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>
#include "of_private.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 platform_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 ((!matches) || (!dev->of_node))
return NULL;
return of_match_node(matches, dev->of_node);
}
EXPORT_SYMBOL(of_match_device);
struct platform_device *of_dev_get(struct platform_device *dev)
{
struct device *tmp;
if (!dev)
return NULL;
tmp = get_device(&dev->dev);
if (tmp)
return to_platform_device(tmp);
else
return NULL;
}
EXPORT_SYMBOL(of_dev_get);
void of_dev_put(struct platform_device *dev)
{
if (dev)
put_device(&dev->dev);
}
EXPORT_SYMBOL(of_dev_put);
int of_device_add(struct platform_device *ofdev)
{
BUG_ON(ofdev->dev.of_node == NULL);
/* name and id have to be set so that the platform bus doesn't get
* confused on matching */
ofdev->name = dev_name(&ofdev->dev);
ofdev->id = -1;
/* 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);
}
int of_device_register(struct platform_device *pdev)
{
device_initialize(&pdev->dev);
return of_device_add(pdev);
}
EXPORT_SYMBOL(of_device_register);
void of_device_unregister(struct platform_device *ofdev)
{
device_unregister(&ofdev->dev);
}
EXPORT_SYMBOL(of_device_unregister);
ssize_t of_device_get_modalias(struct device *dev, char *str, ssize_t len)
{
const char *compat;
int cplen, i;
ssize_t tsize, csize, repend;
if ((!dev) || (!dev->of_node))
return -ENODEV;
/* Name & Type */
csize = snprintf(str, len, "of:N%sT%s", dev->of_node->name,
dev->of_node->type);
/* Get compatible property if any */
compat = of_get_property(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;
}
/**
* of_device_uevent - Display OF related uevent information
*/
void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
const char *compat;
struct alias_prop *app;
int seen = 0, cplen, sl;
if ((!dev) || (!dev->of_node))
return;
add_uevent_var(env, "OF_NAME=%s", dev->of_node->name);
add_uevent_var(env, "OF_FULLNAME=%s", dev->of_node->full_name);
if (dev->of_node->type && strcmp("<NULL>", dev->of_node->type) != 0)
add_uevent_var(env, "OF_TYPE=%s", dev->of_node->type);
/* 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(dev->of_node, "compatible", &cplen);
while (compat && *compat && cplen > 0) {
add_uevent_var(env, "OF_COMPATIBLE_%d=%s", seen, compat);
sl = strlen(compat) + 1;
compat += sl;
cplen -= sl;
seen++;
}
add_uevent_var(env, "OF_COMPATIBLE_N=%d", seen);
seen = 0;
mutex_lock(&of_aliases_mutex);
list_for_each_entry(app, &aliases_lookup, link) {
if (dev->of_node == app->np) {
add_uevent_var(env, "OF_ALIAS_%d=%s", seen,
app->alias);
seen++;
}
}
mutex_unlock(&of_aliases_mutex);
}
int of_device_uevent_modalias(struct device *dev, struct kobj_uevent_env *env)
{
int sl;
if ((!dev) || (!dev->of_node))
return -ENODEV;
/* Devicetree modalias is tricky, we add it in 2 steps */
if (add_uevent_var(env, "MODALIAS="))
return -ENOMEM;
sl = of_device_get_modalias(dev, &env->buf[env->buflen-1],
sizeof(env->buf) - env->buflen);
if (sl >= (sizeof(env->buf) - env->buflen))
return -ENOMEM;
env->buflen += sl;
return 0;
}