/*
   * NFC Digital Protocol stack
   * Copyright (c) 2013, Intel Corporation.
   *
   * 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 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.
   *
   */

  #define pr_fmt(fmt) "digital: %s: " fmt, __func__

  #include <linux/module.h>
  
  #include "digital.h"

  #define DIGITAL_PROTO_NFCA_RF_TECH \

  	(NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK | \
  	NFC_PROTO_NFC_DEP_MASK | NFC_PROTO_ISO14443_MASK)

  #define DIGITAL_PROTO_NFCB_RF_TECH	NFC_PROTO_ISO14443_B_MASK

  #define DIGITAL_PROTO_NFCF_RF_TECH \
  	(NFC_PROTO_FELICA_MASK | NFC_PROTO_NFC_DEP_MASK)

  #define DIGITAL_PROTO_ISO15693_RF_TECH	NFC_PROTO_ISO15693_MASK

  /* Delay between each poll frame (ms) */
  #define DIGITAL_POLL_INTERVAL 10

  struct digital_cmd {
  	struct list_head queue;
  
  	u8 type;
  	u8 pending;
  
  	u16 timeout;
  	struct sk_buff *req;
  	struct sk_buff *resp;

  	struct digital_tg_mdaa_params *mdaa_params;

  
  	nfc_digital_cmd_complete_t cmd_cb;
  	void *cb_context;
  };
  
  struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev,
  				  unsigned int len)
  {
  	struct sk_buff *skb;
  
  	skb = alloc_skb(len + ddev->tx_headroom + ddev->tx_tailroom,
  			GFP_KERNEL);
  	if (skb)
  		skb_reserve(skb, ddev->tx_headroom);
  
  	return skb;
  }

  void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init,
  			 u8 bitwise_inv, u8 msb_first)
  {
  	u16 crc;
  
  	crc = crc_func(init, skb->data, skb->len);
  
  	if (bitwise_inv)
  		crc = ~crc;
  
  	if (msb_first)
  		crc = __fswab16(crc);

  	skb_put_u8(skb, crc & 0xFF);
  	skb_put_u8(skb, (crc >> 8) & 0xFF);

  }
  
  int digital_skb_check_crc(struct sk_buff *skb, crc_func_t crc_func,
  			  u16 crc_init, u8 bitwise_inv, u8 msb_first)
  {
  	int rc;
  	u16 crc;
  
  	if (skb->len <= 2)
  		return -EIO;
  
  	crc = crc_func(crc_init, skb->data, skb->len - 2);
  
  	if (bitwise_inv)
  		crc = ~crc;
  
  	if (msb_first)
  		crc = __swab16(crc);
  
  	rc = (skb->data[skb->len - 2] - (crc & 0xFF)) +
  	     (skb->data[skb->len - 1] - ((crc >> 8) & 0xFF));
  
  	if (rc)
  		return -EIO;
  
  	skb_trim(skb, skb->len - 2);
  
  	return 0;
  }

  static inline void digital_switch_rf(struct nfc_digital_dev *ddev, bool on)
  {
  	ddev->ops->switch_rf(ddev, on);
  }
  
  static inline void digital_abort_cmd(struct nfc_digital_dev *ddev)
  {
  	ddev->ops->abort_cmd(ddev);
  }
  
  static void digital_wq_cmd_complete(struct work_struct *work)
  {
  	struct digital_cmd *cmd;
  	struct nfc_digital_dev *ddev = container_of(work,
  						    struct nfc_digital_dev,
  						    cmd_complete_work);
  
  	mutex_lock(&ddev->cmd_lock);
  
  	cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd,
  				       queue);
  	if (!cmd) {
  		mutex_unlock(&ddev->cmd_lock);
  		return;
  	}
  
  	list_del(&cmd->queue);
  
  	mutex_unlock(&ddev->cmd_lock);
  
  	if (!IS_ERR(cmd->resp))
  		print_hex_dump_debug("DIGITAL RX: ", DUMP_PREFIX_NONE, 16, 1,
  				     cmd->resp->data, cmd->resp->len, false);
  
  	cmd->cmd_cb(ddev, cmd->cb_context, cmd->resp);

  	kfree(cmd->mdaa_params);

  	kfree(cmd);
  
  	schedule_work(&ddev->cmd_work);
  }
  
  static void digital_send_cmd_complete(struct nfc_digital_dev *ddev,
  				      void *arg, struct sk_buff *resp)
  {
  	struct digital_cmd *cmd = arg;
  
  	cmd->resp = resp;
  
  	schedule_work(&ddev->cmd_complete_work);
  }
  
  static void digital_wq_cmd(struct work_struct *work)
  {
  	int rc;
  	struct digital_cmd *cmd;

  	struct digital_tg_mdaa_params *params;

  	struct nfc_digital_dev *ddev = container_of(work,
  						    struct nfc_digital_dev,
  						    cmd_work);
  
  	mutex_lock(&ddev->cmd_lock);
  
  	cmd = list_first_entry_or_null(&ddev->cmd_queue, struct digital_cmd,
  				       queue);
  	if (!cmd || cmd->pending) {
  		mutex_unlock(&ddev->cmd_lock);
  		return;
  	}

  	cmd->pending = 1;

  	mutex_unlock(&ddev->cmd_lock);
  
  	if (cmd->req)
  		print_hex_dump_debug("DIGITAL TX: ", DUMP_PREFIX_NONE, 16, 1,
  				     cmd->req->data, cmd->req->len, false);
  
  	switch (cmd->type) {
  	case DIGITAL_CMD_IN_SEND:
  		rc = ddev->ops->in_send_cmd(ddev, cmd->req, cmd->timeout,
  					    digital_send_cmd_complete, cmd);
  		break;

  
  	case DIGITAL_CMD_TG_SEND:
  		rc = ddev->ops->tg_send_cmd(ddev, cmd->req, cmd->timeout,
  					    digital_send_cmd_complete, cmd);
  		break;
  
  	case DIGITAL_CMD_TG_LISTEN:
  		rc = ddev->ops->tg_listen(ddev, cmd->timeout,
  					  digital_send_cmd_complete, cmd);
  		break;
  
  	case DIGITAL_CMD_TG_LISTEN_MDAA:
  		params = cmd->mdaa_params;
  
  		rc = ddev->ops->tg_listen_mdaa(ddev, params, cmd->timeout,
  					       digital_send_cmd_complete, cmd);
  		break;

  	case DIGITAL_CMD_TG_LISTEN_MD:
  		rc = ddev->ops->tg_listen_md(ddev, cmd->timeout,
  					       digital_send_cmd_complete, cmd);
  		break;

  	default:

  		pr_err("Unknown cmd type %d
  ", cmd->type);

  		return;
  	}
  
  	if (!rc)
  		return;

  	pr_err("in_send_command returned err %d
  ", rc);

  
  	mutex_lock(&ddev->cmd_lock);
  	list_del(&cmd->queue);
  	mutex_unlock(&ddev->cmd_lock);
  
  	kfree_skb(cmd->req);

  	kfree(cmd->mdaa_params);

  	kfree(cmd);
  
  	schedule_work(&ddev->cmd_work);
  }
  
  int digital_send_cmd(struct nfc_digital_dev *ddev, u8 cmd_type,

  		     struct sk_buff *skb, struct digital_tg_mdaa_params *params,
  		     u16 timeout, nfc_digital_cmd_complete_t cmd_cb,
  		     void *cb_context)

  {
  	struct digital_cmd *cmd;

  	cmd = kzalloc(sizeof(*cmd), GFP_KERNEL);

  	if (!cmd)
  		return -ENOMEM;
  
  	cmd->type = cmd_type;
  	cmd->timeout = timeout;
  	cmd->req = skb;

  	cmd->mdaa_params = params;

  	cmd->cmd_cb = cmd_cb;
  	cmd->cb_context = cb_context;
  	INIT_LIST_HEAD(&cmd->queue);
  
  	mutex_lock(&ddev->cmd_lock);
  	list_add_tail(&cmd->queue, &ddev->cmd_queue);
  	mutex_unlock(&ddev->cmd_lock);
  
  	schedule_work(&ddev->cmd_work);
  
  	return 0;
  }
  
  int digital_in_configure_hw(struct nfc_digital_dev *ddev, int type, int param)
  {
  	int rc;
  
  	rc = ddev->ops->in_configure_hw(ddev, type, param);
  	if (rc)

  		pr_err("in_configure_hw failed: %d
  ", rc);

  
  	return rc;
  }

  int digital_tg_configure_hw(struct nfc_digital_dev *ddev, int type, int param)
  {
  	int rc;
  
  	rc = ddev->ops->tg_configure_hw(ddev, type, param);
  	if (rc)

  		pr_err("tg_configure_hw failed: %d
  ", rc);

  
  	return rc;
  }
  
  static int digital_tg_listen_mdaa(struct nfc_digital_dev *ddev, u8 rf_tech)
  {
  	struct digital_tg_mdaa_params *params;

  	params = kzalloc(sizeof(*params), GFP_KERNEL);

  	if (!params)
  		return -ENOMEM;
  
  	params->sens_res = DIGITAL_SENS_RES_NFC_DEP;
  	get_random_bytes(params->nfcid1, sizeof(params->nfcid1));
  	params->sel_res = DIGITAL_SEL_RES_NFC_DEP;
  
  	params->nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
  	params->nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
  	get_random_bytes(params->nfcid2 + 2, NFC_NFCID2_MAXSIZE - 2);
  	params->sc = DIGITAL_SENSF_FELICA_SC;
  
  	return digital_send_cmd(ddev, DIGITAL_CMD_TG_LISTEN_MDAA, NULL, params,
  				500, digital_tg_recv_atr_req, NULL);
  }

  static int digital_tg_listen_md(struct nfc_digital_dev *ddev, u8 rf_tech)
  {
  	return digital_send_cmd(ddev, DIGITAL_CMD_TG_LISTEN_MD, NULL, NULL, 500,
  				digital_tg_recv_md_req, NULL);
  }

  int digital_target_found(struct nfc_digital_dev *ddev,
  			 struct nfc_target *target, u8 protocol)
  {
  	int rc;
  	u8 framing;
  	u8 rf_tech;

  	u8 poll_tech_count;

  	int (*check_crc)(struct sk_buff *skb);
  	void (*add_crc)(struct sk_buff *skb);
  
  	rf_tech = ddev->poll_techs[ddev->poll_tech_index].rf_tech;
  
  	switch (protocol) {
  	case NFC_PROTO_JEWEL:
  		framing = NFC_DIGITAL_FRAMING_NFCA_T1T;
  		check_crc = digital_skb_check_crc_b;
  		add_crc = digital_skb_add_crc_b;
  		break;
  
  	case NFC_PROTO_MIFARE:
  		framing = NFC_DIGITAL_FRAMING_NFCA_T2T;
  		check_crc = digital_skb_check_crc_a;
  		add_crc = digital_skb_add_crc_a;
  		break;

  	case NFC_PROTO_FELICA:
  		framing = NFC_DIGITAL_FRAMING_NFCF_T3T;
  		check_crc = digital_skb_check_crc_f;
  		add_crc = digital_skb_add_crc_f;
  		break;

  	case NFC_PROTO_NFC_DEP:
  		if (rf_tech == NFC_DIGITAL_RF_TECH_106A) {
  			framing = NFC_DIGITAL_FRAMING_NFCA_NFC_DEP;
  			check_crc = digital_skb_check_crc_a;
  			add_crc = digital_skb_add_crc_a;
  		} else {
  			framing = NFC_DIGITAL_FRAMING_NFCF_NFC_DEP;
  			check_crc = digital_skb_check_crc_f;
  			add_crc = digital_skb_add_crc_f;
  		}
  		break;

  	case NFC_PROTO_ISO15693:

  		framing = NFC_DIGITAL_FRAMING_ISO15693_T5T;

  		check_crc = digital_skb_check_crc_b;
  		add_crc = digital_skb_add_crc_b;

  		break;

  
  	case NFC_PROTO_ISO14443:
  		framing = NFC_DIGITAL_FRAMING_NFCA_T4T;
  		check_crc = digital_skb_check_crc_a;
  		add_crc = digital_skb_add_crc_a;

  		break;

  	case NFC_PROTO_ISO14443_B:
  		framing = NFC_DIGITAL_FRAMING_NFCB_T4T;
  		check_crc = digital_skb_check_crc_b;
  		add_crc = digital_skb_add_crc_b;
  		break;

  	default:

  		pr_err("Invalid protocol %d
  ", protocol);

  		return -EINVAL;
  	}

  	pr_debug("rf_tech=%d, protocol=%d
  ", rf_tech, protocol);

  
  	ddev->curr_rf_tech = rf_tech;

  
  	if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
  		ddev->skb_add_crc = digital_skb_add_crc_none;
  		ddev->skb_check_crc = digital_skb_check_crc_none;
  	} else {
  		ddev->skb_add_crc = add_crc;
  		ddev->skb_check_crc = check_crc;
  	}
  
  	rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING, framing);
  	if (rc)
  		return rc;
  
  	target->supported_protocols = (1 << protocol);

  	poll_tech_count = ddev->poll_tech_count;

  	ddev->poll_tech_count = 0;

  	rc = nfc_targets_found(ddev->nfc_dev, target, 1);
  	if (rc) {
  		ddev->poll_tech_count = poll_tech_count;
  		return rc;
  	}

  	return 0;
  }

  void digital_poll_next_tech(struct nfc_digital_dev *ddev)
  {

  	u8 rand_mod;

  	digital_switch_rf(ddev, 0);
  
  	mutex_lock(&ddev->poll_lock);
  
  	if (!ddev->poll_tech_count) {
  		mutex_unlock(&ddev->poll_lock);
  		return;
  	}

  	get_random_bytes(&rand_mod, sizeof(rand_mod));
  	ddev->poll_tech_index = rand_mod % ddev->poll_tech_count;

  
  	mutex_unlock(&ddev->poll_lock);

  	schedule_delayed_work(&ddev->poll_work,
  			      msecs_to_jiffies(DIGITAL_POLL_INTERVAL));

  }
  
  static void digital_wq_poll(struct work_struct *work)
  {
  	int rc;
  	struct digital_poll_tech *poll_tech;
  	struct nfc_digital_dev *ddev = container_of(work,
  						    struct nfc_digital_dev,

  						    poll_work.work);

  	mutex_lock(&ddev->poll_lock);
  
  	if (!ddev->poll_tech_count) {
  		mutex_unlock(&ddev->poll_lock);
  		return;
  	}
  
  	poll_tech = &ddev->poll_techs[ddev->poll_tech_index];
  
  	mutex_unlock(&ddev->poll_lock);
  
  	rc = poll_tech->poll_func(ddev, poll_tech->rf_tech);
  	if (rc)
  		digital_poll_next_tech(ddev);
  }
  
  static void digital_add_poll_tech(struct nfc_digital_dev *ddev, u8 rf_tech,
  				  digital_poll_t poll_func)
  {
  	struct digital_poll_tech *poll_tech;
  
  	if (ddev->poll_tech_count >= NFC_DIGITAL_POLL_MODE_COUNT_MAX)
  		return;
  
  	poll_tech = &ddev->poll_techs[ddev->poll_tech_count++];
  
  	poll_tech->rf_tech = rf_tech;
  	poll_tech->poll_func = poll_func;
  }
  
  /**
   * start_poll operation
   *
   * For every supported protocol, the corresponding polling function is added
   * to the table of polling technologies (ddev->poll_techs[]) using
   * digital_add_poll_tech().
   * When a polling function fails (by timeout or protocol error) the next one is
   * schedule by digital_poll_next_tech() on the poll workqueue (ddev->poll_work).
   */

  static int digital_start_poll(struct nfc_dev *nfc_dev, __u32 im_protocols,
  			      __u32 tm_protocols)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
  	u32 matching_im_protocols, matching_tm_protocols;

  	pr_debug("protocols: im 0x%x, tm 0x%x, supported 0x%x
  ", im_protocols,

  		 tm_protocols, ddev->protocols);

  
  	matching_im_protocols = ddev->protocols & im_protocols;
  	matching_tm_protocols = ddev->protocols & tm_protocols;
  
  	if (!matching_im_protocols && !matching_tm_protocols) {

  		pr_err("Unknown protocol
  ");

  		return -EINVAL;
  	}
  
  	if (ddev->poll_tech_count) {

  		pr_err("Already polling
  ");

  		return -EBUSY;
  	}
  
  	if (ddev->curr_protocol) {

  		pr_err("A target is already active
  ");

  		return -EBUSY;
  	}
  
  	ddev->poll_tech_count = 0;
  	ddev->poll_tech_index = 0;
  
  	if (matching_im_protocols & DIGITAL_PROTO_NFCA_RF_TECH)
  		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106A,
  				      digital_in_send_sens_req);

  	if (matching_im_protocols & DIGITAL_PROTO_NFCB_RF_TECH)
  		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106B,
  				      digital_in_send_sensb_req);

  	if (matching_im_protocols & DIGITAL_PROTO_NFCF_RF_TECH) {

  		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_212F,
  				      digital_in_send_sensf_req);
  
  		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_424F,
  				      digital_in_send_sensf_req);
  	}

  	if (matching_im_protocols & DIGITAL_PROTO_ISO15693_RF_TECH)
  		digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_ISO15693,
  				      digital_in_send_iso15693_inv_req);

  	if (matching_tm_protocols & NFC_PROTO_NFC_DEP_MASK) {

  		if (ddev->ops->tg_listen_mdaa) {
  			digital_add_poll_tech(ddev, 0,
  					      digital_tg_listen_mdaa);

  		} else if (ddev->ops->tg_listen_md) {
  			digital_add_poll_tech(ddev, 0,
  					      digital_tg_listen_md);

  		} else {
  			digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_106A,
  					      digital_tg_listen_nfca);
  
  			digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_212F,
  					      digital_tg_listen_nfcf);
  
  			digital_add_poll_tech(ddev, NFC_DIGITAL_RF_TECH_424F,
  					      digital_tg_listen_nfcf);
  		}
  	}

  	if (!ddev->poll_tech_count) {

  		pr_err("Unsupported protocols: im=0x%x, tm=0x%x
  ",

  		       matching_im_protocols, matching_tm_protocols);
  		return -EINVAL;
  	}

  	schedule_delayed_work(&ddev->poll_work, 0);

  
  	return 0;

  }
  
  static void digital_stop_poll(struct nfc_dev *nfc_dev)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
  
  	mutex_lock(&ddev->poll_lock);
  
  	if (!ddev->poll_tech_count) {

  		pr_err("Polling operation was not running
  ");

  		mutex_unlock(&ddev->poll_lock);
  		return;
  	}
  
  	ddev->poll_tech_count = 0;
  
  	mutex_unlock(&ddev->poll_lock);

  	cancel_delayed_work_sync(&ddev->poll_work);

  
  	digital_abort_cmd(ddev);

  }
  
  static int digital_dev_up(struct nfc_dev *nfc_dev)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
  
  	digital_switch_rf(ddev, 1);
  
  	return 0;

  }
  
  static int digital_dev_down(struct nfc_dev *nfc_dev)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
  
  	digital_switch_rf(ddev, 0);
  
  	return 0;

  }
  
  static int digital_dep_link_up(struct nfc_dev *nfc_dev,
  			       struct nfc_target *target,
  			       __u8 comm_mode, __u8 *gb, size_t gb_len)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);

  	int rc;
  
  	rc = digital_in_send_atr_req(ddev, target, comm_mode, gb, gb_len);

  	if (!rc)
  		ddev->curr_protocol = NFC_PROTO_NFC_DEP;
  
  	return rc;

  }
  
  static int digital_dep_link_down(struct nfc_dev *nfc_dev)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);

  	digital_abort_cmd(ddev);

  	ddev->curr_protocol = 0;
  
  	return 0;

  }
  
  static int digital_activate_target(struct nfc_dev *nfc_dev,
  				   struct nfc_target *target, __u32 protocol)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
  
  	if (ddev->poll_tech_count) {
  		pr_err("Can't activate a target while polling
  ");
  		return -EBUSY;
  	}
  
  	if (ddev->curr_protocol) {
  		pr_err("A target is already active
  ");
  		return -EBUSY;
  	}
  
  	ddev->curr_protocol = protocol;

  	return 0;

  }
  
  static void digital_deactivate_target(struct nfc_dev *nfc_dev,

  				      struct nfc_target *target,
  				      u8 mode)

  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);

  	if (!ddev->curr_protocol) {
  		pr_err("No active target
  ");
  		return;
  	}

  	ddev->curr_protocol = 0;

  }
  
  static int digital_tg_send(struct nfc_dev *dev, struct sk_buff *skb)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(dev);
  
  	return digital_tg_send_dep_res(ddev, skb);

  }

  static void digital_in_send_complete(struct nfc_digital_dev *ddev, void *arg,
  				     struct sk_buff *resp)
  {
  	struct digital_data_exch *data_exch = arg;
  	int rc;
  
  	if (IS_ERR(resp)) {
  		rc = PTR_ERR(resp);

  		resp = NULL;

  		goto done;
  	}

  	if (ddev->curr_protocol == NFC_PROTO_MIFARE) {

  		rc = digital_in_recv_mifare_res(resp);

  		/* crc check is done in digital_in_recv_mifare_res() */
  		goto done;
  	}

  	if ((ddev->curr_protocol == NFC_PROTO_ISO14443) ||
  	    (ddev->curr_protocol == NFC_PROTO_ISO14443_B)) {

  		rc = digital_in_iso_dep_pull_sod(ddev, resp);
  		if (rc)
  			goto done;
  	}
  
  	rc = ddev->skb_check_crc(resp);

  done:

  	if (rc) {
  		kfree_skb(resp);
  		resp = NULL;
  	}

  	data_exch->cb(data_exch->cb_context, resp, rc);
  
  	kfree(data_exch);
  }

  static int digital_in_send(struct nfc_dev *nfc_dev, struct nfc_target *target,
  			   struct sk_buff *skb, data_exchange_cb_t cb,
  			   void *cb_context)
  {

  	struct nfc_digital_dev *ddev = nfc_get_drvdata(nfc_dev);
  	struct digital_data_exch *data_exch;

  	int rc;

  	data_exch = kzalloc(sizeof(*data_exch), GFP_KERNEL);

  	if (!data_exch)

  		return -ENOMEM;

  
  	data_exch->cb = cb;
  	data_exch->cb_context = cb_context;

  	if (ddev->curr_protocol == NFC_PROTO_NFC_DEP) {
  		rc = digital_in_send_dep_req(ddev, target, skb, data_exch);
  		goto exit;
  	}

  	if ((ddev->curr_protocol == NFC_PROTO_ISO14443) ||
  	    (ddev->curr_protocol == NFC_PROTO_ISO14443_B)) {

  		rc = digital_in_iso_dep_push_sod(ddev, skb);
  		if (rc)

  			goto exit;

  	}

  	ddev->skb_add_crc(skb);

  	rc = digital_in_send_cmd(ddev, skb, 500, digital_in_send_complete,
  				 data_exch);
  
  exit:
  	if (rc)
  		kfree(data_exch);
  
  	return rc;

  }
  
  static struct nfc_ops digital_nfc_ops = {
  	.dev_up = digital_dev_up,
  	.dev_down = digital_dev_down,
  	.start_poll = digital_start_poll,
  	.stop_poll = digital_stop_poll,
  	.dep_link_up = digital_dep_link_up,
  	.dep_link_down = digital_dep_link_down,
  	.activate_target = digital_activate_target,
  	.deactivate_target = digital_deactivate_target,
  	.tm_send = digital_tg_send,
  	.im_transceive = digital_in_send,
  };
  
  struct nfc_digital_dev *nfc_digital_allocate_device(struct nfc_digital_ops *ops,
  					    __u32 supported_protocols,
  					    __u32 driver_capabilities,
  					    int tx_headroom, int tx_tailroom)
  {
  	struct nfc_digital_dev *ddev;
  
  	if (!ops->in_configure_hw || !ops->in_send_cmd || !ops->tg_listen ||
  	    !ops->tg_configure_hw || !ops->tg_send_cmd || !ops->abort_cmd ||

  	    !ops->switch_rf || (ops->tg_listen_md && !ops->tg_get_rf_tech))

  		return NULL;

  	ddev = kzalloc(sizeof(*ddev), GFP_KERNEL);

  	if (!ddev)

  		return NULL;

  
  	ddev->driver_capabilities = driver_capabilities;
  	ddev->ops = ops;

  	mutex_init(&ddev->cmd_lock);
  	INIT_LIST_HEAD(&ddev->cmd_queue);
  
  	INIT_WORK(&ddev->cmd_work, digital_wq_cmd);
  	INIT_WORK(&ddev->cmd_complete_work, digital_wq_cmd_complete);
  
  	mutex_init(&ddev->poll_lock);

  	INIT_DELAYED_WORK(&ddev->poll_work, digital_wq_poll);

  
  	if (supported_protocols & NFC_PROTO_JEWEL_MASK)
  		ddev->protocols |= NFC_PROTO_JEWEL_MASK;
  	if (supported_protocols & NFC_PROTO_MIFARE_MASK)
  		ddev->protocols |= NFC_PROTO_MIFARE_MASK;

  	if (supported_protocols & NFC_PROTO_FELICA_MASK)
  		ddev->protocols |= NFC_PROTO_FELICA_MASK;

  	if (supported_protocols & NFC_PROTO_NFC_DEP_MASK)
  		ddev->protocols |= NFC_PROTO_NFC_DEP_MASK;

  	if (supported_protocols & NFC_PROTO_ISO15693_MASK)
  		ddev->protocols |= NFC_PROTO_ISO15693_MASK;

  	if (supported_protocols & NFC_PROTO_ISO14443_MASK)
  		ddev->protocols |= NFC_PROTO_ISO14443_MASK;

  	if (supported_protocols & NFC_PROTO_ISO14443_B_MASK)
  		ddev->protocols |= NFC_PROTO_ISO14443_B_MASK;

  
  	ddev->tx_headroom = tx_headroom + DIGITAL_MAX_HEADER_LEN;
  	ddev->tx_tailroom = tx_tailroom + DIGITAL_CRC_LEN;

  
  	ddev->nfc_dev = nfc_allocate_device(&digital_nfc_ops, ddev->protocols,
  					    ddev->tx_headroom,
  					    ddev->tx_tailroom);
  	if (!ddev->nfc_dev) {

  		pr_err("nfc_allocate_device failed
  ");

  		goto free_dev;
  	}
  
  	nfc_set_drvdata(ddev->nfc_dev, ddev);
  
  	return ddev;
  
  free_dev:
  	kfree(ddev);
  
  	return NULL;
  }
  EXPORT_SYMBOL(nfc_digital_allocate_device);
  
  void nfc_digital_free_device(struct nfc_digital_dev *ddev)
  {
  	nfc_free_device(ddev->nfc_dev);

  	kfree(ddev);
  }
  EXPORT_SYMBOL(nfc_digital_free_device);
  
  int nfc_digital_register_device(struct nfc_digital_dev *ddev)
  {
  	return nfc_register_device(ddev->nfc_dev);
  }
  EXPORT_SYMBOL(nfc_digital_register_device);
  
  void nfc_digital_unregister_device(struct nfc_digital_dev *ddev)
  {

  	struct digital_cmd *cmd, *n;

  	nfc_unregister_device(ddev->nfc_dev);

  
  	mutex_lock(&ddev->poll_lock);
  	ddev->poll_tech_count = 0;
  	mutex_unlock(&ddev->poll_lock);

  	cancel_delayed_work_sync(&ddev->poll_work);

  	cancel_work_sync(&ddev->cmd_work);
  	cancel_work_sync(&ddev->cmd_complete_work);
  
  	list_for_each_entry_safe(cmd, n, &ddev->cmd_queue, queue) {
  		list_del(&cmd->queue);

  
  		/* Call the command callback if any and pass it a ENODEV error.
  		 * This gives a chance to the command issuer to free any
  		 * allocated buffer.
  		 */
  		if (cmd->cmd_cb)
  			cmd->cmd_cb(ddev, cmd->cb_context, ERR_PTR(-ENODEV));

  		kfree(cmd->mdaa_params);

  		kfree(cmd);
  	}

  }
  EXPORT_SYMBOL(nfc_digital_unregister_device);
  
  MODULE_LICENSE("GPL");