// 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 "digital.h"

#define DIGITAL_CMD_SENS_REQ    0x26
#define DIGITAL_CMD_ALL_REQ     0x52
#define DIGITAL_CMD_SEL_REQ_CL1 0x93
#define DIGITAL_CMD_SEL_REQ_CL2 0x95
#define DIGITAL_CMD_SEL_REQ_CL3 0x97

#define DIGITAL_SDD_REQ_SEL_PAR 0x20

#define DIGITAL_SDD_RES_CT  0x88
#define DIGITAL_SDD_RES_LEN 5
#define DIGITAL_SEL_RES_LEN 1

#define DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res) (!((sel_res) & 0x04))
#define DIGITAL_SEL_RES_IS_T2T(sel_res) (!((sel_res) & 0x60))
#define DIGITAL_SEL_RES_IS_T4T(sel_res) ((sel_res) & 0x20)
#define DIGITAL_SEL_RES_IS_NFC_DEP(sel_res) ((sel_res) & 0x40)

#define DIGITAL_SENS_RES_IS_T1T(sens_res) (((sens_res) & 0x0C00) == 0x0C00)
#define DIGITAL_SENS_RES_IS_VALID(sens_res) \
        ((!((sens_res) & 0x001F) && (((sens_res) & 0x0C00) == 0x0C00)) || \
        (((sens_res) & 0x001F) && ((sens_res) & 0x0C00) != 0x0C00))

#define DIGITAL_MIFARE_READ_RES_LEN 16
#define DIGITAL_MIFARE_ACK_RES  0x0A

#define DIGITAL_CMD_SENSB_REQ                   0x05
#define DIGITAL_SENSB_ADVANCED                  BIT(5)
#define DIGITAL_SENSB_EXTENDED                  BIT(4)
#define DIGITAL_SENSB_ALLB_REQ                  BIT(3)
#define DIGITAL_SENSB_N(n)                      ((n) & 0x7)

#define DIGITAL_CMD_SENSB_RES                   0x50

#define DIGITAL_CMD_ATTRIB_REQ                  0x1D
#define DIGITAL_ATTRIB_P1_TR0_DEFAULT           (0x0 << 6)
#define DIGITAL_ATTRIB_P1_TR1_DEFAULT           (0x0 << 4)
#define DIGITAL_ATTRIB_P1_SUPRESS_EOS           BIT(3)
#define DIGITAL_ATTRIB_P1_SUPRESS_SOS           BIT(2)
#define DIGITAL_ATTRIB_P2_LISTEN_POLL_1         (0x0 << 6)
#define DIGITAL_ATTRIB_P2_POLL_LISTEN_1         (0x0 << 4)
#define DIGITAL_ATTRIB_P2_MAX_FRAME_256         0x8
#define DIGITAL_ATTRIB_P4_DID(n)                ((n) & 0xf)

#define DIGITAL_CMD_SENSF_REQ   0x00
#define DIGITAL_CMD_SENSF_RES   0x01

#define DIGITAL_SENSF_RES_MIN_LENGTH 17
#define DIGITAL_SENSF_RES_RD_AP_B1   0x00
#define DIGITAL_SENSF_RES_RD_AP_B2   0x8F

#define DIGITAL_SENSF_REQ_RC_NONE 0
#define DIGITAL_SENSF_REQ_RC_SC   1
#define DIGITAL_SENSF_REQ_RC_AP   2

#define DIGITAL_CMD_ISO15693_INVENTORY_REQ      0x01

#define DIGITAL_ISO15693_REQ_FLAG_DATA_RATE     BIT(1)
#define DIGITAL_ISO15693_REQ_FLAG_INVENTORY     BIT(2)
#define DIGITAL_ISO15693_REQ_FLAG_NB_SLOTS      BIT(5)
#define DIGITAL_ISO15693_RES_FLAG_ERROR         BIT(0)
#define DIGITAL_ISO15693_RES_IS_VALID(flags) \
        (!((flags) & DIGITAL_ISO15693_RES_FLAG_ERROR))

#define DIGITAL_ISO_DEP_I_PCB    0x02
#define DIGITAL_ISO_DEP_PNI(pni) ((pni) & 0x01)

#define DIGITAL_ISO_DEP_PCB_TYPE(pcb) ((pcb) & 0xC0)

#define DIGITAL_ISO_DEP_I_BLOCK 0x00

#define DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb) ((pcb) & 0x08)

static const u8 digital_ats_fsc[] = {
         16,  24,  32,  40,  48,  64,  96, 128,
};

#define DIGITAL_ATS_FSCI(t0) ((t0) & 0x0F)
#define DIGITAL_SENSB_FSCI(pi2) (((pi2) & 0xF0) >> 4)
#define DIGITAL_ATS_MAX_FSC  256

#define DIGITAL_RATS_BYTE1 0xE0
#define DIGITAL_RATS_PARAM 0x80

struct digital_sdd_res {
        u8 nfcid1[4];
        u8 bcc;
} __packed;

struct digital_sel_req {
        u8 sel_cmd;
        u8 b2;
        u8 nfcid1[4];
        u8 bcc;
} __packed;

struct digital_sensb_req {
        u8 cmd;
        u8 afi;
        u8 param;
} __packed;

struct digital_sensb_res {
        u8 cmd;
        u8 nfcid0[4];
        u8 app_data[4];
        u8 proto_info[3];
} __packed;

struct digital_attrib_req {
        u8 cmd;
        u8 nfcid0[4];
        u8 param1;
        u8 param2;
        u8 param3;
        u8 param4;
} __packed;

struct digital_attrib_res {
        u8 mbli_did;
} __packed;

struct digital_sensf_req {
        u8 cmd;
        u8 sc1;
        u8 sc2;
        u8 rc;
        u8 tsn;
} __packed;

struct digital_sensf_res {
        u8 cmd;
        u8 nfcid2[8];
        u8 pad0[2];
        u8 pad1[3];
        u8 mrti_check;
        u8 mrti_update;
        u8 pad2;
        u8 rd[2];
} __packed;

struct digital_iso15693_inv_req {
        u8 flags;
        u8 cmd;
        u8 mask_len;
        u64 mask;
} __packed;

struct digital_iso15693_inv_res {
        u8 flags;
        u8 dsfid;
        u64 uid;
} __packed;

static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
                                   struct nfc_target *target);

int digital_in_iso_dep_pull_sod(struct nfc_digital_dev *ddev,
                                struct sk_buff *skb)
{
        u8 pcb;
        u8 block_type;

        if (skb->len < 1)
                return -EIO;

        pcb = *skb->data;
        block_type = DIGITAL_ISO_DEP_PCB_TYPE(pcb);

        /* No support fo R-block nor S-block */
        if (block_type != DIGITAL_ISO_DEP_I_BLOCK) {
                pr_err("ISO_DEP R-block and S-block not supported\n");
                return -EIO;
        }

        if (DIGITAL_ISO_DEP_BLOCK_HAS_DID(pcb)) {
                pr_err("DID field in ISO_DEP PCB not supported\n");
                return -EIO;
        }

        skb_pull(skb, 1);

        return 0;
}

int digital_in_iso_dep_push_sod(struct nfc_digital_dev *ddev,
                                struct sk_buff *skb)
{
        /*
         * Chaining not supported so skb->len + 1 PCB byte + 2 CRC bytes must
         * not be greater than remote FSC
         */
        if (skb->len + 3 > ddev->target_fsc)
                return -EIO;

        skb_push(skb, 1);

        *skb->data = DIGITAL_ISO_DEP_I_PCB | ddev->curr_nfc_dep_pni;

        ddev->curr_nfc_dep_pni =
                DIGITAL_ISO_DEP_PNI(ddev->curr_nfc_dep_pni + 1);

        return 0;
}

static void digital_in_recv_ats(struct nfc_digital_dev *ddev, void *arg,
                                struct sk_buff *resp)
{
        struct nfc_target *target = arg;
        u8 fsdi;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (resp->len < 2) {
                rc = -EIO;
                goto exit;
        }

        fsdi = DIGITAL_ATS_FSCI(resp->data[1]);
        if (fsdi >= 8)
                ddev->target_fsc = DIGITAL_ATS_MAX_FSC;
        else
                ddev->target_fsc = digital_ats_fsc[fsdi];

        ddev->curr_nfc_dep_pni = 0;

        rc = digital_target_found(ddev, target, NFC_PROTO_ISO14443);

exit:
        dev_kfree_skb(resp);
        kfree(target);

        if (rc)
                digital_poll_next_tech(ddev);
}

static int digital_in_send_rats(struct nfc_digital_dev *ddev,
                                struct nfc_target *target)
{
        int rc;
        struct sk_buff *skb;

        skb = digital_skb_alloc(ddev, 2);
        if (!skb)
                return -ENOMEM;

        skb_put_u8(skb, DIGITAL_RATS_BYTE1);
        skb_put_u8(skb, DIGITAL_RATS_PARAM);

        rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_ats,
                                 target);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_in_recv_sel_res(struct nfc_digital_dev *ddev, void *arg,
                                    struct sk_buff *resp)
{
        struct nfc_target *target = arg;
        int rc;
        u8 sel_res;
        u8 nfc_proto;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
                rc = digital_skb_check_crc_a(resp);
                if (rc) {
                        PROTOCOL_ERR("4.4.1.3");
                        goto exit;
                }
        }

        if (resp->len != DIGITAL_SEL_RES_LEN) {
                rc = -EIO;
                goto exit;
        }

        sel_res = resp->data[0];

        if (!DIGITAL_SEL_RES_NFCID1_COMPLETE(sel_res)) {
                rc = digital_in_send_sdd_req(ddev, target);
                if (rc)
                        goto exit;

                goto exit_free_skb;
        }

        target->sel_res = sel_res;

        if (DIGITAL_SEL_RES_IS_T2T(sel_res)) {
                nfc_proto = NFC_PROTO_MIFARE;
        } else if (DIGITAL_SEL_RES_IS_NFC_DEP(sel_res)) {
                nfc_proto = NFC_PROTO_NFC_DEP;
        } else if (DIGITAL_SEL_RES_IS_T4T(sel_res)) {
                rc = digital_in_send_rats(ddev, target);
                if (rc)
                        goto exit;
                /*
                 * Skip target_found and don't free it for now. This will be
                 * done when receiving the ATS
                 */
                goto exit_free_skb;
        } else {
                rc = -EOPNOTSUPP;
                goto exit;
        }

        rc = digital_target_found(ddev, target, nfc_proto);

exit:
        kfree(target);

exit_free_skb:
        dev_kfree_skb(resp);

        if (rc)
                digital_poll_next_tech(ddev);
}

static int digital_in_send_sel_req(struct nfc_digital_dev *ddev,
                                   struct nfc_target *target,
                                   struct digital_sdd_res *sdd_res)
{
        struct sk_buff *skb;
        struct digital_sel_req *sel_req;
        u8 sel_cmd;
        int rc;

        skb = digital_skb_alloc(ddev, sizeof(struct digital_sel_req));
        if (!skb)
                return -ENOMEM;

        skb_put(skb, sizeof(struct digital_sel_req));
        sel_req = (struct digital_sel_req *)skb->data;

        if (target->nfcid1_len <= 4)
                sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
        else if (target->nfcid1_len < 10)
                sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
        else
                sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;

        sel_req->sel_cmd = sel_cmd;
        sel_req->b2 = 0x70;
        memcpy(sel_req->nfcid1, sdd_res->nfcid1, 4);
        sel_req->bcc = sdd_res->bcc;

        if (DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
                rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
                if (rc)
                        goto exit;
        } else {
                digital_skb_add_crc_a(skb);
        }

        rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sel_res,
                                 target);
exit:
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_in_recv_sdd_res(struct nfc_digital_dev *ddev, void *arg,
                                    struct sk_buff *resp)
{
        struct nfc_target *target = arg;
        struct digital_sdd_res *sdd_res;
        int rc;
        u8 offset, size;
        u8 i, bcc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (resp->len < DIGITAL_SDD_RES_LEN) {
                PROTOCOL_ERR("4.7.2.8");
                rc = -EINVAL;
                goto exit;
        }

        sdd_res = (struct digital_sdd_res *)resp->data;

        for (i = 0, bcc = 0; i < 4; i++)
                bcc ^= sdd_res->nfcid1[i];

        if (bcc != sdd_res->bcc) {
                PROTOCOL_ERR("4.7.2.6");
                rc = -EINVAL;
                goto exit;
        }

        if (sdd_res->nfcid1[0] == DIGITAL_SDD_RES_CT) {
                offset = 1;
                size = 3;
        } else {
                offset = 0;
                size = 4;
        }

        memcpy(target->nfcid1 + target->nfcid1_len, sdd_res->nfcid1 + offset,
               size);
        target->nfcid1_len += size;

        rc = digital_in_send_sel_req(ddev, target, sdd_res);

exit:
        dev_kfree_skb(resp);

        if (rc) {
                kfree(target);
                digital_poll_next_tech(ddev);
        }
}

static int digital_in_send_sdd_req(struct nfc_digital_dev *ddev,
                                   struct nfc_target *target)
{
        int rc;
        struct sk_buff *skb;
        u8 sel_cmd;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                     NFC_DIGITAL_FRAMING_NFCA_STANDARD);
        if (rc)
                return rc;

        skb = digital_skb_alloc(ddev, 2);
        if (!skb)
                return -ENOMEM;

        if (target->nfcid1_len == 0)
                sel_cmd = DIGITAL_CMD_SEL_REQ_CL1;
        else if (target->nfcid1_len == 3)
                sel_cmd = DIGITAL_CMD_SEL_REQ_CL2;
        else
                sel_cmd = DIGITAL_CMD_SEL_REQ_CL3;

        skb_put_u8(skb, sel_cmd);
        skb_put_u8(skb, DIGITAL_SDD_REQ_SEL_PAR);

        rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sdd_res,
                                 target);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_in_recv_sens_res(struct nfc_digital_dev *ddev, void *arg,
                                     struct sk_buff *resp)
{
        struct nfc_target *target = NULL;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (resp->len < sizeof(u16)) {
                rc = -EIO;
                goto exit;
        }

        target = kzalloc_obj(struct nfc_target);
        if (!target) {
                rc = -ENOMEM;
                goto exit;
        }

        target->sens_res = __le16_to_cpu(*(__le16 *)resp->data);

        if (!DIGITAL_SENS_RES_IS_VALID(target->sens_res)) {
                PROTOCOL_ERR("4.6.3.3");
                rc = -EINVAL;
                goto exit;
        }

        if (DIGITAL_SENS_RES_IS_T1T(target->sens_res))
                rc = digital_target_found(ddev, target, NFC_PROTO_JEWEL);
        else
                rc = digital_in_send_sdd_req(ddev, target);

exit:
        dev_kfree_skb(resp);

        if (rc) {
                kfree(target);
                digital_poll_next_tech(ddev);
        }
}

int digital_in_send_sens_req(struct nfc_digital_dev *ddev, u8 rf_tech)
{
        struct sk_buff *skb;
        int rc;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
                                     NFC_DIGITAL_RF_TECH_106A);
        if (rc)
                return rc;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                     NFC_DIGITAL_FRAMING_NFCA_SHORT);
        if (rc)
                return rc;

        skb = digital_skb_alloc(ddev, 1);
        if (!skb)
                return -ENOMEM;

        skb_put_u8(skb, DIGITAL_CMD_SENS_REQ);

        rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sens_res, NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

int digital_in_recv_mifare_res(struct sk_buff *resp)
{
        /* Successful READ command response is 16 data bytes + 2 CRC bytes long.
         * Since the driver can't differentiate a ACK/NACK response from a valid
         * READ response, the CRC calculation must be handled at digital level
         * even if the driver supports it for this technology.
         */
        if (resp->len == DIGITAL_MIFARE_READ_RES_LEN + DIGITAL_CRC_LEN) {
                if (digital_skb_check_crc_a(resp)) {
                        PROTOCOL_ERR("9.4.1.2");
                        return -EIO;
                }

                return 0;
        }

        /* ACK response (i.e. successful WRITE). */
        if (resp->len == 1 && resp->data[0] == DIGITAL_MIFARE_ACK_RES) {
                resp->data[0] = 0;
                return 0;
        }

        /* NACK and any other responses are treated as error. */
        return -EIO;
}

static void digital_in_recv_attrib_res(struct nfc_digital_dev *ddev, void *arg,
                                       struct sk_buff *resp)
{
        struct nfc_target *target = arg;
        struct digital_attrib_res *attrib_res;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (resp->len < sizeof(*attrib_res)) {
                PROTOCOL_ERR("12.6.2");
                rc = -EIO;
                goto exit;
        }

        attrib_res = (struct digital_attrib_res *)resp->data;

        if (attrib_res->mbli_did & 0x0f) {
                PROTOCOL_ERR("12.6.2.1");
                rc = -EIO;
                goto exit;
        }

        rc = digital_target_found(ddev, target, NFC_PROTO_ISO14443_B);

exit:
        dev_kfree_skb(resp);
        kfree(target);

        if (rc)
                digital_poll_next_tech(ddev);
}

static int digital_in_send_attrib_req(struct nfc_digital_dev *ddev,
                               struct nfc_target *target,
                               struct digital_sensb_res *sensb_res)
{
        struct digital_attrib_req *attrib_req;
        struct sk_buff *skb;
        int rc;

        skb = digital_skb_alloc(ddev, sizeof(*attrib_req));
        if (!skb)
                return -ENOMEM;

        attrib_req = skb_put(skb, sizeof(*attrib_req));

        attrib_req->cmd = DIGITAL_CMD_ATTRIB_REQ;
        memcpy(attrib_req->nfcid0, sensb_res->nfcid0,
               sizeof(attrib_req->nfcid0));
        attrib_req->param1 = DIGITAL_ATTRIB_P1_TR0_DEFAULT |
                             DIGITAL_ATTRIB_P1_TR1_DEFAULT;
        attrib_req->param2 = DIGITAL_ATTRIB_P2_LISTEN_POLL_1 |
                             DIGITAL_ATTRIB_P2_POLL_LISTEN_1 |
                             DIGITAL_ATTRIB_P2_MAX_FRAME_256;
        attrib_req->param3 = sensb_res->proto_info[1] & 0x07;
        attrib_req->param4 = DIGITAL_ATTRIB_P4_DID(0);

        rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_attrib_res,
                                 target);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_in_recv_sensb_res(struct nfc_digital_dev *ddev, void *arg,
                                      struct sk_buff *resp)
{
        struct nfc_target *target = NULL;
        struct digital_sensb_res *sensb_res;
        u8 fsci;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (resp->len != sizeof(*sensb_res)) {
                PROTOCOL_ERR("5.6.2.1");
                rc = -EIO;
                goto exit;
        }

        sensb_res = (struct digital_sensb_res *)resp->data;

        if (sensb_res->cmd != DIGITAL_CMD_SENSB_RES) {
                PROTOCOL_ERR("5.6.2");
                rc = -EIO;
                goto exit;
        }

        if (!(sensb_res->proto_info[1] & BIT(0))) {
                PROTOCOL_ERR("5.6.2.12");
                rc = -EIO;
                goto exit;
        }

        if (sensb_res->proto_info[1] & BIT(3)) {
                PROTOCOL_ERR("5.6.2.16");
                rc = -EIO;
                goto exit;
        }

        fsci = DIGITAL_SENSB_FSCI(sensb_res->proto_info[1]);
        if (fsci >= 8)
                ddev->target_fsc = DIGITAL_ATS_MAX_FSC;
        else
                ddev->target_fsc = digital_ats_fsc[fsci];

        target = kzalloc_obj(struct nfc_target);
        if (!target) {
                rc = -ENOMEM;
                goto exit;
        }

        rc = digital_in_send_attrib_req(ddev, target, sensb_res);

exit:
        dev_kfree_skb(resp);

        if (rc) {
                kfree(target);
                digital_poll_next_tech(ddev);
        }
}

int digital_in_send_sensb_req(struct nfc_digital_dev *ddev, u8 rf_tech)
{
        struct digital_sensb_req *sensb_req;
        struct sk_buff *skb;
        int rc;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
                                     NFC_DIGITAL_RF_TECH_106B);
        if (rc)
                return rc;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                     NFC_DIGITAL_FRAMING_NFCB);
        if (rc)
                return rc;

        skb = digital_skb_alloc(ddev, sizeof(*sensb_req));
        if (!skb)
                return -ENOMEM;

        sensb_req = skb_put(skb, sizeof(*sensb_req));

        sensb_req->cmd = DIGITAL_CMD_SENSB_REQ;
        sensb_req->afi = 0x00; /* All families and sub-families */
        sensb_req->param = DIGITAL_SENSB_N(0);

        rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensb_res,
                                 NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_in_recv_sensf_res(struct nfc_digital_dev *ddev, void *arg,
                                   struct sk_buff *resp)
{
        int rc;
        u8 proto;
        struct nfc_target target;
        struct digital_sensf_res *sensf_res;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (resp->len < DIGITAL_SENSF_RES_MIN_LENGTH) {
                rc = -EIO;
                goto exit;
        }

        if (!DIGITAL_DRV_CAPS_IN_CRC(ddev)) {
                rc = digital_skb_check_crc_f(resp);
                if (rc) {
                        PROTOCOL_ERR("6.4.1.8");
                        goto exit;
                }
        }

        skb_pull(resp, 1);

        memset(&target, 0, sizeof(struct nfc_target));

        sensf_res = (struct digital_sensf_res *)resp->data;

        memcpy(target.sensf_res, sensf_res, resp->len);
        target.sensf_res_len = resp->len;

        memcpy(target.nfcid2, sensf_res->nfcid2, NFC_NFCID2_MAXSIZE);
        target.nfcid2_len = NFC_NFCID2_MAXSIZE;

        if (target.nfcid2[0] == DIGITAL_SENSF_NFCID2_NFC_DEP_B1 &&
            target.nfcid2[1] == DIGITAL_SENSF_NFCID2_NFC_DEP_B2)
                proto = NFC_PROTO_NFC_DEP;
        else
                proto = NFC_PROTO_FELICA;

        rc = digital_target_found(ddev, &target, proto);

exit:
        dev_kfree_skb(resp);

        if (rc)
                digital_poll_next_tech(ddev);
}

int digital_in_send_sensf_req(struct nfc_digital_dev *ddev, u8 rf_tech)
{
        struct digital_sensf_req *sensf_req;
        struct sk_buff *skb;
        int rc;
        u8 size;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
        if (rc)
                return rc;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                     NFC_DIGITAL_FRAMING_NFCF);
        if (rc)
                return rc;

        size = sizeof(struct digital_sensf_req);

        skb = digital_skb_alloc(ddev, size);
        if (!skb)
                return -ENOMEM;

        skb_put(skb, size);

        sensf_req = (struct digital_sensf_req *)skb->data;
        sensf_req->cmd = DIGITAL_CMD_SENSF_REQ;
        sensf_req->sc1 = 0xFF;
        sensf_req->sc2 = 0xFF;
        sensf_req->rc = 0;
        sensf_req->tsn = 0;

        *(u8 *)skb_push(skb, 1) = size + 1;

        if (!DIGITAL_DRV_CAPS_IN_CRC(ddev))
                digital_skb_add_crc_f(skb);

        rc = digital_in_send_cmd(ddev, skb, 30, digital_in_recv_sensf_res,
                                 NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_in_recv_iso15693_inv_res(struct nfc_digital_dev *ddev,
                void *arg, struct sk_buff *resp)
{
        struct digital_iso15693_inv_res *res;
        struct nfc_target *target = NULL;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto out_free_skb;
        }

        if (resp->len != sizeof(*res)) {
                rc = -EIO;
                goto out_free_skb;
        }

        res = (struct digital_iso15693_inv_res *)resp->data;

        if (!DIGITAL_ISO15693_RES_IS_VALID(res->flags)) {
                PROTOCOL_ERR("ISO15693 - 10.3.1");
                rc = -EINVAL;
                goto out_free_skb;
        }

        target = kzalloc_obj(*target);
        if (!target) {
                rc = -ENOMEM;
                goto out_free_skb;
        }

        target->is_iso15693 = 1;
        target->iso15693_dsfid = res->dsfid;
        memcpy(target->iso15693_uid, &res->uid, sizeof(target->iso15693_uid));

        rc = digital_target_found(ddev, target, NFC_PROTO_ISO15693);

        kfree(target);

out_free_skb:
        dev_kfree_skb(resp);

        if (rc)
                digital_poll_next_tech(ddev);
}

int digital_in_send_iso15693_inv_req(struct nfc_digital_dev *ddev, u8 rf_tech)
{
        struct digital_iso15693_inv_req *req;
        struct sk_buff *skb;
        int rc;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
                                     NFC_DIGITAL_RF_TECH_ISO15693);
        if (rc)
                return rc;

        rc = digital_in_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                     NFC_DIGITAL_FRAMING_ISO15693_INVENTORY);
        if (rc)
                return rc;

        skb = digital_skb_alloc(ddev, sizeof(*req));
        if (!skb)
                return -ENOMEM;

        skb_put(skb, sizeof(*req) - sizeof(req->mask)); /* No mask */
        req = (struct digital_iso15693_inv_req *)skb->data;

        /* Single sub-carrier, high data rate, no AFI, single slot
         * Inventory command
         */
        req->flags = DIGITAL_ISO15693_REQ_FLAG_DATA_RATE |
                     DIGITAL_ISO15693_REQ_FLAG_INVENTORY |
                     DIGITAL_ISO15693_REQ_FLAG_NB_SLOTS;
        req->cmd = DIGITAL_CMD_ISO15693_INVENTORY_REQ;
        req->mask_len = 0;

        rc = digital_in_send_cmd(ddev, skb, 30,
                                 digital_in_recv_iso15693_inv_res, NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static int digital_tg_send_sel_res(struct nfc_digital_dev *ddev)
{
        struct sk_buff *skb;
        int rc;

        skb = digital_skb_alloc(ddev, 1);
        if (!skb)
                return -ENOMEM;

        skb_put_u8(skb, DIGITAL_SEL_RES_NFC_DEP);

        if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
                digital_skb_add_crc_a(skb);

        rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                     NFC_DIGITAL_FRAMING_NFCA_ANTICOL_COMPLETE);
        if (rc) {
                kfree_skb(skb);
                return rc;
        }

        rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_atr_req,
                                 NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_tg_recv_sel_req(struct nfc_digital_dev *ddev, void *arg,
                                    struct sk_buff *resp)
{
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
                rc = digital_skb_check_crc_a(resp);
                if (rc) {
                        PROTOCOL_ERR("4.4.1.3");
                        goto exit;
                }
        }

        /* Silently ignore SEL_REQ content and send a SEL_RES for NFC-DEP */

        rc = digital_tg_send_sel_res(ddev);

exit:
        if (rc)
                digital_poll_next_tech(ddev);

        dev_kfree_skb(resp);
}

static int digital_tg_send_sdd_res(struct nfc_digital_dev *ddev)
{
        struct sk_buff *skb;
        struct digital_sdd_res *sdd_res;
        int rc, i;

        skb = digital_skb_alloc(ddev, sizeof(struct digital_sdd_res));
        if (!skb)
                return -ENOMEM;

        skb_put(skb, sizeof(struct digital_sdd_res));
        sdd_res = (struct digital_sdd_res *)skb->data;

        sdd_res->nfcid1[0] = 0x08;
        get_random_bytes(sdd_res->nfcid1 + 1, 3);

        sdd_res->bcc = 0;
        for (i = 0; i < 4; i++)
                sdd_res->bcc ^= sdd_res->nfcid1[i];

        rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                NFC_DIGITAL_FRAMING_NFCA_STANDARD_WITH_CRC_A);
        if (rc) {
                kfree_skb(skb);
                return rc;
        }

        rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sel_req,
                                 NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

static void digital_tg_recv_sdd_req(struct nfc_digital_dev *ddev, void *arg,
                                    struct sk_buff *resp)
{
        u8 *sdd_req;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        sdd_req = resp->data;

        if (resp->len < 2 || sdd_req[0] != DIGITAL_CMD_SEL_REQ_CL1 ||
            sdd_req[1] != DIGITAL_SDD_REQ_SEL_PAR) {
                rc = -EINVAL;
                goto exit;
        }

        rc = digital_tg_send_sdd_res(ddev);

exit:
        if (rc)
                digital_poll_next_tech(ddev);

        dev_kfree_skb(resp);
}

static int digital_tg_send_sens_res(struct nfc_digital_dev *ddev)
{
        struct sk_buff *skb;
        u8 *sens_res;
        int rc;

        skb = digital_skb_alloc(ddev, 2);
        if (!skb)
                return -ENOMEM;

        sens_res = skb_put(skb, 2);

        sens_res[0] = (DIGITAL_SENS_RES_NFC_DEP >> 8) & 0xFF;
        sens_res[1] = DIGITAL_SENS_RES_NFC_DEP & 0xFF;

        rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                     NFC_DIGITAL_FRAMING_NFCA_STANDARD);
        if (rc) {
                kfree_skb(skb);
                return rc;
        }

        rc = digital_tg_send_cmd(ddev, skb, 300, digital_tg_recv_sdd_req,
                                 NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

void digital_tg_recv_sens_req(struct nfc_digital_dev *ddev, void *arg,
                              struct sk_buff *resp)
{
        u8 sens_req;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        sens_req = resp->data[0];

        if (!resp->len || (sens_req != DIGITAL_CMD_SENS_REQ &&
            sens_req != DIGITAL_CMD_ALL_REQ)) {
                rc = -EINVAL;
                goto exit;
        }

        rc = digital_tg_send_sens_res(ddev);

exit:
        if (rc)
                digital_poll_next_tech(ddev);

        dev_kfree_skb(resp);
}

static void digital_tg_recv_atr_or_sensf_req(struct nfc_digital_dev *ddev,
                void *arg, struct sk_buff *resp)
{
        if (!IS_ERR(resp) && (resp->len >= 2) &&
                        (resp->data[1] == DIGITAL_CMD_SENSF_REQ))
                digital_tg_recv_sensf_req(ddev, arg, resp);
        else
                digital_tg_recv_atr_req(ddev, arg, resp);

        return;
}

static int digital_tg_send_sensf_res(struct nfc_digital_dev *ddev,
                              struct digital_sensf_req *sensf_req)
{
        struct sk_buff *skb;
        u8 size;
        int rc;
        struct digital_sensf_res *sensf_res;

        size = sizeof(struct digital_sensf_res);

        if (sensf_req->rc == DIGITAL_SENSF_REQ_RC_NONE)
                size -= sizeof(sensf_res->rd);

        skb = digital_skb_alloc(ddev, size);
        if (!skb)
                return -ENOMEM;

        skb_put(skb, size);

        sensf_res = (struct digital_sensf_res *)skb->data;

        memset(sensf_res, 0, size);

        sensf_res->cmd = DIGITAL_CMD_SENSF_RES;
        sensf_res->nfcid2[0] = DIGITAL_SENSF_NFCID2_NFC_DEP_B1;
        sensf_res->nfcid2[1] = DIGITAL_SENSF_NFCID2_NFC_DEP_B2;
        get_random_bytes(&sensf_res->nfcid2[2], 6);

        switch (sensf_req->rc) {
        case DIGITAL_SENSF_REQ_RC_SC:
                sensf_res->rd[0] = sensf_req->sc1;
                sensf_res->rd[1] = sensf_req->sc2;
                break;
        case DIGITAL_SENSF_REQ_RC_AP:
                sensf_res->rd[0] = DIGITAL_SENSF_RES_RD_AP_B1;
                sensf_res->rd[1] = DIGITAL_SENSF_RES_RD_AP_B2;
                break;
        }

        *(u8 *)skb_push(skb, sizeof(u8)) = size + 1;

        if (!DIGITAL_DRV_CAPS_TG_CRC(ddev))
                digital_skb_add_crc_f(skb);

        rc = digital_tg_send_cmd(ddev, skb, 300,
                                 digital_tg_recv_atr_or_sensf_req, NULL);
        if (rc)
                kfree_skb(skb);

        return rc;
}

void digital_tg_recv_sensf_req(struct nfc_digital_dev *ddev, void *arg,
                               struct sk_buff *resp)
{
        struct digital_sensf_req *sensf_req;
        int rc;

        if (IS_ERR(resp)) {
                rc = PTR_ERR(resp);
                resp = NULL;
                goto exit;
        }

        if (!DIGITAL_DRV_CAPS_TG_CRC(ddev)) {
                rc = digital_skb_check_crc_f(resp);
                if (rc) {
                        PROTOCOL_ERR("6.4.1.8");
                        goto exit;
                }
        }

        if (resp->len != sizeof(struct digital_sensf_req) + 1) {
                rc = -EINVAL;
                goto exit;
        }

        skb_pull(resp, 1);
        sensf_req = (struct digital_sensf_req *)resp->data;

        if (sensf_req->cmd != DIGITAL_CMD_SENSF_REQ) {
                rc = -EINVAL;
                goto exit;
        }

        rc = digital_tg_send_sensf_res(ddev, sensf_req);

exit:
        if (rc)
                digital_poll_next_tech(ddev);

        dev_kfree_skb(resp);
}

static int digital_tg_config_nfca(struct nfc_digital_dev *ddev)
{
        int rc;

        rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH,
                                     NFC_DIGITAL_RF_TECH_106A);
        if (rc)
                return rc;

        return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                       NFC_DIGITAL_FRAMING_NFCA_NFC_DEP);
}

int digital_tg_listen_nfca(struct nfc_digital_dev *ddev, u8 rf_tech)
{
        int rc;

        rc = digital_tg_config_nfca(ddev);
        if (rc)
                return rc;

        return digital_tg_listen(ddev, 300, digital_tg_recv_sens_req, NULL);
}

static int digital_tg_config_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
{
        int rc;

        rc = digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_RF_TECH, rf_tech);
        if (rc)
                return rc;

        return digital_tg_configure_hw(ddev, NFC_DIGITAL_CONFIG_FRAMING,
                                       NFC_DIGITAL_FRAMING_NFCF_NFC_DEP);
}

int digital_tg_listen_nfcf(struct nfc_digital_dev *ddev, u8 rf_tech)
{
        int rc;

        rc = digital_tg_config_nfcf(ddev, rf_tech);
        if (rc)
                return rc;

        return digital_tg_listen(ddev, 300, digital_tg_recv_sensf_req, NULL);
}

void digital_tg_recv_md_req(struct nfc_digital_dev *ddev, void *arg,
                            struct sk_buff *resp)
{
        u8 rf_tech;
        int rc;

        if (IS_ERR(resp)) {
                resp = NULL;
                goto exit_free_skb;
        }

        rc = ddev->ops->tg_get_rf_tech(ddev, &rf_tech);
        if (rc)
                goto exit_free_skb;

        switch (rf_tech) {
        case NFC_DIGITAL_RF_TECH_106A:
                rc = digital_tg_config_nfca(ddev);
                if (rc)
                        goto exit_free_skb;
                digital_tg_recv_sens_req(ddev, arg, resp);
                break;
        case NFC_DIGITAL_RF_TECH_212F:
        case NFC_DIGITAL_RF_TECH_424F:
                rc = digital_tg_config_nfcf(ddev, rf_tech);
                if (rc)
                        goto exit_free_skb;
                digital_tg_recv_sensf_req(ddev, arg, resp);
                break;
        default:
                goto exit_free_skb;
        }

        return;

exit_free_skb:
        digital_poll_next_tech(ddev);
        dev_kfree_skb(resp);
}