// SPDX-License-Identifier: BSD-3-Clause-Clear
/*
 * Copyright (c) 2018-2021 The Linux Foundation. All rights reserved.
 * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
 */
#include <linux/skbuff.h>
#include <linux/ctype.h>

#include "debug.h"
#include "hif.h"

struct sk_buff *ath12k_htc_alloc_skb(struct ath12k_base *ab, int size)
{
        struct sk_buff *skb;

        skb = dev_alloc_skb(size + sizeof(struct ath12k_htc_hdr));
        if (!skb)
                return NULL;

        skb_reserve(skb, sizeof(struct ath12k_htc_hdr));

        /* FW/HTC requires 4-byte aligned streams */
        if (!IS_ALIGNED((unsigned long)skb->data, 4))
                ath12k_warn(ab, "Unaligned HTC tx skb\n");

        return skb;
}

static void ath12k_htc_control_tx_complete(struct ath12k_base *ab,
                                           struct sk_buff *skb)
{
        kfree_skb(skb);
}

static struct sk_buff *ath12k_htc_build_tx_ctrl_skb(void)
{
        struct sk_buff *skb;
        struct ath12k_skb_cb *skb_cb;

        skb = dev_alloc_skb(ATH12K_HTC_CONTROL_BUFFER_SIZE);
        if (!skb)
                return NULL;

        skb_reserve(skb, sizeof(struct ath12k_htc_hdr));
        WARN_ON_ONCE(!IS_ALIGNED((unsigned long)skb->data, 4));

        skb_cb = ATH12K_SKB_CB(skb);
        memset(skb_cb, 0, sizeof(*skb_cb));

        return skb;
}

static void ath12k_htc_prepare_tx_skb(struct ath12k_htc_ep *ep,
                                      struct sk_buff *skb)
{
        struct ath12k_htc_hdr *hdr;

        hdr = (struct ath12k_htc_hdr *)skb->data;

        memset(hdr, 0, sizeof(*hdr));
        hdr->htc_info = le32_encode_bits(ep->eid, HTC_HDR_ENDPOINTID) |
                        le32_encode_bits((skb->len - sizeof(*hdr)),
                                         HTC_HDR_PAYLOADLEN);

        if (ep->tx_credit_flow_enabled)
                hdr->htc_info |= le32_encode_bits(ATH12K_HTC_FLAG_NEED_CREDIT_UPDATE,
                                                  HTC_HDR_FLAGS);

        spin_lock_bh(&ep->htc->tx_lock);
        hdr->ctrl_info = le32_encode_bits(ep->seq_no++, HTC_HDR_CONTROLBYTES1);
        spin_unlock_bh(&ep->htc->tx_lock);
}

int ath12k_htc_send(struct ath12k_htc *htc,
                    enum ath12k_htc_ep_id eid,
                    struct sk_buff *skb)
{
        struct ath12k_htc_ep *ep = &htc->endpoint[eid];
        struct ath12k_skb_cb *skb_cb = ATH12K_SKB_CB(skb);
        struct device *dev = htc->ab->dev;
        struct ath12k_base *ab = htc->ab;
        int credits = 0;
        int ret;

        if (eid >= ATH12K_HTC_EP_COUNT) {
                ath12k_warn(ab, "Invalid endpoint id: %d\n", eid);
                return -ENOENT;
        }

        skb_push(skb, sizeof(struct ath12k_htc_hdr));

        if (ep->tx_credit_flow_enabled) {
                credits = DIV_ROUND_UP(skb->len, htc->target_credit_size);
                spin_lock_bh(&htc->tx_lock);
                if (ep->tx_credits < credits) {
                        ath12k_dbg(ab, ATH12K_DBG_HTC,
                                   "htc insufficient credits ep %d required %d available %d\n",
                                   eid, credits, ep->tx_credits);
                        spin_unlock_bh(&htc->tx_lock);
                        ret = -EAGAIN;
                        goto err_pull;
                }
                ep->tx_credits -= credits;
                ath12k_dbg(ab, ATH12K_DBG_HTC,
                           "htc ep %d consumed %d credits (total %d)\n",
                           eid, credits, ep->tx_credits);
                spin_unlock_bh(&htc->tx_lock);
        }

        ath12k_htc_prepare_tx_skb(ep, skb);

        skb_cb->paddr = dma_map_single(dev, skb->data, skb->len, DMA_TO_DEVICE);
        ret = dma_mapping_error(dev, skb_cb->paddr);
        if (ret) {
                ret = -EIO;
                goto err_credits;
        }

        ret = ath12k_ce_send(htc->ab, skb, ep->ul_pipe_id, ep->eid);
        if (ret)
                goto err_unmap;

        return 0;

err_unmap:
        dma_unmap_single(dev, skb_cb->paddr, skb->len, DMA_TO_DEVICE);
err_credits:
        if (ep->tx_credit_flow_enabled) {
                spin_lock_bh(&htc->tx_lock);
                ep->tx_credits += credits;
                ath12k_dbg(ab, ATH12K_DBG_HTC,
                           "htc ep %d reverted %d credits back (total %d)\n",
                           eid, credits, ep->tx_credits);
                spin_unlock_bh(&htc->tx_lock);

                if (ep->ep_ops.ep_tx_credits)
                        ep->ep_ops.ep_tx_credits(htc->ab);
        }
err_pull:
        skb_pull(skb, sizeof(struct ath12k_htc_hdr));
        return ret;
}

static void
ath12k_htc_process_credit_report(struct ath12k_htc *htc,
                                 const struct ath12k_htc_credit_report *report,
                                 int len,
                                 enum ath12k_htc_ep_id eid)
{
        struct ath12k_base *ab = htc->ab;
        struct ath12k_htc_ep *ep;
        int i, n_reports;

        if (len % sizeof(*report))
                ath12k_warn(ab, "Uneven credit report len %d", len);

        n_reports = len / sizeof(*report);

        spin_lock_bh(&htc->tx_lock);
        for (i = 0; i < n_reports; i++, report++) {
                if (report->eid >= ATH12K_HTC_EP_COUNT)
                        break;

                ep = &htc->endpoint[report->eid];
                ep->tx_credits += report->credits;

                ath12k_dbg(ab, ATH12K_DBG_HTC, "htc ep %d got %d credits (total %d)\n",
                           report->eid, report->credits, ep->tx_credits);

                if (ep->ep_ops.ep_tx_credits) {
                        spin_unlock_bh(&htc->tx_lock);
                        ep->ep_ops.ep_tx_credits(htc->ab);
                        spin_lock_bh(&htc->tx_lock);
                }
        }
        spin_unlock_bh(&htc->tx_lock);
}

static int ath12k_htc_process_trailer(struct ath12k_htc *htc,
                                      u8 *buffer,
                                      int length,
                                      enum ath12k_htc_ep_id src_eid)
{
        struct ath12k_base *ab = htc->ab;
        int status = 0;
        struct ath12k_htc_record *record;
        size_t len;

        while (length > 0) {
                record = (struct ath12k_htc_record *)buffer;

                if (length < sizeof(record->hdr)) {
                        status = -EINVAL;
                        break;
                }

                if (record->hdr.len > length) {
                        /* no room left in buffer for record */
                        ath12k_warn(ab, "Invalid record length: %d\n",
                                    record->hdr.len);
                        status = -EINVAL;
                        break;
                }

                switch (record->hdr.id) {
                case ATH12K_HTC_RECORD_CREDITS:
                        len = sizeof(struct ath12k_htc_credit_report);
                        if (record->hdr.len < len) {
                                ath12k_warn(ab, "Credit report too long\n");
                                status = -EINVAL;
                                break;
                        }
                        ath12k_htc_process_credit_report(htc,
                                                         record->credit_report,
                                                         record->hdr.len,
                                                         src_eid);
                        break;
                default:
                        ath12k_warn(ab, "Unhandled record: id:%d length:%d\n",
                                    record->hdr.id, record->hdr.len);
                        break;
                }

                if (status)
                        break;

                /* multiple records may be present in a trailer */
                buffer += sizeof(record->hdr) + record->hdr.len;
                length -= sizeof(record->hdr) + record->hdr.len;
        }

        return status;
}

static void ath12k_htc_suspend_complete(struct ath12k_base *ab, bool ack)
{
        ath12k_dbg(ab, ATH12K_DBG_BOOT, "boot suspend complete %d\n", ack);

        if (ack)
                set_bit(ATH12K_FLAG_HTC_SUSPEND_COMPLETE, &ab->dev_flags);
        else
                clear_bit(ATH12K_FLAG_HTC_SUSPEND_COMPLETE, &ab->dev_flags);

        complete(&ab->htc_suspend);
}

static void ath12k_htc_wakeup_from_suspend(struct ath12k_base *ab)
{
        ath12k_dbg(ab, ATH12K_DBG_BOOT, "boot wakeup from suspend is received\n");
}

void ath12k_htc_rx_completion_handler(struct ath12k_base *ab,
                                      struct sk_buff *skb)
{
        int status = 0;
        struct ath12k_htc *htc = &ab->htc;
        struct ath12k_htc_hdr *hdr;
        struct ath12k_htc_ep *ep;
        u16 payload_len;
        u32 trailer_len = 0;
        size_t min_len;
        u8 eid;
        bool trailer_present;

        hdr = (struct ath12k_htc_hdr *)skb->data;
        skb_pull(skb, sizeof(*hdr));

        eid = le32_get_bits(hdr->htc_info, HTC_HDR_ENDPOINTID);

        if (eid >= ATH12K_HTC_EP_COUNT) {
                ath12k_warn(ab, "HTC Rx: invalid eid %d\n", eid);
                goto out;
        }

        ep = &htc->endpoint[eid];

        payload_len = le32_get_bits(hdr->htc_info, HTC_HDR_PAYLOADLEN);

        if (payload_len + sizeof(*hdr) > ATH12K_HTC_MAX_LEN) {
                ath12k_warn(ab, "HTC rx frame too long, len: %zu\n",
                            payload_len + sizeof(*hdr));
                goto out;
        }

        if (skb->len < payload_len) {
                ath12k_warn(ab, "HTC Rx: insufficient length, got %d, expected %d\n",
                            skb->len, payload_len);
                goto out;
        }

        /* get flags to check for trailer */
        trailer_present = le32_get_bits(hdr->htc_info, HTC_HDR_FLAGS) &
                          ATH12K_HTC_FLAG_TRAILER_PRESENT;

        if (trailer_present) {
                u8 *trailer;

                trailer_len = le32_get_bits(hdr->ctrl_info,
                                            HTC_HDR_CONTROLBYTES0);
                min_len = sizeof(struct ath12k_htc_record_hdr);

                if ((trailer_len < min_len) ||
                    (trailer_len > payload_len)) {
                        ath12k_warn(ab, "Invalid trailer length: %d\n",
                                    trailer_len);
                        goto out;
                }

                trailer = (u8 *)hdr;
                trailer += sizeof(*hdr);
                trailer += payload_len;
                trailer -= trailer_len;
                status = ath12k_htc_process_trailer(htc, trailer,
                                                    trailer_len, eid);
                if (status)
                        goto out;

                skb_trim(skb, skb->len - trailer_len);
        }

        if (trailer_len >= payload_len)
                /* zero length packet with trailer data, just drop these */
                goto out;

        if (eid == ATH12K_HTC_EP_0) {
                struct ath12k_htc_msg *msg = (struct ath12k_htc_msg *)skb->data;

                switch (le32_get_bits(msg->msg_svc_id, HTC_MSG_MESSAGEID)) {
                case ATH12K_HTC_MSG_READY_ID:
                case ATH12K_HTC_MSG_CONNECT_SERVICE_RESP_ID:
                        /* handle HTC control message */
                        if (completion_done(&htc->ctl_resp)) {
                                /* this is a fatal error, target should not be
                                 * sending unsolicited messages on the ep 0
                                 */
                                ath12k_warn(ab, "HTC rx ctrl still processing\n");
                                complete(&htc->ctl_resp);
                                goto out;
                        }

                        htc->control_resp_len =
                                min_t(int, skb->len,
                                      ATH12K_HTC_MAX_CTRL_MSG_LEN);

                        memcpy(htc->control_resp_buffer, skb->data,
                               htc->control_resp_len);

                        complete(&htc->ctl_resp);
                        break;
                case ATH12K_HTC_MSG_SEND_SUSPEND_COMPLETE:
                        ath12k_htc_suspend_complete(ab, true);
                        break;
                case ATH12K_HTC_MSG_NACK_SUSPEND:
                        ath12k_htc_suspend_complete(ab, false);
                        break;
                case ATH12K_HTC_MSG_WAKEUP_FROM_SUSPEND_ID:
                        ath12k_htc_wakeup_from_suspend(ab);
                        break;
                default:
                        ath12k_warn(ab, "ignoring unsolicited htc ep0 event %u\n",
                                    le32_get_bits(msg->msg_svc_id, HTC_MSG_MESSAGEID));
                        break;
                }
                goto out;
        }

        ath12k_dbg(ab, ATH12K_DBG_HTC, "htc rx completion ep %d skb %p\n",
                   eid, skb);
        ep->ep_ops.ep_rx_complete(ab, skb);

        /* poll tx completion for interrupt disabled CE's */
        ath12k_ce_poll_send_completed(ab, ep->ul_pipe_id);

        /* skb is now owned by the rx completion handler */
        skb = NULL;
out:
        kfree_skb(skb);
}
EXPORT_SYMBOL(ath12k_htc_rx_completion_handler);

static void ath12k_htc_control_rx_complete(struct ath12k_base *ab,
                                           struct sk_buff *skb)
{
        /* This is unexpected. FW is not supposed to send regular rx on this
         * endpoint.
         */
        ath12k_warn(ab, "unexpected htc rx\n");
        kfree_skb(skb);
}

static const char *htc_service_name(enum ath12k_htc_svc_id id)
{
        switch (id) {
        case ATH12K_HTC_SVC_ID_RESERVED:
                return "Reserved";
        case ATH12K_HTC_SVC_ID_RSVD_CTRL:
                return "Control";
        case ATH12K_HTC_SVC_ID_WMI_CONTROL:
                return "WMI";
        case ATH12K_HTC_SVC_ID_WMI_DATA_BE:
                return "DATA BE";
        case ATH12K_HTC_SVC_ID_WMI_DATA_BK:
                return "DATA BK";
        case ATH12K_HTC_SVC_ID_WMI_DATA_VI:
                return "DATA VI";
        case ATH12K_HTC_SVC_ID_WMI_DATA_VO:
                return "DATA VO";
        case ATH12K_HTC_SVC_ID_WMI_CONTROL_MAC1:
                return "WMI MAC1";
        case ATH12K_HTC_SVC_ID_WMI_CONTROL_MAC2:
                return "WMI MAC2";
        case ATH12K_HTC_SVC_ID_NMI_CONTROL:
                return "NMI Control";
        case ATH12K_HTC_SVC_ID_NMI_DATA:
                return "NMI Data";
        case ATH12K_HTC_SVC_ID_HTT_DATA_MSG:
                return "HTT Data";
        case ATH12K_HTC_SVC_ID_TEST_RAW_STREAMS:
                return "RAW";
        case ATH12K_HTC_SVC_ID_IPA_TX:
                return "IPA TX";
        case ATH12K_HTC_SVC_ID_PKT_LOG:
                return "PKT LOG";
        case ATH12K_HTC_SVC_ID_WMI_CONTROL_DIAG:
                return "WMI DIAG";
        }

        return "Unknown";
}

static void ath12k_htc_reset_endpoint_states(struct ath12k_htc *htc)
{
        struct ath12k_htc_ep *ep;
        int i;

        for (i = ATH12K_HTC_EP_0; i < ATH12K_HTC_EP_COUNT; i++) {
                ep = &htc->endpoint[i];
                ep->service_id = ATH12K_HTC_SVC_ID_UNUSED;
                ep->max_ep_message_len = 0;
                ep->max_tx_queue_depth = 0;
                ep->eid = i;
                ep->htc = htc;
                ep->tx_credit_flow_enabled = true;
        }
}

static u8 ath12k_htc_get_credit_allocation(struct ath12k_htc *htc,
                                           u16 service_id)
{
        struct ath12k_htc_svc_tx_credits *serv_entry;
        u8 i, allocation = 0;

        serv_entry = htc->service_alloc_table;

        for (i = 0; i < ATH12K_HTC_MAX_SERVICE_ALLOC_ENTRIES; i++) {
                if (serv_entry[i].service_id == service_id) {
                        allocation = serv_entry[i].credit_allocation;
                        break;
                }
        }

        return allocation;
}

static int ath12k_htc_setup_target_buffer_assignments(struct ath12k_htc *htc)
{
        struct ath12k_htc_svc_tx_credits *serv_entry;
        static const u32 svc_id[] = {
                                        ATH12K_HTC_SVC_ID_WMI_CONTROL,
                                        ATH12K_HTC_SVC_ID_WMI_CONTROL_MAC1,
                                        ATH12K_HTC_SVC_ID_WMI_CONTROL_MAC2,
                                };
        int i, credits;

        credits = htc->total_transmit_credits;
        serv_entry = htc->service_alloc_table;

        if ((htc->wmi_ep_count == 0) ||
            (htc->wmi_ep_count > ARRAY_SIZE(svc_id)))
                return -EINVAL;

        /* Divide credits among number of endpoints for WMI */
        credits = credits / htc->wmi_ep_count;
        for (i = 0; i < htc->wmi_ep_count; i++) {
                serv_entry[i].service_id = svc_id[i];
                serv_entry[i].credit_allocation = credits;
        }

        return 0;
}

int ath12k_htc_wait_target(struct ath12k_htc *htc)
{
        int i, status = 0;
        struct ath12k_base *ab = htc->ab;
        unsigned long time_left;
        struct ath12k_htc_ready *ready;
        u16 message_id;
        u16 credit_count;
        u16 credit_size;

        time_left = wait_for_completion_timeout(&htc->ctl_resp,
                                                ATH12K_HTC_WAIT_TIMEOUT_HZ);
        if (!time_left) {
                ath12k_warn(ab, "failed to receive control response completion, polling..\n");

                for (i = 0; i < ab->hw_params->ce_count; i++)
                        ath12k_ce_per_engine_service(htc->ab, i);

                time_left =
                        wait_for_completion_timeout(&htc->ctl_resp,
                                                    ATH12K_HTC_WAIT_TIMEOUT_HZ);

                if (!time_left)
                        status = -ETIMEDOUT;
        }

        if (status < 0) {
                ath12k_warn(ab, "ctl_resp never came in (%d)\n", status);
                return status;
        }

        if (htc->control_resp_len < sizeof(*ready)) {
                ath12k_warn(ab, "Invalid HTC ready msg len:%d\n",
                            htc->control_resp_len);
                return -ECOMM;
        }

        ready = (struct ath12k_htc_ready *)htc->control_resp_buffer;
        message_id = le32_get_bits(ready->id_credit_count, HTC_MSG_MESSAGEID);
        credit_count = le32_get_bits(ready->id_credit_count,
                                     HTC_READY_MSG_CREDITCOUNT);
        credit_size = le32_get_bits(ready->size_ep, HTC_READY_MSG_CREDITSIZE);

        if (message_id != ATH12K_HTC_MSG_READY_ID) {
                ath12k_warn(ab, "Invalid HTC ready msg: 0x%x\n", message_id);
                return -ECOMM;
        }

        htc->total_transmit_credits = credit_count;
        htc->target_credit_size = credit_size;

        ath12k_dbg(ab, ATH12K_DBG_HTC,
                   "Target ready! transmit resources: %d size:%d\n",
                   htc->total_transmit_credits, htc->target_credit_size);

        if ((htc->total_transmit_credits == 0) ||
            (htc->target_credit_size == 0)) {
                ath12k_warn(ab, "Invalid credit size received\n");
                return -ECOMM;
        }

        ath12k_htc_setup_target_buffer_assignments(htc);

        return 0;
}

int ath12k_htc_connect_service(struct ath12k_htc *htc,
                               struct ath12k_htc_svc_conn_req *conn_req,
                               struct ath12k_htc_svc_conn_resp *conn_resp)
{
        struct ath12k_base *ab = htc->ab;
        struct ath12k_htc_conn_svc *req_msg;
        struct ath12k_htc_conn_svc_resp resp_msg_dummy;
        struct ath12k_htc_conn_svc_resp *resp_msg = &resp_msg_dummy;
        enum ath12k_htc_ep_id assigned_eid = ATH12K_HTC_EP_COUNT;
        struct ath12k_htc_ep *ep;
        struct sk_buff *skb;
        unsigned int max_msg_size = 0;
        int length, status;
        unsigned long time_left;
        bool disable_credit_flow_ctrl = false;
        u16 message_id, service_id, flags = 0;
        u8 tx_alloc = 0;

        /* special case for HTC pseudo control service */
        if (conn_req->service_id == ATH12K_HTC_SVC_ID_RSVD_CTRL) {
                disable_credit_flow_ctrl = true;
                assigned_eid = ATH12K_HTC_EP_0;
                max_msg_size = ATH12K_HTC_MAX_CTRL_MSG_LEN;
                memset(&resp_msg_dummy, 0, sizeof(resp_msg_dummy));
                goto setup;
        }

        tx_alloc = ath12k_htc_get_credit_allocation(htc,
                                                    conn_req->service_id);
        if (!tx_alloc)
                ath12k_dbg(ab, ATH12K_DBG_BOOT,
                           "boot htc service %s does not allocate target credits\n",
                           htc_service_name(conn_req->service_id));

        skb = ath12k_htc_build_tx_ctrl_skb();
        if (!skb) {
                ath12k_warn(ab, "Failed to allocate HTC packet\n");
                return -ENOMEM;
        }

        length = sizeof(*req_msg);
        skb_put(skb, length);
        memset(skb->data, 0, length);

        req_msg = (struct ath12k_htc_conn_svc *)skb->data;
        req_msg->msg_svc_id = le32_encode_bits(ATH12K_HTC_MSG_CONNECT_SERVICE_ID,
                                               HTC_MSG_MESSAGEID);

        flags |= u32_encode_bits(tx_alloc, ATH12K_HTC_CONN_FLAGS_RECV_ALLOC);

        /* Only enable credit flow control for WMI ctrl service */
        if (!(conn_req->service_id == ATH12K_HTC_SVC_ID_WMI_CONTROL ||
              conn_req->service_id == ATH12K_HTC_SVC_ID_WMI_CONTROL_MAC1 ||
              conn_req->service_id == ATH12K_HTC_SVC_ID_WMI_CONTROL_MAC2)) {
                flags |= ATH12K_HTC_CONN_FLAGS_DISABLE_CREDIT_FLOW_CTRL;
                disable_credit_flow_ctrl = true;
        }

        req_msg->flags_len = le32_encode_bits(flags, HTC_SVC_MSG_CONNECTIONFLAGS);
        req_msg->msg_svc_id |= le32_encode_bits(conn_req->service_id,
                                                HTC_SVC_MSG_SERVICE_ID);

        reinit_completion(&htc->ctl_resp);

        status = ath12k_htc_send(htc, ATH12K_HTC_EP_0, skb);
        if (status) {
                kfree_skb(skb);
                return status;
        }

        /* wait for response */
        time_left = wait_for_completion_timeout(&htc->ctl_resp,
                                                ATH12K_HTC_CONN_SVC_TIMEOUT_HZ);
        if (!time_left) {
                ath12k_err(ab, "Service connect timeout\n");
                return -ETIMEDOUT;
        }

        /* we controlled the buffer creation, it's aligned */
        resp_msg = (struct ath12k_htc_conn_svc_resp *)htc->control_resp_buffer;
        message_id = le32_get_bits(resp_msg->msg_svc_id, HTC_MSG_MESSAGEID);
        service_id = le32_get_bits(resp_msg->msg_svc_id,
                                   HTC_SVC_RESP_MSG_SERVICEID);

        if ((message_id != ATH12K_HTC_MSG_CONNECT_SERVICE_RESP_ID) ||
            (htc->control_resp_len < sizeof(*resp_msg))) {
                ath12k_err(ab, "Invalid resp message ID 0x%x", message_id);
                return -EPROTO;
        }

        ath12k_dbg(ab, ATH12K_DBG_HTC,
                   "HTC Service %s connect response: status: %u, assigned ep: %u\n",
                   htc_service_name(service_id),
                   le32_get_bits(resp_msg->flags_len, HTC_SVC_RESP_MSG_STATUS),
                   le32_get_bits(resp_msg->flags_len, HTC_SVC_RESP_MSG_ENDPOINTID));

        conn_resp->connect_resp_code = le32_get_bits(resp_msg->flags_len,
                                                     HTC_SVC_RESP_MSG_STATUS);

        /* check response status */
        if (conn_resp->connect_resp_code != ATH12K_HTC_CONN_SVC_STATUS_SUCCESS) {
                ath12k_err(ab, "HTC Service %s connect request failed: 0x%x)\n",
                           htc_service_name(service_id),
                       conn_resp->connect_resp_code);
                return -EPROTO;
        }

        assigned_eid = le32_get_bits(resp_msg->flags_len,
                                     HTC_SVC_RESP_MSG_ENDPOINTID);

        max_msg_size = le32_get_bits(resp_msg->flags_len,
                                     HTC_SVC_RESP_MSG_MAXMSGSIZE);

setup:

        if (assigned_eid >= ATH12K_HTC_EP_COUNT)
                return -EPROTO;

        if (max_msg_size == 0)
                return -EPROTO;

        ep = &htc->endpoint[assigned_eid];
        ep->eid = assigned_eid;

        if (ep->service_id != ATH12K_HTC_SVC_ID_UNUSED)
                return -EPROTO;

        /* return assigned endpoint to caller */
        conn_resp->eid = assigned_eid;
        conn_resp->max_msg_len = le32_get_bits(resp_msg->flags_len,
                                               HTC_SVC_RESP_MSG_MAXMSGSIZE);

        /* setup the endpoint */
        ep->service_id = conn_req->service_id;
        ep->max_tx_queue_depth = conn_req->max_send_queue_depth;
        ep->max_ep_message_len = le32_get_bits(resp_msg->flags_len,
                                               HTC_SVC_RESP_MSG_MAXMSGSIZE);
        ep->tx_credits = tx_alloc;

        /* copy all the callbacks */
        ep->ep_ops = conn_req->ep_ops;

        status = ath12k_hif_map_service_to_pipe(htc->ab,
                                                ep->service_id,
                                                &ep->ul_pipe_id,
                                                &ep->dl_pipe_id);
        if (status)
                return status;

        ath12k_dbg(ab, ATH12K_DBG_BOOT,
                   "boot htc service '%s' ul pipe %d dl pipe %d eid %d ready\n",
                   htc_service_name(ep->service_id), ep->ul_pipe_id,
                   ep->dl_pipe_id, ep->eid);

        if (disable_credit_flow_ctrl && ep->tx_credit_flow_enabled) {
                ep->tx_credit_flow_enabled = false;
                ath12k_dbg(ab, ATH12K_DBG_BOOT,
                           "boot htc service '%s' eid %d TX flow control disabled\n",
                           htc_service_name(ep->service_id), assigned_eid);
        }

        return status;
}

int ath12k_htc_start(struct ath12k_htc *htc)
{
        struct sk_buff *skb;
        int status;
        struct ath12k_base *ab = htc->ab;
        struct ath12k_htc_setup_complete_extended *msg;

        skb = ath12k_htc_build_tx_ctrl_skb();
        if (!skb)
                return -ENOMEM;

        skb_put(skb, sizeof(*msg));
        memset(skb->data, 0, skb->len);

        msg = (struct ath12k_htc_setup_complete_extended *)skb->data;
        msg->msg_id = le32_encode_bits(ATH12K_HTC_MSG_SETUP_COMPLETE_EX_ID,
                                       HTC_MSG_MESSAGEID);

        ath12k_dbg(ab, ATH12K_DBG_HTC, "HTC is using TX credit flow control\n");

        status = ath12k_htc_send(htc, ATH12K_HTC_EP_0, skb);
        if (status) {
                kfree_skb(skb);
                return status;
        }

        return 0;
}

int ath12k_htc_init(struct ath12k_base *ab)
{
        struct ath12k_htc *htc = &ab->htc;
        struct ath12k_htc_svc_conn_req conn_req = { };
        struct ath12k_htc_svc_conn_resp conn_resp = { };
        int ret;

        spin_lock_init(&htc->tx_lock);

        ath12k_htc_reset_endpoint_states(htc);

        htc->ab = ab;

        switch (ab->wmi_ab.preferred_hw_mode) {
        case WMI_HOST_HW_MODE_SINGLE:
                htc->wmi_ep_count = 1;
                break;
        case WMI_HOST_HW_MODE_DBS:
        case WMI_HOST_HW_MODE_DBS_OR_SBS:
                htc->wmi_ep_count = 2;
                break;
        case WMI_HOST_HW_MODE_DBS_SBS:
                htc->wmi_ep_count = 3;
                break;
        default:
                htc->wmi_ep_count = ab->hw_params->max_radios;
                break;
        }

        /* setup our pseudo HTC control endpoint connection */
        conn_req.ep_ops.ep_tx_complete = ath12k_htc_control_tx_complete;
        conn_req.ep_ops.ep_rx_complete = ath12k_htc_control_rx_complete;
        conn_req.max_send_queue_depth = ATH12K_NUM_CONTROL_TX_BUFFERS;
        conn_req.service_id = ATH12K_HTC_SVC_ID_RSVD_CTRL;

        /* connect fake service */
        ret = ath12k_htc_connect_service(htc, &conn_req, &conn_resp);
        if (ret) {
                ath12k_err(ab, "could not connect to htc service (%d)\n", ret);
                return ret;
        }

        init_completion(&htc->ctl_resp);

        return 0;
}