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

 /*
  * Copyright (c) 2010 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_DISABLE_INTR_CMDID:
 		return "WMI_DISABLE_INTR_CMDID";
 	case WMI_ENABLE_INTR_CMDID:
 		return "WMI_ENABLE_INTR_CMDID";
 	case WMI_RX_LINK_CMDID:
 		return "WMI_RX_LINK_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_STOP_DMA_RECV_CMDID:
 		return "WMI_STOP_DMA_RECV_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_RESET_CMDID:
 		return "WMI_RESET_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_BEACON_UPDATE_CMDID:
 		return "WMI_BEACON_UPDATE_CMDID";
 	case WMI_REG_READ_CMDID:
 		return "WMI_REG_READ_CMDID";
 	case WMI_REG_WRITE_CMDID:
 		return "WMI_REG_WRITE_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_DEBUG_INFO_CMDID:
 		return "WMI_DEBUG_INFO_CMDID";
 	case WMI_HOST_ATTACH:
 		return "WMI_HOST_ATTACH";
 	case WMI_TARGET_IC_UPDATE_CMDID:
 		return "WMI_TARGET_IC_UPDATE_CMDID";
 	case WMI_TGT_STATS_CMDID:
 		return "WMI_TGT_STATS_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_TGT_TXQ_ENABLE_CMDID:
 		return "WMI_TGT_TXQ_ENABLE_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;
 	mutex_init(&wmi->op_mutex);
 	mutex_init(&wmi->multi_write_mutex);
 	init_completion(&wmi->cmd_wait);

 	return wmi;
 }

 void ath9k_deinit_wmi(struct ath9k_htc_priv *priv)
 {
 	struct wmi *wmi = priv->wmi;

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

 	kfree(priv->wmi);
 }

 void ath9k_wmi_tasklet(unsigned long data)
 {
 	struct ath9k_htc_priv *priv = (struct ath9k_htc_priv *)data;
 	struct ath_common *common = ath9k_hw_common(priv->ah);
 	struct wmi_cmd_hdr *hdr;
 	struct wmi_swba *swba_hdr;
 	enum wmi_event_id event;
 	struct sk_buff *skb;
 	void *wmi_event;
 	unsigned long flags;
 #ifdef CONFIG_ATH9K_HTC_DEBUGFS
 	__be32 txrate;
 #endif

 	spin_lock_irqsave(&priv->wmi->wmi_lock, flags);
 	skb = priv->wmi->wmi_skb;
 	spin_unlock_irqrestore(&priv->wmi->wmi_lock, flags);

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

 	ath_print(common, ATH_DBG_WMI,
 		  "WMI Event: 0x%x\n", event);

 	switch (event) {
 	case WMI_TGT_RDY_EVENTID:
 		break;
 	case WMI_SWBA_EVENTID:
 		swba_hdr = (struct wmi_swba *) wmi_event;
 		ath9k_htc_swba(priv, swba_hdr->beacon_pending);
 		break;
 	case WMI_FATAL_EVENTID:
 		break;
 	case WMI_TXTO_EVENTID:
 		break;
 	case WMI_BMISS_EVENTID:
 		break;
 	case WMI_WLAN_TXCOMP_EVENTID:
 		break;
 	case WMI_DELBA_EVENTID:
 		break;
 	case WMI_TXRATE_EVENTID:
 #ifdef CONFIG_ATH9K_HTC_DEBUGFS
 		txrate = ((struct wmi_event_txrate *)wmi_event)->txrate;
 		priv->debug.txrate = be32_to_cpu(txrate);
 #endif
 		break;
 	default:
 		break;
 	}

 	kfree_skb(skb);
 }

 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 = (struct wmi *) priv;
 	struct wmi_cmd_hdr *hdr;
 	u16 cmd_id;

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

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

 	if (cmd_id & 0x1000) {
 		spin_lock(&wmi->wmi_lock);
 		wmi->wmi_skb = skb;
 		spin_unlock(&wmi->wmi_lock);
 		tasklet_schedule(&wmi->drv_priv->wmi_tasklet);
 		return;
 	}

 	/* Check if there has been a timeout. */
 	spin_lock(&wmi->wmi_lock);
 	if (cmd_id != wmi->last_cmd_id) {
 		spin_unlock(&wmi->wmi_lock);
 		goto free_skb;
 	}
 	spin_unlock(&wmi->wmi_lock);

 	/* WMI command response */
 	ath9k_wmi_rsp_callback(wmi, skb);

 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)
 {
 	struct wmi_cmd_hdr *hdr;

 	hdr = (struct wmi_cmd_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);

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

 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);
 	struct sk_buff *skb;
 	u8 *data;
 	int time_left, ret = 0;
 	unsigned long flags;

 	if (wmi->drv_priv->op_flags & OP_UNPLUGGED)
 		return 0;

 	if (!wmi)
 		return -EINVAL;

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

 	skb_reserve(skb, headroom);

 	if (cmd_len != 0 && cmd_buf != NULL) {
 		data = (u8 *) skb_put(skb, cmd_len);
 		memcpy(data, cmd_buf, cmd_len);
 	}

 	mutex_lock(&wmi->op_mutex);

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

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

 	spin_lock_irqsave(&wmi->wmi_lock, flags);
 	wmi->last_cmd_id = cmd_id;
 	spin_unlock_irqrestore(&wmi->wmi_lock, flags);

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

 	time_left = wait_for_completion_timeout(&wmi->cmd_wait, timeout);
 	if (!time_left) {
 		ath_print(common, ATH_DBG_WMI,
 			  "Timeout waiting for WMI command: %s\n",
 			  wmi_cmd_to_name(cmd_id));
 		mutex_unlock(&wmi->op_mutex);
 		return -ETIMEDOUT;
 	}

 	mutex_unlock(&wmi->op_mutex);

 	return 0;

 out:
 	ath_print(common, ATH_DBG_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 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_DISABLE_INTR_CMDID:
	return "WMI_DISABLE_INTR_CMDID";
	case WMI_ENABLE_INTR_CMDID:
	return "WMI_ENABLE_INTR_CMDID";
	case WMI_RX_LINK_CMDID:
	return "WMI_RX_LINK_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_STOP_DMA_RECV_CMDID:
	return "WMI_STOP_DMA_RECV_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_RESET_CMDID:
	return "WMI_RESET_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_BEACON_UPDATE_CMDID:
	return "WMI_BEACON_UPDATE_CMDID";
	case WMI_REG_READ_CMDID:
	return "WMI_REG_READ_CMDID";
	case WMI_REG_WRITE_CMDID:
	return "WMI_REG_WRITE_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_DEBUG_INFO_CMDID:
	return "WMI_DEBUG_INFO_CMDID";
	case WMI_HOST_ATTACH:
	return "WMI_HOST_ATTACH";
	case WMI_TARGET_IC_UPDATE_CMDID:
	return "WMI_TARGET_IC_UPDATE_CMDID";
	case WMI_TGT_STATS_CMDID:
	return "WMI_TGT_STATS_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_TGT_TXQ_ENABLE_CMDID:
	return "WMI_TGT_TXQ_ENABLE_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;
	mutex_init(&wmi->op_mutex);
	mutex_init(&wmi->multi_write_mutex);
	init_completion(&wmi->cmd_wait);

	return wmi;
	}

	void ath9k_deinit_wmi(struct ath9k_htc_priv *priv)
	{
	struct wmi *wmi = priv->wmi;

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

	kfree(priv->wmi);
	}

	void ath9k_wmi_tasklet(unsigned long data)
	{
	struct ath9k_htc_priv priv = (struct ath9k_htc_priv )data;
	struct ath_common *common = ath9k_hw_common(priv->ah);
	struct wmi_cmd_hdr *hdr;
	struct wmi_swba *swba_hdr;
	enum wmi_event_id event;
	struct sk_buff *skb;
	void *wmi_event;
	unsigned long flags;
	#ifdef CONFIG_ATH9K_HTC_DEBUGFS
	__be32 txrate;
	#endif

	spin_lock_irqsave(&priv->wmi->wmi_lock, flags);
	skb = priv->wmi->wmi_skb;
	spin_unlock_irqrestore(&priv->wmi->wmi_lock, flags);

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

	ath_print(common, ATH_DBG_WMI,
	"WMI Event: 0x%x\n", event);

	switch (event) {
	case WMI_TGT_RDY_EVENTID:
	break;
	case WMI_SWBA_EVENTID:
	swba_hdr = (struct wmi_swba *) wmi_event;
	ath9k_htc_swba(priv, swba_hdr->beacon_pending);
	break;
	case WMI_FATAL_EVENTID:
	break;
	case WMI_TXTO_EVENTID:
	break;
	case WMI_BMISS_EVENTID:
	break;
	case WMI_WLAN_TXCOMP_EVENTID:
	break;
	case WMI_DELBA_EVENTID:
	break;
	case WMI_TXRATE_EVENTID:
	#ifdef CONFIG_ATH9K_HTC_DEBUGFS
	txrate = ((struct wmi_event_txrate *)wmi_event)->txrate;
	priv->debug.txrate = be32_to_cpu(txrate);
	#endif
	break;
	default:
	break;
	}

	kfree_skb(skb);
	}

	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 = (struct wmi ) priv;
	struct wmi_cmd_hdr *hdr;
	u16 cmd_id;

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

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

	if (cmd_id & 0x1000) {
	spin_lock(&wmi->wmi_lock);
	wmi->wmi_skb = skb;
	spin_unlock(&wmi->wmi_lock);
	tasklet_schedule(&wmi->drv_priv->wmi_tasklet);
	return;
	}

	/* Check if there has been a timeout. */
	spin_lock(&wmi->wmi_lock);
	if (cmd_id != wmi->last_cmd_id) {
	spin_unlock(&wmi->wmi_lock);
	goto free_skb;
	}
	spin_unlock(&wmi->wmi_lock);

	/* WMI command response */
	ath9k_wmi_rsp_callback(wmi, skb);

	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)
	{
	struct wmi_cmd_hdr *hdr;

	hdr = (struct wmi_cmd_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);

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

	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);
	struct sk_buff *skb;
	u8 *data;
	int time_left, ret = 0;
	unsigned long flags;

	if (wmi->drv_priv->op_flags & OP_UNPLUGGED)
	return 0;

	if (!wmi)
	return -EINVAL;

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

	skb_reserve(skb, headroom);

	if (cmd_len != 0 && cmd_buf != NULL) {
	data = (u8 *) skb_put(skb, cmd_len);
	memcpy(data, cmd_buf, cmd_len);
	}

	mutex_lock(&wmi->op_mutex);

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

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

	spin_lock_irqsave(&wmi->wmi_lock, flags);
	wmi->last_cmd_id = cmd_id;
	spin_unlock_irqrestore(&wmi->wmi_lock, flags);

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

	time_left = wait_for_completion_timeout(&wmi->cmd_wait, timeout);
	if (!time_left) {
	ath_print(common, ATH_DBG_WMI,
	"Timeout waiting for WMI command: %s\n",
	wmi_cmd_to_name(cmd_id));
	mutex_unlock(&wmi->op_mutex);
	return -ETIMEDOUT;
	}

	mutex_unlock(&wmi->op_mutex);

	return 0;

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

	return ret;
	}