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 21 static 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 41 static 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 74 void 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); 132 133 out_kfree: 134 kfree(freq_limits); 135 if (err) 136 dev_err(dev, "Failed to get limits: %d\n", err); 137 } 138 EXPORT_SYMBOL(wiphy_read_of_freq_limits); 139