class_device_by_name
+ (const unsigned char *classname, unsigned char *name)
+{
+ struct sysfs_class *class = NULL;
+ struct sysfs_class_device *cdev = NULL, *rcdev = NULL;
+
+ if (classname == NULL || name == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ class = sysfs_open_class(classname);
+ if (class == NULL) {
+ dprintf("Error opening class %s\n", classname);
+ return NULL;
+ }
+
+ cdev = sysfs_get_class_device(class, name);
+ if (cdev == NULL) {
+ dprintf("Error getting class device %s from class %s\n",
+ name, classname);
+ sysfs_close_class(class);
+ return NULL;
+ }
+
+ rcdev = sysfs_open_class_device(cdev->directory->path);
+ if (rcdev == NULL) {
+ dprintf("Error getting class device %s from class %s\n",
+ name, classname);
+ sysfs_close_class(class);
+ return NULL;
+ }
+ sysfs_close_class(class);
+
+ return rcdev;
+}
+
+/**
+ * sysfs_get_classdev_attributes: returns a dlist of attributes for
+ * the requested class_device
+ * @cdev: sysfs_class_dev for which attributes are needed
+ * returns a dlist of attributes if exists, NULL otherwise
+ */
+struct dlist *sysfs_get_classdev_attributes(struct sysfs_class_device *cdev)
+{
+ if (cdev == NULL || cdev->directory == NULL)
+ return NULL;
+
+ return (cdev->directory->attributes);
+}
+
+/**
+ * sysfs_find_device_class: locates the device the device is on
+ * @bus_id: device to look for
+ * @classname: buffer to copy class name to
+ * @bsize: size of buffer
+ * returns 0 with success and -1 with error
+ */
+int sysfs_find_device_class(const unsigned char *bus_id,
+ unsigned char *classname, size_t bsize)
+{
+ unsigned char class[SYSFS_NAME_LEN], clspath[SYSFS_NAME_LEN];
+ unsigned char *cls = NULL, *clsdev = NULL;
+ struct dlist *clslist = NULL, *clsdev_list = NULL;
+
+ if (bus_id == NULL || classname == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ strcpy(class, SYSFS_CLASS_DIR);
+ clslist = sysfs_open_subsystem_list(class);
+ if (clslist != NULL) {
+ dlist_for_each_data(clslist, cls, char) {
+ memset(clspath, 0, SYSFS_NAME_LEN);
+ strcpy(clspath, SYSFS_CLASS_DIR);
+ strcat(clspath, "/");
+ strcat(clspath, cls);
+ clsdev_list = sysfs_open_subsystem_list(clspath);
+ if (clsdev_list != NULL) {
+ dlist_for_each_data(clsdev_list,
+ clsdev, char) {
+ if (strcmp(bus_id, clsdev) == 0) {
+ strncpy(classname,
+ cls, bsize);
+ sysfs_close_list(clsdev_list);
+ sysfs_close_list(clslist);
+ return 0;
+ }
+ }
+ sysfs_close_list(clsdev_list);
+ }
+ }
+ sysfs_close_list(clslist);
+ }
+ return -1;
+}
+
+/**
+ * sysfs_get_classdev_attr: searches class device's attributes by name
+ * @clsdev: class device to look through
+ * @name: attribute name to get
+ * returns sysfs_attribute reference with success or NULL with error
+ */
+struct sysfs_attribute *sysfs_get_classdev_attr
+ (struct sysfs_class_device *clsdev, const unsigned char *name)
+{
+ struct sysfs_attribute *cur = NULL;
+
+ if (clsdev == NULL || clsdev->directory == NULL ||
+ clsdev->directory->attributes == NULL || name == NULL) {
+ errno = EINVAL;
+ return NULL;
+ }
+
+ cur = sysfs_get_directory_attribute(clsdev->directory,
+ (unsigned char *)name);
+ if (cur != NULL)
+ return cur;
+
+ return NULL;
+}
+
+/**
+ * sysfs_write_classdev_attr: modify writable attribute value for the given
+ * class device
+ * @dev: class device name for which the attribute has to be changed
+ * @attrib: attribute to change
+ * @value: value to change to
+ * @len: size of buffer at "value"
+ * Returns 0 on success and -1 on error
+ */
+int sysfs_write_classdev_attr(unsigned char *dev, unsigned char *attrib,
+ unsigned char *value, size_t len)
+{
+ struct sysfs_class_device *clsdev = NULL;
+ struct sysfs_attribute *attribute = NULL;
+ unsigned char class_name[SYSFS_NAME_LEN];
+
+ if (dev == NULL || attrib == NULL || value == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(class_name, 0, SYSFS_NAME_LEN);
+ if ((sysfs_find_device_class(dev,
+ class_name, SYSFS_NAME_LEN)) < 0) {
+ dprintf("Class device %s not found\n", dev);
+ return -1;
+ }
+ clsdev = sysfs_open_class_device_by_name(class_name, dev);
+ if (clsdev == NULL) {
+ dprintf("Error opening %s in class %s\n", dev, class_name);
+ return -1;
+ }
+ attribute = sysfs_get_directory_attribute(clsdev->directory, attrib);
+ if (attribute == NULL) {
+ dprintf("Attribute %s not defined for device %s on class %s\n",
+ attrib, dev, class_name);
+ sysfs_close_class_device(clsdev);
+ return -1;
+ }
+ if ((sysfs_write_attribute(attribute, value, len)) < 0) {
+ dprintf("Error setting %s to %s\n", attrib, value);
+ sysfs_close_class_device(clsdev);
+ return -1;
+ }
+ sysfs_close_class_device(clsdev);
+ return 0;
+}
+
+/**
+ * sysfs_read_classdev_attr: read an attribute for a given class device
+ * @dev: class device name for which the attribute has to be read
+ * @attrib: attribute to read
+ * @value: buffer to return value to user
+ * @len: size of buffer at "value"
+ * Returns 0 on success and -1 on error
+ */
+int sysfs_read_classdev_attr(unsigned char *dev, unsigned char *attrib,
+ unsigned char *value, size_t len)
+{
+ struct sysfs_class_device *clsdev = NULL;
+ struct sysfs_attribute *attribute = NULL;
+ unsigned char class_name[SYSFS_NAME_LEN];
+
+ if (dev == NULL || attrib == NULL || value == NULL) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(class_name, 0, SYSFS_NAME_LEN);
+ if ((sysfs_find_device_class(dev,
+ class_name, SYSFS_NAME_LEN)) < 0) {
+ dprintf("Class device %s not found\n", dev);
+ return -1;
+ }
+ clsdev = sysfs_open_class_device_by_name(class_name, dev);
+ if (clsdev == NULL) {
+ dprintf("Error opening %s in class %s\n", dev, class_name);
+ return -1;
+ }
+ attribute = sysfs_get_directory_attribute(clsdev->directory, attrib);
+ if (attribute == NULL) {
+ dprintf("Attribute %s not defined for device %s on class %s\n",
+ attrib, dev, class_name);
+ sysfs_close_class_device(clsdev);
+ return -1;
+ }
+ if (attribute->len > len) {
+ dprintf("Value length %d is greater that suppled buffer %d\n",
+ attribute->len, len);
+ sysfs_close_class_device(clsdev);
+ return -1;
+ }
+ strncpy(value, attribute->value, attribute->len);
+ value[(attribute->len)+1] = 0;
+ sysfs_close_class_device(clsdev);
+ return 0;
+}