// SPDX-License-Identifier: GPL-2.0
#include <linux/string.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/of.h>
#include <asm/prom.h>

#include "of_helpers.h"

/**
 * pseries_of_derive_parent - basically like dirname(1)
 * @path:  the full_name of a node to be added to the tree
 *
 * Returns the node which should be the parent of the node
 * described by path.  E.g., for path = "/foo/bar", returns
 * the node with full_name = "/foo".
 */
struct device_node *pseries_of_derive_parent(const char *path)
{
        struct device_node *parent;
        char *parent_path = "/";
        const char *tail;

        /* We do not want the trailing '/' character */
        tail = kbasename(path) - 1;

        /* reject if path is "/" */
        if (!strcmp(path, "/"))
                return ERR_PTR(-EINVAL);

        if (tail > path) {
                parent_path = kstrndup(path, tail - path, GFP_KERNEL);
                if (!parent_path)
                        return ERR_PTR(-ENOMEM);
        }
        parent = of_find_node_by_path(parent_path);
        if (strcmp(parent_path, "/"))
                kfree(parent_path);
        return parent ? parent : ERR_PTR(-EINVAL);
}


/* Helper Routines to convert between drc_index to cpu numbers */

int of_read_drc_info_cell(struct property **prop, const __be32 **curval,
                        struct of_drc_info *data)
{
        const char *p = (char *)(*curval);
        const __be32 *p2;

        if (!data)
                return -EINVAL;

        /* Get drc-type:encode-string */
        data->drc_type = (char *)p;
        p = of_prop_next_string(*prop, p);
        if (!p)
                return -EINVAL;

        /* Get drc-name-prefix:encode-string */
        data->drc_name_prefix = (char *)p;
        p = of_prop_next_string(*prop, p);
        if (!p)
                return -EINVAL;

        /* Get drc-index-start:encode-int */
        p2 = (const __be32 *)p;
        data->drc_index_start = be32_to_cpu(*p2);

        /* Get drc-name-suffix-start:encode-int */
        p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start);
        if (!p2)
                return -EINVAL;

        /* Get number-sequential-elements:encode-int */
        p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems);
        if (!p2)
                return -EINVAL;

        /* Get sequential-increment:encode-int */
        p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc);
        if (!p2)
                return -EINVAL;

        /* Get drc-power-domain:encode-int */
        p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain);
        if (!p2)
                return -EINVAL;

        /* Should now know end of current entry */
        (*curval) = (void *)(++p2);
        data->last_drc_index = data->drc_index_start +
                ((data->num_sequential_elems - 1) * data->sequential_inc);

        return 0;
}
EXPORT_SYMBOL(of_read_drc_info_cell);