device.c

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#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>

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;

    /* 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;
}

void of_device_uevent(struct device *dev, struct kobj_uevent_env *env)
{
    const char *compat;
    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);
}

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;
}