Bring over the initial static bluetooth coexistence configuration

for the WB195 combo NIC - an AR9285 w/ an AR3011 USB bluetooth NIC.

The AR3011 is wired up using a 3-wire coexistence scheme to the AR9285.

The code in if_ath_btcoex.c sets up the initial hardware mapping
and coexistence configuration.  There's nothing special about it -
it's static; it doesn't try to configure bluetooth / MAC traffic priorities
or try to figure out what's actually going on.  It's enough to stop basic
bluetooth traffic from causing traffic stalls and diassociation from
the wireless network.

To use this code, you must have the above NIC.  No, it won't work
for the AR9287+AR3012, nor the AR9485, AR9462 or AR955x combo cards.

Then you set a kernel hint before boot or before kldload, where 'X'
is the unit number of your AR9285 NIC:

# kenv hint.ath.X.btcoex_profile=wb195

This will then appear in your boot messages:

[100482] athX: Enabling WB195 BTCOEX

This code is going to evolve pretty quickly (well, depending upon my
spare time) so don't assume the btcoex API is going to stay stable.

In order to use the bluetooth side, you must also load in firmware using
ath3kfw and the binary firmware file (ath3k-1.fw in my case.)

Tested:

* AR9280, no interference
* WB195 - AR9285 + AR3011 combo; STA mode; basic bluetooth inquiries
  were enough to cause traffic stalls and disassociations.  This has
  stopped with the btcoex profile code.

TODO:

* Importantly - the AR9285 needs ASPM disabled if bluetooth coexistence
  is enabled.  No, I don't know why.  It's likely some kind of bug to do
  with the AR3011 sending bluetooth coexistence signals whilst the device
  is asleep.  Since we don't actually sleep the MAC just yet, it shouldn't
  be a problem.  That said, to be totally correct:

  + ASPM should be disabled - upon attach and wakeup
  + The PCIe powersave HAL code should never be called

  Look at what the ath9k driver does for inspiration.

* Add WB197 (AR9287+AR3012) support
* Add support for the AR9485, which is another combo like the AR9285
* The later NICs have a different signaling mechanism between the MAC
  and the bluetooth device; I haven't even begun to experiment with
  making that HAL code work.  But it should be a lot more automatic.

* The hardware can do much more interesting traffic weighting with
  bluetooth and wifi traffic.  None of this is currently used.
  Ideally someone would code up something to watch the bluetooth traffic
  GPIO (via an interrupt) and then watch it go high/low; then figure out
  what the bluetooth traffic is and adjust things appropriately.

* If I get the time I may add in some code to at least track this stuff
  and expose statistics.  But it's up to someone else to experiment with
  the bluetooth coexistence support and add the interesting stuff (like
  "real" detection of bulk, audio, etc bluetooth traffic patterns and
  change wifi parameters appropriately - eg, maximum aggregate length,
  transmit power, using quiet time to control TX duty cycle, etc.)

sys/conf/files

@@ -725,6 +725,8 @@ dev/ath/if_ath.c		optional ath \
 	compile-with "${NORMAL_C} -I$S/dev/ath"
 dev/ath/if_ath_beacon.c		optional ath \
 	compile-with "${NORMAL_C} -I$S/dev/ath"
+dev/ath/if_ath_btcoex.c		optional ath \
+	compile-with "${NORMAL_C} -I$S/dev/ath"
 dev/ath/if_ath_debug.c		optional ath \
 	compile-with "${NORMAL_C} -I$S/dev/ath"
 dev/ath/if_ath_keycache.c	optional ath \

sys/dev/ath/if_ath.c

@@ -111,6 +111,7 @@ __FBSDID("$FreeBSD$");
 #include <dev/ath/if_ath_rx_edma.h>
 #include <dev/ath/if_ath_tx_edma.h>
 #include <dev/ath/if_ath_beacon.h>
+#include <dev/ath/if_ath_btcoex.h>
 #include <dev/ath/if_ath_spectral.h>
 #include <dev/ath/if_athdfs.h>
 
@@ -521,6 +522,14 @@ ath_attach(u_int16_t devid, struct ath_softc *sc)
 		goto bad2;
 	}
 
+	/* Attach bluetooth coexistence module */
+	if (ath_btcoex_attach(sc) < 0) {
+		device_printf(sc->sc_dev,
+		    "%s: unable to attach bluetooth coexistence\n", __func__);
+		error = EIO;
+		goto bad2;
+	}
+
 	/* Start DFS processing tasklet */
 	TASK_INIT(&sc->sc_dfstask, 0, ath_dfs_tasklet, sc);
 
@@ -1029,6 +1038,7 @@ ath_detach(struct ath_softc *sc)
 #ifdef	ATH_DEBUG_ALQ
 	if_ath_alq_tidyup(&sc->sc_alq);
 #endif
+	ath_btcoex_detach(sc);
 	ath_spectral_detach(sc);
 	ath_dfs_detach(sc);
 	ath_desc_free(sc);
@@ -1588,6 +1598,11 @@ ath_resume(struct ath_softc *sc)
 	/* Let spectral at in case spectral is enabled */
 	ath_spectral_enable(sc, ic->ic_curchan);
 
+	/*
+	 * Let bluetooth coexistence at in case it's needed for this channel
+	 */
+	ath_btcoex_enable(sc, ic->ic_curchan);
+
 	/*
 	 * If we're doing TDMA, enforce the TXOP limitation for chips that
 	 * support it.
@@ -2044,6 +2059,11 @@ ath_init(void *arg)
 	/* Let spectral at in case spectral is enabled */
 	ath_spectral_enable(sc, ic->ic_curchan);
 
+	/*
+	 * Let bluetooth coexistence at in case it's needed for this channel
+	 */
+	ath_btcoex_enable(sc, ic->ic_curchan);
+
 	/*
 	 * If we're doing TDMA, enforce the TXOP limitation for chips that
 	 * support it.
@@ -2383,6 +2403,11 @@ ath_reset(struct ifnet *ifp, ATH_RESET_TYPE reset_type)
 	/* Let spectral at in case spectral is enabled */
 	ath_spectral_enable(sc, ic->ic_curchan);
 
+	/*
+	 * Let bluetooth coexistence at in case it's needed for this channel
+	 */
+	ath_btcoex_enable(sc, ic->ic_curchan);
+
 	/*
 	 * If we're doing TDMA, enforce the TXOP limitation for chips that
 	 * support it.
@@ -4945,6 +4970,12 @@ ath_chan_set(struct ath_softc *sc, struct ieee80211_channel *chan)
 		/* Let spectral at in case spectral is enabled */
 		ath_spectral_enable(sc, chan);
 
+		/*
+		 * Let bluetooth coexistence at in case it's needed for this
+		 * channel
+		 */
+		ath_btcoex_enable(sc, ic->ic_curchan);
+
 		/*
 		 * If we're doing TDMA, enforce the TXOP limitation for chips
 		 * that support it.

sys/dev/ath/if_ath_btcoex.c

@@ -0,0 +1,281 @@
+/*-
+ * Copyright (c) 2013 Adrian Chadd <adrian@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
+ *    redistribution must be conditioned upon including a substantially
+ *    similar Disclaimer requirement for further binary redistribution.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGES.
+ *
+ * $FreeBSD$
+ */
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+/*
+ * This implements some very basic bluetooth coexistence methods for
+ * the ath(4) hardware.
+ */
+#include "opt_ath.h"
+#include "opt_inet.h"
+#include "opt_wlan.h"
+
+#include <sys/param.h>
+#include <sys/systm.h> 
+#include <sys/sysctl.h>
+#include <sys/kernel.h>
+#include <sys/lock.h>
+#include <sys/mutex.h>
+#include <sys/errno.h>
+
+#include <machine/bus.h>
+#include <machine/resource.h>
+#include <sys/bus.h>
+
+#include <sys/socket.h>
+ 
+#include <net/if.h>
+#include <net/if_media.h>
+#include <net/if_arp.h>
+#include <net/ethernet.h>		/* XXX for ether_sprintf */
+
+#include <net80211/ieee80211_var.h>
+
+#include <net/bpf.h>
+
+#ifdef INET
+#include <netinet/in.h>
+#include <netinet/if_ether.h>
+#endif
+
+#include <dev/ath/if_athvar.h>
+#include <dev/ath/if_ath_btcoex.h>
+
+/*
+ * Initial AR9285 / (WB195) bluetooth coexistence settings,
+ * just for experimentation.
+ *
+ * Return 0 for OK; errno for error.
+ *
+ * XXX TODO: There needs to be a PCIe workaround to disable ASPM if
+ * bluetooth coexistence is enabled.
+ */
+static int
+ath_btcoex_cfg_wb195(struct ath_softc *sc)
+{
+	HAL_BT_COEX_INFO btinfo;
+	HAL_BT_COEX_CONFIG btconfig;
+	struct ath_hal *ah = sc->sc_ah;
+
+	if (! ath_hal_btcoex_supported(ah))
+		return (EINVAL);
+
+	bzero(&btinfo, sizeof(btinfo));
+	bzero(&btconfig, sizeof(btconfig));
+
+	device_printf(sc->sc_dev, "Enabling WB195 BTCOEX\n");
+
+	btinfo.bt_module = HAL_BT_MODULE_JANUS;
+	btinfo.bt_coex_config = HAL_BT_COEX_CFG_3WIRE;
+	/*
+	 * These are the three GPIO pins hooked up between the AR9285 and
+	 * the AR3011.
+	 */
+	btinfo.bt_gpio_bt_active = 6;
+	btinfo.bt_gpio_bt_priority = 7;
+	btinfo.bt_gpio_wlan_active = 5;
+	btinfo.bt_active_polarity = 1;	/* XXX not used */
+	btinfo.bt_single_ant = 1;	/* 1 antenna on ar9285 ? */
+	btinfo.bt_isolation = 0;	/* in dB, not used */
+
+	ath_hal_btcoex_set_info(ah, &btinfo);
+
+	btconfig.bt_time_extend = 0;
+	btconfig.bt_txstate_extend = 1;	/* true */
+	btconfig.bt_txframe_extend = 1;	/* true */
+	btconfig.bt_mode = HAL_BT_COEX_MODE_SLOTTED;
+	btconfig.bt_quiet_collision = 1;	/* true */
+	btconfig.bt_rxclear_polarity = 1;	/* true */
+	btconfig.bt_priority_time = 2;
+	btconfig.bt_first_slot_time = 5;
+	btconfig.bt_hold_rxclear = 1;	/* true */
+
+	ath_hal_btcoex_set_config(ah, &btconfig);
+
+	/*
+	 * Enable antenna diversity.
+	 */
+	ath_hal_btcoex_set_parameter(ah, HAL_BT_COEX_ANTENNA_DIVERSITY, 1);
+
+	return (0);
+}
+
+#if 0
+/*
+ * When using bluetooth coexistence, ASPM needs to be disabled
+ * otherwise the sleeping interferes with the bluetooth (USB)
+ * operation and the MAC sleep/wakeup hardware.
+ */
+static int
+ath_btcoex_aspm_wb195(struct ath_softc *sc)
+{
+
+	/* XXX TODO: clear device ASPM L0S and L1 */
+	/* XXX TODO: clear _parent_ ASPM L0S and L1 */
+}
+#endif
+
+/*
+ * Methods which are required
+ */
+
+/*
+ * Attach btcoex to the given interface
+ */
+int
+ath_btcoex_attach(struct ath_softc *sc)
+{
+	int ret;
+	struct ath_hal *ah = sc->sc_ah;
+	const char *profname;
+
+	/*
+	 * No chipset bluetooth coexistence? Then do nothing.
+	 */
+	if (! ath_hal_btcoex_supported(ah))
+		return (0);
+
+	/*
+	 * Look at the hints to determine which bluetooth
+	 * profile to configure.
+	 */
+	ret = resource_string_value(device_get_name(sc->sc_dev),
+	    device_get_unit(sc->sc_dev),
+	    "btcoex_profile",
+	    &profname);
+	if (ret != 0) {
+		/* nothing to do */
+		return (0);
+	}
+
+	if (strncmp(profname, "wb195", 5) == 0) {
+		ret = ath_btcoex_cfg_wb195(sc);
+	} else {
+		return (0);
+	}
+
+	/*
+	 * Propagate up failure from the actual attach phase.
+	 */
+	if (ret != 0)
+		return (ret);
+
+	return (0);
+}
+
+/*
+ * Detach btcoex from the given interface
+ */
+int
+ath_btcoex_detach(struct ath_softc *sc)
+{
+
+	return (0);
+}
+
+/*
+ * Configure or disable bluetooth coexistence on the given channel.
+ *
+ * For AR9285/AR9287/AR9485, we'll never see a 5GHz channel, so we just
+ * assume bluetooth coexistence is always on.
+ *
+ * For AR9462, we may see a 5GHz channel; bluetooth coexistence should
+ * not be enabled on those channels.
+ */
+int
+ath_btcoex_enable(struct ath_softc *sc, const struct ieee80211_channel *chan)
+{
+
+	return (0);
+}
+
+/*
+ * Handle ioctl requests from the diagnostic interface.
+ *
+ * The initial part of this code resembles ath_ioctl_diag();
+ * it's likely a good idea to reduce duplication between
+ * these two routines.
+ */
+int
+ath_btcoex_ioctl(struct ath_softc *sc, struct ath_diag *ad)
+{
+	unsigned int id = ad->ad_id & ATH_DIAG_ID;
+	void *indata = NULL;
+	void *outdata = NULL;
+	u_int32_t insize = ad->ad_in_size;
+	u_int32_t outsize = ad->ad_out_size;
+	int error = 0;
+//	int val;
+
+	if (ad->ad_id & ATH_DIAG_IN) {
+		/*
+		 * Copy in data.
+		 */
+		indata = malloc(insize, M_TEMP, M_NOWAIT);
+		if (indata == NULL) {
+			error = ENOMEM;
+			goto bad;
+		}
+		error = copyin(ad->ad_in_data, indata, insize);
+		if (error)
+			goto bad;
+	}
+	if (ad->ad_id & ATH_DIAG_DYN) {
+		/*
+		 * Allocate a buffer for the results (otherwise the HAL
+		 * returns a pointer to a buffer where we can read the
+		 * results).  Note that we depend on the HAL leaving this
+		 * pointer for us to use below in reclaiming the buffer;
+		 * may want to be more defensive.
+		 */
+		outdata = malloc(outsize, M_TEMP, M_NOWAIT);
+		if (outdata == NULL) {
+			error = ENOMEM;
+			goto bad;
+		}
+	}
+	switch (id) {
+		default:
+			error = EINVAL;
+	}
+	if (outsize < ad->ad_out_size)
+		ad->ad_out_size = outsize;
+	if (outdata && copyout(outdata, ad->ad_out_data, ad->ad_out_size))
+		error = EFAULT;
+bad:
+	if ((ad->ad_id & ATH_DIAG_IN) && indata != NULL)
+		free(indata, M_TEMP);
+	if ((ad->ad_id & ATH_DIAG_DYN) && outdata != NULL)
+		free(outdata, M_TEMP);
+	return (error);
+}
+

sys/dev/ath/if_ath_btcoex.h

@@ -0,0 +1,40 @@
+/*-
+ * Copyright (c) 2013 Adrian Chadd <adrian@FreeBSD.org>
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer,
+ *    without modification.
+ * 2. Redistributions in binary form must reproduce at minimum a disclaimer
+ *    similar to the "NO WARRANTY" disclaimer below ("Disclaimer") and any
+ *    redistribution must be conditioned upon including a substantially
+ *    similar Disclaimer requirement for further binary redistribution.
+ *
+ * NO WARRANTY
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+ * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+ * LIMITED TO, THE IMPLIED WARRANTIES OF NONINFRINGEMENT, MERCHANTIBILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDERS OR CONTRIBUTORS BE LIABLE FOR SPECIAL, EXEMPLARY,
+ * OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
+ * IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
+ * THE POSSIBILITY OF SUCH DAMAGES.
+ *
+ * $FreeBSD$
+ */
+#ifndef	__IF_ATH_BTCOEX_H__
+#define	__IF_ATH_BTCOEX_H__
+
+extern	int ath_btcoex_attach(struct ath_softc *sc);
+extern	int ath_btcoex_detach(struct ath_softc *sc);
+extern	int ath_btcoex_ioctl(struct ath_softc *sc, struct ath_diag *ad);
+extern	int ath_btcoex_enable(struct ath_softc *sc,
+	    const struct ieee80211_channel *ch);
+
+#endif	/* __IF_ATH_BTCOEX_H__ */

sys/modules/ath/Makefile

@@ -38,6 +38,7 @@ KMOD=	if_ath
 SRCS=	if_ath.c if_ath_alq.c if_ath_debug.c if_ath_keycache.c if_ath_sysctl.c
 SRCS+=	if_ath_tx.c if_ath_tx_ht.c if_ath_led.c if_ath_rx.c if_ath_tdma.c
 SRCS+=	if_ath_beacon.c if_ath_rx_edma.c if_ath_tx_edma.c if_ath_spectral.c
+SRCS+=	if_ath_btcoex.c
 # NB: v3 eeprom support used by both AR5211 and AR5212; just include it
 SRCS+=	ah_osdep.c ah.c ah_regdomain.c ah_eeprom_v3.c
 SRCS+=	device_if.h bus_if.h pci_if.h opt_inet.h opt_ath.h opt_ah.h opt_wlan.h