mac80211: backport cfg80211 support for ieee80211-freq-limit DT property

This property allows specifying extra limits for wireless device in DT.
For a full documentation see upstream commit b330b25eaabd ("dt-bindings:
document common IEEE 802.11 frequency limit property").

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
This commit is contained in:
Rafał Miłecki 2017-01-06 15:01:48 +01:00
parent 4235cd0d95
commit 188626f17c
2 changed files with 312 additions and 0 deletions

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@ -0,0 +1,101 @@
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Wed, 4 Jan 2017 18:58:30 +0100
Subject: [PATCH] cfg80211: move function checking range fit to util.c
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
It is needed for another cfg80211 helper that will be out of reg.c so
move it to common util.c file and make it non-static.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
--- a/net/wireless/core.h
+++ b/net/wireless/core.h
@@ -429,6 +429,9 @@ int cfg80211_change_iface(struct cfg8021
void cfg80211_process_rdev_events(struct cfg80211_registered_device *rdev);
void cfg80211_process_wdev_events(struct wireless_dev *wdev);
+bool cfg80211_does_bw_fit_range(const struct ieee80211_freq_range *freq_range,
+ u32 center_freq_khz, u32 bw_khz);
+
/**
* cfg80211_chandef_dfs_usable - checks if chandef is DFS usable
* @wiphy: the wiphy to validate against
--- a/net/wireless/reg.c
+++ b/net/wireless/reg.c
@@ -748,21 +748,6 @@ static bool is_valid_rd(const struct iee
return true;
}
-static bool reg_does_bw_fit(const struct ieee80211_freq_range *freq_range,
- u32 center_freq_khz, u32 bw_khz)
-{
- u32 start_freq_khz, end_freq_khz;
-
- start_freq_khz = center_freq_khz - (bw_khz/2);
- end_freq_khz = center_freq_khz + (bw_khz/2);
-
- if (start_freq_khz >= freq_range->start_freq_khz &&
- end_freq_khz <= freq_range->end_freq_khz)
- return true;
-
- return false;
-}
-
/**
* freq_in_rule_band - tells us if a frequency is in a frequency band
* @freq_range: frequency rule we want to query
@@ -1070,7 +1055,7 @@ freq_reg_info_regd(u32 center_freq,
if (!band_rule_found)
band_rule_found = freq_in_rule_band(fr, center_freq);
- bw_fits = reg_does_bw_fit(fr, center_freq, bw);
+ bw_fits = cfg80211_does_bw_fit_range(fr, center_freq, bw);
if (band_rule_found && bw_fits)
return rr;
@@ -1138,11 +1123,13 @@ static uint32_t reg_rule_to_chan_bw_flag
max_bandwidth_khz = reg_get_max_bandwidth(regd, reg_rule);
/* If we get a reg_rule we can assume that at least 5Mhz fit */
- if (!reg_does_bw_fit(freq_range, MHZ_TO_KHZ(chan->center_freq),
- MHZ_TO_KHZ(10)))
+ if (!cfg80211_does_bw_fit_range(freq_range,
+ MHZ_TO_KHZ(chan->center_freq),
+ MHZ_TO_KHZ(10)))
bw_flags |= IEEE80211_CHAN_NO_10MHZ;
- if (!reg_does_bw_fit(freq_range, MHZ_TO_KHZ(chan->center_freq),
- MHZ_TO_KHZ(20)))
+ if (!cfg80211_does_bw_fit_range(freq_range,
+ MHZ_TO_KHZ(chan->center_freq),
+ MHZ_TO_KHZ(20)))
bw_flags |= IEEE80211_CHAN_NO_20MHZ;
if (max_bandwidth_khz < MHZ_TO_KHZ(10))
--- a/net/wireless/util.c
+++ b/net/wireless/util.c
@@ -1788,6 +1788,21 @@ void cfg80211_free_nan_func(struct cfg80
}
EXPORT_SYMBOL(cfg80211_free_nan_func);
+bool cfg80211_does_bw_fit_range(const struct ieee80211_freq_range *freq_range,
+ u32 center_freq_khz, u32 bw_khz)
+{
+ u32 start_freq_khz, end_freq_khz;
+
+ start_freq_khz = center_freq_khz - (bw_khz / 2);
+ end_freq_khz = center_freq_khz + (bw_khz / 2);
+
+ if (start_freq_khz >= freq_range->start_freq_khz &&
+ end_freq_khz <= freq_range->end_freq_khz)
+ return true;
+
+ return false;
+}
+
/* See IEEE 802.1H for LLC/SNAP encapsulation/decapsulation */
/* Ethernet-II snap header (RFC1042 for most EtherTypes) */
const unsigned char rfc1042_header[] __aligned(2) =

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@ -0,0 +1,211 @@
From: =?UTF-8?q?Rafa=C5=82=20Mi=C5=82ecki?= <rafal@milecki.pl>
Date: Wed, 4 Jan 2017 18:58:31 +0100
Subject: [PATCH] cfg80211: support ieee80211-freq-limit DT property
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
This patch adds a helper for reading that new property and applying
limitations of supported channels specified this way.
It is used with devices that normally support a wide wireless band but
in a given config are limited to some part of it (usually due to board
design). For example a dual-band chipset may be able to support one band
only because of used antennas.
It's also common that tri-band routers have separated radios for lower
and higher part of 5 GHz band and it may be impossible to say which is
which without a DT info.
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
[add new function to documentation, fix link]
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
---
create mode 100644 net/wireless/of.c
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -311,6 +311,34 @@ struct ieee80211_supported_band {
struct ieee80211_sta_vht_cap vht_cap;
};
+/**
+ * wiphy_read_of_freq_limits - read frequency limits from device tree
+ *
+ * @wiphy: the wireless device to get extra limits for
+ *
+ * Some devices may have extra limitations specified in DT. This may be useful
+ * for chipsets that normally support more bands but are limited due to board
+ * design (e.g. by antennas or external power amplifier).
+ *
+ * This function reads info from DT and uses it to *modify* channels (disable
+ * unavailable ones). It's usually a *bad* idea to use it in drivers with
+ * shared channel data as DT limitations are device specific. You should make
+ * sure to call it only if channels in wiphy are copied and can be modified
+ * without affecting other devices.
+ *
+ * As this function access device node it has to be called after set_wiphy_dev.
+ * It also modifies channels so they have to be set first.
+ * If using this helper, call it before wiphy_register().
+ */
+#ifdef CONFIG_OF
+void wiphy_read_of_freq_limits(struct wiphy *wiphy);
+#else /* CONFIG_OF */
+static inline void wiphy_read_of_freq_limits(struct wiphy *wiphy)
+{
+}
+#endif /* !CONFIG_OF */
+
+
/*
* Wireless hardware/device configuration structures and methods
*/
--- a/net/wireless/Makefile
+++ b/net/wireless/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_WEXT_PRIV) += wext-priv.o
cfg80211-y += core.o sysfs.o radiotap.o util.o reg.o scan.o nl80211.o
cfg80211-y += mlme.o ibss.o sme.o chan.o ethtool.o mesh.o ap.o trace.o ocb.o
+cfg80211-$(CONFIG_OF) += of.o
cfg80211-$(CPTCFG_CFG80211_DEBUGFS) += debugfs.o
cfg80211-$(CPTCFG_CFG80211_WEXT) += wext-compat.o wext-sme.o
cfg80211-$(CPTCFG_CFG80211_INTERNAL_REGDB) += regdb.o
--- /dev/null
+++ b/net/wireless/of.c
@@ -0,0 +1,138 @@
+/*
+ * Copyright (C) 2017 Rafał Miłecki <rafal@milecki.pl>
+ *
+ * Permission to use, copy, modify, and/or distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <linux/of.h>
+#include <net/cfg80211.h>
+#include "core.h"
+
+static bool wiphy_freq_limits_valid_chan(struct wiphy *wiphy,
+ struct ieee80211_freq_range *freq_limits,
+ unsigned int n_freq_limits,
+ struct ieee80211_channel *chan)
+{
+ u32 bw = MHZ_TO_KHZ(20);
+ int i;
+
+ for (i = 0; i < n_freq_limits; i++) {
+ struct ieee80211_freq_range *limit = &freq_limits[i];
+
+ if (cfg80211_does_bw_fit_range(limit,
+ MHZ_TO_KHZ(chan->center_freq),
+ bw))
+ return true;
+ }
+
+ return false;
+}
+
+static void wiphy_freq_limits_apply(struct wiphy *wiphy,
+ struct ieee80211_freq_range *freq_limits,
+ unsigned int n_freq_limits)
+{
+ enum nl80211_band band;
+ int i;
+
+ if (WARN_ON(!n_freq_limits))
+ return;
+
+ for (band = 0; band < NUM_NL80211_BANDS; band++) {
+ struct ieee80211_supported_band *sband = wiphy->bands[band];
+
+ if (!sband)
+ continue;
+
+ for (i = 0; i < sband->n_channels; i++) {
+ struct ieee80211_channel *chan = &sband->channels[i];
+
+ if (chan->flags & IEEE80211_CHAN_DISABLED)
+ continue;
+
+ if (!wiphy_freq_limits_valid_chan(wiphy, freq_limits,
+ n_freq_limits,
+ chan)) {
+ pr_debug("Disabling freq %d MHz as it's out of OF limits\n",
+ chan->center_freq);
+ chan->flags |= IEEE80211_CHAN_DISABLED;
+ }
+ }
+ }
+}
+
+void wiphy_read_of_freq_limits(struct wiphy *wiphy)
+{
+ struct device *dev = wiphy_dev(wiphy);
+ struct device_node *np;
+ struct property *prop;
+ struct ieee80211_freq_range *freq_limits;
+ unsigned int n_freq_limits;
+ const __be32 *p;
+ int len, i;
+ int err = 0;
+
+ if (!dev)
+ return;
+ np = dev_of_node(dev);
+ if (!np)
+ return;
+
+ prop = of_find_property(np, "ieee80211-freq-limit", &len);
+ if (!prop)
+ return;
+
+ if (!len || len % sizeof(u32) || len / sizeof(u32) % 2) {
+ dev_err(dev, "ieee80211-freq-limit wrong format");
+ return;
+ }
+ n_freq_limits = len / sizeof(u32) / 2;
+
+ freq_limits = kcalloc(n_freq_limits, sizeof(*freq_limits), GFP_KERNEL);
+ if (!freq_limits) {
+ err = -ENOMEM;
+ goto out_kfree;
+ }
+
+ p = NULL;
+ for (i = 0; i < n_freq_limits; i++) {
+ struct ieee80211_freq_range *limit = &freq_limits[i];
+
+ p = of_prop_next_u32(prop, p, &limit->start_freq_khz);
+ if (!p) {
+ err = -EINVAL;
+ goto out_kfree;
+ }
+
+ p = of_prop_next_u32(prop, p, &limit->end_freq_khz);
+ if (!p) {
+ err = -EINVAL;
+ goto out_kfree;
+ }
+
+ if (!limit->start_freq_khz ||
+ !limit->end_freq_khz ||
+ limit->start_freq_khz >= limit->end_freq_khz) {
+ err = -EINVAL;
+ goto out_kfree;
+ }
+ }
+
+ wiphy_freq_limits_apply(wiphy, freq_limits, n_freq_limits);
+
+out_kfree:
+ kfree(freq_limits);
+ if (err)
+ dev_err(dev, "Failed to get limits: %d\n", err);
+}
+EXPORT_SYMBOL(wiphy_read_of_freq_limits);