// SPDX-License-Identifier: GPL-2.0-only
/*
 * NFC Digital Protocol stack
 * Copyright (c) 2013, Intel Corporation.
 */

#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\n", cmd->type);
                return;
        }

        if (!rc)
                return;

        pr_err("in_send_command returned err %d\n", 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_obj(*cmd);
        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\n", 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\n", rc);

        return rc;
}

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

        params = kzalloc_obj(*params);
        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;

        rc = digital_send_cmd(ddev, DIGITAL_CMD_TG_LISTEN_MDAA, NULL, params,
                              500, digital_tg_recv_atr_req, NULL);
        if (rc)
                kfree(params);

        return rc;
}

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\n", protocol);
                return -EINVAL;
        }

        pr_debug("rf_tech=%d, protocol=%d\n", 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;
}

/**
 * digital_start_poll - start_poll operation
 * @nfc_dev: device to be polled
 * @im_protocols: bitset of nfc initiator protocols to be used for polling
 * @tm_protocols: bitset of nfc transport protocols to be used for polling
 *
 * 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\n", 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\n");
                return -EINVAL;
        }

        if (ddev->poll_tech_count) {
                pr_err("Already polling\n");
                return -EBUSY;
        }

        if (ddev->curr_protocol) {
                pr_err("A target is already active\n");
                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\n",
                       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\n");
                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\n");
                return -EBUSY;
        }

        if (ddev->curr_protocol) {
                pr_err("A target is already active\n");
                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\n");
                return;
        }

        digital_abort_cmd(ddev);
        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_obj(*data_exch);
        if (!data_exch) {
                kfree_skb(skb);
                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_skb(skb);
                kfree(data_exch);
        }

        return rc;
}

static const 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(const 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_obj(*ddev);
        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\n");
                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_DESCRIPTION("NFC Digital protocol stack");
MODULE_LICENSE("GPL");