// SPDX-License-Identifier: GPL-2.0-only
/*
 * Secure Element driver for STMicroelectronics NFC NCI chip
 *
 * Copyright (C) 2014-2015 STMicroelectronics SAS. All rights reserved.
 */

#include <linux/module.h>
#include <linux/nfc.h>
#include <linux/delay.h>
#include <net/nfc/nci.h>
#include <net/nfc/nci_core.h>

#include "st-nci.h"

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

/* Hosts */
#define ST_NCI_HOST_CONTROLLER_ID     0x00
#define ST_NCI_TERMINAL_HOST_ID       0x01
#define ST_NCI_UICC_HOST_ID           0x02
#define ST_NCI_ESE_HOST_ID            0xc0

/* Gates */
#define ST_NCI_APDU_READER_GATE       0xf0
#define ST_NCI_CONNECTIVITY_GATE      0x41

/* Pipes */
#define ST_NCI_DEVICE_MGNT_PIPE               0x02

/* Connectivity pipe only */
#define ST_NCI_SE_COUNT_PIPE_UICC             0x01
/* Connectivity + APDU Reader pipe */
#define ST_NCI_SE_COUNT_PIPE_EMBEDDED         0x02

#define ST_NCI_SE_TO_HOT_PLUG                   1000 /* msecs */
#define ST_NCI_SE_TO_PIPES                      2000

#define ST_NCI_EVT_HOT_PLUG_IS_INHIBITED(x)   (x->data[0] & 0x80)

#define NCI_HCI_APDU_PARAM_ATR                     0x01
#define NCI_HCI_ADMIN_PARAM_SESSION_IDENTITY       0x01
#define NCI_HCI_ADMIN_PARAM_WHITELIST              0x03
#define NCI_HCI_ADMIN_PARAM_HOST_LIST              0x04

#define ST_NCI_EVT_SE_HARD_RESET                0x20
#define ST_NCI_EVT_TRANSMIT_DATA                0x10
#define ST_NCI_EVT_WTX_REQUEST                  0x11
#define ST_NCI_EVT_SE_SOFT_RESET                0x11
#define ST_NCI_EVT_SE_END_OF_APDU_TRANSFER      0x21
#define ST_NCI_EVT_HOT_PLUG                     0x03

#define ST_NCI_SE_MODE_OFF                    0x00
#define ST_NCI_SE_MODE_ON                     0x01

#define ST_NCI_EVT_CONNECTIVITY       0x10
#define ST_NCI_EVT_TRANSACTION        0x12

#define ST_NCI_DM_GETINFO             0x13
#define ST_NCI_DM_GETINFO_PIPE_LIST   0x02
#define ST_NCI_DM_GETINFO_PIPE_INFO   0x01
#define ST_NCI_DM_PIPE_CREATED        0x02
#define ST_NCI_DM_PIPE_OPEN           0x04
#define ST_NCI_DM_RF_ACTIVE           0x80
#define ST_NCI_DM_DISCONNECT          0x30

#define ST_NCI_DM_IS_PIPE_OPEN(p) \
        ((p & 0x0f) == (ST_NCI_DM_PIPE_CREATED | ST_NCI_DM_PIPE_OPEN))

#define ST_NCI_ATR_DEFAULT_BWI        0x04

/*
 * WT = 2^BWI/10[s], convert into msecs and add a secure
 * room by increasing by 2 this timeout
 */
#define ST_NCI_BWI_TO_TIMEOUT(x)      ((1 << x) * 200)
#define ST_NCI_ATR_GET_Y_FROM_TD(x)   (x >> 4)

/* If TA is present bit 0 is set */
#define ST_NCI_ATR_TA_PRESENT(x) (x & 0x01)
/* If TB is present bit 1 is set */
#define ST_NCI_ATR_TB_PRESENT(x) (x & 0x02)

#define ST_NCI_NUM_DEVICES           256

static DECLARE_BITMAP(dev_mask, ST_NCI_NUM_DEVICES);

/* Here are the mandatory pipe for st_nci */
static struct nci_hci_gate st_nci_gates[] = {
        {NCI_HCI_ADMIN_GATE, NCI_HCI_ADMIN_PIPE,
                                        ST_NCI_HOST_CONTROLLER_ID},
        {NCI_HCI_LINK_MGMT_GATE, NCI_HCI_LINK_MGMT_PIPE,
                                        ST_NCI_HOST_CONTROLLER_ID},
        {ST_NCI_DEVICE_MGNT_GATE, ST_NCI_DEVICE_MGNT_PIPE,
                                        ST_NCI_HOST_CONTROLLER_ID},

        {NCI_HCI_IDENTITY_MGMT_GATE, NCI_HCI_INVALID_PIPE,
                                        ST_NCI_HOST_CONTROLLER_ID},

        /* Secure element pipes are created by secure element host */
        {ST_NCI_CONNECTIVITY_GATE, NCI_HCI_DO_NOT_OPEN_PIPE,
                                        ST_NCI_HOST_CONTROLLER_ID},
        {ST_NCI_APDU_READER_GATE, NCI_HCI_DO_NOT_OPEN_PIPE,
                                        ST_NCI_HOST_CONTROLLER_ID},
};

static u8 st_nci_se_get_bwi(struct nci_dev *ndev)
{
        int i;
        u8 td;
        struct st_nci_info *info = nci_get_drvdata(ndev);

        /* Bits 8 to 5 of the first TB for T=1 encode BWI from zero to nine */
        for (i = 1; i < ST_NCI_ESE_MAX_LENGTH; i++) {
                td = ST_NCI_ATR_GET_Y_FROM_TD(info->se_info.atr[i]);
                if (ST_NCI_ATR_TA_PRESENT(td))
                        i++;
                if (ST_NCI_ATR_TB_PRESENT(td)) {
                        i++;
                        return info->se_info.atr[i] >> 4;
                }
        }
        return ST_NCI_ATR_DEFAULT_BWI;
}

static void st_nci_se_get_atr(struct nci_dev *ndev)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);
        int r;
        struct sk_buff *skb;

        r = nci_hci_get_param(ndev, ST_NCI_APDU_READER_GATE,
                                NCI_HCI_APDU_PARAM_ATR, &skb);
        if (r < 0)
                return;

        if (skb->len <= ST_NCI_ESE_MAX_LENGTH) {
                memcpy(info->se_info.atr, skb->data, skb->len);

                info->se_info.wt_timeout =
                        ST_NCI_BWI_TO_TIMEOUT(st_nci_se_get_bwi(ndev));
        }
        kfree_skb(skb);
}

int st_nci_hci_load_session(struct nci_dev *ndev)
{
        int i, j, r;
        struct sk_buff *skb_pipe_list, *skb_pipe_info;
        struct st_nci_pipe_info *dm_pipe_info;
        u8 pipe_list[] = { ST_NCI_DM_GETINFO_PIPE_LIST,
                        ST_NCI_TERMINAL_HOST_ID};
        u8 pipe_info[] = { ST_NCI_DM_GETINFO_PIPE_INFO,
                        ST_NCI_TERMINAL_HOST_ID, 0};

        /* On ST_NCI device pipes number are dynamics
         * 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 ST_NCI is to:
         * - get a pipe list for each host.
         * (eg: ST_NCI_HOST_CONTROLLER_ID for now).
         * (TODO Later on UICC HOST and eSE HOST)
         * - get pipe information
         * - match retrieved pipe list in st_nci_gates
         * ST_NCI_DEVICE_MGNT_GATE is a proprietary gate
         * with ST_NCI_DEVICE_MGNT_PIPE.
         * Pipe can be closed and need to be open.
         */
        r = nci_hci_connect_gate(ndev, ST_NCI_HOST_CONTROLLER_ID,
                                ST_NCI_DEVICE_MGNT_GATE,
                                ST_NCI_DEVICE_MGNT_PIPE);
        if (r < 0)
                return r;

        /* Get pipe list */
        r = nci_hci_send_cmd(ndev, ST_NCI_DEVICE_MGNT_GATE,
                        ST_NCI_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 = nci_hci_send_cmd(ndev, ST_NCI_DEVICE_MGNT_GATE,
                                        ST_NCI_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)
                 */
                dm_pipe_info = (struct st_nci_pipe_info *)skb_pipe_info->data;
                if (dm_pipe_info->dst_gate_id == ST_NCI_APDU_READER_GATE &&
                    dm_pipe_info->src_host_id == ST_NCI_UICC_HOST_ID) {
                        pr_err("Unexpected apdu_reader pipe on host %x\n",
                               dm_pipe_info->src_host_id);
                        kfree_skb(skb_pipe_info);
                        continue;
                }

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

                if (j < ARRAY_SIZE(st_nci_gates) &&
                    st_nci_gates[j].gate == dm_pipe_info->dst_gate_id &&
                    ST_NCI_DM_IS_PIPE_OPEN(dm_pipe_info->pipe_state)) {
                        ndev->hci_dev->init_data.gates[j].pipe = pipe_info[2];

                        ndev->hci_dev->gate2pipe[st_nci_gates[j].gate] =
                                                pipe_info[2];
                        ndev->hci_dev->pipes[pipe_info[2]].gate =
                                                st_nci_gates[j].gate;
                        ndev->hci_dev->pipes[pipe_info[2]].host =
                                                dm_pipe_info->src_host_id;
                }
                kfree_skb(skb_pipe_info);
        }

        /*
         * 3 gates have a well known pipe ID. Only NCI_HCI_LINK_MGMT_GATE
         * is not yet open at this stage.
         */
        r = nci_hci_connect_gate(ndev, ST_NCI_HOST_CONTROLLER_ID,
                                 NCI_HCI_LINK_MGMT_GATE,
                                 NCI_HCI_LINK_MGMT_PIPE);

        kfree_skb(skb_pipe_list);
        return r;
}
EXPORT_SYMBOL_GPL(st_nci_hci_load_session);

static void st_nci_hci_admin_event_received(struct nci_dev *ndev,
                                              u8 event, struct sk_buff *skb)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);

        switch (event) {
        case ST_NCI_EVT_HOT_PLUG:
                if (info->se_info.se_active) {
                        if (!ST_NCI_EVT_HOT_PLUG_IS_INHIBITED(skb)) {
                                del_timer_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(ST_NCI_SE_TO_PIPES));
                        }
                }
        break;
        default:
                nfc_err(&ndev->nfc_dev->dev, "Unexpected event on admin gate\n");
        }
}

static int st_nci_hci_apdu_reader_event_received(struct nci_dev *ndev,
                                                   u8 event,
                                                   struct sk_buff *skb)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);

        pr_debug("apdu reader gate event: %x\n", event);

        switch (event) {
        case ST_NCI_EVT_TRANSMIT_DATA:
                del_timer_sync(&info->se_info.bwi_timer);
                info->se_info.bwi_active = false;
                info->se_info.cb(info->se_info.cb_context,
                                 skb->data, skb->len, 0);
        break;
        case ST_NCI_EVT_WTX_REQUEST:
                mod_timer(&info->se_info.bwi_timer, jiffies +
                          msecs_to_jiffies(info->se_info.wt_timeout));
        break;
        default:
                nfc_err(&ndev->nfc_dev->dev, "Unexpected event on apdu reader gate\n");
                return 1;
        }

        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 st_nci_hci_connectivity_event_received(struct nci_dev *ndev,
                                                u8 host, u8 event,
                                                struct sk_buff *skb)
{
        int r = 0;
        struct device *dev = &ndev->nfc_dev->dev;
        struct nfc_evt_transaction *transaction;

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

        switch (event) {
        case ST_NCI_EVT_CONNECTIVITY:
                r = nfc_se_connectivity(ndev->nfc_dev, host);
        break;
        case ST_NCI_EVT_TRANSACTION:
                /* According to specification etsi 102 622
                 * 11.2.2.4 EVT_TRANSACTION Table 52
                 * Description  Tag     Length
                 * AID          81      5 to 16
                 * PARAMETERS   82      0 to 255
                 */
                if (skb->len < NFC_MIN_AID_LENGTH + 2 &&
                    skb->data[0] != NFC_EVT_TRANSACTION_AID_TAG)
                        return -EPROTO;

                transaction = devm_kzalloc(dev, skb->len - 2, GFP_KERNEL);
                if (!transaction)
                        return -ENOMEM;

                transaction->aid_len = skb->data[1];
                memcpy(transaction->aid, &skb->data[2], transaction->aid_len);

                /* Check next byte is PARAMETERS tag (82) */
                if (skb->data[transaction->aid_len + 2] !=
                    NFC_EVT_TRANSACTION_PARAMS_TAG)
                        return -EPROTO;

                transaction->params_len = skb->data[transaction->aid_len + 3];
                memcpy(transaction->params, skb->data +
                       transaction->aid_len + 4, transaction->params_len);

                r = nfc_se_transaction(ndev->nfc_dev, host, transaction);
                break;
        default:
                nfc_err(&ndev->nfc_dev->dev, "Unexpected event on connectivity gate\n");
                return 1;
        }
        kfree_skb(skb);
        return r;
}

void st_nci_hci_event_received(struct nci_dev *ndev, u8 pipe,
                                 u8 event, struct sk_buff *skb)
{
        u8 gate = ndev->hci_dev->pipes[pipe].gate;
        u8 host = ndev->hci_dev->pipes[pipe].host;

        switch (gate) {
        case NCI_HCI_ADMIN_GATE:
                st_nci_hci_admin_event_received(ndev, event, skb);
        break;
        case ST_NCI_APDU_READER_GATE:
                st_nci_hci_apdu_reader_event_received(ndev, event, skb);
        break;
        case ST_NCI_CONNECTIVITY_GATE:
                st_nci_hci_connectivity_event_received(ndev, host, event, skb);
        break;
        }
}
EXPORT_SYMBOL_GPL(st_nci_hci_event_received);

void st_nci_hci_cmd_received(struct nci_dev *ndev, u8 pipe, u8 cmd,
                               struct sk_buff *skb)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);
        u8 gate = ndev->hci_dev->pipes[pipe].gate;

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

        switch (cmd) {
        case NCI_HCI_ANY_OPEN_PIPE:
                if (gate != ST_NCI_APDU_READER_GATE &&
                    ndev->hci_dev->pipes[pipe].host != ST_NCI_UICC_HOST_ID)
                        ndev->hci_dev->count_pipes++;

                if (ndev->hci_dev->count_pipes ==
                    ndev->hci_dev->expected_pipes) {
                        del_timer_sync(&info->se_info.se_active_timer);
                        info->se_info.se_active = false;
                        ndev->hci_dev->count_pipes = 0;
                        complete(&info->se_info.req_completion);
                }
        break;
        }
}
EXPORT_SYMBOL_GPL(st_nci_hci_cmd_received);

static int st_nci_control_se(struct nci_dev *ndev, u8 se_idx,
                             u8 state)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);
        int r, i;
        struct sk_buff *sk_host_list;
        u8 host_id;

        switch (se_idx) {
        case ST_NCI_UICC_HOST_ID:
                ndev->hci_dev->count_pipes = 0;
                ndev->hci_dev->expected_pipes = ST_NCI_SE_COUNT_PIPE_UICC;
                break;
        case ST_NCI_ESE_HOST_ID:
                ndev->hci_dev->count_pipes = 0;
                ndev->hci_dev->expected_pipes = ST_NCI_SE_COUNT_PIPE_EMBEDDED;
                break;
        default:
                return -EINVAL;
        }

        /*
         * Wait for an EVT_HOT_PLUG in order to
         * retrieve a relevant host list.
         */
        reinit_completion(&info->se_info.req_completion);
        r = nci_nfcee_mode_set(ndev, se_idx, state);
        if (r != NCI_STATUS_OK)
                return r;

        mod_timer(&info->se_info.se_active_timer, jiffies +
                msecs_to_jiffies(ST_NCI_SE_TO_HOT_PLUG));
        info->se_info.se_active = true;

        /* Ignore return value and check in any case the host_list */
        wait_for_completion_interruptible(&info->se_info.req_completion);

        /* There might be some "collision" after receiving a HOT_PLUG event
         * This may cause the CLF to not answer to the next hci command.
         * There is no possible synchronization to prevent this.
         * Adding a small delay is the only way to solve the issue.
         */
        if (info->se_info.se_status->is_ese_present &&
            info->se_info.se_status->is_uicc_present)
                usleep_range(15000, 20000);

        r = nci_hci_get_param(ndev, NCI_HCI_ADMIN_GATE,
                        NCI_HCI_ADMIN_PARAM_HOST_LIST, &sk_host_list);
        if (r != NCI_HCI_ANY_OK)
                return r;

        for (i = 0; i < sk_host_list->len &&
                sk_host_list->data[i] != se_idx; i++)
                ;
        host_id = sk_host_list->data[i];
        kfree_skb(sk_host_list);
        if (state == ST_NCI_SE_MODE_ON && host_id == se_idx)
                return se_idx;
        else if (state == ST_NCI_SE_MODE_OFF && host_id != se_idx)
                return se_idx;

        return -1;
}

int st_nci_disable_se(struct nci_dev *ndev, u32 se_idx)
{
        int r;

        /*
         * According to upper layer, se_idx == NFC_SE_UICC when
         * info->se_info.se_status->is_uicc_enable is true should never happen
         * Same for eSE.
         */
        r = st_nci_control_se(ndev, se_idx, ST_NCI_SE_MODE_OFF);
        if (r < 0) {
                /* Do best effort to release SWP */
                if (se_idx == NFC_SE_EMBEDDED) {
                        r = nci_hci_send_event(ndev, ST_NCI_APDU_READER_GATE,
                                        ST_NCI_EVT_SE_END_OF_APDU_TRANSFER,
                                        NULL, 0);
                }
                return r;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(st_nci_disable_se);

int st_nci_enable_se(struct nci_dev *ndev, u32 se_idx)
{
        int r;

        /*
         * According to upper layer, se_idx == NFC_SE_UICC when
         * info->se_info.se_status->is_uicc_enable is true should never happen.
         * Same for eSE.
         */
        r = st_nci_control_se(ndev, se_idx, ST_NCI_SE_MODE_ON);
        if (r == ST_NCI_ESE_HOST_ID) {
                st_nci_se_get_atr(ndev);
                r = nci_hci_send_event(ndev, ST_NCI_APDU_READER_GATE,
                                ST_NCI_EVT_SE_SOFT_RESET, NULL, 0);
        }

        if (r < 0) {
                /*
                 * The activation procedure failed, the secure element
                 * is not connected. Remove from the list.
                 */
                nfc_remove_se(ndev->nfc_dev, se_idx);
                return r;
        }

        return 0;
}
EXPORT_SYMBOL_GPL(st_nci_enable_se);

static int st_nci_hci_network_init(struct nci_dev *ndev)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);
        struct core_conn_create_dest_spec_params *dest_params;
        struct dest_spec_params spec_params;
        struct nci_conn_info    *conn_info;
        int r, dev_num;

        dest_params =
                kzalloc(sizeof(struct core_conn_create_dest_spec_params) +
                        sizeof(struct dest_spec_params), GFP_KERNEL);
        if (dest_params == NULL)
                return -ENOMEM;

        dest_params->type = NCI_DESTINATION_SPECIFIC_PARAM_NFCEE_TYPE;
        dest_params->length = sizeof(struct dest_spec_params);
        spec_params.id = ndev->hci_dev->nfcee_id;
        spec_params.protocol = NCI_NFCEE_INTERFACE_HCI_ACCESS;
        memcpy(dest_params->value, &spec_params,
               sizeof(struct dest_spec_params));
        r = nci_core_conn_create(ndev, NCI_DESTINATION_NFCEE, 1,
                                 sizeof(struct core_conn_create_dest_spec_params) +
                                 sizeof(struct dest_spec_params),
                                 dest_params);
        if (r != NCI_STATUS_OK)
                goto free_dest_params;

        conn_info = ndev->hci_dev->conn_info;
        if (!conn_info)
                goto free_dest_params;

        ndev->hci_dev->init_data.gate_count = ARRAY_SIZE(st_nci_gates);
        memcpy(ndev->hci_dev->init_data.gates, st_nci_gates,
               sizeof(st_nci_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, ST_NCI_NUM_DEVICES);
        if (dev_num >= ST_NCI_NUM_DEVICES) {
                r = -ENODEV;
                goto free_dest_params;
        }

        scnprintf(ndev->hci_dev->init_data.session_id,
                  sizeof(ndev->hci_dev->init_data.session_id),
                  "%s%2x", "ST21BH", dev_num);

        r = nci_hci_dev_session_init(ndev);
        if (r != NCI_HCI_ANY_OK)
                goto free_dest_params;

        /*
         * In factory mode, we prevent secure elements activation
         * by disabling nfcee on the current HCI connection id.
         * HCI will be used here only for proprietary commands.
         */
        if (test_bit(ST_NCI_FACTORY_MODE, &info->flags))
                r = nci_nfcee_mode_set(ndev,
                                       ndev->hci_dev->conn_info->dest_params->id,
                                       NCI_NFCEE_DISABLE);
        else
                r = nci_nfcee_mode_set(ndev,
                                       ndev->hci_dev->conn_info->dest_params->id,
                                       NCI_NFCEE_ENABLE);

free_dest_params:
        kfree(dest_params);
        return r;
}

int st_nci_discover_se(struct nci_dev *ndev)
{
        u8 white_list[2];
        int r, wl_size = 0;
        int se_count = 0;
        struct st_nci_info *info = nci_get_drvdata(ndev);

        r = st_nci_hci_network_init(ndev);
        if (r != 0)
                return r;

        if (test_bit(ST_NCI_FACTORY_MODE, &info->flags))
                return 0;

        if (info->se_info.se_status->is_uicc_present)
                white_list[wl_size++] = ST_NCI_UICC_HOST_ID;
        if (info->se_info.se_status->is_ese_present)
                white_list[wl_size++] = ST_NCI_ESE_HOST_ID;

        if (wl_size) {
                r = nci_hci_set_param(ndev, NCI_HCI_ADMIN_GATE,
                                      NCI_HCI_ADMIN_PARAM_WHITELIST,
                                      white_list, wl_size);
                if (r != NCI_HCI_ANY_OK)
                        return r;
        }

        if (info->se_info.se_status->is_uicc_present) {
                nfc_add_se(ndev->nfc_dev, ST_NCI_UICC_HOST_ID, NFC_SE_UICC);
                se_count++;
        }

        if (info->se_info.se_status->is_ese_present) {
                nfc_add_se(ndev->nfc_dev, ST_NCI_ESE_HOST_ID, NFC_SE_EMBEDDED);
                se_count++;
        }

        return !se_count;
}
EXPORT_SYMBOL_GPL(st_nci_discover_se);

int st_nci_se_io(struct nci_dev *ndev, u32 se_idx,
                       u8 *apdu, size_t apdu_length,
                       se_io_cb_t cb, void *cb_context)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);

        switch (se_idx) {
        case ST_NCI_ESE_HOST_ID:
                info->se_info.cb = cb;
                info->se_info.cb_context = cb_context;
                mod_timer(&info->se_info.bwi_timer, jiffies +
                          msecs_to_jiffies(info->se_info.wt_timeout));
                info->se_info.bwi_active = true;
                return nci_hci_send_event(ndev, ST_NCI_APDU_READER_GATE,
                                        ST_NCI_EVT_TRANSMIT_DATA, apdu,
                                        apdu_length);
        default:
                return -ENODEV;
        }
}
EXPORT_SYMBOL(st_nci_se_io);

static void st_nci_se_wt_timeout(struct timer_list *t)
{
        /*
         * No answer from the secure element
         * within the defined timeout.
         * Let's send a reset request as recovery procedure.
         * According to the situation, we first try to send a software reset
         * to the secure element. If the next command is still not
         * answering in time, we send to the CLF a secure element hardware
         * reset request.
         */
        /* hardware reset managed through VCC_UICC_OUT power supply */
        u8 param = 0x01;
        struct st_nci_info *info = from_timer(info, t, se_info.bwi_timer);

        info->se_info.bwi_active = false;

        if (!info->se_info.xch_error) {
                info->se_info.xch_error = true;
                nci_hci_send_event(info->ndlc->ndev, ST_NCI_APDU_READER_GATE,
                                ST_NCI_EVT_SE_SOFT_RESET, NULL, 0);
        } else {
                info->se_info.xch_error = false;
                nci_hci_send_event(info->ndlc->ndev, ST_NCI_DEVICE_MGNT_GATE,
                                ST_NCI_EVT_SE_HARD_RESET, &param, 1);
        }
        info->se_info.cb(info->se_info.cb_context, NULL, 0, -ETIME);
}

static void st_nci_se_activation_timeout(struct timer_list *t)
{
        struct st_nci_info *info = from_timer(info, t,
                                              se_info.se_active_timer);

        info->se_info.se_active = false;

        complete(&info->se_info.req_completion);
}

int st_nci_se_init(struct nci_dev *ndev, struct st_nci_se_status *se_status)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);

        init_completion(&info->se_info.req_completion);
        /* initialize timers */
        timer_setup(&info->se_info.bwi_timer, st_nci_se_wt_timeout, 0);
        info->se_info.bwi_active = false;

        timer_setup(&info->se_info.se_active_timer,
                    st_nci_se_activation_timeout, 0);
        info->se_info.se_active = false;

        info->se_info.xch_error = false;

        info->se_info.wt_timeout =
                ST_NCI_BWI_TO_TIMEOUT(ST_NCI_ATR_DEFAULT_BWI);

        info->se_info.se_status = se_status;

        return 0;
}
EXPORT_SYMBOL(st_nci_se_init);

void st_nci_se_deinit(struct nci_dev *ndev)
{
        struct st_nci_info *info = nci_get_drvdata(ndev);

        if (info->se_info.bwi_active)
                del_timer_sync(&info->se_info.bwi_timer);
        if (info->se_info.se_active)
                del_timer_sync(&info->se_info.se_active_timer);

        info->se_info.se_active = false;
        info->se_info.bwi_active = false;
}
EXPORT_SYMBOL(st_nci_se_deinit);