[RFC 0/2] control Bluetooth coexistence

[RFC 0/2] control Bluetooth coexistence

[Piotr Haber]

As 802.11 and Bluetooth devices can interfere with each other
several coexistence techniques exist. 
This is particularly important for devices that share antenna
and analog front end between Wifi and Bluetooth.
There are situations when software control over the coexistence
algorithm behavior would be beneficial - ex. giving EAPOL handshake
or DHCP negotiation high priority.

This two patches add possibility to control Wifi-Bluetooth coexistence mode.
First one extends wiphy params with coexistence mode setting.
Second one implements coexistence control for brcmfmac.

[RFC] cfg80211: configuration of Bluetooth coexistence mode
brcmfmac: control BT coexistence parameters

-- 
1.7.9.5

[PATCH 1/2] [RFC] cfg80211: configuration of Bluetooth coexistence mode

[Piotr Haber]

Some devices share antenna/analog front end between Wifi
and Bluetooth. The hardware coexistence interface allows
them to do so, but there are situations when it would
be beneficial if software had a way to have influence on it
as well. It can be used to protect time sensitive
traffic in presence of Bluetooth voice stream,
for an example EAPOL handshake or DHCP negotiation.

This patch adds new attribute to SET_WIPHY command
and a new field in struct wiphy to allow control of the
coexistence behavior. Devices that do not share resources
with Bluetooth can ignore this parameter.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Piotr Haber <phaber@broadcom.com>
---
 include/net/cfg80211.h       |    4 ++++
 include/uapi/linux/nl80211.h |   20 ++++++++++++++++++++
 net/wireless/nl80211.c       |   22 +++++++++++++++++++++-
 3 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/include/net/cfg80211.h b/include/net/cfg80211.h
index 36e076e..3db21be 100644
--- a/include/net/cfg80211.h
+++ b/include/net/cfg80211.h
@@ -1526,6 +1526,7 @@ struct cfg80211_connect_params {
  * @WIPHY_PARAM_FRAG_THRESHOLD: wiphy->frag_threshold has changed
  * @WIPHY_PARAM_RTS_THRESHOLD: wiphy->rts_threshold has changed
  * @WIPHY_PARAM_COVERAGE_CLASS: coverage class changed
+ * @WIPHY_PARAM_BTCOEX: Bluetooth coexistence mode changed
  */
 enum wiphy_params_flags {
 	WIPHY_PARAM_RETRY_SHORT		= 1 << 0,
@@ -1533,6 +1534,7 @@ enum wiphy_params_flags {
 	WIPHY_PARAM_FRAG_THRESHOLD	= 1 << 2,
 	WIPHY_PARAM_RTS_THRESHOLD	= 1 << 3,
 	WIPHY_PARAM_COVERAGE_CLASS	= 1 << 4,
+	WIPHY_PARAM_BTCOEX_MODE		= 1 << 5,
 };
 
 /*
@@ -2322,6 +2324,7 @@ struct wiphy_wowlan_support {
  * @max_sched_scan_ie_len: same as max_scan_ie_len, but for scheduled
  *	scans
  * @coverage_class: current coverage class
+ * @btcoex_mode: Wifi-Bluetooth coexistence mode
  * @fw_version: firmware version for ethtool reporting
  * @hw_version: hardware version for ethtool reporting
  * @max_num_pmkids: maximum number of PMKIDs supported by device
@@ -2401,6 +2404,7 @@ struct wiphy {
 	u32 frag_threshold;
 	u32 rts_threshold;
 	u8 coverage_class;
+	enum nl80211_btcoex_mode btcoex_mode;
 
 	char fw_version[ETHTOOL_BUSINFO_LEN];
 	u32 hw_version;
diff --git a/include/uapi/linux/nl80211.h b/include/uapi/linux/nl80211.h
index 5b7dbc1..a96e1c9 100644
--- a/include/uapi/linux/nl80211.h
+++ b/include/uapi/linux/nl80211.h
@@ -1336,6 +1336,9 @@ enum nl80211_commands {
  *	number of MAC addresses that a device can support for MAC
  *	ACL.
  *
+ * @NL80211_ATTR_WIPHY_BTCOEX_MODE: u8 attribute to control
+ *	Wifi - Bluetooth coexistence mode
+ *
  * @NL80211_ATTR_MAX: highest attribute number currently defined
  * @__NL80211_ATTR_AFTER_LAST: internal use
  */
@@ -1614,6 +1617,8 @@ enum nl80211_attrs {
 
 	NL80211_ATTR_MAC_ACL_MAX,
 
+	NL80211_ATTR_WIPHY_BTCOEX_MODE,
+
 	/* add attributes here, update the policy in nl80211.c */
 
 	__NL80211_ATTR_AFTER_LAST,
@@ -3323,4 +3328,19 @@ enum nl80211_acl_policy {
 	NL80211_ACL_POLICY_DENY_UNLESS_LISTED,
 };
 
+/**
+ * enum nl80211_btcoex_mode - Bluetooth coexistence mode
+ *
+ * Control Wifi - Bluetooth coexistence mode,
+ * to be used with %NL80211_ATTR_WIPHY_BTCOEX_MODE.
+ *
+ * @NL80211_BTCOEX_ENABLED: enable coexistence
+ * @NL80211_BTCOEX_DISABLED: disable coexistence, give Wifi
+ *	traffic priority over Bluetooth
+ */
+enum nl80211_btcoex_mode {
+	NL80211_BTCOEX_ENABLED,
+	NL80211_BTCOEX_DISABLED,
+};
+
 #endif /* __LINUX_NL80211_H */
diff --git a/net/wireless/nl80211.c b/net/wireless/nl80211.c
index b5978ab..f8f99ef 100644
--- a/net/wireless/nl80211.c
+++ b/net/wireless/nl80211.c
@@ -367,6 +367,7 @@ static const struct nla_policy nl80211_policy[NL80211_ATTR_MAX+1] = {
 	[NL80211_ATTR_P2P_OPPPS] = { .type = NLA_U8 },
 	[NL80211_ATTR_ACL_POLICY] = {. type = NLA_U32 },
 	[NL80211_ATTR_MAC_ADDRS] = { .type = NLA_NESTED },
+	[NL80211_ATTR_WIPHY_BTCOEX_MODE] = { .type = NLA_U8},
 };
 
 /* policy for the key attributes */
@@ -914,7 +915,9 @@ static int nl80211_send_wiphy(struct sk_buff *msg, u32 portid, u32 seq, int flag
 	    nla_put_u16(msg, NL80211_ATTR_MAX_SCHED_SCAN_IE_LEN,
 			dev->wiphy.max_sched_scan_ie_len) ||
 	    nla_put_u8(msg, NL80211_ATTR_MAX_MATCH_SETS,
-		       dev->wiphy.max_match_sets))
+		       dev->wiphy.max_match_sets) ||
+	    nla_put_u8(msg, NL80211_ATTR_WIPHY_BTCOEX_MODE,
+		       dev->wiphy.btcoex_mode))
 		goto nla_put_failure;
 
 	if ((dev->wiphy.flags & WIPHY_FLAG_IBSS_RSN) &&
@@ -1528,6 +1531,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 	u8 retry_short = 0, retry_long = 0;
 	u32 frag_threshold = 0, rts_threshold = 0;
 	u8 coverage_class = 0;
+	enum nl80211_btcoex_mode btcoex_mode = NL80211_BTCOEX_ENABLED;
 
 	/*
 	 * Try to find the wiphy and netdev. Normally this
@@ -1745,10 +1749,22 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 		changed |= WIPHY_PARAM_COVERAGE_CLASS;
 	}
 
+	if (info->attrs[NL80211_ATTR_WIPHY_BTCOEX_MODE]) {
+		btcoex_mode = nla_get_u8(
+			info->attrs[NL80211_ATTR_WIPHY_BTCOEX_MODE]);
+		if (btcoex_mode != NL80211_BTCOEX_ENABLED &&
+		    btcoex_mode != NL80211_BTCOEX_DISABLED) {
+			result = -EINVAL;
+			goto bad_res;
+		}
+		changed |= WIPHY_PARAM_BTCOEX_MODE;
+	}
+
 	if (changed) {
 		u8 old_retry_short, old_retry_long;
 		u32 old_frag_threshold, old_rts_threshold;
 		u8 old_coverage_class;
+		enum nl80211_btcoex_mode old_btcoex_mode;
 
 		if (!rdev->ops->set_wiphy_params) {
 			result = -EOPNOTSUPP;
@@ -1760,6 +1776,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 		old_frag_threshold = rdev->wiphy.frag_threshold;
 		old_rts_threshold = rdev->wiphy.rts_threshold;
 		old_coverage_class = rdev->wiphy.coverage_class;
+		old_btcoex_mode = rdev->wiphy.btcoex_mode;
 
 		if (changed & WIPHY_PARAM_RETRY_SHORT)
 			rdev->wiphy.retry_short = retry_short;
@@ -1771,6 +1788,8 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 			rdev->wiphy.rts_threshold = rts_threshold;
 		if (changed & WIPHY_PARAM_COVERAGE_CLASS)
 			rdev->wiphy.coverage_class = coverage_class;
+		if (changed & WIPHY_PARAM_BTCOEX_MODE)
+			rdev->wiphy.btcoex_mode = btcoex_mode;
 
 		result = rdev_set_wiphy_params(rdev, changed);
 		if (result) {
@@ -1779,6 +1798,7 @@ static int nl80211_set_wiphy(struct sk_buff *skb, struct genl_info *info)
 			rdev->wiphy.frag_threshold = old_frag_threshold;
 			rdev->wiphy.rts_threshold = old_rts_threshold;
 			rdev->wiphy.coverage_class = old_coverage_class;
+			rdev->wiphy.btcoex_mode = old_btcoex_mode;
 		}
 	}
 
-- 
1.7.9.5

[PATCH 2/2] brcmfmac: control BT coexistence parameters

[Piotr Haber]

Introduce feature to give Wifi traffic priority over Bluetooth.

Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Piotr Haber <phaber@broadcom.com>
---
 drivers/net/wireless/brcm80211/brcmfmac/Makefile   |    3 +-
 drivers/net/wireless/brcm80211/brcmfmac/btcoex.c   |  472 ++++++++++++++++++++
 drivers/net/wireless/brcm80211/brcmfmac/btcoex.h   |   24 +
 .../net/wireless/brcm80211/brcmfmac/wl_cfg80211.c  |   11 +
 .../net/wireless/brcm80211/brcmfmac/wl_cfg80211.h  |    3 +
 5 files changed, 512 insertions(+), 1 deletion(-)
 create mode 100644 drivers/net/wireless/brcm80211/brcmfmac/btcoex.c
 create mode 100644 drivers/net/wireless/brcm80211/brcmfmac/btcoex.h

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/Makefile b/drivers/net/wireless/brcm80211/brcmfmac/Makefile
index 4d58aee..6421926 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/Makefile
+++ b/drivers/net/wireless/brcm80211/brcmfmac/Makefile
@@ -30,7 +30,8 @@ brcmfmac-objs += \
 		p2p.o \
 		dhd_cdc.o \
 		dhd_common.o \
-		dhd_linux.o
+		dhd_linux.o \
+		btcoex.o
 brcmfmac-$(CONFIG_BRCMFMAC_SDIO) += \
 		dhd_sdio.o \
 		bcmsdh.o \
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/btcoex.c b/drivers/net/wireless/brcm80211/brcmfmac/btcoex.c
new file mode 100644
index 0000000..09f5721
--- /dev/null
+++ b/drivers/net/wireless/brcm80211/brcmfmac/btcoex.c
@@ -0,0 +1,472 @@
+/*
+ * Copyright (c) 2013 Broadcom Corporation
+ *
+ * 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/slab.h>
+#include <linux/netdevice.h>
+#include <net/cfg80211.h>
+
+#include <brcmu_wifi.h>
+#include <brcmu_utils.h>
+#include <defs.h>
+#include <dhd.h>
+#include <dhd_dbg.h>
+#include "fwil.h"
+#include "fwil_types.h"
+#include "btcoex.h"
+#include "p2p.h"
+#include "wl_cfg80211.h"
+
+/* T1 start SCO/eSCO priority suppression */
+#define BRCMF_BT_DHCP_OPPR_WIN_TIME   2500
+/* T2 turn off SCO/eSCO suppresion */
+#define BRCMF_BT_DHCP_FLAG_FORCE_TIME 5500
+
+/* BT registers values during DHCP */
+#define BRCMF_BT_DHCP_REG50 0x8022
+#define BRCMF_BT_DHCP_REG51 0
+#define BRCMF_BT_DHCP_REG64 0
+#define BRCMF_BT_DHCP_REG65 0
+#define BRCMF_BT_DHCP_REG71 0
+#define BRCMF_BT_DHCP_REG66 0x2710
+#define BRCMF_BT_DHCP_REG41 0x33
+#define BRCMF_BT_DHCP_REG68 0x190
+
+/* number of samples for SCO detection */
+#define BRCMF_BT_SCO_SAMPLES 12
+
+/**
+* enum brcmf_btcoex_state - BT coex DHCP state machine states
+* @BRCMF_BT_DHCP_IDLE: DCHP is idle
+* @BRCMF_BT_DHCP_START: DHCP started, wait before
+*			boosting wifi priority
+* @BRCMF_BT_DHCP_OPPR_WIN: graceful DHCP opportunity ended,
+*			boost wifi priority
+* @BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT: wifi priority boost end,
+*			restore defaults
+*/
+enum brcmf_btcoex_state {
+	BRCMF_BT_DHCP_IDLE,
+	BRCMF_BT_DHCP_START,
+	BRCMF_BT_DHCP_OPPR_WIN,
+	BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT
+};
+
+/**
+* struct brcmf_btcoex_info - BT coex related information
+* @timer: timer for DHCP state machine
+* @timer_on:  DHCP timer active
+* @dhcp_done: DHCP finished before T1/T2 timer expiration
+* @bt_state: DHCP state machine state
+* @work: DHCP state machine work
+* @cfg: driver private data for cfg80211 interface
+* @saved_reg66: saved value of btc_params 66
+* @saved_reg41: saved value of btc_params 41
+* @saved_reg68: saved value of btc_params 68
+* @saved_regs_part1: flag indicating regs 66,41,68
+*			have been saved
+* @saved_reg51: saved value of btc_params 51
+* @saved_reg64: saved value of btc_params 64
+* @saved_reg65: saved value of btc_params 65
+* @saved_reg71: saved value of btc_params 71
+* @saved_regs_part1: flag indicating regs 50,51,64,65,71
+*			have been saved
+*/
+struct brcmf_btcoex_info {
+	struct timer_list timer;
+	bool timer_on;
+	bool dhcp_done;
+	enum brcmf_btcoex_state bt_state;
+	struct work_struct work;
+	struct brcmf_cfg80211_info *cfg;
+	u32 saved_reg66;
+	u32 saved_reg41;
+	u32 saved_reg68;
+	bool saved_regs_part1;
+	u32 saved_reg50;
+	u32 saved_reg51;
+	u32 saved_reg64;
+	u32 saved_reg65;
+	u32 saved_reg71;
+	bool saved_regs_part2;
+};
+
+/**
+ * brcmf_btcoex_btcparams_write() - write bts_params firmware variable
+ * @ifp: interface
+ * @addr: btc_params register number
+ * @data: data to write
+ */
+static s32 brcmf_btcoex_btcparams_write(struct brcmf_if *ifp,
+				  u32 addr, u32 data)
+{
+	struct {
+		__le32 addr;
+		__le32 data;
+	} reg_write;
+
+	reg_write.addr = cpu_to_le32(addr);
+	reg_write.data = cpu_to_le32(data);
+	return brcmf_fil_iovar_data_set(ifp, "btc_params",
+					&reg_write, sizeof(reg_write));
+}
+
+/**
+ * brcmf_btcoex_btcparams_read() - read bts_params firmware variable
+ * @ifp: interface
+ * @addr: btc_params register number
+ * @data: read data
+ */
+static s32 brcmf_btcoex_btcparams_read(struct brcmf_if *ifp,
+				 u32 addr, u32 *data)
+{
+	*data = addr;
+
+	return brcmf_fil_iovar_int_get(ifp, "btc_params", data);
+}
+
+/**
+ * brcmf_btcoex_boost_wifi() - control BT SCO/eSCO parameters
+ * @btcx_inf: BT coex info
+ * @trump_sco:
+ *	true - set SCO/eSCO parameters for compatibility
+ *		during DHCP window
+ *	false - restore saved parameter values
+ *
+ * Enhanced BT COEX settings for eSCO compatibility during DHCP window
+ */
+static void brcmf_btcoex_boost_wifi(struct brcmf_btcoex_info *btcx_inf,
+				    bool trump_sco)
+{
+	struct brcmf_if *ifp = btcx_inf->cfg->pub->iflist[0];
+
+	if (trump_sco && !btcx_inf->saved_regs_part2) {
+		/* this should reduce eSCO agressive
+		 * retransmit w/o breaking it
+		 */
+
+		/* save current */
+		brcmf_dbg(TRACE, "new SCO/eSCO coex algo {save & override}\n");
+		brcmf_btcoex_btcparams_read(ifp, 50,
+					    &btcx_inf->saved_reg50);
+		brcmf_btcoex_btcparams_read(ifp, 51,
+					    &btcx_inf->saved_reg51);
+		brcmf_btcoex_btcparams_read(ifp, 64,
+					    &btcx_inf->saved_reg64);
+		brcmf_btcoex_btcparams_read(ifp, 65,
+					    &btcx_inf->saved_reg65);
+		brcmf_btcoex_btcparams_read(ifp, 71,
+					    &btcx_inf->saved_reg71);
+
+		btcx_inf->saved_regs_part2 = true;
+		brcmf_dbg(TRACE,
+			  "saved bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
+			  btcx_inf->saved_reg50, btcx_inf->saved_reg51,
+			  btcx_inf->saved_reg64, btcx_inf->saved_reg65,
+			  btcx_inf->saved_reg71);
+
+		/* pacify the eSco   */
+		brcmf_btcoex_btcparams_write(ifp, 50,
+					     BRCMF_BT_DHCP_REG50);
+		brcmf_btcoex_btcparams_write(ifp, 51,
+					     BRCMF_BT_DHCP_REG51);
+		brcmf_btcoex_btcparams_write(ifp, 64,
+					     BRCMF_BT_DHCP_REG64);
+		brcmf_btcoex_btcparams_write(ifp, 65,
+					     BRCMF_BT_DHCP_REG65);
+		brcmf_btcoex_btcparams_write(ifp, 71,
+					     BRCMF_BT_DHCP_REG71);
+
+	} else if (btcx_inf->saved_regs_part2) {
+		/* restore previously saved bt params */
+		brcmf_dbg(TRACE, "Do new SCO/eSCO coex algo {restore}\n");
+		brcmf_btcoex_btcparams_write(ifp, 50,
+					     btcx_inf->saved_reg50);
+		brcmf_btcoex_btcparams_write(ifp, 51,
+					     btcx_inf->saved_reg51);
+		brcmf_btcoex_btcparams_write(ifp, 64,
+					     btcx_inf->saved_reg64);
+		brcmf_btcoex_btcparams_write(ifp, 65,
+					     btcx_inf->saved_reg65);
+		brcmf_btcoex_btcparams_write(ifp, 71,
+					     btcx_inf->saved_reg71);
+
+		brcmf_dbg(TRACE,
+			  "restored bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
+			  btcx_inf->saved_reg50, btcx_inf->saved_reg51,
+			  btcx_inf->saved_reg64, btcx_inf->saved_reg65,
+			  btcx_inf->saved_reg71);
+
+		btcx_inf->saved_regs_part2 = false;
+	} else {
+		brcmf_err("attempted to restore not saved BTCOEX params\n");
+	}
+}
+
+/**
+ * brcmf_btcoex_is_sco_active() - check if SCO/eSCO is active
+ * @ifp: interface
+ *
+ * return: true if SCO/eSCO session is active
+ */
+static bool brcmf_btcoex_is_sco_active(struct brcmf_if *ifp)
+{
+	int ioc_res = 0;
+	bool res = false;
+	int sco_id_cnt = 0;
+	u32 param27;
+	int i;
+
+	for (i = 0; i < BRCMF_BT_SCO_SAMPLES; i++) {
+		ioc_res = brcmf_btcoex_btcparams_read(ifp, 27,
+						      &param27);
+
+		if (ioc_res < 0) {
+			brcmf_err("ioc read btc params error\n");
+			break;
+		}
+
+		brcmf_dbg(TRACE, "sample[%d], btc_params 27:%x\n", i, param27);
+
+		if ((param27 & 0x6) == 2) { /* count both sco & esco  */
+			sco_id_cnt++;
+		}
+
+		if (sco_id_cnt > 2) {
+			brcmf_dbg(TRACE,
+				  "sco/esco detected, pkt id_cnt:%d samples:%d\n",
+				  sco_id_cnt, i);
+			res = true;
+			break;
+		}
+	}
+	return res;
+}
+
+/**
+ * brcmf_btcoex_timerfunc() - BT coex timer callback
+ */
+static void brcmf_btcoex_timerfunc(ulong data)
+{
+	struct brcmf_btcoex_info *bt_local = (struct brcmf_btcoex_info *)data;
+	brcmf_dbg(TRACE, "enter\n");
+
+	bt_local->timer_on = false;
+	schedule_work(&bt_local->work);
+}
+
+/**
+ * brcmf_btcoex_handler() - BT coex state machine work handler
+ * @work: work
+ */
+static void brcmf_btcoex_handler(struct work_struct *work)
+{
+	struct brcmf_btcoex_info *btcx_inf;
+	btcx_inf = container_of(work, struct brcmf_btcoex_info, work);
+	if (btcx_inf->timer_on) {
+		btcx_inf->timer_on = false;
+		del_timer_sync(&btcx_inf->timer);
+	}
+
+	switch (btcx_inf->bt_state) {
+	case BRCMF_BT_DHCP_START:
+		/* DHCP started provide OPPORTUNITY window
+		   to get DHCP address
+		*/
+		brcmf_dbg(TRACE, "DHCP started\n");
+		btcx_inf->bt_state = BRCMF_BT_DHCP_OPPR_WIN;
+		mod_timer(&btcx_inf->timer, jiffies +
+			  msecs_to_jiffies(BRCMF_BT_DHCP_OPPR_WIN_TIME));
+		btcx_inf->timer_on = true;
+		break;
+
+	case BRCMF_BT_DHCP_OPPR_WIN:
+		if (btcx_inf->dhcp_done) {
+			brcmf_dbg(TRACE, "DHCP done before T1 expiration\n");
+			goto btc_coex_idle;
+		}
+
+		/* DHCP is not over yet, start lowering BT priority */
+		brcmf_dbg(TRACE, "DHCP T1:%d expired\n",
+			  BRCMF_BT_DHCP_OPPR_WIN_TIME);
+		brcmf_btcoex_boost_wifi(btcx_inf, true);
+
+		btcx_inf->bt_state = BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT;
+		mod_timer(&btcx_inf->timer, jiffies +
+			  msecs_to_jiffies(BRCMF_BT_DHCP_FLAG_FORCE_TIME));
+		btcx_inf->timer_on = true;
+		break;
+
+	case BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT:
+		if (btcx_inf->dhcp_done)
+			brcmf_dbg(TRACE, "DHCP done before T2 expiration\n");
+		else
+			brcmf_dbg(TRACE, "DHCP T2:%d expired\n",
+				  BRCMF_BT_DHCP_FLAG_FORCE_TIME);
+
+		/* Restoring default bt priority */
+		brcmf_btcoex_boost_wifi(btcx_inf, false);
+btc_coex_idle:
+		btcx_inf->bt_state = BRCMF_BT_DHCP_IDLE;
+		btcx_inf->timer_on = false;
+		break;
+
+	default:
+		brcmf_dbg(TRACE, "error state=%d !!!\n", btcx_inf->bt_state);
+		brcmf_btcoex_boost_wifi(btcx_inf, false);
+		btcx_inf->bt_state = BRCMF_BT_DHCP_IDLE;
+		btcx_inf->timer_on = false;
+		break;
+	}
+}
+
+/**
+ * brcmf_btcoex_init() - initialize BT coex data
+ * @cfg: driver private cfg80211 data
+ *
+ * return: 0 on success
+ */
+int brcmf_btcoex_init(struct brcmf_cfg80211_info *cfg)
+{
+	struct brcmf_btcoex_info *btco_inf = NULL;
+	brcmf_dbg(TRACE, "enter\n");
+
+	btco_inf = kmalloc(sizeof(struct brcmf_btcoex_info), GFP_KERNEL);
+	if (!btco_inf)
+		return -ENOMEM;
+
+	btco_inf->bt_state = BRCMF_BT_DHCP_IDLE;
+
+	/* Set up timer for BT  */
+	btco_inf->timer_on = false;
+	init_timer(&btco_inf->timer);
+	btco_inf->timer.data = (ulong)btco_inf;
+	btco_inf->timer.function = brcmf_btcoex_timerfunc;
+	btco_inf->cfg = cfg;
+	btco_inf->saved_regs_part1 = false;
+	btco_inf->saved_regs_part2 = false;
+
+	INIT_WORK(&btco_inf->work, brcmf_btcoex_handler);
+
+	cfg->btcoex = btco_inf;
+	return 0;
+}
+
+/**
+ * brcmf_btcoex_deinit - clean BT coex data
+ * @cfg: driver private cfg80211 data
+ */
+void brcmf_btcoex_deinit(struct brcmf_cfg80211_info *cfg)
+{
+	brcmf_dbg(TRACE, "enter\n");
+
+	if (!cfg->btcoex)
+		return;
+
+	if (cfg->btcoex->timer_on) {
+		cfg->btcoex->timer_on = false;
+		del_timer_sync(&cfg->btcoex->timer);
+	}
+
+	cancel_work_sync(&cfg->btcoex->work);
+
+	kfree(cfg->btcoex);
+	cfg->btcoex = NULL;
+}
+
+/**
+ * brcmf_btcoex_set_mode - set BT coex mode
+ * @cfg: driver private cfg80211 data
+ * @mode: Wifi-Bluetooth coexistence mode
+ *
+ * return: 0 on success
+ */
+int brcmf_btcoex_set_mode(struct brcmf_cfg80211_info *cfg,
+			enum nl80211_btcoex_mode mode)
+{
+	struct brcmf_btcoex_info *btco_inf = cfg->btcoex;
+	struct brcmf_if *ifp = cfg->pub->iflist[0];
+
+	switch (mode) {
+	case NL80211_BTCOEX_DISABLED:
+		brcmf_dbg(TRACE, "DHCP session starts\n");
+
+		if (!btco_inf->saved_regs_part1) {
+			/* Retrieve and save original reg value */
+			brcmf_btcoex_btcparams_read(ifp, 66,
+						    &btco_inf->saved_reg66);
+			brcmf_btcoex_btcparams_read(ifp, 41,
+						    &btco_inf->saved_reg41);
+			brcmf_btcoex_btcparams_read(ifp, 68,
+						    &btco_inf->saved_reg68);
+
+			btco_inf->saved_regs_part1 = true;
+			brcmf_dbg(TRACE,
+				  "saved btc_params regs (66,41,68) 0x%x 0x%x 0x%x\n",
+				  btco_inf->saved_reg66, btco_inf->saved_reg41,
+				  btco_inf->saved_reg68);
+		}
+		/* Start BT timer only for SCO connection */
+		if (brcmf_btcoex_is_sco_active(ifp)) {
+			/* set new regs values */
+			brcmf_btcoex_btcparams_write(ifp, 66,
+						     BRCMF_BT_DHCP_REG66);
+			brcmf_btcoex_btcparams_write(ifp, 41,
+						     BRCMF_BT_DHCP_REG41);
+			brcmf_btcoex_btcparams_write(ifp, 68,
+						     BRCMF_BT_DHCP_REG68);
+			btco_inf->dhcp_done = false;
+			btco_inf->bt_state = BRCMF_BT_DHCP_START;
+			btco_inf->timer_on = true;
+			mod_timer(&btco_inf->timer, btco_inf->timer.expires);
+			brcmf_dbg(TRACE, "enable BT DHCP Timer\n");
+		}
+		break;
+
+	case NL80211_BTCOEX_ENABLED:
+		brcmf_dbg(TRACE, "DHCP session ends\n");
+		/* Stop any bt timer because DHCP session is done */
+		btco_inf->dhcp_done = true;
+		if (btco_inf->timer_on) {
+			brcmf_dbg(TRACE, "disable BT DHCP Timer\n");
+			btco_inf->timer_on = false;
+			del_timer_sync(&btco_inf->timer);
+			if (btco_inf->bt_state != BRCMF_BT_DHCP_IDLE) {
+				brcmf_dbg(TRACE, "bt_state:%d\n",
+					  btco_inf->bt_state);
+				/* wake up btcoex thread */
+				schedule_work(&btco_inf->work);
+			}
+		}
+		/* Restore original values */
+		if (btco_inf->saved_regs_part1) {
+			/* btc_params */
+			brcmf_btcoex_btcparams_write(ifp, 66,
+						     btco_inf->saved_reg66);
+			brcmf_btcoex_btcparams_write(ifp, 41,
+						     btco_inf->saved_reg41);
+			brcmf_btcoex_btcparams_write(ifp, 68,
+						     btco_inf->saved_reg68);
+			brcmf_dbg(TRACE,
+				  "restored btc_params regs {66,41,68} 0x%x 0x%x 0x%x\n",
+				  btco_inf->saved_reg66, btco_inf->saved_reg41,
+				  btco_inf->saved_reg68);
+		}
+		btco_inf->saved_regs_part1 = false;
+		break;
+	default:
+		brcmf_dbg(TRACE, "Unknown mode, ignored\n");
+	}
+	return 0;
+}
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/btcoex.h b/drivers/net/wireless/brcm80211/brcmfmac/btcoex.h
new file mode 100644
index 0000000..5867123
--- /dev/null
+++ b/drivers/net/wireless/brcm80211/brcmfmac/btcoex.h
@@ -0,0 +1,24 @@
+/*
+ * Copyright (c) 2013 Broadcom Corporation
+ *
+ * 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.
+ */
+#ifndef WL_BTCOEX_H_
+#define WL_BTCOEX_H_
+
+int brcmf_btcoex_init(struct brcmf_cfg80211_info *cfg);
+void brcmf_btcoex_deinit(struct brcmf_cfg80211_info *cfg);
+int brcmf_btcoex_set_mode(struct brcmf_cfg80211_info *cfg,
+			  enum nl80211_btcoex_mode mode);
+
+#endif /* WL_BTCOEX_H_ */
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
index a4f27f6..188d142 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
@@ -28,6 +28,7 @@
 #include "dhd_dbg.h"
 #include "fwil_types.h"
 #include "p2p.h"
+#include "btcoex.h"
 #include "wl_cfg80211.h"
 #include "fwil.h"
 
@@ -1084,6 +1085,13 @@ static s32 brcmf_cfg80211_set_wiphy_params(struct wiphy *wiphy, u32 changed)
 		if (!err)
 			goto done;
 	}
+	if (changed & WIPHY_PARAM_BTCOEX_MODE &&
+	    (cfg->conf->btcoex_mode != wiphy->btcoex_mode)) {
+		cfg->conf->btcoex_mode = wiphy->btcoex_mode;
+		err = brcmf_btcoex_set_mode(cfg, cfg->conf->btcoex_mode);
+		if (!err)
+			goto done;
+	}
 
 done:
 	brcmf_dbg(TRACE, "Exit\n");
@@ -4657,6 +4665,7 @@ static void brcmf_init_conf(struct brcmf_cfg80211_conf *conf)
 	conf->retry_short = (u32)-1;
 	conf->retry_long = (u32)-1;
 	conf->tx_power = -1;
+	conf->btcoex_mode = NL80211_BTCOEX_ENABLED;
 }
 
 static void brcmf_register_event_handlers(struct brcmf_cfg80211_info *cfg)
@@ -4814,6 +4823,7 @@ struct brcmf_cfg80211_info *brcmf_cfg80211_attach(struct brcmf_pub *drvr,
 		brcmf_err("P2P initilisation failed (%d)\n", err);
 		goto cfg80211_p2p_attach_out;
 	}
+	brcmf_btcoex_init(cfg);
 
 	return cfg;
 
@@ -4832,6 +4842,7 @@ void brcmf_cfg80211_detach(struct brcmf_cfg80211_info *cfg)
 	struct brcmf_cfg80211_vif *tmp;
 
 	wl_deinit_priv(cfg);
+	brcmf_btcoex_deinit(cfg);
 	list_for_each_entry_safe(vif, tmp, &cfg->vif_list, list) {
 		brcmf_free_vif(vif);
 	}
diff --git a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.h b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.h
index 8b5d498..f764925 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.h
+++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.h
@@ -107,6 +107,7 @@ struct brcmf_cfg80211_conf {
 	u32 retry_long;
 	s32 tx_power;
 	struct ieee80211_channel channel;
+	enum nl80211_btcoex_mode btcoex_mode;
 };
 
 /* basic structure of scan request */
@@ -347,6 +348,7 @@ struct brcmf_cfg80211_vif_event {
  * @wiphy: wiphy object for cfg80211 interface.
  * @conf: dongle configuration.
  * @p2p: peer-to-peer specific information.
+ * @btcoex: Bluetooth coexistence information.
  * @scan_request: cfg80211 scan request object.
  * @usr_sync: mainly for dongle up/down synchronization.
  * @bss_list: bss_list holding scanned ap information.
@@ -380,6 +382,7 @@ struct brcmf_cfg80211_info {
 	struct wiphy *wiphy;
 	struct brcmf_cfg80211_conf *conf;
 	struct brcmf_p2p_info p2p;
+	struct brcmf_btcoex_info *btcoex;
 	struct cfg80211_scan_request *scan_request;
 	struct mutex usr_sync;
 	struct brcmf_scan_results *bss_list;
-- 
1.7.9.5

Re: [PATCH 1/2] [RFC] cfg80211: configuration of Bluetooth coexistence mode

[Johannes Berg]

On Fri, 2013-02-22 at 10:08 +0100, Piotr Haber wrote:
> Some devices share antenna/analog front end between Wifi
> and Bluetooth. The hardware coexistence interface allows
> them to do so, but there are situations when it would
> be beneficial if software had a way to have influence on it
> as well. It can be used to protect time sensitive
> traffic in presence of Bluetooth voice stream,
> for an example EAPOL handshake or DHCP negotiation.
> 
> This patch adds new attribute to SET_WIPHY command
> and a new field in struct wiphy to allow control of the
> coexistence behavior. Devices that do not share resources
> with Bluetooth can ignore this parameter.

Apart from a few minor technical comments that I'll omit for now, I'm
not sure what value this really has? EAPOL can already be "protected" by
way of knowing when the station is marked authorized, and DHCP is pretty
tricky because it could take "forever", might not be there at all, etc.

What application would actually call this? I don't really see how it
could be integrated like that.

johannes

RE: [PATCH 1/2] [RFC] cfg80211: configuration of Bluetooth coexistence mode

[Piotr Haber]

>> From: Johannes Berg [johannes@sipsolutions.net]
>> Sent: Friday, February 22, 2013 12:52 PM
>> To: Piotr Haber
>> Cc: linux-wireless@vger.kernel.org
>> Subject: Re: [PATCH 1/2] [RFC] cfg80211: configuration of Bluetooth coexistence mode

>On Fri, 2013-02-22 at 10:08 +0100, Piotr Haber wrote:
>> Some devices share antenna/analog front end between Wifi
>> and Bluetooth. The hardware coexistence interface allows
>> them to do so, but there are situations when it would
>> be beneficial if software had a way to have influence on it
>> as well. It can be used to protect time sensitive
>> traffic in presence of Bluetooth voice stream,
>> for an example EAPOL handshake or DHCP negotiation.
>>
>> This patch adds new attribute to SET_WIPHY command
>> and a new field in struct wiphy to allow control of the
>> coexistence behavior. Devices that do not share resources
>> with Bluetooth can ignore this parameter.

> Apart from a few minor technical comments that I'll omit for now, I'm
> not sure what value this really has? EAPOL can already be "protected" by
> way of knowing when the station is marked authorized, and DHCP is pretty
> tricky because it could take "forever", might not be there at all, etc.
By "protect" I meant give Wifi a priority over BT so these time sensitive things 
can finish quicker/on first try, limiting the possibility of dropping packets because of BT 
using the medium.
This is supposed to be temporary and time limited, so if say DHCP finishes in the window 
we give it - great, if not the coexistence goes back to default behavior and Wifi traffic is
treated as usual. 

> What application would actually call this? I don't really see how it
> could be integrated like that.
For EAPOL wpa_supplicant might use it. For DHCP it could be used from enter/exit hooks
via iw or some other utility able to send nl messages.

This feature is styled after Android one.
There a Wifi state machine tries to "protect" DHCP traffic.
It uses extra wpa_supplicant command (DRIVER) with linked driver specific library.
Which means there can be only one wifi device and one needs to recompile wpa_supplicant 
to use another.
I wanted to make it more device independent.

Piotr

Re: [PATCH 1/2] [RFC] cfg80211: configuration of Bluetooth coexistence mode

[Johannes Berg]

On Fri, 2013-02-22 at 13:32 +0000, Piotr Haber wrote:

> > Apart from a few minor technical comments that I'll omit for now, I'm
> > not sure what value this really has? EAPOL can already be "protected" by
> > way of knowing when the station is marked authorized, and DHCP is pretty
> > tricky because it could take "forever", might not be there at all, etc.

> By "protect" I meant give Wifi a priority over BT so these time sensitive things 
> can finish quicker/on first try, limiting the possibility of dropping packets because of BT 
> using the medium.

I know :)

> This is supposed to be temporary and time limited, so if say DHCP finishes in the window 
> we give it - great, if not the coexistence goes back to default behavior and Wifi traffic is
> treated as usual. 

That's not even documented/implemented, the way I read the patch you'd
have to set it back manually.

> > What application would actually call this? I don't really see how it
> > could be integrated like that.

> For EAPOL wpa_supplicant might use it. For DHCP it could be used from enter/exit hooks
> via iw or some other utility able to send nl messages.

See that's the thing, I don't really see the point for EAPOL: you could
just as well start protecting when the association is done, and end it
when the station is marked authorized. That will have protected any
EAPOL (or other protocols for that matter) traffic.

Similarly, you could give it a certain timeout to protect DHCP traffic.
I guess the only thing that would seem necessary would be a notification
of "DHCP done" that would allow you to drop the protection right away.

> This feature is styled after Android one.

I know, I'm (vaguely) familiar with that.

> There a Wifi state machine tries to "protect" DHCP traffic.

Is there any *reason* for it though? Would it ever call it after the
connection is fully established?

To me this seems not very well thought out.

johannes

RE: [PATCH 1/2] [RFC] cfg80211: configuration of Bluetooth coexistence mode

[Piotr Haber]

> > This is supposed to be temporary and time limited, so if say DHCP finishes in the window
> > we give it - great, if not the coexistence goes back to default behavior and Wifi traffic is
> > treated as usual.

> That's not even documented/implemented, the way I read the patch you'd
> have to set it back manually.

You are right, we implement it this way in brcmfmac but it is not documented
in nl80211 change. I thought of DISABLED as a trigger (for timed boost)
and ENABLED as a way to notify that whoever requested it is done.
The interface could be made to reflect this "design"

> > > What application would actually call this? I don't really see how it
> > > could be integrated like that.

> > For EAPOL wpa_supplicant might use it. For DHCP it could be used from enter/exit hooks
> > via iw or some other utility able to send nl messages.

> See that's the thing, I don't really see the point for EAPOL: you could
> just as well start protecting when the association is done, and end it
> when the station is marked authorized. That will have protected any
> EAPOL (or other protocols for that matter) traffic.

That is true, this could be totally automatic.

> Similarly, you could give it a certain timeout to protect DHCP traffic.
> I guess the only thing that would seem necessary would be a notification
> of "DHCP done" that would allow you to drop the protection right away.

I guess that is the only reason we need this interface.
Still if we set the "protection" timeout to be reasonable it can do without
it...

> > This feature is styled after Android one.

> I know, I'm (vaguely) familiar with that.

> > There a Wifi state machine tries to "protect" DHCP traffic.

> Is there any *reason* for it though? Would it ever call it after the
> connection is fully established?

As for reason I can't tell, someone found one to implement it in Android :)
It is not used after connection is established.

Piotr