1
linux/arch/powerpc/kernel/of_device.c

242 lines
5.5 KiB
C
Raw Normal View History

#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
#include <asm/errno.h>
#include <asm/of_device.h>
/**
* of_match_node - Tell if an device_node has a matching of_match structure
* @ids: array of of device match structures to search in
* @node: the of device structure to match against
*
* Low level utility function used by device matching.
*/
const struct of_device_id *of_match_node(const struct of_device_id *matches,
const struct device_node *node)
{
while (matches->name[0] || matches->type[0] || matches->compatible[0]) {
int match = 1;
if (matches->name[0])
match &= node->name
&& !strcmp(matches->name, node->name);
if (matches->type[0])
match &= node->type
&& !strcmp(matches->type, node->type);
if (matches->compatible[0])
match &= of_device_is_compatible(node,
matches->compatible);
if (match)
return matches;
matches++;
}
return NULL;
}
/**
* of_match_device - Tell if an of_device structure has a matching
* of_match structure
* @ids: array of of device match structures to search in
* @dev: the of device structure to match against
*
* Used by a driver to check whether an of_device present in the
* system is in its list of supported devices.
*/
const struct of_device_id *of_match_device(const struct of_device_id *matches,
const struct of_device *dev)
{
if (!dev->node)
return NULL;
return of_match_node(matches, dev->node);
}
struct of_device *of_dev_get(struct of_device *dev)
{
struct device *tmp;
if (!dev)
return NULL;
tmp = get_device(&dev->dev);
if (tmp)
return to_of_device(tmp);
else
return NULL;
}
void of_dev_put(struct of_device *dev)
{
if (dev)
put_device(&dev->dev);
}
static ssize_t dev_show_devspec(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct of_device *ofdev;
ofdev = to_of_device(dev);
return sprintf(buf, "%s", ofdev->node->full_name);
}
static DEVICE_ATTR(devspec, S_IRUGO, dev_show_devspec, NULL);
/**
* of_release_dev - free an of device structure when all users of it are finished.
* @dev: device that's been disconnected
*
* Will be called only by the device core when all users of this of device are
* done.
*/
void of_release_dev(struct device *dev)
{
struct of_device *ofdev;
ofdev = to_of_device(dev);
of_node_put(ofdev->node);
kfree(ofdev);
}
int of_device_register(struct of_device *ofdev)
{
int rc;
BUG_ON(ofdev->node == NULL);
rc = device_register(&ofdev->dev);
if (rc)
return rc;
return device_create_file(&ofdev->dev, &dev_attr_devspec);
}
void of_device_unregister(struct of_device *ofdev)
{
device_remove_file(&ofdev->dev, &dev_attr_devspec);
device_unregister(&ofdev->dev);
}
static ssize_t of_device_get_modalias(struct of_device *ofdev,
char *str, ssize_t len)
{
const char *compat;
int cplen, i;
ssize_t tsize, csize, repend;
/* Name & Type */
csize = snprintf(str, len, "of:N%sT%s",
ofdev->node->name, ofdev->node->type);
/* Get compatible property if any */
compat = of_get_property(ofdev->node, "compatible", &cplen);
if (!compat)
return csize;
/* Find true end (we tolerate multiple \0 at the end */
for (i=(cplen-1); i>=0 && !compat[i]; i--)
cplen--;
if (!cplen)
return csize;
cplen++;
/* Check space (need cplen+1 chars including final \0) */
tsize = csize + cplen;
repend = tsize;
if (csize>=len) /* @ the limit, all is already filled */
return tsize;
if (tsize>=len) { /* limit compat list */
cplen = len-csize-1;
repend = len;
}
/* Copy and do char replacement */
memcpy(&str[csize+1], compat, cplen);
for (i=csize; i<repend; i++) {
char c = str[i];
if (c=='\0')
str[i] = 'C';
else if (c==' ')
str[i] = '_';
}
return tsize;
}
int of_device_uevent(struct device *dev,
char **envp, int num_envp, char *buffer, int buffer_size)
{
struct of_device *ofdev;
const char *compat;
int i = 0, length = 0, seen = 0, cplen, sl;
if (!dev)
return -ENODEV;
ofdev = to_of_device(dev);
if (add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"OF_NAME=%s", ofdev->node->name))
return -ENOMEM;
if (add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"OF_TYPE=%s", ofdev->node->type))
return -ENOMEM;
/* Since the compatible field can contain pretty much anything
* it's not really legal to split it out with commas. We split it
* up using a number of environment variables instead. */
compat = of_get_property(ofdev->node, "compatible", &cplen);
while (compat && *compat && cplen > 0) {
if (add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"OF_COMPATIBLE_%d=%s", seen, compat))
return -ENOMEM;
sl = strlen (compat) + 1;
compat += sl;
cplen -= sl;
seen++;
}
if (add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"OF_COMPATIBLE_N=%d", seen))
return -ENOMEM;
/* modalias is trickier, we add it in 2 steps */
if (add_uevent_var(envp, num_envp, &i,
buffer, buffer_size, &length,
"MODALIAS="))
return -ENOMEM;
sl = of_device_get_modalias(ofdev, &buffer[length-1],
buffer_size-length);
if (sl >= (buffer_size-length))
return -ENOMEM;
length += sl;
envp[i] = NULL;
return 0;
}
EXPORT_SYMBOL(of_match_node);
EXPORT_SYMBOL(of_match_device);
EXPORT_SYMBOL(of_device_register);
EXPORT_SYMBOL(of_device_unregister);
EXPORT_SYMBOL(of_dev_get);
EXPORT_SYMBOL(of_dev_put);
EXPORT_SYMBOL(of_release_dev);
EXPORT_SYMBOL(of_device_uevent);