*
* Generic device utility functions for libsysfs
*
- * Copyright (C) IBM Corp. 2003
+ * Copyright (C) IBM Corp. 2003-2005
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
#include "sysfs.h"
/**
- * sysfs_close_device_tree: closes every device in the supplied tree,
- * closing children only.
- * @devroot: device root of tree.
+ * get_dev_driver: fills in the dev->driver_name field
+ * Returns 0 on SUCCESS and -1 on error
*/
-static void sysfs_close_device_tree(struct sysfs_device *devroot)
+static int get_dev_driver(struct sysfs_device *dev)
{
- if (devroot != NULL) {
- if (devroot->children != NULL) {
- struct sysfs_device *child = NULL;
+ struct dlist *drvlist;
+ char path[SYSFS_PATH_MAX];
+ char devpath[SYSFS_PATH_MAX];
+ char *drv = NULL, *c;
- dlist_for_each_data(devroot->children, child,
- struct sysfs_device) {
- sysfs_close_device_tree(child);
+ if (!dev) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(path, 0, SYSFS_PATH_MAX);
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ safestrcpymax(path, dev->path, SYSFS_PATH_MAX);
+ safestrcatmax(path, "/driver", SYSFS_PATH_MAX);
+ if (!sysfs_path_is_link(path)) {
+ if (!sysfs_get_link(path, devpath, SYSFS_PATH_MAX)) {
+ if (sysfs_get_name_from_path(devpath,
+ dev->driver_name, SYSFS_NAME_LEN))
+ return -1;
+ }
+ return 0;
+ }
+
+ /*
+ * Devices on on earlier kernels do not have the "driver" link.
+ * Look it up in the bus directory.
+ */
+ if (dev->bus[0] == '\0')
+ return -1;
+ memset(path, 0, SYSFS_PATH_MAX);
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ safestrcpy(path, dev->path);
+ c = strstr(path, SYSFS_DEVICES_NAME);
+ if (c == NULL) {
+ dprintf("Invalid path to device - %s\n", dev->path);
+ return -1;
+ } else
+ *c = '\0';
+ safestrcat(path, SYSFS_BUS_NAME);
+ safestrcat(path, "/");
+ safestrcat(path, dev->bus);
+ safestrcat(path, "/");
+ safestrcat(path, SYSFS_DRIVERS_NAME);
+
+ drvlist = sysfs_open_directory_list(path);
+ if (drvlist) {
+ dlist_for_each_data(drvlist, drv, char) {
+ safestrcpy(devpath, path);
+ safestrcat(devpath, "/");
+ safestrcat(devpath, drv);
+ safestrcat(devpath, "/");
+ safestrcat(devpath, dev->bus_id);
+ if (sysfs_path_is_link(devpath) == 0) {
+ safestrcpy(dev->driver_name, drv);
+ sysfs_close_list(drvlist);
+ return 0;
}
}
- sysfs_close_device(devroot);
+ sysfs_close_list(drvlist);
}
+ return -1;
}
/**
- * sysfs_del_device: routine for dlist integration
+ * sysfs_get_device_bus: retrieves the bus name the device is on, checks path
+ * to bus' link to make sure it has correct device.
+ * @dev: device to get busname.
+ * returns 0 with success and -1 with error.
*/
-static void sysfs_del_device(void *dev)
+int sysfs_get_device_bus(struct sysfs_device *dev)
{
- sysfs_close_device((struct sysfs_device *)dev);
+ char devpath[SYSFS_PATH_MAX];
+ char subsys[SYSFS_NAME_LEN];
+ char path[SYSFS_PATH_MAX];
+ char target[SYSFS_PATH_MAX];
+ char *bus = NULL, *c;
+ struct dlist *buslist;
+
+ if (!dev) {
+ errno = EINVAL;
+ return -1;
+ }
+
+ memset(path, 0, SYSFS_PATH_MAX);
+ memset(devpath, 0, SYSFS_PATH_MAX);
+ safestrcpymax(path, dev->path, SYSFS_PATH_MAX);
+ safestrcatmax(path, "/bus", SYSFS_PATH_MAX);
+ if (!sysfs_path_is_link(path)) {
+ if (!sysfs_get_link(path, devpath, SYSFS_PATH_MAX)) {
+ if (sysfs_get_name_from_path(devpath,
+ dev->bus, SYSFS_NAME_LEN))
+ return -1;
+ }
+ return 0;
+ }
+
+ /*
+ * Devices on on earlier kernels do not have the "bus" link.
+ * Look it up in the bus directory.
+ */
+ memset(subsys, 0, SYSFS_NAME_LEN);
+ safestrcpy(subsys, dev->path);
+ c = strstr(subsys, SYSFS_DEVICES_NAME);
+ if (c == NULL) {
+ dprintf("Invalid path to device - %s\n", dev->path);
+ return -1;
+ } else
+ *c = '\0';
+ safestrcat(subsys, SYSFS_BUS_NAME);
+ buslist = sysfs_open_directory_list(subsys);
+ if (buslist) {
+ dlist_for_each_data(buslist, bus, char) {
+ memset(path, 0, SYSFS_PATH_MAX);
+ safestrcpy(path, subsys);
+ safestrcat(path, "/");
+ safestrcat(path, bus);
+ safestrcat(path, "/");
+ safestrcat(path, SYSFS_DEVICES_NAME);
+ safestrcat(path, "/");
+ safestrcat(path, dev->bus_id);
+ if ((sysfs_path_is_link(path)) == 0) {
+ memset(target, 0, SYSFS_PATH_MAX);
+ if (sysfs_get_link(path, target,
+ SYSFS_PATH_MAX)) {
+ dprintf("Error getting link target\n");
+ sysfs_close_list(buslist);
+ return -1;
+ }
+ if (!(strncmp(target, dev->path,
+ SYSFS_PATH_MAX))) {
+ safestrcpy(dev->bus, bus);
+ sysfs_close_list(buslist);
+ return 0;
+ }
+ }
+ }
+ sysfs_close_list(buslist);
+ }
+ return -1;
}
/**
- * sysfs_close_dev_tree: routine for dlist integration
+ * sysfs_close_device_tree: closes every device in the supplied tree,
+ * closing children only.
+ * @devroot: device root of tree.
*/
-static void sysfs_close_dev_tree(void *dev)
+void sysfs_close_device_tree(struct sysfs_device *devroot)
{
- sysfs_close_device_tree((struct sysfs_device *)dev);
+ if (devroot) {
+ if (devroot->children) {
+ struct sysfs_device *child = NULL;
+
+ dlist_for_each_data(devroot->children, child,
+ struct sysfs_device) {
+ sysfs_close_device_tree(child);
+ }
+ }
+ sysfs_close_device(devroot);
+ }
}
/**
*/
void sysfs_close_device(struct sysfs_device *dev)
{
- if (dev != NULL) {
- if (dev->directory != NULL)
- sysfs_close_directory(dev->directory);
- if (dev->children != NULL && dev->children->count == 0)
+ if (dev) {
+ if (dev->parent)
+ sysfs_close_device(dev->parent);
+ if (dev->children && dev->children->count)
dlist_destroy(dev->children);
+ if (dev->attrlist)
+ dlist_destroy(dev->attrlist);
free(dev);
}
}
*/
static struct sysfs_device *alloc_device(void)
{
- return (struct sysfs_device *)calloc(1, sizeof(struct sysfs_device));
-}
-
-/**
- * sysfs_get_device_attr: searches dev's attributes by name
- * @dev: device to look through
- * @name: attribute name to get
- * returns sysfs_attribute reference with success or NULL with error.
- */
-struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
- const unsigned char *name)
-{
- struct sysfs_attribute *cur = NULL;
-
- if (dev == NULL || dev->directory == NULL
- || dev->directory->attributes == NULL || name == NULL) {
- errno = EINVAL;
- return NULL;
- }
-
- cur = sysfs_get_directory_attribute(dev->directory,
- (unsigned char *)name);
- if (cur != NULL)
- return cur;
-
- return NULL;
+ return (struct sysfs_device *) calloc(1, sizeof(struct sysfs_device));
}
/**
- * sysfs_open_device: opens and populates device structure
+ * sysfs_open_device_path: opens and populates device structure
* @path: path to device, this is the /sys/devices/ path
* returns sysfs_device structure with success or NULL with error
*/
-struct sysfs_device *sysfs_open_device(const unsigned char *path)
+struct sysfs_device *sysfs_open_device_path(const char *path)
{
- struct sysfs_device *dev = NULL;
- struct sysfs_directory *sdir = NULL;
+ struct sysfs_device *dev;
- if (path == NULL) {
+ if (!path) {
errno = EINVAL;
return NULL;
}
- dev = alloc_device();
- if (dev == NULL) {
+ if (sysfs_path_is_dir(path)) {
+ dprintf("Incorrect path to device: %s\n", path);
+ return NULL;
+ }
+ dev = alloc_device();
+ if (!dev) {
dprintf("Error allocating device at %s\n", path);
return NULL;
}
- sdir = sysfs_open_directory(path);
- if (sdir == NULL) {
- dprintf("Invalid device at %s\n", path);
+ if (sysfs_get_name_from_path(path, dev->bus_id, SYSFS_NAME_LEN)) {
errno = EINVAL;
+ dprintf("Error getting device bus_id\n");
sysfs_close_device(dev);
return NULL;
}
- if ((sysfs_read_directory(sdir)) != 0) {
- dprintf("Error reading device directory at %s\n", path);
- sysfs_close_directory(sdir);
+ safestrcpy(dev->path, path);
+ if (sysfs_remove_trailing_slash(dev->path)) {
+ dprintf("Invalid path to device %s\n", dev->path);
sysfs_close_device(dev);
return NULL;
}
- dev->directory = sdir;
- strcpy(dev->bus_id, sdir->name);
- strcpy(dev->path, sdir->path);
-
- /*
+ /*
* The "name" attribute no longer exists... return the device's
* sysfs representation instead, in the "dev->name" field, which
* implies that the dev->name and dev->bus_id contain same data.
*/
- strncpy(dev->name, sdir->name, SYSFS_NAME_LEN);
+ safestrcpy(dev->name, dev->bus_id);
- return dev;
-}
+ if (sysfs_get_device_bus(dev))
+ dprintf("Could not get device bus\n");
-/**
- * sysfs_open_device_tree: opens root device and all of its children,
- * creating a tree of devices. Only opens children.
- * @path: sysfs path to devices
- * returns struct sysfs_device and its children with success or NULL with
- * error.
- */
-static struct sysfs_device *sysfs_open_device_tree(const unsigned char *path)
-{
- struct sysfs_device *rootdev = NULL, *new = NULL;
- struct sysfs_directory *cur = NULL;
-
- if (path == NULL) {
- errno = EINVAL;
- return NULL;
- }
- rootdev = sysfs_open_device(path);
- if (rootdev == NULL) {
- dprintf("Error opening root device at %s\n", path);
- return NULL;
- }
- if (rootdev->directory->subdirs != NULL) {
- dlist_for_each_data(rootdev->directory->subdirs, cur,
- struct sysfs_directory) {
- new = sysfs_open_device_tree(cur->path);
- if (new == NULL) {
- dprintf("Error opening device tree at %s\n",
- cur->path);
- sysfs_close_device_tree(rootdev);
- return NULL;
- }
- if (rootdev->children == NULL)
- rootdev->children = dlist_new_with_delete
- (sizeof(struct sysfs_device),
- sysfs_del_device);
- dlist_unshift(rootdev->children, new);
- }
+ if (get_dev_driver(dev)) {
+ dprintf("Could not get device %s's driver\n", dev->bus_id);
+ safestrcpy(dev->driver_name, SYSFS_UNKNOWN);
}
- return rootdev;
-}
-
-/**
- * sysfs_close_root_device: closes root and all devices
- * @root: root device to close
- */
-void sysfs_close_root_device(struct sysfs_root_device *root)
-{
- if (root != NULL) {
- if (root->devices != NULL)
- dlist_destroy(root->devices);
- if (root->directory != NULL)
- sysfs_close_directory(root->directory);
- free(root);
- }
+ return dev;
}
/**
- * open_root_device_dir: opens up sysfs_directory for specific root dev
- * @name: name of root
- * returns struct sysfs_directory with success and NULL with error
+ * sysfs_get_device_attr: searches dev's attributes by name
+ * @dev: device to look through
+ * @name: attribute name to get
+ * returns sysfs_attribute reference with success or NULL with error.
*/
-static struct sysfs_directory *open_root_device_dir(const unsigned char *name)
+struct sysfs_attribute *sysfs_get_device_attr(struct sysfs_device *dev,
+ const char *name)
{
- struct sysfs_directory *rdir = NULL;
- unsigned char rootpath[SYSFS_PATH_MAX];
-
- if (name == NULL) {
+ if (!dev || !name) {
errno = EINVAL;
return NULL;
}
-
- memset(rootpath, 0, SYSFS_PATH_MAX);
- if (sysfs_get_mnt_path(rootpath, SYSFS_PATH_MAX) != 0) {
- dprintf ("Sysfs not supported on this system\n");
- return NULL;
- }
-
- strcat(rootpath, SYSFS_DEVICES_DIR);
- strcat(rootpath, "/");
- strcat(rootpath, name);
- rdir = sysfs_open_directory(rootpath);
- if (rdir == NULL) {
- errno = EINVAL;
- dprintf ("Root device %s not supported on this system\n",
- name);
- return NULL;
- }
- if (sysfs_read_directory(rdir) != 0) {
- dprintf ("Error reading %s root device at dir %s\n", name,
- rootpath);
- sysfs_close_directory(rdir);
- return NULL;
- }
-
- return rdir;
+ return get_attribute(dev, (char *)name);
}
/**
- * get_all_root_devices: opens up all the devices under this root device
- * @root: root device to open devices for
- * returns 0 with success and -1 with error
+ * sysfs_get_device_attributes: gets list of device attributes
+ * @dev: device whose attributes list is needed
+ * returns dlist of attributes on success or NULL on error
*/
-static int get_all_root_devices(struct sysfs_root_device *root)
+struct dlist *sysfs_get_device_attributes(struct sysfs_device *dev)
{
- struct sysfs_device *dev = NULL;
- struct sysfs_directory *cur = NULL;
-
- if (root == NULL || root->directory == NULL) {
+ if (!dev) {
errno = EINVAL;
- return -1;
- }
- if (root->directory->subdirs == NULL)
- return 0;
-
- dlist_for_each_data(root->directory->subdirs, cur,
- struct sysfs_directory) {
- dev = sysfs_open_device_tree(cur->path);
- if (dev == NULL) {
- dprintf ("Error opening device at %s\n", cur->path);
- continue;
- }
- if (root->devices == NULL)
- root->devices = dlist_new_with_delete
- (sizeof(struct sysfs_device),
- sysfs_close_dev_tree);
- dlist_unshift(root->devices, dev);
+ return NULL;
}
-
- return 0;
+ return get_attributes_list(dev);
}
/**
- * sysfs_open_root_device: opens sysfs devices root and all of its
- * devices.
- * @name: name of /sys/devices/root to open
- * returns struct sysfs_root_device if success and NULL with error
+ * get_device_absolute_path: looks up the bus the device is on, gets
+ * absolute path to the device
+ * @device: device for which path is needed
+ * @path: buffer to store absolute path
+ * @psize: size of "path"
+ * Returns 0 on success -1 on failure
*/
-struct sysfs_root_device *sysfs_open_root_device(const unsigned char *name)
+static int get_device_absolute_path(const char *device, const char *bus,
+ char *path, size_t psize)
{
- struct sysfs_root_device *root = NULL;
- struct sysfs_directory *rootdir = NULL;
+ char bus_path[SYSFS_PATH_MAX];
- if (name == NULL) {
+ if (!device || !path) {
errno = EINVAL;
- return NULL;
+ return -1;
}
- root = (struct sysfs_root_device *)calloc
- (1, sizeof(struct sysfs_root_device));
- if (root == NULL) {
- dprintf("calloc failure\n");
- return NULL;
- }
- rootdir = open_root_device_dir(name);
- if (rootdir == NULL) {
- dprintf ("Invalid root device, %s not supported\n", name);
- sysfs_close_root_device(root);
- return NULL;
+ memset(bus_path, 0, SYSFS_PATH_MAX);
+ if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX)) {
+ dprintf ("Sysfs not supported on this system\n");
+ return -1;
}
- strcpy(root->path, rootdir->path);
- root->directory = rootdir;
- if (get_all_root_devices(root) != 0) {
- dprintf ("Error retrieving devices for root %s\n", name);
- sysfs_close_root_device(root);
- return NULL;
+ safestrcat(bus_path, "/");
+ safestrcat(bus_path, SYSFS_BUS_NAME);
+ safestrcat(bus_path, "/");
+ safestrcat(bus_path, bus);
+ safestrcat(bus_path, "/");
+ safestrcat(bus_path, SYSFS_DEVICES_NAME);
+ safestrcat(bus_path, "/");
+ safestrcat(bus_path, device);
+ /*
+ * We now are at /sys/bus/"bus_name"/devices/"device" which is a link.
+ * Now read this link to reach to the device.
+ */
+ if (sysfs_get_link(bus_path, path, psize)) {
+ dprintf("Error getting to device %s\n", device);
+ return -1;
}
-
- return root;
-}
-
-/**
- * sysfs_get_device_attributes: returns a dlist of attributes corresponding to
- * the specific device
- * @device: struct sysfs_device * for which attributes are to be returned
- */
-struct dlist *sysfs_get_device_attributes(struct sysfs_device *device)
-{
- if (device == NULL || device->directory == NULL)
- return NULL;
-
- return (device->directory->attributes);
+ return 0;
}
/**
- * sysfs_open_device_by_id: open a device by id (use the "bus" subsystem)
+ * sysfs_open_device: open a device by id (use the "bus" subsystem)
+ * @bus: bus the device belongs to
* @bus_id: bus_id of the device to open - has to be the "bus_id" in
* /sys/bus/xxx/devices
- * @bus: bus the device belongs to
- * @bsize: size of the bus buffer
* returns struct sysfs_device if found, NULL otherwise
* NOTE:
* 1. Use sysfs_close_device to close the device
* 2. Bus the device is on must be supplied
* Use sysfs_find_device_bus to get the bus name
*/
-struct sysfs_device *sysfs_open_device_by_id(const unsigned char *bus_id,
- const unsigned char *bus, size_t bsize)
+struct sysfs_device *sysfs_open_device(const char *bus, const char *bus_id)
{
- char sysfs_path[SYSFS_PATH_MAX], device_path[SYSFS_PATH_MAX];
- struct sysfs_device *device = NULL;
+ char sysfs_path[SYSFS_PATH_MAX];
+ struct sysfs_device *device;
- if (bus_id == NULL || bus == NULL) {
+ if (!bus_id || !bus) {
errno = EINVAL;
return NULL;
}
memset(sysfs_path, 0, SYSFS_PATH_MAX);
- if ((sysfs_get_mnt_path(sysfs_path, SYSFS_PATH_MAX)) != 0) {
- dprintf("Error getting sysfs mount path\n");
- return NULL;
- }
- strcat(sysfs_path, SYSFS_BUS_DIR);
- strcat(sysfs_path, "/");
- strncat(sysfs_path, bus, bsize);
- strcat(sysfs_path, SYSFS_DEVICES_DIR);
- strcat(sysfs_path, "/");
- strcat(sysfs_path, bus_id);
-
- /* devices under /sys/bus/xxx/devices are links to devices subsystem */
- if ((sysfs_get_link(sysfs_path, device_path, SYSFS_PATH_MAX)) < 0) {
- dprintf("Error getting device path\n");
+ if (get_device_absolute_path(bus_id, bus, sysfs_path,
+ SYSFS_PATH_MAX)) {
+ dprintf("Error getting to device %s\n", bus_id);
return NULL;
}
- device = sysfs_open_device(device_path);
- if (device == NULL) {
+ device = sysfs_open_device_path(sysfs_path);
+ if (!device) {
dprintf("Error opening device %s\n", bus_id);
return NULL;
}
}
/**
- * get_device_absolute_path: looks up the bus the device is on, gets
- * absolute path to the device
- * @device: device for which path is needed
- * @path: buffer to store absolute path
- * @psize: size of "path"
- * Returns 0 on success -1 on failure
+ * sysfs_get_device_parent: opens up given device's parent and returns a
+ * reference to its sysfs_device
+ * @dev: sysfs_device whose parent is requested
+ * Returns sysfs_device of the parent on success and NULL on failure
*/
-static int get_device_absolute_path(const unsigned char *device,
- unsigned char *path, size_t psize)
+struct sysfs_device *sysfs_get_device_parent(struct sysfs_device *dev)
{
- unsigned char bus_name[SYSFS_NAME_LEN], bus_path[SYSFS_PATH_MAX];
+ char ppath[SYSFS_PATH_MAX], *tmp;
- if (device == NULL || path == NULL) {
+ if (!dev) {
errno = EINVAL;
- return -1;
- }
-
- memset(bus_name, 0, SYSFS_NAME_LEN);
- memset(bus_path, 0, SYSFS_NAME_LEN);
- if ((sysfs_find_device_bus(device, bus_name, SYSFS_NAME_LEN)) != 0) {
- dprintf("Device %s not found\n", device);
- return -1;
- }
- if (sysfs_get_mnt_path(bus_path, SYSFS_PATH_MAX) != 0) {
- dprintf ("Sysfs not supported on this system\n");
- return -1;
- }
- strcat(bus_path, SYSFS_BUS_DIR);
- strcat(bus_path, "/");
- strcat(bus_path, bus_name);
- strcat(bus_path, SYSFS_DEVICES_DIR);
- strcat(bus_path, "/");
- strcat(bus_path, device);
- /*
- * We now are at /sys/bus/"bus_name"/devices/"device" which is a link.
- * Now read this link to reach to the device.
- */
- if ((sysfs_get_link(bus_path, path, SYSFS_PATH_MAX)) != 0) {
- dprintf("Error getting to device %s\n", device);
- return -1;
+ return NULL;
}
- return 0;
-}
-/**
- * sysfs_write_device_attr: modify a "writable" attribute for the given device
- * @dev: device bus_id for which attribute has to be changed
- * @attrib: attribute to change
- * @value: value to change to
- * @len: "value" length to write
- * Returns 0 on success -1 on error
- */
-int sysfs_write_device_attr(unsigned char *dev, unsigned char *attrib,
- unsigned char *value, size_t len)
-{
- struct sysfs_attribute *attribute = NULL;
- unsigned char devpath[SYSFS_PATH_MAX];
+ if (dev->parent)
+ return (dev->parent);
- if (dev == NULL || attrib == NULL || value == NULL) {
- errno = EINVAL;
- return -1;
- }
-
- memset(devpath, 0, SYSFS_PATH_MAX);
- if ((get_device_absolute_path(dev, devpath, SYSFS_PATH_MAX)) != 0) {
- dprintf("Error finding absolute path to device %s\n", dev);
- return -1;
- }
- strcat(devpath, "/");
- strcat(devpath, attrib);
- attribute = sysfs_open_attribute(devpath);
- if (attribute == NULL) {
- dprintf("Attribute %s could not be retrieved for device %s\n",
- attrib, dev);
- return -1;
+ memset(ppath, 0, SYSFS_PATH_MAX);
+ safestrcpy(ppath, dev->path);
+ tmp = strrchr(ppath, '/');
+ if (!tmp) {
+ dprintf("Invalid path to device %s\n", ppath);
+ return NULL;
}
- if (attribute->method & SYSFS_METHOD_SHOW) {
- if ((sysfs_read_attribute(attribute)) != 0) {
- dprintf("Error reading attribute %s for device %s\n",
- attrib, dev);
- sysfs_close_attribute(attribute);
- return -1;
+ if (*(tmp + 1) == '\0') {
+ *tmp = '\0';
+ tmp = strrchr(tmp, '/');
+ if (tmp == NULL) {
+ dprintf("Invalid path to device %s\n", ppath);
+ return NULL;
}
}
- if ((sysfs_write_attribute(attribute, value, len)) < 0) {
- dprintf("Error setting %s to %s\n", attrib, value);
- sysfs_close_attribute(attribute);
- return -1;
- }
- sysfs_close_attribute(attribute);
- return 0;
-}
+ *tmp = '\0';
-/**
- * sysfs_read_device_attr: read an attribute of the given device
- * @dev: device bus_id for which attribute has to be changed
- * @attrib: attribute to read
- * @value: buffer to return value in
- * @len: size of buffer available
- * Returns 0 on success -1 on error
- */
-int sysfs_read_device_attr(unsigned char *dev, unsigned char *attrib,
- unsigned char *value, size_t len)
-{
- struct sysfs_attribute *attribute = NULL;
- unsigned char devpath[SYSFS_PATH_MAX];
-
- if (dev == NULL || attrib == NULL || value == NULL) {
- errno = EINVAL;
- return -1;
- }
-
- memset(devpath, 0, SYSFS_PATH_MAX);
- if ((get_device_absolute_path(dev, devpath, SYSFS_PATH_MAX)) != 0) {
- dprintf("Error finding absolute path to device %s\n", dev);
- return -1;
- }
- strcat(devpath, "/");
- strcat(devpath, attrib);
- attribute = sysfs_open_attribute(devpath);
- if (attribute == NULL) {
- dprintf("Error opening attribute %s for device %s\n",
- attrib, dev);
- return -1;
- }
- if (!(attribute->method & SYSFS_METHOD_SHOW)) {
- dprintf("Show method not supported for attribute %s\n",
- attrib);
- sysfs_close_attribute(attribute);
- return -1;
- }
- if ((sysfs_read_attribute(attribute)) != 0) {
- dprintf("Error reading attribute %s for device %s\n",
- attrib, dev);
- sysfs_close_attribute(attribute);
- return -1;
+ /*
+ * All "devices" have the "detach_state" attribute - validate here
+ */
+ safestrcat(ppath, "/detach_state");
+ if (sysfs_path_is_file(ppath)) {
+ dprintf("Device at %s does not have a parent\n", dev->path);
+ return NULL;
}
- if (attribute->len > len) {
- dprintf("Value length %d is larger than supplied buffer %d\n",
- attribute->len, len);
- sysfs_close_attribute(attribute);
- return -1;
+ tmp = strrchr(ppath, '/');
+ *tmp = '\0';
+ dev->parent = sysfs_open_device_path(ppath);
+ if (!dev->parent) {
+ dprintf("Error opening device %s's parent at %s\n",
+ dev->bus_id, ppath);
+ return NULL;
}
- strncpy(value, attribute->value, attribute->len);
- value[(attribute->len)+1] = 0;
- sysfs_close_attribute(attribute);
- return 0;
+ return (dev->parent);
}