brcmfmac: support critical protocol API for DHCP

Adds support for the critical protocol API provided by nl80211
which gives Wifi traffic priority over a Bluetooth (e)SCO connection
and disables scanning during DCHP negotiation.

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>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 497 insertions, 0 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/btcoex.c b/drivers/net/wireless/brcm80211/brcmfmac/btcoex.c
new file mode 100644
index 000000000000..0cb591b050b3
--- /dev/null
+++ b/drivers/net/wireless/brcm80211/brcmfmac/btcoex.c
@@ -0,0 +1,497 @@
+/*
+ * 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_BTCOEX_OPPR_WIN_TIME   2000
+
+/* 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
+ * @vif: interface for which request was done.
+ * @timer: timer for DHCP state machine
+ * @timeout: configured timeout.
+ * @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
+ * @reg66: saved value of btc_params 66
+ * @reg41: saved value of btc_params 41
+ * @reg68: saved value of btc_params 68
+ * @saved_regs_part1: flag indicating regs 66,41,68
+ *	have been saved
+ * @reg51: saved value of btc_params 51
+ * @reg64: saved value of btc_params 64
+ * @reg65: saved value of btc_params 65
+ * @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 brcmf_cfg80211_vif *vif;
+	struct timer_list timer;
+	u16 timeout;
+	bool timer_on;
+	bool dhcp_done;
+	enum brcmf_btcoex_state bt_state;
+	struct work_struct work;
+	struct brcmf_cfg80211_info *cfg;
+	u32 reg66;
+	u32 reg41;
+	u32 reg68;
+	bool saved_regs_part1;
+	u32 reg50;
+	u32 reg51;
+	u32 reg64;
+	u32 reg65;
+	u32 reg71;
+	bool saved_regs_part2;
+};
+
+/**
+ * brcmf_btcoex_params_write() - write btc_params firmware variable
+ * @ifp: interface
+ * @addr: btc_params register number
+ * @data: data to write
+ */
+static s32 brcmf_btcoex_params_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_params_read() - read btc_params firmware variable
+ * @ifp: interface
+ * @addr: btc_params register number
+ * @data: read data
+ */
+static s32 brcmf_btcoex_params_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
+ * @btci: 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 *btci,
+				    bool trump_sco)
+{
+	struct brcmf_if *ifp = btci->cfg->pub->iflist[0];
+
+	if (trump_sco && !btci->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_params_read(ifp, 50, &btci->reg50);
+		brcmf_btcoex_params_read(ifp, 51, &btci->reg51);
+		brcmf_btcoex_params_read(ifp, 64, &btci->reg64);
+		brcmf_btcoex_params_read(ifp, 65, &btci->reg65);
+		brcmf_btcoex_params_read(ifp, 71, &btci->reg71);
+
+		btci->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",
+			  btci->reg50, btci->reg51, btci->reg64,
+			  btci->reg65, btci->reg71);
+
+		/* pacify the eSco   */
+		brcmf_btcoex_params_write(ifp, 50, BRCMF_BT_DHCP_REG50);
+		brcmf_btcoex_params_write(ifp, 51, BRCMF_BT_DHCP_REG51);
+		brcmf_btcoex_params_write(ifp, 64, BRCMF_BT_DHCP_REG64);
+		brcmf_btcoex_params_write(ifp, 65, BRCMF_BT_DHCP_REG65);
+		brcmf_btcoex_params_write(ifp, 71, BRCMF_BT_DHCP_REG71);
+
+	} else if (btci->saved_regs_part2) {
+		/* restore previously saved bt params */
+		brcmf_dbg(TRACE, "Do new SCO/eSCO coex algo {restore}\n");
+		brcmf_btcoex_params_write(ifp, 50, btci->reg50);
+		brcmf_btcoex_params_write(ifp, 51, btci->reg51);
+		brcmf_btcoex_params_write(ifp, 64, btci->reg64);
+		brcmf_btcoex_params_write(ifp, 65, btci->reg65);
+		brcmf_btcoex_params_write(ifp, 71, btci->reg71);
+
+		brcmf_dbg(TRACE,
+			  "restored bt_params[50,51,64,65,71]: 0x%x 0x%x 0x%x 0x%x 0x%x\n",
+			  btci->reg50, btci->reg51, btci->reg64,
+			  btci->reg65, btci->reg71);
+
+		btci->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_params_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;
+		}
+	}
+	brcmf_dbg(TRACE, "exit: result=%d\n", res);
+	return res;
+}
+
+/**
+ * btcmf_btcoex_save_part1() - save first step parameters.
+ */
+static void btcmf_btcoex_save_part1(struct brcmf_btcoex_info *btci)
+{
+	struct brcmf_if *ifp = btci->vif->ifp;
+
+	if (!btci->saved_regs_part1) {
+		/* Retrieve and save original reg value */
+		brcmf_btcoex_params_read(ifp, 66, &btci->reg66);
+		brcmf_btcoex_params_read(ifp, 41, &btci->reg41);
+		brcmf_btcoex_params_read(ifp, 68, &btci->reg68);
+		btci->saved_regs_part1 = true;
+		brcmf_dbg(TRACE,
+			  "saved btc_params regs (66,41,68) 0x%x 0x%x 0x%x\n",
+			  btci->reg66, btci->reg41,
+			  btci->reg68);
+	}
+}
+
+/**
+ * brcmf_btcoex_restore_part1() - restore first step parameters.
+ */
+static void brcmf_btcoex_restore_part1(struct brcmf_btcoex_info *btci)
+{
+	struct brcmf_if *ifp;
+
+	if (btci->saved_regs_part1) {
+		btci->saved_regs_part1 = false;
+		ifp = btci->vif->ifp;
+		brcmf_btcoex_params_write(ifp, 66, btci->reg66);
+		brcmf_btcoex_params_write(ifp, 41, btci->reg41);
+		brcmf_btcoex_params_write(ifp, 68, btci->reg68);
+		brcmf_dbg(TRACE,
+			  "restored btc_params regs {66,41,68} 0x%x 0x%x 0x%x\n",
+			  btci->reg66, btci->reg41,
+			  btci->reg68);
+	}
+}
+
+/**
+ * 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 *btci;
+	btci = container_of(work, struct brcmf_btcoex_info, work);
+	if (btci->timer_on) {
+		btci->timer_on = false;
+		del_timer_sync(&btci->timer);
+	}
+
+	switch (btci->bt_state) {
+	case BRCMF_BT_DHCP_START:
+		/* DHCP started provide OPPORTUNITY window
+		   to get DHCP address
+		*/
+		brcmf_dbg(TRACE, "DHCP started\n");
+		btci->bt_state = BRCMF_BT_DHCP_OPPR_WIN;
+		if (btci->timeout < BRCMF_BTCOEX_OPPR_WIN_TIME) {
+			mod_timer(&btci->timer, btci->timer.expires);
+		} else {
+			btci->timeout -= BRCMF_BTCOEX_OPPR_WIN_TIME;
+			mod_timer(&btci->timer,
+				  jiffies +
+				  msecs_to_jiffies(BRCMF_BTCOEX_OPPR_WIN_TIME));
+		}
+		btci->timer_on = true;
+		break;
+
+	case BRCMF_BT_DHCP_OPPR_WIN:
+		if (btci->dhcp_done) {
+			brcmf_dbg(TRACE, "DHCP done before T1 expiration\n");
+			goto idle;
+		}
+
+		/* DHCP is not over yet, start lowering BT priority */
+		brcmf_dbg(TRACE, "DHCP T1:%d expired\n",
+			  BRCMF_BTCOEX_OPPR_WIN_TIME);
+		brcmf_btcoex_boost_wifi(btci, true);
+
+		btci->bt_state = BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT;
+		mod_timer(&btci->timer,
+			  jiffies + msecs_to_jiffies(btci->timeout));
+		btci->timer_on = true;
+		break;
+
+	case BRCMF_BT_DHCP_FLAG_FORCE_TIMEOUT:
+		if (btci->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_TIMEOUT);
+
+		goto idle;
+
+	default:
+		brcmf_err("invalid state=%d !!!\n", btci->bt_state);
+		goto idle;
+	}
+
+	return;
+
+idle:
+	btci->bt_state = BRCMF_BT_DHCP_IDLE;
+	btci->timer_on = false;
+	brcmf_btcoex_boost_wifi(btci, false);
+	cfg80211_crit_proto_stopped(&btci->vif->wdev, GFP_KERNEL);
+	brcmf_btcoex_restore_part1(btci);
+	btci->vif = NULL;
+}
+
+/**
+ * brcmf_btcoex_attach() - initialize BT coex data
+ * @cfg: driver private cfg80211 data
+ *
+ * return: 0 on success
+ */
+int brcmf_btcoex_attach(struct brcmf_cfg80211_info *cfg)
+{
+	struct brcmf_btcoex_info *btci = NULL;
+	brcmf_dbg(TRACE, "enter\n");
+
+	btci = kmalloc(sizeof(struct brcmf_btcoex_info), GFP_KERNEL);
+	if (!btci)
+		return -ENOMEM;
+
+	btci->bt_state = BRCMF_BT_DHCP_IDLE;
+
+	/* Set up timer for BT  */
+	btci->timer_on = false;
+	btci->timeout = BRCMF_BTCOEX_OPPR_WIN_TIME;
+	init_timer(&btci->timer);
+	btci->timer.data = (ulong)btci;
+	btci->timer.function = brcmf_btcoex_timerfunc;
+	btci->cfg = cfg;
+	btci->saved_regs_part1 = false;
+	btci->saved_regs_part2 = false;
+
+	INIT_WORK(&btci->work, brcmf_btcoex_handler);
+
+	cfg->btcoex = btci;
+	return 0;
+}
+
+/**
+ * brcmf_btcoex_detach - clean BT coex data
+ * @cfg: driver private cfg80211 data
+ */
+void brcmf_btcoex_detach(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);
+
+	brcmf_btcoex_boost_wifi(cfg->btcoex, false);
+	brcmf_btcoex_restore_part1(cfg->btcoex);
+
+	kfree(cfg->btcoex);
+	cfg->btcoex = NULL;
+}
+
+static void brcmf_btcoex_dhcp_start(struct brcmf_btcoex_info *btci)
+{
+	struct brcmf_if *ifp = btci->vif->ifp;
+
+	btcmf_btcoex_save_part1(btci);
+	/* set new regs values */
+	brcmf_btcoex_params_write(ifp, 66, BRCMF_BT_DHCP_REG66);
+	brcmf_btcoex_params_write(ifp, 41, BRCMF_BT_DHCP_REG41);
+	brcmf_btcoex_params_write(ifp, 68, BRCMF_BT_DHCP_REG68);
+	btci->dhcp_done = false;
+	btci->bt_state = BRCMF_BT_DHCP_START;
+	schedule_work(&btci->work);
+	brcmf_dbg(TRACE, "enable BT DHCP Timer\n");
+}
+
+static void brcmf_btcoex_dhcp_end(struct brcmf_btcoex_info *btci)
+{
+	/* Stop any bt timer because DHCP session is done */
+	btci->dhcp_done = true;
+	if (btci->timer_on) {
+		brcmf_dbg(TRACE, "disable BT DHCP Timer\n");
+		btci->timer_on = false;
+		del_timer_sync(&btci->timer);
+
+		/* schedule worker if transition to IDLE is needed */
+		if (btci->bt_state != BRCMF_BT_DHCP_IDLE) {
+			brcmf_dbg(TRACE, "bt_state:%d\n",
+				  btci->bt_state);
+			schedule_work(&btci->work);
+		}
+	} else {
+		/* Restore original values */
+		brcmf_btcoex_restore_part1(btci);
+	}
+}
+
+/**
+ * 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_vif *vif,
+			  enum brcmf_btcoex_mode mode, u16 duration)
+{
+	struct brcmf_cfg80211_info *cfg = wiphy_priv(vif->wdev.wiphy);
+	struct brcmf_btcoex_info *btci = cfg->btcoex;
+	struct brcmf_if *ifp = cfg->pub->iflist[0];
+
+	switch (mode) {
+	case BRCMF_BTCOEX_DISABLED:
+		brcmf_dbg(TRACE, "DHCP session starts\n");
+		if (btci->bt_state != BRCMF_BT_DHCP_IDLE)
+			return -EBUSY;
+		/* Start BT timer only for SCO connection */
+		if (brcmf_btcoex_is_sco_active(ifp)) {
+			btci->timeout = duration;
+			btci->vif = vif;
+			brcmf_btcoex_dhcp_start(btci);
+		}
+		break;
+
+	case BRCMF_BTCOEX_ENABLED:
+		brcmf_dbg(TRACE, "DHCP session ends\n");
+		if (btci->bt_state != BRCMF_BT_DHCP_IDLE &&
+		    vif == btci->vif) {
+			brcmf_btcoex_dhcp_end(btci);
+		}
+		break;
+	default:
+		brcmf_dbg(TRACE, "Unknown mode, ignored\n");
+	}
+	return 0;
+}