// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (C) 2014  STMicroelectronics SAS. All rights reserved.
 */

#include <net/nfc/hci.h>

#include "st21nfca.h"

#define ST21NFCA_NFCIP1_INITIATOR 0x00
#define ST21NFCA_NFCIP1_REQ 0xd4
#define ST21NFCA_NFCIP1_RES 0xd5
#define ST21NFCA_NFCIP1_ATR_REQ 0x00
#define ST21NFCA_NFCIP1_ATR_RES 0x01
#define ST21NFCA_NFCIP1_PSL_REQ 0x04
#define ST21NFCA_NFCIP1_PSL_RES 0x05
#define ST21NFCA_NFCIP1_DEP_REQ 0x06
#define ST21NFCA_NFCIP1_DEP_RES 0x07

#define ST21NFCA_NFC_DEP_PFB_PNI(pfb)     ((pfb) & 0x03)
#define ST21NFCA_NFC_DEP_PFB_TYPE(pfb) ((pfb) & 0xE0)
#define ST21NFCA_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
                                ((pfb) & ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT)
#define ST21NFCA_NFC_DEP_DID_BIT_SET(pfb) ((pfb) & 0x04)
#define ST21NFCA_NFC_DEP_NAD_BIT_SET(pfb) ((pfb) & 0x08)
#define ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT 0x10

#define ST21NFCA_NFC_DEP_PFB_IS_TIMEOUT(pfb) \
                                ((pfb) & ST21NFCA_NFC_DEP_PFB_TIMEOUT_BIT)

#define ST21NFCA_NFC_DEP_PFB_I_PDU          0x00
#define ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU   0x40
#define ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU 0x80

#define ST21NFCA_ATR_REQ_MIN_SIZE 17
#define ST21NFCA_ATR_REQ_MAX_SIZE 65
#define ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B 0x30
#define ST21NFCA_GB_BIT  0x02

#define ST21NFCA_EVT_SEND_DATA          0x10
#define ST21NFCA_EVT_FIELD_ON           0x11
#define ST21NFCA_EVT_CARD_DEACTIVATED   0x12
#define ST21NFCA_EVT_CARD_ACTIVATED     0x13
#define ST21NFCA_EVT_FIELD_OFF          0x14

#define ST21NFCA_EVT_CARD_F_BITRATE 0x16
#define ST21NFCA_EVT_READER_F_BITRATE 0x13
#define ST21NFCA_PSL_REQ_SEND_SPEED(brs) (brs & 0x38)
#define ST21NFCA_PSL_REQ_RECV_SPEED(brs) (brs & 0x07)
#define ST21NFCA_PP2LRI(pp) ((pp & 0x30) >> 4)
#define ST21NFCA_CARD_BITRATE_212 0x01
#define ST21NFCA_CARD_BITRATE_424 0x02

#define ST21NFCA_DEFAULT_TIMEOUT 0x0a


#define PROTOCOL_ERR(req) pr_err("%d: ST21NFCA Protocol error: %s\n", \
                                 __LINE__, req)

struct st21nfca_atr_req {
        u8 length;
        u8 cmd0;
        u8 cmd1;
        u8 nfcid3[NFC_NFCID3_MAXSIZE];
        u8 did;
        u8 bsi;
        u8 bri;
        u8 ppi;
        u8 gbi[];
} __packed;

struct st21nfca_atr_res {
        u8 length;
        u8 cmd0;
        u8 cmd1;
        u8 nfcid3[NFC_NFCID3_MAXSIZE];
        u8 did;
        u8 bsi;
        u8 bri;
        u8 to;
        u8 ppi;
        u8 gbi[];
} __packed;

struct st21nfca_psl_req {
        u8 length;
        u8 cmd0;
        u8 cmd1;
        u8 did;
        u8 brs;
        u8 fsl;
} __packed;

struct st21nfca_psl_res {
        u8 length;
        u8 cmd0;
        u8 cmd1;
        u8 did;
} __packed;

struct st21nfca_dep_req_res {
        u8 length;
        u8 cmd0;
        u8 cmd1;
        u8 pfb;
        u8 did;
        u8 nad;
} __packed;

static void st21nfca_tx_work(struct work_struct *work)
{
        struct st21nfca_hci_info *info = container_of(work,
                                                struct st21nfca_hci_info,
                                                dep_info.tx_work);

        struct nfc_dev *dev;
        struct sk_buff *skb;

        dev = info->hdev->ndev;
        skb = info->dep_info.tx_pending;

        device_lock(&dev->dev);

        nfc_hci_send_cmd_async(info->hdev, ST21NFCA_RF_READER_F_GATE,
                        ST21NFCA_WR_XCHG_DATA, skb->data, skb->len,
                        info->async_cb, info);
        device_unlock(&dev->dev);
        kfree_skb(skb);
}

static void st21nfca_im_send_pdu(struct st21nfca_hci_info *info,
                                                struct sk_buff *skb)
{
        info->dep_info.tx_pending = skb;
        schedule_work(&info->dep_info.tx_work);
}

static int st21nfca_tm_send_atr_res(struct nfc_hci_dev *hdev,
                                    struct st21nfca_atr_req *atr_req)
{
        struct st21nfca_atr_res *atr_res;
        struct sk_buff *skb;
        size_t gb_len;
        int r;
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        gb_len = atr_req->length - sizeof(struct st21nfca_atr_req);
        skb = alloc_skb(atr_req->length + 1, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;

        skb_put(skb, sizeof(struct st21nfca_atr_res));

        atr_res = (struct st21nfca_atr_res *)skb->data;
        memset(atr_res, 0, sizeof(struct st21nfca_atr_res));

        atr_res->length = atr_req->length + 1;
        atr_res->cmd0 = ST21NFCA_NFCIP1_RES;
        atr_res->cmd1 = ST21NFCA_NFCIP1_ATR_RES;

        memcpy(atr_res->nfcid3, atr_req->nfcid3, 6);
        atr_res->bsi = 0x00;
        atr_res->bri = 0x00;
        atr_res->to = ST21NFCA_DEFAULT_TIMEOUT;
        atr_res->ppi = ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B;

        if (gb_len) {
                skb_put(skb, gb_len);

                atr_res->ppi |= ST21NFCA_GB_BIT;
                memcpy(atr_res->gbi, atr_req->gbi, gb_len);
                r = nfc_set_remote_general_bytes(hdev->ndev, atr_res->gbi,
                                                  gb_len);
                if (r < 0) {
                        kfree_skb(skb);
                        return r;
                }
        }

        info->dep_info.curr_nfc_dep_pni = 0;

        r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
                                ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
        kfree_skb(skb);
        return r;
}

static int st21nfca_tm_recv_atr_req(struct nfc_hci_dev *hdev,
                                    struct sk_buff *skb)
{
        struct st21nfca_atr_req *atr_req;
        size_t gb_len;
        int r;

        skb_trim(skb, skb->len - 1);

        if (!skb->len)
                return -EIO;

        if (skb->len < ST21NFCA_ATR_REQ_MIN_SIZE)
                return -EPROTO;

        atr_req = (struct st21nfca_atr_req *)skb->data;

        if (atr_req->length < sizeof(struct st21nfca_atr_req))
                return -EPROTO;

        r = st21nfca_tm_send_atr_res(hdev, atr_req);
        if (r)
                return r;

        gb_len = skb->len - sizeof(struct st21nfca_atr_req);

        r = nfc_tm_activated(hdev->ndev, NFC_PROTO_NFC_DEP_MASK,
                              NFC_COMM_PASSIVE, atr_req->gbi, gb_len);
        if (r)
                return r;

        return 0;
}

static int st21nfca_tm_send_psl_res(struct nfc_hci_dev *hdev,
                                    struct st21nfca_psl_req *psl_req)
{
        struct st21nfca_psl_res *psl_res;
        struct sk_buff *skb;
        u8 bitrate[2] = {0, 0};
        int r;

        skb = alloc_skb(sizeof(struct st21nfca_psl_res), GFP_KERNEL);
        if (!skb)
                return -ENOMEM;
        skb_put(skb, sizeof(struct st21nfca_psl_res));

        psl_res = (struct st21nfca_psl_res *)skb->data;

        psl_res->length = sizeof(struct st21nfca_psl_res);
        psl_res->cmd0 = ST21NFCA_NFCIP1_RES;
        psl_res->cmd1 = ST21NFCA_NFCIP1_PSL_RES;
        psl_res->did = psl_req->did;

        r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
                                ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
        if (r < 0)
                goto error;

        /*
         * ST21NFCA only support P2P passive.
         * PSL_REQ BRS value != 0 has only a meaning to
         * change technology to type F.
         * We change to BITRATE 424Kbits.
         * In other case switch to BITRATE 106Kbits.
         */
        if (ST21NFCA_PSL_REQ_SEND_SPEED(psl_req->brs) &&
            ST21NFCA_PSL_REQ_RECV_SPEED(psl_req->brs)) {
                bitrate[0] = ST21NFCA_CARD_BITRATE_424;
                bitrate[1] = ST21NFCA_CARD_BITRATE_424;
        }

        /* Send an event to change bitrate change event to card f */
        r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
                        ST21NFCA_EVT_CARD_F_BITRATE, bitrate, 2);
error:
        kfree_skb(skb);
        return r;
}

static int st21nfca_tm_recv_psl_req(struct nfc_hci_dev *hdev,
                                    struct sk_buff *skb)
{
        struct st21nfca_psl_req *psl_req;

        skb_trim(skb, skb->len - 1);

        if (!skb->len)
                return -EIO;

        psl_req = (struct st21nfca_psl_req *)skb->data;

        if (skb->len < sizeof(struct st21nfca_psl_req))
                return -EIO;

        return st21nfca_tm_send_psl_res(hdev, psl_req);
}

int st21nfca_tm_send_dep_res(struct nfc_hci_dev *hdev, struct sk_buff *skb)
{
        int r;
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        *(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
        *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_RES;
        *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_RES;
        *(u8 *)skb_push(skb, 1) = skb->len;

        r = nfc_hci_send_event(hdev, ST21NFCA_RF_CARD_F_GATE,
                        ST21NFCA_EVT_SEND_DATA, skb->data, skb->len);
        kfree_skb(skb);

        return r;
}
EXPORT_SYMBOL(st21nfca_tm_send_dep_res);

static int st21nfca_tm_recv_dep_req(struct nfc_hci_dev *hdev,
                                    struct sk_buff *skb)
{
        struct st21nfca_dep_req_res *dep_req;
        u8 size;
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        skb_trim(skb, skb->len - 1);

        size = 4;

        dep_req = (struct st21nfca_dep_req_res *)skb->data;
        if (skb->len < size)
                return -EIO;

        if (ST21NFCA_NFC_DEP_DID_BIT_SET(dep_req->pfb))
                size++;
        if (ST21NFCA_NFC_DEP_NAD_BIT_SET(dep_req->pfb))
                size++;

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

        /* Receiving DEP_REQ - Decoding */
        switch (ST21NFCA_NFC_DEP_PFB_TYPE(dep_req->pfb)) {
        case ST21NFCA_NFC_DEP_PFB_I_PDU:
                info->dep_info.curr_nfc_dep_pni =
                                ST21NFCA_NFC_DEP_PFB_PNI(dep_req->pfb);
                break;
        case ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU:
                pr_err("Received a ACK/NACK PDU\n");
                break;
        case ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU:
                pr_err("Received a SUPERVISOR PDU\n");
                break;
        }

        skb_pull(skb, size);

        return nfc_tm_data_received(hdev->ndev, skb);
}

static int st21nfca_tm_event_send_data(struct nfc_hci_dev *hdev,
                                struct sk_buff *skb)
{
        u8 cmd0, cmd1;
        int r;

        cmd0 = skb->data[1];
        switch (cmd0) {
        case ST21NFCA_NFCIP1_REQ:
                cmd1 = skb->data[2];
                switch (cmd1) {
                case ST21NFCA_NFCIP1_ATR_REQ:
                        r = st21nfca_tm_recv_atr_req(hdev, skb);
                        break;
                case ST21NFCA_NFCIP1_PSL_REQ:
                        r = st21nfca_tm_recv_psl_req(hdev, skb);
                        break;
                case ST21NFCA_NFCIP1_DEP_REQ:
                        r = st21nfca_tm_recv_dep_req(hdev, skb);
                        break;
                default:
                        return 1;
                }
                break;
        default:
                return 1;
        }
        return r;
}

/*
 * Returns:
 * <= 0: driver handled the event, skb consumed
 *    1: driver does not handle the event, please do standard processing
 */
int st21nfca_dep_event_received(struct nfc_hci_dev *hdev,
                                u8 event, struct sk_buff *skb)
{
        int r = 0;
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        pr_debug("dep event: %d\n", event);

        switch (event) {
        case ST21NFCA_EVT_CARD_ACTIVATED:
                info->dep_info.curr_nfc_dep_pni = 0;
                break;
        case ST21NFCA_EVT_CARD_DEACTIVATED:
                break;
        case ST21NFCA_EVT_FIELD_ON:
                break;
        case ST21NFCA_EVT_FIELD_OFF:
                break;
        case ST21NFCA_EVT_SEND_DATA:
                r = st21nfca_tm_event_send_data(hdev, skb);
                if (r < 0)
                        return r;
                return 0;
        default:
                nfc_err(&hdev->ndev->dev, "Unexpected event on card f gate\n");
                return 1;
        }
        kfree_skb(skb);
        return r;
}
EXPORT_SYMBOL(st21nfca_dep_event_received);

static void st21nfca_im_send_psl_req(struct nfc_hci_dev *hdev, u8 did, u8 bsi,
                                     u8 bri, u8 lri)
{
        struct sk_buff *skb;
        struct st21nfca_psl_req *psl_req;
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        skb =
            alloc_skb(sizeof(struct st21nfca_psl_req) + 1, GFP_KERNEL);
        if (!skb)
                return;
        skb_reserve(skb, 1);

        skb_put(skb, sizeof(struct st21nfca_psl_req));
        psl_req = (struct st21nfca_psl_req *) skb->data;

        psl_req->length = sizeof(struct st21nfca_psl_req);
        psl_req->cmd0 = ST21NFCA_NFCIP1_REQ;
        psl_req->cmd1 = ST21NFCA_NFCIP1_PSL_REQ;
        psl_req->did = did;
        psl_req->brs = (0x30 & bsi << 4) | (bri & 0x03);
        psl_req->fsl = lri;

        *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;

        st21nfca_im_send_pdu(info, skb);
}

#define ST21NFCA_CB_TYPE_READER_F 1
static void st21nfca_im_recv_atr_res_cb(void *context, struct sk_buff *skb,
                                        int err)
{
        struct st21nfca_hci_info *info = context;
        struct st21nfca_atr_res *atr_res;
        int r;

        if (err != 0)
                return;

        if (!skb)
                return;

        switch (info->async_cb_type) {
        case ST21NFCA_CB_TYPE_READER_F:
                skb_trim(skb, skb->len - 1);
                atr_res = (struct st21nfca_atr_res *)skb->data;
                r = nfc_set_remote_general_bytes(info->hdev->ndev,
                                atr_res->gbi,
                                skb->len - sizeof(struct st21nfca_atr_res));
                if (r < 0)
                        return;

                if (atr_res->to >= 0x0e)
                        info->dep_info.to = 0x0e;
                else
                        info->dep_info.to = atr_res->to + 1;

                info->dep_info.to |= 0x10;

                r = nfc_dep_link_is_up(info->hdev->ndev, info->dep_info.idx,
                                        NFC_COMM_PASSIVE, NFC_RF_INITIATOR);
                if (r < 0)
                        return;

                info->dep_info.curr_nfc_dep_pni = 0;
                if (ST21NFCA_PP2LRI(atr_res->ppi) != info->dep_info.lri)
                        st21nfca_im_send_psl_req(info->hdev, atr_res->did,
                                                atr_res->bsi, atr_res->bri,
                                                ST21NFCA_PP2LRI(atr_res->ppi));
                break;
        default:
                kfree_skb(skb);
                break;
        }
}

int st21nfca_im_send_atr_req(struct nfc_hci_dev *hdev, u8 *gb, size_t gb_len)
{
        struct sk_buff *skb;
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);
        struct st21nfca_atr_req *atr_req;
        struct nfc_target *target;
        uint size;

        info->dep_info.to = ST21NFCA_DEFAULT_TIMEOUT;
        size = ST21NFCA_ATR_REQ_MIN_SIZE + gb_len;
        if (size > ST21NFCA_ATR_REQ_MAX_SIZE) {
                PROTOCOL_ERR("14.6.1.1");
                return -EINVAL;
        }

        skb =
            alloc_skb(sizeof(struct st21nfca_atr_req) + gb_len + 1, GFP_KERNEL);
        if (!skb)
                return -ENOMEM;

        skb_reserve(skb, 1);

        skb_put(skb, sizeof(struct st21nfca_atr_req));

        atr_req = (struct st21nfca_atr_req *)skb->data;
        memset(atr_req, 0, sizeof(struct st21nfca_atr_req));

        atr_req->cmd0 = ST21NFCA_NFCIP1_REQ;
        atr_req->cmd1 = ST21NFCA_NFCIP1_ATR_REQ;
        memset(atr_req->nfcid3, 0, NFC_NFCID3_MAXSIZE);
        target = hdev->ndev->targets;

        if (target->sensf_res_len > 0)
                memcpy(atr_req->nfcid3, target->sensf_res,
                                target->sensf_res_len);
        else
                get_random_bytes(atr_req->nfcid3, NFC_NFCID3_MAXSIZE);

        atr_req->did = 0x0;

        atr_req->bsi = 0x00;
        atr_req->bri = 0x00;
        atr_req->ppi = ST21NFCA_LR_BITS_PAYLOAD_SIZE_254B;
        if (gb_len) {
                atr_req->ppi |= ST21NFCA_GB_BIT;
                skb_put_data(skb, gb, gb_len);
        }
        atr_req->length = sizeof(struct st21nfca_atr_req) + hdev->gb_len;

        *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10; /* timeout */

        info->async_cb_type = ST21NFCA_CB_TYPE_READER_F;
        info->async_cb_context = info;
        info->async_cb = st21nfca_im_recv_atr_res_cb;
        info->dep_info.bri = atr_req->bri;
        info->dep_info.bsi = atr_req->bsi;
        info->dep_info.lri = ST21NFCA_PP2LRI(atr_req->ppi);

        return nfc_hci_send_cmd_async(hdev, ST21NFCA_RF_READER_F_GATE,
                                ST21NFCA_WR_XCHG_DATA, skb->data,
                                skb->len, info->async_cb, info);
}
EXPORT_SYMBOL(st21nfca_im_send_atr_req);

static void st21nfca_im_recv_dep_res_cb(void *context, struct sk_buff *skb,
                                        int err)
{
        struct st21nfca_hci_info *info = context;
        struct st21nfca_dep_req_res *dep_res;

        int size;

        if (err != 0)
                return;

        if (!skb)
                return;

        switch (info->async_cb_type) {
        case ST21NFCA_CB_TYPE_READER_F:
                dep_res = (struct st21nfca_dep_req_res *)skb->data;

                size = 3;
                if (skb->len < size)
                        goto exit;

                if (ST21NFCA_NFC_DEP_DID_BIT_SET(dep_res->pfb))
                        size++;
                if (ST21NFCA_NFC_DEP_NAD_BIT_SET(dep_res->pfb))
                        size++;

                if (skb->len < size)
                        goto exit;

                skb_trim(skb, skb->len - 1);

                /* Receiving DEP_REQ - Decoding */
                switch (ST21NFCA_NFC_DEP_PFB_TYPE(dep_res->pfb)) {
                case ST21NFCA_NFC_DEP_PFB_ACK_NACK_PDU:
                        pr_err("Received a ACK/NACK PDU\n");
                        fallthrough;
                case ST21NFCA_NFC_DEP_PFB_I_PDU:
                        info->dep_info.curr_nfc_dep_pni =
                            ST21NFCA_NFC_DEP_PFB_PNI(dep_res->pfb + 1);
                        size++;
                        skb_pull(skb, size);
                        nfc_tm_data_received(info->hdev->ndev, skb);
                        break;
                case ST21NFCA_NFC_DEP_PFB_SUPERVISOR_PDU:
                        pr_err("Received a SUPERVISOR PDU\n");
                        skb_pull(skb, size);
                        *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
                        *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
                        *(u8 *)skb_push(skb, 1) = skb->len;
                        *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;

                        st21nfca_im_send_pdu(info, skb);
                        break;
                }

                return;
        default:
                break;
        }

exit:
        kfree_skb(skb);
}

int st21nfca_im_send_dep_req(struct nfc_hci_dev *hdev, struct sk_buff *skb)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        info->async_cb_type = ST21NFCA_CB_TYPE_READER_F;
        info->async_cb_context = info;
        info->async_cb = st21nfca_im_recv_dep_res_cb;

        *(u8 *)skb_push(skb, 1) = info->dep_info.curr_nfc_dep_pni;
        *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_DEP_REQ;
        *(u8 *)skb_push(skb, 1) = ST21NFCA_NFCIP1_REQ;
        *(u8 *)skb_push(skb, 1) = skb->len;

        *(u8 *)skb_push(skb, 1) = info->dep_info.to | 0x10;

        return nfc_hci_send_cmd_async(hdev, ST21NFCA_RF_READER_F_GATE,
                                      ST21NFCA_WR_XCHG_DATA,
                                      skb->data, skb->len,
                                      info->async_cb, info);
}
EXPORT_SYMBOL(st21nfca_im_send_dep_req);

void st21nfca_dep_init(struct nfc_hci_dev *hdev)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        INIT_WORK(&info->dep_info.tx_work, st21nfca_tx_work);
        info->dep_info.curr_nfc_dep_pni = 0;
        info->dep_info.idx = 0;
        info->dep_info.to = ST21NFCA_DEFAULT_TIMEOUT;
}
EXPORT_SYMBOL(st21nfca_dep_init);

void st21nfca_dep_deinit(struct nfc_hci_dev *hdev)
{
        struct st21nfca_hci_info *info = nfc_hci_get_clientdata(hdev);

        cancel_work_sync(&info->dep_info.tx_work);
}
EXPORT_SYMBOL(st21nfca_dep_deinit);