[PATCH v2] wl1251: add sysfs interface for bluetooth coexistence mode configuration

[Pali RohÃr]

Port the bt_coex_mode sysfs interface from wl1251 driver version included
in the Maemo Fremantle kernel to allow bt-coexistence mode configuration.
This enables userspace applications to set one of the modes
WL1251_BT_COEX_OFF, WL1251_BT_COEX_ENABLE and WL1251_BT_COEX_MONOAUDIO.
The default mode is WL1251_BT_COEX_OFF.
It should be noted that this driver always enabled bt-coexistence before
and enabled bt-coexistence directly affects the receiving performance,
rendering it unusable in some low-signal situations. Especially monitor
mode is affected very badly with bt-coexistence enabled.

Signed-off-by: David Gnedt <david.gnedt@xxxxxxxxxxx>
Signed-off-by: Pali RohÃr <pali.rohar@xxxxxxxxx>
---
I'm resending this patch for review again as after two years there is no
nl80211 interface for bt coex and wl1251 on Nokia N900 needs it. Once
there will be common interface for bt coex I can rewrite my patches, but
I do not want to wait another 2 years...

Changes:
In v2 is sysfs node attached directly to wl1251 device instead of creating
new platform device for sysfs node. So sysfs node is now available at:
/sys/class/net/wlan0/device/bt_coex_mode
---
 drivers/net/wireless/ti/wl1251/acx.c    |   43 ++++++++++++++--
 drivers/net/wireless/ti/wl1251/acx.h    |    8 +--
 drivers/net/wireless/ti/wl1251/init.c   |    6 +--
 drivers/net/wireless/ti/wl1251/main.c   |   84 +++++++++++++++++++++++++++++++
 drivers/net/wireless/ti/wl1251/wl1251.h |    8 +++
 5 files changed, 137 insertions(+), 12 deletions(-)

diff --git a/drivers/net/wireless/ti/wl1251/acx.c b/drivers/net/wireless/ti/wl1251/acx.c
index d6fbdda..a119d77 100644
--- a/drivers/net/wireless/ti/wl1251/acx.c
+++ b/drivers/net/wireless/ti/wl1251/acx.c
@@ -539,7 +539,7 @@ out:
 	return ret;
 }
 
-int wl1251_acx_sg_enable(struct wl1251 *wl)
+int wl1251_acx_sg_enable(struct wl1251 *wl, u8 mode)
 {
 	struct acx_bt_wlan_coex *pta;
 	int ret;
@@ -550,7 +550,7 @@ int wl1251_acx_sg_enable(struct wl1251 *wl)
 	if (!pta)
 		return -ENOMEM;
 
-	pta->enable = SG_ENABLE;
+	pta->enable = mode;
 
 	ret = wl1251_cmd_configure(wl, ACX_SG_ENABLE, pta, sizeof(*pta));
 	if (ret < 0) {
@@ -563,7 +563,7 @@ out:
 	return ret;
 }
 
-int wl1251_acx_sg_cfg(struct wl1251 *wl)
+int wl1251_acx_sg_cfg(struct wl1251 *wl, u16 wake_up_beacon)
 {
 	struct acx_bt_wlan_coex_param *param;
 	int ret;
@@ -586,7 +586,7 @@ int wl1251_acx_sg_cfg(struct wl1251 *wl)
 	param->wlan_cycle_fast = PTA_CYCLE_TIME_FAST_DEF;
 	param->bt_anti_starvation_period = PTA_ANTI_STARVE_PERIOD_DEF;
 	param->next_bt_lp_packet = PTA_TIMEOUT_NEXT_BT_LP_PACKET_DEF;
-	param->wake_up_beacon = PTA_TIME_BEFORE_BEACON_DEF;
+	param->wake_up_beacon = wake_up_beacon;
 	param->hp_dm_max_guard_time = PTA_HPDM_MAX_TIME_DEF;
 	param->next_wlan_packet = PTA_TIME_OUT_NEXT_WLAN_DEF;
 	param->antenna_type = PTA_ANTENNA_TYPE_DEF;
@@ -615,6 +615,41 @@ out:
 	return ret;
 }
 
+int wl1251_acx_sg_configure(struct wl1251 *wl, bool force)
+{
+	int ret;
+
+	if (wl->state == WL1251_STATE_OFF && !force)
+		return 0;
+
+	switch (wl->bt_coex_mode) {
+	case WL1251_BT_COEX_OFF:
+		ret = wl1251_acx_sg_enable(wl, SG_DISABLE);
+		if (ret)
+			break;
+		ret = wl1251_acx_sg_cfg(wl, 0);
+		break;
+	case WL1251_BT_COEX_ENABLE:
+		ret = wl1251_acx_sg_enable(wl, SG_ENABLE);
+		if (ret)
+			break;
+		ret = wl1251_acx_sg_cfg(wl, PTA_TIME_BEFORE_BEACON_DEF);
+		break;
+	case WL1251_BT_COEX_MONOAUDIO:
+		ret = wl1251_acx_sg_enable(wl, SG_ENABLE);
+		if (ret)
+			break;
+		ret = wl1251_acx_sg_cfg(wl, PTA_TIME_BEFORE_BEACON_MONO_AUDIO);
+		break;
+	default:
+		wl1251_error("Invalid BT co-ex mode!");
+		ret = -EOPNOTSUPP;
+		break;
+	}
+
+	return ret;
+}
+
 int wl1251_acx_cca_threshold(struct wl1251 *wl)
 {
 	struct acx_energy_detection *detection;
diff --git a/drivers/net/wireless/ti/wl1251/acx.h b/drivers/net/wireless/ti/wl1251/acx.h
index 2bdec38..820573c 100644
--- a/drivers/net/wireless/ti/wl1251/acx.h
+++ b/drivers/net/wireless/ti/wl1251/acx.h
@@ -558,7 +558,8 @@ struct acx_bt_wlan_coex {
 #define PTA_ANTI_STARVE_PERIOD_DEF	  (500)
 #define PTA_ANTI_STARVE_NUM_CYCLE_DEF	  (4)
 #define PTA_ALLOW_PA_SD_DEF		  (1)
-#define PTA_TIME_BEFORE_BEACON_DEF	  (6300)
+#define PTA_TIME_BEFORE_BEACON_DEF	  (500)
+#define PTA_TIME_BEFORE_BEACON_MONO_AUDIO (6300)
 #define PTA_HPDM_MAX_TIME_DEF		  (1600)
 #define PTA_TIME_OUT_NEXT_WLAN_DEF	  (2550)
 #define PTA_AUTO_MODE_NO_CTS_DEF	  (0)
@@ -1470,8 +1471,9 @@ int wl1251_acx_rts_threshold(struct wl1251 *wl, u16 rts_threshold);
 int wl1251_acx_beacon_filter_opt(struct wl1251 *wl, bool enable_filter);
 int wl1251_acx_beacon_filter_table(struct wl1251 *wl);
 int wl1251_acx_conn_monit_params(struct wl1251 *wl);
-int wl1251_acx_sg_enable(struct wl1251 *wl);
-int wl1251_acx_sg_cfg(struct wl1251 *wl);
+int wl1251_acx_sg_enable(struct wl1251 *wl, u8 mode);
+int wl1251_acx_sg_cfg(struct wl1251 *wl, u16 wake_up_beacon);
+int wl1251_acx_sg_configure(struct wl1251 *wl, bool force);
 int wl1251_acx_cca_threshold(struct wl1251 *wl);
 int wl1251_acx_bcn_dtim_options(struct wl1251 *wl);
 int wl1251_acx_aid(struct wl1251 *wl, u16 aid);
diff --git a/drivers/net/wireless/ti/wl1251/init.c b/drivers/net/wireless/ti/wl1251/init.c
index 1d799bf..f8a2ea9 100644
--- a/drivers/net/wireless/ti/wl1251/init.c
+++ b/drivers/net/wireless/ti/wl1251/init.c
@@ -162,11 +162,7 @@ int wl1251_hw_init_pta(struct wl1251 *wl)
 {
 	int ret;
 
-	ret = wl1251_acx_sg_enable(wl);
-	if (ret < 0)
-		return ret;
-
-	ret = wl1251_acx_sg_cfg(wl);
+	ret = wl1251_acx_sg_configure(wl, true);
 	if (ret < 0)
 		return ret;
 
diff --git a/drivers/net/wireless/ti/wl1251/main.c b/drivers/net/wireless/ti/wl1251/main.c
index cd47779..8f53e43 100644
--- a/drivers/net/wireless/ti/wl1251/main.c
+++ b/drivers/net/wireless/ti/wl1251/main.c
@@ -1383,6 +1383,77 @@ static const struct ieee80211_ops wl1251_ops = {
 	.get_survey = wl1251_op_get_survey,
 };
 
+static ssize_t wl1251_sysfs_show_bt_coex_mode(struct device *dev,
+					      struct device_attribute *attr,
+					      char *buf)
+{
+	struct wl1251 *wl = dev_get_drvdata(dev);
+	ssize_t len;
+
+	/* FIXME: what's the maximum length of buf? page size?*/
+	len = 500;
+
+	mutex_lock(&wl->mutex);
+	len = snprintf(buf, len, "%d\n\n%d - off\n%d - on\n%d - monoaudio\n",
+		       wl->bt_coex_mode,
+		       WL1251_BT_COEX_OFF,
+		       WL1251_BT_COEX_ENABLE,
+		       WL1251_BT_COEX_MONOAUDIO);
+	mutex_unlock(&wl->mutex);
+
+	return len;
+}
+
+static ssize_t wl1251_sysfs_store_bt_coex_mode(struct device *dev,
+					       struct device_attribute *attr,
+					       const char *buf, size_t count)
+{
+	struct wl1251 *wl = dev_get_drvdata(dev);
+	unsigned long res;
+	int ret;
+
+	ret = kstrtoul(buf, 10, &res);
+
+	if (ret < 0) {
+		wl1251_warning("incorrect value written to bt_coex_mode");
+		return count;
+	}
+
+	mutex_lock(&wl->mutex);
+
+	if (res == wl->bt_coex_mode)
+		goto out;
+
+	switch (res) {
+	case WL1251_BT_COEX_OFF:
+	case WL1251_BT_COEX_ENABLE:
+	case WL1251_BT_COEX_MONOAUDIO:
+		wl->bt_coex_mode = res;
+		break;
+	default:
+		wl1251_warning("incorrect value written to bt_coex_mode");
+		goto out;
+	}
+
+	if (wl->state == WL1251_STATE_OFF)
+		goto out;
+
+	ret = wl1251_ps_elp_wakeup(wl);
+	if (ret < 0)
+		goto out;
+
+	wl1251_acx_sg_configure(wl, false);
+	wl1251_ps_elp_sleep(wl);
+
+out:
+	mutex_unlock(&wl->mutex);
+	return count;
+}
+
+static DEVICE_ATTR(bt_coex_mode, S_IRUGO | S_IWUSR,
+		   wl1251_sysfs_show_bt_coex_mode,
+		   wl1251_sysfs_store_bt_coex_mode);
+
 static int wl1251_read_eeprom_byte(struct wl1251 *wl, off_t offset, u8 *data)
 {
 	unsigned long timeout;
@@ -1467,6 +1538,7 @@ static int wl1251_register_hw(struct wl1251 *wl)
 
 int wl1251_init_ieee80211(struct wl1251 *wl)
 {
+	struct device *dev = wiphy_dev(wl->hw->wiphy);
 	int ret;
 
 	/* The tx descriptor buffer and the TKIP space */
@@ -1493,6 +1565,13 @@ int wl1251_init_ieee80211(struct wl1251 *wl)
 	if (ret)
 		goto out;
 
+	/* Create sysfs file to control bt coex state */
+	ret = device_create_file(dev, &dev_attr_bt_coex_mode);
+	if (ret < 0) {
+		wl1251_error("failed to create sysfs file bt_coex_mode");
+		goto out;
+	}
+
 	wl1251_debugfs_init(wl);
 	wl1251_notice("initialized");
 
@@ -1549,6 +1628,7 @@ struct ieee80211_hw *wl1251_alloc_hw(void)
 	wl->beacon_int = WL1251_DEFAULT_BEACON_INT;
 	wl->dtim_period = WL1251_DEFAULT_DTIM_PERIOD;
 	wl->vif = NULL;
+	wl->bt_coex_mode = WL1251_BT_COEX_OFF;
 
 	for (i = 0; i < FW_TX_CMPLT_BLOCK_SIZE; i++)
 		wl->tx_frames[i] = NULL;
@@ -1584,6 +1664,10 @@ EXPORT_SYMBOL_GPL(wl1251_alloc_hw);
 
 int wl1251_free_hw(struct wl1251 *wl)
 {
+	struct device *dev = wiphy_dev(wl->hw->wiphy);
+
+	device_remove_file(dev, &dev_attr_bt_coex_mode);
+
 	ieee80211_unregister_hw(wl->hw);
 
 	wl1251_debugfs_exit(wl);
diff --git a/drivers/net/wireless/ti/wl1251/wl1251.h b/drivers/net/wireless/ti/wl1251/wl1251.h
index 16dae52..b8b7ab7 100644
--- a/drivers/net/wireless/ti/wl1251/wl1251.h
+++ b/drivers/net/wireless/ti/wl1251/wl1251.h
@@ -258,6 +258,12 @@ struct wl1251_debugfs {
 	struct dentry *excessive_retries;
 };
 
+enum wl1251_bt_coex_mode {
+	WL1251_BT_COEX_OFF,
+	WL1251_BT_COEX_ENABLE,
+	WL1251_BT_COEX_MONOAUDIO
+};
+
 struct wl1251_if_operations {
 	void (*read)(struct wl1251 *wl, int addr, void *buf, size_t len);
 	void (*write)(struct wl1251 *wl, int addr, void *buf, size_t len);
@@ -394,6 +400,8 @@ struct wl1251 {
 
 	struct ieee80211_vif *vif;
 
+	enum wl1251_bt_coex_mode bt_coex_mode;
+
 	u32 chip_id;
 	char fw_ver[21];
 
-- 
1.7.9.5

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