device.c
#include <linux/string.h>
#include <linux/kernel.h>
#include <linux/of.h>
#include <linux/of_device.h>
#include <linux/init.h>
#include <linux/module.h>
#include <linux/mod_devicetable.h>
#include <linux/slab.h>
#include <asm/errno.h>
/**
* of_match_device - Tell if a struct device matches an of_device_id list
* @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 device *dev)
{
if (!dev->of_node)
return NULL;
return of_match_node(matches, dev->of_node);
}
EXPORT_SYMBOL(of_match_device);
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;
}
EXPORT_SYMBOL(of_dev_get);
void of_dev_put(struct of_device *dev)
{
if (dev)
put_device(&dev->dev);
}
EXPORT_SYMBOL(of_dev_put);
static ssize_t devspec_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct of_device *ofdev;
ofdev = to_of_device(dev);
return sprintf(buf, "%s\n", ofdev->dev.of_node->full_name);
}
static ssize_t name_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct of_device *ofdev;
ofdev = to_of_device(dev);
return sprintf(buf, "%s\n", ofdev->dev.of_node->name);
}
static ssize_t modalias_show(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct of_device *ofdev = to_of_device(dev);
ssize_t len = 0;
len = of_device_get_modalias(ofdev, buf, PAGE_SIZE - 2);
buf[len] = '\n';
buf[len+1] = 0;
return len+1;
}
struct device_attribute of_platform_device_attrs[] = {
__ATTR_RO(devspec),
__ATTR_RO(name),
__ATTR_RO(modalias),
__ATTR_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->dev.of_node);
kfree(ofdev);
}
EXPORT_SYMBOL(of_release_dev);
int of_device_register(struct of_device *ofdev)
{
BUG_ON(ofdev->dev.of_node == NULL);
device_initialize(&ofdev->dev);
/* device_add will assume that this device is on the same node as
* the parent. If there is no parent defined, set the node
* explicitly */
if (!ofdev->dev.parent)
set_dev_node(&ofdev->dev, of_node_to_nid(ofdev->dev.of_node));
return device_add(&ofdev->dev);
}
EXPORT_SYMBOL(of_device_register);
void of_device_unregister(struct of_device *ofdev)
{
device_unregister(&ofdev->dev);
}
EXPORT_SYMBOL(of_device_unregister);
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->dev.of_node->name,
ofdev->dev.of_node->type);
/* Get compatible property if any */
compat = of_get_property(ofdev->dev.of_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;
}