LXR linux/arch/powerpc/platforms/pseries/of

   1// SPDX-License-Identifier: GPL-2.0
   2#include <linux/string.h>
   3#include <linux/err.h>
   4#include <linux/slab.h>
   5#include <linux/of.h>
   6#include <asm/prom.h>
   7
   8#include "of_helpers.h"
   9
  10/**
  11 * pseries_of_derive_parent - basically like dirname(1)
  12 * @path:  the full_name of a node to be added to the tree
  13 *
  14 * Returns the node which should be the parent of the node
  15 * described by path.  E.g., for path = "/foo/bar", returns
  16 * the node with full_name = "/foo".
  17 */
  18struct device_node *pseries_of_derive_parent(const char *path)
  19{
  20        struct device_node *parent;
  21        char *parent_path = "/";
  22        const char *tail;
  23
  24        /* We do not want the trailing '/' character */
  25        tail = kbasename(path) - 1;
  26
  27        /* reject if path is "/" */
  28        if (!strcmp(path, "/"))
  29                return ERR_PTR(-EINVAL);
  30
  31        if (tail > path) {
  32                parent_path = kstrndup(path, tail - path, GFP_KERNEL);
  33                if (!parent_path)
  34                        return ERR_PTR(-ENOMEM);
  35        }
  36        parent = of_find_node_by_path(parent_path);
  37        if (strcmp(parent_path, "/"))
  38                kfree(parent_path);
  39        return parent ? parent : ERR_PTR(-EINVAL);
  40}
  41
  42
  43/* Helper Routines to convert between drc_index to cpu numbers */
  44
  45int of_read_drc_info_cell(struct property **prop, const __be32 **curval,
  46                        struct of_drc_info *data)
  47{
  48        const char *p = (char *)(*curval);
  49        const __be32 *p2;
  50
  51        if (!data)
  52                return -EINVAL;
  53
  54        /* Get drc-type:encode-string */
  55        data->drc_type = (char *)p;
  56        p = of_prop_next_string(*prop, p);
  57        if (!p)
  58                return -EINVAL;
  59
  60        /* Get drc-name-prefix:encode-string */
  61        data->drc_name_prefix = (char *)p;
  62        p = of_prop_next_string(*prop, p);
  63        if (!p)
  64                return -EINVAL;
  65
  66        /* Get drc-index-start:encode-int */
  67        p2 = (const __be32 *)p;
  68        data->drc_index_start = be32_to_cpu(*p2);
  69
  70        /* Get drc-name-suffix-start:encode-int */
  71        p2 = of_prop_next_u32(*prop, p2, &data->drc_name_suffix_start);
  72        if (!p2)
  73                return -EINVAL;
  74
  75        /* Get number-sequential-elements:encode-int */
  76        p2 = of_prop_next_u32(*prop, p2, &data->num_sequential_elems);
  77        if (!p2)
  78                return -EINVAL;
  79
  80        /* Get sequential-increment:encode-int */
  81        p2 = of_prop_next_u32(*prop, p2, &data->sequential_inc);
  82        if (!p2)
  83                return -EINVAL;
  84
  85        /* Get drc-power-domain:encode-int */
  86        p2 = of_prop_next_u32(*prop, p2, &data->drc_power_domain);
  87        if (!p2)
  88                return -EINVAL;
  89
  90        /* Should now know end of current entry */
  91        (*curval) = (void *)(++p2);
  92        data->last_drc_index = data->drc_index_start +
  93                ((data->num_sequential_elems - 1) * data->sequential_inc);
  94
  95        return 0;
  96}
  97EXPORT_SYMBOL(of_read_drc_info_cell);
  98