1 files changed, 1000 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath10k/htc.c b/drivers/net/wireless/ath/ath10k/htc.c
new file mode 100644
index 000000000000..74363c949392
--- /dev/null
+++ b/drivers/net/wireless/ath/ath10k/htc.c
@@ -0,0 +1,1000 @@
+/*
+ * Copyright (c) 2005-2011 Atheros Communications Inc.
+ * Copyright (c) 2011-2013 Qualcomm Atheros, 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 "core.h"
+#include "hif.h"
+#include "debug.h"
+
+/********/
+/* Send */
+/********/
+
+static inline void ath10k_htc_send_complete_check(struct ath10k_htc_ep *ep,
+						  int force)
+{
+	/*
+	 * Check whether HIF has any prior sends that have finished,
+	 * have not had the post-processing done.
+	 */
+	ath10k_hif_send_complete_check(ep->htc->ar, ep->ul_pipe_id, force);
+}
+
+static void ath10k_htc_control_tx_complete(struct ath10k *ar,
+					   struct sk_buff *skb)
+{
+	kfree_skb(skb);
+}
+
+static struct sk_buff *ath10k_htc_build_tx_ctrl_skb(void *ar)
+{
+	struct sk_buff *skb;
+	struct ath10k_skb_cb *skb_cb;
+
+	skb = dev_alloc_skb(ATH10K_HTC_CONTROL_BUFFER_SIZE);
+	if (!skb) {
+		ath10k_warn("Unable to allocate ctrl skb\n");
+		return NULL;
+	}
+
+	skb_reserve(skb, 20); /* FIXME: why 20 bytes? */
+	WARN_ONCE((unsigned long)skb->data & 3, "unaligned skb");
+
+	skb_cb = ATH10K_SKB_CB(skb);
+	memset(skb_cb, 0, sizeof(*skb_cb));
+
+	ath10k_dbg(ATH10K_DBG_HTC, "%s: skb %p\n", __func__, skb);
+	return skb;
+}
+
+static inline void ath10k_htc_restore_tx_skb(struct ath10k_htc *htc,
+					     struct sk_buff *skb)
+{
+	ath10k_skb_unmap(htc->ar->dev, skb);
+	skb_pull(skb, sizeof(struct ath10k_htc_hdr));
+}
+
+static void ath10k_htc_notify_tx_completion(struct ath10k_htc_ep *ep,
+					    struct sk_buff *skb)
+{
+	ath10k_dbg(ATH10K_DBG_HTC, "%s: ep %d skb %p\n", __func__,
+		   ep->eid, skb);
+
+	ath10k_htc_restore_tx_skb(ep->htc, skb);
+
+	if (!ep->ep_ops.ep_tx_complete) {
+		ath10k_warn("no tx handler for eid %d\n", ep->eid);
+		dev_kfree_skb_any(skb);
+		return;
+	}
+
+	ep->ep_ops.ep_tx_complete(ep->htc->ar, skb);
+}
+
+/* assumes tx_lock is held */
+static bool ath10k_htc_ep_need_credit_update(struct ath10k_htc_ep *ep)
+{
+	if (!ep->tx_credit_flow_enabled)
+		return false;
+	if (ep->tx_credits >= ep->tx_credits_per_max_message)
+		return false;
+
+	ath10k_dbg(ATH10K_DBG_HTC, "HTC: endpoint %d needs credit update\n",
+		   ep->eid);
+	return true;
+}
+
+static void ath10k_htc_prepare_tx_skb(struct ath10k_htc_ep *ep,
+				      struct sk_buff *skb)
+{
+	struct ath10k_htc_hdr *hdr;
+
+	hdr = (struct ath10k_htc_hdr *)skb->data;
+	memset(hdr, 0, sizeof(*hdr));
+
+	hdr->eid = ep->eid;
+	hdr->len = __cpu_to_le16(skb->len - sizeof(*hdr));
+
+	spin_lock_bh(&ep->htc->tx_lock);
+	hdr->seq_no = ep->seq_no++;
+
+	if (ath10k_htc_ep_need_credit_update(ep))
+		hdr->flags |= ATH10K_HTC_FLAG_NEED_CREDIT_UPDATE;
+
+	spin_unlock_bh(&ep->htc->tx_lock);
+}
+
+static int ath10k_htc_issue_skb(struct ath10k_htc *htc,
+				struct ath10k_htc_ep *ep,
+				struct sk_buff *skb,
+				u8 credits)
+{
+	struct ath10k_skb_cb *skb_cb = ATH10K_SKB_CB(skb);
+	int ret;
+
+	ath10k_dbg(ATH10K_DBG_HTC, "%s: ep %d skb %p\n", __func__,
+		   ep->eid, skb);
+
+	ath10k_htc_prepare_tx_skb(ep, skb);
+
+	ret = ath10k_skb_map(htc->ar->dev, skb);
+	if (ret)
+		goto err;
+
+	ret = ath10k_hif_send_head(htc->ar,
+				   ep->ul_pipe_id,
+				   ep->eid,
+				   skb->len,
+				   skb);
+	if (unlikely(ret))
+		goto err;
+
+	return 0;
+err:
+	ath10k_warn("HTC issue failed: %d\n", ret);
+
+	spin_lock_bh(&htc->tx_lock);
+	ep->tx_credits += credits;
+	spin_unlock_bh(&htc->tx_lock);
+
+	/* this is the simplest way to handle out-of-resources for non-credit
+	 * based endpoints. credit based endpoints can still get -ENOSR, but
+	 * this is highly unlikely as credit reservation should prevent that */
+	if (ret == -ENOSR) {
+		spin_lock_bh(&htc->tx_lock);
+		__skb_queue_head(&ep->tx_queue, skb);
+		spin_unlock_bh(&htc->tx_lock);
+
+		return ret;
+	}
+
+	skb_cb->is_aborted = true;
+	ath10k_htc_notify_tx_completion(ep, skb);
+
+	return ret;
+}
+
+static struct sk_buff *ath10k_htc_get_skb_credit_based(struct ath10k_htc *htc,
+						       struct ath10k_htc_ep *ep,
+						       u8 *credits)
+{
+	struct sk_buff *skb;
+	struct ath10k_skb_cb *skb_cb;
+	int credits_required;
+	int remainder;
+	unsigned int transfer_len;
+
+	lockdep_assert_held(&htc->tx_lock);
+
+	skb = __skb_dequeue(&ep->tx_queue);
+	if (!skb)
+		return NULL;
+
+	skb_cb = ATH10K_SKB_CB(skb);
+	transfer_len = skb->len;
+
+	if (likely(transfer_len <= htc->target_credit_size)) {
+		credits_required = 1;
+	} else {
+		/* figure out how many credits this message requires */
+		credits_required = transfer_len / htc->target_credit_size;
+		remainder = transfer_len % htc->target_credit_size;
+
+		if (remainder)
+			credits_required++;
+	}
+
+	ath10k_dbg(ATH10K_DBG_HTC, "Credits required %d got %d\n",
+		   credits_required, ep->tx_credits);
+
+	if (ep->tx_credits < credits_required) {
+		__skb_queue_head(&ep->tx_queue, skb);
+		return NULL;
+	}
+
+	ep->tx_credits -= credits_required;
+	*credits = credits_required;
+	return skb;
+}
+
+static void ath10k_htc_send_work(struct work_struct *work)
+{
+	struct ath10k_htc_ep *ep = container_of(work,
+					struct ath10k_htc_ep, send_work);
+	struct ath10k_htc *htc = ep->htc;
+	struct sk_buff *skb;
+	u8 credits = 0;
+	int ret;
+
+	while (true) {
+		if (ep->ul_is_polled)
+			ath10k_htc_send_complete_check(ep, 0);
+
+		spin_lock_bh(&htc->tx_lock);
+		if (ep->tx_credit_flow_enabled)
+			skb = ath10k_htc_get_skb_credit_based(htc, ep,
+							      &credits);
+		else
+			skb = __skb_dequeue(&ep->tx_queue);
+		spin_unlock_bh(&htc->tx_lock);
+
+		if (!skb)
+			break;
+
+		ret = ath10k_htc_issue_skb(htc, ep, skb, credits);
+		if (ret == -ENOSR)
+			break;
+	}
+}
+
+int ath10k_htc_send(struct ath10k_htc *htc,
+		    enum ath10k_htc_ep_id eid,
+		    struct sk_buff *skb)
+{
+	struct ath10k_htc_ep *ep = &htc->endpoint[eid];
+
+	if (eid >= ATH10K_HTC_EP_COUNT) {
+		ath10k_warn("Invalid endpoint id: %d\n", eid);
+		return -ENOENT;
+	}
+
+	skb_push(skb, sizeof(struct ath10k_htc_hdr));
+
+	spin_lock_bh(&htc->tx_lock);
+	__skb_queue_tail(&ep->tx_queue, skb);
+	spin_unlock_bh(&htc->tx_lock);
+
+	queue_work(htc->ar->workqueue, &ep->send_work);
+	return 0;
+}
+
+static int ath10k_htc_tx_completion_handler(struct ath10k *ar,
+					    struct sk_buff *skb,
+					    unsigned int eid)
+{
+	struct ath10k_htc *htc = ar->htc;
+	struct ath10k_htc_ep *ep = &htc->endpoint[eid];
+	bool stopping;
+
+	ath10k_htc_notify_tx_completion(ep, skb);
+	/* the skb now belongs to the completion handler */
+
+	spin_lock_bh(&htc->tx_lock);
+	stopping = htc->stopping;
+	spin_unlock_bh(&htc->tx_lock);
+
+	if (!ep->tx_credit_flow_enabled && !stopping)
+		/*
+		 * note: when using TX credit flow, the re-checking of
+		 * queues happens when credits flow back from the target.
+		 * in the non-TX credit case, we recheck after the packet
+		 * completes
+		 */
+		queue_work(ar->workqueue, &ep->send_work);
+
+	return 0;
+}
+
+/* flush endpoint TX queue */
+static void ath10k_htc_flush_endpoint_tx(struct ath10k_htc *htc,
+					 struct ath10k_htc_ep *ep)
+{
+	struct sk_buff *skb;
+	struct ath10k_skb_cb *skb_cb;
+
+	spin_lock_bh(&htc->tx_lock);
+	for (;;) {
+		skb = __skb_dequeue(&ep->tx_queue);
+		if (!skb)
+			break;
+
+		skb_cb = ATH10K_SKB_CB(skb);
+		skb_cb->is_aborted = true;
+		ath10k_htc_notify_tx_completion(ep, skb);
+	}
+	spin_unlock_bh(&htc->tx_lock);
+
+	cancel_work_sync(&ep->send_work);
+}
+
+/***********/
+/* Receive */
+/***********/
+
+static void
+ath10k_htc_process_credit_report(struct ath10k_htc *htc,
+				 const struct ath10k_htc_credit_report *report,
+				 int len,
+				 enum ath10k_htc_ep_id eid)
+{
+	struct ath10k_htc_ep *ep;
+	int i, n_reports;
+
+	if (len % sizeof(*report))
+		ath10k_warn("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 >= ATH10K_HTC_EP_COUNT)
+			break;
+
+		ath10k_dbg(ATH10K_DBG_HTC, "ep %d got %d credits\n",
+			   report->eid, report->credits);
+
+		ep = &htc->endpoint[report->eid];
+		ep->tx_credits += report->credits;
+
+		if (ep->tx_credits && !skb_queue_empty(&ep->tx_queue))
+			queue_work(htc->ar->workqueue, &ep->send_work);
+	}
+	spin_unlock_bh(&htc->tx_lock);
+}
+
+static int ath10k_htc_process_trailer(struct ath10k_htc *htc,
+				      u8 *buffer,
+				      int length,
+				      enum ath10k_htc_ep_id src_eid)
+{
+	int status = 0;
+	struct ath10k_htc_record *record;
+	u8 *orig_buffer;
+	int orig_length;
+	size_t len;
+
+	orig_buffer = buffer;
+	orig_length = length;
+
+	while (length > 0) {
+		record = (struct ath10k_htc_record *)buffer;
+
+		if (length < sizeof(record->hdr)) {
+			status = -EINVAL;
+			break;
+		}
+
+		if (record->hdr.len > length) {
+			/* no room left in buffer for record */
+			ath10k_warn("Invalid record length: %d\n",
+				    record->hdr.len);
+			status = -EINVAL;
+			break;
+		}
+
+		switch (record->hdr.id) {
+		case ATH10K_HTC_RECORD_CREDITS:
+			len = sizeof(struct ath10k_htc_credit_report);
+			if (record->hdr.len < len) {
+				ath10k_warn("Credit report too long\n");
+				status = -EINVAL;
+				break;
+			}
+			ath10k_htc_process_credit_report(htc,
+							 record->credit_report,
+							 record->hdr.len,
+							 src_eid);
+			break;
+		default:
+			ath10k_warn("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;
+	}
+
+	if (status)
+		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc rx bad trailer", "",
+				orig_buffer, orig_length);
+
+	return status;
+}
+
+static int ath10k_htc_rx_completion_handler(struct ath10k *ar,
+					    struct sk_buff *skb,
+					    u8 pipe_id)
+{
+	int status = 0;
+	struct ath10k_htc *htc = ar->htc;
+	struct ath10k_htc_hdr *hdr;
+	struct ath10k_htc_ep *ep;
+	u16 payload_len;
+	u32 trailer_len = 0;
+	size_t min_len;
+	u8 eid;
+	bool trailer_present;
+
+	hdr = (struct ath10k_htc_hdr *)skb->data;
+	skb_pull(skb, sizeof(*hdr));
+
+	eid = hdr->eid;
+
+	if (eid >= ATH10K_HTC_EP_COUNT) {
+		ath10k_warn("HTC Rx: invalid eid %d\n", eid);
+		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc bad header", "",
+				hdr, sizeof(*hdr));
+		status = -EINVAL;
+		goto out;
+	}
+
+	ep = &htc->endpoint[eid];
+
+	/*
+	 * If this endpoint that received a message from the target has
+	 * a to-target HIF pipe whose send completions are polled rather
+	 * than interrupt-driven, this is a good point to ask HIF to check
+	 * whether it has any completed sends to handle.
+	 */
+	if (ep->ul_is_polled)
+		ath10k_htc_send_complete_check(ep, 1);
+
+	payload_len = __le16_to_cpu(hdr->len);
+
+	if (payload_len + sizeof(*hdr) > ATH10K_HTC_MAX_LEN) {
+		ath10k_warn("HTC rx frame too long, len: %zu\n",
+			    payload_len + sizeof(*hdr));
+		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc bad rx pkt len", "",
+				hdr, sizeof(*hdr));
+		status = -EINVAL;
+		goto out;
+	}
+
+	if (skb->len < payload_len) {
+		ath10k_dbg(ATH10K_DBG_HTC,
+			   "HTC Rx: insufficient length, got %d, expected %d\n",
+			   skb->len, payload_len);
+		ath10k_dbg_dump(ATH10K_DBG_HTC, "htc bad rx pkt len",
+				"", hdr, sizeof(*hdr));
+		status = -EINVAL;
+		goto out;
+	}
+
+	/* get flags to check for trailer */
+	trailer_present = hdr->flags & ATH10K_HTC_FLAG_TRAILER_PRESENT;
+	if (trailer_present) {
+		u8 *trailer;
+
+		trailer_len = hdr->trailer_len;
+		min_len = sizeof(struct ath10k_ath10k_htc_record_hdr);
+
+		if ((trailer_len < min_len) ||
+		    (trailer_len > payload_len)) {
+			ath10k_warn("Invalid trailer length: %d\n",
+				    trailer_len);
+			status = -EPROTO;
+			goto out;
+		}
+
+		trailer = (u8 *)hdr;
+		trailer += sizeof(*hdr);
+		trailer += payload_len;
+		trailer -= trailer_len;
+		status = ath10k_htc_process_trailer(htc, trailer,
+						    trailer_len, hdr->eid);
+		if (status)
+			goto out;
+
+		skb_trim(skb, skb->len - trailer_len);
+	}
+
+	if (((int)payload_len - (int)trailer_len) <= 0)
+		/* zero length packet with trailer data, just drop these */
+		goto out;
+
+	if (eid == ATH10K_HTC_EP_0) {
+		struct ath10k_htc_msg *msg = (struct ath10k_htc_msg *)skb->data;
+
+		switch (__le16_to_cpu(msg->hdr.message_id)) {
+		default:
+			/* 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
+				 */
+				ath10k_warn("HTC rx ctrl still processing\n");
+				status = -EINVAL;
+				complete(&htc->ctl_resp);
+				goto out;
+			}
+
+			htc->control_resp_len =
+				min_t(int, skb->len,
+				      ATH10K_HTC_MAX_CTRL_MSG_LEN);
+
+			memcpy(htc->control_resp_buffer, skb->data,
+			       htc->control_resp_len);
+
+			complete(&htc->ctl_resp);
+			break;
+		case ATH10K_HTC_MSG_SEND_SUSPEND_COMPLETE:
+			htc->htc_ops.target_send_suspend_complete(ar);
+		}
+		goto out;
+	}
+
+	ath10k_dbg(ATH10K_DBG_HTC, "htc rx completion ep %d skb %p\n",
+		   eid, skb);
+	ep->ep_ops.ep_rx_complete(ar, skb);
+
+	/* skb is now owned by the rx completion handler */
+	skb = NULL;
+out:
+	kfree_skb(skb);
+
+	return status;
+}
+
+static void ath10k_htc_control_rx_complete(struct ath10k *ar,
+					   struct sk_buff *skb)
+{
+	/* This is unexpected. FW is not supposed to send regular rx on this
+	 * endpoint. */
+	ath10k_warn("unexpected htc rx\n");
+	kfree_skb(skb);
+}
+
+/***************/
+/* Init/Deinit */
+/***************/
+
+static const char *htc_service_name(enum ath10k_htc_svc_id id)
+{
+	switch (id) {
+	case ATH10K_HTC_SVC_ID_RESERVED:
+		return "Reserved";
+	case ATH10K_HTC_SVC_ID_RSVD_CTRL:
+		return "Control";
+	case ATH10K_HTC_SVC_ID_WMI_CONTROL:
+		return "WMI";
+	case ATH10K_HTC_SVC_ID_WMI_DATA_BE:
+		return "DATA BE";
+	case ATH10K_HTC_SVC_ID_WMI_DATA_BK:
+		return "DATA BK";
+	case ATH10K_HTC_SVC_ID_WMI_DATA_VI:
+		return "DATA VI";
+	case ATH10K_HTC_SVC_ID_WMI_DATA_VO:
+		return "DATA VO";
+	case ATH10K_HTC_SVC_ID_NMI_CONTROL:
+		return "NMI Control";
+	case ATH10K_HTC_SVC_ID_NMI_DATA:
+		return "NMI Data";
+	case ATH10K_HTC_SVC_ID_HTT_DATA_MSG:
+		return "HTT Data";
+	case ATH10K_HTC_SVC_ID_TEST_RAW_STREAMS:
+		return "RAW";
+	}
+
+	return "Unknown";
+}
+
+static void ath10k_htc_reset_endpoint_states(struct ath10k_htc *htc)
+{
+	struct ath10k_htc_ep *ep;
+	int i;
+
+	for (i = ATH10K_HTC_EP_0; i < ATH10K_HTC_EP_COUNT; i++) {
+		ep = &htc->endpoint[i];
+		ep->service_id = ATH10K_HTC_SVC_ID_UNUSED;
+		ep->max_ep_message_len = 0;
+		ep->max_tx_queue_depth = 0;
+		ep->eid = i;
+		skb_queue_head_init(&ep->tx_queue);
+		ep->htc = htc;
+		ep->tx_credit_flow_enabled = true;
+		INIT_WORK(&ep->send_work, ath10k_htc_send_work);
+	}
+}
+
+static void ath10k_htc_setup_target_buffer_assignments(struct ath10k_htc *htc)
+{
+	struct ath10k_htc_svc_tx_credits *entry;
+
+	entry = &htc->service_tx_alloc[0];
+
+	/*
+	 * for PCIE allocate all credists/HTC buffers to WMI.
+	 * no buffers are used/required for data. data always
+	 * remains on host.
+	 */
+	entry++;
+	entry->service_id = ATH10K_HTC_SVC_ID_WMI_CONTROL;
+	entry->credit_allocation = htc->total_transmit_credits;
+}
+
+static u8 ath10k_htc_get_credit_allocation(struct ath10k_htc *htc,
+					   u16 service_id)
+{
+	u8 allocation = 0;
+	int i;
+
+	for (i = 0; i < ATH10K_HTC_EP_COUNT; i++) {
+		if (htc->service_tx_alloc[i].service_id == service_id)
+			allocation =
+			    htc->service_tx_alloc[i].credit_allocation;
+	}
+
+	return allocation;
+}
+
+int ath10k_htc_wait_target(struct ath10k_htc *htc)
+{
+	int status = 0;
+	struct ath10k_htc_svc_conn_req conn_req;
+	struct ath10k_htc_svc_conn_resp conn_resp;
+	struct ath10k_htc_msg *msg;
+	u16 message_id;
+	u16 credit_count;
+	u16 credit_size;
+
+	INIT_COMPLETION(htc->ctl_resp);
+
+	status = ath10k_hif_start(htc->ar);
+	if (status) {
+		ath10k_err("could not start HIF (%d)\n", status);
+		goto err_start;
+	}
+
+	status = wait_for_completion_timeout(&htc->ctl_resp,
+					     ATH10K_HTC_WAIT_TIMEOUT_HZ);
+	if (status <= 0) {
+		if (status == 0)
+			status = -ETIMEDOUT;
+
+		ath10k_err("ctl_resp never came in (%d)\n", status);
+		goto err_target;
+	}
+
+	if (htc->control_resp_len < sizeof(msg->hdr) + sizeof(msg->ready)) {
+		ath10k_err("Invalid HTC ready msg len:%d\n",
+			   htc->control_resp_len);
+
+		status = -ECOMM;
+		goto err_target;
+	}
+
+	msg = (struct ath10k_htc_msg *)htc->control_resp_buffer;
+	message_id   = __le16_to_cpu(msg->hdr.message_id);
+	credit_count = __le16_to_cpu(msg->ready.credit_count);
+	credit_size  = __le16_to_cpu(msg->ready.credit_size);
+
+	if (message_id != ATH10K_HTC_MSG_READY_ID) {
+		ath10k_err("Invalid HTC ready msg: 0x%x\n", message_id);
+		status = -ECOMM;
+		goto err_target;
+	}
+
+	htc->total_transmit_credits = credit_count;
+	htc->target_credit_size = credit_size;
+
+	ath10k_dbg(ATH10K_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)) {
+		status = -ECOMM;
+		ath10k_err("Invalid credit size received\n");
+		goto err_target;
+	}
+
+	ath10k_htc_setup_target_buffer_assignments(htc);
+
+	/* setup our pseudo HTC control endpoint connection */
+	memset(&conn_req, 0, sizeof(conn_req));
+	memset(&conn_resp, 0, sizeof(conn_resp));
+	conn_req.ep_ops.ep_tx_complete = ath10k_htc_control_tx_complete;
+	conn_req.ep_ops.ep_rx_complete = ath10k_htc_control_rx_complete;
+	conn_req.max_send_queue_depth = ATH10K_NUM_CONTROL_TX_BUFFERS;
+	conn_req.service_id = ATH10K_HTC_SVC_ID_RSVD_CTRL;
+
+	/* connect fake service */
+	status = ath10k_htc_connect_service(htc, &conn_req, &conn_resp);
+	if (status) {
+		ath10k_err("could not connect to htc service (%d)\n", status);
+		goto err_target;
+	}
+
+	return 0;
+err_target:
+	ath10k_hif_stop(htc->ar);
+err_start:
+	return status;
+}
+
+int ath10k_htc_connect_service(struct ath10k_htc *htc,
+			       struct ath10k_htc_svc_conn_req *conn_req,
+			       struct ath10k_htc_svc_conn_resp *conn_resp)
+{
+	struct ath10k_htc_msg *msg;
+	struct ath10k_htc_conn_svc *req_msg;
+	struct ath10k_htc_conn_svc_response resp_msg_dummy;
+	struct ath10k_htc_conn_svc_response *resp_msg = &resp_msg_dummy;
+	enum ath10k_htc_ep_id assigned_eid = ATH10K_HTC_EP_COUNT;
+	struct ath10k_htc_ep *ep;
+	struct sk_buff *skb;
+	unsigned int max_msg_size = 0;
+	int length, status;
+	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 == ATH10K_HTC_SVC_ID_RSVD_CTRL) {
+		disable_credit_flow_ctrl = true;
+		assigned_eid = ATH10K_HTC_EP_0;
+		max_msg_size = ATH10K_HTC_MAX_CTRL_MSG_LEN;
+		memset(&resp_msg_dummy, 0, sizeof(resp_msg_dummy));
+		goto setup;
+	}
+
+	tx_alloc = ath10k_htc_get_credit_allocation(htc,
+						    conn_req->service_id);
+	if (!tx_alloc)
+		ath10k_warn("HTC Service %s does not allocate target credits\n",
+			    htc_service_name(conn_req->service_id));
+
+	skb = ath10k_htc_build_tx_ctrl_skb(htc->ar);
+	if (!skb) {
+		ath10k_err("Failed to allocate HTC packet\n");
+		return -ENOMEM;
+	}
+
+	length = sizeof(msg->hdr) + sizeof(msg->connect_service);
+	skb_put(skb, length);
+	memset(skb->data, 0, length);
+
+	msg = (struct ath10k_htc_msg *)skb->data;
+	msg->hdr.message_id =
+		__cpu_to_le16(ATH10K_HTC_MSG_CONNECT_SERVICE_ID);
+
+	flags |= SM(tx_alloc, ATH10K_HTC_CONN_FLAGS_RECV_ALLOC);
+
+	req_msg = &msg->connect_service;
+	req_msg->flags = __cpu_to_le16(flags);
+	req_msg->service_id = __cpu_to_le16(conn_req->service_id);
+
+	/* Only enable credit flow control for WMI ctrl service */
+	if (conn_req->service_id != ATH10K_HTC_SVC_ID_WMI_CONTROL) {
+		flags |= ATH10K_HTC_CONN_FLAGS_DISABLE_CREDIT_FLOW_CTRL;
+		disable_credit_flow_ctrl = true;
+	}
+
+	INIT_COMPLETION(htc->ctl_resp);
+
+	status = ath10k_htc_send(htc, ATH10K_HTC_EP_0, skb);
+	if (status) {
+		kfree_skb(skb);
+		return status;
+	}
+
+	/* wait for response */
+	status = wait_for_completion_timeout(&htc->ctl_resp,
+					     ATH10K_HTC_CONN_SVC_TIMEOUT_HZ);
+	if (status <= 0) {
+		if (status == 0)
+			status = -ETIMEDOUT;
+		ath10k_err("Service connect timeout: %d\n", status);
+		return status;
+	}
+
+	/* we controlled the buffer creation, it's aligned */
+	msg = (struct ath10k_htc_msg *)htc->control_resp_buffer;
+	resp_msg = &msg->connect_service_response;
+	message_id = __le16_to_cpu(msg->hdr.message_id);
+	service_id = __le16_to_cpu(resp_msg->service_id);
+
+	if ((message_id != ATH10K_HTC_MSG_CONNECT_SERVICE_RESP_ID) ||
+	    (htc->control_resp_len < sizeof(msg->hdr) +
+	     sizeof(msg->connect_service_response))) {
+		ath10k_err("Invalid resp message ID 0x%x", message_id);
+		return -EPROTO;
+	}
+
+	ath10k_dbg(ATH10K_DBG_HTC,
+		   "HTC Service %s connect response: status: 0x%x, assigned ep: 0x%x\n",
+		   htc_service_name(service_id),
+		   resp_msg->status, resp_msg->eid);
+
+	conn_resp->connect_resp_code = resp_msg->status;
+
+	/* check response status */
+	if (resp_msg->status != ATH10K_HTC_CONN_SVC_STATUS_SUCCESS) {
+		ath10k_err("HTC Service %s connect request failed: 0x%x)\n",
+			   htc_service_name(service_id),
+			   resp_msg->status);
+		return -EPROTO;
+	}
+
+	assigned_eid = (enum ath10k_htc_ep_id)resp_msg->eid;
+	max_msg_size = __le16_to_cpu(resp_msg->max_msg_size);
+
+setup:
+
+	if (assigned_eid >= ATH10K_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 != ATH10K_HTC_SVC_ID_UNUSED)
+		return -EPROTO;
+
+	/* return assigned endpoint to caller */
+	conn_resp->eid = assigned_eid;
+	conn_resp->max_msg_len = __le16_to_cpu(resp_msg->max_msg_size);
+
+	/* 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 = __le16_to_cpu(resp_msg->max_msg_size);
+	ep->tx_credits = tx_alloc;
+	ep->tx_credit_size = htc->target_credit_size;
+	ep->tx_credits_per_max_message = ep->max_ep_message_len /
+					 htc->target_credit_size;
+
+	if (ep->max_ep_message_len % htc->target_credit_size)
+		ep->tx_credits_per_max_message++;
+
+	/* copy all the callbacks */
+	ep->ep_ops = conn_req->ep_ops;
+
+	status = ath10k_hif_map_service_to_pipe(htc->ar,
+						ep->service_id,
+						&ep->ul_pipe_id,
+						&ep->dl_pipe_id,
+						&ep->ul_is_polled,
+						&ep->dl_is_polled);
+	if (status)
+		return status;
+
+	ath10k_dbg(ATH10K_DBG_HTC,
+		   "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);
+
+	ath10k_dbg(ATH10K_DBG_HTC,
+		   "EP %d UL polled: %d, DL polled: %d\n",
+		   ep->eid, ep->ul_is_polled, ep->dl_is_polled);
+
+	if (disable_credit_flow_ctrl && ep->tx_credit_flow_enabled) {
+		ep->tx_credit_flow_enabled = false;
+		ath10k_dbg(ATH10K_DBG_HTC,
+			   "HTC service: %s eid: %d TX flow control disabled\n",
+			   htc_service_name(ep->service_id), assigned_eid);
+	}
+
+	return status;
+}
+
+struct sk_buff *ath10k_htc_alloc_skb(int size)
+{
+	struct sk_buff *skb;
+
+	skb = dev_alloc_skb(size + sizeof(struct ath10k_htc_hdr));
+	if (!skb) {
+		ath10k_warn("could not allocate HTC tx skb\n");
+		return NULL;
+	}
+
+	skb_reserve(skb, sizeof(struct ath10k_htc_hdr));
+
+	/* FW/HTC requires 4-byte aligned streams */
+	if (!IS_ALIGNED((unsigned long)skb->data, 4))
+		ath10k_warn("Unaligned HTC tx skb\n");
+
+	return skb;
+}
+
+int ath10k_htc_start(struct ath10k_htc *htc)
+{
+	struct sk_buff *skb;
+	int status = 0;
+	struct ath10k_htc_msg *msg;
+
+	skb = ath10k_htc_build_tx_ctrl_skb(htc->ar);
+	if (!skb)
+		return -ENOMEM;
+
+	skb_put(skb, sizeof(msg->hdr) + sizeof(msg->setup_complete_ext));
+	memset(skb->data, 0, skb->len);
+
+	msg = (struct ath10k_htc_msg *)skb->data;
+	msg->hdr.message_id =
+		__cpu_to_le16(ATH10K_HTC_MSG_SETUP_COMPLETE_EX_ID);
+
+	ath10k_dbg(ATH10K_DBG_HTC, "HTC is using TX credit flow control\n");
+
+	status = ath10k_htc_send(htc, ATH10K_HTC_EP_0, skb);
+	if (status) {
+		kfree_skb(skb);
+		return status;
+	}
+
+	return 0;
+}
+
+/*
+ * stop HTC communications, i.e. stop interrupt reception, and flush all
+ * queued buffers
+ */
+void ath10k_htc_stop(struct ath10k_htc *htc)
+{
+	int i;
+	struct ath10k_htc_ep *ep;
+
+	spin_lock_bh(&htc->tx_lock);
+	htc->stopping = true;
+	spin_unlock_bh(&htc->tx_lock);
+
+	for (i = ATH10K_HTC_EP_0; i < ATH10K_HTC_EP_COUNT; i++) {
+		ep = &htc->endpoint[i];
+		ath10k_htc_flush_endpoint_tx(htc, ep);
+	}
+
+	ath10k_hif_stop(htc->ar);
+	ath10k_htc_reset_endpoint_states(htc);
+}
+
+/* registered target arrival callback from the HIF layer */
+struct ath10k_htc *ath10k_htc_create(struct ath10k *ar,
+				     struct ath10k_htc_ops *htc_ops)
+{
+	struct ath10k_hif_cb htc_callbacks;
+	struct ath10k_htc_ep *ep = NULL;
+	struct ath10k_htc *htc = NULL;
+
+	/* FIXME: use struct ath10k instead */
+	htc = kzalloc(sizeof(struct ath10k_htc), GFP_KERNEL);
+	if (!htc)
+		return ERR_PTR(-ENOMEM);
+
+	spin_lock_init(&htc->tx_lock);
+
+	memcpy(&htc->htc_ops, htc_ops, sizeof(struct ath10k_htc_ops));
+
+	ath10k_htc_reset_endpoint_states(htc);
+
+	/* setup HIF layer callbacks */
+	htc_callbacks.rx_completion = ath10k_htc_rx_completion_handler;
+	htc_callbacks.tx_completion = ath10k_htc_tx_completion_handler;
+	htc->ar = ar;
+
+	/* Get HIF default pipe for HTC message exchange */
+	ep = &htc->endpoint[ATH10K_HTC_EP_0];
+
+	ath10k_hif_init(ar, &htc_callbacks);
+	ath10k_hif_get_default_pipe(ar, &ep->ul_pipe_id, &ep->dl_pipe_id);
+
+	init_completion(&htc->ctl_resp);
+
+	return htc;
+}
+
+void ath10k_htc_destroy(struct ath10k_htc *htc)
+{
+	kfree(htc);
+}