/*
 * 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.
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include "htc.h"

static int htc_issue_send(struct htc_target *target, struct sk_buff* skb,
                          u16 len, u8 flags, u8 epid)

{
        struct htc_frame_hdr *hdr;
        struct htc_endpoint *endpoint = &target->endpoint[epid];
        int status;

        hdr = skb_push(skb, sizeof(struct htc_frame_hdr));
        hdr->endpoint_id = epid;
        hdr->flags = flags;
        hdr->payload_len = cpu_to_be16(len);
        memset(hdr->control, 0, sizeof(hdr->control));

        status = target->hif->send(target->hif_dev, endpoint->ul_pipeid, skb);

        return status;
}

static struct htc_endpoint *get_next_avail_ep(struct htc_endpoint *endpoint)
{
        enum htc_endpoint_id avail_epid;

        for (avail_epid = (ENDPOINT_MAX - 1); avail_epid > ENDPOINT0; avail_epid--)
                if (endpoint[avail_epid].service_id == 0)
                        return &endpoint[avail_epid];
        return NULL;
}

static u8 service_to_ulpipe(u16 service_id)
{
        switch (service_id) {
        case WMI_CONTROL_SVC:
                return 4;
        case WMI_BEACON_SVC:
        case WMI_CAB_SVC:
        case WMI_UAPSD_SVC:
        case WMI_MGMT_SVC:
        case WMI_DATA_VO_SVC:
        case WMI_DATA_VI_SVC:
        case WMI_DATA_BE_SVC:
        case WMI_DATA_BK_SVC:
                return 1;
        default:
                return 0;
        }
}

static u8 service_to_dlpipe(u16 service_id)
{
        switch (service_id) {
        case WMI_CONTROL_SVC:
                return 3;
        case WMI_BEACON_SVC:
        case WMI_CAB_SVC:
        case WMI_UAPSD_SVC:
        case WMI_MGMT_SVC:
        case WMI_DATA_VO_SVC:
        case WMI_DATA_VI_SVC:
        case WMI_DATA_BE_SVC:
        case WMI_DATA_BK_SVC:
                return 2;
        default:
                return 0;
        }
}

static void htc_process_target_rdy(struct htc_target *target,
                                   void *buf)
{
        struct htc_endpoint *endpoint;
        struct htc_ready_msg *htc_ready_msg = buf;

        target->credit_size = be16_to_cpu(htc_ready_msg->credit_size);

        endpoint = &target->endpoint[ENDPOINT0];
        endpoint->service_id = HTC_CTRL_RSVD_SVC;
        endpoint->max_msglen = HTC_MAX_CONTROL_MESSAGE_LENGTH;
        atomic_inc(&target->tgt_ready);
        complete(&target->target_wait);
}

static void htc_process_conn_rsp(struct htc_target *target,
                                 struct htc_frame_hdr *htc_hdr)
{
        struct htc_conn_svc_rspmsg *svc_rspmsg;
        struct htc_endpoint *endpoint, *tmp_endpoint = NULL;
        u16 service_id;
        u16 max_msglen;
        enum htc_endpoint_id epid, tepid;

        svc_rspmsg = (struct htc_conn_svc_rspmsg *)
                ((void *) htc_hdr + sizeof(struct htc_frame_hdr));

        if (svc_rspmsg->status == HTC_SERVICE_SUCCESS) {
                epid = svc_rspmsg->endpoint_id;

                /* Check that the received epid for the endpoint to attach
                 * a new service is valid. ENDPOINT0 can't be used here as it
                 * is already reserved for HTC_CTRL_RSVD_SVC service and thus
                 * should not be modified.
                 */
                if (epid <= ENDPOINT0 || epid >= ENDPOINT_MAX)
                        return;

                service_id = be16_to_cpu(svc_rspmsg->service_id);
                max_msglen = be16_to_cpu(svc_rspmsg->max_msg_len);
                endpoint = &target->endpoint[epid];

                for (tepid = (ENDPOINT_MAX - 1); tepid > ENDPOINT0; tepid--) {
                        tmp_endpoint = &target->endpoint[tepid];
                        if (tmp_endpoint->service_id == service_id) {
                                tmp_endpoint->service_id = 0;
                                break;
                        }
                }

                if (tepid == ENDPOINT0)
                        return;

                endpoint->service_id = service_id;
                endpoint->max_txqdepth = tmp_endpoint->max_txqdepth;
                endpoint->ep_callbacks = tmp_endpoint->ep_callbacks;
                endpoint->ul_pipeid = tmp_endpoint->ul_pipeid;
                endpoint->dl_pipeid = tmp_endpoint->dl_pipeid;
                endpoint->max_msglen = max_msglen;
                target->conn_rsp_epid = epid;
                complete(&target->cmd_wait);
        } else {
                target->conn_rsp_epid = ENDPOINT_UNUSED;
        }
}

static int htc_config_pipe_credits(struct htc_target *target)
{
        struct sk_buff *skb;
        struct htc_config_pipe_msg *cp_msg;
        int ret;
        unsigned long time_left;

        skb = alloc_skb(50 + sizeof(struct htc_frame_hdr), GFP_ATOMIC);
        if (!skb) {
                dev_err(target->dev, "failed to allocate send buffer\n");
                return -ENOMEM;
        }
        skb_reserve(skb, sizeof(struct htc_frame_hdr));

        cp_msg = skb_put(skb, sizeof(struct htc_config_pipe_msg));

        cp_msg->message_id = cpu_to_be16(HTC_MSG_CONFIG_PIPE_ID);
        cp_msg->pipe_id = USB_WLAN_TX_PIPE;
        cp_msg->credits = target->credits;

        target->htc_flags |= HTC_OP_CONFIG_PIPE_CREDITS;

        ret = htc_issue_send(target, skb, skb->len, 0, ENDPOINT0);
        if (ret)
                goto err;

        time_left = wait_for_completion_timeout(&target->cmd_wait, HZ);
        if (!time_left) {
                dev_err(target->dev, "HTC credit config timeout\n");
                return -ETIMEDOUT;
        }

        return 0;
err:
        kfree_skb(skb);
        return -EINVAL;
}

static int htc_setup_complete(struct htc_target *target)
{
        struct sk_buff *skb;
        struct htc_comp_msg *comp_msg;
        int ret = 0;
        unsigned long time_left;

        skb = alloc_skb(50 + sizeof(struct htc_frame_hdr), GFP_ATOMIC);
        if (!skb) {
                dev_err(target->dev, "failed to allocate send buffer\n");
                return -ENOMEM;
        }
        skb_reserve(skb, sizeof(struct htc_frame_hdr));

        comp_msg = skb_put(skb, sizeof(struct htc_comp_msg));
        comp_msg->msg_id = cpu_to_be16(HTC_MSG_SETUP_COMPLETE_ID);

        target->htc_flags |= HTC_OP_START_WAIT;

        ret = htc_issue_send(target, skb, skb->len, 0, ENDPOINT0);
        if (ret)
                goto err;

        time_left = wait_for_completion_timeout(&target->cmd_wait, HZ);
        if (!time_left) {
                dev_err(target->dev, "HTC start timeout\n");
                return -ETIMEDOUT;
        }

        return 0;

err:
        kfree_skb(skb);
        return -EINVAL;
}

/* HTC APIs */

int htc_init(struct htc_target *target)
{
        int ret;

        ret = htc_config_pipe_credits(target);
        if (ret)
                return ret;

        return htc_setup_complete(target);
}

int htc_connect_service(struct htc_target *target,
                     struct htc_service_connreq *service_connreq,
                     enum htc_endpoint_id *conn_rsp_epid)
{
        struct sk_buff *skb;
        struct htc_endpoint *endpoint;
        struct htc_conn_svc_msg *conn_msg;
        int ret;
        unsigned long time_left;

        /* Find an available endpoint */
        endpoint = get_next_avail_ep(target->endpoint);
        if (!endpoint) {
                dev_err(target->dev, "Endpoint is not available for service %d\n",
                        service_connreq->service_id);
                return -EINVAL;
        }

        endpoint->service_id = service_connreq->service_id;
        endpoint->max_txqdepth = service_connreq->max_send_qdepth;
        endpoint->ul_pipeid = service_to_ulpipe(service_connreq->service_id);
        endpoint->dl_pipeid = service_to_dlpipe(service_connreq->service_id);
        endpoint->ep_callbacks = service_connreq->ep_callbacks;

        skb = alloc_skb(sizeof(struct htc_conn_svc_msg) +
                            sizeof(struct htc_frame_hdr), GFP_ATOMIC);
        if (!skb) {
                dev_err(target->dev, "Failed to allocate buf to send"
                        "service connect req\n");
                return -ENOMEM;
        }

        skb_reserve(skb, sizeof(struct htc_frame_hdr));

        conn_msg = skb_put(skb, sizeof(struct htc_conn_svc_msg));
        conn_msg->service_id = cpu_to_be16(service_connreq->service_id);
        conn_msg->msg_id = cpu_to_be16(HTC_MSG_CONNECT_SERVICE_ID);
        conn_msg->con_flags = cpu_to_be16(service_connreq->con_flags);
        conn_msg->dl_pipeid = endpoint->dl_pipeid;
        conn_msg->ul_pipeid = endpoint->ul_pipeid;

        /* To prevent infoleak */
        conn_msg->svc_meta_len = 0;
        conn_msg->pad = 0;

        ret = htc_issue_send(target, skb, skb->len, 0, ENDPOINT0);
        if (ret)
                goto err;

        time_left = wait_for_completion_timeout(&target->cmd_wait, HZ);
        if (!time_left) {
                dev_err(target->dev, "Service connection timeout for: %d\n",
                        service_connreq->service_id);
                return -ETIMEDOUT;
        }

        if (target->conn_rsp_epid < 0 || target->conn_rsp_epid >= ENDPOINT_MAX)
                return -EINVAL;

        *conn_rsp_epid = target->conn_rsp_epid;
        return 0;
err:
        kfree_skb(skb);
        return ret;
}

int htc_send(struct htc_target *target, struct sk_buff *skb)
{
        struct ath9k_htc_tx_ctl *tx_ctl;

        tx_ctl = HTC_SKB_CB(skb);
        return htc_issue_send(target, skb, skb->len, 0, tx_ctl->epid);
}

int htc_send_epid(struct htc_target *target, struct sk_buff *skb,
                  enum htc_endpoint_id epid)
{
        return htc_issue_send(target, skb, skb->len, 0, epid);
}

void htc_stop(struct htc_target *target)
{
        target->hif->stop(target->hif_dev);
}

void htc_start(struct htc_target *target)
{
        target->hif->start(target->hif_dev);
}

void htc_sta_drain(struct htc_target *target, u8 idx)
{
        target->hif->sta_drain(target->hif_dev, idx);
}

void ath9k_htc_txcompletion_cb(struct htc_target *htc_handle,
                               struct sk_buff *skb, bool txok)
{
        struct htc_endpoint *endpoint;
        struct htc_frame_hdr *htc_hdr = NULL;

        if (htc_handle->htc_flags & HTC_OP_CONFIG_PIPE_CREDITS) {
                complete(&htc_handle->cmd_wait);
                htc_handle->htc_flags &= ~HTC_OP_CONFIG_PIPE_CREDITS;
                goto ret;
        }

        if (htc_handle->htc_flags & HTC_OP_START_WAIT) {
                complete(&htc_handle->cmd_wait);
                htc_handle->htc_flags &= ~HTC_OP_START_WAIT;
                goto ret;
        }

        if (skb) {
                htc_hdr = (struct htc_frame_hdr *) skb->data;
                if (htc_hdr->endpoint_id >= ARRAY_SIZE(htc_handle->endpoint))
                        goto ret;
                endpoint = &htc_handle->endpoint[htc_hdr->endpoint_id];
                skb_pull(skb, sizeof(struct htc_frame_hdr));

                if (endpoint->ep_callbacks.tx) {
                        endpoint->ep_callbacks.tx(endpoint->ep_callbacks.priv,
                                                  skb, htc_hdr->endpoint_id,
                                                  txok);
                } else {
                        kfree_skb(skb);
                }
        }

        return;
ret:
        kfree_skb(skb);
}

static void ath9k_htc_fw_panic_report(struct htc_target *htc_handle,
                                      struct sk_buff *skb, u32 len)
{
        uint32_t *pattern = (uint32_t *)skb->data;

        if (*pattern == 0x33221199 && len >= sizeof(struct htc_panic_bad_vaddr)) {
                struct htc_panic_bad_vaddr *htc_panic;
                htc_panic = (struct htc_panic_bad_vaddr *) skb->data;
                dev_err(htc_handle->dev, "ath: firmware panic! "
                        "exccause: 0x%08x; pc: 0x%08x; badvaddr: 0x%08x.\n",
                        htc_panic->exccause, htc_panic->pc,
                        htc_panic->badvaddr);
                return;
        }
        if (*pattern == 0x33221299) {
                struct htc_panic_bad_epid *htc_panic;
                htc_panic = (struct htc_panic_bad_epid *) skb->data;
                dev_err(htc_handle->dev, "ath: firmware panic! "
                        "bad epid: 0x%08x\n", htc_panic->epid);
                return;
        }
        dev_err(htc_handle->dev, "ath: unknown panic pattern!\n");
}

/*
 * HTC Messages are handled directly here and the obtained SKB
 * is freed.
 *
 * Service messages (Data, WMI) are passed to the corresponding
 * endpoint RX handlers, which have to free the SKB.
 */
void ath9k_htc_rx_msg(struct htc_target *htc_handle,
                      struct sk_buff *skb, u32 len, u8 pipe_id)
{
        struct htc_frame_hdr *htc_hdr;
        enum htc_endpoint_id epid;
        struct htc_endpoint *endpoint;
        __be16 *msg_id;

        if (!htc_handle || !skb)
                return;

        /* A valid message requires len >= 8.
         *
         *   sizeof(struct htc_frame_hdr) == 8
         *   sizeof(struct htc_ready_msg) == 8
         *   sizeof(struct htc_panic_bad_vaddr) == 16
         *   sizeof(struct htc_panic_bad_epid) == 8
         */
        if (unlikely(len < sizeof(struct htc_frame_hdr)))
                goto invalid;
        htc_hdr = (struct htc_frame_hdr *) skb->data;
        epid = htc_hdr->endpoint_id;

        if (epid == 0x99) {
                ath9k_htc_fw_panic_report(htc_handle, skb, len);
                kfree_skb(skb);
                return;
        }

        if (epid < 0 || epid >= ENDPOINT_MAX) {
invalid:
                if (pipe_id != USB_REG_IN_PIPE)
                        dev_kfree_skb_any(skb);
                else
                        kfree_skb(skb);
                return;
        }

        if (epid == ENDPOINT0) {

                /* Handle trailer */
                if (htc_hdr->flags & HTC_FLAGS_RECV_TRAILER) {
                        if (be32_to_cpu(*(__be32 *) skb->data) == 0x00C60000) {
                                /* Move past the Watchdog pattern */
                                htc_hdr = (struct htc_frame_hdr *)(skb->data + 4);
                                len -= 4;
                        }
                }

                /* Get the message ID */
                if (unlikely(len < sizeof(struct htc_frame_hdr) + sizeof(__be16)))
                        goto invalid;
                msg_id = (__be16 *) ((void *) htc_hdr +
                                     sizeof(struct htc_frame_hdr));

                /* Now process HTC messages */
                switch (be16_to_cpu(*msg_id)) {
                case HTC_MSG_READY_ID:
                        if (unlikely(len < sizeof(struct htc_ready_msg)))
                                goto invalid;
                        htc_process_target_rdy(htc_handle, htc_hdr);
                        break;
                case HTC_MSG_CONNECT_SERVICE_RESPONSE_ID:
                        if (unlikely(len < sizeof(struct htc_frame_hdr) +
                                     sizeof(struct htc_conn_svc_rspmsg)))
                                goto invalid;
                        htc_process_conn_rsp(htc_handle, htc_hdr);
                        break;
                default:
                        break;
                }

                kfree_skb(skb);

        } else {
                if (htc_hdr->flags & HTC_FLAGS_RECV_TRAILER)
                        skb_trim(skb, len - htc_hdr->control[0]);

                skb_pull(skb, sizeof(struct htc_frame_hdr));

                endpoint = &htc_handle->endpoint[epid];
                if (endpoint->ep_callbacks.rx)
                        endpoint->ep_callbacks.rx(endpoint->ep_callbacks.priv,
                                                  skb, epid);
                else
                        goto invalid;
        }
}

struct htc_target *ath9k_htc_hw_alloc(void *hif_handle,
                                      struct ath9k_htc_hif *hif,
                                      struct device *dev)
{
        struct htc_endpoint *endpoint;
        struct htc_target *target;

        target = kzalloc_obj(struct htc_target);
        if (!target)
                return NULL;

        init_completion(&target->target_wait);
        init_completion(&target->cmd_wait);

        target->hif = hif;
        target->hif_dev = hif_handle;
        target->dev = dev;

        /* Assign control endpoint pipe IDs */
        endpoint = &target->endpoint[ENDPOINT0];
        endpoint->ul_pipeid = hif->control_ul_pipe;
        endpoint->dl_pipeid = hif->control_dl_pipe;

        atomic_set(&target->tgt_ready, 0);

        return target;
}

void ath9k_htc_hw_free(struct htc_target *htc)
{
        kfree(htc);
}

int ath9k_htc_hw_init(struct htc_target *target,
                      struct device *dev, u16 devid,
                      char *product, u32 drv_info)
{
        if (ath9k_htc_probe_device(target, dev, devid, product, drv_info)) {
                pr_err("Failed to initialize the device\n");
                return -ENODEV;
        }

        return 0;
}

void ath9k_htc_hw_deinit(struct htc_target *target, bool hot_unplug)
{
        if (target)
                ath9k_htc_disconnect_device(target, hot_unplug);
}