cfg80211: support ieee80211-freq-limit DT property (e691ac2f) · Commits · e / devices / android_kernel_teracube_mt6765

Documentation/80211/cfg80211.rst

+3 −0

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		@@ -44,6 +44,9 @@ Device registration
		.. kernel-doc:: include/net/cfg80211.h
		:functions: wiphy_new

		.. kernel-doc:: include/net/cfg80211.h
		:functions: wiphy_read_of_freq_limits

		.. kernel-doc:: include/net/cfg80211.h
		:functions: wiphy_register

include/net/cfg80211.h

+28 −0

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		@@ -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
		*/

net/wireless/Makefile

+1 −0

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		@@ -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-$(CONFIG_OF) += of.o
		cfg80211-$(CONFIG_CFG80211_DEBUGFS) += debugfs.o
		cfg80211-$(CONFIG_CFG80211_WEXT) += wext-compat.o wext-sme.o
		cfg80211-$(CONFIG_CFG80211_INTERNAL_REGDB) += regdb.o

net/wireless/of.c

0 → 100644

+138 −0

Original line number	Diff line number	Diff line
		/*
		* 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);