// SPDX-License-Identifier: GPL-2.0-only
/*
 * HCI based Driver for STMicroelectronics NFC Chip
 *
 * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
 */

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

#include "st21nfca.h"

#define DRIVER_DESC "HCI NFC driver for ST21NFCA"

#define FULL_VERSION_LEN 3

/* Proprietary gates, events, commands and registers */

/* Commands that apply to all RF readers */
#define ST21NFCA_RF_READER_CMD_PRESENCE_CHECK   0x30

#define ST21NFCA_RF_READER_ISO15693_GATE        0x12
#define ST21NFCA_RF_READER_ISO15693_INVENTORY   0x01

/*
 * Reader gate for communication with contact-less cards using Type A
 * protocol ISO14443-3 but not compliant with ISO14443-4
 */
#define ST21NFCA_RF_READER_14443_3_A_GATE       0x15
#define ST21NFCA_RF_READER_14443_3_A_UID        0x02
#define ST21NFCA_RF_READER_14443_3_A_ATQA       0x03
#define ST21NFCA_RF_READER_14443_3_A_SAK        0x04

#define ST21NFCA_RF_READER_F_DATARATE           0x01
#define ST21NFCA_RF_READER_F_DATARATE_106       0x01
#define ST21NFCA_RF_READER_F_DATARATE_212       0x02
#define ST21NFCA_RF_READER_F_DATARATE_424       0x04
#define ST21NFCA_RF_READER_F_POL_REQ            0x02
#define ST21NFCA_RF_READER_F_POL_REQ_DEFAULT    0xffff0000
#define ST21NFCA_RF_READER_F_NFCID2             0x03
#define ST21NFCA_RF_READER_F_NFCID1             0x04

#define ST21NFCA_RF_CARD_F_MODE                 0x01
#define ST21NFCA_RF_CARD_F_NFCID2_LIST          0x04
#define ST21NFCA_RF_CARD_F_NFCID1               0x05
#define ST21NFCA_RF_CARD_F_SENS_RES             0x06
#define ST21NFCA_RF_CARD_F_SEL_RES              0x07
#define ST21NFCA_RF_CARD_F_DATARATE             0x08
#define ST21NFCA_RF_CARD_F_DATARATE_212_424     0x01

#define ST21NFCA_DEVICE_MGNT_PIPE               0x02

#define ST21NFCA_DM_GETINFO                     0x13
#define ST21NFCA_DM_GETINFO_PIPE_LIST           0x02
#define ST21NFCA_DM_GETINFO_PIPE_INFO           0x01
#define ST21NFCA_DM_PIPE_CREATED                0x02
#define ST21NFCA_DM_PIPE_OPEN                   0x04
#define ST21NFCA_DM_RF_ACTIVE                   0x80
#define ST21NFCA_DM_DISCONNECT                  0x30

#define ST21NFCA_DM_IS_PIPE_OPEN(p) \
        ((p & 0x0f) == (ST21NFCA_DM_PIPE_CREATED | ST21NFCA_DM_PIPE_OPEN))

#define ST21NFCA_NFC_MODE                       0x03    /* NFC_MODE parameter*/

#define ST21NFCA_EVT_HOT_PLUG                   0x03
#define ST21NFCA_EVT_HOT_PLUG_IS_INHIBITED(x) (x->data[0] & 0x80)

#define ST21NFCA_SE_TO_PIPES                    2000

static DECLARE_BITMAP(dev_mask, ST21NFCA_NUM_DEVICES);

static const struct nfc_hci_gate st21nfca_gates[] = {
        {NFC_HCI_ADMIN_GATE, NFC_HCI_ADMIN_PIPE},
        {NFC_HCI_LINK_MGMT_GATE, NFC_HCI_LINK_MGMT_PIPE},
        {ST21NFCA_DEVICE_MGNT_GATE, ST21NFCA_DEVICE_MGNT_PIPE},

        {NFC_HCI_LOOPBACK_GATE, NFC_HCI_INVALID_PIPE},
        {NFC_HCI_ID_MGMT_GATE, NFC_HCI_INVALID_PIPE},
        {NFC_HCI_RF_READER_B_GATE, NFC_HCI_INVALID_PIPE},
        {NFC_HCI_RF_READER_A_GATE, NFC_HCI_INVALID_PIPE},
        {ST21NFCA_RF_READER_F_GATE, NFC_HCI_INVALID_PIPE},
        {ST21NFCA_RF_READER_14443_3_A_GATE, NFC_HCI_INVALID_PIPE},
        {ST21NFCA_RF_READER_ISO15693_GATE, NFC_HCI_INVALID_PIPE},
        {ST21NFCA_RF_CARD_F_GATE, NFC_HCI_INVALID_PIPE},

        /* Secure element pipes are created by secure element host */
        {ST21NFCA_CONNECTIVITY_GATE, NFC_HCI_DO_NOT_CREATE_PIPE},
        {ST21NFCA_APDU_READER_GATE, NFC_HCI_DO_NOT_CREATE_PIPE},
};

struct st21nfca_pipe_info {
        u8 pipe_state;
        u8 src_host_id;
        u8 src_gate_id;
        u8 dst_host_id;
        u8 dst_gate_id;
} __packed;

/* Largest headroom needed for outgoing custom commands */
#define ST21NFCA_CMDS_HEADROOM  7

static int st21nfca_hci_load_session(struct nfc_hci_dev *hdev)
{
        int i, j, r;
        struct sk_buff *skb_pipe_list, *skb_pipe_info;
        struct st21nfca_pipe_info *info;

        u8 pipe_list[] = { ST21NFCA_DM_GETINFO_PIPE_LIST,
                NFC_HCI_TERMINAL_HOST_ID
        };
        u8 pipe_info[] = { ST21NFCA_DM_GETINFO_PIPE_INFO,
                NFC_HCI_TERMINAL_HOST_ID, 0
        };

        /* On ST21NFCA device pipes number are dynamics
         * A maximum of 16 pipes can be created at the same time
         * If pipes are already created, hci_dev_up will fail.
         * Doing a clear all pipe is a bad idea because:
         * - It does useless EEPROM cycling
         * - It might cause issue for secure elements support
         * (such as removing connectivity or APDU reader pipe)
         * A better approach on ST21NFCA is to:
         * - get a pipe list for each host.
         * (eg: NFC_HCI_HOST_CONTROLLER_ID for now).
         * (TODO Later on UICC HOST and eSE HOST)
         * - get pipe information
         * - match retrieved pipe list in st21nfca_gates
         * ST21NFCA_DEVICE_MGNT_GATE is a proprietary gate
         * with ST21NFCA_DEVICE_MGNT_PIPE.
         * Pipe can be closed and need to be open.
         */
        r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
                                ST21NFCA_DEVICE_MGNT_GATE,
                                ST21NFCA_DEVICE_MGNT_PIPE);
        if (r < 0)
                return r;

        /* Get pipe list */
        r = nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
                        ST21NFCA_DM_GETINFO, pipe_list, sizeof(pipe_list),
                        &skb_pipe_list);
        if (r < 0)
                return r;

        /* Complete the existing gate_pipe table */
        for (i = 0; i < skb_pipe_list->len; i++) {
                pipe_info[2] = skb_pipe_list->data[i];
                r = nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
                                        ST21NFCA_DM_GETINFO, pipe_info,
                                        sizeof(pipe_info), &skb_pipe_info);
                if (r)
                        continue;

                /*
                 * Match pipe ID and gate ID
                 * Output format from ST21NFC_DM_GETINFO is:
                 * - pipe state (1byte)
                 * - source hid (1byte)
                 * - source gid (1byte)
                 * - destination hid (1byte)
                 * - destination gid (1byte)
                 */
                info = (struct st21nfca_pipe_info *) skb_pipe_info->data;
                if (info->dst_gate_id == ST21NFCA_APDU_READER_GATE &&
                        info->src_host_id == NFC_HCI_UICC_HOST_ID) {
                        pr_err("Unexpected apdu_reader pipe on host %x\n",
                                info->src_host_id);
                        kfree_skb(skb_pipe_info);
                        continue;
                }

                for (j = 3; (j < ARRAY_SIZE(st21nfca_gates)) &&
                        (st21nfca_gates[j].gate != info->dst_gate_id) ; j++)
                        ;

                if (j < ARRAY_SIZE(st21nfca_gates) &&
                        st21nfca_gates[j].gate == info->dst_gate_id &&
                        ST21NFCA_DM_IS_PIPE_OPEN(info->pipe_state)) {
                        hdev->init_data.gates[j].pipe = pipe_info[2];

                        hdev->gate2pipe[st21nfca_gates[j].gate] =
                                                pipe_info[2];
                        hdev->pipes[pipe_info[2]].gate =
                                                st21nfca_gates[j].gate;
                        hdev->pipes[pipe_info[2]].dest_host =
                                                info->src_host_id;
                }
                kfree_skb(skb_pipe_info);
        }

        /*
         * 3 gates have a well known pipe ID. Only NFC_HCI_LINK_MGMT_GATE
         * is not yet open at this stage.
         */
        r = nfc_hci_connect_gate(hdev, NFC_HCI_HOST_CONTROLLER_ID,
                                 NFC_HCI_LINK_MGMT_GATE,
                                 NFC_HCI_LINK_MGMT_PIPE);

        kfree_skb(skb_pipe_list);
        return r;
}

static int st21nfca_hci_open(struct nfc_hci_dev *hdev)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
        int r;

        mutex_lock(&info->info_lock);

        if (info->state != ST21NFCA_ST_COLD) {
                r = -EBUSY;
                goto out;
        }

        r = info->phy_ops->enable(info->phy_id);

        if (r == 0)
                info->state = ST21NFCA_ST_READY;

out:
        mutex_unlock(&info->info_lock);
        return r;
}

static void st21nfca_hci_close(struct nfc_hci_dev *hdev)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        mutex_lock(&info->info_lock);

        if (info->state == ST21NFCA_ST_COLD)
                goto out;

        info->phy_ops->disable(info->phy_id);
        info->state = ST21NFCA_ST_COLD;

out:
        mutex_unlock(&info->info_lock);
}

static int st21nfca_hci_ready(struct nfc_hci_dev *hdev)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
        struct sk_buff *skb;

        u8 param;
        u8 white_list[2];
        int wl_size = 0;
        int r;

        if (info->se_status->is_uicc_present)
                white_list[wl_size++] = NFC_HCI_UICC_HOST_ID;
        if (info->se_status->is_ese_present)
                white_list[wl_size++] = ST21NFCA_ESE_HOST_ID;

        if (wl_size) {
                r = nfc_hci_set_param(hdev, NFC_HCI_ADMIN_GATE,
                                        NFC_HCI_ADMIN_WHITELIST,
                                        (u8 *) &white_list, wl_size);
                if (r < 0)
                        return r;
        }

        /* Set NFC_MODE in device management gate to enable */
        r = nfc_hci_get_param(hdev, ST21NFCA_DEVICE_MGNT_GATE,
                              ST21NFCA_NFC_MODE, &skb);
        if (r < 0)
                return r;

        param = skb->data[0];
        kfree_skb(skb);
        if (param == 0) {
                param = 1;

                r = nfc_hci_set_param(hdev, ST21NFCA_DEVICE_MGNT_GATE,
                                        ST21NFCA_NFC_MODE, &param, 1);
                if (r < 0)
                        return r;
        }

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

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

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

        print_hex_dump(KERN_DEBUG, "FULL VERSION SOFTWARE INFO: ",
                       DUMP_PREFIX_NONE, 16, 1,
                       skb->data, FULL_VERSION_LEN, false);

        kfree_skb(skb);

        return 0;
}

static int st21nfca_hci_xmit(struct nfc_hci_dev *hdev, struct sk_buff *skb)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

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

static int st21nfca_hci_start_poll(struct nfc_hci_dev *hdev,
                                   u32 im_protocols, u32 tm_protocols)
{
        int r;
        u32 pol_req;
        u8 param[19];
        struct sk_buff *datarate_skb;

        pr_info(DRIVER_DESC ": %s protocols 0x%x 0x%x\n",
                __func__, im_protocols, tm_protocols);

        r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
                               NFC_HCI_EVT_END_OPERATION, NULL, 0);
        if (r < 0)
                return r;
        if (im_protocols) {
                /*
                 * enable polling according to im_protocols & tm_protocols
                 * - CLOSE pipe according to im_protocols & tm_protocols
                 */
                if ((NFC_HCI_RF_READER_B_GATE & im_protocols) == 0) {
                        r = nfc_hci_disconnect_gate(hdev,
                                        NFC_HCI_RF_READER_B_GATE);
                        if (r < 0)
                                return r;
                }

                if ((NFC_HCI_RF_READER_A_GATE & im_protocols) == 0) {
                        r = nfc_hci_disconnect_gate(hdev,
                                        NFC_HCI_RF_READER_A_GATE);
                        if (r < 0)
                                return r;
                }

                if ((ST21NFCA_RF_READER_F_GATE & im_protocols) == 0) {
                        r = nfc_hci_disconnect_gate(hdev,
                                        ST21NFCA_RF_READER_F_GATE);
                        if (r < 0)
                                return r;
                } else {
                        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;
                        }

                        param[0] = ST21NFCA_RF_READER_F_DATARATE_106 |
                            ST21NFCA_RF_READER_F_DATARATE_212 |
                            ST21NFCA_RF_READER_F_DATARATE_424;
                        r = nfc_hci_set_param(hdev, ST21NFCA_RF_READER_F_GATE,
                                              ST21NFCA_RF_READER_F_DATARATE,
                                              param, 1);
                        if (r < 0)
                                return r;

                        pol_req = be32_to_cpu((__force __be32)
                                        ST21NFCA_RF_READER_F_POL_REQ_DEFAULT);
                        r = nfc_hci_set_param(hdev, ST21NFCA_RF_READER_F_GATE,
                                              ST21NFCA_RF_READER_F_POL_REQ,
                                              (u8 *) &pol_req, 4);
                        if (r < 0)
                                return r;
                }

                if ((ST21NFCA_RF_READER_14443_3_A_GATE & im_protocols) == 0) {
                        r = nfc_hci_disconnect_gate(hdev,
                                        ST21NFCA_RF_READER_14443_3_A_GATE);
                        if (r < 0)
                                return r;
                }

                if ((ST21NFCA_RF_READER_ISO15693_GATE & im_protocols) == 0) {
                        r = nfc_hci_disconnect_gate(hdev,
                                        ST21NFCA_RF_READER_ISO15693_GATE);
                        if (r < 0)
                                return r;
                }

                r = nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
                                       NFC_HCI_EVT_READER_REQUESTED, NULL, 0);
                if (r < 0)
                        nfc_hci_send_event(hdev, NFC_HCI_RF_READER_A_GATE,
                                           NFC_HCI_EVT_END_OPERATION, NULL, 0);
        }

        if (tm_protocols & NFC_PROTO_NFC_DEP_MASK) {
                r = nfc_hci_get_param(hdev, ST21NFCA_RF_CARD_F_GATE,
                                      ST21NFCA_RF_CARD_F_DATARATE,
                                      &datarate_skb);
                if (r < 0)
                        return r;

                /* Configure the maximum supported datarate to 424Kbps */
                if (datarate_skb->len > 0 &&
                    datarate_skb->data[0] !=
                    ST21NFCA_RF_CARD_F_DATARATE_212_424) {
                        param[0] = ST21NFCA_RF_CARD_F_DATARATE_212_424;
                        r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
                                              ST21NFCA_RF_CARD_F_DATARATE,
                                              param, 1);
                        if (r < 0) {
                                kfree_skb(datarate_skb);
                                return r;
                        }
                }
                kfree_skb(datarate_skb);

                /*
                 * Configure sens_res
                 *
                 * NFC Forum Digital Spec Table 7:
                 * NFCID1 size: triple (10 bytes)
                 */
                param[0] = 0x00;
                param[1] = 0x08;
                r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
                                      ST21NFCA_RF_CARD_F_SENS_RES, param, 2);
                if (r < 0)
                        return r;

                /*
                 * Configure sel_res
                 *
                 * NFC Forum Digistal Spec Table 17:
                 * b3 set to 0b (value b7-b6):
                 * - 10b: Configured for NFC-DEP Protocol
                 */
                param[0] = 0x40;
                r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
                                      ST21NFCA_RF_CARD_F_SEL_RES, param, 1);
                if (r < 0)
                        return r;

                /* Configure NFCID1 Random uid */
                r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
                                      ST21NFCA_RF_CARD_F_NFCID1, NULL, 0);
                if (r < 0)
                        return r;

                /* Configure NFCID2_LIST */
                /* System Code */
                param[0] = 0x00;
                param[1] = 0x00;
                /* NFCID2 */
                param[2] = 0x01;
                param[3] = 0xfe;
                param[4] = 'S';
                param[5] = 'T';
                param[6] = 'M';
                param[7] = 'i';
                param[8] = 'c';
                param[9] = 'r';
                /* 8 byte Pad bytes used for polling respone frame */

                /*
                 * Configuration byte:
                 * - bit 0: define the default NFCID2 entry used when the
                 * system code is equal to 'FFFF'
                 * - bit 1: use a random value for lowest 6 bytes of
                 * NFCID2 value
                 * - bit 2: ignore polling request frame if request code
                 * is equal to '01'
                 * - Other bits are RFU
                 */
                param[18] = 0x01;
                r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
                                      ST21NFCA_RF_CARD_F_NFCID2_LIST, param,
                                      19);
                if (r < 0)
                        return r;

                param[0] = 0x02;
                r = nfc_hci_set_param(hdev, ST21NFCA_RF_CARD_F_GATE,
                                      ST21NFCA_RF_CARD_F_MODE, param, 1);
        }

        return r;
}

static void st21nfca_hci_stop_poll(struct nfc_hci_dev *hdev)
{
        nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
                        ST21NFCA_DM_DISCONNECT, NULL, 0, NULL);
}

static int st21nfca_get_iso14443_3_atqa(struct nfc_hci_dev *hdev, u16 *atqa)
{
        int r;
        struct sk_buff *atqa_skb = NULL;

        r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_14443_3_A_GATE,
                              ST21NFCA_RF_READER_14443_3_A_ATQA, &atqa_skb);
        if (r < 0)
                goto exit;

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

        *atqa = be16_to_cpu(*(__be16 *) atqa_skb->data);

exit:
        kfree_skb(atqa_skb);
        return r;
}

static int st21nfca_get_iso14443_3_sak(struct nfc_hci_dev *hdev, u8 *sak)
{
        int r;
        struct sk_buff *sak_skb = NULL;

        r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_14443_3_A_GATE,
                              ST21NFCA_RF_READER_14443_3_A_SAK, &sak_skb);
        if (r < 0)
                goto exit;

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

        *sak = sak_skb->data[0];

exit:
        kfree_skb(sak_skb);
        return r;
}

static int st21nfca_get_iso14443_3_uid(struct nfc_hci_dev *hdev, u8 *uid,
                                       int *len)
{
        int r;
        struct sk_buff *uid_skb = NULL;

        r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_14443_3_A_GATE,
                              ST21NFCA_RF_READER_14443_3_A_UID, &uid_skb);
        if (r < 0)
                goto exit;

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

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

static int st21nfca_get_iso15693_inventory(struct nfc_hci_dev *hdev,
                                           struct nfc_target *target)
{
        int r;
        struct sk_buff *inventory_skb = NULL;

        r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_ISO15693_GATE,
                              ST21NFCA_RF_READER_ISO15693_INVENTORY,
                              &inventory_skb);
        if (r < 0)
                goto exit;

        skb_pull(inventory_skb, 2);

        if (inventory_skb->len == 0 ||
            inventory_skb->len > NFC_ISO15693_UID_MAXSIZE) {
                r = -EPROTO;
                goto exit;
        }

        memcpy(target->iso15693_uid, inventory_skb->data, inventory_skb->len);
        target->iso15693_dsfid  = inventory_skb->data[1];
        target->is_iso15693 = 1;
exit:
        kfree_skb(inventory_skb);
        return r;
}

static int st21nfca_hci_dep_link_up(struct nfc_hci_dev *hdev,
                                    struct nfc_target *target, u8 comm_mode,
                                    u8 *gb, size_t gb_len)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        info->dep_info.idx = target->idx;
        return st21nfca_im_send_atr_req(hdev, gb, gb_len);
}

static int st21nfca_hci_dep_link_down(struct nfc_hci_dev *hdev)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        info->state = ST21NFCA_ST_READY;

        return nfc_hci_send_cmd(hdev, ST21NFCA_DEVICE_MGNT_GATE,
                                ST21NFCA_DM_DISCONNECT, NULL, 0, NULL);
}

static int st21nfca_hci_target_from_gate(struct nfc_hci_dev *hdev, u8 gate,
                                         struct nfc_target *target)
{
        int r, len;
        u16 atqa;
        u8 sak;
        u8 uid[NFC_NFCID1_MAXSIZE];

        switch (gate) {
        case ST21NFCA_RF_READER_F_GATE:
                target->supported_protocols = NFC_PROTO_FELICA_MASK;
                break;
        case ST21NFCA_RF_READER_14443_3_A_GATE:
                /* ISO14443-3 type 1 or 2 tags */
                r = st21nfca_get_iso14443_3_atqa(hdev, &atqa);
                if (r < 0)
                        return r;
                if (atqa == 0x000c) {
                        target->supported_protocols = NFC_PROTO_JEWEL_MASK;
                        target->sens_res = 0x0c00;
                } else {
                        r = st21nfca_get_iso14443_3_sak(hdev, &sak);
                        if (r < 0)
                                return r;

                        r = st21nfca_get_iso14443_3_uid(hdev, uid, &len);
                        if (r < 0)
                                return r;

                        target->supported_protocols =
                            nfc_hci_sak_to_protocol(sak);
                        if (target->supported_protocols == 0xffffffff)
                                return -EPROTO;

                        target->sens_res = atqa;
                        target->sel_res = sak;
                        memcpy(target->nfcid1, uid, len);
                        target->nfcid1_len = len;
                }

                break;
        case ST21NFCA_RF_READER_ISO15693_GATE:
                target->supported_protocols = NFC_PROTO_ISO15693_MASK;
                r = st21nfca_get_iso15693_inventory(hdev, target);
                if (r < 0)
                        return r;
                break;
        default:
                return -EPROTO;
        }

        return 0;
}

static int st21nfca_hci_complete_target_discovered(struct nfc_hci_dev *hdev,
                                                u8 gate,
                                                struct nfc_target *target)
{
        int r;
        struct sk_buff *nfcid_skb = NULL;

        if (gate == ST21NFCA_RF_READER_F_GATE) {
                r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_F_GATE,
                                ST21NFCA_RF_READER_F_NFCID2, &nfcid_skb);
                if (r < 0)
                        goto exit;

                if (nfcid_skb->len > NFC_SENSF_RES_MAXSIZE) {
                        r = -EPROTO;
                        goto exit;
                }

                /*
                 * - After the recepton of polling response for type F frame
                 * at 212 or 424 Kbit/s, NFCID2 registry parameters will be
                 * updated.
                 * - After the reception of SEL_RES with NFCIP-1 compliant bit
                 * set for type A frame NFCID1 will be updated
                 */
                if (nfcid_skb->len > 0) {
                        /* P2P in type F */
                        memcpy(target->sensf_res, nfcid_skb->data,
                                nfcid_skb->len);
                        target->sensf_res_len = nfcid_skb->len;
                        /* NFC Forum Digital Protocol Table 44 */
                        if (target->sensf_res[0] == 0x01 &&
                            target->sensf_res[1] == 0xfe)
                                target->supported_protocols =
                                                        NFC_PROTO_NFC_DEP_MASK;
                        else
                                target->supported_protocols =
                                                        NFC_PROTO_FELICA_MASK;
                } else {
                        kfree_skb(nfcid_skb);
                        nfcid_skb = NULL;
                        /* P2P in type A */
                        r = nfc_hci_get_param(hdev, ST21NFCA_RF_READER_F_GATE,
                                        ST21NFCA_RF_READER_F_NFCID1,
                                        &nfcid_skb);
                        if (r < 0)
                                goto exit;

                        if (nfcid_skb->len > NFC_NFCID1_MAXSIZE) {
                                r = -EPROTO;
                                goto exit;
                        }
                        memcpy(target->sensf_res, nfcid_skb->data,
                                nfcid_skb->len);
                        target->sensf_res_len = nfcid_skb->len;
                        target->supported_protocols = NFC_PROTO_NFC_DEP_MASK;
                }
                target->hci_reader_gate = ST21NFCA_RF_READER_F_GATE;
        }
        r = 1;
exit:
        kfree_skb(nfcid_skb);
        return r;
}

#define ST21NFCA_CB_TYPE_READER_ISO15693 1
static void st21nfca_hci_data_exchange_cb(void *context, struct sk_buff *skb,
                                          int err)
{
        struct st21nfca_hci_info *info = context;

        switch (info->async_cb_type) {
        case ST21NFCA_CB_TYPE_READER_ISO15693:
                if (err == 0)
                        skb_trim(skb, skb->len - 1);
                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 st21nfca_hci_im_transceive(struct nfc_hci_dev *hdev,
                                      struct nfc_target *target,
                                      struct sk_buff *skb,
                                      data_exchange_cb_t cb, void *cb_context)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

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

        switch (target->hci_reader_gate) {
        case ST21NFCA_RF_READER_F_GATE:
                if (target->supported_protocols == NFC_PROTO_NFC_DEP_MASK)
                        return st21nfca_im_send_dep_req(hdev, skb);

                *(u8 *)skb_push(skb, 1) = 0x1a;
                return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
                                              ST21NFCA_WR_XCHG_DATA, skb->data,
                                              skb->len, cb, cb_context);
        case ST21NFCA_RF_READER_14443_3_A_GATE:
                *(u8 *)skb_push(skb, 1) = 0x1a; /* CTR, see spec:10.2.2.1 */

                return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
                                              ST21NFCA_WR_XCHG_DATA, skb->data,
                                              skb->len, cb, cb_context);
        case ST21NFCA_RF_READER_ISO15693_GATE:
                info->async_cb_type = ST21NFCA_CB_TYPE_READER_ISO15693;
                info->async_cb = cb;
                info->async_cb_context = cb_context;

                *(u8 *)skb_push(skb, 1) = 0x17;

                return nfc_hci_send_cmd_async(hdev, target->hci_reader_gate,
                                              ST21NFCA_WR_XCHG_DATA, skb->data,
                                              skb->len,
                                              st21nfca_hci_data_exchange_cb,
                                              info);
        default:
                return 1;
        }
}

static int st21nfca_hci_tm_send(struct nfc_hci_dev *hdev, struct sk_buff *skb)
{
        return st21nfca_tm_send_dep_res(hdev, skb);
}

static int st21nfca_hci_check_presence(struct nfc_hci_dev *hdev,
                                       struct nfc_target *target)
{
        u8 fwi = 0x11;

        switch (target->hci_reader_gate) {
        case NFC_HCI_RF_READER_A_GATE:
        case NFC_HCI_RF_READER_B_GATE:
                /*
                 * PRESENCE_CHECK on those gates is available
                 * However, the answer to this command is taking 3 * fwi
                 * if the card is no present.
                 * Instead, we send an empty I-Frame with a very short
                 * configurable fwi ~604µs.
                 */
                return nfc_hci_send_cmd(hdev, target->hci_reader_gate,
                                        ST21NFCA_WR_XCHG_DATA, &fwi, 1, NULL);
        case ST21NFCA_RF_READER_14443_3_A_GATE:
                return nfc_hci_send_cmd(hdev, target->hci_reader_gate,
                                        ST21NFCA_RF_READER_CMD_PRESENCE_CHECK,
                                        NULL, 0, NULL);
        default:
                return -EOPNOTSUPP;
        }
}

static void st21nfca_hci_cmd_received(struct nfc_hci_dev *hdev, u8 pipe, u8 cmd,
                                struct sk_buff *skb)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
        u8 gate = hdev->pipes[pipe].gate;

        pr_debug("cmd: %x\n", cmd);

        switch (cmd) {
        case NFC_HCI_ANY_OPEN_PIPE:
                if (gate != ST21NFCA_APDU_READER_GATE &&
                        hdev->pipes[pipe].dest_host != NFC_HCI_UICC_HOST_ID)
                        info->se_info.count_pipes++;

                if (info->se_info.count_pipes == info->se_info.expected_pipes) {
                        timer_delete_sync(&info->se_info.se_active_timer);
                        info->se_info.se_active = false;
                        info->se_info.count_pipes = 0;
                        complete(&info->se_info.req_completion);
                }
        break;
        }
}

static int st21nfca_admin_event_received(struct nfc_hci_dev *hdev, u8 event,
                                        struct sk_buff *skb)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        pr_debug("admin event: %x\n", event);

        switch (event) {
        case ST21NFCA_EVT_HOT_PLUG:
                if (info->se_info.se_active) {
                        if (!ST21NFCA_EVT_HOT_PLUG_IS_INHIBITED(skb)) {
                                timer_delete_sync(&info->se_info.se_active_timer);
                                info->se_info.se_active = false;
                                complete(&info->se_info.req_completion);
                        } else {
                                mod_timer(&info->se_info.se_active_timer,
                                        jiffies +
                                        msecs_to_jiffies(ST21NFCA_SE_TO_PIPES));
                        }
                }
        break;
        default:
                nfc_err(&hdev->ndev->dev, "Unexpected event on admin gate\n");
        }
        kfree_skb(skb);
        return 0;
}

/*
 * Returns:
 * <= 0: driver handled the event, skb consumed
 *    1: driver does not handle the event, please do standard processing
 */
static int st21nfca_hci_event_received(struct nfc_hci_dev *hdev, u8 pipe,
                                       u8 event, struct sk_buff *skb)
{
        u8 gate = hdev->pipes[pipe].gate;
        u8 host = hdev->pipes[pipe].dest_host;

        pr_debug("hci event: %d gate: %x\n", event, gate);

        switch (gate) {
        case NFC_HCI_ADMIN_GATE:
                return st21nfca_admin_event_received(hdev, event, skb);
        case ST21NFCA_RF_CARD_F_GATE:
                return st21nfca_dep_event_received(hdev, event, skb);
        case ST21NFCA_CONNECTIVITY_GATE:
                return st21nfca_connectivity_event_received(hdev, host,
                                                        event, skb);
        case ST21NFCA_APDU_READER_GATE:
                return st21nfca_apdu_reader_event_received(hdev, event, skb);
        case NFC_HCI_LOOPBACK_GATE:
                return st21nfca_hci_loopback_event_received(hdev, event, skb);
        default:
                return 1;
        }
}

static const struct nfc_hci_ops st21nfca_hci_ops = {
        .open = st21nfca_hci_open,
        .close = st21nfca_hci_close,
        .load_session = st21nfca_hci_load_session,
        .hci_ready = st21nfca_hci_ready,
        .xmit = st21nfca_hci_xmit,
        .start_poll = st21nfca_hci_start_poll,
        .stop_poll = st21nfca_hci_stop_poll,
        .dep_link_up = st21nfca_hci_dep_link_up,
        .dep_link_down = st21nfca_hci_dep_link_down,
        .target_from_gate = st21nfca_hci_target_from_gate,
        .complete_target_discovered = st21nfca_hci_complete_target_discovered,
        .im_transceive = st21nfca_hci_im_transceive,
        .tm_send = st21nfca_hci_tm_send,
        .check_presence = st21nfca_hci_check_presence,
        .event_received = st21nfca_hci_event_received,
        .cmd_received = st21nfca_hci_cmd_received,
        .discover_se = st21nfca_hci_discover_se,
        .enable_se = st21nfca_hci_enable_se,
        .disable_se = st21nfca_hci_disable_se,
        .se_io = st21nfca_hci_se_io,
};

int st21nfca_hci_probe(void *phy_id, const struct nfc_phy_ops *phy_ops,
                       char *llc_name, int phy_headroom, int phy_tailroom,
                       int phy_payload, struct nfc_hci_dev **hdev,
                           struct st21nfca_se_status *se_status)
{
        struct st21nfca_hci_info *info;
        int r = 0;
        int dev_num;
        u32 protocols;
        struct nfc_hci_init_data init_data;
        unsigned long quirks = 0;

        info = kzalloc_obj(struct st21nfca_hci_info);
        if (!info)
                return -ENOMEM;

        info->phy_ops = phy_ops;
        info->phy_id = phy_id;
        info->state = ST21NFCA_ST_COLD;
        mutex_init(&info->info_lock);

        init_data.gate_count = ARRAY_SIZE(st21nfca_gates);

        memcpy(init_data.gates, st21nfca_gates, sizeof(st21nfca_gates));

        /*
         * Session id must include the driver name + i2c bus addr
         * persistent info to discriminate 2 identical chips
         */
        dev_num = find_first_zero_bit(dev_mask, ST21NFCA_NUM_DEVICES);
        if (dev_num >= ST21NFCA_NUM_DEVICES) {
                r = -ENODEV;
                goto err_alloc_hdev;
        }

        set_bit(dev_num, dev_mask);

        scnprintf(init_data.session_id, sizeof(init_data.session_id), "%s%2x",
                  "ST21AH", dev_num);

        protocols = NFC_PROTO_JEWEL_MASK |
            NFC_PROTO_MIFARE_MASK |
            NFC_PROTO_FELICA_MASK |
            NFC_PROTO_ISO14443_MASK |
            NFC_PROTO_ISO14443_B_MASK |
            NFC_PROTO_ISO15693_MASK |
            NFC_PROTO_NFC_DEP_MASK;

        set_bit(NFC_HCI_QUIRK_SHORT_CLEAR, &quirks);

        info->hdev =
            nfc_hci_allocate_device(&st21nfca_hci_ops, &init_data, quirks,
                                    protocols, llc_name,
                                    phy_headroom + ST21NFCA_CMDS_HEADROOM,
                                    phy_tailroom, phy_payload);

        if (!info->hdev) {
                pr_err("Cannot allocate nfc hdev.\n");
                r = -ENOMEM;
                goto err_alloc_hdev;
        }

        info->se_status = se_status;

        nfc_hci_set_clientdata(info->hdev, info);

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

        *hdev = info->hdev;
        st21nfca_dep_init(info->hdev);
        st21nfca_se_init(info->hdev);
        st21nfca_vendor_cmds_init(info->hdev);

        return 0;

err_regdev:
        nfc_hci_free_device(info->hdev);

err_alloc_hdev:
        kfree(info);

        return r;
}
EXPORT_SYMBOL(st21nfca_hci_probe);

void st21nfca_hci_remove(struct nfc_hci_dev *hdev)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        st21nfca_dep_deinit(hdev);
        st21nfca_se_deinit(hdev);
        nfc_hci_unregister_device(hdev);
        nfc_hci_free_device(hdev);
        kfree(info);
}
EXPORT_SYMBOL(st21nfca_hci_remove);

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