drivers/nfc/st21nfca/st21nfca.c - kernel/msm-5.4 - Gitiles

 /*
  * HCI based Driver for STMicroelectronics NFC Chip
  *
  * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * 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/>.
  */

 #include <linux/crc-ccitt.h>
 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/miscdevice.h>
 #include <linux/interrupt.h>
 #include <linux/gpio.h>
 #include <linux/i2c.h>

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

 #include <uapi/linux/nfc.h>

 #include "st21nfca.h"
 #include <linux/platform_data/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

 /*
  * 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_DEVICE_MGNT_GATE		0x01
 #define ST21NFCA_DEVICE_MGNT_PIPE		0x02
 #define ST21NFCA_NFC_MODE	0x03	/* NFC_MODE parameter*/


 static DECLARE_BITMAP(dev_mask, ST21NFCA_NUM_DEVICES);

 static struct nfc_hci_gate st21nfca_gates[] = {
 	{NFC_HCI_ADMIN_GATE, NFC_HCI_INVALID_PIPE},
 	{NFC_HCI_LOOPBACK_GATE, NFC_HCI_INVALID_PIPE},
 	{NFC_HCI_ID_MGMT_GATE, NFC_HCI_INVALID_PIPE},
 	{NFC_HCI_LINK_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_DEVICE_MGNT_GATE, ST21NFCA_DEVICE_MGNT_PIPE},
 	{ST21NFCA_RF_READER_F_GATE, NFC_HCI_INVALID_PIPE},
 	{ST21NFCA_RF_READER_14443_3_A_GATE, NFC_HCI_INVALID_PIPE},
 };
 /* Largest headroom needed for outgoing custom commands */
 #define ST21NFCA_CMDS_HEADROOM  7

 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 sk_buff *skb;

 	u8 param;
 	int r;

 	param = NFC_HCI_UICC_HOST_ID;
 	r = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,
 			      NFC_HCI_ADMIN_WHITELIST, &param, 1);
 	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;

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

 	pr_info(DRIVER_DESC ": %s protocols 0x%x 0x%x\n",
 		__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;
 		}

 		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);
 	}
 	return r;
 }

 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(*(u16 *) 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 *gate,
 				       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;
 	}

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

 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;
 	default:
 		return -EPROTO;
 	}

 	return 0;
 }

 /*
  * 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)
 {
 	pr_info(DRIVER_DESC ": %s for gate=%d len=%d\n", __func__,
 		target->hci_reader_gate, skb->len);

 	switch (target->hci_reader_gate) {
 	case ST21NFCA_RF_READER_F_GATE:
 		*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:
 		*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);
 	default:
 		return 1;
 	}
 }

 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 struct nfc_hci_ops st21nfca_hci_ops = {
 	.open = st21nfca_hci_open,
 	.close = st21nfca_hci_close,
 	.hci_ready = st21nfca_hci_ready,
 	.xmit = st21nfca_hci_xmit,
 	.start_poll = st21nfca_hci_start_poll,
 	.target_from_gate = st21nfca_hci_target_from_gate,
 	.im_transceive = st21nfca_hci_im_transceive,
 	.check_presence = st21nfca_hci_check_presence,
 };

 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_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) {
 		r = -ENOMEM;
 		goto err_alloc_hdev;
 	}

 	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)
 		goto err_alloc_hdev;

 	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;

 	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.\n");
 		r = -ENOMEM;
 		goto err_alloc_hdev;
 	}

 	nfc_hci_set_clientdata(info->hdev, info);

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

 	*hdev = 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);

 	nfc_hci_unregister_device(hdev);
 	nfc_hci_free_device(hdev);
 	kfree(info);
 }
 EXPORT_SYMBOL(st21nfca_hci_remove);

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION(DRIVER_DESC);
	/*
	* HCI based Driver for STMicroelectronics NFC Chip
	*
	* Copyright (C) 2014 STMicroelectronics SAS. All rights reserved.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* 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/>.
	*/

	#include <linux/crc-ccitt.h>
	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/slab.h>
	#include <linux/miscdevice.h>
	#include <linux/interrupt.h>
	#include <linux/gpio.h>
	#include <linux/i2c.h>

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

	#include <uapi/linux/nfc.h>

	#include "st21nfca.h"
	#include <linux/platform_data/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

	/*
	* 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_DEVICE_MGNT_GATE 0x01
	#define ST21NFCA_DEVICE_MGNT_PIPE 0x02
	#define ST21NFCA_NFC_MODE 0x03 /* NFC_MODE parameter*/


	static DECLARE_BITMAP(dev_mask, ST21NFCA_NUM_DEVICES);

	static struct nfc_hci_gate st21nfca_gates[] = {
	{NFC_HCI_ADMIN_GATE, NFC_HCI_INVALID_PIPE},
	{NFC_HCI_LOOPBACK_GATE, NFC_HCI_INVALID_PIPE},
	{NFC_HCI_ID_MGMT_GATE, NFC_HCI_INVALID_PIPE},
	{NFC_HCI_LINK_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_DEVICE_MGNT_GATE, ST21NFCA_DEVICE_MGNT_PIPE},
	{ST21NFCA_RF_READER_F_GATE, NFC_HCI_INVALID_PIPE},
	{ST21NFCA_RF_READER_14443_3_A_GATE, NFC_HCI_INVALID_PIPE},
	};
	/* Largest headroom needed for outgoing custom commands */
	#define ST21NFCA_CMDS_HEADROOM 7

	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 sk_buff *skb;

	u8 param;
	int r;

	param = NFC_HCI_UICC_HOST_ID;
	r = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,
	NFC_HCI_ADMIN_WHITELIST, &param, 1);
	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;

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

	pr_info(DRIVER_DESC ": %s protocols 0x%x 0x%x\n",
	__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;
	}

	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);
	}
	return r;
	}

	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((u16 *) 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 gate,
	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;
	}

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

	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;
	default:
	return -EPROTO;
	}

	return 0;
	}

	/*
	* 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)
	{
	pr_info(DRIVER_DESC ": %s for gate=%d len=%d\n", __func__,
	target->hci_reader_gate, skb->len);

	switch (target->hci_reader_gate) {
	case ST21NFCA_RF_READER_F_GATE:
	*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:
	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);
	default:
	return 1;
	}
	}

	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 struct nfc_hci_ops st21nfca_hci_ops = {
	.open = st21nfca_hci_open,
	.close = st21nfca_hci_close,
	.hci_ready = st21nfca_hci_ready,
	.xmit = st21nfca_hci_xmit,
	.start_poll = st21nfca_hci_start_poll,
	.target_from_gate = st21nfca_hci_target_from_gate,
	.im_transceive = st21nfca_hci_im_transceive,
	.check_presence = st21nfca_hci_check_presence,
	};

	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_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) {
	r = -ENOMEM;
	goto err_alloc_hdev;
	}

	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)
	goto err_alloc_hdev;

	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;

	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.\n");
	r = -ENOMEM;
	goto err_alloc_hdev;
	}

	nfc_hci_set_clientdata(info->hdev, info);

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

	*hdev = 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);

	nfc_hci_unregister_device(hdev);
	nfc_hci_free_device(hdev);
	kfree(info);
	}
	EXPORT_SYMBOL(st21nfca_hci_remove);

	MODULE_LICENSE("GPL");
	MODULE_DESCRIPTION(DRIVER_DESC);