// SPDX-License-Identifier: GPL-2.0-only

  /*
   * HCI based Driver for STMicroelectronics NFC Chip
   *
   * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.

   */

  #include <linux/module.h>

  #include <linux/nfc.h>
  #include <net/nfc/hci.h>
  #include <net/nfc/llc.h>

  #include "st21nfca.h"

  
  #define DRIVER_DESC "HCI NFC driver for ST21NFCA"
  
  #define FULL_VERSION_LEN 3
  
  /* Proprietary gates, events, commands and registers */
  
  /* Commands that apply to all RF readers */
  #define ST21NFCA_RF_READER_CMD_PRESENCE_CHECK	0x30
  
  #define ST21NFCA_RF_READER_ISO15693_GATE	0x12

  #define ST21NFCA_RF_READER_ISO15693_INVENTORY	0x01

  
  /*
   * Reader gate for communication with contact-less cards using Type A
   * protocol ISO14443-3 but not compliant with ISO14443-4
   */
  #define ST21NFCA_RF_READER_14443_3_A_GATE	0x15
  #define ST21NFCA_RF_READER_14443_3_A_UID	0x02
  #define ST21NFCA_RF_READER_14443_3_A_ATQA	0x03
  #define ST21NFCA_RF_READER_14443_3_A_SAK	0x04

  #define ST21NFCA_RF_READER_F_DATARATE		0x01
  #define ST21NFCA_RF_READER_F_DATARATE_106	0x01
  #define ST21NFCA_RF_READER_F_DATARATE_212	0x02
  #define ST21NFCA_RF_READER_F_DATARATE_424	0x04
  #define ST21NFCA_RF_READER_F_POL_REQ		0x02
  #define ST21NFCA_RF_READER_F_POL_REQ_DEFAULT	0xffff0000
  #define ST21NFCA_RF_READER_F_NFCID2		0x03
  #define ST21NFCA_RF_READER_F_NFCID1		0x04
  
  #define ST21NFCA_RF_CARD_F_MODE			0x01
  #define ST21NFCA_RF_CARD_F_NFCID2_LIST		0x04
  #define ST21NFCA_RF_CARD_F_NFCID1		0x05
  #define ST21NFCA_RF_CARD_F_SENS_RES		0x06
  #define ST21NFCA_RF_CARD_F_SEL_RES		0x07
  #define ST21NFCA_RF_CARD_F_DATARATE		0x08
  #define ST21NFCA_RF_CARD_F_DATARATE_212_424	0x01

  #define ST21NFCA_DEVICE_MGNT_PIPE		0x02

  #define ST21NFCA_DM_GETINFO			0x13
  #define ST21NFCA_DM_GETINFO_PIPE_LIST		0x02
  #define ST21NFCA_DM_GETINFO_PIPE_INFO		0x01
  #define ST21NFCA_DM_PIPE_CREATED		0x02
  #define ST21NFCA_DM_PIPE_OPEN			0x04
  #define ST21NFCA_DM_RF_ACTIVE			0x80
  #define ST21NFCA_DM_DISCONNECT			0x30

  
  #define ST21NFCA_DM_IS_PIPE_OPEN(p) \
  	((p & 0x0f) == (ST21NFCA_DM_PIPE_CREATED | ST21NFCA_DM_PIPE_OPEN))

  #define ST21NFCA_NFC_MODE			0x03	/* NFC_MODE parameter*/

  #define ST21NFCA_EVT_HOT_PLUG			0x03
  #define ST21NFCA_EVT_HOT_PLUG_IS_INHIBITED(x) (x->data[0] & 0x80)
  
  #define ST21NFCA_SE_TO_PIPES			2000

  static DECLARE_BITMAP(dev_mask, ST21NFCA_NUM_DEVICES);
  
  static struct nfc_hci_gate st21nfca_gates[] = {

  	{NFC_HCI_ADMIN_GATE, NFC_HCI_ADMIN_PIPE},

  	{NFC_HCI_LINK_MGMT_GATE, NFC_HCI_LINK_MGMT_PIPE},
  	{ST21NFCA_DEVICE_MGNT_GATE, ST21NFCA_DEVICE_MGNT_PIPE},

  	{NFC_HCI_LOOPBACK_GATE, NFC_HCI_INVALID_PIPE},
  	{NFC_HCI_ID_MGMT_GATE, NFC_HCI_INVALID_PIPE},

  	{NFC_HCI_RF_READER_B_GATE, NFC_HCI_INVALID_PIPE},
  	{NFC_HCI_RF_READER_A_GATE, NFC_HCI_INVALID_PIPE},

  	{ST21NFCA_RF_READER_F_GATE, NFC_HCI_INVALID_PIPE},
  	{ST21NFCA_RF_READER_14443_3_A_GATE, NFC_HCI_INVALID_PIPE},

  	{ST21NFCA_RF_READER_ISO15693_GATE, NFC_HCI_INVALID_PIPE},

  	{ST21NFCA_RF_CARD_F_GATE, NFC_HCI_INVALID_PIPE},

  
  	/* Secure element pipes are created by secure element host */
  	{ST21NFCA_CONNECTIVITY_GATE, NFC_HCI_DO_NOT_CREATE_PIPE},
  	{ST21NFCA_APDU_READER_GATE, NFC_HCI_DO_NOT_CREATE_PIPE},

  };

  
  struct st21nfca_pipe_info {
  	u8 pipe_state;
  	u8 src_host_id;
  	u8 src_gate_id;
  	u8 dst_host_id;
  	u8 dst_gate_id;

  } __packed;

  /* Largest headroom needed for outgoing custom commands */
  #define ST21NFCA_CMDS_HEADROOM  7

  static int st21nfca_hci_load_session(struct nfc_hci_dev *hdev)
  {
  	int i, j, r;
  	struct sk_buff *skb_pipe_list, *skb_pipe_info;
  	struct st21nfca_pipe_info *info;
  
  	u8 pipe_list[] = { ST21NFCA_DM_GETINFO_PIPE_LIST,
  		NFC_HCI_TERMINAL_HOST_ID
  	};
  	u8 pipe_info[] = { ST21NFCA_DM_GETINFO_PIPE_INFO,
  		NFC_HCI_TERMINAL_HOST_ID, 0
  	};

  	/* On ST21NFCA device pipes number are dynamics
  	 * A maximum of 16 pipes can be created at the same time
  	 * If pipes are already created, hci_dev_up will fail.
  	 * Doing a clear all pipe is a bad idea because:
  	 * - It does useless EEPROM cycling
  	 * - It might cause issue for secure elements support
  	 * (such as removing connectivity or APDU reader pipe)
  	 * A better approach on ST21NFCA is to:
  	 * - get a pipe list for each host.
  	 * (eg: NFC_HCI_HOST_CONTROLLER_ID for now).
  	 * (TODO Later on UICC HOST and eSE HOST)
  	 * - get pipe information
  	 * - match retrieved pipe list in st21nfca_gates
  	 * ST21NFCA_DEVICE_MGNT_GATE is a proprietary gate
  	 * with ST21NFCA_DEVICE_MGNT_PIPE.
  	 * Pipe can be closed and need to be open.
  	 */
  	r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,

  				ST21NFCA_DEVICE_MGNT_GATE,
  				ST21NFCA_DEVICE_MGNT_PIPE);

  	if (r < 0)

  		return r;

  
  	/* Get pipe list */
  	r = nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
  			ST21NFCA_DM_GETINFO, pipe_list, sizeof(pipe_list),
  			&skb_pipe_list);
  	if (r < 0)

  		return r;

  
  	/* Complete the existing gate_pipe table */
  	for (i = 0; i < skb_pipe_list->len; i++) {
  		pipe_info[2] = skb_pipe_list->data[i];
  		r = nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
  					ST21NFCA_DM_GETINFO, pipe_info,
  					sizeof(pipe_info), &skb_pipe_info);

  		if (r)
  			continue;
  
  		/*
  		 * Match pipe ID and gate ID
  		 * Output format from ST21NFC_DM_GETINFO is:
  		 * - pipe state (1byte)
  		 * - source hid (1byte)
  		 * - source gid (1byte)
  		 * - destination hid (1byte)
  		 * - destination gid (1byte)
  		 */

  		info = (struct st21nfca_pipe_info *) skb_pipe_info->data;

  		if (info->dst_gate_id == ST21NFCA_APDU_READER_GATE &&

  			info->src_host_id == NFC_HCI_UICC_HOST_ID) {

  			pr_err("Unexpected apdu_reader pipe on host %x
  ",
  				info->src_host_id);

  			kfree_skb(skb_pipe_info);

  			continue;
  		}

  		for (j = 3; (j < ARRAY_SIZE(st21nfca_gates)) &&

  			(st21nfca_gates[j].gate != info->dst_gate_id) ; j++)

  			;

  		if (j < ARRAY_SIZE(st21nfca_gates) &&
  			st21nfca_gates[j].gate == info->dst_gate_id &&

  			ST21NFCA_DM_IS_PIPE_OPEN(info->pipe_state)) {

  			hdev->init_data.gates[j].pipe = pipe_info[2];

  			hdev->gate2pipe[st21nfca_gates[j].gate] =

  						pipe_info[2];
  			hdev->pipes[pipe_info[2]].gate =
  						st21nfca_gates[j].gate;
  			hdev->pipes[pipe_info[2]].dest_host =
  						info->src_host_id;

  		}

  		kfree_skb(skb_pipe_info);

  	}

  
  	/*

  	 * 3 gates have a well known pipe ID. Only NFC_HCI_LINK_MGMT_GATE
  	 * is not yet open at this stage.

  	 */

  	r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
  				 NFC_HCI_LINK_MGMT_GATE,
  				 NFC_HCI_LINK_MGMT_PIPE);

  	kfree_skb(skb_pipe_list);
  	return r;
  }

  static int st21nfca_hci_open(struct nfc_hci_dev *hdev)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  	int r;
  
  	mutex_lock(&info->info_lock);
  
  	if (info->state != ST21NFCA_ST_COLD) {
  		r = -EBUSY;
  		goto out;
  	}
  
  	r = info->phy_ops->enable(info->phy_id);
  
  	if (r == 0)
  		info->state = ST21NFCA_ST_READY;
  
  out:
  	mutex_unlock(&info->info_lock);
  	return r;
  }
  
  static void st21nfca_hci_close(struct nfc_hci_dev *hdev)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  
  	mutex_lock(&info->info_lock);
  
  	if (info->state == ST21NFCA_ST_COLD)
  		goto out;
  
  	info->phy_ops->disable(info->phy_id);
  	info->state = ST21NFCA_ST_COLD;
  
  out:
  	mutex_unlock(&info->info_lock);
  }
  
  static int st21nfca_hci_ready(struct nfc_hci_dev *hdev)
  {

  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

  	struct sk_buff *skb;
  
  	u8 param;

  	u8 white_list[2];
  	int wl_size = 0;

  	int r;

  	if (info->se_status->is_uicc_present)

  		white_list[wl_size++] = NFC_HCI_UICC_HOST_ID;

  	if (info->se_status->is_ese_present)

  		white_list[wl_size++] = ST21NFCA_ESE_HOST_ID;

  
  	if (wl_size) {
  		r = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,
  					NFC_HCI_ADMIN_WHITELIST,
  					(u8 *) &white_list, wl_size);
  		if (r < 0)
  			return r;
  	}

  
  	/* Set NFC_MODE in device management gate to enable */
  	r = nfc_hci_get_param(hdev, ST21NFCA_DEVICE_MGNT_GATE,
  			      ST21NFCA_NFC_MODE, &skb);
  	if (r < 0)
  		return r;

  	param = skb->data[0];
  	kfree_skb(skb);
  	if (param == 0) {

  		param = 1;
  
  		r = nfc_hci_set_param(hdev, ST21NFCA_DEVICE_MGNT_GATE,
  					ST21NFCA_NFC_MODE, &param, 1);
  		if (r < 0)
  			return r;
  	}
  
  	r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
  			       NFC_HCI_EVT_END_OPERATION, NULL, 0);
  	if (r < 0)
  		return r;
  
  	r = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,
  			      NFC_HCI_ID_MGMT_VERSION_SW, &skb);
  	if (r < 0)
  		return r;
  
  	if (skb->len != FULL_VERSION_LEN) {
  		kfree_skb(skb);
  		return -EINVAL;
  	}
  
  	print_hex_dump(KERN_DEBUG, "FULL VERSION SOFTWARE INFO: ",
  		       DUMP_PREFIX_NONE, 16, 1,
  		       skb->data, FULL_VERSION_LEN, false);
  
  	kfree_skb(skb);
  
  	return 0;
  }
  
  static int st21nfca_hci_xmit(struct nfc_hci_dev *hdev, struct sk_buff *skb)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  
  	return info->phy_ops->write(info->phy_id, skb);
  }
  
  static int st21nfca_hci_start_poll(struct nfc_hci_dev *hdev,
  				   u32 im_protocols, u32 tm_protocols)
  {
  	int r;

  	u32 pol_req;
  	u8 param[19];
  	struct sk_buff *datarate_skb;

  
  	pr_info(DRIVER_DESC ": %s protocols 0x%x 0x%x
  ",
  		__func__, im_protocols, tm_protocols);
  
  	r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
  			       NFC_HCI_EVT_END_OPERATION, NULL, 0);
  	if (r < 0)
  		return r;
  	if (im_protocols) {
  		/*
  		 * enable polling according to im_protocols & tm_protocols
  		 * - CLOSE pipe according to im_protocols & tm_protocols
  		 */
  		if ((NFC_HCI_RF_READER_B_GATE & im_protocols) == 0) {
  			r = nfc_hci_disconnect_gate(hdev,
  					NFC_HCI_RF_READER_B_GATE);
  			if (r < 0)
  				return r;
  		}
  
  		if ((NFC_HCI_RF_READER_A_GATE & im_protocols) == 0) {
  			r = nfc_hci_disconnect_gate(hdev,
  					NFC_HCI_RF_READER_A_GATE);
  			if (r < 0)
  				return r;
  		}
  
  		if ((ST21NFCA_RF_READER_F_GATE & im_protocols) == 0) {
  			r = nfc_hci_disconnect_gate(hdev,
  					ST21NFCA_RF_READER_F_GATE);
  			if (r < 0)
  				return r;

  		} else {
  			hdev->gb = nfc_get_local_general_bytes(hdev->ndev,
  							       &hdev->gb_len);
  
  			if (hdev->gb == NULL || hdev->gb_len == 0) {
  				im_protocols &= ~NFC_PROTO_NFC_DEP_MASK;
  				tm_protocols &= ~NFC_PROTO_NFC_DEP_MASK;
  			}
  
  			param[0] = ST21NFCA_RF_READER_F_DATARATE_106 |
  			    ST21NFCA_RF_READER_F_DATARATE_212 |
  			    ST21NFCA_RF_READER_F_DATARATE_424;
  			r = nfc_hci_set_param(hdev, ST21NFCA_RF_READER_F_GATE,
  					      ST21NFCA_RF_READER_F_DATARATE,
  					      param, 1);
  			if (r < 0)
  				return r;

  			pol_req = be32_to_cpu((__force __be32)
  					ST21NFCA_RF_READER_F_POL_REQ_DEFAULT);

  			r = nfc_hci_set_param(hdev, ST21NFCA_RF_READER_F_GATE,
  					      ST21NFCA_RF_READER_F_POL_REQ,
  					      (u8 *) &pol_req, 4);
  			if (r < 0)
  				return r;

  		}
  
  		if ((ST21NFCA_RF_READER_14443_3_A_GATE & im_protocols) == 0) {
  			r = nfc_hci_disconnect_gate(hdev,
  					ST21NFCA_RF_READER_14443_3_A_GATE);
  			if (r < 0)
  				return r;
  		}
  
  		if ((ST21NFCA_RF_READER_ISO15693_GATE & im_protocols) == 0) {
  			r = nfc_hci_disconnect_gate(hdev,
  					ST21NFCA_RF_READER_ISO15693_GATE);
  			if (r < 0)
  				return r;
  		}
  
  		r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
  				       NFC_HCI_EVT_READER_REQUESTED, NULL, 0);
  		if (r < 0)
  			nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
  					   NFC_HCI_EVT_END_OPERATION, NULL, 0);
  	}

  
  	if (tm_protocols & NFC_PROTO_NFC_DEP_MASK) {
  		r = nfc_hci_get_param(hdev, ST21NFCA_RF_CARD_F_GATE,
  				      ST21NFCA_RF_CARD_F_DATARATE,
  				      &datarate_skb);
  		if (r < 0)
  			return r;
  
  		/* Configure the maximum supported datarate to 424Kbps */
  		if (datarate_skb->len > 0 &&
  		    datarate_skb->data[0] !=
  		    ST21NFCA_RF_CARD_F_DATARATE_212_424) {
  			param[0] = ST21NFCA_RF_CARD_F_DATARATE_212_424;
  			r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
  					      ST21NFCA_RF_CARD_F_DATARATE,
  					      param, 1);

  			if (r < 0) {
  				kfree_skb(datarate_skb);

  				return r;

  			}

  		}

  		kfree_skb(datarate_skb);

  
  		/*
  		 * Configure sens_res
  		 *
  		 * NFC Forum Digital Spec Table 7:
  		 * NFCID1 size: triple (10 bytes)
  		 */
  		param[0] = 0x00;
  		param[1] = 0x08;
  		r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
  				      ST21NFCA_RF_CARD_F_SENS_RES, param, 2);
  		if (r < 0)
  			return r;
  
  		/*
  		 * Configure sel_res
  		 *
  		 * NFC Forum Digistal Spec Table 17:
  		 * b3 set to 0b (value b7-b6):
  		 * - 10b: Configured for NFC-DEP Protocol
  		 */
  		param[0] = 0x40;
  		r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
  				      ST21NFCA_RF_CARD_F_SEL_RES, param, 1);
  		if (r < 0)
  			return r;
  
  		/* Configure NFCID1 Random uid */
  		r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
  				      ST21NFCA_RF_CARD_F_NFCID1, NULL, 0);
  		if (r < 0)
  			return r;
  
  		/* Configure NFCID2_LIST */
  		/* System Code */
  		param[0] = 0x00;
  		param[1] = 0x00;
  		/* NFCID2 */
  		param[2] = 0x01;
  		param[3] = 0xfe;
  		param[4] = 'S';
  		param[5] = 'T';
  		param[6] = 'M';
  		param[7] = 'i';
  		param[8] = 'c';
  		param[9] = 'r';
  		/* 8 byte Pad bytes used for polling respone frame */
  
  		/*
  		 * Configuration byte:
  		 * - bit 0: define the default NFCID2 entry used when the
  		 * system code is equal to 'FFFF'
  		 * - bit 1: use a random value for lowest 6 bytes of
  		 * NFCID2 value
  		 * - bit 2: ignore polling request frame if request code
  		 * is equal to '01'
  		 * - Other bits are RFU
  		 */
  		param[18] = 0x01;
  		r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
  				      ST21NFCA_RF_CARD_F_NFCID2_LIST, param,
  				      19);
  		if (r < 0)
  			return r;
  
  		param[0] = 0x02;
  		r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
  				      ST21NFCA_RF_CARD_F_MODE, param, 1);
  	}

  	return r;
  }

  static void st21nfca_hci_stop_poll(struct nfc_hci_dev *hdev)
  {
  	nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
  			ST21NFCA_DM_DISCONNECT, NULL, 0, NULL);
  }

  static int st21nfca_get_iso14443_3_atqa(struct nfc_hci_dev *hdev, u16 *atqa)
  {
  	int r;
  	struct sk_buff *atqa_skb = NULL;
  
  	r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_14443_3_A_GATE,
  			      ST21NFCA_RF_READER_14443_3_A_ATQA, &atqa_skb);
  	if (r < 0)
  		goto exit;
  
  	if (atqa_skb->len != 2) {
  		r = -EPROTO;
  		goto exit;
  	}

  	*atqa = be16_to_cpu(*(__be16 *) atqa_skb->data);

  
  exit:
  	kfree_skb(atqa_skb);
  	return r;
  }
  
  static int st21nfca_get_iso14443_3_sak(struct nfc_hci_dev *hdev, u8 *sak)
  {
  	int r;
  	struct sk_buff *sak_skb = NULL;
  
  	r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_14443_3_A_GATE,
  			      ST21NFCA_RF_READER_14443_3_A_SAK, &sak_skb);
  	if (r < 0)
  		goto exit;
  
  	if (sak_skb->len != 1) {
  		r = -EPROTO;
  		goto exit;
  	}
  
  	*sak = sak_skb->data[0];
  
  exit:
  	kfree_skb(sak_skb);
  	return r;
  }

  static int st21nfca_get_iso14443_3_uid(struct nfc_hci_dev *hdev, u8 *uid,

  				       int *len)
  {
  	int r;
  	struct sk_buff *uid_skb = NULL;
  
  	r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_14443_3_A_GATE,
  			      ST21NFCA_RF_READER_14443_3_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(uid, uid_skb->data, uid_skb->len);

  	*len = uid_skb->len;
  exit:
  	kfree_skb(uid_skb);
  	return r;
  }

  static int st21nfca_get_iso15693_inventory(struct nfc_hci_dev *hdev,
  					   struct nfc_target *target)
  {
  	int r;
  	struct sk_buff *inventory_skb = NULL;
  
  	r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_ISO15693_GATE,
  			      ST21NFCA_RF_READER_ISO15693_INVENTORY,
  			      &inventory_skb);
  	if (r < 0)
  		goto exit;
  
  	skb_pull(inventory_skb, 2);
  
  	if (inventory_skb->len == 0 ||
  	    inventory_skb->len > NFC_ISO15693_UID_MAXSIZE) {
  		r = -EPROTO;
  		goto exit;
  	}
  
  	memcpy(target->iso15693_uid, inventory_skb->data, inventory_skb->len);
  	target->iso15693_dsfid	= inventory_skb->data[1];
  	target->is_iso15693 = 1;
  exit:
  	kfree_skb(inventory_skb);
  	return r;
  }

  static int st21nfca_hci_dep_link_up(struct nfc_hci_dev *hdev,
  				    struct nfc_target *target, u8 comm_mode,
  				    u8 *gb, size_t gb_len)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  
  	info->dep_info.idx = target->idx;
  	return st21nfca_im_send_atr_req(hdev, gb, gb_len);
  }
  
  static int st21nfca_hci_dep_link_down(struct nfc_hci_dev *hdev)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  
  	info->state = ST21NFCA_ST_READY;
  
  	return nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
  				ST21NFCA_DM_DISCONNECT, NULL, 0, NULL);
  }

  static int st21nfca_hci_target_from_gate(struct nfc_hci_dev *hdev, u8 gate,
  					 struct nfc_target *target)
  {
  	int r, len;
  	u16 atqa;
  	u8 sak;
  	u8 uid[NFC_NFCID1_MAXSIZE];
  
  	switch (gate) {
  	case ST21NFCA_RF_READER_F_GATE:
  		target->supported_protocols = NFC_PROTO_FELICA_MASK;
  		break;
  	case ST21NFCA_RF_READER_14443_3_A_GATE:
  		/* ISO14443-3 type 1 or 2 tags */
  		r = st21nfca_get_iso14443_3_atqa(hdev, &atqa);
  		if (r < 0)
  			return r;
  		if (atqa == 0x000c) {
  			target->supported_protocols = NFC_PROTO_JEWEL_MASK;
  			target->sens_res = 0x0c00;
  		} else {
  			r = st21nfca_get_iso14443_3_sak(hdev, &sak);
  			if (r < 0)
  				return r;
  
  			r = st21nfca_get_iso14443_3_uid(hdev, uid, &len);
  			if (r < 0)
  				return r;
  
  			target->supported_protocols =
  			    nfc_hci_sak_to_protocol(sak);
  			if (target->supported_protocols == 0xffffffff)
  				return -EPROTO;
  
  			target->sens_res = atqa;
  			target->sel_res = sak;
  			memcpy(target->nfcid1, uid, len);
  			target->nfcid1_len = len;
  		}
  
  		break;

  	case ST21NFCA_RF_READER_ISO15693_GATE:
  		target->supported_protocols = NFC_PROTO_ISO15693_MASK;
  		r = st21nfca_get_iso15693_inventory(hdev, target);
  		if (r < 0)
  			return r;
  		break;

  	default:
  		return -EPROTO;
  	}
  
  	return 0;
  }

  static int st21nfca_hci_complete_target_discovered(struct nfc_hci_dev *hdev,
  						u8 gate,
  						struct nfc_target *target)
  {
  	int r;

  	struct sk_buff *nfcid_skb = NULL;

  
  	if (gate == ST21NFCA_RF_READER_F_GATE) {
  		r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_F_GATE,

  				ST21NFCA_RF_READER_F_NFCID2, &nfcid_skb);

  		if (r < 0)
  			goto exit;

  		if (nfcid_skb->len > NFC_SENSF_RES_MAXSIZE) {

  			r = -EPROTO;
  			goto exit;
  		}
  
  		/*
  		 * - After the recepton of polling response for type F frame
  		 * at 212 or 424 Kbit/s, NFCID2 registry parameters will be
  		 * updated.
  		 * - After the reception of SEL_RES with NFCIP-1 compliant bit
  		 * set for type A frame NFCID1 will be updated
  		 */

  		if (nfcid_skb->len > 0) {

  			/* P2P in type F */

  			memcpy(target->sensf_res, nfcid_skb->data,
  				nfcid_skb->len);
  			target->sensf_res_len = nfcid_skb->len;

  			/* NFC Forum Digital Protocol Table 44 */
  			if (target->sensf_res[0] == 0x01 &&
  			    target->sensf_res[1] == 0xfe)
  				target->supported_protocols =
  							NFC_PROTO_NFC_DEP_MASK;
  			else
  				target->supported_protocols =
  							NFC_PROTO_FELICA_MASK;
  		} else {

  			kfree_skb(nfcid_skb);

  			nfcid_skb = NULL;

  			/* P2P in type A */
  			r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_F_GATE,
  					ST21NFCA_RF_READER_F_NFCID1,

  					&nfcid_skb);

  			if (r < 0)
  				goto exit;

  			if (nfcid_skb->len > NFC_NFCID1_MAXSIZE) {

  				r = -EPROTO;
  				goto exit;
  			}

  			memcpy(target->sensf_res, nfcid_skb->data,
  				nfcid_skb->len);
  			target->sensf_res_len = nfcid_skb->len;

  			target->supported_protocols = NFC_PROTO_NFC_DEP_MASK;
  		}
  		target->hci_reader_gate = ST21NFCA_RF_READER_F_GATE;
  	}
  	r = 1;
  exit:

  	kfree_skb(nfcid_skb);

  	return r;
  }

  #define ST21NFCA_CB_TYPE_READER_ISO15693 1
  static void st21nfca_hci_data_exchange_cb(void *context, struct sk_buff *skb,
  					  int err)
  {
  	struct st21nfca_hci_info *info = context;
  
  	switch (info->async_cb_type) {
  	case ST21NFCA_CB_TYPE_READER_ISO15693:
  		if (err == 0)
  			skb_trim(skb, skb->len - 1);
  		info->async_cb(info->async_cb_context, skb, err);
  		break;
  	default:
  		if (err == 0)
  			kfree_skb(skb);
  		break;
  	}
  }

  /*
   * Returns:
   * <= 0: driver handled the data exchange
   *    1: driver doesn't especially handle, please do standard processing
   */
  static int st21nfca_hci_im_transceive(struct nfc_hci_dev *hdev,
  				      struct nfc_target *target,
  				      struct sk_buff *skb,
  				      data_exchange_cb_t cb, void *cb_context)
  {

  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

  	pr_info(DRIVER_DESC ": %s for gate=%d len=%d
  ", __func__,
  		target->hci_reader_gate, skb->len);
  
  	switch (target->hci_reader_gate) {
  	case ST21NFCA_RF_READER_F_GATE:

  		if (target->supported_protocols == NFC_PROTO_NFC_DEP_MASK)
  			return st21nfca_im_send_dep_req(hdev, skb);

  		*(u8 *)skb_push(skb, 1) = 0x1a;

  		return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
  					      ST21NFCA_WR_XCHG_DATA, skb->data,
  					      skb->len, cb, cb_context);
  	case ST21NFCA_RF_READER_14443_3_A_GATE:

  		*(u8 *)skb_push(skb, 1) = 0x1a;	/* CTR, see spec:10.2.2.1 */

  
  		return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
  					      ST21NFCA_WR_XCHG_DATA, skb->data,
  					      skb->len, cb, cb_context);

  	case ST21NFCA_RF_READER_ISO15693_GATE:
  		info->async_cb_type = ST21NFCA_CB_TYPE_READER_ISO15693;
  		info->async_cb = cb;
  		info->async_cb_context = cb_context;

  		*(u8 *)skb_push(skb, 1) = 0x17;

  
  		return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
  					      ST21NFCA_WR_XCHG_DATA, skb->data,
  					      skb->len,
  					      st21nfca_hci_data_exchange_cb,
  					      info);

  	default:
  		return 1;
  	}
  }

  static int st21nfca_hci_tm_send(struct nfc_hci_dev *hdev, struct sk_buff *skb)
  {
  	return st21nfca_tm_send_dep_res(hdev, skb);
  }

  static int st21nfca_hci_check_presence(struct nfc_hci_dev *hdev,
  				       struct nfc_target *target)
  {
  	u8 fwi = 0x11;

  	switch (target->hci_reader_gate) {
  	case NFC_HCI_RF_READER_A_GATE:
  	case NFC_HCI_RF_READER_B_GATE:
  		/*
  		 * PRESENCE_CHECK on those gates is available
  		 * However, the answer to this command is taking 3 * fwi
  		 * if the card is no present.
  		 * Instead, we send an empty I-Frame with a very short
  		 * configurable fwi ~604µs.
  		 */
  		return nfc_hci_send_cmd(hdev, target->hci_reader_gate,
  					ST21NFCA_WR_XCHG_DATA, &fwi, 1, NULL);
  	case ST21NFCA_RF_READER_14443_3_A_GATE:
  		return nfc_hci_send_cmd(hdev, target->hci_reader_gate,
  					ST21NFCA_RF_READER_CMD_PRESENCE_CHECK,
  					NULL, 0, NULL);
  	default:
  		return -EOPNOTSUPP;
  	}
  }

  static void st21nfca_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
  				struct sk_buff *skb)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  	u8 gate = hdev->pipes[pipe].gate;
  
  	pr_debug("cmd: %x
  ", cmd);
  
  	switch (cmd) {
  	case NFC_HCI_ANY_OPEN_PIPE:
  		if (gate != ST21NFCA_APDU_READER_GATE &&
  			hdev->pipes[pipe].dest_host != NFC_HCI_UICC_HOST_ID)
  			info->se_info.count_pipes++;
  
  		if (info->se_info.count_pipes == info->se_info.expected_pipes) {
  			del_timer_sync(&info->se_info.se_active_timer);
  			info->se_info.se_active = false;
  			info->se_info.count_pipes = 0;
  			complete(&info->se_info.req_completion);
  		}
  	break;
  	}
  }
  
  static int st21nfca_admin_event_received(struct nfc_hci_dev *hdev, u8 event,
  					struct sk_buff *skb)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
  
  	pr_debug("admin event: %x
  ", event);
  
  	switch (event) {
  	case ST21NFCA_EVT_HOT_PLUG:
  		if (info->se_info.se_active) {
  			if (!ST21NFCA_EVT_HOT_PLUG_IS_INHIBITED(skb)) {
  				del_timer_sync(&info->se_info.se_active_timer);
  				info->se_info.se_active = false;
  				complete(&info->se_info.req_completion);
  			} else {
  				mod_timer(&info->se_info.se_active_timer,
  					jiffies +
  					msecs_to_jiffies(ST21NFCA_SE_TO_PIPES));
  			}
  		}
  	break;

  	default:
  		nfc_err(&hdev->ndev->dev, "Unexpected event on admin gate
  ");

  	}
  	kfree_skb(skb);
  	return 0;
  }

  /*
   * Returns:
   * <= 0: driver handled the event, skb consumed
   *    1: driver does not handle the event, please do standard processing
   */

  static int st21nfca_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe,

  				       u8 event, struct sk_buff *skb)
  {

  	u8 gate = hdev->pipes[pipe].gate;
  	u8 host = hdev->pipes[pipe].dest_host;

  	pr_debug("hci event: %d gate: %x
  ", event, gate);

  	switch (gate) {

  	case NFC_HCI_ADMIN_GATE:
  		return st21nfca_admin_event_received(hdev, event, skb);

  	case ST21NFCA_RF_CARD_F_GATE:
  		return st21nfca_dep_event_received(hdev, event, skb);

  	case ST21NFCA_CONNECTIVITY_GATE:
  		return st21nfca_connectivity_event_received(hdev, host,
  							event, skb);
  	case ST21NFCA_APDU_READER_GATE:
  		return st21nfca_apdu_reader_event_received(hdev, event, skb);

  	case NFC_HCI_LOOPBACK_GATE:
  		return st21nfca_hci_loopback_event_received(hdev, event, skb);

  	default:
  		return 1;
  	}

  }

  static struct nfc_hci_ops st21nfca_hci_ops = {
  	.open = st21nfca_hci_open,
  	.close = st21nfca_hci_close,

  	.load_session = st21nfca_hci_load_session,

  	.hci_ready = st21nfca_hci_ready,
  	.xmit = st21nfca_hci_xmit,
  	.start_poll = st21nfca_hci_start_poll,

  	.stop_poll = st21nfca_hci_stop_poll,

  	.dep_link_up = st21nfca_hci_dep_link_up,
  	.dep_link_down = st21nfca_hci_dep_link_down,

  	.target_from_gate = st21nfca_hci_target_from_gate,

  	.complete_target_discovered = st21nfca_hci_complete_target_discovered,

  	.im_transceive = st21nfca_hci_im_transceive,

  	.tm_send = st21nfca_hci_tm_send,

  	.check_presence = st21nfca_hci_check_presence,

  	.event_received = st21nfca_hci_event_received,

  	.cmd_received = st21nfca_hci_cmd_received,
  	.discover_se = st21nfca_hci_discover_se,
  	.enable_se = st21nfca_hci_enable_se,
  	.disable_se = st21nfca_hci_disable_se,
  	.se_io = st21nfca_hci_se_io,

  };
  
  int st21nfca_hci_probe(void *phy_id, struct nfc_phy_ops *phy_ops,
  		       char *llc_name, int phy_headroom, int phy_tailroom,

  		       int phy_payload, struct nfc_hci_dev **hdev,
  			   struct st21nfca_se_status *se_status)

  {
  	struct st21nfca_hci_info *info;
  	int r = 0;
  	int dev_num;
  	u32 protocols;
  	struct nfc_hci_init_data init_data;
  	unsigned long quirks = 0;
  
  	info = kzalloc(sizeof(struct st21nfca_hci_info), GFP_KERNEL);

  	if (!info)
  		return -ENOMEM;

  
  	info->phy_ops = phy_ops;
  	info->phy_id = phy_id;
  	info->state = ST21NFCA_ST_COLD;
  	mutex_init(&info->info_lock);
  
  	init_data.gate_count = ARRAY_SIZE(st21nfca_gates);
  
  	memcpy(init_data.gates, st21nfca_gates, sizeof(st21nfca_gates));
  
  	/*
  	 * Session id must include the driver name + i2c bus addr
  	 * persistent info to discriminate 2 identical chips
  	 */
  	dev_num = find_first_zero_bit(dev_mask, ST21NFCA_NUM_DEVICES);

  	if (dev_num >= ST21NFCA_NUM_DEVICES) {
  		r = -ENODEV;
  		goto err_alloc_hdev;
  	}

  
  	set_bit(dev_num, dev_mask);

  
  	scnprintf(init_data.session_id, sizeof(init_data.session_id), "%s%2x",
  		  "ST21AH", dev_num);
  
  	protocols = NFC_PROTO_JEWEL_MASK |
  	    NFC_PROTO_MIFARE_MASK |
  	    NFC_PROTO_FELICA_MASK |
  	    NFC_PROTO_ISO14443_MASK |

  	    NFC_PROTO_ISO14443_B_MASK |

  	    NFC_PROTO_ISO15693_MASK |
  	    NFC_PROTO_NFC_DEP_MASK;

  
  	set_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &quirks);
  
  	info->hdev =
  	    nfc_hci_allocate_device(&st21nfca_hci_ops, &init_data, quirks,
  				    protocols, llc_name,
  				    phy_headroom + ST21NFCA_CMDS_HEADROOM,
  				    phy_tailroom, phy_payload);
  
  	if (!info->hdev) {
  		pr_err("Cannot allocate nfc hdev.
  ");
  		r = -ENOMEM;
  		goto err_alloc_hdev;
  	}

  	info->se_status = se_status;

  	nfc_hci_set_clientdata(info->hdev, info);
  
  	r = nfc_hci_register_device(info->hdev);
  	if (r)
  		goto err_regdev;
  
  	*hdev = info->hdev;

  	st21nfca_dep_init(info->hdev);

  	st21nfca_se_init(info->hdev);

  	st21nfca_vendor_cmds_init(info->hdev);

  
  	return 0;
  
  err_regdev:
  	nfc_hci_free_device(info->hdev);
  
  err_alloc_hdev:
  	kfree(info);
  
  	return r;
  }
  EXPORT_SYMBOL(st21nfca_hci_probe);
  
  void st21nfca_hci_remove(struct nfc_hci_dev *hdev)
  {
  	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

  	st21nfca_dep_deinit(hdev);

  	st21nfca_se_deinit(hdev);

  	nfc_hci_unregister_device(hdev);
  	nfc_hci_free_device(hdev);
  	kfree(info);
  }
  EXPORT_SYMBOL(st21nfca_hci_remove);
  
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION(DRIVER_DESC);