/*
 * 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_obj(struct wmi);
        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;
}