linux-imx

/*

 * NFC Digital Protocol stack

 * Copyright (c) 2013, Intel Corporation.

 *

 * This program is free software; you can redistribute it and/or modify it

 * under the terms and conditions of the GNU General Public License,

 * version 2, as published by the Free Software Foundation.

 *

 * This program is distributed in the hope it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for

 * more details.

 *

 */

​

#define pr_fmt(fmt) "digital: %s: " fmt, __func__

​

#include <linux/module.h>

​

#include "digital.h"

​

#define DIGITAL_PROTO_NFCA_RF_TECH \

    (NFC_PROTO_JEWEL_MASK | NFC_PROTO_MIFARE_MASK | \

    NFC_PROTO_NFC_DEP_MASK | NFC_PROTO_ISO14443_MASK)

​

#define DIGITAL_PROTO_NFCB_RF_TECH  NFC_PROTO_ISO14443_B_MASK

​

#define DIGITAL_PROTO_NFCF_RF_TECH \

    (NFC_PROTO_FELICA_MASK | NFC_PROTO_NFC_DEP_MASK)

​

#define DIGITAL_PROTO_ISO15693_RF_TECH  NFC_PROTO_ISO15693_MASK

​

/* Delay between each poll frame (ms) */

#define DIGITAL_POLL_INTERVAL 10

​

struct digital_cmd {

    struct list_head queue;

​

    u8 type;

    u8 pending;

​

    u16 timeout;

    struct sk_buff *req;

    struct sk_buff *resp;

    struct digital_tg_mdaa_params *mdaa_params;

​

    nfc_digital_cmd_complete_t cmd_cb;

    void *cb_context;

};

​

struct sk_buff *digital_skb_alloc(struct nfc_digital_dev *ddev,

                  unsigned int len)

{

    struct sk_buff *skb;

​

    skb = alloc_skb(len + ddev->tx_headroom + ddev->tx_tailroom,

            GFP_KERNEL);

    if (skb)

        skb_reserve(skb, ddev->tx_headroom);

​

    return skb;

}

​

void digital_skb_add_crc(struct sk_buff *skb, crc_func_t crc_func, u16 init,

             u8 bitwise_inv, u8 msb_first)

{

    u16 crc;

​

    crc = crc_func(init, skb->data, skb->len);

​

    if (bitwise_inv)

        crc = ~crc;

​

    if (msb_first)

        crc = __fswab16(crc);

​

    skb_put_u8(skb, crc & 0xFF);

    skb_put_u8(skb, (crc >> 8) & 0xFF);

}

​

int digital_skb_check_crc(struct sk_buff *skb, crc_func_t crc_func,

              u16 crc_init, u8 bitwise_inv, u8 msb_first)

{

    int rc;

    u16 crc;

​

    if (skb->len <= 2)

        return -EIO;

​

    crc = crc_func(crc_init, skb->data, skb->len - 2);

​

    if (bitwise_inv)