4 * Driver utility functions for libsysfs
6 * Copyright (C) IBM Corp. 2003
8 * This library is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * This library is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with this library; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
26 static void sysfs_close_driver_device(void *device)
28 sysfs_close_device((struct sysfs_device *)device);
32 * sysfs_close_driver: closes driver and deletes device lists too
33 * @driver: driver to close
35 void sysfs_close_driver(struct sysfs_driver *driver)
38 if (driver->devices != NULL)
39 dlist_destroy(driver->devices);
40 if (driver->directory != NULL)
41 sysfs_close_directory(driver->directory);
47 * open_driver_dir: Open the sysfs_directory for this driver
48 * @driver: Driver whose directory to be opened
49 * Returns 0 on success and 1 on failure
51 static int open_driver_dir(struct sysfs_driver *driver)
57 if (driver->directory == NULL) {
58 driver->directory = sysfs_open_directory(driver->path);
59 if (driver->directory == NULL) {
60 dprintf("Error opening driver directory at %s\n",
69 * read_driver_dir: Read driver directory's subdirs and links
70 * @driver: Driver to read
71 * Returns 0 on success and 1 on failure
73 static int read_driver_dir(struct sysfs_driver *driver)
79 if (driver->directory == NULL) {
80 if ((open_driver_dir(driver)) == 1)
83 if ((sysfs_read_directory(driver->directory)) != 0) {
84 dprintf("Error reading driver directory at %s\n",
92 * alloc_driver: allocates and initializes driver
93 * returns struct sysfs_driver with success and NULL with error.
95 static struct sysfs_driver *alloc_driver(void)
97 return (struct sysfs_driver *)calloc(1, sizeof(struct sysfs_driver));
101 * sysfs_open_driver: opens and initializes driver structure
102 * @path: path to driver directory
103 * returns struct sysfs_driver with success and NULL with error
105 struct sysfs_driver *sysfs_open_driver(const unsigned char *path)
107 struct sysfs_driver *driver = NULL;
113 if ((sysfs_path_is_dir(path)) != 0) {
114 dprintf("Invalid path to driver: %s\n", path);
117 driver = alloc_driver();
118 if (driver == NULL) {
119 dprintf("Error allocating driver at %s\n", path);
122 if ((sysfs_get_name_from_path(path, driver->name,
123 SYSFS_NAME_LEN)) != 0) {
124 dprintf("Error getting driver name from path\n");
128 strcpy(driver->path, path);
134 * sysfs_get_driver_attributes: gets list of attributes for the given driver
135 * @driver: sysfs_driver for which attributes are required
136 * returns a dlist of attributes corresponding to the driver if present
139 struct dlist *sysfs_get_driver_attributes(struct sysfs_driver *driver)
141 if (driver == NULL) {
146 if (driver->directory == NULL) {
147 if ((open_driver_dir(driver)) == 1)
150 if (driver->directory->attributes == NULL) {
151 if ((sysfs_read_dir_attributes(driver->directory)) != 0) {
152 dprintf("Error reading driver attributes\n");
156 if ((sysfs_path_is_dir(driver->path)) != 0) {
157 dprintf("Driver at %s no longer exists\n",
161 if ((sysfs_refresh_attributes
162 (driver->directory->attributes)) != 0) {
163 dprintf("Error refreshing driver attributes\n");
167 return(driver->directory->attributes);
171 * sysfs_get_driver_attr: searches driver's attributes by name
172 * @drv: driver to look through
173 * @name: attribute name to get
174 * returns sysfs_attribute reference on success or NULL with error
176 struct sysfs_attribute *sysfs_get_driver_attr(struct sysfs_driver *drv,
177 const unsigned char *name)
179 struct sysfs_attribute *cur = NULL;
180 struct dlist *attrlist = NULL;
187 attrlist = sysfs_get_driver_attributes(drv);
188 if (attrlist != NULL) {
189 cur = sysfs_get_directory_attribute(drv->directory,
190 (unsigned char *)name);
198 * sysfs_get_driver_links: gets list of links from the given driver
199 * @driver: sysfs_driver for which links list is required
200 * returns a dlist of links corresponding to the driver if present
203 struct dlist *sysfs_get_driver_links(struct sysfs_driver *driver)
205 if (driver == NULL) {
209 if (driver->directory == NULL) {
210 if ((open_driver_dir(driver)) == 1)
212 if ((read_driver_dir(driver)) != 0)
215 return(driver->directory->links);
219 * sysfs_get_driver_devices: open up the list of devices this driver supports
220 * @driver: sysfs_driver for which devices are needed
221 * Returns dlist of devices on SUCCESS or NULL with ERROR
223 struct dlist *sysfs_get_driver_devices(struct sysfs_driver *driver)
225 struct sysfs_link *curlink = NULL;
226 struct sysfs_device *device = NULL;
228 if (driver == NULL) {
233 if (driver->devices != NULL)
234 return (driver->devices);
236 if (driver->directory == NULL) {
237 if ((open_driver_dir(driver)) == 1)
239 if ((read_driver_dir(driver)) != 0)
242 if (driver->directory->links != NULL) {
243 dlist_for_each_data(driver->directory->links, curlink,
245 device = sysfs_open_device(curlink->target);
246 if (device == NULL) {
247 dprintf("Error opening device at %s\n",
251 strcpy(device->driver_name, driver->name);
252 if (driver->devices == NULL)
253 driver->devices = dlist_new_with_delete
254 (sizeof(struct sysfs_device),
255 sysfs_close_driver_device);
256 dlist_unshift(driver->devices, device);
259 return (driver->devices);
263 * sysfs_get_driver_device: looks up a device from a list of driver's devices
264 * and returns its sysfs_device corresponding to it
265 * @driver: sysfs_driver on which to search
266 * @name: name of the device to search
267 * Returns a sysfs_device if found, NULL otherwise
269 struct sysfs_device *sysfs_get_driver_device(struct sysfs_driver *driver,
270 const unsigned char *name)
272 struct sysfs_device *device = NULL;
273 struct dlist *devlist = NULL;
275 if (driver == NULL || name == NULL) {
280 if (driver->devices == NULL) {
281 devlist = sysfs_get_driver_devices(driver);
282 if (devlist == NULL) {
283 dprintf("Error getting driver devices\n");
287 dlist_for_each_data(driver->devices, device, struct sysfs_device) {
288 if (!(strncmp(device->name, name, SYSFS_NAME_LEN)))
295 * get_driver_path: looks up the bus the driver is on and builds path to
297 * @bus: bus on which to search
298 * @drv: driver to look for
299 * @path: buffer to return path to driver
300 * @psize: size of "path"
301 * Returns 0 on success and -1 on error
303 static int get_driver_path(const unsigned char *bus,
304 const unsigned char *drv, unsigned char *path, size_t psize)
306 if (bus == NULL || drv == NULL || path == NULL) {
310 if (sysfs_get_mnt_path(path, psize) != 0) {
311 dprintf("Error getting sysfs mount path\n");
314 if (sysfs_trailing_slash(path) == 0)
316 strcat(path, SYSFS_BUS_NAME);
320 strcat(path, SYSFS_DRIVERS_NAME);
327 * sysfs_open_driver_attr: read the user supplied driver attribute
328 * @bus: bus on which to look
329 * @drv: driver whose attribute has to be read
330 * @attrib: Attribute to be read
331 * Returns struct sysfs_attribute on success and NULL on failure
334 * A call to sysfs_close_attribute() is required to close the
335 * attribute returned and to free memory
337 struct sysfs_attribute *sysfs_open_driver_attr(const unsigned char *bus,
338 const unsigned char *drv, const unsigned char *attrib)
340 struct sysfs_attribute *attribute = NULL;
341 unsigned char path[SYSFS_PATH_MAX];
343 if (bus == NULL || drv == NULL || attrib == NULL) {
348 memset(path, 0, SYSFS_NAME_LEN);
349 if ((get_driver_path(bus, drv, path, SYSFS_PATH_MAX)) != 0) {
350 dprintf("Error getting to driver %s\n", drv);
354 strcat(path, attrib);
355 attribute = sysfs_open_attribute(path);
356 if (attribute == NULL) {
357 dprintf("Error opening attribute %s for driver %s\n",
361 if ((sysfs_read_attribute(attribute)) != 0) {
362 dprintf("Error reading attribute %s for driver %s\n",
364 sysfs_close_attribute(attribute);