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 * alloc_driver: allocates and initializes driver
70 * returns struct sysfs_driver with success and NULL with error.
72 static struct sysfs_driver *alloc_driver(void)
74 return (struct sysfs_driver *)calloc(1, sizeof(struct sysfs_driver));
78 * sysfs_open_driver_path: opens and initializes driver structure
79 * @path: path to driver directory
80 * returns struct sysfs_driver with success and NULL with error
82 struct sysfs_driver *sysfs_open_driver_path(const unsigned char *path)
84 struct sysfs_driver *driver = NULL;
90 if ((sysfs_path_is_dir(path)) != 0) {
91 dprintf("Invalid path to driver: %s\n", path);
94 driver = alloc_driver();
96 dprintf("Error allocating driver at %s\n", path);
99 if ((sysfs_get_name_from_path(path, driver->name,
100 SYSFS_NAME_LEN)) != 0) {
101 dprintf("Error getting driver name from path\n");
105 strcpy(driver->path, path);
106 if ((sysfs_remove_trailing_slash(driver->path)) != 0) {
107 dprintf("Invalid path to driver %s\n", driver->path);
108 sysfs_close_driver(driver);
116 * sysfs_get_driver_attributes: gets list of attributes for the given driver
117 * @driver: sysfs_driver for which attributes are required
118 * returns a dlist of attributes corresponding to the driver if present
121 struct dlist *sysfs_get_driver_attributes(struct sysfs_driver *driver)
123 if (driver == NULL) {
128 if (driver->directory == NULL) {
129 if ((open_driver_dir(driver)) == 1)
132 if (driver->directory->attributes == NULL) {
133 if ((sysfs_read_dir_attributes(driver->directory)) != 0)
136 return(driver->directory->attributes);
140 * sysfs_refresh_driver_attributes: refreshes the driver's list of attributes
141 * @driver: sysfs_driver whose attributes to refresh
143 * NOTE: Upon return, prior references to sysfs_attributes for this driver
146 * Returns list of attributes on success and NULL on failure
148 struct dlist *sysfs_refresh_driver_attributes(struct sysfs_driver *driver)
150 if (driver == NULL) {
154 if (driver->directory == NULL)
155 return (sysfs_get_driver_attributes(driver));
157 if ((sysfs_refresh_dir_attributes(driver->directory)) != 0) {
158 dprintf("Error refreshing driver attributes\n");
161 return (driver->directory->attributes);
165 * sysfs_get_driver_attr: searches driver's attributes by name
166 * @drv: driver to look through
167 * @name: attribute name to get
168 * returns sysfs_attribute reference on success or NULL with error
170 struct sysfs_attribute *sysfs_get_driver_attr(struct sysfs_driver *drv,
171 const unsigned char *name)
173 struct dlist *attrlist = NULL;
180 attrlist = sysfs_get_driver_attributes(drv);
181 if (attrlist != NULL)
184 return sysfs_get_directory_attribute(drv->directory,
185 (unsigned char *)name);
189 * sysfs_get_driver_links: gets list of links from the given driver
190 * @driver: sysfs_driver for which links list is required
191 * returns a dlist of links corresponding to the driver if present
194 struct dlist *sysfs_get_driver_links(struct sysfs_driver *driver)
196 if (driver == NULL) {
200 if (driver->directory == NULL) {
201 if ((open_driver_dir(driver)) == 1)
203 if ((sysfs_read_dir_links(driver->directory)) != 0)
206 return(driver->directory->links);
210 * sysfs_get_driver_devices: open up the list of devices this driver supports
211 * @driver: sysfs_driver for which devices are needed
212 * Returns dlist of devices on SUCCESS or NULL with ERROR
214 struct dlist *sysfs_get_driver_devices(struct sysfs_driver *driver)
216 struct sysfs_link *curlink = NULL;
217 struct sysfs_device *device = NULL;
219 if (driver == NULL) {
224 if (driver->devices != NULL)
225 return (driver->devices);
227 if (driver->directory == NULL) {
228 if ((open_driver_dir(driver)) == 1)
230 if ((sysfs_read_dir_links(driver->directory)) != 0)
233 if (driver->directory->links != NULL) {
234 dlist_for_each_data(driver->directory->links, curlink,
236 device = sysfs_open_device_path(curlink->target);
237 if (device == NULL) {
238 dprintf("Error opening device at %s\n",
242 strcpy(device->driver_name, driver->name);
243 if (driver->devices == NULL)
244 driver->devices = dlist_new_with_delete
245 (sizeof(struct sysfs_device),
246 sysfs_close_driver_device);
247 dlist_unshift(driver->devices, device);
250 return (driver->devices);
254 * sysfs_refresh_driver_devices: Refreshes drivers list of devices
255 * @driver: sysfs_driver whose devices list needs to be refreshed
257 * NOTE: Upon return from this function, prior sysfs_device references from
258 * this driver's list of devices _may_ not be valid
260 * Returns dlist of devices on success and NULL on failure
262 struct dlist *sysfs_refresh_driver_devices(struct sysfs_driver *driver)
264 if (driver == NULL) {
269 if (driver->devices != NULL) {
270 dlist_destroy(driver->devices);
271 driver->devices = NULL;
274 if (driver->directory == NULL)
275 return (sysfs_get_driver_devices(driver));
277 if ((sysfs_refresh_dir_links(driver->directory)) != 0) {
278 dprintf("Error refreshing driver links\n");
282 return (sysfs_get_driver_devices(driver));
286 * sysfs_get_driver_device: looks up a device from a list of driver's devices
287 * and returns its sysfs_device corresponding to it
288 * @driver: sysfs_driver on which to search
289 * @name: name of the device to search
290 * Returns a sysfs_device if found, NULL otherwise
292 struct sysfs_device *sysfs_get_driver_device(struct sysfs_driver *driver,
293 const unsigned char *name)
295 struct sysfs_device *device = NULL;
296 struct dlist *devlist = NULL;
298 if (driver == NULL || name == NULL) {
303 if (driver->devices == NULL) {
304 devlist = sysfs_get_driver_devices(driver);
305 if (devlist == NULL) {
306 dprintf("Error getting driver devices\n");
310 dlist_for_each_data(driver->devices, device, struct sysfs_device) {
311 if (!(strncmp(device->name, name, SYSFS_NAME_LEN)))
318 * get_driver_path: looks up the bus the driver is on and builds path to
320 * @bus: bus on which to search
321 * @drv: driver to look for
322 * @path: buffer to return path to driver
323 * @psize: size of "path"
324 * Returns 0 on success and -1 on error
326 static int get_driver_path(const unsigned char *bus,
327 const unsigned char *drv, unsigned char *path, size_t psize)
329 if (bus == NULL || drv == NULL || path == NULL) {
333 if (sysfs_get_mnt_path(path, psize) != 0) {
334 dprintf("Error getting sysfs mount path\n");
338 strcat(path, SYSFS_BUS_NAME);
342 strcat(path, SYSFS_DRIVERS_NAME);
349 * sysfs_open_driver_attr: read the user supplied driver attribute
350 * @bus: bus on which to look
351 * @drv: driver whose attribute has to be read
352 * @attrib: Attribute to be read
353 * Returns struct sysfs_attribute on success and NULL on failure
356 * A call to sysfs_close_attribute() is required to close the
357 * attribute returned and to free memory
359 struct sysfs_attribute *sysfs_open_driver_attr(const unsigned char *bus,
360 const unsigned char *drv, const unsigned char *attrib)
362 struct sysfs_attribute *attribute = NULL;
363 unsigned char path[SYSFS_PATH_MAX];
365 if (bus == NULL || drv == NULL || attrib == NULL) {
370 memset(path, 0, SYSFS_PATH_MAX);
371 if ((get_driver_path(bus, drv, path, SYSFS_PATH_MAX)) != 0) {
372 dprintf("Error getting to driver %s\n", drv);
376 strcat(path, attrib);
377 attribute = sysfs_open_attribute(path);
378 if (attribute == NULL) {
379 dprintf("Error opening attribute %s for driver %s\n",
383 if ((sysfs_read_attribute(attribute)) != 0) {
384 dprintf("Error reading attribute %s for driver %s\n",
386 sysfs_close_attribute(attribute);
393 * sysfs_open_driver: open driver by name, given its bus
394 * @drv_name: Name of the driver
395 * @bus_name: Name of the bus
396 * Returns the sysfs_driver reference on success and NULL on failure
398 struct sysfs_driver *sysfs_open_driver(const unsigned char *drv_name,
399 const unsigned char *bus_name)
401 unsigned char path[SYSFS_PATH_MAX];
402 struct sysfs_driver *driver = NULL;
404 if (drv_name == NULL || bus_name == NULL) {
409 memset(path, 0, SYSFS_PATH_MAX);
410 if ((get_driver_path(bus_name, drv_name, path, SYSFS_PATH_MAX)) != 0) {
411 dprintf("Error getting to driver %s\n", drv_name);
414 driver = sysfs_open_driver_path(path);
415 if (driver == NULL) {
416 dprintf("Error opening driver at %s\n", path);