Merge tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linuxgrafted

Pull I3C updates from Alexandre Belloni:
 "A new driver this cycle, for the AMD AXI I3C controller.

  There are also new features such as IBI wakeup support, SETAASA device
  discovery and ACPI support for the the DAA methods, meaning we can now
  communicate with the SPD devices on DDR5 modules.

  New driver:
   - AMD AXI I3C master controller

  Subsystem:
   - I3C Common Command Code (CCC) handling improvements, especially
     around GET CCCs
   - SETAASA device discovery support
   - ACPI support for all existing DAA methods like SETDASA, SETNEWDA as
     well as I2C devices on I3C bus
   - IBI-based wakeup support

  Drivers:
   - dw: SETAASA support
   - mipi-i3c-hci: advertise IBI wakeup capability, AMD_PT I3C
     controller support, PIO queue management support for HCI v1.2
   - renesas: improve suspend to RAM support, add runtime PM support"

* tag 'i3c/for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/i3c/linux: (70 commits)
  i3c: dw: reduce do_daa time if there's no client
  i3c: mipi-i3c-hci: Add support for AMD_PT I3C controller
  i3c: mipi-i3c-hci: Add PIO queue management support for HCI v1.2
  i3c: mipi-i3c-hci: Fix missing STAT_IBI_STATUS_THLD in PIO mode
  i3c: dw: rename "pclk" to "apb" to match dt-binding
  i3c: dw: make struct dw_i3c_cmd smaller
  i3c: dw: use COMMAND_PORT_TRANSFER_ARG instead of hardcoding
  i3c: renesas: Don't register devices when ENTDAA times out
  i3c: master: dw-i3c-master: fix OD timing for first broadcast
  i3c: mipi-i3c-hci: Advertise IBI wakeup capability
  i3c: mipi-i3c-hci: Factor out i3c_hci_sysdev()
  i3c: mipi-i3c-hci-pci: Propagate I3C wakeup requirements to PCI
  i3c: master: Reject IBI requests from non-IBI-capable devices
  i3c: master: Add helper to query bus wakeup requirements
  i3c: master: Report wakeup events for IBIs
  i3c: master: Support IBI-based wakeup capability
  i3c: master: Fix potential UAF in i3c_device_match()
  i3c: master: Fix potential UAF in i3c_device_uevent()
  i3c: Make dev->desc locking assumptions explicit
  i3c: master: Fix use-after-free of master->this
  ...

10 files changed, 2850 insertions, 0 deletions

diff --git a/net/nfc/hci/Kconfig b/net/nfc/hci/Kconfig
new file mode 100644
index 000000000..9500b8a27
--- /dev/null
+++ b/net/nfc/hci/Kconfig
@@ -0,0 +1,18 @@
+# SPDX-License-Identifier: GPL-2.0-only
+config NFC_HCI
+	depends on NFC
+	tristate "NFC HCI implementation"
+	default n
+	help
+	  Say Y here if you want to build support for a kernel NFC HCI
+	  implementation. This is mostly needed for devices that only process
+	  HCI frames, like for example the NXP pn544.
+
+config NFC_SHDLC
+	depends on NFC_HCI
+	select CRC_CCITT
+	bool "SHDLC link layer for HCI based NFC drivers"
+	default n
+	help
+	  Say yes if you use an NFC HCI driver that requires SHDLC link layer.
+	  If unsure, say N here.
diff --git a/net/nfc/hci/Makefile b/net/nfc/hci/Makefile
new file mode 100644
index 000000000..5a0aaae6f
--- /dev/null
+++ b/net/nfc/hci/Makefile
@@ -0,0 +1,9 @@
+# SPDX-License-Identifier: GPL-2.0-only
+#
+# Makefile for the Linux NFC HCI layer.
+#
+
+obj-$(CONFIG_NFC_HCI) += hci.o
+
+hci-y			:= core.o hcp.o command.o llc.o llc_nop.o
+hci-$(CONFIG_NFC_SHDLC) += llc_shdlc.o
diff --git a/net/nfc/hci/command.c b/net/nfc/hci/command.c
new file mode 100644
index 000000000..af6bacb3b
--- /dev/null
+++ b/net/nfc/hci/command.c
@@ -0,0 +1,344 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "hci: %s: " fmt, __func__
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/sched.h>
+#include <linux/module.h>
+
+#include <net/nfc/hci.h>
+
+#include "hci.h"
+
+#define MAX_FWI 4949
+
+static int nfc_hci_execute_cmd_async(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
+			       const u8 *param, size_t param_len,
+			       data_exchange_cb_t cb, void *cb_context)
+{
+	pr_debug("exec cmd async through pipe=%d, cmd=%d, plen=%zd\n", pipe,
+		 cmd, param_len);
+
+	/* TODO: Define hci cmd execution delay. Should it be the same
+	 * for all commands?
+	 */
+	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_COMMAND, cmd,
+				      param, param_len, cb, cb_context, MAX_FWI);
+}
+
+/*
+ * HCI command execution completion callback.
+ * err will be a standard linux error (may be converted from HCI response)
+ * skb contains the response data and must be disposed, or may be NULL if
+ * an error occurred
+ */
+static void nfc_hci_execute_cb(void *context, struct sk_buff *skb, int err)
+{
+	struct hcp_exec_waiter *hcp_ew = (struct hcp_exec_waiter *)context;
+
+	pr_debug("HCI Cmd completed with result=%d\n", err);
+
+	hcp_ew->exec_result = err;
+	if (hcp_ew->exec_result == 0)
+		hcp_ew->result_skb = skb;
+	else
+		kfree_skb(skb);
+	hcp_ew->exec_complete = true;
+
+	wake_up(hcp_ew->wq);
+}
+
+static int nfc_hci_execute_cmd(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
+			       const u8 *param, size_t param_len,
+			       struct sk_buff **skb)
+{
+	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(ew_wq);
+	struct hcp_exec_waiter hcp_ew;
+	hcp_ew.wq = &ew_wq;
+	hcp_ew.exec_complete = false;
+	hcp_ew.result_skb = NULL;
+
+	pr_debug("exec cmd sync through pipe=%d, cmd=%d, plen=%zd\n", pipe,
+		 cmd, param_len);
+
+	/* TODO: Define hci cmd execution delay. Should it be the same
+	 * for all commands?
+	 */
+	hcp_ew.exec_result = nfc_hci_hcp_message_tx(hdev, pipe,
+						    NFC_HCI_HCP_COMMAND, cmd,
+						    param, param_len,
+						    nfc_hci_execute_cb, &hcp_ew,
+						    MAX_FWI);
+	if (hcp_ew.exec_result < 0)
+		return hcp_ew.exec_result;
+
+	wait_event(ew_wq, hcp_ew.exec_complete == true);
+
+	if (hcp_ew.exec_result == 0) {
+		if (skb)
+			*skb = hcp_ew.result_skb;
+		else
+			kfree_skb(hcp_ew.result_skb);
+	}
+
+	return hcp_ew.exec_result;
+}
+
+int nfc_hci_send_event(struct nfc_hci_dev *hdev, u8 gate, u8 event,
+		       const u8 *param, size_t param_len)
+{
+	u8 pipe;
+
+	pr_debug("%d to gate %d\n", event, gate);
+
+	pipe = hdev->gate2pipe[gate];
+	if (pipe == NFC_HCI_INVALID_PIPE)
+		return -EADDRNOTAVAIL;
+
+	return nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_EVENT, event,
+				      param, param_len, NULL, NULL, 0);
+}
+EXPORT_SYMBOL(nfc_hci_send_event);
+
+/*
+ * Execute an hci command sent to gate.
+ * skb will contain response data if success. skb can be NULL if you are not
+ * interested by the response.
+ */
+int nfc_hci_send_cmd(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
+		     const u8 *param, size_t param_len, struct sk_buff **skb)
+{
+	u8 pipe;
+
+	pipe = hdev->gate2pipe[gate];
+	if (pipe == NFC_HCI_INVALID_PIPE)
+		return -EADDRNOTAVAIL;
+
+	return nfc_hci_execute_cmd(hdev, pipe, cmd, param, param_len, skb);
+}
+EXPORT_SYMBOL(nfc_hci_send_cmd);
+
+int nfc_hci_send_cmd_async(struct nfc_hci_dev *hdev, u8 gate, u8 cmd,
+			   const u8 *param, size_t param_len,
+			   data_exchange_cb_t cb, void *cb_context)
+{
+	u8 pipe;
+
+	pipe = hdev->gate2pipe[gate];
+	if (pipe == NFC_HCI_INVALID_PIPE)
+		return -EADDRNOTAVAIL;
+
+	return nfc_hci_execute_cmd_async(hdev, pipe, cmd, param, param_len,
+					 cb, cb_context);
+}
+EXPORT_SYMBOL(nfc_hci_send_cmd_async);
+
+int nfc_hci_set_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
+		      const u8 *param, size_t param_len)
+{
+	int r;
+	u8 *tmp;
+
+	/* TODO ELa: reg idx must be inserted before param, but we don't want
+	 * to ask the caller to do it to keep a simpler API.
+	 * For now, just create a new temporary param buffer. This is far from
+	 * optimal though, and the plan is to modify APIs to pass idx down to
+	 * nfc_hci_hcp_message_tx where the frame is actually built, thereby
+	 * eliminating the need for the temp allocation-copy here.
+	 */
+
+	pr_debug("idx=%d to gate %d\n", idx, gate);
+
+	tmp = kmalloc(1 + param_len, GFP_KERNEL);
+	if (tmp == NULL)
+		return -ENOMEM;
+
+	*tmp = idx;
+	memcpy(tmp + 1, param, param_len);
+
+	r = nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_SET_PARAMETER,
+			     tmp, param_len + 1, NULL);
+
+	kfree(tmp);
+
+	return r;
+}
+EXPORT_SYMBOL(nfc_hci_set_param);
+
+int nfc_hci_get_param(struct nfc_hci_dev *hdev, u8 gate, u8 idx,
+		      struct sk_buff **skb)
+{
+	pr_debug("gate=%d regidx=%d\n", gate, idx);
+
+	return nfc_hci_send_cmd(hdev, gate, NFC_HCI_ANY_GET_PARAMETER,
+				&idx, 1, skb);
+}
+EXPORT_SYMBOL(nfc_hci_get_param);
+
+static int nfc_hci_open_pipe(struct nfc_hci_dev *hdev, u8 pipe)
+{
+	struct sk_buff *skb;
+	int r;
+
+	pr_debug("pipe=%d\n", pipe);
+
+	r = nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_OPEN_PIPE,
+				NULL, 0, &skb);
+	if (r == 0) {
+		/* dest host other than host controller will send
+		 * number of pipes already open on this gate before
+		 * execution. The number can be found in skb->data[0]
+		 */
+		kfree_skb(skb);
+	}
+
+	return r;
+}
+
+static int nfc_hci_close_pipe(struct nfc_hci_dev *hdev, u8 pipe)
+{
+	return nfc_hci_execute_cmd(hdev, pipe, NFC_HCI_ANY_CLOSE_PIPE,
+				   NULL, 0, NULL);
+}
+
+static u8 nfc_hci_create_pipe(struct nfc_hci_dev *hdev, u8 dest_host,
+			      u8 dest_gate, int *result)
+{
+	struct sk_buff *skb;
+	struct hci_create_pipe_params params;
+	struct hci_create_pipe_resp *resp;
+	u8 pipe;
+
+	pr_debug("gate=%d\n", dest_gate);
+
+	params.src_gate = NFC_HCI_ADMIN_GATE;
+	params.dest_host = dest_host;
+	params.dest_gate = dest_gate;
+
+	*result = nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
+				      NFC_HCI_ADM_CREATE_PIPE,
+				      (u8 *) &params, sizeof(params), &skb);
+	if (*result < 0)
+		return NFC_HCI_INVALID_PIPE;
+
+	resp = (struct hci_create_pipe_resp *)skb->data;
+	pipe = resp->pipe;
+	kfree_skb(skb);
+
+	pr_debug("pipe created=%d\n", pipe);
+
+	return pipe;
+}
+
+static int nfc_hci_delete_pipe(struct nfc_hci_dev *hdev, u8 pipe)
+{
+	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
+				   NFC_HCI_ADM_DELETE_PIPE, &pipe, 1, NULL);
+}
+
+static int nfc_hci_clear_all_pipes(struct nfc_hci_dev *hdev)
+{
+	u8 param[2];
+	size_t param_len = 2;
+
+	/* TODO: Find out what the identity reference data is
+	 * and fill param with it. HCI spec 6.1.3.5 */
+
+	if (test_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &hdev->quirks))
+		param_len = 0;
+
+	return nfc_hci_execute_cmd(hdev, NFC_HCI_ADMIN_PIPE,
+				   NFC_HCI_ADM_CLEAR_ALL_PIPE, param, param_len,
+				   NULL);
+}
+
+int nfc_hci_disconnect_gate(struct nfc_hci_dev *hdev, u8 gate)
+{
+	int r;
+	u8 pipe = hdev->gate2pipe[gate];
+
+	if (pipe == NFC_HCI_INVALID_PIPE)
+		return -EADDRNOTAVAIL;
+
+	r = nfc_hci_close_pipe(hdev, pipe);
+	if (r < 0)
+		return r;
+
+	if (pipe != NFC_HCI_LINK_MGMT_PIPE && pipe != NFC_HCI_ADMIN_PIPE) {
+		r = nfc_hci_delete_pipe(hdev, pipe);
+		if (r < 0)
+			return r;
+	}
+
+	hdev->gate2pipe[gate] = NFC_HCI_INVALID_PIPE;
+
+	return 0;
+}
+EXPORT_SYMBOL(nfc_hci_disconnect_gate);
+
+int nfc_hci_disconnect_all_gates(struct nfc_hci_dev *hdev)
+{
+	int r;
+
+	r = nfc_hci_clear_all_pipes(hdev);
+	if (r < 0)
+		return r;
+
+	nfc_hci_reset_pipes(hdev);
+
+	return 0;
+}
+EXPORT_SYMBOL(nfc_hci_disconnect_all_gates);
+
+int nfc_hci_connect_gate(struct nfc_hci_dev *hdev, u8 dest_host, u8 dest_gate,
+			 u8 pipe)
+{
+	bool pipe_created = false;
+	int r;
+
+	if (pipe == NFC_HCI_DO_NOT_CREATE_PIPE)
+		return 0;
+
+	if (hdev->gate2pipe[dest_gate] != NFC_HCI_INVALID_PIPE)
+		return -EADDRINUSE;
+
+	if (pipe != NFC_HCI_INVALID_PIPE)
+		goto open_pipe;
+
+	switch (dest_gate) {
+	case NFC_HCI_LINK_MGMT_GATE:
+		pipe = NFC_HCI_LINK_MGMT_PIPE;
+		break;
+	case NFC_HCI_ADMIN_GATE:
+		pipe = NFC_HCI_ADMIN_PIPE;
+		break;
+	default:
+		pipe = nfc_hci_create_pipe(hdev, dest_host, dest_gate, &r);
+		if (pipe == NFC_HCI_INVALID_PIPE)
+			return r;
+		pipe_created = true;
+		break;
+	}
+
+open_pipe:
+	r = nfc_hci_open_pipe(hdev, pipe);
+	if (r < 0) {
+		if (pipe_created)
+			if (nfc_hci_delete_pipe(hdev, pipe) < 0) {
+				/* TODO: Cannot clean by deleting pipe...
+				 * -> inconsistent state */
+			}
+		return r;
+	}
+
+	hdev->pipes[pipe].gate = dest_gate;
+	hdev->pipes[pipe].dest_host = dest_host;
+	hdev->gate2pipe[dest_gate] = pipe;
+
+	return 0;
+}
+EXPORT_SYMBOL(nfc_hci_connect_gate);
diff --git a/net/nfc/hci/core.c b/net/nfc/hci/core.c
new file mode 100644
index 000000000..ba6f0310f
--- /dev/null
+++ b/net/nfc/hci/core.c
@@ -0,0 +1,1115 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "hci: %s: " fmt, __func__
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/nfc.h>
+
+#include <net/nfc/nfc.h>
+#include <net/nfc/hci.h>
+#include <net/nfc/llc.h>
+
+#include "hci.h"
+
+/* Largest headroom needed for outgoing HCI commands */
+#define HCI_CMDS_HEADROOM 1
+
+int nfc_hci_result_to_errno(u8 result)
+{
+	switch (result) {
+	case NFC_HCI_ANY_OK:
+		return 0;
+	case NFC_HCI_ANY_E_REG_PAR_UNKNOWN:
+		return -EOPNOTSUPP;
+	case NFC_HCI_ANY_E_TIMEOUT:
+		return -ETIME;
+	default:
+		return -1;
+	}
+}
+EXPORT_SYMBOL(nfc_hci_result_to_errno);
+
+void nfc_hci_reset_pipes(struct nfc_hci_dev *hdev)
+{
+	int i = 0;
+
+	for (i = 0; i < NFC_HCI_MAX_PIPES; i++) {
+		hdev->pipes[i].gate = NFC_HCI_INVALID_GATE;
+		hdev->pipes[i].dest_host = NFC_HCI_INVALID_HOST;
+	}
+	memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
+}
+EXPORT_SYMBOL(nfc_hci_reset_pipes);
+
+void nfc_hci_reset_pipes_per_host(struct nfc_hci_dev *hdev, u8 host)
+{
+	int i = 0;
+
+	for (i = 0; i < NFC_HCI_MAX_PIPES; i++) {
+		if (hdev->pipes[i].dest_host != host)
+			continue;
+
+		hdev->pipes[i].gate = NFC_HCI_INVALID_GATE;
+		hdev->pipes[i].dest_host = NFC_HCI_INVALID_HOST;
+	}
+}
+EXPORT_SYMBOL(nfc_hci_reset_pipes_per_host);
+
+static void nfc_hci_msg_tx_work(struct work_struct *work)
+{
+	struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
+						msg_tx_work);
+	struct hci_msg *msg;
+	struct sk_buff *skb;
+	int r = 0;
+
+	mutex_lock(&hdev->msg_tx_mutex);
+	if (hdev->shutting_down)
+		goto exit;
+
+	if (hdev->cmd_pending_msg) {
+		if (timer_pending(&hdev->cmd_timer) == 0) {
+			if (hdev->cmd_pending_msg->cb)
+				hdev->cmd_pending_msg->cb(hdev->
+							  cmd_pending_msg->
+							  cb_context,
+							  NULL,
+							  -ETIME);
+			kfree(hdev->cmd_pending_msg);
+			hdev->cmd_pending_msg = NULL;
+		} else {
+			goto exit;
+		}
+	}
+
+next_msg:
+	if (list_empty(&hdev->msg_tx_queue))
+		goto exit;
+
+	msg = list_first_entry(&hdev->msg_tx_queue, struct hci_msg, msg_l);
+	list_del(&msg->msg_l);
+
+	pr_debug("msg_tx_queue has a cmd to send\n");
+	while ((skb = skb_dequeue(&msg->msg_frags)) != NULL) {
+		r = nfc_llc_xmit_from_hci(hdev->llc, skb);
+		if (r < 0) {
+			kfree_skb(skb);
+			skb_queue_purge(&msg->msg_frags);
+			if (msg->cb)
+				msg->cb(msg->cb_context, NULL, r);
+			kfree(msg);
+			break;
+		}
+	}
+
+	if (r)
+		goto next_msg;
+
+	if (msg->wait_response == false) {
+		kfree(msg);
+		goto next_msg;
+	}
+
+	hdev->cmd_pending_msg = msg;
+	mod_timer(&hdev->cmd_timer, jiffies +
+		  msecs_to_jiffies(hdev->cmd_pending_msg->completion_delay));
+
+exit:
+	mutex_unlock(&hdev->msg_tx_mutex);
+}
+
+static void nfc_hci_msg_rx_work(struct work_struct *work)
+{
+	struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
+						msg_rx_work);
+	struct sk_buff *skb;
+	const struct hcp_message *message;
+	u8 pipe;
+	u8 type;
+	u8 instruction;
+
+	while ((skb = skb_dequeue(&hdev->msg_rx_queue)) != NULL) {
+		pipe = skb->data[0];
+		skb_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN);
+		message = (struct hcp_message *)skb->data;
+		type = HCP_MSG_GET_TYPE(message->header);
+		instruction = HCP_MSG_GET_CMD(message->header);
+		skb_pull(skb, NFC_HCI_HCP_MESSAGE_HEADER_LEN);
+
+		nfc_hci_hcp_message_rx(hdev, pipe, type, instruction, skb);
+	}
+}
+
+static void __nfc_hci_cmd_completion(struct nfc_hci_dev *hdev, int err,
+				     struct sk_buff *skb)
+{
+	timer_delete_sync(&hdev->cmd_timer);
+
+	if (hdev->cmd_pending_msg->cb)
+		hdev->cmd_pending_msg->cb(hdev->cmd_pending_msg->cb_context,
+					  skb, err);
+	else
+		kfree_skb(skb);
+
+	kfree(hdev->cmd_pending_msg);
+	hdev->cmd_pending_msg = NULL;
+
+	schedule_work(&hdev->msg_tx_work);
+}
+
+void nfc_hci_resp_received(struct nfc_hci_dev *hdev, u8 result,
+			   struct sk_buff *skb)
+{
+	mutex_lock(&hdev->msg_tx_mutex);
+
+	if (hdev->cmd_pending_msg == NULL) {
+		kfree_skb(skb);
+		goto exit;
+	}
+
+	__nfc_hci_cmd_completion(hdev, nfc_hci_result_to_errno(result), skb);
+
+exit:
+	mutex_unlock(&hdev->msg_tx_mutex);
+}
+
+void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
+			  struct sk_buff *skb)
+{
+	u8 status = NFC_HCI_ANY_OK;
+	const struct hci_create_pipe_resp *create_info;
+	const struct hci_delete_pipe_noti *delete_info;
+	const struct hci_all_pipe_cleared_noti *cleared_info;
+	u8 gate;
+
+	pr_debug("from pipe %x cmd %x\n", pipe, cmd);
+
+	if (pipe >= NFC_HCI_MAX_PIPES) {
+		status = NFC_HCI_ANY_E_NOK;
+		goto exit;
+	}
+
+	gate = hdev->pipes[pipe].gate;
+
+	switch (cmd) {
+	case NFC_HCI_ADM_NOTIFY_PIPE_CREATED:
+		if (skb->len != 5) {
+			status = NFC_HCI_ANY_E_NOK;
+			goto exit;
+		}
+		create_info = (struct hci_create_pipe_resp *)skb->data;
+
+		if (create_info->pipe >= NFC_HCI_MAX_PIPES) {
+			status = NFC_HCI_ANY_E_NOK;
+			goto exit;
+		}
+
+		/* Save the new created pipe and bind with local gate,
+		 * the description for skb->data[3] is destination gate id
+		 * but since we received this cmd from host controller, we
+		 * are the destination and it is our local gate
+		 */
+		hdev->gate2pipe[create_info->dest_gate] = create_info->pipe;
+		hdev->pipes[create_info->pipe].gate = create_info->dest_gate;
+		hdev->pipes[create_info->pipe].dest_host =
+							create_info->src_host;
+		break;
+	case NFC_HCI_ANY_OPEN_PIPE:
+		if (gate == NFC_HCI_INVALID_GATE) {
+			status = NFC_HCI_ANY_E_NOK;
+			goto exit;
+		}
+		break;
+	case NFC_HCI_ADM_NOTIFY_PIPE_DELETED:
+		if (skb->len != 1) {
+			status = NFC_HCI_ANY_E_NOK;
+			goto exit;
+		}
+		delete_info = (struct hci_delete_pipe_noti *)skb->data;
+
+		if (delete_info->pipe >= NFC_HCI_MAX_PIPES) {
+			status = NFC_HCI_ANY_E_NOK;
+			goto exit;
+		}
+
+		hdev->pipes[delete_info->pipe].gate = NFC_HCI_INVALID_GATE;
+		hdev->pipes[delete_info->pipe].dest_host = NFC_HCI_INVALID_HOST;
+		break;
+	case NFC_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED:
+		if (skb->len != 1) {
+			status = NFC_HCI_ANY_E_NOK;
+			goto exit;
+		}
+		cleared_info = (struct hci_all_pipe_cleared_noti *)skb->data;
+
+		nfc_hci_reset_pipes_per_host(hdev, cleared_info->host);
+		break;
+	default:
+		pr_info("Discarded unknown cmd %x to gate %x\n", cmd, gate);
+		break;
+	}
+
+	if (hdev->ops->cmd_received)
+		hdev->ops->cmd_received(hdev, pipe, cmd, skb);
+
+exit:
+	nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,
+			       status, NULL, 0, NULL, NULL, 0);
+
+	kfree_skb(skb);
+}
+
+u32 nfc_hci_sak_to_protocol(u8 sak)
+{
+	switch (NFC_HCI_TYPE_A_SEL_PROT(sak)) {
+	case NFC_HCI_TYPE_A_SEL_PROT_MIFARE:
+		return NFC_PROTO_MIFARE_MASK;
+	case NFC_HCI_TYPE_A_SEL_PROT_ISO14443:
+		return NFC_PROTO_ISO14443_MASK;
+	case NFC_HCI_TYPE_A_SEL_PROT_DEP:
+		return NFC_PROTO_NFC_DEP_MASK;
+	case NFC_HCI_TYPE_A_SEL_PROT_ISO14443_DEP:
+		return NFC_PROTO_ISO14443_MASK | NFC_PROTO_NFC_DEP_MASK;
+	default:
+		return 0xffffffff;
+	}
+}
+EXPORT_SYMBOL(nfc_hci_sak_to_protocol);
+
+int nfc_hci_target_discovered(struct nfc_hci_dev *hdev, u8 gate)
+{
+	struct nfc_target *targets;
+	struct sk_buff *atqa_skb = NULL;
+	struct sk_buff *sak_skb = NULL;
+	struct sk_buff *uid_skb = NULL;
+	int r;
+
+	pr_debug("from gate %d\n", gate);
+
+	targets = kzalloc_obj(struct nfc_target);
+	if (targets == NULL)
+		return -ENOMEM;
+
+	switch (gate) {
+	case NFC_HCI_RF_READER_A_GATE:
+		r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
+				      NFC_HCI_RF_READER_A_ATQA, &atqa_skb);
+		if (r < 0)
+			goto exit;
+
+		r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
+				      NFC_HCI_RF_READER_A_SAK, &sak_skb);
+		if (r < 0)
+			goto exit;
+
+		if (atqa_skb->len != 2 || sak_skb->len != 1) {
+			r = -EPROTO;
+			goto exit;
+		}
+
+		targets->supported_protocols =
+				nfc_hci_sak_to_protocol(sak_skb->data[0]);
+		if (targets->supported_protocols == 0xffffffff) {
+			r = -EPROTO;
+			goto exit;
+		}
+
+		targets->sens_res = be16_to_cpu(*(__be16 *)atqa_skb->data);
+		targets->sel_res = sak_skb->data[0];
+
+		r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
+				      NFC_HCI_RF_READER_A_UID, &uid_skb);
+		if (r < 0)
+			goto exit;
+
+		if (uid_skb->len == 0 || uid_skb->len > NFC_NFCID1_MAXSIZE) {
+			r = -EPROTO;
+			goto exit;
+		}
+
+		memcpy(targets->nfcid1, uid_skb->data, uid_skb->len);
+		targets->nfcid1_len = uid_skb->len;
+
+		if (hdev->ops->complete_target_discovered) {
+			r = hdev->ops->complete_target_discovered(hdev, gate,
+								  targets);
+			if (r < 0)
+				goto exit;
+		}
+		break;
+	case NFC_HCI_RF_READER_B_GATE:
+		targets->supported_protocols = NFC_PROTO_ISO14443_B_MASK;
+		break;
+	default:
+		if (hdev->ops->target_from_gate)
+			r = hdev->ops->target_from_gate(hdev, gate, targets);
+		else
+			r = -EPROTO;
+		if (r < 0)
+			goto exit;
+
+		if (hdev->ops->complete_target_discovered) {
+			r = hdev->ops->complete_target_discovered(hdev, gate,
+								  targets);
+			if (r < 0)
+				goto exit;
+		}
+		break;
+	}
+
+	/* if driver set the new gate, we will skip the old one */
+	if (targets->hci_reader_gate == 0x00)
+		targets->hci_reader_gate = gate;
+
+	r = nfc_targets_found(hdev->ndev, targets, 1);
+
+exit:
+	kfree(targets);
+	kfree_skb(atqa_skb);
+	kfree_skb(sak_skb);
+	kfree_skb(uid_skb);
+
+	return r;
+}
+EXPORT_SYMBOL(nfc_hci_target_discovered);
+
+void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,
+			    struct sk_buff *skb)
+{
+	int r = 0;
+	u8 gate;
+
+	if (pipe >= NFC_HCI_MAX_PIPES) {
+		pr_err("Discarded event %x to invalid pipe %x\n", event, pipe);
+		goto exit;
+	}
+
+	gate = hdev->pipes[pipe].gate;
+	if (gate == NFC_HCI_INVALID_GATE) {
+		pr_err("Discarded event %x to unopened pipe %x\n", event, pipe);
+		goto exit;
+	}
+
+	if (hdev->ops->event_received) {
+		r = hdev->ops->event_received(hdev, pipe, event, skb);
+		if (r <= 0)
+			goto exit_noskb;
+	}
+
+	switch (event) {
+	case NFC_HCI_EVT_TARGET_DISCOVERED:
+		if (skb->len < 1) {	/* no status data? */
+			r = -EPROTO;
+			goto exit;
+		}
+
+		if (skb->data[0] == 3) {
+			/* TODO: Multiple targets in field, none activated
+			 * poll is supposedly stopped, but there is no
+			 * single target to activate, so nothing to report
+			 * up.
+			 * if we need to restart poll, we must save the
+			 * protocols from the initial poll and reuse here.
+			 */
+		}
+
+		if (skb->data[0] != 0) {
+			r = -EPROTO;
+			goto exit;
+		}
+
+		r = nfc_hci_target_discovered(hdev, gate);
+		break;
+	default:
+		pr_info("Discarded unknown event %x to gate %x\n", event, gate);
+		r = -EINVAL;
+		break;
+	}
+
+exit:
+	kfree_skb(skb);
+
+exit_noskb:
+	if (r)
+		nfc_hci_driver_failure(hdev, r);
+}
+
+static void nfc_hci_cmd_timeout(struct timer_list *t)
+{
+	struct nfc_hci_dev *hdev = timer_container_of(hdev, t, cmd_timer);
+
+	schedule_work(&hdev->msg_tx_work);
+}
+
+static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,
+				 const struct nfc_hci_gate *gates)
+{
+	int r;
+	while (gate_count--) {
+		r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
+					 gates->gate, gates->pipe);
+		if (r < 0)
+			return r;
+		gates++;
+	}
+
+	return 0;
+}
+
+static int hci_dev_session_init(struct nfc_hci_dev *hdev)
+{
+	struct sk_buff *skb = NULL;
+	int r;
+
+	if (hdev->init_data.gates[0].gate != NFC_HCI_ADMIN_GATE)
+		return -EPROTO;
+
+	r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
+				 hdev->init_data.gates[0].gate,
+				 hdev->init_data.gates[0].pipe);
+	if (r < 0)
+		goto exit;
+
+	r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
+			      NFC_HCI_ADMIN_SESSION_IDENTITY, &skb);
+	if (r < 0)
+		goto disconnect_all;
+
+	if (skb->len && skb->len == strlen(hdev->init_data.session_id) &&
+		(memcmp(hdev->init_data.session_id, skb->data,
+			   skb->len) == 0) && hdev->ops->load_session) {
+		/* Restore gate<->pipe table from some proprietary location. */
+
+		r = hdev->ops->load_session(hdev);
+
+		if (r < 0)
+			goto disconnect_all;
+	} else {
+
+		r = nfc_hci_disconnect_all_gates(hdev);
+		if (r < 0)
+			goto exit;
+
+		r = hci_dev_connect_gates(hdev, hdev->init_data.gate_count,
+					  hdev->init_data.gates);
+		if (r < 0)
+			goto disconnect_all;
+
+		r = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,
+				NFC_HCI_ADMIN_SESSION_IDENTITY,
+				hdev->init_data.session_id,
+				strlen(hdev->init_data.session_id));
+	}
+	if (r == 0)
+		goto exit;
+
+disconnect_all:
+	nfc_hci_disconnect_all_gates(hdev);
+
+exit:
+	kfree_skb(skb);
+
+	return r;
+}
+
+static int hci_dev_version(struct nfc_hci_dev *hdev)
+{
+	int r;
+	struct sk_buff *skb;
+
+	r = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,
+			      NFC_HCI_ID_MGMT_VERSION_SW, &skb);
+	if (r == -EOPNOTSUPP) {
+		pr_info("Software/Hardware info not available\n");
+		return 0;
+	}
+	if (r < 0)
+		return r;
+
+	if (skb->len != 3) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	hdev->sw_romlib = (skb->data[0] & 0xf0) >> 4;
+	hdev->sw_patch = skb->data[0] & 0x0f;
+	hdev->sw_flashlib_major = skb->data[1];
+	hdev->sw_flashlib_minor = skb->data[2];
+
+	kfree_skb(skb);
+
+	r = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,
+			      NFC_HCI_ID_MGMT_VERSION_HW, &skb);
+	if (r < 0)
+		return r;
+
+	if (skb->len != 3) {
+		kfree_skb(skb);
+		return -EINVAL;
+	}
+
+	hdev->hw_derivative = (skb->data[0] & 0xe0) >> 5;
+	hdev->hw_version = skb->data[0] & 0x1f;
+	hdev->hw_mpw = (skb->data[1] & 0xc0) >> 6;
+	hdev->hw_software = skb->data[1] & 0x3f;
+	hdev->hw_bsid = skb->data[2];
+
+	kfree_skb(skb);
+
+	pr_info("SOFTWARE INFO:\n");
+	pr_info("RomLib         : %d\n", hdev->sw_romlib);
+	pr_info("Patch          : %d\n", hdev->sw_patch);
+	pr_info("FlashLib Major : %d\n", hdev->sw_flashlib_major);
+	pr_info("FlashLib Minor : %d\n", hdev->sw_flashlib_minor);
+	pr_info("HARDWARE INFO:\n");
+	pr_info("Derivative     : %d\n", hdev->hw_derivative);
+	pr_info("HW Version     : %d\n", hdev->hw_version);
+	pr_info("#MPW           : %d\n", hdev->hw_mpw);
+	pr_info("Software       : %d\n", hdev->hw_software);
+	pr_info("BSID Version   : %d\n", hdev->hw_bsid);
+
+	return 0;
+}
+
+static int hci_dev_up(struct nfc_dev *nfc_dev)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+	int r = 0;
+
+	if (hdev->ops->open) {
+		r = hdev->ops->open(hdev);
+		if (r < 0)
+			return r;
+	}
+
+	r = nfc_llc_start(hdev->llc);
+	if (r < 0)
+		goto exit_close;
+
+	r = hci_dev_session_init(hdev);
+	if (r < 0)
+		goto exit_llc;
+
+	r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
+			       NFC_HCI_EVT_END_OPERATION, NULL, 0);
+	if (r < 0)
+		goto exit_llc;
+
+	if (hdev->ops->hci_ready) {
+		r = hdev->ops->hci_ready(hdev);
+		if (r < 0)
+			goto exit_llc;
+	}
+
+	r = hci_dev_version(hdev);
+	if (r < 0)
+		goto exit_llc;
+
+	return 0;
+
+exit_llc:
+	nfc_llc_stop(hdev->llc);
+
+exit_close:
+	if (hdev->ops->close)
+		hdev->ops->close(hdev);
+
+	return r;
+}
+
+static int hci_dev_down(struct nfc_dev *nfc_dev)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	nfc_llc_stop(hdev->llc);
+
+	if (hdev->ops->close)
+		hdev->ops->close(hdev);
+
+	nfc_hci_reset_pipes(hdev);
+
+	return 0;
+}
+
+static int hci_start_poll(struct nfc_dev *nfc_dev,
+			  u32 im_protocols, u32 tm_protocols)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (hdev->ops->start_poll)
+		return hdev->ops->start_poll(hdev, im_protocols, tm_protocols);
+	else
+		return nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
+					  NFC_HCI_EVT_READER_REQUESTED,
+					  NULL, 0);
+}
+
+static void hci_stop_poll(struct nfc_dev *nfc_dev)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (hdev->ops->stop_poll)
+		hdev->ops->stop_poll(hdev);
+	else
+		nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
+				   NFC_HCI_EVT_END_OPERATION, NULL, 0);
+}
+
+static int hci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
+				__u8 comm_mode, __u8 *gb, size_t gb_len)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (!hdev->ops->dep_link_up)
+		return 0;
+
+	return hdev->ops->dep_link_up(hdev, target, comm_mode,
+				      gb, gb_len);
+}
+
+static int hci_dep_link_down(struct nfc_dev *nfc_dev)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (!hdev->ops->dep_link_down)
+		return 0;
+
+	return hdev->ops->dep_link_down(hdev);
+}
+
+static int hci_activate_target(struct nfc_dev *nfc_dev,
+			       struct nfc_target *target, u32 protocol)
+{
+	return 0;
+}
+
+static void hci_deactivate_target(struct nfc_dev *nfc_dev,
+				  struct nfc_target *target,
+				  u8 mode)
+{
+}
+
+#define HCI_CB_TYPE_TRANSCEIVE 1
+
+static void hci_transceive_cb(void *context, struct sk_buff *skb, int err)
+{
+	struct nfc_hci_dev *hdev = context;
+
+	switch (hdev->async_cb_type) {
+	case HCI_CB_TYPE_TRANSCEIVE:
+		/*
+		 * TODO: Check RF Error indicator to make sure data is valid.
+		 * It seems that HCI cmd can complete without error, but data
+		 * can be invalid if an RF error occurred? Ignore for now.
+		 */
+		if (err == 0)
+			skb_trim(skb, skb->len - 1); /* RF Err ind */
+
+		hdev->async_cb(hdev->async_cb_context, skb, err);
+		break;
+	default:
+		if (err == 0)
+			kfree_skb(skb);
+		break;
+	}
+}
+
+static int hci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
+			  struct sk_buff *skb, data_exchange_cb_t cb,
+			  void *cb_context)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+	int r;
+
+	pr_debug("target_idx=%d\n", target->idx);
+
+	switch (target->hci_reader_gate) {
+	case NFC_HCI_RF_READER_A_GATE:
+	case NFC_HCI_RF_READER_B_GATE:
+		if (hdev->ops->im_transceive) {
+			r = hdev->ops->im_transceive(hdev, target, skb, cb,
+						     cb_context);
+			if (r <= 0)	/* handled */
+				break;
+		}
+
+		*(u8 *)skb_push(skb, 1) = 0;	/* CTR, see spec:10.2.2.1 */
+
+		hdev->async_cb_type = HCI_CB_TYPE_TRANSCEIVE;
+		hdev->async_cb = cb;
+		hdev->async_cb_context = cb_context;
+
+		r = nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
+					   NFC_HCI_WR_XCHG_DATA, skb->data,
+					   skb->len, hci_transceive_cb, hdev);
+		break;
+	default:
+		if (hdev->ops->im_transceive) {
+			r = hdev->ops->im_transceive(hdev, target, skb, cb,
+						     cb_context);
+			if (r == 1)
+				r = -ENOTSUPP;
+		} else {
+			r = -ENOTSUPP;
+		}
+		break;
+	}
+
+	kfree_skb(skb);
+
+	return r;
+}
+
+static int hci_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (!hdev->ops->tm_send) {
+		kfree_skb(skb);
+		return -ENOTSUPP;
+	}
+
+	return hdev->ops->tm_send(hdev, skb);
+}
+
+static int hci_check_presence(struct nfc_dev *nfc_dev,
+			      struct nfc_target *target)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (!hdev->ops->check_presence)
+		return 0;
+
+	return hdev->ops->check_presence(hdev, target);
+}
+
+static int hci_discover_se(struct nfc_dev *nfc_dev)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (hdev->ops->discover_se)
+		return hdev->ops->discover_se(hdev);
+
+	return 0;
+}
+
+static int hci_enable_se(struct nfc_dev *nfc_dev, u32 se_idx)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (hdev->ops->enable_se)
+		return hdev->ops->enable_se(hdev, se_idx);
+
+	return 0;
+}
+
+static int hci_disable_se(struct nfc_dev *nfc_dev, u32 se_idx)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (hdev->ops->disable_se)
+		return hdev->ops->disable_se(hdev, se_idx);
+
+	return 0;
+}
+
+static int hci_se_io(struct nfc_dev *nfc_dev, u32 se_idx,
+		     u8 *apdu, size_t apdu_length,
+		     se_io_cb_t cb, void *cb_context)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (hdev->ops->se_io)
+		return hdev->ops->se_io(hdev, se_idx, apdu,
+					apdu_length, cb, cb_context);
+
+	return 0;
+}
+
+static void nfc_hci_failure(struct nfc_hci_dev *hdev, int err)
+{
+	mutex_lock(&hdev->msg_tx_mutex);
+
+	if (hdev->cmd_pending_msg == NULL) {
+		nfc_driver_failure(hdev->ndev, err);
+		goto exit;
+	}
+
+	__nfc_hci_cmd_completion(hdev, err, NULL);
+
+exit:
+	mutex_unlock(&hdev->msg_tx_mutex);
+}
+
+static void nfc_hci_llc_failure(struct nfc_hci_dev *hdev, int err)
+{
+	nfc_hci_failure(hdev, err);
+}
+
+static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)
+{
+	struct hcp_packet *packet;
+	u8 type;
+	u8 instruction;
+	struct sk_buff *hcp_skb;
+	u8 pipe;
+	struct sk_buff *frag_skb;
+	int msg_len;
+
+	if (!pskb_may_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN)) {
+		kfree_skb(skb);
+		return;
+	}
+
+	packet = (struct hcp_packet *)skb->data;
+	if ((packet->header & ~NFC_HCI_FRAGMENT) == 0) {
+		skb_queue_tail(&hdev->rx_hcp_frags, skb);
+		return;
+	}
+
+	/* it's the last fragment. Does it need re-aggregation? */
+	if (skb_queue_len(&hdev->rx_hcp_frags)) {
+		pipe = packet->header & NFC_HCI_FRAGMENT;
+		skb_queue_tail(&hdev->rx_hcp_frags, skb);
+
+		msg_len = 0;
+		skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
+			msg_len += (frag_skb->len -
+				    NFC_HCI_HCP_PACKET_HEADER_LEN);
+		}
+
+		hcp_skb = nfc_alloc_recv_skb(NFC_HCI_HCP_PACKET_HEADER_LEN +
+					     msg_len, GFP_KERNEL);
+		if (hcp_skb == NULL) {
+			nfc_hci_failure(hdev, -ENOMEM);
+			return;
+		}
+
+		skb_put_u8(hcp_skb, pipe);
+
+		skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
+			msg_len = frag_skb->len - NFC_HCI_HCP_PACKET_HEADER_LEN;
+			skb_put_data(hcp_skb,
+				     frag_skb->data + NFC_HCI_HCP_PACKET_HEADER_LEN,
+				     msg_len);
+		}
+
+		skb_queue_purge(&hdev->rx_hcp_frags);
+	} else {
+		packet->header &= NFC_HCI_FRAGMENT;
+		hcp_skb = skb;
+	}
+
+	/* if this is a response, dispatch immediately to
+	 * unblock waiting cmd context. Otherwise, enqueue to dispatch
+	 * in separate context where handler can also execute command.
+	 */
+	if (!pskb_may_pull(hcp_skb, NFC_HCI_HCP_HEADER_LEN)) {
+		kfree_skb(hcp_skb);
+		return;
+	}
+
+	packet = (struct hcp_packet *)hcp_skb->data;
+	type = HCP_MSG_GET_TYPE(packet->message.header);
+	if (type == NFC_HCI_HCP_RESPONSE) {
+		pipe = packet->header;
+		instruction = HCP_MSG_GET_CMD(packet->message.header);
+		skb_pull(hcp_skb, NFC_HCI_HCP_PACKET_HEADER_LEN +
+			 NFC_HCI_HCP_MESSAGE_HEADER_LEN);
+		nfc_hci_hcp_message_rx(hdev, pipe, type, instruction, hcp_skb);
+	} else {
+		skb_queue_tail(&hdev->msg_rx_queue, hcp_skb);
+		schedule_work(&hdev->msg_rx_work);
+	}
+}
+
+static int hci_fw_download(struct nfc_dev *nfc_dev, const char *firmware_name)
+{
+	struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
+
+	if (!hdev->ops->fw_download)
+		return -ENOTSUPP;
+
+	return hdev->ops->fw_download(hdev, firmware_name);
+}
+
+static const struct nfc_ops hci_nfc_ops = {
+	.dev_up = hci_dev_up,
+	.dev_down = hci_dev_down,
+	.start_poll = hci_start_poll,
+	.stop_poll = hci_stop_poll,
+	.dep_link_up = hci_dep_link_up,
+	.dep_link_down = hci_dep_link_down,
+	.activate_target = hci_activate_target,
+	.deactivate_target = hci_deactivate_target,
+	.im_transceive = hci_transceive,
+	.tm_send = hci_tm_send,
+	.check_presence = hci_check_presence,
+	.fw_download = hci_fw_download,
+	.discover_se = hci_discover_se,
+	.enable_se = hci_enable_se,
+	.disable_se = hci_disable_se,
+	.se_io = hci_se_io,
+};
+
+struct nfc_hci_dev *nfc_hci_allocate_device(const struct nfc_hci_ops *ops,
+					    struct nfc_hci_init_data *init_data,
+					    unsigned long quirks,
+					    u32 protocols,
+					    const char *llc_name,
+					    int tx_headroom,
+					    int tx_tailroom,
+					    int max_link_payload)
+{
+	struct nfc_hci_dev *hdev;
+
+	if (ops->xmit == NULL)
+		return NULL;
+
+	if (protocols == 0)
+		return NULL;
+
+	hdev = kzalloc_obj(struct nfc_hci_dev);
+	if (hdev == NULL)
+		return NULL;
+
+	hdev->llc = nfc_llc_allocate(llc_name, hdev, ops->xmit,
+				     nfc_hci_recv_from_llc, tx_headroom,
+				     tx_tailroom, nfc_hci_llc_failure);
+	if (hdev->llc == NULL) {
+		kfree(hdev);
+		return NULL;
+	}
+
+	hdev->ndev = nfc_allocate_device(&hci_nfc_ops, protocols,
+					 tx_headroom + HCI_CMDS_HEADROOM,
+					 tx_tailroom);
+	if (!hdev->ndev) {
+		nfc_llc_free(hdev->llc);
+		kfree(hdev);
+		return NULL;
+	}
+
+	hdev->ops = ops;
+	hdev->max_data_link_payload = max_link_payload;
+	hdev->init_data = *init_data;
+
+	nfc_set_drvdata(hdev->ndev, hdev);
+
+	nfc_hci_reset_pipes(hdev);
+
+	hdev->quirks = quirks;
+
+	return hdev;
+}
+EXPORT_SYMBOL(nfc_hci_allocate_device);
+
+void nfc_hci_free_device(struct nfc_hci_dev *hdev)
+{
+	nfc_free_device(hdev->ndev);
+	nfc_llc_free(hdev->llc);
+	kfree(hdev);
+}
+EXPORT_SYMBOL(nfc_hci_free_device);
+
+int nfc_hci_register_device(struct nfc_hci_dev *hdev)
+{
+	mutex_init(&hdev->msg_tx_mutex);
+
+	INIT_LIST_HEAD(&hdev->msg_tx_queue);
+
+	INIT_WORK(&hdev->msg_tx_work, nfc_hci_msg_tx_work);
+
+	timer_setup(&hdev->cmd_timer, nfc_hci_cmd_timeout, 0);
+
+	skb_queue_head_init(&hdev->rx_hcp_frags);
+
+	INIT_WORK(&hdev->msg_rx_work, nfc_hci_msg_rx_work);
+
+	skb_queue_head_init(&hdev->msg_rx_queue);
+
+	return nfc_register_device(hdev->ndev);
+}
+EXPORT_SYMBOL(nfc_hci_register_device);
+
+void nfc_hci_unregister_device(struct nfc_hci_dev *hdev)
+{
+	struct hci_msg *msg, *n;
+
+	mutex_lock(&hdev->msg_tx_mutex);
+
+	if (hdev->cmd_pending_msg) {
+		if (hdev->cmd_pending_msg->cb)
+			hdev->cmd_pending_msg->cb(
+					     hdev->cmd_pending_msg->cb_context,
+					     NULL, -ESHUTDOWN);
+		kfree(hdev->cmd_pending_msg);
+		hdev->cmd_pending_msg = NULL;
+	}
+
+	hdev->shutting_down = true;
+
+	mutex_unlock(&hdev->msg_tx_mutex);
+
+	timer_delete_sync(&hdev->cmd_timer);
+	cancel_work_sync(&hdev->msg_tx_work);
+
+	cancel_work_sync(&hdev->msg_rx_work);
+
+	nfc_unregister_device(hdev->ndev);
+
+	skb_queue_purge(&hdev->rx_hcp_frags);
+	skb_queue_purge(&hdev->msg_rx_queue);
+
+	list_for_each_entry_safe(msg, n, &hdev->msg_tx_queue, msg_l) {
+		list_del(&msg->msg_l);
+		skb_queue_purge(&msg->msg_frags);
+		kfree(msg);
+	}
+}
+EXPORT_SYMBOL(nfc_hci_unregister_device);
+
+void nfc_hci_set_clientdata(struct nfc_hci_dev *hdev, void *clientdata)
+{
+	hdev->clientdata = clientdata;
+}
+EXPORT_SYMBOL(nfc_hci_set_clientdata);
+
+void *nfc_hci_get_clientdata(struct nfc_hci_dev *hdev)
+{
+	return hdev->clientdata;
+}
+EXPORT_SYMBOL(nfc_hci_get_clientdata);
+
+void nfc_hci_driver_failure(struct nfc_hci_dev *hdev, int err)
+{
+	nfc_hci_failure(hdev, err);
+}
+EXPORT_SYMBOL(nfc_hci_driver_failure);
+
+void nfc_hci_recv_frame(struct nfc_hci_dev *hdev, struct sk_buff *skb)
+{
+	nfc_llc_rcv_from_drv(hdev->llc, skb);
+}
+EXPORT_SYMBOL(nfc_hci_recv_frame);
+
+static int __init nfc_hci_init(void)
+{
+	return nfc_llc_init();
+}
+
+static void __exit nfc_hci_exit(void)
+{
+	nfc_llc_exit();
+}
+
+subsys_initcall(nfc_hci_init);
+module_exit(nfc_hci_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_DESCRIPTION("NFC HCI Core");
diff --git a/net/nfc/hci/hci.h b/net/nfc/hci/hci.h
new file mode 100644
index 000000000..a59c96fcf
--- /dev/null
+++ b/net/nfc/hci/hci.h
@@ -0,0 +1,120 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+/*
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#ifndef __LOCAL_HCI_H
+#define __LOCAL_HCI_H
+
+#include <net/nfc/hci.h>
+
+struct gate_pipe_map {
+	u8 gate;
+	u8 pipe;
+};
+
+struct hcp_message {
+	u8 header;		/* type -cmd,evt,rsp- + instruction */
+	u8 data[];
+} __packed;
+
+struct hcp_packet {
+	u8 header;		/* cbit+pipe */
+	struct hcp_message message;
+} __packed;
+
+struct hcp_exec_waiter {
+	wait_queue_head_t *wq;
+	bool exec_complete;
+	int exec_result;
+	struct sk_buff *result_skb;
+};
+
+struct hci_msg {
+	struct list_head msg_l;
+	struct sk_buff_head msg_frags;
+	bool wait_response;
+	data_exchange_cb_t cb;
+	void *cb_context;
+	unsigned long completion_delay;
+};
+
+struct hci_create_pipe_params {
+	u8 src_gate;
+	u8 dest_host;
+	u8 dest_gate;
+} __packed;
+
+struct hci_create_pipe_resp {
+	u8 src_host;
+	u8 src_gate;
+	u8 dest_host;
+	u8 dest_gate;
+	u8 pipe;
+} __packed;
+
+struct hci_delete_pipe_noti {
+	u8 pipe;
+} __packed;
+
+struct hci_all_pipe_cleared_noti {
+	u8 host;
+} __packed;
+
+#define NFC_HCI_FRAGMENT	0x7f
+
+#define HCP_HEADER(type, instr) ((((type) & 0x03) << 6) | ((instr) & 0x3f))
+#define HCP_MSG_GET_TYPE(header) ((header & 0xc0) >> 6)
+#define HCP_MSG_GET_CMD(header) (header & 0x3f)
+
+int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
+			   u8 type, u8 instruction,
+			   const u8 *payload, size_t payload_len,
+			   data_exchange_cb_t cb, void *cb_context,
+			   unsigned long completion_delay);
+
+void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
+			    u8 instruction, struct sk_buff *skb);
+
+/* HCP headers */
+#define NFC_HCI_HCP_PACKET_HEADER_LEN	1
+#define NFC_HCI_HCP_MESSAGE_HEADER_LEN	1
+#define NFC_HCI_HCP_HEADER_LEN		2
+
+/* HCP types */
+#define NFC_HCI_HCP_COMMAND	0x00
+#define NFC_HCI_HCP_EVENT	0x01
+#define NFC_HCI_HCP_RESPONSE	0x02
+
+/* Generic commands */
+#define NFC_HCI_ANY_SET_PARAMETER	0x01
+#define NFC_HCI_ANY_GET_PARAMETER	0x02
+#define NFC_HCI_ANY_OPEN_PIPE		0x03
+#define NFC_HCI_ANY_CLOSE_PIPE		0x04
+
+/* Reader RF commands */
+#define NFC_HCI_WR_XCHG_DATA		0x10
+
+/* Admin commands */
+#define NFC_HCI_ADM_CREATE_PIPE			0x10
+#define NFC_HCI_ADM_DELETE_PIPE			0x11
+#define NFC_HCI_ADM_NOTIFY_PIPE_CREATED		0x12
+#define NFC_HCI_ADM_NOTIFY_PIPE_DELETED		0x13
+#define NFC_HCI_ADM_CLEAR_ALL_PIPE		0x14
+#define NFC_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED	0x15
+
+/* Generic responses */
+#define NFC_HCI_ANY_OK				0x00
+#define NFC_HCI_ANY_E_NOT_CONNECTED		0x01
+#define NFC_HCI_ANY_E_CMD_PAR_UNKNOWN		0x02
+#define NFC_HCI_ANY_E_NOK			0x03
+#define NFC_HCI_ANY_E_PIPES_FULL		0x04
+#define NFC_HCI_ANY_E_REG_PAR_UNKNOWN		0x05
+#define NFC_HCI_ANY_E_PIPE_NOT_OPENED		0x06
+#define NFC_HCI_ANY_E_CMD_NOT_SUPPORTED		0x07
+#define NFC_HCI_ANY_E_INHIBITED			0x08
+#define NFC_HCI_ANY_E_TIMEOUT			0x09
+#define NFC_HCI_ANY_E_REG_ACCESS_DENIED		0x0a
+#define NFC_HCI_ANY_E_PIPE_ACCESS_DENIED	0x0b
+
+#endif /* __LOCAL_HCI_H */
diff --git a/net/nfc/hci/hcp.c b/net/nfc/hci/hcp.c
new file mode 100644
index 000000000..4d19c697d
--- /dev/null
+++ b/net/nfc/hci/hcp.c
@@ -0,0 +1,136 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "hci: %s: " fmt, __func__
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+
+#include <net/nfc/hci.h>
+
+#include "hci.h"
+
+/*
+ * Payload is the HCP message data only. Instruction will be prepended.
+ * Guarantees that cb will be called upon completion or timeout delay
+ * counted from the moment the cmd is sent to the transport.
+ */
+int nfc_hci_hcp_message_tx(struct nfc_hci_dev *hdev, u8 pipe,
+			   u8 type, u8 instruction,
+			   const u8 *payload, size_t payload_len,
+			   data_exchange_cb_t cb, void *cb_context,
+			   unsigned long completion_delay)
+{
+	struct nfc_dev *ndev = hdev->ndev;
+	struct hci_msg *cmd;
+	const u8 *ptr = payload;
+	int hci_len, err;
+	bool firstfrag = true;
+
+	cmd = kzalloc_obj(struct hci_msg);
+	if (cmd == NULL)
+		return -ENOMEM;
+
+	INIT_LIST_HEAD(&cmd->msg_l);
+	skb_queue_head_init(&cmd->msg_frags);
+	cmd->wait_response = (type == NFC_HCI_HCP_COMMAND) ? true : false;
+	cmd->cb = cb;
+	cmd->cb_context = cb_context;
+	cmd->completion_delay = completion_delay;
+
+	hci_len = payload_len + 1;
+	while (hci_len > 0) {
+		struct sk_buff *skb;
+		int skb_len, data_link_len;
+		struct hcp_packet *packet;
+
+		if (NFC_HCI_HCP_PACKET_HEADER_LEN + hci_len <=
+		    hdev->max_data_link_payload)
+			data_link_len = hci_len;
+		else
+			data_link_len = hdev->max_data_link_payload -
+					NFC_HCI_HCP_PACKET_HEADER_LEN;
+
+		skb_len = ndev->tx_headroom + NFC_HCI_HCP_PACKET_HEADER_LEN +
+			  data_link_len + ndev->tx_tailroom;
+		hci_len -= data_link_len;
+
+		skb = alloc_skb(skb_len, GFP_KERNEL);
+		if (skb == NULL) {
+			err = -ENOMEM;
+			goto out_skb_err;
+		}
+		skb_reserve(skb, ndev->tx_headroom);
+
+		skb_put(skb, NFC_HCI_HCP_PACKET_HEADER_LEN + data_link_len);
+
+		/* Only the last fragment will have the cb bit set to 1 */
+		packet = (struct hcp_packet *)skb->data;
+		packet->header = pipe;
+		if (firstfrag) {
+			firstfrag = false;
+			packet->message.header = HCP_HEADER(type, instruction);
+		} else {
+			packet->message.header = *ptr++;
+		}
+		if (ptr) {
+			memcpy(packet->message.data, ptr, data_link_len - 1);
+			ptr += data_link_len - 1;
+		}
+
+		/* This is the last fragment, set the cb bit */
+		if (hci_len == 0)
+			packet->header |= ~NFC_HCI_FRAGMENT;
+
+		skb_queue_tail(&cmd->msg_frags, skb);
+	}
+
+	mutex_lock(&hdev->msg_tx_mutex);
+
+	if (hdev->shutting_down) {
+		err = -ESHUTDOWN;
+		mutex_unlock(&hdev->msg_tx_mutex);
+		goto out_skb_err;
+	}
+
+	list_add_tail(&cmd->msg_l, &hdev->msg_tx_queue);
+	mutex_unlock(&hdev->msg_tx_mutex);
+
+	schedule_work(&hdev->msg_tx_work);
+
+	return 0;
+
+out_skb_err:
+	skb_queue_purge(&cmd->msg_frags);
+	kfree(cmd);
+
+	return err;
+}
+
+/*
+ * Receive hcp message for pipe, with type and cmd.
+ * skb contains optional message data only.
+ */
+void nfc_hci_hcp_message_rx(struct nfc_hci_dev *hdev, u8 pipe, u8 type,
+			    u8 instruction, struct sk_buff *skb)
+{
+	switch (type) {
+	case NFC_HCI_HCP_RESPONSE:
+		nfc_hci_resp_received(hdev, instruction, skb);
+		break;
+	case NFC_HCI_HCP_COMMAND:
+		nfc_hci_cmd_received(hdev, pipe, instruction, skb);
+		break;
+	case NFC_HCI_HCP_EVENT:
+		nfc_hci_event_received(hdev, pipe, instruction, skb);
+		break;
+	default:
+		pr_err("UNKNOWN MSG Type %d, instruction=%d\n",
+		       type, instruction);
+		kfree_skb(skb);
+		break;
+	}
+}
diff --git a/net/nfc/hci/llc.c b/net/nfc/hci/llc.c
new file mode 100644
index 000000000..51dfa0d5d
--- /dev/null
+++ b/net/nfc/hci/llc.c
@@ -0,0 +1,141 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Link Layer Control manager
+ *
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#include <net/nfc/llc.h>
+
+#include "llc.h"
+
+static LIST_HEAD(llc_engines);
+
+int __init nfc_llc_init(void)
+{
+	int r;
+
+	r = nfc_llc_nop_register();
+	if (r)
+		goto exit;
+
+	r = nfc_llc_shdlc_register();
+	if (r)
+		goto exit;
+
+	return 0;
+
+exit:
+	nfc_llc_exit();
+	return r;
+}
+
+static void nfc_llc_del_engine(struct nfc_llc_engine *llc_engine)
+{
+	list_del(&llc_engine->entry);
+	kfree_const(llc_engine->name);
+	kfree(llc_engine);
+}
+
+void nfc_llc_exit(void)
+{
+	struct nfc_llc_engine *llc_engine, *n;
+
+	list_for_each_entry_safe(llc_engine, n, &llc_engines, entry)
+		nfc_llc_del_engine(llc_engine);
+}
+
+int nfc_llc_register(const char *name, const struct nfc_llc_ops *ops)
+{
+	struct nfc_llc_engine *llc_engine;
+
+	llc_engine = kzalloc_obj(struct nfc_llc_engine);
+	if (llc_engine == NULL)
+		return -ENOMEM;
+
+	llc_engine->name = kstrdup_const(name, GFP_KERNEL);
+	if (llc_engine->name == NULL) {
+		kfree(llc_engine);
+		return -ENOMEM;
+	}
+	llc_engine->ops = ops;
+
+	INIT_LIST_HEAD(&llc_engine->entry);
+	list_add_tail(&llc_engine->entry, &llc_engines);
+
+	return 0;
+}
+
+static struct nfc_llc_engine *nfc_llc_name_to_engine(const char *name)
+{
+	struct nfc_llc_engine *llc_engine;
+
+	list_for_each_entry(llc_engine, &llc_engines, entry) {
+		if (strcmp(llc_engine->name, name) == 0)
+			return llc_engine;
+	}
+
+	return NULL;
+}
+
+struct nfc_llc *nfc_llc_allocate(const char *name, struct nfc_hci_dev *hdev,
+				 xmit_to_drv_t xmit_to_drv,
+				 rcv_to_hci_t rcv_to_hci, int tx_headroom,
+				 int tx_tailroom, llc_failure_t llc_failure)
+{
+	struct nfc_llc_engine *llc_engine;
+	struct nfc_llc *llc;
+
+	llc_engine = nfc_llc_name_to_engine(name);
+	if (llc_engine == NULL)
+		return NULL;
+
+	llc = kzalloc_obj(struct nfc_llc);
+	if (llc == NULL)
+		return NULL;
+
+	llc->data = llc_engine->ops->init(hdev, xmit_to_drv, rcv_to_hci,
+					  tx_headroom, tx_tailroom,
+					  &llc->rx_headroom, &llc->rx_tailroom,
+					  llc_failure);
+	if (llc->data == NULL) {
+		kfree(llc);
+		return NULL;
+	}
+	llc->ops = llc_engine->ops;
+
+	return llc;
+}
+
+void nfc_llc_free(struct nfc_llc *llc)
+{
+	llc->ops->deinit(llc);
+	kfree(llc);
+}
+
+int nfc_llc_start(struct nfc_llc *llc)
+{
+	return llc->ops->start(llc);
+}
+EXPORT_SYMBOL(nfc_llc_start);
+
+int nfc_llc_stop(struct nfc_llc *llc)
+{
+	return llc->ops->stop(llc);
+}
+EXPORT_SYMBOL(nfc_llc_stop);
+
+void nfc_llc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb)
+{
+	llc->ops->rcv_from_drv(llc, skb);
+}
+
+int nfc_llc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb)
+{
+	return llc->ops->xmit_from_hci(llc, skb);
+}
+
+void *nfc_llc_get_data(struct nfc_llc *llc)
+{
+	return llc->data;
+}
diff --git a/net/nfc/hci/llc.h b/net/nfc/hci/llc.h
new file mode 100644
index 000000000..09914608e
--- /dev/null
+++ b/net/nfc/hci/llc.h
@@ -0,0 +1,55 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Link Layer Control manager
+ *
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#ifndef __LOCAL_LLC_H_
+#define __LOCAL_LLC_H_
+
+#include <net/nfc/hci.h>
+#include <net/nfc/llc.h>
+#include <linux/skbuff.h>
+
+struct nfc_llc_ops {
+	void *(*init) (struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv,
+		       rcv_to_hci_t rcv_to_hci, int tx_headroom,
+		       int tx_tailroom, int *rx_headroom, int *rx_tailroom,
+		       llc_failure_t llc_failure);
+	void (*deinit) (struct nfc_llc *llc);
+	int (*start) (struct nfc_llc *llc);
+	int (*stop) (struct nfc_llc *llc);
+	void (*rcv_from_drv) (struct nfc_llc *llc, struct sk_buff *skb);
+	int (*xmit_from_hci) (struct nfc_llc *llc, struct sk_buff *skb);
+};
+
+struct nfc_llc_engine {
+	const char *name;
+	const struct nfc_llc_ops *ops;
+	struct list_head entry;
+};
+
+struct nfc_llc {
+	void *data;
+	const struct nfc_llc_ops *ops;
+	int rx_headroom;
+	int rx_tailroom;
+};
+
+void *nfc_llc_get_data(struct nfc_llc *llc);
+
+int nfc_llc_register(const char *name, const struct nfc_llc_ops *ops);
+
+int nfc_llc_nop_register(void);
+
+#if defined(CONFIG_NFC_SHDLC)
+int nfc_llc_shdlc_register(void);
+#else
+static inline int nfc_llc_shdlc_register(void)
+{
+	return 0;
+}
+#endif
+
+#endif /* __LOCAL_LLC_H_ */
diff --git a/net/nfc/hci/llc_nop.c b/net/nfc/hci/llc_nop.c
new file mode 100644
index 000000000..f9c826a13
--- /dev/null
+++ b/net/nfc/hci/llc_nop.c
@@ -0,0 +1,86 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * nop (passthrough) Link Layer Control
+ *
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#include <linux/types.h>
+
+#include "llc.h"
+
+struct llc_nop {
+	struct nfc_hci_dev *hdev;
+	xmit_to_drv_t xmit_to_drv;
+	rcv_to_hci_t rcv_to_hci;
+	int tx_headroom;
+	int tx_tailroom;
+	llc_failure_t llc_failure;
+};
+
+static void *llc_nop_init(struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv,
+			  rcv_to_hci_t rcv_to_hci, int tx_headroom,
+			  int tx_tailroom, int *rx_headroom, int *rx_tailroom,
+			  llc_failure_t llc_failure)
+{
+	struct llc_nop *llc_nop;
+
+	*rx_headroom = 0;
+	*rx_tailroom = 0;
+
+	llc_nop = kzalloc_obj(struct llc_nop);
+	if (llc_nop == NULL)
+		return NULL;
+
+	llc_nop->hdev = hdev;
+	llc_nop->xmit_to_drv = xmit_to_drv;
+	llc_nop->rcv_to_hci = rcv_to_hci;
+	llc_nop->tx_headroom = tx_headroom;
+	llc_nop->tx_tailroom = tx_tailroom;
+	llc_nop->llc_failure = llc_failure;
+
+	return llc_nop;
+}
+
+static void llc_nop_deinit(struct nfc_llc *llc)
+{
+	kfree(nfc_llc_get_data(llc));
+}
+
+static int llc_nop_start(struct nfc_llc *llc)
+{
+	return 0;
+}
+
+static int llc_nop_stop(struct nfc_llc *llc)
+{
+	return 0;
+}
+
+static void llc_nop_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb)
+{
+	struct llc_nop *llc_nop = nfc_llc_get_data(llc);
+
+	llc_nop->rcv_to_hci(llc_nop->hdev, skb);
+}
+
+static int llc_nop_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb)
+{
+	struct llc_nop *llc_nop = nfc_llc_get_data(llc);
+
+	return llc_nop->xmit_to_drv(llc_nop->hdev, skb);
+}
+
+static const struct nfc_llc_ops llc_nop_ops = {
+	.init = llc_nop_init,
+	.deinit = llc_nop_deinit,
+	.start = llc_nop_start,
+	.stop = llc_nop_stop,
+	.rcv_from_drv = llc_nop_rcv_from_drv,
+	.xmit_from_hci = llc_nop_xmit_from_hci,
+};
+
+int nfc_llc_nop_register(void)
+{
+	return nfc_llc_register(LLC_NOP_NAME, &llc_nop_ops);
+}
diff --git a/net/nfc/hci/llc_shdlc.c b/net/nfc/hci/llc_shdlc.c
new file mode 100644
index 000000000..6819695d9
--- /dev/null
+++ b/net/nfc/hci/llc_shdlc.c
@@ -0,0 +1,826 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * shdlc Link Layer Control
+ *
+ * Copyright (C) 2012  Intel Corporation. All rights reserved.
+ */
+
+#define pr_fmt(fmt) "shdlc: %s: " fmt, __func__
+
+#include <linux/types.h>
+#include <linux/sched.h>
+#include <linux/wait.h>
+#include <linux/slab.h>
+#include <linux/skbuff.h>
+
+#include "llc.h"
+
+enum shdlc_state {
+	SHDLC_DISCONNECTED = 0,
+	SHDLC_CONNECTING = 1,
+	SHDLC_NEGOTIATING = 2,
+	SHDLC_HALF_CONNECTED = 3,
+	SHDLC_CONNECTED = 4
+};
+
+struct llc_shdlc {
+	struct nfc_hci_dev *hdev;
+	xmit_to_drv_t xmit_to_drv;
+	rcv_to_hci_t rcv_to_hci;
+
+	struct mutex state_mutex;
+	enum shdlc_state state;
+	int hard_fault;
+
+	wait_queue_head_t *connect_wq;
+	int connect_tries;
+	int connect_result;
+	struct timer_list connect_timer;/* aka T3 in spec 10.6.1 */
+
+	u8 w;				/* window size */
+	bool srej_support;
+
+	struct timer_list t1_timer;	/* send ack timeout */
+	bool t1_active;
+
+	struct timer_list t2_timer;	/* guard/retransmit timeout */
+	bool t2_active;
+
+	int ns;				/* next seq num for send */
+	int nr;				/* next expected seq num for receive */
+	int dnr;			/* oldest sent unacked seq num */
+
+	struct sk_buff_head rcv_q;
+
+	struct sk_buff_head send_q;
+	bool rnr;			/* other side is not ready to receive */
+
+	struct sk_buff_head ack_pending_q;
+
+	struct work_struct sm_work;
+
+	int tx_headroom;
+	int tx_tailroom;
+
+	llc_failure_t llc_failure;
+};
+
+#define SHDLC_LLC_HEAD_ROOM	2
+
+#define SHDLC_MAX_WINDOW	4
+#define SHDLC_SREJ_SUPPORT	false
+
+#define SHDLC_CONTROL_HEAD_MASK	0xe0
+#define SHDLC_CONTROL_HEAD_I	0x80
+#define SHDLC_CONTROL_HEAD_I2	0xa0
+#define SHDLC_CONTROL_HEAD_S	0xc0
+#define SHDLC_CONTROL_HEAD_U	0xe0
+
+#define SHDLC_CONTROL_NS_MASK	0x38
+#define SHDLC_CONTROL_NR_MASK	0x07
+#define SHDLC_CONTROL_TYPE_MASK	0x18
+
+#define SHDLC_CONTROL_M_MASK	0x1f
+
+enum sframe_type {
+	S_FRAME_RR = 0x00,
+	S_FRAME_REJ = 0x01,
+	S_FRAME_RNR = 0x02,
+	S_FRAME_SREJ = 0x03
+};
+
+enum uframe_modifier {
+	U_FRAME_UA = 0x06,
+	U_FRAME_RSET = 0x19
+};
+
+#define SHDLC_CONNECT_VALUE_MS	5
+#define SHDLC_T1_VALUE_MS(w)	((5 * w) / 4)
+#define SHDLC_T2_VALUE_MS	300
+
+#define SHDLC_DUMP_SKB(info, skb)				  \
+do {								  \
+	pr_debug("%s:\n", info);				  \
+	print_hex_dump(KERN_DEBUG, "shdlc: ", DUMP_PREFIX_OFFSET, \
+		       16, 1, skb->data, skb->len, 0);		  \
+} while (0)
+
+/* checks x < y <= z modulo 8 */
+static bool llc_shdlc_x_lt_y_lteq_z(int x, int y, int z)
+{
+	if (x < z)
+		return ((x < y) && (y <= z)) ? true : false;
+	else
+		return ((y > x) || (y <= z)) ? true : false;
+}
+
+/* checks x <= y < z modulo 8 */
+static bool llc_shdlc_x_lteq_y_lt_z(int x, int y, int z)
+{
+	if (x <= z)
+		return ((x <= y) && (y < z)) ? true : false;
+	else			/* x > z -> z+8 > x */
+		return ((y >= x) || (y < z)) ? true : false;
+}
+
+static struct sk_buff *llc_shdlc_alloc_skb(const struct llc_shdlc *shdlc,
+					   int payload_len)
+{
+	struct sk_buff *skb;
+
+	skb = alloc_skb(shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM +
+			shdlc->tx_tailroom + payload_len, GFP_KERNEL);
+	if (skb)
+		skb_reserve(skb, shdlc->tx_headroom + SHDLC_LLC_HEAD_ROOM);
+
+	return skb;
+}
+
+/* immediately sends an S frame. */
+static int llc_shdlc_send_s_frame(const struct llc_shdlc *shdlc,
+				  enum sframe_type sframe_type, int nr)
+{
+	int r;
+	struct sk_buff *skb;
+
+	pr_debug("sframe_type=%d nr=%d\n", sframe_type, nr);
+
+	skb = llc_shdlc_alloc_skb(shdlc, 0);
+	if (skb == NULL)
+		return -ENOMEM;
+
+	*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_S | (sframe_type << 3) | nr;
+
+	r = shdlc->xmit_to_drv(shdlc->hdev, skb);
+
+	kfree_skb(skb);
+
+	return r;
+}
+
+/* immediately sends an U frame. skb may contain optional payload */
+static int llc_shdlc_send_u_frame(const struct llc_shdlc *shdlc,
+				  struct sk_buff *skb,
+				  enum uframe_modifier uframe_modifier)
+{
+	int r;
+
+	pr_debug("uframe_modifier=%d\n", uframe_modifier);
+
+	*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_U | uframe_modifier;
+
+	r = shdlc->xmit_to_drv(shdlc->hdev, skb);
+
+	kfree_skb(skb);
+
+	return r;
+}
+
+/*
+ * Free ack_pending frames until y_nr - 1, and reset t2 according to
+ * the remaining oldest ack_pending frame sent time
+ */
+static void llc_shdlc_reset_t2(struct llc_shdlc *shdlc, int y_nr)
+{
+	struct sk_buff *skb;
+	int dnr = shdlc->dnr;	/* MUST initially be < y_nr */
+
+	pr_debug("release ack pending up to frame %d excluded\n", y_nr);
+
+	while (dnr != y_nr) {
+		pr_debug("release ack pending frame %d\n", dnr);
+
+		skb = skb_dequeue(&shdlc->ack_pending_q);
+		kfree_skb(skb);
+
+		dnr = (dnr + 1) % 8;
+	}
+
+	if (skb_queue_empty(&shdlc->ack_pending_q)) {
+		if (shdlc->t2_active) {
+			timer_delete_sync(&shdlc->t2_timer);
+			shdlc->t2_active = false;
+
+			pr_debug("All sent frames acked. Stopped T2(retransmit)\n");
+		}
+	} else {
+		skb = skb_peek(&shdlc->ack_pending_q);
+
+		mod_timer(&shdlc->t2_timer, *(unsigned long *)skb->cb +
+			  msecs_to_jiffies(SHDLC_T2_VALUE_MS));
+		shdlc->t2_active = true;
+
+		pr_debug("Start T2(retransmit) for remaining unacked sent frames\n");
+	}
+}
+
+/*
+ * Receive validated frames from lower layer. skb contains HCI payload only.
+ * Handle according to algorithm at spec:10.8.2
+ */
+static void llc_shdlc_rcv_i_frame(struct llc_shdlc *shdlc,
+				  struct sk_buff *skb, int ns, int nr)
+{
+	int x_ns = ns;
+	int y_nr = nr;
+
+	pr_debug("recvd I-frame %d, remote waiting frame %d\n", ns, nr);
+
+	if (shdlc->state != SHDLC_CONNECTED)
+		goto exit;
+
+	if (x_ns != shdlc->nr) {
+		llc_shdlc_send_s_frame(shdlc, S_FRAME_REJ, shdlc->nr);
+		goto exit;
+	}
+
+	if (!shdlc->t1_active) {
+		shdlc->t1_active = true;
+		mod_timer(&shdlc->t1_timer, jiffies +
+			  msecs_to_jiffies(SHDLC_T1_VALUE_MS(shdlc->w)));
+		pr_debug("(re)Start T1(send ack)\n");
+	}
+
+	if (skb->len) {
+		shdlc->rcv_to_hci(shdlc->hdev, skb);
+		skb = NULL;
+	}
+
+	shdlc->nr = (shdlc->nr + 1) % 8;
+
+	if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) {
+		llc_shdlc_reset_t2(shdlc, y_nr);
+
+		shdlc->dnr = y_nr;
+	}
+
+exit:
+	kfree_skb(skb);
+}
+
+static void llc_shdlc_rcv_ack(struct llc_shdlc *shdlc, int y_nr)
+{
+	pr_debug("remote acked up to frame %d excluded\n", y_nr);
+
+	if (llc_shdlc_x_lt_y_lteq_z(shdlc->dnr, y_nr, shdlc->ns)) {
+		llc_shdlc_reset_t2(shdlc, y_nr);
+		shdlc->dnr = y_nr;
+	}
+}
+
+static void llc_shdlc_requeue_ack_pending(struct llc_shdlc *shdlc)
+{
+	struct sk_buff *skb;
+
+	pr_debug("ns reset to %d\n", shdlc->dnr);
+
+	while ((skb = skb_dequeue_tail(&shdlc->ack_pending_q))) {
+		skb_pull(skb, 1);	/* remove control field */
+		skb_queue_head(&shdlc->send_q, skb);
+	}
+	shdlc->ns = shdlc->dnr;
+}
+
+static void llc_shdlc_rcv_rej(struct llc_shdlc *shdlc, int y_nr)
+{
+	struct sk_buff *skb;
+
+	pr_debug("remote asks retransmission from frame %d\n", y_nr);
+
+	if (llc_shdlc_x_lteq_y_lt_z(shdlc->dnr, y_nr, shdlc->ns)) {
+		if (shdlc->t2_active) {
+			timer_delete_sync(&shdlc->t2_timer);
+			shdlc->t2_active = false;
+			pr_debug("Stopped T2(retransmit)\n");
+		}
+
+		if (shdlc->dnr != y_nr) {
+			while ((shdlc->dnr = ((shdlc->dnr + 1) % 8)) != y_nr) {
+				skb = skb_dequeue(&shdlc->ack_pending_q);
+				kfree_skb(skb);
+			}
+		}
+
+		llc_shdlc_requeue_ack_pending(shdlc);
+	}
+}
+
+/* See spec RR:10.8.3 REJ:10.8.4 */
+static void llc_shdlc_rcv_s_frame(struct llc_shdlc *shdlc,
+				  enum sframe_type s_frame_type, int nr)
+{
+	struct sk_buff *skb;
+
+	if (shdlc->state != SHDLC_CONNECTED)
+		return;
+
+	switch (s_frame_type) {
+	case S_FRAME_RR:
+		llc_shdlc_rcv_ack(shdlc, nr);
+		if (shdlc->rnr == true) {	/* see SHDLC 10.7.7 */
+			shdlc->rnr = false;
+			if (shdlc->send_q.qlen == 0) {
+				skb = llc_shdlc_alloc_skb(shdlc, 0);
+				if (skb)
+					skb_queue_tail(&shdlc->send_q, skb);
+			}
+		}
+		break;
+	case S_FRAME_REJ:
+		llc_shdlc_rcv_rej(shdlc, nr);
+		break;
+	case S_FRAME_RNR:
+		llc_shdlc_rcv_ack(shdlc, nr);
+		shdlc->rnr = true;
+		break;
+	default:
+		break;
+	}
+}
+
+static void llc_shdlc_connect_complete(struct llc_shdlc *shdlc, int r)
+{
+	pr_debug("result=%d\n", r);
+
+	timer_delete_sync(&shdlc->connect_timer);
+
+	if (r == 0) {
+		shdlc->ns = 0;
+		shdlc->nr = 0;
+		shdlc->dnr = 0;
+
+		shdlc->state = SHDLC_HALF_CONNECTED;
+	} else {
+		shdlc->state = SHDLC_DISCONNECTED;
+	}
+
+	shdlc->connect_result = r;
+
+	wake_up(shdlc->connect_wq);
+}
+
+static int llc_shdlc_connect_initiate(const struct llc_shdlc *shdlc)
+{
+	struct sk_buff *skb;
+
+	skb = llc_shdlc_alloc_skb(shdlc, 2);
+	if (skb == NULL)
+		return -ENOMEM;
+
+	skb_put_u8(skb, SHDLC_MAX_WINDOW);
+	skb_put_u8(skb, SHDLC_SREJ_SUPPORT ? 1 : 0);
+
+	return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_RSET);
+}
+
+static int llc_shdlc_connect_send_ua(const struct llc_shdlc *shdlc)
+{
+	struct sk_buff *skb;
+
+	skb = llc_shdlc_alloc_skb(shdlc, 0);
+	if (skb == NULL)
+		return -ENOMEM;
+
+	return llc_shdlc_send_u_frame(shdlc, skb, U_FRAME_UA);
+}
+
+static void llc_shdlc_rcv_u_frame(struct llc_shdlc *shdlc,
+				  struct sk_buff *skb,
+				  enum uframe_modifier u_frame_modifier)
+{
+	u8 w = SHDLC_MAX_WINDOW;
+	bool srej_support = SHDLC_SREJ_SUPPORT;
+	int r;
+
+	pr_debug("u_frame_modifier=%d\n", u_frame_modifier);
+
+	switch (u_frame_modifier) {
+	case U_FRAME_RSET:
+		switch (shdlc->state) {
+		case SHDLC_NEGOTIATING:
+		case SHDLC_CONNECTING:
+			/*
+			 * We sent RSET, but chip wants to negotiate or we
+			 * got RSET before we managed to send out our.
+			 */
+			if (skb->len > 0)
+				w = skb->data[0];
+
+			if (skb->len > 1)
+				srej_support = skb->data[1] & 0x01 ? true :
+					       false;
+
+			if ((w <= SHDLC_MAX_WINDOW) &&
+			    (SHDLC_SREJ_SUPPORT || (srej_support == false))) {
+				shdlc->w = w;
+				shdlc->srej_support = srej_support;
+				r = llc_shdlc_connect_send_ua(shdlc);
+				llc_shdlc_connect_complete(shdlc, r);
+			}
+			break;
+		case SHDLC_HALF_CONNECTED:
+			/*
+			 * Chip resent RSET due to its timeout - Ignote it
+			 * as we already sent UA.
+			 */
+			break;
+		case SHDLC_CONNECTED:
+			/*
+			 * Chip wants to reset link. This is unexpected and
+			 * unsupported.
+			 */
+			shdlc->hard_fault = -ECONNRESET;
+			break;
+		default:
+			break;
+		}
+		break;
+	case U_FRAME_UA:
+		if ((shdlc->state == SHDLC_CONNECTING &&
+		     shdlc->connect_tries > 0) ||
+		    (shdlc->state == SHDLC_NEGOTIATING)) {
+			llc_shdlc_connect_complete(shdlc, 0);
+			shdlc->state = SHDLC_CONNECTED;
+		}
+		break;
+	default:
+		break;
+	}
+
+	kfree_skb(skb);
+}
+
+static void llc_shdlc_handle_rcv_queue(struct llc_shdlc *shdlc)
+{
+	struct sk_buff *skb;
+	u8 control;
+	int nr;
+	int ns;
+	enum sframe_type s_frame_type;
+	enum uframe_modifier u_frame_modifier;
+
+	if (shdlc->rcv_q.qlen)
+		pr_debug("rcvQlen=%d\n", shdlc->rcv_q.qlen);
+
+	while ((skb = skb_dequeue(&shdlc->rcv_q)) != NULL) {
+		control = skb->data[0];
+		skb_pull(skb, 1);
+		switch (control & SHDLC_CONTROL_HEAD_MASK) {
+		case SHDLC_CONTROL_HEAD_I:
+		case SHDLC_CONTROL_HEAD_I2:
+			if (shdlc->state == SHDLC_HALF_CONNECTED)
+				shdlc->state = SHDLC_CONNECTED;
+
+			ns = (control & SHDLC_CONTROL_NS_MASK) >> 3;
+			nr = control & SHDLC_CONTROL_NR_MASK;
+			llc_shdlc_rcv_i_frame(shdlc, skb, ns, nr);
+			break;
+		case SHDLC_CONTROL_HEAD_S:
+			if (shdlc->state == SHDLC_HALF_CONNECTED)
+				shdlc->state = SHDLC_CONNECTED;
+
+			s_frame_type = (control & SHDLC_CONTROL_TYPE_MASK) >> 3;
+			nr = control & SHDLC_CONTROL_NR_MASK;
+			llc_shdlc_rcv_s_frame(shdlc, s_frame_type, nr);
+			kfree_skb(skb);
+			break;
+		case SHDLC_CONTROL_HEAD_U:
+			u_frame_modifier = control & SHDLC_CONTROL_M_MASK;
+			llc_shdlc_rcv_u_frame(shdlc, skb, u_frame_modifier);
+			break;
+		default:
+			pr_err("UNKNOWN Control=%d\n", control);
+			kfree_skb(skb);
+			break;
+		}
+	}
+}
+
+static int llc_shdlc_w_used(int ns, int dnr)
+{
+	int unack_count;
+
+	if (dnr <= ns)
+		unack_count = ns - dnr;
+	else
+		unack_count = 8 - dnr + ns;
+
+	return unack_count;
+}
+
+/* Send frames according to algorithm at spec:10.8.1 */
+static void llc_shdlc_handle_send_queue(struct llc_shdlc *shdlc)
+{
+	struct sk_buff *skb;
+	int r;
+	unsigned long time_sent;
+
+	if (shdlc->send_q.qlen)
+		pr_debug("sendQlen=%d ns=%d dnr=%d rnr=%s w_room=%d unackQlen=%d\n",
+			 shdlc->send_q.qlen, shdlc->ns, shdlc->dnr,
+			 shdlc->rnr == false ? "false" : "true",
+			 shdlc->w - llc_shdlc_w_used(shdlc->ns, shdlc->dnr),
+			 shdlc->ack_pending_q.qlen);
+
+	while (shdlc->send_q.qlen && shdlc->ack_pending_q.qlen < shdlc->w &&
+	       (shdlc->rnr == false)) {
+
+		if (shdlc->t1_active) {
+			timer_delete_sync(&shdlc->t1_timer);
+			shdlc->t1_active = false;
+			pr_debug("Stopped T1(send ack)\n");
+		}
+
+		skb = skb_dequeue(&shdlc->send_q);
+
+		*(u8 *)skb_push(skb, 1) = SHDLC_CONTROL_HEAD_I | (shdlc->ns << 3) |
+					shdlc->nr;
+
+		pr_debug("Sending I-Frame %d, waiting to rcv %d\n", shdlc->ns,
+			 shdlc->nr);
+		SHDLC_DUMP_SKB("shdlc frame written", skb);
+
+		r = shdlc->xmit_to_drv(shdlc->hdev, skb);
+		if (r < 0) {
+			shdlc->hard_fault = r;
+			break;
+		}
+
+		shdlc->ns = (shdlc->ns + 1) % 8;
+
+		time_sent = jiffies;
+		*(unsigned long *)skb->cb = time_sent;
+
+		skb_queue_tail(&shdlc->ack_pending_q, skb);
+
+		if (shdlc->t2_active == false) {
+			shdlc->t2_active = true;
+			mod_timer(&shdlc->t2_timer, time_sent +
+				  msecs_to_jiffies(SHDLC_T2_VALUE_MS));
+			pr_debug("Started T2 (retransmit)\n");
+		}
+	}
+}
+
+static void llc_shdlc_connect_timeout(struct timer_list *t)
+{
+	struct llc_shdlc *shdlc = timer_container_of(shdlc, t, connect_timer);
+
+	schedule_work(&shdlc->sm_work);
+}
+
+static void llc_shdlc_t1_timeout(struct timer_list *t)
+{
+	struct llc_shdlc *shdlc = timer_container_of(shdlc, t, t1_timer);
+
+	pr_debug("SoftIRQ: need to send ack\n");
+
+	schedule_work(&shdlc->sm_work);
+}
+
+static void llc_shdlc_t2_timeout(struct timer_list *t)
+{
+	struct llc_shdlc *shdlc = timer_container_of(shdlc, t, t2_timer);
+
+	pr_debug("SoftIRQ: need to retransmit\n");
+
+	schedule_work(&shdlc->sm_work);
+}
+
+static void llc_shdlc_sm_work(struct work_struct *work)
+{
+	struct llc_shdlc *shdlc = container_of(work, struct llc_shdlc, sm_work);
+	int r;
+
+	mutex_lock(&shdlc->state_mutex);
+
+	switch (shdlc->state) {
+	case SHDLC_DISCONNECTED:
+		skb_queue_purge(&shdlc->rcv_q);
+		skb_queue_purge(&shdlc->send_q);
+		skb_queue_purge(&shdlc->ack_pending_q);
+		break;
+	case SHDLC_CONNECTING:
+		if (shdlc->hard_fault) {
+			llc_shdlc_connect_complete(shdlc, shdlc->hard_fault);
+			break;
+		}
+
+		if (shdlc->connect_tries++ < 5)
+			r = llc_shdlc_connect_initiate(shdlc);
+		else
+			r = -ETIME;
+		if (r < 0) {
+			llc_shdlc_connect_complete(shdlc, r);
+		} else {
+			mod_timer(&shdlc->connect_timer, jiffies +
+				  msecs_to_jiffies(SHDLC_CONNECT_VALUE_MS));
+
+			shdlc->state = SHDLC_NEGOTIATING;
+		}
+		break;
+	case SHDLC_NEGOTIATING:
+		if (timer_pending(&shdlc->connect_timer) == 0) {
+			shdlc->state = SHDLC_CONNECTING;
+			schedule_work(&shdlc->sm_work);
+		}
+
+		llc_shdlc_handle_rcv_queue(shdlc);
+
+		if (shdlc->hard_fault) {
+			llc_shdlc_connect_complete(shdlc, shdlc->hard_fault);
+			break;
+		}
+		break;
+	case SHDLC_HALF_CONNECTED:
+	case SHDLC_CONNECTED:
+		llc_shdlc_handle_rcv_queue(shdlc);
+		llc_shdlc_handle_send_queue(shdlc);
+
+		if (shdlc->t1_active && timer_pending(&shdlc->t1_timer) == 0) {
+			pr_debug("Handle T1(send ack) elapsed (T1 now inactive)\n");
+
+			shdlc->t1_active = false;
+			r = llc_shdlc_send_s_frame(shdlc, S_FRAME_RR,
+						   shdlc->nr);
+			if (r < 0)
+				shdlc->hard_fault = r;
+		}
+
+		if (shdlc->t2_active && timer_pending(&shdlc->t2_timer) == 0) {
+			pr_debug("Handle T2(retransmit) elapsed (T2 inactive)\n");
+
+			shdlc->t2_active = false;
+
+			llc_shdlc_requeue_ack_pending(shdlc);
+			llc_shdlc_handle_send_queue(shdlc);
+		}
+
+		if (shdlc->hard_fault)
+			shdlc->llc_failure(shdlc->hdev, shdlc->hard_fault);
+		break;
+	default:
+		break;
+	}
+	mutex_unlock(&shdlc->state_mutex);
+}
+
+/*
+ * Called from syscall context to establish shdlc link. Sleeps until
+ * link is ready or failure.
+ */
+static int llc_shdlc_connect(struct llc_shdlc *shdlc)
+{
+	DECLARE_WAIT_QUEUE_HEAD_ONSTACK(connect_wq);
+
+	mutex_lock(&shdlc->state_mutex);
+
+	shdlc->state = SHDLC_CONNECTING;
+	shdlc->connect_wq = &connect_wq;
+	shdlc->connect_tries = 0;
+	shdlc->connect_result = 1;
+
+	mutex_unlock(&shdlc->state_mutex);
+
+	schedule_work(&shdlc->sm_work);
+
+	wait_event(connect_wq, shdlc->connect_result != 1);
+
+	return shdlc->connect_result;
+}
+
+static void llc_shdlc_disconnect(struct llc_shdlc *shdlc)
+{
+	mutex_lock(&shdlc->state_mutex);
+
+	shdlc->state = SHDLC_DISCONNECTED;
+
+	mutex_unlock(&shdlc->state_mutex);
+
+	schedule_work(&shdlc->sm_work);
+}
+
+/*
+ * Receive an incoming shdlc frame. Frame has already been crc-validated.
+ * skb contains only LLC header and payload.
+ * If skb == NULL, it is a notification that the link below is dead.
+ */
+static void llc_shdlc_recv_frame(struct llc_shdlc *shdlc, struct sk_buff *skb)
+{
+	if (skb == NULL) {
+		pr_err("NULL Frame -> link is dead\n");
+		shdlc->hard_fault = -EREMOTEIO;
+	} else {
+		SHDLC_DUMP_SKB("incoming frame", skb);
+		skb_queue_tail(&shdlc->rcv_q, skb);
+	}
+
+	schedule_work(&shdlc->sm_work);
+}
+
+static void *llc_shdlc_init(struct nfc_hci_dev *hdev, xmit_to_drv_t xmit_to_drv,
+			    rcv_to_hci_t rcv_to_hci, int tx_headroom,
+			    int tx_tailroom, int *rx_headroom, int *rx_tailroom,
+			    llc_failure_t llc_failure)
+{
+	struct llc_shdlc *shdlc;
+
+	*rx_headroom = SHDLC_LLC_HEAD_ROOM;
+	*rx_tailroom = 0;
+
+	shdlc = kzalloc_obj(struct llc_shdlc);
+	if (shdlc == NULL)
+		return NULL;
+
+	mutex_init(&shdlc->state_mutex);
+	shdlc->state = SHDLC_DISCONNECTED;
+
+	timer_setup(&shdlc->connect_timer, llc_shdlc_connect_timeout, 0);
+	timer_setup(&shdlc->t1_timer, llc_shdlc_t1_timeout, 0);
+	timer_setup(&shdlc->t2_timer, llc_shdlc_t2_timeout, 0);
+
+	shdlc->w = SHDLC_MAX_WINDOW;
+	shdlc->srej_support = SHDLC_SREJ_SUPPORT;
+
+	skb_queue_head_init(&shdlc->rcv_q);
+	skb_queue_head_init(&shdlc->send_q);
+	skb_queue_head_init(&shdlc->ack_pending_q);
+
+	INIT_WORK(&shdlc->sm_work, llc_shdlc_sm_work);
+
+	shdlc->hdev = hdev;
+	shdlc->xmit_to_drv = xmit_to_drv;
+	shdlc->rcv_to_hci = rcv_to_hci;
+	shdlc->tx_headroom = tx_headroom;
+	shdlc->tx_tailroom = tx_tailroom;
+	shdlc->llc_failure = llc_failure;
+
+	return shdlc;
+}
+
+static void llc_shdlc_deinit(struct nfc_llc *llc)
+{
+	struct llc_shdlc *shdlc = nfc_llc_get_data(llc);
+
+	timer_shutdown_sync(&shdlc->connect_timer);
+	timer_shutdown_sync(&shdlc->t1_timer);
+	timer_shutdown_sync(&shdlc->t2_timer);
+	shdlc->t1_active = false;
+	shdlc->t2_active = false;
+
+	cancel_work_sync(&shdlc->sm_work);
+
+	skb_queue_purge(&shdlc->rcv_q);
+	skb_queue_purge(&shdlc->send_q);
+	skb_queue_purge(&shdlc->ack_pending_q);
+
+	kfree(shdlc);
+}
+
+static int llc_shdlc_start(struct nfc_llc *llc)
+{
+	struct llc_shdlc *shdlc = nfc_llc_get_data(llc);
+
+	return llc_shdlc_connect(shdlc);
+}
+
+static int llc_shdlc_stop(struct nfc_llc *llc)
+{
+	struct llc_shdlc *shdlc = nfc_llc_get_data(llc);
+
+	llc_shdlc_disconnect(shdlc);
+
+	return 0;
+}
+
+static void llc_shdlc_rcv_from_drv(struct nfc_llc *llc, struct sk_buff *skb)
+{
+	struct llc_shdlc *shdlc = nfc_llc_get_data(llc);
+
+	llc_shdlc_recv_frame(shdlc, skb);
+}
+
+static int llc_shdlc_xmit_from_hci(struct nfc_llc *llc, struct sk_buff *skb)
+{
+	struct llc_shdlc *shdlc = nfc_llc_get_data(llc);
+
+	skb_queue_tail(&shdlc->send_q, skb);
+
+	schedule_work(&shdlc->sm_work);
+
+	return 0;
+}
+
+static const struct nfc_llc_ops llc_shdlc_ops = {
+	.init = llc_shdlc_init,
+	.deinit = llc_shdlc_deinit,
+	.start = llc_shdlc_start,
+	.stop = llc_shdlc_stop,
+	.rcv_from_drv = llc_shdlc_rcv_from_drv,
+	.xmit_from_hci = llc_shdlc_xmit_from_hci,
+};
+
+int nfc_llc_shdlc_register(void)
+{
+	return nfc_llc_register(LLC_SHDLC_NAME, &llc_shdlc_ops);
+}