drivers/nfc/st21nfca/se.c - linux - Git at Google

 // SPDX-License-Identifier: GPL-2.0-only
 /*
  * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
  */

 #include <net/nfc/hci.h>

 #include "st21nfca.h"

 #define ST21NFCA_EVT_UICC_ACTIVATE		0x10
 #define ST21NFCA_EVT_UICC_DEACTIVATE		0x13
 #define ST21NFCA_EVT_SE_HARD_RESET		0x20
 #define ST21NFCA_EVT_SE_SOFT_RESET		0x11
 #define ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER	0x21
 #define ST21NFCA_EVT_SE_ACTIVATE		0x22
 #define ST21NFCA_EVT_SE_DEACTIVATE		0x23

 #define ST21NFCA_EVT_TRANSMIT_DATA		0x10
 #define ST21NFCA_EVT_WTX_REQUEST		0x11

 #define ST21NFCA_EVT_CONNECTIVITY		0x10
 #define ST21NFCA_EVT_TRANSACTION		0x12

 #define ST21NFCA_SE_TO_HOT_PLUG			1000
 /* Connectivity pipe only */
 #define ST21NFCA_SE_COUNT_PIPE_UICC		0x01
 /* Connectivity + APDU Reader pipe */
 #define ST21NFCA_SE_COUNT_PIPE_EMBEDDED	0x02

 #define ST21NFCA_SE_MODE_OFF			0x00
 #define ST21NFCA_SE_MODE_ON				0x01

 #define ST21NFCA_PARAM_ATR				0x01
 #define ST21NFCA_ATR_DEFAULT_BWI		0x04

 /*
  * WT = 2^BWI/10[s], convert into msecs and add a secure
  * room by increasing by 2 this timeout
  */
 #define ST21NFCA_BWI_TO_TIMEOUT(x)		((1 << x) * 200)
 #define ST21NFCA_ATR_GET_Y_FROM_TD(x)	(x >> 4)

 /* If TA is present bit 0 is set */
 #define ST21NFCA_ATR_TA_PRESENT(x) (x & 0x01)
 /* If TB is present bit 1 is set */
 #define ST21NFCA_ATR_TB_PRESENT(x) (x & 0x02)

 static u8 st21nfca_se_get_bwi(struct nfc_hci_dev *hdev)
 {
 	int i;
 	u8 td;
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

 	/* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
 	for (i = 1; i < ST21NFCA_ESE_MAX_LENGTH; i++) {
 		td = ST21NFCA_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
 		if (ST21NFCA_ATR_TA_PRESENT(td))
 			i++;
 		if (ST21NFCA_ATR_TB_PRESENT(td)) {
 			i++;
 			return info->se_info.atr[i] >> 4;
 		}
 	}
 	return ST21NFCA_ATR_DEFAULT_BWI;
 }

 static void st21nfca_se_get_atr(struct nfc_hci_dev *hdev)
 {
 	int r;
 	struct sk_buff *skb;
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

 	r = nfc_hci_get_param(hdev, ST21NFCA_APDU_READER_GATE,
 			ST21NFCA_PARAM_ATR, &skb);
 	if (r < 0)
 		return;

 	if (skb->len <= ST21NFCA_ESE_MAX_LENGTH) {
 		memcpy(info->se_info.atr, skb->data, skb->len);
 		info->se_info.wt_timeout =
 			ST21NFCA_BWI_TO_TIMEOUT(st21nfca_se_get_bwi(hdev));
 	}
 	kfree_skb(skb);
 }

 static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,
 				u8 state)
 {
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 	int r, i;
 	struct sk_buff *sk_host_list;
 	u8 se_event, host_id;

 	switch (se_idx) {
 	case NFC_HCI_UICC_HOST_ID:
 		se_event = (state == ST21NFCA_SE_MODE_ON ?
 					ST21NFCA_EVT_UICC_ACTIVATE :
 					ST21NFCA_EVT_UICC_DEACTIVATE);

 		info->se_info.count_pipes = 0;
 		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_UICC;
 		break;
 	case ST21NFCA_ESE_HOST_ID:
 		se_event = (state == ST21NFCA_SE_MODE_ON ?
 					ST21NFCA_EVT_SE_ACTIVATE :
 					ST21NFCA_EVT_SE_DEACTIVATE);

 		info->se_info.count_pipes = 0;
 		info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_EMBEDDED;
 		break;
 	default:
 		return -EINVAL;
 	}

 	/*
 	 * Wait for an EVT_HOT_PLUG in order to
 	 * retrieve a relevant host list.
 	 */
 	reinit_completion(&info->se_info.req_completion);
 	r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE, se_event,
 			       NULL, 0);
 	if (r < 0)
 		return r;

 	mod_timer(&info->se_info.se_active_timer, jiffies +
 		msecs_to_jiffies(ST21NFCA_SE_TO_HOT_PLUG));
 	info->se_info.se_active = true;

 	/* Ignore return value and check in any case the host_list */
 	wait_for_completion_interruptible(&info->se_info.req_completion);

 	r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
 			NFC_HCI_ADMIN_HOST_LIST,
 			&sk_host_list);
 	if (r < 0)
 		return r;

 	for (i = 0; i < sk_host_list->len &&
 		sk_host_list->data[i] != se_idx; i++)
 		;
 	host_id = sk_host_list->data[i];
 	kfree_skb(sk_host_list);

 	if (state == ST21NFCA_SE_MODE_ON && host_id == se_idx)
 		return se_idx;
 	else if (state == ST21NFCA_SE_MODE_OFF && host_id != se_idx)
 		return se_idx;

 	return -1;
 }

 int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)
 {
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
 	int se_count = 0;

 	if (test_bit(ST21NFCA_FACTORY_MODE, &hdev->quirks))
 		return 0;

 	if (info->se_status->is_uicc_present) {
 		nfc_add_se(hdev->ndev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);
 		se_count++;
 	}

 	if (info->se_status->is_ese_present) {
 		nfc_add_se(hdev->ndev, ST21NFCA_ESE_HOST_ID, NFC_SE_EMBEDDED);
 		se_count++;
 	}

 	return !se_count;
 }
 EXPORT_SYMBOL(st21nfca_hci_discover_se);

 int st21nfca_hci_enable_se(struct nfc_hci_dev *hdev, u32 se_idx)
 {
 	int r;

 	/*
 	 * According to upper layer, se_idx == NFC_SE_UICC when
 	 * info->se_status->is_uicc_enable is true should never happen.
 	 * Same for eSE.
 	 */
 	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_ON);
 	if (r == ST21NFCA_ESE_HOST_ID) {
 		st21nfca_se_get_atr(hdev);
 		r = nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
 				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
 		if (r < 0)
 			return r;
 	} else if (r < 0) {
 		/*
 		 * The activation tentative failed, the secure element
 		 * is not connected. Remove from the list.
 		 */
 		nfc_remove_se(hdev->ndev, se_idx);
 		return r;
 	}

 	return 0;
 }
 EXPORT_SYMBOL(st21nfca_hci_enable_se);

 int st21nfca_hci_disable_se(struct nfc_hci_dev *hdev, u32 se_idx)
 {
 	int r;

 	/*
 	 * According to upper layer, se_idx == NFC_SE_UICC when
 	 * info->se_status->is_uicc_enable is true should never happen
 	 * Same for eSE.
 	 */
 	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_OFF);
 	if (r < 0)
 		return r;

 	return 0;
 }
 EXPORT_SYMBOL(st21nfca_hci_disable_se);

 int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx,
 			u8 *apdu, size_t apdu_length,
 			se_io_cb_t cb, void *cb_context)
 {
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

 	pr_debug("se_io %x\n", se_idx);

 	switch (se_idx) {
 	case ST21NFCA_ESE_HOST_ID:
 		info->se_info.cb = cb;
 		info->se_info.cb_context = cb_context;
 		mod_timer(&info->se_info.bwi_timer, jiffies +
 			  msecs_to_jiffies(info->se_info.wt_timeout));
 		info->se_info.bwi_active = true;
 		return nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
 					ST21NFCA_EVT_TRANSMIT_DATA,
 					apdu, apdu_length);
 	default:
 		/* Need to free cb_context here as at the moment we can't
 		 * clearly indicate to the caller if the callback function
 		 * would be called (and free it) or not. In both cases a
 		 * negative value may be returned to the caller.
 		 */
 		kfree(cb_context);
 		return -ENODEV;
 	}
 }
 EXPORT_SYMBOL(st21nfca_hci_se_io);

 static void st21nfca_se_wt_work(struct work_struct *work)
 {
 	/*
 	 * No answer from the secure element
 	 * within the defined timeout.
 	 * Let's send a reset request as recovery procedure.
 	 * According to the situation, we first try to send a software reset
 	 * to the secure element. If the next command is still not
 	 * answering in time, we send to the CLF a secure element hardware
 	 * reset request.
 	 */
 	/* hardware reset managed through VCC_UICC_OUT power supply */
 	u8 param = 0x01;
 	struct st21nfca_hci_info *info = container_of(work,
 						struct st21nfca_hci_info,
 						se_info.timeout_work);

 	info->se_info.bwi_active = false;

 	if (!info->se_info.xch_error) {
 		info->se_info.xch_error = true;
 		nfc_hci_send_event(info->hdev, ST21NFCA_APDU_READER_GATE,
 				ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
 	} else {
 		info->se_info.xch_error = false;
 		nfc_hci_send_event(info->hdev, ST21NFCA_DEVICE_MGNT_GATE,
 				ST21NFCA_EVT_SE_HARD_RESET, &param, 1);
 	}
 	info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
 }

 static void st21nfca_se_wt_timeout(struct timer_list *t)
 {
 	struct st21nfca_hci_info *info = from_timer(info, t, se_info.bwi_timer);

 	schedule_work(&info->se_info.timeout_work);
 }

 static void st21nfca_se_activation_timeout(struct timer_list *t)
 {
 	struct st21nfca_hci_info *info = from_timer(info, t,
 						    se_info.se_active_timer);

 	info->se_info.se_active = false;

 	complete(&info->se_info.req_completion);
 }

 /*
  * Returns:
  * <= 0: driver handled the event, skb consumed
  *    1: driver does not handle the event, please do standard processing
  */
 int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
 				u8 event, struct sk_buff *skb)
 {
 	int r = 0;
 	struct device *dev = &hdev->ndev->dev;
 	struct nfc_evt_transaction *transaction;
 	u32 aid_len;
 	u8 params_len;

 	pr_debug("connectivity gate event: %x\n", event);

 	switch (event) {
 	case ST21NFCA_EVT_CONNECTIVITY:
 		r = nfc_se_connectivity(hdev->ndev, host);
 	break;
 	case ST21NFCA_EVT_TRANSACTION:
 		/* According to specification etsi 102 622
 		 * 11.2.2.4 EVT_TRANSACTION Table 52
 		 * Description	Tag	Length
 		 * AID		81	5 to 16
 		 * PARAMETERS	82	0 to 255
 		 *
 		 * The key differences are aid storage length is variably sized
 		 * in the packet, but fixed in nfc_evt_transaction, and that the aid_len
 		 * is u8 in the packet, but u32 in the structure, and the tags in
 		 * the packet are not included in nfc_evt_transaction.
 		 *
 		 * size in bytes: 1          1       5-16 1             1           0-255
 		 * offset:        0          1       2    aid_len + 2   aid_len + 3 aid_len + 4
 		 * member name:   aid_tag(M) aid_len aid  params_tag(M) params_len  params
 		 * example:       0x81       5-16    X    0x82 0-255    X
 		 */
 		if (skb->len < 2 || skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
 			return -EPROTO;

 		aid_len = skb->data[1];

 		if (skb->len < aid_len + 4 || aid_len > sizeof(transaction->aid))
 			return -EPROTO;

 		params_len = skb->data[aid_len + 3];

 		/* Verify PARAMETERS tag is (82), and final check that there is enough
 		 * space in the packet to read everything.
 		 */
 		if ((skb->data[aid_len + 2] != NFC_EVT_TRANSACTION_PARAMS_TAG) ||
 		    (skb->len < aid_len + 4 + params_len))
 			return -EPROTO;

 		transaction = devm_kzalloc(dev, sizeof(*transaction) + params_len, GFP_KERNEL);
 		if (!transaction)
 			return -ENOMEM;

 		transaction->aid_len = aid_len;
 		transaction->params_len = params_len;

 		memcpy(transaction->aid, &skb->data[2], aid_len);
 		memcpy(transaction->params, &skb->data[aid_len + 4], params_len);

 		r = nfc_se_transaction(hdev->ndev, host, transaction);
 	break;
 	default:
 		nfc_err(&hdev->ndev->dev, "Unexpected event on connectivity gate\n");
 		return 1;
 	}
 	kfree_skb(skb);
 	return r;
 }
 EXPORT_SYMBOL(st21nfca_connectivity_event_received);

 int st21nfca_apdu_reader_event_received(struct nfc_hci_dev *hdev,
 					u8 event, struct sk_buff *skb)
 {
 	int r = 0;
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

 	pr_debug("apdu reader gate event: %x\n", event);

 	switch (event) {
 	case ST21NFCA_EVT_TRANSMIT_DATA:
 		del_timer_sync(&info->se_info.bwi_timer);
 		cancel_work_sync(&info->se_info.timeout_work);
 		info->se_info.bwi_active = false;
 		r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE,
 				ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
 		if (r < 0)
 			goto exit;

 		info->se_info.cb(info->se_info.cb_context,
 			skb->data, skb->len, 0);
 		break;
 	case ST21NFCA_EVT_WTX_REQUEST:
 		mod_timer(&info->se_info.bwi_timer, jiffies +
 				msecs_to_jiffies(info->se_info.wt_timeout));
 		break;
 	default:
 		nfc_err(&hdev->ndev->dev, "Unexpected event on apdu reader gate\n");
 		return 1;
 	}

 exit:
 	kfree_skb(skb);
 	return r;
 }
 EXPORT_SYMBOL(st21nfca_apdu_reader_event_received);

 void st21nfca_se_init(struct nfc_hci_dev *hdev)
 {
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

 	init_completion(&info->se_info.req_completion);
 	INIT_WORK(&info->se_info.timeout_work, st21nfca_se_wt_work);
 	/* initialize timers */
 	timer_setup(&info->se_info.bwi_timer, st21nfca_se_wt_timeout, 0);
 	info->se_info.bwi_active = false;

 	timer_setup(&info->se_info.se_active_timer,
 		    st21nfca_se_activation_timeout, 0);
 	info->se_info.se_active = false;

 	info->se_info.count_pipes = 0;
 	info->se_info.expected_pipes = 0;

 	info->se_info.xch_error = false;

 	info->se_info.wt_timeout =
 			ST21NFCA_BWI_TO_TIMEOUT(ST21NFCA_ATR_DEFAULT_BWI);
 }
 EXPORT_SYMBOL(st21nfca_se_init);

 void st21nfca_se_deinit(struct nfc_hci_dev *hdev)
 {
 	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

 	if (info->se_info.bwi_active)
 		del_timer_sync(&info->se_info.bwi_timer);
 	if (info->se_info.se_active)
 		del_timer_sync(&info->se_info.se_active_timer);

 	cancel_work_sync(&info->se_info.timeout_work);
 	info->se_info.bwi_active = false;
 	info->se_info.se_active = false;
 }
 EXPORT_SYMBOL(st21nfca_se_deinit);
	// SPDX-License-Identifier: GPL-2.0-only
	/*
	* Copyright (C) 2014 STMicroelectronics SAS. All rights reserved.
	*/

	#include <net/nfc/hci.h>

	#include "st21nfca.h"

	#define ST21NFCA_EVT_UICC_ACTIVATE 0x10
	#define ST21NFCA_EVT_UICC_DEACTIVATE 0x13
	#define ST21NFCA_EVT_SE_HARD_RESET 0x20
	#define ST21NFCA_EVT_SE_SOFT_RESET 0x11
	#define ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER 0x21
	#define ST21NFCA_EVT_SE_ACTIVATE 0x22
	#define ST21NFCA_EVT_SE_DEACTIVATE 0x23

	#define ST21NFCA_EVT_TRANSMIT_DATA 0x10
	#define ST21NFCA_EVT_WTX_REQUEST 0x11

	#define ST21NFCA_EVT_CONNECTIVITY 0x10
	#define ST21NFCA_EVT_TRANSACTION 0x12

	#define ST21NFCA_SE_TO_HOT_PLUG 1000
	/* Connectivity pipe only */
	#define ST21NFCA_SE_COUNT_PIPE_UICC 0x01
	/* Connectivity + APDU Reader pipe */
	#define ST21NFCA_SE_COUNT_PIPE_EMBEDDED 0x02

	#define ST21NFCA_SE_MODE_OFF 0x00
	#define ST21NFCA_SE_MODE_ON 0x01

	#define ST21NFCA_PARAM_ATR 0x01
	#define ST21NFCA_ATR_DEFAULT_BWI 0x04

	/*
	* WT = 2^BWI/10[s], convert into msecs and add a secure
	* room by increasing by 2 this timeout
	*/
	#define ST21NFCA_BWI_TO_TIMEOUT(x) ((1 << x) * 200)
	#define ST21NFCA_ATR_GET_Y_FROM_TD(x) (x >> 4)

	/* If TA is present bit 0 is set */
	#define ST21NFCA_ATR_TA_PRESENT(x) (x & 0x01)
	/* If TB is present bit 1 is set */
	#define ST21NFCA_ATR_TB_PRESENT(x) (x & 0x02)

	static u8 st21nfca_se_get_bwi(struct nfc_hci_dev *hdev)
	{
	int i;
	u8 td;
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

	/* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
	for (i = 1; i < ST21NFCA_ESE_MAX_LENGTH; i++) {
	td = ST21NFCA_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
	if (ST21NFCA_ATR_TA_PRESENT(td))
	i++;
	if (ST21NFCA_ATR_TB_PRESENT(td)) {
	i++;
	return info->se_info.atr[i] >> 4;
	}
	}
	return ST21NFCA_ATR_DEFAULT_BWI;
	}

	static void st21nfca_se_get_atr(struct nfc_hci_dev *hdev)
	{
	int r;
	struct sk_buff *skb;
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

	r = nfc_hci_get_param(hdev, ST21NFCA_APDU_READER_GATE,
	ST21NFCA_PARAM_ATR, &skb);
	if (r < 0)
	return;

	if (skb->len <= ST21NFCA_ESE_MAX_LENGTH) {
	memcpy(info->se_info.atr, skb->data, skb->len);
	info->se_info.wt_timeout =
	ST21NFCA_BWI_TO_TIMEOUT(st21nfca_se_get_bwi(hdev));
	}
	kfree_skb(skb);
	}

	static int st21nfca_hci_control_se(struct nfc_hci_dev *hdev, u32 se_idx,
	u8 state)
	{
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
	int r, i;
	struct sk_buff *sk_host_list;
	u8 se_event, host_id;

	switch (se_idx) {
	case NFC_HCI_UICC_HOST_ID:
	se_event = (state == ST21NFCA_SE_MODE_ON ?
	ST21NFCA_EVT_UICC_ACTIVATE :
	ST21NFCA_EVT_UICC_DEACTIVATE);

	info->se_info.count_pipes = 0;
	info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_UICC;
	break;
	case ST21NFCA_ESE_HOST_ID:
	se_event = (state == ST21NFCA_SE_MODE_ON ?
	ST21NFCA_EVT_SE_ACTIVATE :
	ST21NFCA_EVT_SE_DEACTIVATE);

	info->se_info.count_pipes = 0;
	info->se_info.expected_pipes = ST21NFCA_SE_COUNT_PIPE_EMBEDDED;
	break;
	default:
	return -EINVAL;
	}

	/*
	* Wait for an EVT_HOT_PLUG in order to
	* retrieve a relevant host list.
	*/
	reinit_completion(&info->se_info.req_completion);
	r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE, se_event,
	NULL, 0);
	if (r < 0)
	return r;

	mod_timer(&info->se_info.se_active_timer, jiffies +
	msecs_to_jiffies(ST21NFCA_SE_TO_HOT_PLUG));
	info->se_info.se_active = true;

	/* Ignore return value and check in any case the host_list */
	wait_for_completion_interruptible(&info->se_info.req_completion);

	r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
	NFC_HCI_ADMIN_HOST_LIST,
	&sk_host_list);
	if (r < 0)
	return r;

	for (i = 0; i < sk_host_list->len &&
	sk_host_list->data[i] != se_idx; i++)
	;
	host_id = sk_host_list->data[i];
	kfree_skb(sk_host_list);

	if (state == ST21NFCA_SE_MODE_ON && host_id == se_idx)
	return se_idx;
	else if (state == ST21NFCA_SE_MODE_OFF && host_id != se_idx)
	return se_idx;

	return -1;
	}

	int st21nfca_hci_discover_se(struct nfc_hci_dev *hdev)
	{
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
	int se_count = 0;

	if (test_bit(ST21NFCA_FACTORY_MODE, &hdev->quirks))
	return 0;

	if (info->se_status->is_uicc_present) {
	nfc_add_se(hdev->ndev, NFC_HCI_UICC_HOST_ID, NFC_SE_UICC);
	se_count++;
	}

	if (info->se_status->is_ese_present) {
	nfc_add_se(hdev->ndev, ST21NFCA_ESE_HOST_ID, NFC_SE_EMBEDDED);
	se_count++;
	}

	return !se_count;
	}
	EXPORT_SYMBOL(st21nfca_hci_discover_se);

	int st21nfca_hci_enable_se(struct nfc_hci_dev *hdev, u32 se_idx)
	{
	int r;

	/*
	* According to upper layer, se_idx == NFC_SE_UICC when
	* info->se_status->is_uicc_enable is true should never happen.
	* Same for eSE.
	*/
	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_ON);
	if (r == ST21NFCA_ESE_HOST_ID) {
	st21nfca_se_get_atr(hdev);
	r = nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
	ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
	if (r < 0)
	return r;
	} else if (r < 0) {
	/*
	* The activation tentative failed, the secure element
	* is not connected. Remove from the list.
	*/
	nfc_remove_se(hdev->ndev, se_idx);
	return r;
	}

	return 0;
	}
	EXPORT_SYMBOL(st21nfca_hci_enable_se);

	int st21nfca_hci_disable_se(struct nfc_hci_dev *hdev, u32 se_idx)
	{
	int r;

	/*
	* According to upper layer, se_idx == NFC_SE_UICC when
	* info->se_status->is_uicc_enable is true should never happen
	* Same for eSE.
	*/
	r = st21nfca_hci_control_se(hdev, se_idx, ST21NFCA_SE_MODE_OFF);
	if (r < 0)
	return r;

	return 0;
	}
	EXPORT_SYMBOL(st21nfca_hci_disable_se);

	int st21nfca_hci_se_io(struct nfc_hci_dev *hdev, u32 se_idx,
	u8 *apdu, size_t apdu_length,
	se_io_cb_t cb, void *cb_context)
	{
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

	pr_debug("se_io %x\n", se_idx);

	switch (se_idx) {
	case ST21NFCA_ESE_HOST_ID:
	info->se_info.cb = cb;
	info->se_info.cb_context = cb_context;
	mod_timer(&info->se_info.bwi_timer, jiffies +
	msecs_to_jiffies(info->se_info.wt_timeout));
	info->se_info.bwi_active = true;
	return nfc_hci_send_event(hdev, ST21NFCA_APDU_READER_GATE,
	ST21NFCA_EVT_TRANSMIT_DATA,
	apdu, apdu_length);
	default:
	/* Need to free cb_context here as at the moment we can't
	* clearly indicate to the caller if the callback function
	* would be called (and free it) or not. In both cases a
	* negative value may be returned to the caller.
	*/
	kfree(cb_context);
	return -ENODEV;
	}
	}
	EXPORT_SYMBOL(st21nfca_hci_se_io);

	static void st21nfca_se_wt_work(struct work_struct *work)
	{
	/*
	* No answer from the secure element
	* within the defined timeout.
	* Let's send a reset request as recovery procedure.
	* According to the situation, we first try to send a software reset
	* to the secure element. If the next command is still not
	* answering in time, we send to the CLF a secure element hardware
	* reset request.
	*/
	/* hardware reset managed through VCC_UICC_OUT power supply */
	u8 param = 0x01;
	struct st21nfca_hci_info *info = container_of(work,
	struct st21nfca_hci_info,
	se_info.timeout_work);

	info->se_info.bwi_active = false;

	if (!info->se_info.xch_error) {
	info->se_info.xch_error = true;
	nfc_hci_send_event(info->hdev, ST21NFCA_APDU_READER_GATE,
	ST21NFCA_EVT_SE_SOFT_RESET, NULL, 0);
	} else {
	info->se_info.xch_error = false;
	nfc_hci_send_event(info->hdev, ST21NFCA_DEVICE_MGNT_GATE,
	ST21NFCA_EVT_SE_HARD_RESET, &param, 1);
	}
	info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
	}

	static void st21nfca_se_wt_timeout(struct timer_list *t)
	{
	struct st21nfca_hci_info *info = from_timer(info, t, se_info.bwi_timer);

	schedule_work(&info->se_info.timeout_work);
	}

	static void st21nfca_se_activation_timeout(struct timer_list *t)
	{
	struct st21nfca_hci_info *info = from_timer(info, t,
	se_info.se_active_timer);

	info->se_info.se_active = false;

	complete(&info->se_info.req_completion);
	}

	/*
	* Returns:
	* <= 0: driver handled the event, skb consumed
	* 1: driver does not handle the event, please do standard processing
	*/
	int st21nfca_connectivity_event_received(struct nfc_hci_dev *hdev, u8 host,
	u8 event, struct sk_buff *skb)
	{
	int r = 0;
	struct device *dev = &hdev->ndev->dev;
	struct nfc_evt_transaction *transaction;
	u32 aid_len;
	u8 params_len;

	pr_debug("connectivity gate event: %x\n", event);

	switch (event) {
	case ST21NFCA_EVT_CONNECTIVITY:
	r = nfc_se_connectivity(hdev->ndev, host);
	break;
	case ST21NFCA_EVT_TRANSACTION:
	/* According to specification etsi 102 622
	* 11.2.2.4 EVT_TRANSACTION Table 52
	* Description Tag Length
	* AID 81 5 to 16
	* PARAMETERS 82 0 to 255
	*
	* The key differences are aid storage length is variably sized
	* in the packet, but fixed in nfc_evt_transaction, and that the aid_len
	* is u8 in the packet, but u32 in the structure, and the tags in
	* the packet are not included in nfc_evt_transaction.
	*
	* size in bytes: 1 1 5-16 1 1 0-255
	* offset: 0 1 2 aid_len + 2 aid_len + 3 aid_len + 4
	* member name: aid_tag(M) aid_len aid params_tag(M) params_len params
	* example: 0x81 5-16 X 0x82 0-255 X
	*/
	if (skb->len < 2 \|\| skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
	return -EPROTO;

	aid_len = skb->data[1];

	if (skb->len < aid_len + 4 \|\| aid_len > sizeof(transaction->aid))
	return -EPROTO;

	params_len = skb->data[aid_len + 3];

	/* Verify PARAMETERS tag is (82), and final check that there is enough
	* space in the packet to read everything.
	*/
	if ((skb->data[aid_len + 2] != NFC_EVT_TRANSACTION_PARAMS_TAG) \|\|
	(skb->len < aid_len + 4 + params_len))
	return -EPROTO;

	transaction = devm_kzalloc(dev, sizeof(*transaction) + params_len, GFP_KERNEL);
	if (!transaction)
	return -ENOMEM;

	transaction->aid_len = aid_len;
	transaction->params_len = params_len;

	memcpy(transaction->aid, &skb->data[2], aid_len);
	memcpy(transaction->params, &skb->data[aid_len + 4], params_len);

	r = nfc_se_transaction(hdev->ndev, host, transaction);
	break;
	default:
	nfc_err(&hdev->ndev->dev, "Unexpected event on connectivity gate\n");
	return 1;
	}
	kfree_skb(skb);
	return r;
	}
	EXPORT_SYMBOL(st21nfca_connectivity_event_received);

	int st21nfca_apdu_reader_event_received(struct nfc_hci_dev *hdev,
	u8 event, struct sk_buff *skb)
	{
	int r = 0;
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

	pr_debug("apdu reader gate event: %x\n", event);

	switch (event) {
	case ST21NFCA_EVT_TRANSMIT_DATA:
	del_timer_sync(&info->se_info.bwi_timer);
	cancel_work_sync(&info->se_info.timeout_work);
	info->se_info.bwi_active = false;
	r = nfc_hci_send_event(hdev, ST21NFCA_DEVICE_MGNT_GATE,
	ST21NFCA_EVT_SE_END_OF_APDU_TRANSFER, NULL, 0);
	if (r < 0)
	goto exit;

	info->se_info.cb(info->se_info.cb_context,
	skb->data, skb->len, 0);
	break;
	case ST21NFCA_EVT_WTX_REQUEST:
	mod_timer(&info->se_info.bwi_timer, jiffies +
	msecs_to_jiffies(info->se_info.wt_timeout));
	break;
	default:
	nfc_err(&hdev->ndev->dev, "Unexpected event on apdu reader gate\n");
	return 1;
	}

	exit:
	kfree_skb(skb);
	return r;
	}
	EXPORT_SYMBOL(st21nfca_apdu_reader_event_received);

	void st21nfca_se_init(struct nfc_hci_dev *hdev)
	{
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

	init_completion(&info->se_info.req_completion);
	INIT_WORK(&info->se_info.timeout_work, st21nfca_se_wt_work);
	/* initialize timers */
	timer_setup(&info->se_info.bwi_timer, st21nfca_se_wt_timeout, 0);
	info->se_info.bwi_active = false;

	timer_setup(&info->se_info.se_active_timer,
	st21nfca_se_activation_timeout, 0);
	info->se_info.se_active = false;

	info->se_info.count_pipes = 0;
	info->se_info.expected_pipes = 0;

	info->se_info.xch_error = false;

	info->se_info.wt_timeout =
	ST21NFCA_BWI_TO_TIMEOUT(ST21NFCA_ATR_DEFAULT_BWI);
	}
	EXPORT_SYMBOL(st21nfca_se_init);

	void st21nfca_se_deinit(struct nfc_hci_dev *hdev)
	{
	struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

	if (info->se_info.bwi_active)
	del_timer_sync(&info->se_info.bwi_timer);
	if (info->se_info.se_active)
	del_timer_sync(&info->se_info.se_active_timer);

	cancel_work_sync(&info->se_info.timeout_work);
	info->se_info.bwi_active = false;
	info->se_info.se_active = false;
	}
	EXPORT_SYMBOL(st21nfca_se_deinit);