drivers/net/wireless/ath/ath9k/wmi.c - linux - Git at Google

 /*
  * Copyright (c) 2010-2011 Atheros Communications Inc.
  *
  * 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 "htc.h"

 static const char *wmi_cmd_to_name(enum wmi_cmd_id wmi_cmd)
 {
 	switch (wmi_cmd) {
 	case WMI_ECHO_CMDID:
 		return "WMI_ECHO_CMDID";
 	case WMI_ACCESS_MEMORY_CMDID:
 		return "WMI_ACCESS_MEMORY_CMDID";
 	case WMI_GET_FW_VERSION:
 		return "WMI_GET_FW_VERSION";
 	case WMI_DISABLE_INTR_CMDID:
 		return "WMI_DISABLE_INTR_CMDID";
 	case WMI_ENABLE_INTR_CMDID:
 		return "WMI_ENABLE_INTR_CMDID";
 	case WMI_ATH_INIT_CMDID:
 		return "WMI_ATH_INIT_CMDID";
 	case WMI_ABORT_TXQ_CMDID:
 		return "WMI_ABORT_TXQ_CMDID";
 	case WMI_STOP_TX_DMA_CMDID:
 		return "WMI_STOP_TX_DMA_CMDID";
 	case WMI_ABORT_TX_DMA_CMDID:
 		return "WMI_ABORT_TX_DMA_CMDID";
 	case WMI_DRAIN_TXQ_CMDID:
 		return "WMI_DRAIN_TXQ_CMDID";
 	case WMI_DRAIN_TXQ_ALL_CMDID:
 		return "WMI_DRAIN_TXQ_ALL_CMDID";
 	case WMI_START_RECV_CMDID:
 		return "WMI_START_RECV_CMDID";
 	case WMI_STOP_RECV_CMDID:
 		return "WMI_STOP_RECV_CMDID";
 	case WMI_FLUSH_RECV_CMDID:
 		return "WMI_FLUSH_RECV_CMDID";
 	case WMI_SET_MODE_CMDID:
 		return "WMI_SET_MODE_CMDID";
 	case WMI_NODE_CREATE_CMDID:
 		return "WMI_NODE_CREATE_CMDID";
 	case WMI_NODE_REMOVE_CMDID:
 		return "WMI_NODE_REMOVE_CMDID";
 	case WMI_VAP_REMOVE_CMDID:
 		return "WMI_VAP_REMOVE_CMDID";
 	case WMI_VAP_CREATE_CMDID:
 		return "WMI_VAP_CREATE_CMDID";
 	case WMI_REG_READ_CMDID:
 		return "WMI_REG_READ_CMDID";
 	case WMI_REG_WRITE_CMDID:
 		return "WMI_REG_WRITE_CMDID";
 	case WMI_REG_RMW_CMDID:
 		return "WMI_REG_RMW_CMDID";
 	case WMI_RC_STATE_CHANGE_CMDID:
 		return "WMI_RC_STATE_CHANGE_CMDID";
 	case WMI_RC_RATE_UPDATE_CMDID:
 		return "WMI_RC_RATE_UPDATE_CMDID";
 	case WMI_TARGET_IC_UPDATE_CMDID:
 		return "WMI_TARGET_IC_UPDATE_CMDID";
 	case WMI_TX_AGGR_ENABLE_CMDID:
 		return "WMI_TX_AGGR_ENABLE_CMDID";
 	case WMI_TGT_DETACH_CMDID:
 		return "WMI_TGT_DETACH_CMDID";
 	case WMI_NODE_UPDATE_CMDID:
 		return "WMI_NODE_UPDATE_CMDID";
 	case WMI_INT_STATS_CMDID:
 		return "WMI_INT_STATS_CMDID";
 	case WMI_TX_STATS_CMDID:
 		return "WMI_TX_STATS_CMDID";
 	case WMI_RX_STATS_CMDID:
 		return "WMI_RX_STATS_CMDID";
 	case WMI_BITRATE_MASK_CMDID:
 		return "WMI_BITRATE_MASK_CMDID";
 	}

 	return "Bogus";
 }

 struct wmi *ath9k_init_wmi(struct ath9k_htc_priv *priv)
 {
 	struct wmi *wmi;

 	wmi = kzalloc(sizeof(struct wmi), GFP_KERNEL);
 	if (!wmi)
 		return NULL;

 	wmi->drv_priv = priv;
 	wmi->stopped = false;
 	skb_queue_head_init(&wmi->wmi_event_queue);
 	spin_lock_init(&wmi->wmi_lock);
 	spin_lock_init(&wmi->event_lock);
 	mutex_init(&wmi->op_mutex);
 	mutex_init(&wmi->multi_write_mutex);
 	mutex_init(&wmi->multi_rmw_mutex);
 	init_completion(&wmi->cmd_wait);
 	INIT_LIST_HEAD(&wmi->pending_tx_events);
 	tasklet_setup(&wmi->wmi_event_tasklet, ath9k_wmi_event_tasklet);

 	return wmi;
 }

 void ath9k_stop_wmi(struct ath9k_htc_priv *priv)
 {
 	struct wmi *wmi = priv->wmi;

 	mutex_lock(&wmi->op_mutex);
 	wmi->stopped = true;
 	mutex_unlock(&wmi->op_mutex);
 }

 void ath9k_destroy_wmi(struct ath9k_htc_priv *priv)
 {
 	kfree(priv->wmi);
 }

 void ath9k_wmi_event_drain(struct ath9k_htc_priv *priv)
 {
 	unsigned long flags;

 	tasklet_kill(&priv->wmi->wmi_event_tasklet);
 	spin_lock_irqsave(&priv->wmi->wmi_lock, flags);
 	__skb_queue_purge(&priv->wmi->wmi_event_queue);
 	spin_unlock_irqrestore(&priv->wmi->wmi_lock, flags);
 }

 void ath9k_wmi_event_tasklet(struct tasklet_struct *t)
 {
 	struct wmi *wmi = from_tasklet(wmi, t, wmi_event_tasklet);
 	struct ath9k_htc_priv *priv = wmi->drv_priv;
 	struct wmi_cmd_hdr *hdr;
 	void *wmi_event;
 	struct wmi_event_swba *swba;
 	struct sk_buff *skb = NULL;
 	unsigned long flags;
 	u16 cmd_id;

 	do {
 		spin_lock_irqsave(&wmi->wmi_lock, flags);
 		skb = __skb_dequeue(&wmi->wmi_event_queue);
 		if (!skb) {
 			spin_unlock_irqrestore(&wmi->wmi_lock, flags);
 			return;
 		}
 		spin_unlock_irqrestore(&wmi->wmi_lock, flags);

 		/* Check if ath9k_htc_probe_device() completed. */
 		if (!data_race(priv->initialized)) {
 			kfree_skb(skb);
 			continue;
 		}

 		hdr = (struct wmi_cmd_hdr *) skb->data;
 		cmd_id = be16_to_cpu(hdr->command_id);
 		wmi_event = skb_pull(skb, sizeof(struct wmi_cmd_hdr));

 		switch (cmd_id) {
 		case WMI_SWBA_EVENTID:
 			swba = wmi_event;
 			ath9k_htc_swba(priv, swba);
 			break;
 		case WMI_FATAL_EVENTID:
 			ieee80211_queue_work(wmi->drv_priv->hw,
 					     &wmi->drv_priv->fatal_work);
 			break;
 		case WMI_TXSTATUS_EVENTID:
 			spin_lock_bh(&priv->tx.tx_lock);
 			if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
 				spin_unlock_bh(&priv->tx.tx_lock);
 				break;
 			}
 			spin_unlock_bh(&priv->tx.tx_lock);

 			ath9k_htc_txstatus(priv, wmi_event);
 			break;
 		default:
 			break;
 		}

 		kfree_skb(skb);
 	} while (1);
 }

 void ath9k_fatal_work(struct work_struct *work)
 {
 	struct ath9k_htc_priv *priv = container_of(work, struct ath9k_htc_priv,
 						   fatal_work);
 	struct ath_common *common = ath9k_hw_common(priv->ah);

 	ath_dbg(common, FATAL, "FATAL Event received, resetting device\n");
 	ath9k_htc_reset(priv);
 }

 static void ath9k_wmi_rsp_callback(struct wmi *wmi, struct sk_buff *skb)
 {
 	skb_pull(skb, sizeof(struct wmi_cmd_hdr));

 	if (wmi->cmd_rsp_buf != NULL && wmi->cmd_rsp_len != 0)
 		memcpy(wmi->cmd_rsp_buf, skb->data, wmi->cmd_rsp_len);

 	complete(&wmi->cmd_wait);
 }

 static void ath9k_wmi_ctrl_rx(void *priv, struct sk_buff *skb,
 			      enum htc_endpoint_id epid)
 {
 	struct wmi *wmi = priv;
 	struct wmi_cmd_hdr *hdr;
 	unsigned long flags;
 	u16 cmd_id;

 	if (unlikely(wmi->stopped))
 		goto free_skb;

 	/* Validate the obtained SKB. */
 	if (unlikely(skb->len < sizeof(struct wmi_cmd_hdr)))
 		goto free_skb;

 	hdr = (struct wmi_cmd_hdr *) skb->data;
 	cmd_id = be16_to_cpu(hdr->command_id);

 	if (cmd_id & 0x1000) {
 		spin_lock_irqsave(&wmi->wmi_lock, flags);
 		__skb_queue_tail(&wmi->wmi_event_queue, skb);
 		spin_unlock_irqrestore(&wmi->wmi_lock, flags);
 		tasklet_schedule(&wmi->wmi_event_tasklet);
 		return;
 	}

 	/* Check if there has been a timeout. */
 	spin_lock_irqsave(&wmi->wmi_lock, flags);
 	if (be16_to_cpu(hdr->seq_no) != wmi->last_seq_id) {
 		spin_unlock_irqrestore(&wmi->wmi_lock, flags);
 		goto free_skb;
 	}

 	/* WMI command response */
 	ath9k_wmi_rsp_callback(wmi, skb);
 	spin_unlock_irqrestore(&wmi->wmi_lock, flags);

 free_skb:
 	kfree_skb(skb);
 }

 static void ath9k_wmi_ctrl_tx(void *priv, struct sk_buff *skb,
 			      enum htc_endpoint_id epid, bool txok)
 {
 	kfree_skb(skb);
 }

 int ath9k_wmi_connect(struct htc_target *htc, struct wmi *wmi,
 		      enum htc_endpoint_id *wmi_ctrl_epid)
 {
 	struct htc_service_connreq connect;
 	int ret;

 	wmi->htc = htc;

 	memset(&connect, 0, sizeof(connect));

 	connect.ep_callbacks.priv = wmi;
 	connect.ep_callbacks.tx = ath9k_wmi_ctrl_tx;
 	connect.ep_callbacks.rx = ath9k_wmi_ctrl_rx;
 	connect.service_id = WMI_CONTROL_SVC;

 	ret = htc_connect_service(htc, &connect, &wmi->ctrl_epid);
 	if (ret)
 		return ret;

 	*wmi_ctrl_epid = wmi->ctrl_epid;

 	return 0;
 }

 static int ath9k_wmi_cmd_issue(struct wmi *wmi,
 			       struct sk_buff *skb,
 			       enum wmi_cmd_id cmd, u16 len,
 			       u8 *rsp_buf, u32 rsp_len)
 {
 	struct wmi_cmd_hdr *hdr;
 	unsigned long flags;

 	hdr = skb_push(skb, sizeof(struct wmi_cmd_hdr));
 	hdr->command_id = cpu_to_be16(cmd);
 	hdr->seq_no = cpu_to_be16(++wmi->tx_seq_id);

 	spin_lock_irqsave(&wmi->wmi_lock, flags);

 	/* record the rsp buffer and length */
 	wmi->cmd_rsp_buf = rsp_buf;
 	wmi->cmd_rsp_len = rsp_len;

 	wmi->last_seq_id = wmi->tx_seq_id;
 	spin_unlock_irqrestore(&wmi->wmi_lock, flags);

 	return htc_send_epid(wmi->htc, skb, wmi->ctrl_epid);
 }

 int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id,
 		  u8 *cmd_buf, u32 cmd_len,
 		  u8 *rsp_buf, u32 rsp_len,
 		  u32 timeout)
 {
 	struct ath_hw *ah = wmi->drv_priv->ah;
 	struct ath_common *common = ath9k_hw_common(ah);
 	u16 headroom = sizeof(struct htc_frame_hdr) +
 		       sizeof(struct wmi_cmd_hdr);
 	unsigned long time_left, flags;
 	struct sk_buff *skb;
 	int ret = 0;

 	if (ah->ah_flags & AH_UNPLUGGED)
 		return 0;

 	skb = alloc_skb(headroom + cmd_len, GFP_ATOMIC);
 	if (!skb)
 		return -ENOMEM;

 	skb_reserve(skb, headroom);

 	if (cmd_len != 0 && cmd_buf != NULL) {
 		skb_put_data(skb, cmd_buf, cmd_len);
 	}

 	mutex_lock(&wmi->op_mutex);

 	/* check if wmi stopped flag is set */
 	if (unlikely(wmi->stopped)) {
 		ret = -EPROTO;
 		goto out;
 	}

 	ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len, rsp_buf, rsp_len);
 	if (ret)
 		goto out;

 	time_left = wait_for_completion_timeout(&wmi->cmd_wait, timeout);
 	if (!time_left) {
 		ath_dbg(common, WMI, "Timeout waiting for WMI command: %s\n",
 			wmi_cmd_to_name(cmd_id));
 		spin_lock_irqsave(&wmi->wmi_lock, flags);
 		wmi->last_seq_id = 0;
 		spin_unlock_irqrestore(&wmi->wmi_lock, flags);
 		mutex_unlock(&wmi->op_mutex);
 		return -ETIMEDOUT;
 	}

 	mutex_unlock(&wmi->op_mutex);

 	return 0;

 out:
 	ath_dbg(common, WMI, "WMI failure for: %s\n", wmi_cmd_to_name(cmd_id));
 	mutex_unlock(&wmi->op_mutex);
 	kfree_skb(skb);

 	return ret;
 }
	/*
	* Copyright (c) 2010-2011 Atheros Communications Inc.
	*
	* 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 "htc.h"

	static const char *wmi_cmd_to_name(enum wmi_cmd_id wmi_cmd)
	{
	switch (wmi_cmd) {
	case WMI_ECHO_CMDID:
	return "WMI_ECHO_CMDID";
	case WMI_ACCESS_MEMORY_CMDID:
	return "WMI_ACCESS_MEMORY_CMDID";
	case WMI_GET_FW_VERSION:
	return "WMI_GET_FW_VERSION";
	case WMI_DISABLE_INTR_CMDID:
	return "WMI_DISABLE_INTR_CMDID";
	case WMI_ENABLE_INTR_CMDID:
	return "WMI_ENABLE_INTR_CMDID";
	case WMI_ATH_INIT_CMDID:
	return "WMI_ATH_INIT_CMDID";
	case WMI_ABORT_TXQ_CMDID:
	return "WMI_ABORT_TXQ_CMDID";
	case WMI_STOP_TX_DMA_CMDID:
	return "WMI_STOP_TX_DMA_CMDID";
	case WMI_ABORT_TX_DMA_CMDID:
	return "WMI_ABORT_TX_DMA_CMDID";
	case WMI_DRAIN_TXQ_CMDID:
	return "WMI_DRAIN_TXQ_CMDID";
	case WMI_DRAIN_TXQ_ALL_CMDID:
	return "WMI_DRAIN_TXQ_ALL_CMDID";
	case WMI_START_RECV_CMDID:
	return "WMI_START_RECV_CMDID";
	case WMI_STOP_RECV_CMDID:
	return "WMI_STOP_RECV_CMDID";
	case WMI_FLUSH_RECV_CMDID:
	return "WMI_FLUSH_RECV_CMDID";
	case WMI_SET_MODE_CMDID:
	return "WMI_SET_MODE_CMDID";
	case WMI_NODE_CREATE_CMDID:
	return "WMI_NODE_CREATE_CMDID";
	case WMI_NODE_REMOVE_CMDID:
	return "WMI_NODE_REMOVE_CMDID";
	case WMI_VAP_REMOVE_CMDID:
	return "WMI_VAP_REMOVE_CMDID";
	case WMI_VAP_CREATE_CMDID:
	return "WMI_VAP_CREATE_CMDID";
	case WMI_REG_READ_CMDID:
	return "WMI_REG_READ_CMDID";
	case WMI_REG_WRITE_CMDID:
	return "WMI_REG_WRITE_CMDID";
	case WMI_REG_RMW_CMDID:
	return "WMI_REG_RMW_CMDID";
	case WMI_RC_STATE_CHANGE_CMDID:
	return "WMI_RC_STATE_CHANGE_CMDID";
	case WMI_RC_RATE_UPDATE_CMDID:
	return "WMI_RC_RATE_UPDATE_CMDID";
	case WMI_TARGET_IC_UPDATE_CMDID:
	return "WMI_TARGET_IC_UPDATE_CMDID";
	case WMI_TX_AGGR_ENABLE_CMDID:
	return "WMI_TX_AGGR_ENABLE_CMDID";
	case WMI_TGT_DETACH_CMDID:
	return "WMI_TGT_DETACH_CMDID";
	case WMI_NODE_UPDATE_CMDID:
	return "WMI_NODE_UPDATE_CMDID";
	case WMI_INT_STATS_CMDID:
	return "WMI_INT_STATS_CMDID";
	case WMI_TX_STATS_CMDID:
	return "WMI_TX_STATS_CMDID";
	case WMI_RX_STATS_CMDID:
	return "WMI_RX_STATS_CMDID";
	case WMI_BITRATE_MASK_CMDID:
	return "WMI_BITRATE_MASK_CMDID";
	}

	return "Bogus";
	}

	struct wmi ath9k_init_wmi(struct ath9k_htc_priv priv)
	{
	struct wmi *wmi;

	wmi = kzalloc(sizeof(struct wmi), GFP_KERNEL);
	if (!wmi)
	return NULL;

	wmi->drv_priv = priv;
	wmi->stopped = false;
	skb_queue_head_init(&wmi->wmi_event_queue);
	spin_lock_init(&wmi->wmi_lock);
	spin_lock_init(&wmi->event_lock);
	mutex_init(&wmi->op_mutex);
	mutex_init(&wmi->multi_write_mutex);
	mutex_init(&wmi->multi_rmw_mutex);
	init_completion(&wmi->cmd_wait);
	INIT_LIST_HEAD(&wmi->pending_tx_events);
	tasklet_setup(&wmi->wmi_event_tasklet, ath9k_wmi_event_tasklet);

	return wmi;
	}

	void ath9k_stop_wmi(struct ath9k_htc_priv *priv)
	{
	struct wmi *wmi = priv->wmi;

	mutex_lock(&wmi->op_mutex);
	wmi->stopped = true;
	mutex_unlock(&wmi->op_mutex);
	}

	void ath9k_destroy_wmi(struct ath9k_htc_priv *priv)
	{
	kfree(priv->wmi);
	}

	void ath9k_wmi_event_drain(struct ath9k_htc_priv *priv)
	{
	unsigned long flags;

	tasklet_kill(&priv->wmi->wmi_event_tasklet);
	spin_lock_irqsave(&priv->wmi->wmi_lock, flags);
	__skb_queue_purge(&priv->wmi->wmi_event_queue);
	spin_unlock_irqrestore(&priv->wmi->wmi_lock, flags);
	}

	void ath9k_wmi_event_tasklet(struct tasklet_struct *t)
	{
	struct wmi *wmi = from_tasklet(wmi, t, wmi_event_tasklet);
	struct ath9k_htc_priv *priv = wmi->drv_priv;
	struct wmi_cmd_hdr *hdr;
	void *wmi_event;
	struct wmi_event_swba *swba;
	struct sk_buff *skb = NULL;
	unsigned long flags;
	u16 cmd_id;

	do {
	spin_lock_irqsave(&wmi->wmi_lock, flags);
	skb = __skb_dequeue(&wmi->wmi_event_queue);
	if (!skb) {
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);
	return;
	}
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);

	/* Check if ath9k_htc_probe_device() completed. */
	if (!data_race(priv->initialized)) {
	kfree_skb(skb);
	continue;
	}

	hdr = (struct wmi_cmd_hdr *) skb->data;
	cmd_id = be16_to_cpu(hdr->command_id);
	wmi_event = skb_pull(skb, sizeof(struct wmi_cmd_hdr));

	switch (cmd_id) {
	case WMI_SWBA_EVENTID:
	swba = wmi_event;
	ath9k_htc_swba(priv, swba);
	break;
	case WMI_FATAL_EVENTID:
	ieee80211_queue_work(wmi->drv_priv->hw,
	&wmi->drv_priv->fatal_work);
	break;
	case WMI_TXSTATUS_EVENTID:
	spin_lock_bh(&priv->tx.tx_lock);
	if (priv->tx.flags & ATH9K_HTC_OP_TX_DRAIN) {
	spin_unlock_bh(&priv->tx.tx_lock);
	break;
	}
	spin_unlock_bh(&priv->tx.tx_lock);

	ath9k_htc_txstatus(priv, wmi_event);
	break;
	default:
	break;
	}

	kfree_skb(skb);
	} while (1);
	}

	void ath9k_fatal_work(struct work_struct *work)
	{
	struct ath9k_htc_priv *priv = container_of(work, struct ath9k_htc_priv,
	fatal_work);
	struct ath_common *common = ath9k_hw_common(priv->ah);

	ath_dbg(common, FATAL, "FATAL Event received, resetting device\n");
	ath9k_htc_reset(priv);
	}

	static void ath9k_wmi_rsp_callback(struct wmi wmi, struct sk_buff skb)
	{
	skb_pull(skb, sizeof(struct wmi_cmd_hdr));

	if (wmi->cmd_rsp_buf != NULL && wmi->cmd_rsp_len != 0)
	memcpy(wmi->cmd_rsp_buf, skb->data, wmi->cmd_rsp_len);

	complete(&wmi->cmd_wait);
	}

	static void ath9k_wmi_ctrl_rx(void priv, struct sk_buff skb,
	enum htc_endpoint_id epid)
	{
	struct wmi *wmi = priv;
	struct wmi_cmd_hdr *hdr;
	unsigned long flags;
	u16 cmd_id;

	if (unlikely(wmi->stopped))
	goto free_skb;

	/* Validate the obtained SKB. */
	if (unlikely(skb->len < sizeof(struct wmi_cmd_hdr)))
	goto free_skb;

	hdr = (struct wmi_cmd_hdr *) skb->data;
	cmd_id = be16_to_cpu(hdr->command_id);

	if (cmd_id & 0x1000) {
	spin_lock_irqsave(&wmi->wmi_lock, flags);
	__skb_queue_tail(&wmi->wmi_event_queue, skb);
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);
	tasklet_schedule(&wmi->wmi_event_tasklet);
	return;
	}

	/* Check if there has been a timeout. */
	spin_lock_irqsave(&wmi->wmi_lock, flags);
	if (be16_to_cpu(hdr->seq_no) != wmi->last_seq_id) {
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);
	goto free_skb;
	}

	/* WMI command response */
	ath9k_wmi_rsp_callback(wmi, skb);
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);

	free_skb:
	kfree_skb(skb);
	}

	static void ath9k_wmi_ctrl_tx(void priv, struct sk_buff skb,
	enum htc_endpoint_id epid, bool txok)
	{
	kfree_skb(skb);
	}

	int ath9k_wmi_connect(struct htc_target htc, struct wmi wmi,
	enum htc_endpoint_id *wmi_ctrl_epid)
	{
	struct htc_service_connreq connect;
	int ret;

	wmi->htc = htc;

	memset(&connect, 0, sizeof(connect));

	connect.ep_callbacks.priv = wmi;
	connect.ep_callbacks.tx = ath9k_wmi_ctrl_tx;
	connect.ep_callbacks.rx = ath9k_wmi_ctrl_rx;
	connect.service_id = WMI_CONTROL_SVC;

	ret = htc_connect_service(htc, &connect, &wmi->ctrl_epid);
	if (ret)
	return ret;

	*wmi_ctrl_epid = wmi->ctrl_epid;

	return 0;
	}

	static int ath9k_wmi_cmd_issue(struct wmi *wmi,
	struct sk_buff *skb,
	enum wmi_cmd_id cmd, u16 len,
	u8 *rsp_buf, u32 rsp_len)
	{
	struct wmi_cmd_hdr *hdr;
	unsigned long flags;

	hdr = skb_push(skb, sizeof(struct wmi_cmd_hdr));
	hdr->command_id = cpu_to_be16(cmd);
	hdr->seq_no = cpu_to_be16(++wmi->tx_seq_id);

	spin_lock_irqsave(&wmi->wmi_lock, flags);

	/* record the rsp buffer and length */
	wmi->cmd_rsp_buf = rsp_buf;
	wmi->cmd_rsp_len = rsp_len;

	wmi->last_seq_id = wmi->tx_seq_id;
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);

	return htc_send_epid(wmi->htc, skb, wmi->ctrl_epid);
	}

	int ath9k_wmi_cmd(struct wmi *wmi, enum wmi_cmd_id cmd_id,
	u8 *cmd_buf, u32 cmd_len,
	u8 *rsp_buf, u32 rsp_len,
	u32 timeout)
	{
	struct ath_hw *ah = wmi->drv_priv->ah;
	struct ath_common *common = ath9k_hw_common(ah);
	u16 headroom = sizeof(struct htc_frame_hdr) +
	sizeof(struct wmi_cmd_hdr);
	unsigned long time_left, flags;
	struct sk_buff *skb;
	int ret = 0;

	if (ah->ah_flags & AH_UNPLUGGED)
	return 0;

	skb = alloc_skb(headroom + cmd_len, GFP_ATOMIC);
	if (!skb)
	return -ENOMEM;

	skb_reserve(skb, headroom);

	if (cmd_len != 0 && cmd_buf != NULL) {
	skb_put_data(skb, cmd_buf, cmd_len);
	}

	mutex_lock(&wmi->op_mutex);

	/* check if wmi stopped flag is set */
	if (unlikely(wmi->stopped)) {
	ret = -EPROTO;
	goto out;
	}

	ret = ath9k_wmi_cmd_issue(wmi, skb, cmd_id, cmd_len, rsp_buf, rsp_len);
	if (ret)
	goto out;

	time_left = wait_for_completion_timeout(&wmi->cmd_wait, timeout);
	if (!time_left) {
	ath_dbg(common, WMI, "Timeout waiting for WMI command: %s\n",
	wmi_cmd_to_name(cmd_id));
	spin_lock_irqsave(&wmi->wmi_lock, flags);
	wmi->last_seq_id = 0;
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);
	mutex_unlock(&wmi->op_mutex);
	return -ETIMEDOUT;
	}

	mutex_unlock(&wmi->op_mutex);

	return 0;

	out:
	ath_dbg(common, WMI, "WMI failure for: %s\n", wmi_cmd_to_name(cmd_id));
	mutex_unlock(&wmi->op_mutex);
	kfree_skb(skb);

	return ret;
	}