LXR linux/net/wireless/of.c

   1/*
   2 * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
   3 *
   4 * Permission to use, copy, modify, and/or distribute this software for any
   5 * purpose with or without fee is hereby granted, provided that the above
   6 * copyright notice and this permission notice appear in all copies.
   7 *
   8 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15 */
  16
  17#include <linux/of.h>
  18#include <net/cfg80211.h>
  19#include "core.h"
  20
  21static bool wiphy_freq_limits_valid_chan(struct wiphy *wiphy,
  22                                         struct ieee80211_freq_range *freq_limits,
  23                                         unsigned int n_freq_limits,
  24                                         struct ieee80211_channel *chan)
  25{
  26        u32 bw = MHZ_TO_KHZ(20);
  27        int i;
  28
  29        for (i = 0; i < n_freq_limits; i++) {
  30                struct ieee80211_freq_range *limit = &freq_limits[i];
  31
  32                if (cfg80211_does_bw_fit_range(limit,
  33                                               MHZ_TO_KHZ(chan->center_freq),
  34                                               bw))
  35                        return true;
  36        }
  37
  38        return false;
  39}
  40
  41static void wiphy_freq_limits_apply(struct wiphy *wiphy,
  42                                    struct ieee80211_freq_range *freq_limits,
  43                                    unsigned int n_freq_limits)
  44{
  45        enum nl80211_band band;
  46        int i;
  47
  48        if (WARN_ON(!n_freq_limits))
  49                return;
  50
  51        for (band = 0; band < NUM_NL80211_BANDS; band++) {
  52                struct ieee80211_supported_band *sband = wiphy->bands[band];
  53
  54                if (!sband)
  55                        continue;
  56
  57                for (i = 0; i < sband->n_channels; i++) {
  58                        struct ieee80211_channel *chan = &sband->channels[i];
  59
  60                        if (chan->flags & IEEE80211_CHAN_DISABLED)
  61                                continue;
  62
  63                        if (!wiphy_freq_limits_valid_chan(wiphy, freq_limits,
  64                                                          n_freq_limits,
  65                                                          chan)) {
  66                                pr_debug("Disabling freq %d MHz as it's out of OF limits\n",
  67                                         chan->center_freq);
  68                                chan->flags |= IEEE80211_CHAN_DISABLED;
  69                        }
  70                }
  71        }
  72}
  73
  74void wiphy_read_of_freq_limits(struct wiphy *wiphy)
  75{
  76        struct device *dev = wiphy_dev(wiphy);
  77        struct device_node *np;
  78        struct property *prop;
  79        struct ieee80211_freq_range *freq_limits;
  80        unsigned int n_freq_limits;
  81        const __be32 *p;
  82        int len, i;
  83        int err = 0;
  84
  85        if (!dev)
  86                return;
  87        np = dev_of_node(dev);
  88        if (!np)
  89                return;
  90
  91        prop = of_find_property(np, "ieee80211-freq-limit", &len);
  92        if (!prop)
  93                return;
  94
  95        if (!len || len % sizeof(u32) || len / sizeof(u32) % 2) {
  96                dev_err(dev, "ieee80211-freq-limit wrong format");
  97                return;
  98        }
  99        n_freq_limits = len / sizeof(u32) / 2;
 100
 101        freq_limits = kcalloc(n_freq_limits, sizeof(*freq_limits), GFP_KERNEL);
 102        if (!freq_limits) {
 103                err = -ENOMEM;
 104                goto out_kfree;
 105        }
 106
 107        p = NULL;
 108        for (i = 0; i < n_freq_limits; i++) {
 109                struct ieee80211_freq_range *limit = &freq_limits[i];
 110
 111                p = of_prop_next_u32(prop, p, &limit->start_freq_khz);
 112                if (!p) {
 113                        err = -EINVAL;
 114                        goto out_kfree;
 115                }
 116
 117                p = of_prop_next_u32(prop, p, &limit->end_freq_khz);
 118                if (!p) {
 119                        err = -EINVAL;
 120                        goto out_kfree;
 121                }
 122
 123                if (!limit->start_freq_khz ||
 124                    !limit->end_freq_khz ||
 125                    limit->start_freq_khz >= limit->end_freq_khz) {
 126                        err = -EINVAL;
 127                        goto out_kfree;
 128                }
 129        }
 130
 131        wiphy_freq_limits_apply(wiphy, freq_limits, n_freq_limits);
 132
 133out_kfree:
 134        kfree(freq_limits);
 135        if (err)
 136                dev_err(dev, "Failed to get limits: %d\n", err);
 137}
 138EXPORT_SYMBOL(wiphy_read_of_freq_limits);
 139