text: /*
   * Copyright (C) 2012  Intel Corporation. All rights reserved.
   *
   * This program is free software; you can redistribute it and/or modify
   * it under the terms of the GNU General Public License as published by
   * the Free Software Foundation; either version 2 of the License, or
   * (at your option) any later version.
   *
   * This program is distributed in the hope that it will be useful,
   * but WITHOUT ANY WARRANTY; without even the implied warranty of
   * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
   * GNU General Public License for more details.
   *
   * You should have received a copy of the GNU General Public License
   * along with this program; if not, see <http://www.gnu.org/licenses/>.
   */
  
  #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;
  	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)
  {
  	del_timer_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 gate = hdev->pipes[pipe].gate;
  	u8 status = NFC_HCI_ANY_OK;
  	struct hci_create_pipe_resp *create_info;
  	struct hci_delete_pipe_noti *delete_info;
  	struct hci_all_pipe_cleared_noti *cleared_info;
  
  	pr_debug("from gate %x pipe %x cmd %x\n", gate, pipe, cmd);
  
  	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;
  
  		/* 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;
  
  		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(sizeof(struct nfc_target), GFP_KERNEL);
  	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 = 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(unsigned long data)
  {
  	struct nfc_hci_dev *hdev = (struct nfc_hci_dev *)data;
  
  	schedule_work(&hdev->msg_tx_work);
  }
  
  static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,
  				 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 occured? 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;
  
  	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.
  	 */
  	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 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(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(sizeof(struct nfc_hci_dev), GFP_KERNEL);
  	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);
  
  	init_timer(&hdev->cmd_timer);
  	hdev->cmd_timer.data = (unsigned long)hdev;
  	hdev->cmd_timer.function = nfc_hci_cmd_timeout;
  
  	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);
  
  	del_timer_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");
  