/*
   * 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_init(&wmi->wmi_event_tasklet, ath9k_wmi_event_tasklet,
  		     (unsigned long)wmi);
  
  	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_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(unsigned long data)
  {
  	struct wmi *wmi = (struct wmi *)data;
  	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);
  
  		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 = (struct wmi_event_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
  ");
  	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 = (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);
  		__skb_queue_tail(&wmi->wmi_event_queue, skb);
  		spin_unlock(&wmi->wmi_lock);
  		tasklet_schedule(&wmi->wmi_event_tasklet);
  		return;
  	}
  
  	/* Check if there has been a timeout. */
  	spin_lock(&wmi->wmi_lock);
  	if (be16_to_cpu(hdr->seq_no) != wmi->last_seq_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;
  	unsigned long flags;
  
  	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);
  
  	spin_lock_irqsave(&wmi->wmi_lock, flags);
  	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);
  	struct sk_buff *skb;
  	u8 *data;
  	unsigned long time_left;
  	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) {
  		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;
  
  	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_dbg(common, WMI, "Timeout waiting for WMI command: %s
  ",
  			wmi_cmd_to_name(cmd_id));
  		mutex_unlock(&wmi->op_mutex);
  		return -ETIMEDOUT;
  	}
  
  	mutex_unlock(&wmi->op_mutex);
  
  	return 0;
  
  out:
  	ath_dbg(common, WMI, "WMI failure for: %s
  ", wmi_cmd_to_name(cmd_id));
  	mutex_unlock(&wmi->op_mutex);
  	kfree_skb(skb);
  
  	return ret;
  }