#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;

        /* 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;
}