188626f17c
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>
211 lines
6.3 KiB
Diff
211 lines
6.3 KiB
Diff
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);
|