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(freq_range: limit, |
33 | MHZ_TO_KHZ(chan->center_freq), |
34 | bw_khz: 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, name: "ieee80211-freq-limit" , lenp: &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: n_freq_limits, size: 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, cur: p, pu: &limit->start_freq_khz); |
112 | if (!p) { |
113 | err = -EINVAL; |
114 | goto out_kfree; |
115 | } |
116 | |
117 | p = of_prop_next_u32(prop, cur: p, pu: &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(objp: 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 | |