drivers/nfc/microread/microread.c - vendor/opensource/backports - Git at Google

 /*
  * HCI based Driver for Inside Secure microread NFC Chip
  *
  * Copyright (C) 2013  Intel Corporation. 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/>.
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/module.h>
 #include <linux/delay.h>
 #include <linux/slab.h>
 #include <linux/crc-ccitt.h>

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

 #include "microread.h"

 /* Proprietary gates, events, commands and registers */
 /* Admin */
 #define MICROREAD_GATE_ID_ADM NFC_HCI_ADMIN_GATE
 #define MICROREAD_GATE_ID_MGT 0x01
 #define MICROREAD_GATE_ID_OS 0x02
 #define MICROREAD_GATE_ID_TESTRF 0x03
 #define MICROREAD_GATE_ID_LOOPBACK NFC_HCI_LOOPBACK_GATE
 #define MICROREAD_GATE_ID_IDT NFC_HCI_ID_MGMT_GATE
 #define MICROREAD_GATE_ID_LMS NFC_HCI_LINK_MGMT_GATE

 /* Reader */
 #define MICROREAD_GATE_ID_MREAD_GEN 0x10
 #define MICROREAD_GATE_ID_MREAD_ISO_B NFC_HCI_RF_READER_B_GATE
 #define MICROREAD_GATE_ID_MREAD_NFC_T1 0x12
 #define MICROREAD_GATE_ID_MREAD_ISO_A NFC_HCI_RF_READER_A_GATE
 #define MICROREAD_GATE_ID_MREAD_NFC_T3 0x14
 #define MICROREAD_GATE_ID_MREAD_ISO_15_3 0x15
 #define MICROREAD_GATE_ID_MREAD_ISO_15_2 0x16
 #define MICROREAD_GATE_ID_MREAD_ISO_B_3 0x17
 #define MICROREAD_GATE_ID_MREAD_BPRIME 0x18
 #define MICROREAD_GATE_ID_MREAD_ISO_A_3 0x19

 /* Card */
 #define MICROREAD_GATE_ID_MCARD_GEN 0x20
 #define MICROREAD_GATE_ID_MCARD_ISO_B 0x21
 #define MICROREAD_GATE_ID_MCARD_BPRIME 0x22
 #define MICROREAD_GATE_ID_MCARD_ISO_A 0x23
 #define MICROREAD_GATE_ID_MCARD_NFC_T3 0x24
 #define MICROREAD_GATE_ID_MCARD_ISO_15_3 0x25
 #define MICROREAD_GATE_ID_MCARD_ISO_15_2 0x26
 #define MICROREAD_GATE_ID_MCARD_ISO_B_2 0x27
 #define MICROREAD_GATE_ID_MCARD_ISO_CUSTOM 0x28
 #define MICROREAD_GATE_ID_SECURE_ELEMENT 0x2F

 /* P2P */
 #define MICROREAD_GATE_ID_P2P_GEN 0x30
 #define MICROREAD_GATE_ID_P2P_TARGET 0x31
 #define MICROREAD_PAR_P2P_TARGET_MODE 0x01
 #define MICROREAD_PAR_P2P_TARGET_GT 0x04
 #define MICROREAD_GATE_ID_P2P_INITIATOR 0x32
 #define MICROREAD_PAR_P2P_INITIATOR_GI 0x01
 #define MICROREAD_PAR_P2P_INITIATOR_GT 0x03

 /* Those pipes are created/opened by default in the chip */
 #define MICROREAD_PIPE_ID_LMS 0x00
 #define MICROREAD_PIPE_ID_ADMIN 0x01
 #define MICROREAD_PIPE_ID_MGT 0x02
 #define MICROREAD_PIPE_ID_OS 0x03
 #define MICROREAD_PIPE_ID_HDS_LOOPBACK 0x04
 #define MICROREAD_PIPE_ID_HDS_IDT 0x05
 #define MICROREAD_PIPE_ID_HDS_MCARD_ISO_B 0x08
 #define MICROREAD_PIPE_ID_HDS_MCARD_ISO_BPRIME 0x09
 #define MICROREAD_PIPE_ID_HDS_MCARD_ISO_A 0x0A
 #define MICROREAD_PIPE_ID_HDS_MCARD_ISO_15_3 0x0B
 #define MICROREAD_PIPE_ID_HDS_MCARD_ISO_15_2 0x0C
 #define MICROREAD_PIPE_ID_HDS_MCARD_NFC_T3 0x0D
 #define MICROREAD_PIPE_ID_HDS_MCARD_ISO_B_2 0x0E
 #define MICROREAD_PIPE_ID_HDS_MCARD_CUSTOM 0x0F
 #define MICROREAD_PIPE_ID_HDS_MREAD_ISO_B 0x10
 #define MICROREAD_PIPE_ID_HDS_MREAD_NFC_T1 0x11
 #define MICROREAD_PIPE_ID_HDS_MREAD_ISO_A 0x12
 #define MICROREAD_PIPE_ID_HDS_MREAD_ISO_15_3 0x13
 #define MICROREAD_PIPE_ID_HDS_MREAD_ISO_15_2 0x14
 #define MICROREAD_PIPE_ID_HDS_MREAD_NFC_T3 0x15
 #define MICROREAD_PIPE_ID_HDS_MREAD_ISO_B_3 0x16
 #define MICROREAD_PIPE_ID_HDS_MREAD_BPRIME 0x17
 #define MICROREAD_PIPE_ID_HDS_MREAD_ISO_A_3 0x18
 #define MICROREAD_PIPE_ID_HDS_MREAD_GEN 0x1B
 #define MICROREAD_PIPE_ID_HDS_STACKED_ELEMENT 0x1C
 #define MICROREAD_PIPE_ID_HDS_INSTANCES 0x1D
 #define MICROREAD_PIPE_ID_HDS_TESTRF 0x1E
 #define MICROREAD_PIPE_ID_HDS_P2P_TARGET 0x1F
 #define MICROREAD_PIPE_ID_HDS_P2P_INITIATOR 0x20

 /* Events */
 #define MICROREAD_EVT_MREAD_DISCOVERY_OCCURED NFC_HCI_EVT_TARGET_DISCOVERED
 #define MICROREAD_EVT_MREAD_CARD_FOUND 0x3D
 #define MICROREAD_EMCF_A_ATQA 0
 #define MICROREAD_EMCF_A_SAK 2
 #define MICROREAD_EMCF_A_LEN 3
 #define MICROREAD_EMCF_A_UID 4
 #define MICROREAD_EMCF_A3_ATQA 0
 #define MICROREAD_EMCF_A3_SAK 2
 #define MICROREAD_EMCF_A3_LEN 3
 #define MICROREAD_EMCF_A3_UID 4
 #define MICROREAD_EMCF_B_UID 0
 #define MICROREAD_EMCF_T1_ATQA 0
 #define MICROREAD_EMCF_T1_UID 4
 #define MICROREAD_EMCF_T3_UID 0
 #define MICROREAD_EVT_MREAD_DISCOVERY_START NFC_HCI_EVT_READER_REQUESTED
 #define MICROREAD_EVT_MREAD_DISCOVERY_START_SOME 0x3E
 #define MICROREAD_EVT_MREAD_DISCOVERY_STOP NFC_HCI_EVT_END_OPERATION
 #define MICROREAD_EVT_MREAD_SIM_REQUESTS 0x3F
 #define MICROREAD_EVT_MCARD_EXCHANGE NFC_HCI_EVT_TARGET_DISCOVERED
 #define MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_TO_RF 0x20
 #define MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_FROM_RF 0x21
 #define MICROREAD_EVT_MCARD_FIELD_ON 0x11
 #define MICROREAD_EVT_P2P_TARGET_ACTIVATED 0x13
 #define MICROREAD_EVT_P2P_TARGET_DEACTIVATED 0x12
 #define MICROREAD_EVT_MCARD_FIELD_OFF 0x14

 /* Commands */
 #define MICROREAD_CMD_MREAD_EXCHANGE 0x10
 #define MICROREAD_CMD_MREAD_SUBSCRIBE 0x3F

 /* Hosts IDs */
 #define MICROREAD_ELT_ID_HDS NFC_HCI_TERMINAL_HOST_ID
 #define MICROREAD_ELT_ID_SIM NFC_HCI_UICC_HOST_ID
 #define MICROREAD_ELT_ID_SE1 0x03
 #define MICROREAD_ELT_ID_SE2 0x04
 #define MICROREAD_ELT_ID_SE3 0x05

 static struct nfc_hci_gate microread_gates[] = {
 	{MICROREAD_GATE_ID_ADM, MICROREAD_PIPE_ID_ADMIN},
 	{MICROREAD_GATE_ID_LOOPBACK, MICROREAD_PIPE_ID_HDS_LOOPBACK},
 	{MICROREAD_GATE_ID_IDT, MICROREAD_PIPE_ID_HDS_IDT},
 	{MICROREAD_GATE_ID_LMS, MICROREAD_PIPE_ID_LMS},
 	{MICROREAD_GATE_ID_MREAD_ISO_B, MICROREAD_PIPE_ID_HDS_MREAD_ISO_B},
 	{MICROREAD_GATE_ID_MREAD_ISO_A, MICROREAD_PIPE_ID_HDS_MREAD_ISO_A},
 	{MICROREAD_GATE_ID_MREAD_ISO_A_3, MICROREAD_PIPE_ID_HDS_MREAD_ISO_A_3},
 	{MICROREAD_GATE_ID_MGT, MICROREAD_PIPE_ID_MGT},
 	{MICROREAD_GATE_ID_OS, MICROREAD_PIPE_ID_OS},
 	{MICROREAD_GATE_ID_MREAD_NFC_T1, MICROREAD_PIPE_ID_HDS_MREAD_NFC_T1},
 	{MICROREAD_GATE_ID_MREAD_NFC_T3, MICROREAD_PIPE_ID_HDS_MREAD_NFC_T3},
 	{MICROREAD_GATE_ID_P2P_TARGET, MICROREAD_PIPE_ID_HDS_P2P_TARGET},
 	{MICROREAD_GATE_ID_P2P_INITIATOR, MICROREAD_PIPE_ID_HDS_P2P_INITIATOR}
 };

 /* Largest headroom needed for outgoing custom commands */
 #define MICROREAD_CMDS_HEADROOM	2
 #define MICROREAD_CMD_TAILROOM	2

 struct microread_info {
 	struct nfc_phy_ops *phy_ops;
 	void *phy_id;

 	struct nfc_hci_dev *hdev;

 	int async_cb_type;
 	data_exchange_cb_t async_cb;
 	void *async_cb_context;
 };

 static int microread_open(struct nfc_hci_dev *hdev)
 {
 	struct microread_info *info = nfc_hci_get_clientdata(hdev);

 	return info->phy_ops->enable(info->phy_id);
 }

 static void microread_close(struct nfc_hci_dev *hdev)
 {
 	struct microread_info *info = nfc_hci_get_clientdata(hdev);

 	info->phy_ops->disable(info->phy_id);
 }

 static int microread_hci_ready(struct nfc_hci_dev *hdev)
 {
 	int r;
 	u8 param[4];

 	param[0] = 0x03;
 	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_ISO_A,
 			     MICROREAD_CMD_MREAD_SUBSCRIBE, param, 1, NULL);
 	if (r)
 		return r;

 	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_ISO_A_3,
 			     MICROREAD_CMD_MREAD_SUBSCRIBE, NULL, 0, NULL);
 	if (r)
 		return r;

 	param[0] = 0x00;
 	param[1] = 0x03;
 	param[2] = 0x00;
 	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_ISO_B,
 			     MICROREAD_CMD_MREAD_SUBSCRIBE, param, 3, NULL);
 	if (r)
 		return r;

 	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_NFC_T1,
 			     MICROREAD_CMD_MREAD_SUBSCRIBE, NULL, 0, NULL);
 	if (r)
 		return r;

 	param[0] = 0xFF;
 	param[1] = 0xFF;
 	param[2] = 0x00;
 	param[3] = 0x00;
 	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_NFC_T3,
 			     MICROREAD_CMD_MREAD_SUBSCRIBE, param, 4, NULL);

 	return r;
 }

 static int microread_xmit(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 {
 	struct microread_info *info = nfc_hci_get_clientdata(hdev);

 	return info->phy_ops->write(info->phy_id, skb);
 }

 static int microread_start_poll(struct nfc_hci_dev *hdev,
 				u32 im_protocols, u32 tm_protocols)
 {
 	int r;

 	u8 param[2];
 	u8 mode;

 	param[0] = 0x00;
 	param[1] = 0x00;

 	if (im_protocols & NFC_PROTO_ISO14443_MASK)
 		param[0] |= (1 << 2);

 	if (im_protocols & NFC_PROTO_ISO14443_B_MASK)
 		param[0] |= 1;

 	if (im_protocols & NFC_PROTO_MIFARE_MASK)
 		param[1] |= 1;

 	if (im_protocols & NFC_PROTO_JEWEL_MASK)
 		param[0] |= (1 << 1);

 	if (im_protocols & NFC_PROTO_FELICA_MASK)
 		param[0] |= (1 << 5);

 	if (im_protocols & NFC_PROTO_NFC_DEP_MASK)
 		param[1] |= (1 << 1);

 	if ((im_protocols | tm_protocols) & NFC_PROTO_NFC_DEP_MASK) {
 		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;
 		}
 	}

 	r = nfc_hci_send_event(hdev, MICROREAD_GATE_ID_MREAD_ISO_A,
 			       MICROREAD_EVT_MREAD_DISCOVERY_STOP, NULL, 0);
 	if (r)
 		return r;

 	mode = 0xff;
 	r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
 			      MICROREAD_PAR_P2P_TARGET_MODE, &mode, 1);
 	if (r)
 		return r;

 	if (im_protocols & NFC_PROTO_NFC_DEP_MASK) {
 		r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_INITIATOR,
 				      MICROREAD_PAR_P2P_INITIATOR_GI,
 				      hdev->gb, hdev->gb_len);
 		if (r)
 			return r;
 	}

 	if (tm_protocols & NFC_PROTO_NFC_DEP_MASK) {
 		r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
 				      MICROREAD_PAR_P2P_TARGET_GT,
 				      hdev->gb, hdev->gb_len);
 		if (r)
 			return r;

 		mode = 0x02;
 		r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
 				      MICROREAD_PAR_P2P_TARGET_MODE, &mode, 1);
 		if (r)
 			return r;
 	}

 	return nfc_hci_send_event(hdev, MICROREAD_GATE_ID_MREAD_ISO_A,
 				  MICROREAD_EVT_MREAD_DISCOVERY_START_SOME,
 				  param, 2);
 }

 static int microread_dep_link_up(struct nfc_hci_dev *hdev,
 				struct nfc_target *target, u8 comm_mode,
 				u8 *gb, size_t gb_len)
 {
 	struct sk_buff *rgb_skb = NULL;
 	int r;

 	r = nfc_hci_get_param(hdev, target->hci_reader_gate,
 			      MICROREAD_PAR_P2P_INITIATOR_GT, &rgb_skb);
 	if (r < 0)
 		return r;

 	if (rgb_skb->len == 0 || rgb_skb->len > NFC_GB_MAXSIZE) {
 		r = -EPROTO;
 		goto exit;
 	}

 	r = nfc_set_remote_general_bytes(hdev->ndev, rgb_skb->data,
 					 rgb_skb->len);
 	if (r == 0)
 		r = nfc_dep_link_is_up(hdev->ndev, target->idx, comm_mode,
 				       NFC_RF_INITIATOR);
 exit:
 	kfree_skb(rgb_skb);

 	return r;
 }

 static int microread_dep_link_down(struct nfc_hci_dev *hdev)
 {
 	return nfc_hci_send_event(hdev, MICROREAD_GATE_ID_P2P_INITIATOR,
 				  MICROREAD_EVT_MREAD_DISCOVERY_STOP, NULL, 0);
 }

 static int microread_target_from_gate(struct nfc_hci_dev *hdev, u8 gate,
 				      struct nfc_target *target)
 {
 	switch (gate) {
 	case MICROREAD_GATE_ID_P2P_INITIATOR:
 		target->supported_protocols = NFC_PROTO_NFC_DEP_MASK;
 		break;
 	default:
 		return -EPROTO;
 	}

 	return 0;
 }

 static int microread_complete_target_discovered(struct nfc_hci_dev *hdev,
 						u8 gate,
 						struct nfc_target *target)
 {
 	return 0;
 }

 #define MICROREAD_CB_TYPE_READER_ALL 1

 static void microread_im_transceive_cb(void *context, struct sk_buff *skb,
 				       int err)
 {
 	struct microread_info *info = context;

 	switch (info->async_cb_type) {
 	case MICROREAD_CB_TYPE_READER_ALL:
 		if (err == 0) {
 			if (skb->len == 0) {
 				err = -EPROTO;
 				kfree_skb(skb);
 				info->async_cb(info->async_cb_context, NULL,
 					       -EPROTO);
 				return;
 			}

 			if (skb->data[skb->len - 1] != 0) {
 				err = nfc_hci_result_to_errno(
 						       skb->data[skb->len - 1]);
 				kfree_skb(skb);
 				info->async_cb(info->async_cb_context, NULL,
 					       err);
 				return;
 			}

 			skb_trim(skb, skb->len - 1);	/* RF Error ind. */
 		}
 		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 microread_im_transceive(struct nfc_hci_dev *hdev,
 				   struct nfc_target *target,
 				   struct sk_buff *skb, data_exchange_cb_t cb,
 				   void *cb_context)
 {
 	struct microread_info *info = nfc_hci_get_clientdata(hdev);
 	u8 control_bits;
 	u16 crc;

 	pr_info("data exchange to gate 0x%x\n", target->hci_reader_gate);

 	if (target->hci_reader_gate == MICROREAD_GATE_ID_P2P_INITIATOR) {
 		*skb_push(skb, 1) = 0;

 		return nfc_hci_send_event(hdev, target->hci_reader_gate,
 				     MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_TO_RF,
 				     skb->data, skb->len);
 	}

 	switch (target->hci_reader_gate) {
 	case MICROREAD_GATE_ID_MREAD_ISO_A:
 		control_bits = 0xCB;
 		break;
 	case MICROREAD_GATE_ID_MREAD_ISO_A_3:
 		control_bits = 0xCB;
 		break;
 	case MICROREAD_GATE_ID_MREAD_ISO_B:
 		control_bits = 0xCB;
 		break;
 	case MICROREAD_GATE_ID_MREAD_NFC_T1:
 		control_bits = 0x1B;

 		crc = crc_ccitt(0xffff, skb->data, skb->len);
 		crc = ~crc;
 		*skb_put(skb, 1) = crc & 0xff;
 		*skb_put(skb, 1) = crc >> 8;
 		break;
 	case MICROREAD_GATE_ID_MREAD_NFC_T3:
 		control_bits = 0xDB;
 		break;
 	default:
 		pr_info("Abort im_transceive to invalid gate 0x%x\n",
 			target->hci_reader_gate);
 		return 1;
 	}

 	*skb_push(skb, 1) = control_bits;

 	info->async_cb_type = MICROREAD_CB_TYPE_READER_ALL;
 	info->async_cb = cb;
 	info->async_cb_context = cb_context;

 	return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
 				      MICROREAD_CMD_MREAD_EXCHANGE,
 				      skb->data, skb->len,
 				      microread_im_transceive_cb, info);
 }

 static int microread_tm_send(struct nfc_hci_dev *hdev, struct sk_buff *skb)
 {
 	int r;

 	r = nfc_hci_send_event(hdev, MICROREAD_GATE_ID_P2P_TARGET,
 			       MICROREAD_EVT_MCARD_EXCHANGE,
 			       skb->data, skb->len);

 	kfree_skb(skb);

 	return r;
 }

 static void microread_target_discovered(struct nfc_hci_dev *hdev, u8 gate,
 					struct sk_buff *skb)
 {
 	struct nfc_target *targets;
 	int r = 0;

 	pr_info("target discovered to gate 0x%x\n", gate);

 	targets = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
 	if (targets == NULL) {
 		r = -ENOMEM;
 		goto exit;
 	}

 	targets->hci_reader_gate = gate;

 	switch (gate) {
 	case MICROREAD_GATE_ID_MREAD_ISO_A:
 		targets->supported_protocols =
 		      nfc_hci_sak_to_protocol(skb->data[MICROREAD_EMCF_A_SAK]);
 		targets->sens_res =
 			 be16_to_cpu(*(u16 *)&skb->data[MICROREAD_EMCF_A_ATQA]);
 		targets->sel_res = skb->data[MICROREAD_EMCF_A_SAK];
 		targets->nfcid1_len = skb->data[MICROREAD_EMCF_A_LEN];
 		if (targets->nfcid1_len > sizeof(targets->nfcid1)) {
 			r = -EINVAL;
 			goto exit_free;
 		}
 		memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_A_UID],
 		       targets->nfcid1_len);
 		break;
 	case MICROREAD_GATE_ID_MREAD_ISO_A_3:
 		targets->supported_protocols =
 		      nfc_hci_sak_to_protocol(skb->data[MICROREAD_EMCF_A3_SAK]);
 		targets->sens_res =
 			 be16_to_cpu(*(u16 *)&skb->data[MICROREAD_EMCF_A3_ATQA]);
 		targets->sel_res = skb->data[MICROREAD_EMCF_A3_SAK];
 		targets->nfcid1_len = skb->data[MICROREAD_EMCF_A3_LEN];
 		if (targets->nfcid1_len > sizeof(targets->nfcid1)) {
 			r = -EINVAL;
 			goto exit_free;
 		}
 		memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_A3_UID],
 		       targets->nfcid1_len);
 		break;
 	case MICROREAD_GATE_ID_MREAD_ISO_B:
 		targets->supported_protocols = NFC_PROTO_ISO14443_B_MASK;
 		memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_B_UID], 4);
 		targets->nfcid1_len = 4;
 		break;
 	case MICROREAD_GATE_ID_MREAD_NFC_T1:
 		targets->supported_protocols = NFC_PROTO_JEWEL_MASK;
 		targets->sens_res =
 			le16_to_cpu(*(u16 *)&skb->data[MICROREAD_EMCF_T1_ATQA]);
 		memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_T1_UID], 4);
 		targets->nfcid1_len = 4;
 		break;
 	case MICROREAD_GATE_ID_MREAD_NFC_T3:
 		targets->supported_protocols = NFC_PROTO_FELICA_MASK;
 		memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_T3_UID], 8);
 		targets->nfcid1_len = 8;
 		break;
 	default:
 		pr_info("discard target discovered to gate 0x%x\n", gate);
 		goto exit_free;
 	}

 	r = nfc_targets_found(hdev->ndev, targets, 1);

 exit_free:
 	kfree(targets);

 exit:
 	kfree_skb(skb);

 	if (r)
 		pr_err("Failed to handle discovered target err=%d\n", r);
 }

 static int microread_event_received(struct nfc_hci_dev *hdev, u8 pipe,
 				     u8 event, struct sk_buff *skb)
 {
 	int r;
 	u8 gate = hdev->pipes[pipe].gate;
 	u8 mode;

 	pr_info("Microread received event 0x%x to gate 0x%x\n", event, gate);

 	switch (event) {
 	case MICROREAD_EVT_MREAD_CARD_FOUND:
 		microread_target_discovered(hdev, gate, skb);
 		return 0;

 	case MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_FROM_RF:
 		if (skb->len < 1) {
 			kfree_skb(skb);
 			return -EPROTO;
 		}

 		if (skb->data[skb->len - 1]) {
 			kfree_skb(skb);
 			return -EIO;
 		}

 		skb_trim(skb, skb->len - 1);

 		r = nfc_tm_data_received(hdev->ndev, skb);
 		break;

 	case MICROREAD_EVT_MCARD_FIELD_ON:
 	case MICROREAD_EVT_MCARD_FIELD_OFF:
 		kfree_skb(skb);
 		return 0;

 	case MICROREAD_EVT_P2P_TARGET_ACTIVATED:
 		r = nfc_tm_activated(hdev->ndev, NFC_PROTO_NFC_DEP_MASK,
 				     NFC_COMM_PASSIVE, skb->data,
 				     skb->len);

 		kfree_skb(skb);
 		break;

 	case MICROREAD_EVT_MCARD_EXCHANGE:
 		if (skb->len < 1) {
 			kfree_skb(skb);
 			return -EPROTO;
 		}

 		if (skb->data[skb->len-1]) {
 			kfree_skb(skb);
 			return -EIO;
 		}

 		skb_trim(skb, skb->len - 1);

 		r = nfc_tm_data_received(hdev->ndev, skb);
 		break;

 	case MICROREAD_EVT_P2P_TARGET_DEACTIVATED:
 		kfree_skb(skb);

 		mode = 0xff;
 		r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
 				      MICROREAD_PAR_P2P_TARGET_MODE, &mode, 1);
 		if (r)
 			break;

 		r = nfc_hci_send_event(hdev, gate,
 				       MICROREAD_EVT_MREAD_DISCOVERY_STOP, NULL,
 				       0);
 		break;

 	default:
 		return 1;
 	}

 	return r;
 }

 static struct nfc_hci_ops microread_hci_ops = {
 	.open = microread_open,
 	.close = microread_close,
 	.hci_ready = microread_hci_ready,
 	.xmit = microread_xmit,
 	.start_poll = microread_start_poll,
 	.dep_link_up = microread_dep_link_up,
 	.dep_link_down = microread_dep_link_down,
 	.target_from_gate = microread_target_from_gate,
 	.complete_target_discovered = microread_complete_target_discovered,
 	.im_transceive = microread_im_transceive,
 	.tm_send = microread_tm_send,
 	.check_presence = NULL,
 	.event_received = microread_event_received,
 };

 int microread_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 microread_info *info;
 	unsigned long quirks = 0;
 	u32 protocols;
 	struct nfc_hci_init_data init_data;
 	int r;

 	info = kzalloc(sizeof(struct microread_info), GFP_KERNEL);
 	if (!info) {
 		r = -ENOMEM;
 		goto err_info_alloc;
 	}

 	info->phy_ops = phy_ops;
 	info->phy_id = phy_id;

 	init_data.gate_count = ARRAY_SIZE(microread_gates);
 	memcpy(init_data.gates, microread_gates, sizeof(microread_gates));

 	strcpy(init_data.session_id, "MICROREA");

 	set_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &quirks);

 	protocols = NFC_PROTO_JEWEL_MASK |
 		    NFC_PROTO_MIFARE_MASK |
 		    NFC_PROTO_FELICA_MASK |
 		    NFC_PROTO_ISO14443_MASK |
 		    NFC_PROTO_ISO14443_B_MASK |
 		    NFC_PROTO_NFC_DEP_MASK;

 	info->hdev = nfc_hci_allocate_device(&microread_hci_ops, &init_data,
 					     quirks, protocols, llc_name,
 					     phy_headroom +
 					     MICROREAD_CMDS_HEADROOM,
 					     phy_tailroom +
 					     MICROREAD_CMD_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);

 err_info_alloc:
 	return r;
 }
 EXPORT_SYMBOL(microread_probe);

 void microread_remove(struct nfc_hci_dev *hdev)
 {
 	struct microread_info *info = nfc_hci_get_clientdata(hdev);

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

 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION(DRIVER_DESC);
	/*
	* HCI based Driver for Inside Secure microread NFC Chip
	*
	* Copyright (C) 2013 Intel Corporation. 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/>.
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/module.h>
	#include <linux/delay.h>
	#include <linux/slab.h>
	#include <linux/crc-ccitt.h>

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

	#include "microread.h"

	/* Proprietary gates, events, commands and registers */
	/* Admin */
	#define MICROREAD_GATE_ID_ADM NFC_HCI_ADMIN_GATE
	#define MICROREAD_GATE_ID_MGT 0x01
	#define MICROREAD_GATE_ID_OS 0x02
	#define MICROREAD_GATE_ID_TESTRF 0x03
	#define MICROREAD_GATE_ID_LOOPBACK NFC_HCI_LOOPBACK_GATE
	#define MICROREAD_GATE_ID_IDT NFC_HCI_ID_MGMT_GATE
	#define MICROREAD_GATE_ID_LMS NFC_HCI_LINK_MGMT_GATE

	/* Reader */
	#define MICROREAD_GATE_ID_MREAD_GEN 0x10
	#define MICROREAD_GATE_ID_MREAD_ISO_B NFC_HCI_RF_READER_B_GATE
	#define MICROREAD_GATE_ID_MREAD_NFC_T1 0x12
	#define MICROREAD_GATE_ID_MREAD_ISO_A NFC_HCI_RF_READER_A_GATE
	#define MICROREAD_GATE_ID_MREAD_NFC_T3 0x14
	#define MICROREAD_GATE_ID_MREAD_ISO_15_3 0x15
	#define MICROREAD_GATE_ID_MREAD_ISO_15_2 0x16
	#define MICROREAD_GATE_ID_MREAD_ISO_B_3 0x17
	#define MICROREAD_GATE_ID_MREAD_BPRIME 0x18
	#define MICROREAD_GATE_ID_MREAD_ISO_A_3 0x19

	/* Card */
	#define MICROREAD_GATE_ID_MCARD_GEN 0x20
	#define MICROREAD_GATE_ID_MCARD_ISO_B 0x21
	#define MICROREAD_GATE_ID_MCARD_BPRIME 0x22
	#define MICROREAD_GATE_ID_MCARD_ISO_A 0x23
	#define MICROREAD_GATE_ID_MCARD_NFC_T3 0x24
	#define MICROREAD_GATE_ID_MCARD_ISO_15_3 0x25
	#define MICROREAD_GATE_ID_MCARD_ISO_15_2 0x26
	#define MICROREAD_GATE_ID_MCARD_ISO_B_2 0x27
	#define MICROREAD_GATE_ID_MCARD_ISO_CUSTOM 0x28
	#define MICROREAD_GATE_ID_SECURE_ELEMENT 0x2F

	/* P2P */
	#define MICROREAD_GATE_ID_P2P_GEN 0x30
	#define MICROREAD_GATE_ID_P2P_TARGET 0x31
	#define MICROREAD_PAR_P2P_TARGET_MODE 0x01
	#define MICROREAD_PAR_P2P_TARGET_GT 0x04
	#define MICROREAD_GATE_ID_P2P_INITIATOR 0x32
	#define MICROREAD_PAR_P2P_INITIATOR_GI 0x01
	#define MICROREAD_PAR_P2P_INITIATOR_GT 0x03

	/* Those pipes are created/opened by default in the chip */
	#define MICROREAD_PIPE_ID_LMS 0x00
	#define MICROREAD_PIPE_ID_ADMIN 0x01
	#define MICROREAD_PIPE_ID_MGT 0x02
	#define MICROREAD_PIPE_ID_OS 0x03
	#define MICROREAD_PIPE_ID_HDS_LOOPBACK 0x04
	#define MICROREAD_PIPE_ID_HDS_IDT 0x05
	#define MICROREAD_PIPE_ID_HDS_MCARD_ISO_B 0x08
	#define MICROREAD_PIPE_ID_HDS_MCARD_ISO_BPRIME 0x09
	#define MICROREAD_PIPE_ID_HDS_MCARD_ISO_A 0x0A
	#define MICROREAD_PIPE_ID_HDS_MCARD_ISO_15_3 0x0B
	#define MICROREAD_PIPE_ID_HDS_MCARD_ISO_15_2 0x0C
	#define MICROREAD_PIPE_ID_HDS_MCARD_NFC_T3 0x0D
	#define MICROREAD_PIPE_ID_HDS_MCARD_ISO_B_2 0x0E
	#define MICROREAD_PIPE_ID_HDS_MCARD_CUSTOM 0x0F
	#define MICROREAD_PIPE_ID_HDS_MREAD_ISO_B 0x10
	#define MICROREAD_PIPE_ID_HDS_MREAD_NFC_T1 0x11
	#define MICROREAD_PIPE_ID_HDS_MREAD_ISO_A 0x12
	#define MICROREAD_PIPE_ID_HDS_MREAD_ISO_15_3 0x13
	#define MICROREAD_PIPE_ID_HDS_MREAD_ISO_15_2 0x14
	#define MICROREAD_PIPE_ID_HDS_MREAD_NFC_T3 0x15
	#define MICROREAD_PIPE_ID_HDS_MREAD_ISO_B_3 0x16
	#define MICROREAD_PIPE_ID_HDS_MREAD_BPRIME 0x17
	#define MICROREAD_PIPE_ID_HDS_MREAD_ISO_A_3 0x18
	#define MICROREAD_PIPE_ID_HDS_MREAD_GEN 0x1B
	#define MICROREAD_PIPE_ID_HDS_STACKED_ELEMENT 0x1C
	#define MICROREAD_PIPE_ID_HDS_INSTANCES 0x1D
	#define MICROREAD_PIPE_ID_HDS_TESTRF 0x1E
	#define MICROREAD_PIPE_ID_HDS_P2P_TARGET 0x1F
	#define MICROREAD_PIPE_ID_HDS_P2P_INITIATOR 0x20

	/* Events */
	#define MICROREAD_EVT_MREAD_DISCOVERY_OCCURED NFC_HCI_EVT_TARGET_DISCOVERED
	#define MICROREAD_EVT_MREAD_CARD_FOUND 0x3D
	#define MICROREAD_EMCF_A_ATQA 0
	#define MICROREAD_EMCF_A_SAK 2
	#define MICROREAD_EMCF_A_LEN 3
	#define MICROREAD_EMCF_A_UID 4
	#define MICROREAD_EMCF_A3_ATQA 0
	#define MICROREAD_EMCF_A3_SAK 2
	#define MICROREAD_EMCF_A3_LEN 3
	#define MICROREAD_EMCF_A3_UID 4
	#define MICROREAD_EMCF_B_UID 0
	#define MICROREAD_EMCF_T1_ATQA 0
	#define MICROREAD_EMCF_T1_UID 4
	#define MICROREAD_EMCF_T3_UID 0
	#define MICROREAD_EVT_MREAD_DISCOVERY_START NFC_HCI_EVT_READER_REQUESTED
	#define MICROREAD_EVT_MREAD_DISCOVERY_START_SOME 0x3E
	#define MICROREAD_EVT_MREAD_DISCOVERY_STOP NFC_HCI_EVT_END_OPERATION
	#define MICROREAD_EVT_MREAD_SIM_REQUESTS 0x3F
	#define MICROREAD_EVT_MCARD_EXCHANGE NFC_HCI_EVT_TARGET_DISCOVERED
	#define MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_TO_RF 0x20
	#define MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_FROM_RF 0x21
	#define MICROREAD_EVT_MCARD_FIELD_ON 0x11
	#define MICROREAD_EVT_P2P_TARGET_ACTIVATED 0x13
	#define MICROREAD_EVT_P2P_TARGET_DEACTIVATED 0x12
	#define MICROREAD_EVT_MCARD_FIELD_OFF 0x14

	/* Commands */
	#define MICROREAD_CMD_MREAD_EXCHANGE 0x10
	#define MICROREAD_CMD_MREAD_SUBSCRIBE 0x3F

	/* Hosts IDs */
	#define MICROREAD_ELT_ID_HDS NFC_HCI_TERMINAL_HOST_ID
	#define MICROREAD_ELT_ID_SIM NFC_HCI_UICC_HOST_ID
	#define MICROREAD_ELT_ID_SE1 0x03
	#define MICROREAD_ELT_ID_SE2 0x04
	#define MICROREAD_ELT_ID_SE3 0x05

	static struct nfc_hci_gate microread_gates[] = {
	{MICROREAD_GATE_ID_ADM, MICROREAD_PIPE_ID_ADMIN},
	{MICROREAD_GATE_ID_LOOPBACK, MICROREAD_PIPE_ID_HDS_LOOPBACK},
	{MICROREAD_GATE_ID_IDT, MICROREAD_PIPE_ID_HDS_IDT},
	{MICROREAD_GATE_ID_LMS, MICROREAD_PIPE_ID_LMS},
	{MICROREAD_GATE_ID_MREAD_ISO_B, MICROREAD_PIPE_ID_HDS_MREAD_ISO_B},
	{MICROREAD_GATE_ID_MREAD_ISO_A, MICROREAD_PIPE_ID_HDS_MREAD_ISO_A},
	{MICROREAD_GATE_ID_MREAD_ISO_A_3, MICROREAD_PIPE_ID_HDS_MREAD_ISO_A_3},
	{MICROREAD_GATE_ID_MGT, MICROREAD_PIPE_ID_MGT},
	{MICROREAD_GATE_ID_OS, MICROREAD_PIPE_ID_OS},
	{MICROREAD_GATE_ID_MREAD_NFC_T1, MICROREAD_PIPE_ID_HDS_MREAD_NFC_T1},
	{MICROREAD_GATE_ID_MREAD_NFC_T3, MICROREAD_PIPE_ID_HDS_MREAD_NFC_T3},
	{MICROREAD_GATE_ID_P2P_TARGET, MICROREAD_PIPE_ID_HDS_P2P_TARGET},
	{MICROREAD_GATE_ID_P2P_INITIATOR, MICROREAD_PIPE_ID_HDS_P2P_INITIATOR}
	};

	/* Largest headroom needed for outgoing custom commands */
	#define MICROREAD_CMDS_HEADROOM 2
	#define MICROREAD_CMD_TAILROOM 2

	struct microread_info {
	struct nfc_phy_ops *phy_ops;
	void *phy_id;

	struct nfc_hci_dev *hdev;

	int async_cb_type;
	data_exchange_cb_t async_cb;
	void *async_cb_context;
	};

	static int microread_open(struct nfc_hci_dev *hdev)
	{
	struct microread_info *info = nfc_hci_get_clientdata(hdev);

	return info->phy_ops->enable(info->phy_id);
	}

	static void microread_close(struct nfc_hci_dev *hdev)
	{
	struct microread_info *info = nfc_hci_get_clientdata(hdev);

	info->phy_ops->disable(info->phy_id);
	}

	static int microread_hci_ready(struct nfc_hci_dev *hdev)
	{
	int r;
	u8 param[4];

	param[0] = 0x03;
	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_ISO_A,
	MICROREAD_CMD_MREAD_SUBSCRIBE, param, 1, NULL);
	if (r)
	return r;

	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_ISO_A_3,
	MICROREAD_CMD_MREAD_SUBSCRIBE, NULL, 0, NULL);
	if (r)
	return r;

	param[0] = 0x00;
	param[1] = 0x03;
	param[2] = 0x00;
	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_ISO_B,
	MICROREAD_CMD_MREAD_SUBSCRIBE, param, 3, NULL);
	if (r)
	return r;

	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_NFC_T1,
	MICROREAD_CMD_MREAD_SUBSCRIBE, NULL, 0, NULL);
	if (r)
	return r;

	param[0] = 0xFF;
	param[1] = 0xFF;
	param[2] = 0x00;
	param[3] = 0x00;
	r = nfc_hci_send_cmd(hdev, MICROREAD_GATE_ID_MREAD_NFC_T3,
	MICROREAD_CMD_MREAD_SUBSCRIBE, param, 4, NULL);

	return r;
	}

	static int microread_xmit(struct nfc_hci_dev hdev, struct sk_buff skb)
	{
	struct microread_info *info = nfc_hci_get_clientdata(hdev);

	return info->phy_ops->write(info->phy_id, skb);
	}

	static int microread_start_poll(struct nfc_hci_dev *hdev,
	u32 im_protocols, u32 tm_protocols)
	{
	int r;

	u8 param[2];
	u8 mode;

	param[0] = 0x00;
	param[1] = 0x00;

	if (im_protocols & NFC_PROTO_ISO14443_MASK)
	param[0] \|= (1 << 2);

	if (im_protocols & NFC_PROTO_ISO14443_B_MASK)
	param[0] \|= 1;

	if (im_protocols & NFC_PROTO_MIFARE_MASK)
	param[1] \|= 1;

	if (im_protocols & NFC_PROTO_JEWEL_MASK)
	param[0] \|= (1 << 1);

	if (im_protocols & NFC_PROTO_FELICA_MASK)
	param[0] \|= (1 << 5);

	if (im_protocols & NFC_PROTO_NFC_DEP_MASK)
	param[1] \|= (1 << 1);

	if ((im_protocols \| tm_protocols) & NFC_PROTO_NFC_DEP_MASK) {
	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;
	}
	}

	r = nfc_hci_send_event(hdev, MICROREAD_GATE_ID_MREAD_ISO_A,
	MICROREAD_EVT_MREAD_DISCOVERY_STOP, NULL, 0);
	if (r)
	return r;

	mode = 0xff;
	r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
	MICROREAD_PAR_P2P_TARGET_MODE, &mode, 1);
	if (r)
	return r;

	if (im_protocols & NFC_PROTO_NFC_DEP_MASK) {
	r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_INITIATOR,
	MICROREAD_PAR_P2P_INITIATOR_GI,
	hdev->gb, hdev->gb_len);
	if (r)
	return r;
	}

	if (tm_protocols & NFC_PROTO_NFC_DEP_MASK) {
	r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
	MICROREAD_PAR_P2P_TARGET_GT,
	hdev->gb, hdev->gb_len);
	if (r)
	return r;

	mode = 0x02;
	r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
	MICROREAD_PAR_P2P_TARGET_MODE, &mode, 1);
	if (r)
	return r;
	}

	return nfc_hci_send_event(hdev, MICROREAD_GATE_ID_MREAD_ISO_A,
	MICROREAD_EVT_MREAD_DISCOVERY_START_SOME,
	param, 2);
	}

	static int microread_dep_link_up(struct nfc_hci_dev *hdev,
	struct nfc_target *target, u8 comm_mode,
	u8 *gb, size_t gb_len)
	{
	struct sk_buff *rgb_skb = NULL;
	int r;

	r = nfc_hci_get_param(hdev, target->hci_reader_gate,
	MICROREAD_PAR_P2P_INITIATOR_GT, &rgb_skb);
	if (r < 0)
	return r;

	if (rgb_skb->len == 0 \|\| rgb_skb->len > NFC_GB_MAXSIZE) {
	r = -EPROTO;
	goto exit;
	}

	r = nfc_set_remote_general_bytes(hdev->ndev, rgb_skb->data,
	rgb_skb->len);
	if (r == 0)
	r = nfc_dep_link_is_up(hdev->ndev, target->idx, comm_mode,
	NFC_RF_INITIATOR);
	exit:
	kfree_skb(rgb_skb);

	return r;
	}

	static int microread_dep_link_down(struct nfc_hci_dev *hdev)
	{
	return nfc_hci_send_event(hdev, MICROREAD_GATE_ID_P2P_INITIATOR,
	MICROREAD_EVT_MREAD_DISCOVERY_STOP, NULL, 0);
	}

	static int microread_target_from_gate(struct nfc_hci_dev *hdev, u8 gate,
	struct nfc_target *target)
	{
	switch (gate) {
	case MICROREAD_GATE_ID_P2P_INITIATOR:
	target->supported_protocols = NFC_PROTO_NFC_DEP_MASK;
	break;
	default:
	return -EPROTO;
	}

	return 0;
	}

	static int microread_complete_target_discovered(struct nfc_hci_dev *hdev,
	u8 gate,
	struct nfc_target *target)
	{
	return 0;
	}

	#define MICROREAD_CB_TYPE_READER_ALL 1

	static void microread_im_transceive_cb(void context, struct sk_buff skb,
	int err)
	{
	struct microread_info *info = context;

	switch (info->async_cb_type) {
	case MICROREAD_CB_TYPE_READER_ALL:
	if (err == 0) {
	if (skb->len == 0) {
	err = -EPROTO;
	kfree_skb(skb);
	info->async_cb(info->async_cb_context, NULL,
	-EPROTO);
	return;
	}

	if (skb->data[skb->len - 1] != 0) {
	err = nfc_hci_result_to_errno(
	skb->data[skb->len - 1]);
	kfree_skb(skb);
	info->async_cb(info->async_cb_context, NULL,
	err);
	return;
	}

	skb_trim(skb, skb->len - 1); /* RF Error ind. */
	}
	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 microread_im_transceive(struct nfc_hci_dev *hdev,
	struct nfc_target *target,
	struct sk_buff *skb, data_exchange_cb_t cb,
	void *cb_context)
	{
	struct microread_info *info = nfc_hci_get_clientdata(hdev);
	u8 control_bits;
	u16 crc;

	pr_info("data exchange to gate 0x%x\n", target->hci_reader_gate);

	if (target->hci_reader_gate == MICROREAD_GATE_ID_P2P_INITIATOR) {
	*skb_push(skb, 1) = 0;

	return nfc_hci_send_event(hdev, target->hci_reader_gate,
	MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_TO_RF,
	skb->data, skb->len);
	}

	switch (target->hci_reader_gate) {
	case MICROREAD_GATE_ID_MREAD_ISO_A:
	control_bits = 0xCB;
	break;
	case MICROREAD_GATE_ID_MREAD_ISO_A_3:
	control_bits = 0xCB;
	break;
	case MICROREAD_GATE_ID_MREAD_ISO_B:
	control_bits = 0xCB;
	break;
	case MICROREAD_GATE_ID_MREAD_NFC_T1:
	control_bits = 0x1B;

	crc = crc_ccitt(0xffff, skb->data, skb->len);
	crc = ~crc;
	*skb_put(skb, 1) = crc & 0xff;
	*skb_put(skb, 1) = crc >> 8;
	break;
	case MICROREAD_GATE_ID_MREAD_NFC_T3:
	control_bits = 0xDB;
	break;
	default:
	pr_info("Abort im_transceive to invalid gate 0x%x\n",
	target->hci_reader_gate);
	return 1;
	}

	*skb_push(skb, 1) = control_bits;

	info->async_cb_type = MICROREAD_CB_TYPE_READER_ALL;
	info->async_cb = cb;
	info->async_cb_context = cb_context;

	return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
	MICROREAD_CMD_MREAD_EXCHANGE,
	skb->data, skb->len,
	microread_im_transceive_cb, info);
	}

	static int microread_tm_send(struct nfc_hci_dev hdev, struct sk_buff skb)
	{
	int r;

	r = nfc_hci_send_event(hdev, MICROREAD_GATE_ID_P2P_TARGET,
	MICROREAD_EVT_MCARD_EXCHANGE,
	skb->data, skb->len);

	kfree_skb(skb);

	return r;
	}

	static void microread_target_discovered(struct nfc_hci_dev *hdev, u8 gate,
	struct sk_buff *skb)
	{
	struct nfc_target *targets;
	int r = 0;

	pr_info("target discovered to gate 0x%x\n", gate);

	targets = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
	if (targets == NULL) {
	r = -ENOMEM;
	goto exit;
	}

	targets->hci_reader_gate = gate;

	switch (gate) {
	case MICROREAD_GATE_ID_MREAD_ISO_A:
	targets->supported_protocols =
	nfc_hci_sak_to_protocol(skb->data[MICROREAD_EMCF_A_SAK]);
	targets->sens_res =
	be16_to_cpu((u16 )&skb->data[MICROREAD_EMCF_A_ATQA]);
	targets->sel_res = skb->data[MICROREAD_EMCF_A_SAK];
	targets->nfcid1_len = skb->data[MICROREAD_EMCF_A_LEN];
	if (targets->nfcid1_len > sizeof(targets->nfcid1)) {
	r = -EINVAL;
	goto exit_free;
	}
	memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_A_UID],
	targets->nfcid1_len);
	break;
	case MICROREAD_GATE_ID_MREAD_ISO_A_3:
	targets->supported_protocols =
	nfc_hci_sak_to_protocol(skb->data[MICROREAD_EMCF_A3_SAK]);
	targets->sens_res =
	be16_to_cpu((u16 )&skb->data[MICROREAD_EMCF_A3_ATQA]);
	targets->sel_res = skb->data[MICROREAD_EMCF_A3_SAK];
	targets->nfcid1_len = skb->data[MICROREAD_EMCF_A3_LEN];
	if (targets->nfcid1_len > sizeof(targets->nfcid1)) {
	r = -EINVAL;
	goto exit_free;
	}
	memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_A3_UID],
	targets->nfcid1_len);
	break;
	case MICROREAD_GATE_ID_MREAD_ISO_B:
	targets->supported_protocols = NFC_PROTO_ISO14443_B_MASK;
	memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_B_UID], 4);
	targets->nfcid1_len = 4;
	break;
	case MICROREAD_GATE_ID_MREAD_NFC_T1:
	targets->supported_protocols = NFC_PROTO_JEWEL_MASK;
	targets->sens_res =
	le16_to_cpu((u16 )&skb->data[MICROREAD_EMCF_T1_ATQA]);
	memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_T1_UID], 4);
	targets->nfcid1_len = 4;
	break;
	case MICROREAD_GATE_ID_MREAD_NFC_T3:
	targets->supported_protocols = NFC_PROTO_FELICA_MASK;
	memcpy(targets->nfcid1, &skb->data[MICROREAD_EMCF_T3_UID], 8);
	targets->nfcid1_len = 8;
	break;
	default:
	pr_info("discard target discovered to gate 0x%x\n", gate);
	goto exit_free;
	}

	r = nfc_targets_found(hdev->ndev, targets, 1);

	exit_free:
	kfree(targets);

	exit:
	kfree_skb(skb);

	if (r)
	pr_err("Failed to handle discovered target err=%d\n", r);
	}

	static int microread_event_received(struct nfc_hci_dev *hdev, u8 pipe,
	u8 event, struct sk_buff *skb)
	{
	int r;
	u8 gate = hdev->pipes[pipe].gate;
	u8 mode;

	pr_info("Microread received event 0x%x to gate 0x%x\n", event, gate);

	switch (event) {
	case MICROREAD_EVT_MREAD_CARD_FOUND:
	microread_target_discovered(hdev, gate, skb);
	return 0;

	case MICROREAD_EVT_P2P_INITIATOR_EXCHANGE_FROM_RF:
	if (skb->len < 1) {
	kfree_skb(skb);
	return -EPROTO;
	}

	if (skb->data[skb->len - 1]) {
	kfree_skb(skb);
	return -EIO;
	}

	skb_trim(skb, skb->len - 1);

	r = nfc_tm_data_received(hdev->ndev, skb);
	break;

	case MICROREAD_EVT_MCARD_FIELD_ON:
	case MICROREAD_EVT_MCARD_FIELD_OFF:
	kfree_skb(skb);
	return 0;

	case MICROREAD_EVT_P2P_TARGET_ACTIVATED:
	r = nfc_tm_activated(hdev->ndev, NFC_PROTO_NFC_DEP_MASK,
	NFC_COMM_PASSIVE, skb->data,
	skb->len);

	kfree_skb(skb);
	break;

	case MICROREAD_EVT_MCARD_EXCHANGE:
	if (skb->len < 1) {
	kfree_skb(skb);
	return -EPROTO;
	}

	if (skb->data[skb->len-1]) {
	kfree_skb(skb);
	return -EIO;
	}

	skb_trim(skb, skb->len - 1);

	r = nfc_tm_data_received(hdev->ndev, skb);
	break;

	case MICROREAD_EVT_P2P_TARGET_DEACTIVATED:
	kfree_skb(skb);

	mode = 0xff;
	r = nfc_hci_set_param(hdev, MICROREAD_GATE_ID_P2P_TARGET,
	MICROREAD_PAR_P2P_TARGET_MODE, &mode, 1);
	if (r)
	break;

	r = nfc_hci_send_event(hdev, gate,
	MICROREAD_EVT_MREAD_DISCOVERY_STOP, NULL,
	0);
	break;

	default:
	return 1;
	}

	return r;
	}

	static struct nfc_hci_ops microread_hci_ops = {
	.open = microread_open,
	.close = microread_close,
	.hci_ready = microread_hci_ready,
	.xmit = microread_xmit,
	.start_poll = microread_start_poll,
	.dep_link_up = microread_dep_link_up,
	.dep_link_down = microread_dep_link_down,
	.target_from_gate = microread_target_from_gate,
	.complete_target_discovered = microread_complete_target_discovered,
	.im_transceive = microread_im_transceive,
	.tm_send = microread_tm_send,
	.check_presence = NULL,
	.event_received = microread_event_received,
	};

	int microread_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 microread_info *info;
	unsigned long quirks = 0;
	u32 protocols;
	struct nfc_hci_init_data init_data;
	int r;

	info = kzalloc(sizeof(struct microread_info), GFP_KERNEL);
	if (!info) {
	r = -ENOMEM;
	goto err_info_alloc;
	}

	info->phy_ops = phy_ops;
	info->phy_id = phy_id;

	init_data.gate_count = ARRAY_SIZE(microread_gates);
	memcpy(init_data.gates, microread_gates, sizeof(microread_gates));

	strcpy(init_data.session_id, "MICROREA");

	set_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &quirks);

	protocols = NFC_PROTO_JEWEL_MASK \|
	NFC_PROTO_MIFARE_MASK \|
	NFC_PROTO_FELICA_MASK \|
	NFC_PROTO_ISO14443_MASK \|
	NFC_PROTO_ISO14443_B_MASK \|
	NFC_PROTO_NFC_DEP_MASK;

	info->hdev = nfc_hci_allocate_device(&microread_hci_ops, &init_data,
	quirks, protocols, llc_name,
	phy_headroom +
	MICROREAD_CMDS_HEADROOM,
	phy_tailroom +
	MICROREAD_CMD_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);

	err_info_alloc:
	return r;
	}
	EXPORT_SYMBOL(microread_probe);

	void microread_remove(struct nfc_hci_dev *hdev)
	{
	struct microread_info *info = nfc_hci_get_clientdata(hdev);

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

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