/*
 * Copyright (C) 2012  Intel Corporation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * 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) "hci: %s: " fmt, __func__

#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/nfc.h>

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

#include "hci.h"

/* Largest headroom needed for outgoing HCI commands */
#define HCI_CMDS_HEADROOM 1

int nfc_hci_result_to_errno(u8 result)
{
        switch (result) {
        case NFC_HCI_ANY_OK:
                return 0;
        case NFC_HCI_ANY_E_REG_PAR_UNKNOWN:
                return -EOPNOTSUPP;
        case NFC_HCI_ANY_E_TIMEOUT:
                return -ETIME;
        default:
                return -1;
        }
}
EXPORT_SYMBOL(nfc_hci_result_to_errno);

void nfc_hci_reset_pipes(struct nfc_hci_dev *hdev)
{
        int i = 0;

        for (i = 0; i < NFC_HCI_MAX_PIPES; i++) {
                hdev->pipes[i].gate = NFC_HCI_INVALID_GATE;
                hdev->pipes[i].dest_host = NFC_HCI_INVALID_HOST;
        }
        memset(hdev->gate2pipe, NFC_HCI_INVALID_PIPE, sizeof(hdev->gate2pipe));
}
EXPORT_SYMBOL(nfc_hci_reset_pipes);

void nfc_hci_reset_pipes_per_host(struct nfc_hci_dev *hdev, u8 host)
{
        int i = 0;

        for (i = 0; i < NFC_HCI_MAX_PIPES; i++) {
                if (hdev->pipes[i].dest_host != host)
                        continue;

                hdev->pipes[i].gate = NFC_HCI_INVALID_GATE;
                hdev->pipes[i].dest_host = NFC_HCI_INVALID_HOST;
        }
}
EXPORT_SYMBOL(nfc_hci_reset_pipes_per_host);

static void nfc_hci_msg_tx_work(struct work_struct *work)
{
        struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
                                                msg_tx_work);
        struct hci_msg *msg;
        struct sk_buff *skb;
        int r = 0;

        mutex_lock(&hdev->msg_tx_mutex);
        if (hdev->shutting_down)
                goto exit;

        if (hdev->cmd_pending_msg) {
                if (timer_pending(&hdev->cmd_timer) == 0) {
                        if (hdev->cmd_pending_msg->cb)
                                hdev->cmd_pending_msg->cb(hdev->
                                                          cmd_pending_msg->
                                                          cb_context,
                                                          NULL,
                                                          -ETIME);
                        kfree(hdev->cmd_pending_msg);
                        hdev->cmd_pending_msg = NULL;
                } else {
                        goto exit;
                }
        }

next_msg:
        if (list_empty(&hdev->msg_tx_queue))
                goto exit;

        msg = list_first_entry(&hdev->msg_tx_queue, struct hci_msg, msg_l);
        list_del(&msg->msg_l);

        pr_debug("msg_tx_queue has a cmd to send\n");
        while ((skb = skb_dequeue(&msg->msg_frags)) != NULL) {
                r = nfc_llc_xmit_from_hci(hdev->llc, skb);
                if (r < 0) {
                        kfree_skb(skb);
                        skb_queue_purge(&msg->msg_frags);
                        if (msg->cb)
                                msg->cb(msg->cb_context, NULL, r);
                        kfree(msg);
                        break;
                }
        }

        if (r)
                goto next_msg;

        if (msg->wait_response == false) {
                kfree(msg);
                goto next_msg;
        }

        hdev->cmd_pending_msg = msg;
        mod_timer(&hdev->cmd_timer, jiffies +
                  msecs_to_jiffies(hdev->cmd_pending_msg->completion_delay));

exit:
        mutex_unlock(&hdev->msg_tx_mutex);
}

static void nfc_hci_msg_rx_work(struct work_struct *work)
{
        struct nfc_hci_dev *hdev = container_of(work, struct nfc_hci_dev,
                                                msg_rx_work);
        struct sk_buff *skb;
        struct hcp_message *message;
        u8 pipe;
        u8 type;
        u8 instruction;

        while ((skb = skb_dequeue(&hdev->msg_rx_queue)) != NULL) {
                pipe = skb->data[0];
                skb_pull(skb, NFC_HCI_HCP_PACKET_HEADER_LEN);
                message = (struct hcp_message *)skb->data;
                type = HCP_MSG_GET_TYPE(message->header);
                instruction = HCP_MSG_GET_CMD(message->header);
                skb_pull(skb, NFC_HCI_HCP_MESSAGE_HEADER_LEN);

                nfc_hci_hcp_message_rx(hdev, pipe, type, instruction, skb);
        }
}

static void __nfc_hci_cmd_completion(struct nfc_hci_dev *hdev, int err,
                                     struct sk_buff *skb)
{
        del_timer_sync(&hdev->cmd_timer);

        if (hdev->cmd_pending_msg->cb)
                hdev->cmd_pending_msg->cb(hdev->cmd_pending_msg->cb_context,
                                          skb, err);
        else
                kfree_skb(skb);

        kfree(hdev->cmd_pending_msg);
        hdev->cmd_pending_msg = NULL;

        schedule_work(&hdev->msg_tx_work);
}

void nfc_hci_resp_received(struct nfc_hci_dev *hdev, u8 result,
                           struct sk_buff *skb)
{
        mutex_lock(&hdev->msg_tx_mutex);

        if (hdev->cmd_pending_msg == NULL) {
                kfree_skb(skb);
                goto exit;
        }

        __nfc_hci_cmd_completion(hdev, nfc_hci_result_to_errno(result), skb);

exit:
        mutex_unlock(&hdev->msg_tx_mutex);
}

void nfc_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
                          struct sk_buff *skb)
{
        u8 gate = hdev->pipes[pipe].gate;
        u8 status = NFC_HCI_ANY_OK;
        struct hci_create_pipe_resp *create_info;
        struct hci_delete_pipe_noti *delete_info;
        struct hci_all_pipe_cleared_noti *cleared_info;

        pr_debug("from gate %x pipe %x cmd %x\n", gate, pipe, cmd);

        switch (cmd) {
        case NFC_HCI_ADM_NOTIFY_PIPE_CREATED:
                if (skb->len != 5) {
                        status = NFC_HCI_ANY_E_NOK;
                        goto exit;
                }
                create_info = (struct hci_create_pipe_resp *)skb->data;

                if (create_info->pipe >= NFC_HCI_MAX_PIPES) {
                        status = NFC_HCI_ANY_E_NOK;
                        goto exit;
                }

                /* Save the new created pipe and bind with local gate,
                 * the description for skb->data[3] is destination gate id
                 * but since we received this cmd from host controller, we
                 * are the destination and it is our local gate
                 */
                hdev->gate2pipe[create_info->dest_gate] = create_info->pipe;
                hdev->pipes[create_info->pipe].gate = create_info->dest_gate;
                hdev->pipes[create_info->pipe].dest_host =
                                                        create_info->src_host;
                break;
        case NFC_HCI_ANY_OPEN_PIPE:
                if (gate == NFC_HCI_INVALID_GATE) {
                        status = NFC_HCI_ANY_E_NOK;
                        goto exit;
                }
                break;
        case NFC_HCI_ADM_NOTIFY_PIPE_DELETED:
                if (skb->len != 1) {
                        status = NFC_HCI_ANY_E_NOK;
                        goto exit;
                }
                delete_info = (struct hci_delete_pipe_noti *)skb->data;

                if (delete_info->pipe >= NFC_HCI_MAX_PIPES) {
                        status = NFC_HCI_ANY_E_NOK;
                        goto exit;
                }

                hdev->pipes[delete_info->pipe].gate = NFC_HCI_INVALID_GATE;
                hdev->pipes[delete_info->pipe].dest_host = NFC_HCI_INVALID_HOST;
                break;
        case NFC_HCI_ADM_NOTIFY_ALL_PIPE_CLEARED:
                if (skb->len != 1) {
                        status = NFC_HCI_ANY_E_NOK;
                        goto exit;
                }
                cleared_info = (struct hci_all_pipe_cleared_noti *)skb->data;

                nfc_hci_reset_pipes_per_host(hdev, cleared_info->host);
                break;
        default:
                pr_info("Discarded unknown cmd %x to gate %x\n", cmd, gate);
                break;
        }

        if (hdev->ops->cmd_received)
                hdev->ops->cmd_received(hdev, pipe, cmd, skb);

exit:
        nfc_hci_hcp_message_tx(hdev, pipe, NFC_HCI_HCP_RESPONSE,
                               status, NULL, 0, NULL, NULL, 0);

        kfree_skb(skb);
}

u32 nfc_hci_sak_to_protocol(u8 sak)
{
        switch (NFC_HCI_TYPE_A_SEL_PROT(sak)) {
        case NFC_HCI_TYPE_A_SEL_PROT_MIFARE:
                return NFC_PROTO_MIFARE_MASK;
        case NFC_HCI_TYPE_A_SEL_PROT_ISO14443:
                return NFC_PROTO_ISO14443_MASK;
        case NFC_HCI_TYPE_A_SEL_PROT_DEP:
                return NFC_PROTO_NFC_DEP_MASK;
        case NFC_HCI_TYPE_A_SEL_PROT_ISO14443_DEP:
                return NFC_PROTO_ISO14443_MASK | NFC_PROTO_NFC_DEP_MASK;
        default:
                return 0xffffffff;
        }
}
EXPORT_SYMBOL(nfc_hci_sak_to_protocol);

int nfc_hci_target_discovered(struct nfc_hci_dev *hdev, u8 gate)
{
        struct nfc_target *targets;
        struct sk_buff *atqa_skb = NULL;
        struct sk_buff *sak_skb = NULL;
        struct sk_buff *uid_skb = NULL;
        int r;

        pr_debug("from gate %d\n", gate);

        targets = kzalloc(sizeof(struct nfc_target), GFP_KERNEL);
        if (targets == NULL)
                return -ENOMEM;

        switch (gate) {
        case NFC_HCI_RF_READER_A_GATE:
                r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
                                      NFC_HCI_RF_READER_A_ATQA, &atqa_skb);
                if (r < 0)
                        goto exit;

                r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
                                      NFC_HCI_RF_READER_A_SAK, &sak_skb);
                if (r < 0)
                        goto exit;

                if (atqa_skb->len != 2 || sak_skb->len != 1) {
                        r = -EPROTO;
                        goto exit;
                }

                targets->supported_protocols =
                                nfc_hci_sak_to_protocol(sak_skb->data[0]);
                if (targets->supported_protocols == 0xffffffff) {
                        r = -EPROTO;
                        goto exit;
                }

                targets->sens_res = be16_to_cpu(*(__be16 *)atqa_skb->data);
                targets->sel_res = sak_skb->data[0];

                r = nfc_hci_get_param(hdev, NFC_HCI_RF_READER_A_GATE,
                                      NFC_HCI_RF_READER_A_UID, &uid_skb);
                if (r < 0)
                        goto exit;

                if (uid_skb->len == 0 || uid_skb->len > NFC_NFCID1_MAXSIZE) {
                        r = -EPROTO;
                        goto exit;
                }

                memcpy(targets->nfcid1, uid_skb->data, uid_skb->len);
                targets->nfcid1_len = uid_skb->len;

                if (hdev->ops->complete_target_discovered) {
                        r = hdev->ops->complete_target_discovered(hdev, gate,
                                                                  targets);
                        if (r < 0)
                                goto exit;
                }
                break;
        case NFC_HCI_RF_READER_B_GATE:
                targets->supported_protocols = NFC_PROTO_ISO14443_B_MASK;
                break;
        default:
                if (hdev->ops->target_from_gate)
                        r = hdev->ops->target_from_gate(hdev, gate, targets);
                else
                        r = -EPROTO;
                if (r < 0)
                        goto exit;

                if (hdev->ops->complete_target_discovered) {
                        r = hdev->ops->complete_target_discovered(hdev, gate,
                                                                  targets);
                        if (r < 0)
                                goto exit;
                }
                break;
        }

        /* if driver set the new gate, we will skip the old one */
        if (targets->hci_reader_gate == 0x00)
                targets->hci_reader_gate = gate;

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

exit:
        kfree(targets);
        kfree_skb(atqa_skb);
        kfree_skb(sak_skb);
        kfree_skb(uid_skb);

        return r;
}
EXPORT_SYMBOL(nfc_hci_target_discovered);

void nfc_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe, u8 event,
                            struct sk_buff *skb)
{
        int r = 0;
        u8 gate = hdev->pipes[pipe].gate;

        if (gate == NFC_HCI_INVALID_GATE) {
                pr_err("Discarded event %x to unopened pipe %x\n", event, pipe);
                goto exit;
        }

        if (hdev->ops->event_received) {
                r = hdev->ops->event_received(hdev, pipe, event, skb);
                if (r <= 0)
                        goto exit_noskb;
        }

        switch (event) {
        case NFC_HCI_EVT_TARGET_DISCOVERED:
                if (skb->len < 1) {     /* no status data? */
                        r = -EPROTO;
                        goto exit;
                }

                if (skb->data[0] == 3) {
                        /* TODO: Multiple targets in field, none activated
                         * poll is supposedly stopped, but there is no
                         * single target to activate, so nothing to report
                         * up.
                         * if we need to restart poll, we must save the
                         * protocols from the initial poll and reuse here.
                         */
                }

                if (skb->data[0] != 0) {
                        r = -EPROTO;
                        goto exit;
                }

                r = nfc_hci_target_discovered(hdev, gate);
                break;
        default:
                pr_info("Discarded unknown event %x to gate %x\n", event, gate);
                r = -EINVAL;
                break;
        }

exit:
        kfree_skb(skb);

exit_noskb:
        if (r)
                nfc_hci_driver_failure(hdev, r);
}

static void nfc_hci_cmd_timeout(struct timer_list *t)
{
        struct nfc_hci_dev *hdev = from_timer(hdev, t, cmd_timer);

        schedule_work(&hdev->msg_tx_work);
}

static int hci_dev_connect_gates(struct nfc_hci_dev *hdev, u8 gate_count,
                                 struct nfc_hci_gate *gates)
{
        int r;
        while (gate_count--) {
                r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
                                         gates->gate, gates->pipe);
                if (r < 0)
                        return r;
                gates++;
        }

        return 0;
}

static int hci_dev_session_init(struct nfc_hci_dev *hdev)
{
        struct sk_buff *skb = NULL;
        int r;

        if (hdev->init_data.gates[0].gate != NFC_HCI_ADMIN_GATE)
                return -EPROTO;

        r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
                                 hdev->init_data.gates[0].gate,
                                 hdev->init_data.gates[0].pipe);
        if (r < 0)
                goto exit;

        r = nfc_hci_get_param(hdev, NFC_HCI_ADMIN_GATE,
                              NFC_HCI_ADMIN_SESSION_IDENTITY, &skb);
        if (r < 0)
                goto disconnect_all;

        if (skb->len && skb->len == strlen(hdev->init_data.session_id) &&
                (memcmp(hdev->init_data.session_id, skb->data,
                           skb->len) == 0) && hdev->ops->load_session) {
                /* Restore gate<->pipe table from some proprietary location. */

                r = hdev->ops->load_session(hdev);

                if (r < 0)
                        goto disconnect_all;
        } else {

                r = nfc_hci_disconnect_all_gates(hdev);
                if (r < 0)
                        goto exit;

                r = hci_dev_connect_gates(hdev, hdev->init_data.gate_count,
                                          hdev->init_data.gates);
                if (r < 0)
                        goto disconnect_all;

                r = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,
                                NFC_HCI_ADMIN_SESSION_IDENTITY,
                                hdev->init_data.session_id,
                                strlen(hdev->init_data.session_id));
        }
        if (r == 0)
                goto exit;

disconnect_all:
        nfc_hci_disconnect_all_gates(hdev);

exit:
        kfree_skb(skb);

        return r;
}

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

        r = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,
                              NFC_HCI_ID_MGMT_VERSION_SW, &skb);
        if (r == -EOPNOTSUPP) {
                pr_info("Software/Hardware info not available\n");
                return 0;
        }
        if (r < 0)
                return r;

        if (skb->len != 3) {
                kfree_skb(skb);
                return -EINVAL;
        }

        hdev->sw_romlib = (skb->data[0] & 0xf0) >> 4;
        hdev->sw_patch = skb->data[0] & 0x0f;
        hdev->sw_flashlib_major = skb->data[1];
        hdev->sw_flashlib_minor = skb->data[2];

        kfree_skb(skb);

        r = nfc_hci_get_param(hdev, NFC_HCI_ID_MGMT_GATE,
                              NFC_HCI_ID_MGMT_VERSION_HW, &skb);
        if (r < 0)
                return r;

        if (skb->len != 3) {
                kfree_skb(skb);
                return -EINVAL;
        }

        hdev->hw_derivative = (skb->data[0] & 0xe0) >> 5;
        hdev->hw_version = skb->data[0] & 0x1f;
        hdev->hw_mpw = (skb->data[1] & 0xc0) >> 6;
        hdev->hw_software = skb->data[1] & 0x3f;
        hdev->hw_bsid = skb->data[2];

        kfree_skb(skb);

        pr_info("SOFTWARE INFO:\n");
        pr_info("RomLib         : %d\n", hdev->sw_romlib);
        pr_info("Patch          : %d\n", hdev->sw_patch);
        pr_info("FlashLib Major : %d\n", hdev->sw_flashlib_major);
        pr_info("FlashLib Minor : %d\n", hdev->sw_flashlib_minor);
        pr_info("HARDWARE INFO:\n");
        pr_info("Derivative     : %d\n", hdev->hw_derivative);
        pr_info("HW Version     : %d\n", hdev->hw_version);
        pr_info("#MPW           : %d\n", hdev->hw_mpw);
        pr_info("Software       : %d\n", hdev->hw_software);
        pr_info("BSID Version   : %d\n", hdev->hw_bsid);

        return 0;
}

static int hci_dev_up(struct nfc_dev *nfc_dev)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
        int r = 0;

        if (hdev->ops->open) {
                r = hdev->ops->open(hdev);
                if (r < 0)
                        return r;
        }

        r = nfc_llc_start(hdev->llc);
        if (r < 0)
                goto exit_close;

        r = hci_dev_session_init(hdev);
        if (r < 0)
                goto exit_llc;

        r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
                               NFC_HCI_EVT_END_OPERATION, NULL, 0);
        if (r < 0)
                goto exit_llc;

        if (hdev->ops->hci_ready) {
                r = hdev->ops->hci_ready(hdev);
                if (r < 0)
                        goto exit_llc;
        }

        r = hci_dev_version(hdev);
        if (r < 0)
                goto exit_llc;

        return 0;

exit_llc:
        nfc_llc_stop(hdev->llc);

exit_close:
        if (hdev->ops->close)
                hdev->ops->close(hdev);

        return r;
}

static int hci_dev_down(struct nfc_dev *nfc_dev)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        nfc_llc_stop(hdev->llc);

        if (hdev->ops->close)
                hdev->ops->close(hdev);

        nfc_hci_reset_pipes(hdev);

        return 0;
}

static int hci_start_poll(struct nfc_dev *nfc_dev,
                          u32 im_protocols, u32 tm_protocols)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (hdev->ops->start_poll)
                return hdev->ops->start_poll(hdev, im_protocols, tm_protocols);
        else
                return nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
                                          NFC_HCI_EVT_READER_REQUESTED,
                                          NULL, 0);
}

static void hci_stop_poll(struct nfc_dev *nfc_dev)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (hdev->ops->stop_poll)
                hdev->ops->stop_poll(hdev);
        else
                nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
                                   NFC_HCI_EVT_END_OPERATION, NULL, 0);
}

static int hci_dep_link_up(struct nfc_dev *nfc_dev, struct nfc_target *target,
                                __u8 comm_mode, __u8 *gb, size_t gb_len)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (!hdev->ops->dep_link_up)
                return 0;

        return hdev->ops->dep_link_up(hdev, target, comm_mode,
                                      gb, gb_len);
}

static int hci_dep_link_down(struct nfc_dev *nfc_dev)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (!hdev->ops->dep_link_down)
                return 0;

        return hdev->ops->dep_link_down(hdev);
}

static int hci_activate_target(struct nfc_dev *nfc_dev,
                               struct nfc_target *target, u32 protocol)
{
        return 0;
}

static void hci_deactivate_target(struct nfc_dev *nfc_dev,
                                  struct nfc_target *target,
                                  u8 mode)
{
}

#define HCI_CB_TYPE_TRANSCEIVE 1

static void hci_transceive_cb(void *context, struct sk_buff *skb, int err)
{
        struct nfc_hci_dev *hdev = context;

        switch (hdev->async_cb_type) {
        case HCI_CB_TYPE_TRANSCEIVE:
                /*
                 * TODO: Check RF Error indicator to make sure data is valid.
                 * It seems that HCI cmd can complete without error, but data
                 * can be invalid if an RF error occured? Ignore for now.
                 */
                if (err == 0)
                        skb_trim(skb, skb->len - 1); /* RF Err ind */

                hdev->async_cb(hdev->async_cb_context, skb, err);
                break;
        default:
                if (err == 0)
                        kfree_skb(skb);
                break;
        }
}

static int hci_transceive(struct nfc_dev *nfc_dev, struct nfc_target *target,
                          struct sk_buff *skb, data_exchange_cb_t cb,
                          void *cb_context)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);
        int r;

        pr_debug("target_idx=%d\n", target->idx);

        switch (target->hci_reader_gate) {
        case NFC_HCI_RF_READER_A_GATE:
        case NFC_HCI_RF_READER_B_GATE:
                if (hdev->ops->im_transceive) {
                        r = hdev->ops->im_transceive(hdev, target, skb, cb,
                                                     cb_context);
                        if (r <= 0)     /* handled */
                                break;
                }

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

                hdev->async_cb_type = HCI_CB_TYPE_TRANSCEIVE;
                hdev->async_cb = cb;
                hdev->async_cb_context = cb_context;

                r = nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
                                           NFC_HCI_WR_XCHG_DATA, skb->data,
                                           skb->len, hci_transceive_cb, hdev);
                break;
        default:
                if (hdev->ops->im_transceive) {
                        r = hdev->ops->im_transceive(hdev, target, skb, cb,
                                                     cb_context);
                        if (r == 1)
                                r = -ENOTSUPP;
                } else {
                        r = -ENOTSUPP;
                }
                break;
        }

        kfree_skb(skb);

        return r;
}

static int hci_tm_send(struct nfc_dev *nfc_dev, struct sk_buff *skb)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (!hdev->ops->tm_send) {
                kfree_skb(skb);
                return -ENOTSUPP;
        }

        return hdev->ops->tm_send(hdev, skb);
}

static int hci_check_presence(struct nfc_dev *nfc_dev,
                              struct nfc_target *target)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (!hdev->ops->check_presence)
                return 0;

        return hdev->ops->check_presence(hdev, target);
}

static int hci_discover_se(struct nfc_dev *nfc_dev)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (hdev->ops->discover_se)
                return hdev->ops->discover_se(hdev);

        return 0;
}

static int hci_enable_se(struct nfc_dev *nfc_dev, u32 se_idx)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (hdev->ops->enable_se)
                return hdev->ops->enable_se(hdev, se_idx);

        return 0;
}

static int hci_disable_se(struct nfc_dev *nfc_dev, u32 se_idx)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (hdev->ops->disable_se)
                return hdev->ops->disable_se(hdev, se_idx);

        return 0;
}

static int hci_se_io(struct nfc_dev *nfc_dev, u32 se_idx,
                     u8 *apdu, size_t apdu_length,
                     se_io_cb_t cb, void *cb_context)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (hdev->ops->se_io)
                return hdev->ops->se_io(hdev, se_idx, apdu,
                                        apdu_length, cb, cb_context);

        return 0;
}

static void nfc_hci_failure(struct nfc_hci_dev *hdev, int err)
{
        mutex_lock(&hdev->msg_tx_mutex);

        if (hdev->cmd_pending_msg == NULL) {
                nfc_driver_failure(hdev->ndev, err);
                goto exit;
        }

        __nfc_hci_cmd_completion(hdev, err, NULL);

exit:
        mutex_unlock(&hdev->msg_tx_mutex);
}

static void nfc_hci_llc_failure(struct nfc_hci_dev *hdev, int err)
{
        nfc_hci_failure(hdev, err);
}

static void nfc_hci_recv_from_llc(struct nfc_hci_dev *hdev, struct sk_buff *skb)
{
        struct hcp_packet *packet;
        u8 type;
        u8 instruction;
        struct sk_buff *hcp_skb;
        u8 pipe;
        struct sk_buff *frag_skb;
        int msg_len;

        packet = (struct hcp_packet *)skb->data;
        if ((packet->header & ~NFC_HCI_FRAGMENT) == 0) {
                skb_queue_tail(&hdev->rx_hcp_frags, skb);
                return;
        }

        /* it's the last fragment. Does it need re-aggregation? */
        if (skb_queue_len(&hdev->rx_hcp_frags)) {
                pipe = packet->header & NFC_HCI_FRAGMENT;
                skb_queue_tail(&hdev->rx_hcp_frags, skb);

                msg_len = 0;
                skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
                        msg_len += (frag_skb->len -
                                    NFC_HCI_HCP_PACKET_HEADER_LEN);
                }

                hcp_skb = nfc_alloc_recv_skb(NFC_HCI_HCP_PACKET_HEADER_LEN +
                                             msg_len, GFP_KERNEL);
                if (hcp_skb == NULL) {
                        nfc_hci_failure(hdev, -ENOMEM);
                        return;
                }

                skb_put_u8(hcp_skb, pipe);

                skb_queue_walk(&hdev->rx_hcp_frags, frag_skb) {
                        msg_len = frag_skb->len - NFC_HCI_HCP_PACKET_HEADER_LEN;
                        skb_put_data(hcp_skb,
                                     frag_skb->data + NFC_HCI_HCP_PACKET_HEADER_LEN,
                                     msg_len);
                }

                skb_queue_purge(&hdev->rx_hcp_frags);
        } else {
                packet->header &= NFC_HCI_FRAGMENT;
                hcp_skb = skb;
        }

        /* if this is a response, dispatch immediately to
         * unblock waiting cmd context. Otherwise, enqueue to dispatch
         * in separate context where handler can also execute command.
         */
        packet = (struct hcp_packet *)hcp_skb->data;
        type = HCP_MSG_GET_TYPE(packet->message.header);
        if (type == NFC_HCI_HCP_RESPONSE) {
                pipe = packet->header;
                instruction = HCP_MSG_GET_CMD(packet->message.header);
                skb_pull(hcp_skb, NFC_HCI_HCP_PACKET_HEADER_LEN +
                         NFC_HCI_HCP_MESSAGE_HEADER_LEN);
                nfc_hci_hcp_message_rx(hdev, pipe, type, instruction, hcp_skb);
        } else {
                skb_queue_tail(&hdev->msg_rx_queue, hcp_skb);
                schedule_work(&hdev->msg_rx_work);
        }
}

static int hci_fw_download(struct nfc_dev *nfc_dev, const char *firmware_name)
{
        struct nfc_hci_dev *hdev = nfc_get_drvdata(nfc_dev);

        if (!hdev->ops->fw_download)
                return -ENOTSUPP;

        return hdev->ops->fw_download(hdev, firmware_name);
}

static struct nfc_ops hci_nfc_ops = {
        .dev_up = hci_dev_up,
        .dev_down = hci_dev_down,
        .start_poll = hci_start_poll,
        .stop_poll = hci_stop_poll,
        .dep_link_up = hci_dep_link_up,
        .dep_link_down = hci_dep_link_down,
        .activate_target = hci_activate_target,
        .deactivate_target = hci_deactivate_target,
        .im_transceive = hci_transceive,
        .tm_send = hci_tm_send,
        .check_presence = hci_check_presence,
        .fw_download = hci_fw_download,
        .discover_se = hci_discover_se,
        .enable_se = hci_enable_se,
        .disable_se = hci_disable_se,
        .se_io = hci_se_io,
};

struct nfc_hci_dev *nfc_hci_allocate_device(struct nfc_hci_ops *ops,
                                            struct nfc_hci_init_data *init_data,
                                            unsigned long quirks,
                                            u32 protocols,
                                            const char *llc_name,
                                            int tx_headroom,
                                            int tx_tailroom,
                                            int max_link_payload)
{
        struct nfc_hci_dev *hdev;

        if (ops->xmit == NULL)
                return NULL;

        if (protocols == 0)
                return NULL;

        hdev = kzalloc(sizeof(struct nfc_hci_dev), GFP_KERNEL);
        if (hdev == NULL)
                return NULL;

        hdev->llc = nfc_llc_allocate(llc_name, hdev, ops->xmit,
                                     nfc_hci_recv_from_llc, tx_headroom,
                                     tx_tailroom, nfc_hci_llc_failure);
        if (hdev->llc == NULL) {
                kfree(hdev);
                return NULL;
        }

        hdev->ndev = nfc_allocate_device(&hci_nfc_ops, protocols,
                                         tx_headroom + HCI_CMDS_HEADROOM,
                                         tx_tailroom);
        if (!hdev->ndev) {
                nfc_llc_free(hdev->llc);
                kfree(hdev);
                return NULL;
        }

        hdev->ops = ops;
        hdev->max_data_link_payload = max_link_payload;
        hdev->init_data = *init_data;

        nfc_set_drvdata(hdev->ndev, hdev);

        nfc_hci_reset_pipes(hdev);

        hdev->quirks = quirks;

        return hdev;
}
EXPORT_SYMBOL(nfc_hci_allocate_device);

void nfc_hci_free_device(struct nfc_hci_dev *hdev)
{
        nfc_free_device(hdev->ndev);
        nfc_llc_free(hdev->llc);
        kfree(hdev);
}
EXPORT_SYMBOL(nfc_hci_free_device);

int nfc_hci_register_device(struct nfc_hci_dev *hdev)
{
        mutex_init(&hdev->msg_tx_mutex);

        INIT_LIST_HEAD(&hdev->msg_tx_queue);

        INIT_WORK(&hdev->msg_tx_work, nfc_hci_msg_tx_work);

        timer_setup(&hdev->cmd_timer, nfc_hci_cmd_timeout, 0);

        skb_queue_head_init(&hdev->rx_hcp_frags);

        INIT_WORK(&hdev->msg_rx_work, nfc_hci_msg_rx_work);

        skb_queue_head_init(&hdev->msg_rx_queue);

        return nfc_register_device(hdev->ndev);
}
EXPORT_SYMBOL(nfc_hci_register_device);

void nfc_hci_unregister_device(struct nfc_hci_dev *hdev)
{
        struct hci_msg *msg, *n;

        mutex_lock(&hdev->msg_tx_mutex);

        if (hdev->cmd_pending_msg) {
                if (hdev->cmd_pending_msg->cb)
                        hdev->cmd_pending_msg->cb(
                                             hdev->cmd_pending_msg->cb_context,
                                             NULL, -ESHUTDOWN);
                kfree(hdev->cmd_pending_msg);
                hdev->cmd_pending_msg = NULL;
        }

        hdev->shutting_down = true;

        mutex_unlock(&hdev->msg_tx_mutex);

        del_timer_sync(&hdev->cmd_timer);
        cancel_work_sync(&hdev->msg_tx_work);

        cancel_work_sync(&hdev->msg_rx_work);

        nfc_unregister_device(hdev->ndev);

        skb_queue_purge(&hdev->rx_hcp_frags);
        skb_queue_purge(&hdev->msg_rx_queue);

        list_for_each_entry_safe(msg, n, &hdev->msg_tx_queue, msg_l) {
                list_del(&msg->msg_l);
                skb_queue_purge(&msg->msg_frags);
                kfree(msg);
        }
}
EXPORT_SYMBOL(nfc_hci_unregister_device);

void nfc_hci_set_clientdata(struct nfc_hci_dev *hdev, void *clientdata)
{
        hdev->clientdata = clientdata;
}
EXPORT_SYMBOL(nfc_hci_set_clientdata);

void *nfc_hci_get_clientdata(struct nfc_hci_dev *hdev)
{
        return hdev->clientdata;
}
EXPORT_SYMBOL(nfc_hci_get_clientdata);

void nfc_hci_driver_failure(struct nfc_hci_dev *hdev, int err)
{
        nfc_hci_failure(hdev, err);
}
EXPORT_SYMBOL(nfc_hci_driver_failure);

void nfc_hci_recv_frame(struct nfc_hci_dev *hdev, struct sk_buff *skb)
{
        nfc_llc_rcv_from_drv(hdev->llc, skb);
}
EXPORT_SYMBOL(nfc_hci_recv_frame);

static int __init nfc_hci_init(void)
{
        return nfc_llc_init();
}

static void __exit nfc_hci_exit(void)
{
        nfc_llc_exit();
}

subsys_initcall(nfc_hci_init);
module_exit(nfc_hci_exit);

MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("NFC HCI Core");